Pre-Drill EIA study and EMP for Khagarijan Oil and Gas Field Area in Dibrugarh and Tinsukia District of Assam
Draft EIA Report
Prepared for:
Oil India Limited
Prepared by:
SENES Consultants India Pvt. Ltd. Accreditation No. – NABET/EIA/1013/43
November 2013
Pre Drill EIA for Drilling of 30 wells at Khagarijan Field
DRAFT REPORT
M/s Oil India Limited
Pre-Drill EIA study and EMP for Khagarijan Oil and Gas Field Area in
Dibrugarh and Tinsukia District of Assam
The EIA report preparation have been undertaken in compliance with the approved ToR issued by MoEF vide letter no. F. No. J-11011/105/2012- IA II (I) dated 18th July 2012. Information and content provided in the report is factually correct for the purpose and objective for such study undertaken.
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EXECUTIVE SUMMARY
INTRODUCTION The Khagarijan Field of Oil India Limited (OIL) is a part of the Tinsukia PEL area located in Dibrugarh and Tinsukia districts of Assam. OIL had submitted Form-1 of the EIA Notification, along with a Draft Terms of Reference (ToR) for EIA study to MoEF. MoEF has issued approved ToR vide letter No. J-11011/105/2012-IA II (I) dated 18th July 2012. SENES India has been entrusted by OIL to undertake an Environmental Impact Assessment (EIA) study for Khagarijan Field located at the Dibrugarh and Tinsukia districts in Assam. The EIA study comprised of initial scoping & site visit, environmental monitoring & surveys, preparation of draft EIA-EMP report for Public Hearing (PH) and Environmental Clearance.
Block Location & Accessibility The Khagarijan Field of OIL covers approximately 675 sq. km area and is located in Dibrugarh and Tinsukia districts of Assam. The geographic location of the Khagarijan Field is included within the Survey of India’s Topo- Sheet No. 83M2, 83M3, 83M6 and 83M7. The Field is located to the south of the Brahmaputra River. NH 37(AT road) is the most prominent road in the region. The road runs through the southern side of Khagarijan Field, in an East to West orientation. This road connect Tinsukia town located in the south eastern corner of the Field, with Dibrugarh town located on the South Western side, outside the Field. The Northern side of the block is not easily accessible due to the stretch of Brahmaputra River on the West and Dibru-Saikhowa National park in the East. Tinsukia Junction and New Tinsukia Junction are the major railway stations within the Field and are located at the Guwahati-Dibrugarh line of North East Frontier railway whereas Mohanbari Airport is located within the Khagarijan field. Additionally, there are two Air Force bases within the field located at Chabua and Dinjan. Land Lease During the site selection process all the legal requirements will be considered for finalization of surface locations. Once the surface drilling location is finalized, land acquisition will be done including crop compensation. After finalization of drill site, OIL will procure the land from the land owners. The estimated land required per drill site is approximately 2.2 ha. Tentative well coordinates provided by OIL revealed 15 wells within plantation areas of tea garden, 12 wells are located in agriculture land, 2 wells located in household tea garden areas and 1 well within forest land. All the proposed drill sites are away from human habitation; therefore any displacement will not be required for this project. As displacement is not required, resettlement and rehabilitation is not applicable for this project.
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PROJECT ACTIVITIES This activity involves Well site preparation, construction of approach roads Well drilling and testing. Site closure and decommissioning of wells not indicative of potential hydrocarbon reserves.
Site Preparation & Construction Drill site Wells located on the agricultural land have no vegetation; whereas, wells located in the tea garden having tea bushes with shade trees. Site construction work will require clearing of tea bushes and some trees in the drill sites located in the tea garden. Site preparation will involve leveling, filling and consolidation of the site for staging equipment and machinery. Clearance of vegetation is the primary activity that will be undertaken during drill site construction. Following this, top soil will be scraped and stored for future use. The subsequent activities will involve elevating the drill platform by locally available fill material, construction of High Density Polyethylene (HDPE) lined pits for storage of drill cutting, waste mud and drilling wash water, construction of suitable storm water drainage system and construction of approach roads.
Drilling & Testing The drilling of wells is expected to be up to a depth of 4500 meters. Standard Land Rig or Mobile Land Rig with standard water based drilling fluid treatment system will be used for drilling. Drill cuttings generated will be collected and separated using a solid control system and temporarily stored on-site in HDPE lined pits (approximately 800 m3 capacity). Drilling and wash wastewater generated will also be stored at an onsite HDPE lined pit. The water will be adequately treated in a mobile Effluent Treatment Plant (ETP) to ensure conformance to the CPCB onshore oil and gas extraction industry effluent standards before disposal.
Site closure and decommissioning The drill sites will be properly reclaimed and rehabilitated if no commercial reserve has been established. This process will involve decommissioning of rigs and all machineries; disposal of drilling waste as per CPCB guidelines, disposal of fill materials, top soil restoration.
Project Utilities and Resource Requirements Power The power requirement during the site preparation and construction phase for each drill sites will be met through 125 KVA DG sets. Two (2) DG Sets of 1000KW capacity will be required for drilling purposes of which one will be kept as stand by. Lighting and other requirements will be met through 200 KW DG Sets. It is estimated that 3.5 KLD of diesel will be required during drilling phase.
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Water Total water requirement for drill site preparation and construction phase of the project is estimated to be around 10 KLD. The total projected average consumption of water during drilling phase will be about 40 KLD per well including domestic purposes. Water will be sourced through bore well and permission will be taken from Ground Water Authority regarding abstraction of ground water for industrial purposes, if required. Manpower During the drilling phase, about 50 people will be working per shift. This will include technical experts, who will be responsible for various drilling related activities and some local workmen who will be hired from nearby villages for the entire duration of the project.
BASELINE ENVIRONMENTAL STATUS The study of the baseline environmental status helps in assessing the existing environmental conditions and identifying the critical environmental attributes. Baseline environmental study of the Khagarijan Field will comprise study of physical, biological and socio-economic environment where 30 exploratory and developmental wells will be drilled. Primary and secondary data were collected for conduction the EIA study. Physical Environment Climate and Meteorology The study area experiences a humid and warm sub-tropical climate throughout the year except for a cold winter in December till February. Hourly micro-meteorological data collected from primary meteorological station at Tinsukia town during the pre-monsoon reveals that the pre-dominant wind direction is from North West with the wind speed in the range of 1.0-1.5 m/s. Air Quality
The ambient air quality representing PM10, Sulfur Dioxide (SO2), and Nitrogen Dioxide
(NO2) was monitored at eight different locations for 24 hours twice a week during April-
June, 2013.Volatile Organic Carbons (VOCs), Methane (CH4), non-methane hydrocarbons (NMHCs) were monitored at a frequency of once a week for the same period. All the parameters were found to be in compliance to the National Ambient Air Quality Standards
(NAAQS), 2009. The average 24 hourly PM10 at the monitoring locations ranged between 3 3 47.38-71.94µg /m (NAAQS-100 µg/m ). The average 24 hourly NO2 at the monitoring 3 3 locations ranged between 13.70-18.27µg/m (NAAQS-80 µg/m ). The average 24 hourly SO2 concentration at 4 locations were found to be Below Detectable Limit (<4 µg/m3) whereas in other stations the average concentration ranged between 4.00-4.50 µg/m3 (NAAQS-80 µg/m3). Average value for methane hydrocarbon ranged between 2.29-2.83 ppm whereas the mean values of non methane hydrocarbon ranged between 0.38-0.75 ppm. Mean values of VOC at all sampling location varies in the range between 1.13-2.33 ppm.
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Noise Quality The noise quality was monitored for 24 hours at Twenty (20) locations within the Khagarijan Field. Noise monitoring was conducted at areas in proximity to the proposed drill sites. Day time and nighttime equivalent noise levels varied between 50.0-62.7 dBA and 39.4-49.2 dBA respectively. The day time equivalent noise levels at 11 stations out of 20 revealed higher values were compared to the day time noise standards (55 dBA) for residential areas. The night time equivalent noise levels for 4 stations were found to be in exceedance to night time noise standards (45 dBA). Physiography and Geology The Khagarijan Field is included within the depositional plains of the River Brahmaputra and its tributaries. Physiographically, the Field can be classified as Low-lying alluvial belt. Upper Assam Basin is a proven petroliferous basin which represents a classic example of passive continental margin that evolved simultaneously with other east coast basins of India concomitant with rifting followed by drifting of the Indian Plate from eastern Gondwanaland and its subsequent subduction underneath the Burmese and Eurasian plates The basin has thrusted margins on three sides: to the south the Naga Hills Thrust Belt and Manipur Ophiolite Belt; to the east and north the Main Frontal Thrust of the Himalayas, which was active from the mid-Miocene to present day, bends around the Assam Syntaxis. Hydrogeology The annual replenishable ground water sources of Dibrugarh and Tinsukia district as per estimate of CGWB is 1,88,911 hectare metre (ham) and 1,59,036 ham respectively whereas the net ground water availability is found to be 1,79,465 ham and 1,43,132 ham respectively. The stage of groundwater development in Dibrugarh and Tinsukia district is found to be 15% and 12% respectively.
Groundwater Quality Groundwater samples were collected and analyzed as per IS: 10500 from Ten (10) locations within the Field. Almost all the parameters analyzed were under the acceptable and permissible limit of IS: 10500. It has been found that turbidity concentration at 4 locations in exceedance of acceptable limit whereas turbidity concentration at one monitoring location has exceeded the permissible limit. Iron concentration at 3 monitoring location found to be in exceedance of both acceptable and permissible limit. Watershed and Drainage The study area is included under the catchment of the River Brahmaputra which flows from the north eastern side to north western side. The channels traversing through the Field are Dibru River, Dinjan River etc.
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Surface Water Quality Surface water was sampled from Brahmaputra River, Dibru River and Dinjan River. The water samples were analysed and compared with the CPCB Designated Best Use Classification of Surface Waters. The pH of the surface water samples varied from 7.1-7.3. The DO levels at all the locations exhibited values ranging from 6.3-7.0 mg/l. BOD values in all the surface water samples were detected at concentration below 3.00mg/l whereas COD value at the monitoring locations were found to be less than 4.00 mg/l except in one location. Electrical conductivity values of the samples ranged between 0.04-0.11 millisiemens/cm, sodium absorption ratio varied between 0.09-0.19.The total Coliform counts of the surface water samples varied between (11MPN/100ml - 80MPN/100ml). The surface water is primarily being used for irrigation, bathing, cleaning and for catching fish, the obtained results justified their use compliance with the CPCB Water use Criteria. Land Use Majority of the land (28.66%) within the Khagarijan Field is covered by the main course of Brahmaputra River, Dibru River, other small channels, riverbed and water bodies. Tea Garden covers 21.31% of the field whereas 14.8% land is used for agricultural purposes. On the other hand, 9.91% of land is covered by grassland whereas 8.97% of the total field area is covered by Forest area comprising primarily of Dibru-Saikhowa National Park and Padumoni segment of Bherjan-Borajan-Padumoni Sanctuary. Settlement and homestead land plantation comprises about 12% of total area whereas defense installation covers about 1.91 % of total field area.
Soil Quality Soil of Brahmaputra valley of which the Field is a part, is characterized by the presence of fertile alluvial soil. The primary analyses of the soil samples from Agricultural, Tea Garden and Forest Land at 5 locations in the study area shows that the soils are sandy loamy and clayey in nature with a pH range of 3.53-4.99. The soils revealed high available nitrogen content (374.92-490.28mg/kg). The micronutrient levels observed in the soil samples do not indicate any extraordinary enrichment of metals or contamination from any external sources. Natural Hazards The study area lies in Zone V of the Bureau of Indian Standard (BIS) 2000 which might encounter earthquakes of maximum intensity. It was revealed from Flood Hazard Maps (1998-2007) prepared by National Remote Sensing Agency (NRSA) that part of the Khagarijan Field is flood prone, but majority of the proposed exploratory and development wells are not located at the flood prone zones.
Biological Environment Baseline survey and Secondary data received from Forest Department’s Website and other published and unpublished document revealed that about 51 sq.km. area within the Block is included under Dibru-Saikhowa National Park. Along with that, 1.76sq.km. of Padumoni
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Segment of Bherjan-Borajan-Padumoni Sanctuary of Tinsukia district is also located within this Field. Biogeographically, the region exhibits the properties of both the Indian and Malayan Sub-regions. Under the classification of Wild Life Institute, Dehradun, this area falls within North Eastern India Brahmaputra valley Bio-geographical province. About 31 species of Schedule-I animals were reported from the study area which included critically endangered species like Bengal Florican, White Bellied Heron White Ramped Vulture and Slender billed Vulture etc..
Socioeconomic Environment Tinsukia district of Assam comprises of 3 administrative divisions which is further subdivided into 7 Nos. C.D. Blocks. The total population of the district as per 2011 provisional census data is 1316948 with a decadal growth rate of 14.51%. The sex ratio is 948 and the population density is 347 per sq.km. On the other hand, Dibrugarh district of Assam comprises of 7 administrative divisions which is further subdivided into 7 Nos. C.D. Blocks. The total population of the district as per 2011 provisional census data is 1327748 with a decadal growth rate of 11.92%. The sex ratio is 961 and the population density is 392 per sq.km.
Socioeconomic profile Forty Nine (49) villages within the study area were selected for developing the socioeconomic profile of the area. It was seen from the Census Data of 2001, Balijan Tea Estate has the highest population (5124 persons). The highest literacy rate (74.54%) was observed in Dinjoy Satra and the least was found in Nokhroy TE. Major population of the study area villages are either workers in nearby Tea Estates or involved in Agricultural crop cultivation as a source of their livelihood.
Socioeconomic Infrastructure Of the study area villages located in the Field almost all the villages have electricity, drinking water facility and educational facilities. In terms of educational facilities, 37 villages among the identified villages for socioeconomic study are having primary schools. Middle schools and senior secondary schools are present in 11 and 4 villages respectively.
IMPACT ASSESSMENT The potential impacts of the project on different components of the environment was systematically identified and evaluated for significance. The principal concerns that emerged are:
Impact on air Quality The operation of DG sets, movement of vehicles and machineries during construction and drilling at drill sites will result in the generation of air pollutants viz. PM, NOx and SOx which
SENES/K-20197/November 2013 viii Oil India Ltd. Pre Drill EIA for Drilling of 30 wells at Khagarijan Field may affect the ambient air quality temporarily. Air pollutants like NOx will also be generated as a result of flaring of natural gas.
Impact on Noise Quality Operation of heavy machinery/equipments and vehicular movement during site preparatory, road strengthening/construction activities may result in the generation of increased noise levels. Operational phase noise impacts are anticipated from operation of drilling rig and ancillary equipment viz. shale shakers, mud pumps and diesel generators.
Impact on Soil Quality Stripping of top soil will affect the soil fertility of the well sites. Potential impact on soil quality may result from storage and handling of fuel, lubricants and from storage and handling of drilling mud and drill cuttings.
Impact on Topography and drainage Elevating the land to about 1 m from the ground level during site preparation may lead to alteration of onsite micro-drainage pattern. This might lead to the flow of untreated waste water and excess rain water to the adjoining agricultural land thereby adversely impacting the fertility of the soil.
Impact on Water Quality and Hydrology The surface run off from drilling waste (cuttings and drilling mud), hazardous waste (waste oil, used oil etc) and chemical storage facilities on open soil is likely to contaminate if allowed to flow into nearby water bodies viz. natural drainage channels, ponds etc. Possibility of contamination of subsurface and unconfined aquifers may exist if the casing and cementing of the well is not carried out properly leading to infiltration or seeping of drilling chemicals or mud into porous aquifer region.
Impact on Biological Environment Majority of the wells are located on manmade ecological habitat, only one well is located in forest land. Out of 30 planned wells, 14 wells falls within 10km of both Dibru Saikhowa National Park as well as Bherjan Borjan Padumoni Wild life Sanctuary and 14 wells are located within 10km of only Dibru Saikhowa National Park and 1 well is situated within 10 km of only Bherjan Borjan Padumoni Wild Life Sanctuary. Noise generated from drilling activity, lighting at well site, traffic movement will cause disturbance to wildlife. Taking presence of protected ecological habitats and Schedule I in proximity to the proposed well sites, impact on fauna and faunal habitat is considered to be of high significance. Few well sites are located close to the Brahmaputra River or the Maguri-Motapung wetland complex. Therefore, in case of any discharge of untreated waste water from drilling site may result in the possible contamination of receiving streams and their ecological habitat. Surface
SENES/K-20197/November 2013 ix Oil India Ltd. Pre Drill EIA for Drilling of 30 wells at Khagarijan Field runoff during monsoon from the construction site of the wells has the potential to contaminate receiving surface water bodies thereby impacting their aquatic ecology.
Impact on Socio economic Environment The proposed well sites are located both on agricultural land, homestead tea gardens and plantation area of tea estates. The proposed project would not require any displacement of villagers. Impact on socio economic environment is attributed to loss of livelihood, conflicts on job opportunity, disruption of infrastructure, discomfort due to dust and noise, ecological productivity of agricultural land, influx of population etc. The project will benefit the people living in the neighboring villages by giving preference to them in relation to direct & indirect employment associated with the various project activities and boosts the local economy. The proposed project will also involve the improvement of existing road and/or bridge condition thereby enabling the transportation of drilling rig and ancillary equipment.
QUANTITATIVE RISK ASSESSMENT The quantitative risk assessment has been done to provide a systematic analysis of the major risks associated with exploratory and development drilling activities in Khagarijan Field. Oil spills, loss of well control/blow-out and process leaks constitute the major potential hazards of onshore drilling. Based on Frequency Analysis Method, it has been estimated that the likelihood of a blowout is Occasional/Rare at a rate of 7.5X10-2. Thus the Blow out frequency for the proposed project is calculated at 2.25 X 10-1 per well drilled.
ENVIRONMENTAL MANAGEMENT PLAN Site-specific Environment Management Plans (EMP) has been developed to prevent and mitigate significant adverse impacts and accentuate beneficial impacts will be implemented by OIL for the proposed project. The key mitigation measures specific for each management plan have been discussed in the Table below:
Sl. Environment Key Mitigation Measures No Management Plan 1 Pollution The top soil generated from site clearance activities will be stored in Prevention and designated area and stabilized to prevent fugitive dust emissions. Abatement Plan Preventive maintenance of DG sets to be undertaken as per manufacturers schedule to ensure compliance with CPCB specified generator exhaust. All vehicles, equipment and machinery used for construction will be subjected to preventive maintenance as per manufacturer norms. Flaring will be undertaken in accordance with the CPCB Guidelines for Discharge of Gaseous Emissions for Oil & Gas Extraction Industry.
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Sl. Environment Key Mitigation Measures No Management Plan High combustion efficiency, smokeless flare/burner will be used. Installation of acoustic enclosures and mufflers on engine exhaust of DG sets to ensure compliance with generator noise limits specified by CPCB. Setup effective noise barrier at the fence-line of the site. Fuel and chemical storage areas will be paved and properly bunded. Run-off discharges to natural drainage channels/water bodies to conform to CPCB Inland Water Discharge Standards. Proper casing and cementing of drilling well will be done to prevent contamination of sub-surface aquifers. Water based mud to be used as a drilling fluid 2 Waste Use of low toxicity chemicals for the preparation of drilling fluid. Management Plan Storage of drill cuttings in impervious HDPE lined pits Disposal of wash water will be achieved after necessary treatment to comply with the CPCB onshore effluent discharge standard for oil and gas industry. Necessary spill prevention measures viz. spill kit will be made available at the hazardous material storage area The hazardous waste (waste and used oil) will be managed in accordance with Hazardous Waste (Management, Handling & Transboundary Movement) Rules, 2008 The kitchen waste will be disposed in nearest municipal dumping site on a daily basis through approved waste handling contractors The sewage generated will be treated in a combination of septic tank and soak pit. Used batteries will be recycled through the vendors supplying lead acid batteries as required under the Batteries (Management & Handling) Rules, 2001. Recyclables will be periodically sold to local waste recyclers. 3 Wild Life The drill site will be properly fenced (chain-linked) to avoid straying Management Plan of any outsider as well as wildlife; No temporary electric supply connection line from the grid will be laid for the proposed project activity. All electric requirements will be supplied from the internal DG sets. Noise Levels at the drill site will be controlled through selection of low noise generating equipment and installation of sufficient engineering controls viz. mufflers, silencers etc. Movement of heavy vehicles will be restricted at night time In case of any accidental injuries to any wild animal by any project related activity, a Veterinary Doctor’s help will be taken 4 Road Safety & Project vehicular movement involved in sourcing and transportation Traffic of borrow material will be restricted to defined access routes. Management Plan Precautions will be taken to avoid damage to the public access routes
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Sl. Environment Key Mitigation Measures No Management Plan including highways during vehicular movement. Clear signs, flagmen & signal will be set up at major traffic junctions and near sensitive receptors viz. primary schools in discussion with Gram Panchayat and local villagers. Movement of vehicles during night time will be restricted. Speed limits will be maintained by vehicles involved in transportation of raw material and drilling rig. A Journey Management Plan will be formulated and implemented by the contractor to control construction and operational phase traffic. Routine maintenance of project vehicles will be ensured to prevent any abnormal emissions and high noise generation. Adequate training on traffic and road safety operations will be imparted to the drivers of project vehicles. Road safety awareness programs will be organized in coordination with concerned authorities to sensitize target groups viz. school children, commuters on traffic safety rules and signage. 5 Occupational All machines to be used in the construction will conform to the Health & Safety relevant Indian Standards (IS) codes, will be kept in good working Management Plan order, will be regularly inspected and properly maintained as per IS provisions and to the satisfaction of the site Engineer. Contractor workers involved in the handling of construction materials viz. borrow material, cement etc. will be provided with proper PPEs viz. safety boots, nose masks etc. No employee will be exposed to a noise level greater than 85 dB(A) for a duration of more than 8 hours per day. Provision of ear plugs, ear muffs etc. and rotation of workers operating near high noise generating areas. All chemicals and hazardous materials storage container will be properly labeled and marked according to national and internationally recognized requirements and standards. Materials Safety Data Sheets (MSDS) or equivalent data/information in an easily understood language must be readily available to exposed workers and first-aid personnel. The workplace must be equipped with fire detectors, alarm systems and fire-fighting equipments. Equipments shall be periodically inspected and maintained to keep good working condition. Adequate sanitation facilities will be provided onsite for the operational workforce both during construction and operational phase of the project. Training programs will be organized for the operational workforce regarding proper usage of PPEs, handling and storage of fuels and chemicals etc. 6 Management of People from adjoining areas especially given job preference through Social issues and local contractors according to the skill sets possessed. concerns Prior to the commencement of the proposed activity, a consultation program will be conducted by OIL with the target groups and local
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Sl. Environment Key Mitigation Measures No Management Plan authorities. The primary objective of such consultation will be to share with the concerned villagers/stakeholders the objective of the proposed project associated impacts and their mitigation. OIL will give more emphasis and priority on periphery development, development of health facilities and provision for drinking water facility as per Corporate Social Responsibility (CSR) Plan. During the drilling phase and for the rest of the project activities proper safety measures will be undertaken both for transportation as well as the other operations. The drill site would be fenced and gates would be constructed so that the children are refrained from straying into the site. 7 Emergency Drilling rig and related equipments to be used for development Response Plan drilling will be conformed to international standards specified for such equipment. Blow-out preventers and related well control equipment shall be installed, operated, maintained and tested generally in accordance with internationally recognized standards. Appropriate gas and leak detection system will be made available at each of the drilling location. Adequate fire-fighting equipment shall be provided at each drilling site
The EMP has been designed with a flexibility so that it can be monitored and adapted to future changes in project design, scope, or the environment and be seamlessly integrated and implemented by OIL.
PROJECT COST An estimated cost of INR 600 Crore will be expended for the drilling of thirty exploratory and development wells. The budget for implementation of the EMP is INR 153.1 Lakhs.
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Table of Contents 1 Introduction ...... 1 1.1 Background ...... 1 1.2 Objective of the study ...... 1 1.3 Scope of the study ...... 2 1.4 Structure of the EIA report ...... 2 2 Description of the Project ...... 8 2.1 Overview ...... 8 2.2 Objectives and Benefits of Proposed Exploratory, Development and Testing Activities ...... 8 2.3 Khagarijan Field Location & Description ...... 9 2.3.1 Location ...... 9 2.3.2 Accessibility ...... 9 2.4 Khagarijan Field...... 15 2.4.1 Environmental Settings of OIL Field ...... 15 2.4.2 Existing Activity in Oil Field ...... 18 2.5 Well Locations and Environmental Settings...... 18 2.5.1 Location of Wells ...... 18 2.5.2 Environmental Settings ...... 21 2.6 Project Activities And Schedule ...... 28 2.6.1 Pre-drilling Activity ...... 29 2.6.2 Drilling Activity ...... 32 2.6.3 Well Decommissioning ...... 36 2.7 Utilities & Resource Requirements ...... 37 2.7.1 Power Supply ...... 37 2.7.2 Water Consumption and Supply ...... 37 2.7.3 Fuel Consumption ...... 39 2.7.4 Accommodation and Campsites ...... 39 2.7.5 Manpower / Employment ...... 39 2.8 Pollution Sources and Characterization ...... 39 2.8.1 Noise and Vibrations...... 39 2.8.2 Air Emissions ...... 40 2.8.3 Liquid wastes ...... 41 2.8.4 Solid and Hazardous Waste Streams ...... 41 2.9 Drilling Hazards ...... 42
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2.10 Project Cost ...... 42 2.11 HSE Policy ...... 42 3 Description of the Environment ...... 44 3.1 Physical Environment ...... 44 3.1.1 Climate & Meteorology ...... 44 3.1.2 Ambient Air Quality ...... 47 3.1.3 Ambient Noise Quality ...... 54 3.1.4 Physiography and Geology ...... 57 3.1.5 Hydrogeology ...... 60 3.1.6 Ground Water Quality...... 60 3.1.7 Drainage ...... 69 3.1.8 Surface water quality ...... 72 3.1.9 Land-Use and Land Cover ...... 74 3.1.10 Soil Quality ...... 77 3.1.11 Transport and Traffic ...... 81 3.1.12 Natural Hazards ...... 83 3.2 Ecological Environment...... 87 3.2.1 Methodology ...... 87 3.2.2 Terrestrial Ecosystem...... 89 3.2.3 Aquatic Ecosystem...... 101 3.2.4 Agricultural Diversity ...... 102 3.3 Socioeconomic Environment ...... 103 3.3.1 Methodology ...... 103 3.3.2 General Socioeconomic Profile ...... 104 3.3.3 Demographic Profile ...... 108 3.3.4 Socioeconomic Infrastructure ...... 110 3.4 Cultural and historical sites ...... 112 4 Environmental Impact Assessment ...... 114 4.1 Impact Assessment Methodology ...... 114 4.1.1 Impact Criteria and Ranking ...... 114 4.1.2 Impact Significance ...... 115 4.2 Impact Assessment...... 118 4.2.1 Visual Impacts & Aesthetics ...... 118 4.2.2 Impacts on Air Quality...... 119 4.2.3 Impact on Noise Quality ...... 126
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4.2.4 Potential Impact Transport and Traffic ...... 129 4.2.5 Potential Impact on Land Use ...... 129 4.2.6 Impact on Soil Quality ...... 129 4.2.7 Impact on Topography & Drainage ...... 131 4.2.8 Impact on Surface Water Quality ...... 132 4.2.9 Impact on Hydrogeology & Ground Water Quality ...... 134 4.2.10 Impact on Biological Environment ...... 134 4.2.11 Impact on Socioeconomic Environment ...... 137 4.2.12 Impact on Occupational Health and Safety ...... 140 5 Quantitative Risk Assessment...... 142 5.1 Objective of the QRA Study ...... 142 5.2 Risk Assessment Methodology ...... 143 5.2.1 Hazard Identification ...... 144 5.2.2 Frequency Analysis ...... 145 5.2.3 Consequence Analysis ...... 146 5.2.4 Risk Evaluation ...... 147 5.3 Risk Assessment of Identified Project Hazards ...... 149 5.3.1 Blow Outs/Loss of Well Control ...... 149 5.3.2 Process Leaks/Fires ...... 159 5.3.3 Non-process fires/explosions ...... 162 5.4 Disaster Management Plan ...... 163 5.4.1 Objective ...... 163 5.4.2 Purpose ...... 163 5.4.3 Emergency Classification ...... 163 5.4.4 Level 1 - Emergency ...... 164 5.4.5 Level 2 - Emergency ...... 164 5.4.6 Level 3 - Emergency ...... 165 5.4.7 OIL Emergency Response/Crisis Management Team ...... 165 5.4.8 Interface with Other Plans ...... 169 6 Environmental Management Plan & Monitoring Framework ...... 170 6.1 Environment Management Plans ...... 171 6.1.1 Pollution Prevention and Abatement Plan (PPAP) ...... 172 6.1.2 Waste Management Plan...... 177 6.1.3 Storm Water Management Plan ...... 180 6.1.4 Wildlife Management Plan ...... 181
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6.1.5 Road Safety & Traffic Management Plan ...... 182 6.1.6 Occupational Health & Safety Management Plan ...... 184 6.1.7 Management of Social Issues and Concerns ...... 185 6.2 EMP Budget ...... 187 6.3 Environmental Monitoring Program ...... 192 7 Disclosure of Consultants ...... 198
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List of Tables
Table 1-1: Compliance to MoEF ToR ...... 3 Table 2-1: Coordinates of the Khagarijan Field ...... 9 Table 2-2: Coordinates of Tentative Well Locations ...... 18 Table 2-3: Water Requirement Per Well ...... 37 Table 2-4: Typical Noise Emissions from Construction Machinery ...... 40 Table 2-5: Drilling rig and equipment noise level ...... 40 Table 2-6: Liquid Wastes Generated during Drilling and their Disposal ...... 41 Table 2-7: Waste Streams Generated during Drilling and Their Disposal ...... 41 Table 3-1: Ambient Air Quality Results ...... 52 Table 3-2: Groundwater Monitoring Results ...... 64 Table 3-3: Surface Water Quality Results ...... 73 Table 3-4: Soil Analysis Results ...... 80 Table 3-5: Traffic Monitoring Results ...... 82 Table 3-6: Significant Earthquakes in Assam ...... 83 Table 3-7: Flood history of Assam ...... 84 Table 3-8: Proposed Wells located at Flood Prone Locations ...... 85 Table 3-9: Scheduled Animal Species in the Study Area ...... 100 Table 3-10: Projected Population of Assam, Tinsukia and Dibrugarh ...... 108 Table 3-11: List of the study area villages in the Khagarijan Field ...... 108 Table 3-12: Educational Facilities of Tinsukia and Dibrugarh districts ...... 111 Table 4-1: Impact Prediction Criteria ...... 115 Table 4-2: Criteria based Significance of Impacts ...... 116 Table 4-3: Impact Identification Matrix ...... 117 Table 4-4: Input Parameters Considered for Monitoring ...... 120 Table 4-5: Predicted Ground Level Concentrations for Air Pollutants ...... 121 Table 4-6: Construction Equipment Noise Levels ...... 126 Table 4-7: Drilling Rig & Equipment Noise Levels ...... 127 Table 4-8: Impact Significance Matrix (with mitigation) ...... 141 Table 5-1: Frequency Categories and Criteria ...... 146 Table 5-2: Severity Categories and Criteria ...... 147 Table 5-3: Risk Matrix ...... 148 Table 5-4: Risk Criteria and Action Requirements...... 148 Table 5-5: Blow Out Cause Distribution for Failures during Drilling Operations ...... 151 Table 5-6: Pool Fire Modeling Scenarios ...... 153
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Table 5-7: Pool Fire Diameter & Steady State Burning Area ...... 153 Table 5-8: Thermal Radiation Intensity Threshold Values Impact Criterion ...... 154 Table 5-9: Distance to Thermal Radiation Threshold Levels ...... 154 Table 5-10: Jet Fire Modeling Scenarios ...... 155 Table 5-11: Jet Fire Flame Length For Risk Scenarios Considered ...... 156 Table 5-12: Jet Fire Hazard Ranges ...... 156 Table 5-13: Pool Diameter for Oil Spill Risk Scenarios...... 157 Table 5-14: Leak Frequencies for Process Equipment ...... 159 Table 5-15: Project Process Equipment’s Leak Frequencies ...... 160 Table 5-16: Generic Ignition Probabilities ...... 161 Table 5-17: Frequency of Occurrence - Non-Process Fires ...... 162 Table 6-1: Tentative Budget for EMP Implementation ...... 187 Table 6-2: Environmental Management Matrix ...... 189 Table 6-3: Proposed Monitoring Requirements of the Project ...... 193
List of Figures
Figure 2-1: Regional Setting Map of Khagarijan Field ...... 11 Figure 2-2: Khagarijan Field Location Map on Toposheet ...... 12 Figure 2-3: Khagarijan Field Location Map on Satellite Imagery ...... 13 Figure 2-4: Khagarijan Field Accessibility Map ...... 14 Figure 2-5: Environmental Settings of Khagarijan Field ...... 17 Figure 2-6: Location of Proposed Wells on Toposheet ...... 20 Figure 2-7: Typical Drilling Rig Configuration...... 32 Figure 2-8: Drilling Waste Management ...... 34 Figure 2-9: Typical Drilling Fluid Circulation System ...... 35 Figure 2-10: Water Balance Diagram ...... 38 Figure 3-1: Wind Rose Diagram for Pre Monsoon season ...... 47
Figure 3-2: Average PM 10 Values at the Monitoring Locations ...... 48
Figure 3-3: Average PM 2.5 Values at the Monitoring Locations ...... 49
Figure 3-4: Average NO2 Values at the Monitoring Locations ...... 50 Figure 3-5: Day and Night Time Equivalent Noise Levels ...... 55 Figure 3-6: Location of Air, Noise, Meteorology and Traffic Monitoring Locations within the Khagarijan Field ...... 56 Figure 3-7: Topographic Map of Khagarijan Field ...... 59
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Figure 3-8: Location of Groundwater, Surface Water and Soil Monitoring Locations within the Khagarijan Field ...... 68 Figure 3-9: Drainage Map of Khagarijan Field ...... 71 Figure 3-10: Percentage Land Use-Land Cover Distribution of Khagarijan Field ...... 75 Figure 3-11: Land Use Map of Khagarijan Field...... 76 Figure 3-12: Seismic Zone Map of India ...... 83 Figure 3-13: Wells located at the Flood Prone Zones of Dibrugarh and Tinsukia Districts ...86 Figure 3-14: Ecological Sensitivity Map ...... 95 Figure 4-1: Predicted NO2 Concentration Plot (1250 & 250 KVA DG Set) ...... 122 Figure 4-2: Predicted PM Concentration Plot (1250 & 250 KVA DG Set) ...... 123 Figure 4-3: Predicted HC Concentration Plot (1250 & 250 KVA DG Set)...... 124 Figure 4-4: Predicted NO2 Concentration Plot (Flaring) ...... 125 Figure 4-5: Noise Attenuation Plot for Drilling Phase ...... 128 Figure 5-1: Risk Assessment Methodology ...... 144 Figure 5-2: Blow Out Frequencies in Oil & Gas Industry ...... 152 Figure 5-3: Emergency Classification “Decision Tree” ...... 164 Figure 5-4: Emergency Response Levels ...... 165 Figure 5-5: Organizational Structure – Oil India Emergency Response Team ...... 168
List of Photos
Photo 2.1: Nokhroy Tea Estate ...... 16 Photo 2.2:Agricultural lands near Chetiagaon ...... 16 Photo 2.3:Brahmaputra River near Rahmoria ...... 16 Photo 2.4:Dinjan River ...... 16 Photo 2.5: Padumoni Block of Bherjan-Borajan-Padumoni Sanctuary ...... 16 Photo 2.6: AT Road near Dikom ...... 16 Photo 3.1: Meteorological monitoring at Tinsukia ...... 45 Photo 3.2: Air Monitoring at Chetiagaon ...... 51 Photo 3.3: Air Monitoring at Oakland Tea Estate ...... 51 Photo 3.4: Air Monitoring at Guijan ...... 51 Photo 3.5: Air Monitoring at Hazelbank Tea Estate Hospital ...... 51 Photo 3.6: Groundwater sampling at Hazelbank Tea Estate Hospital ...... 63 Photo 3.7: Groundwater sampling near Chabua College ...... 63 Photo 3.8: Groundwater sampling at Guijan No. 8 ...... 63 Photo 3.9: Groundwater sampling at Nahartoli ...... 63 Photo 3.10: Brahmaputra River near Rahmoria ...... 69
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Photo 3.11: Dinjan River ...... 69 Photo 3.12: Dibru River near Guijan ...... 70 Photo 3.13: Dinjan Beel ...... 70 Photo 3.14: Surface water sampling from Dibru River ...... 74 Photo 3.15: Surface water sampling from Brahmaputra River near Oakland Tea Estate ...... 74 Photo 3.16: Surface water sampling from Dinjan ...... 74 Photo 3.17: Surface water sampling from Brahmaputra River near Rahmoria ...... 74 Photo 3.18: Soil sampling from Udalguri tea estate ...... 81 Photo 3.19: Soil sampling from Agricultural land near Poilabari ...... 81 Photo 3.20: Discussion with villagers of Thanai TE Colony...... 113 Photo 3.21: Discussion with villagers at Nunpuria Jadavgaon ...... 113 Photo 3.22: Discussion with villagers at Jeraipathar ...... 113 Photo 3.23: Discussion with villagers at Balijan North Tea Estate ...... 113
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Abbreviation
ALARP As Low As Reasonably Practicable BOD Biological Oxygen Demand BOP Blow out Preventor Cd Cadmium CGWB Central Ground Water Board COD Chemical Oxygen Demand CPCB Central Pollution Control Board Cr Chromium CSR Corporate Social Responsibility Cu Copper DG Diesel Generator DGH Directorate General of Hydrocarbons DMP Disaster Management Plan DO Dissolved Oxygen EC Environmental Clearance EIA Environmental Impact Assessment EMP Environment Management Plan ETP Effluent Treatment Plant FC Forest Clearance GGS/GCS Gas Gathering Station/ Gas Compressor Station GLC Ground Level Concentrations GoI Government of India HC Hydrocarbon HDPE High Density Polyethylene HSD High Speed Diesel HSE Health, Safety and Environmental IMD Indian Meteorological Department IUCN International Union for Conservation of Nature & Natural Resources KCl Potassium Chloride KLD Kilo Liter per Day KW Kilo Watt
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MoEF Ministry of Environment and Forests NAAQS National Ambient Air Quality Standards NABET National Accreditation Board for Education and Training NABL National Accreditation Board for Testing and Calibration Laboratories NELP New Exploration Licensing Policy NH National Highway NOx Oxides of Nitrogen OCS Oil Collection Station O&G Oil & Gas OIL Oil India Limited OSHA Occupational Safety and Health Administration Pb Lead PEL Petroleum Exploration License PM Particulate Matter PPE Personnel Protective Equipments PSC Production Sharing Contract PUCC Pollution Under Control Certificate QCI Quality Council of India QRA Quantitative Risk Assessment RF Reserved Forest
SO2 Sulphur Dioxide SPCB State Pollution Control Board SPL Sound Pressure Level TDS Total Dissolved Solid TG Tea Garden TSS Total Suspended Solids VOC Volatile Organic Compound WBM Water Based Mud WLS Wild Life Sanctuary
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1 Introduction
1.1 BACKGROUND
The Khagarijan Field of Oil India Limited (OIL) is a part of the Tinsukia PEL area located in Dibrugarh and Tinsukia districts of Assam. Extensive seismic surveys and geological studies were carried out in the mid 1990’s following discovery of oil and gas in the neighbouring areas like Chabua, Tengakhat, Dikom etc. Following these studies and surveys several structures had been identified in the area such as Khagorijan, Jeraipathar, Panitola, Matimekhana North, Matimekhana South and Okanimaria, etc. A few of these structures were probed by exploratory drilling and commercial oil was discovered in Khagorijan and Matimekhana North structures. The main hydrocarbon bearing section is Lower Eocene- Paleocene section. In order to explore the area further 3D seismic surveys were carried out in the area The exploration, development and testing proposed in Khagarijan Field is included under activities specified in Schedule (Activity 1b) of the new EIA Notification dated 14th September 2006. It requires Environmental Clearance (EC) from the Ministry of Environment and Forests (MoEF). OIL had submitted Form-1 of the EIA Notification, along with a Draft Terms of Reference (ToR) for EIA study to MoEF. MoEF has issued approved ToR vide letter No. J- 11011/105/2012-IA II (I) dated 18th July 2012. The approved ToR is attached as Annex 1.1 and is in compliance to ToR is presented at Table 1.1. SENES India has been entrusted by OIL to undertake an Environmental Impact Assessment (EIA) study for Khagarijan Field located at the Dibrugarh and Tinsukia districts in Assam. Additionally, as a part of OIL’s Corporate HSE Policy, an EIA study will play an important role in formulating appropriate environmental management response for the proposed exploratory, development and testing project. In this perspective, SENES India has strived to fulfill the project objectives delineated in the section below.
1.2 OBJECTIVE OF THE STUDY The objectives of the EIA study are as follows: Establish the prevailing baseline environmental and socio-economic condition of the Khagarijan Block and its surroundings along with the compliance needs for environmental approvals to carry out exploratory, development and testing drilling activity; Assessing environmental and socioeconomic impacts arising out of the proposed drilling activities;
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Recommend appropriate preventive and mitigation measures to eliminate or minimize pollution, environmental & social disturbances during the life-cycle of the project, ensuring compliance with environmental laws and regulation applicable ; Integrating mitigative measures with existing OIL’s environmental action plans and management systems so that they can be implemented, monitored and suitable corrective action can be taken in case of deviations; Identifying and proposing alternative actions in terms of technology and practices that may help in abating environmental or socio-economic impacts due to the project;
1.3 SCOPE OF THE STUDY The basic scope for this study involves conducting an EIA study to understand the environmental and social impacts of the project and recommend suitable preventive / mitigative actions through the Environment Management Plan (EMP). The scope for the study finalized in close consultation with OIL has been summarized below: Conducting a reconnaissance visit to assess the environmental and socio economic setting of the block; Understanding the existing activities conducted by OIL in the Field posing adverse impacts on environment and socioeconomic integrity of the area; Undertaking site visits for collection of primary and secondary information on environmental and social setting in the Khagarijan Field; Formulating primary environmental monitoring plan and conducting monitoring of the environmental components as per the plan; Carrying out Public Consultation & Public Hearing; Assessing environmental and social impacts; and Formulating Environmental Management Plans
1.4 STRUCTURE OF THE EIA REPORT The EIA report documents the results and findings of the EIA study undertaken by SENES. Subsequent sections of the report present description of the project activities, environmental & social baseline scenario and the outcome of assessment of the impacts and risks that may arise during the lifecycle of the project. Subsequently, the environmental management plan involving mitigation measures that will help in mitigating negative and unacceptable environmental impacts has also been presented. The content of the report is structured as follows: Executive Summary Chapter 1: Introduction Chapter 2: Description of the Project Chapter 3: Description of the Environment Chapter 4: Impact Assessment Chapter 5: Quantitative Risk Assessment
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Chapter 6: Environmental Management Plan & Monitoring Framework Chapter 7: EIA Preparers
List of annexure provided below forms a part of the draft EIA report and has been incorporated at the end of the report as an easy cross-reference.
The EIA report preparation have been undertaken in compliance with the approved ToR issued by MoEF vide letter no. F. No. J-11011/105/2012- IA II (I) dated 18th July 2012 (Annex 1.1). The compliance to the conditions mentioned at the Terms of Reference along with sections of the EIA report reflecting the conditions have been provided at Table 1.1.
TABLE 1-1: COMPLIANCE TO MOEF TOR
Sl. ToR Points Issued Addressed at EIA No The executive summary is added as separate 1. Executive summary of a project document Refer Chapter 2 Project Description; Project description, project objectives 2. and project benefits. Project Objectives and Benefits are provided at Section 2.2. Site details within 1 km of the each The site details of each well is provided at proposed well, any habitation, any other Section 2.5 and the location maps are installation/activity, flora and fauna, provided at Annex 2.1 3. approachability to site, other activities including agriculture/land, satellite imagery for 10 km area. Details of forest land involved in the Only Well 10 is located within forest land. 4. proposed project. A copy of forest Forest Clearance for the well site will be clearance letter, if applicable. obtained prior to site construction Permission from the State Forest Based on the EIA study, all the well Department regarding the impact of the location within 10km of Dibru-Saikhowa proposed plant on the surrounding National Park and Bherjan-Borjan- National Park/Wild life Padumoni Wildlife Sanctuary has already 5. Sanctuary/Reserve Forest/Eco sensitive been identified and Wildlife Clearance for area, if any. Approval obtained from the the same locations will be applied for. State/Central Government under Forest (Conservation Act, 1980 for the forestland shall be submitted. Distance from nearby critically/severely No Critically/Severely Polluted area located 6. polluted area as per Notification dated in Assam. 13th January, 2010, if applicable. OIL will purchase the land from the land owners for the proposed well sites; Does proposal involves rehabilitation 7. and resettlement? If yes, details thereof. No settlement within well location (Refer Section 2.5) therefore rehabilitation, resettlement not required EC was not applicable. CTE & CTO for 8. Environment Clearance for the existing wells/unit, if any, issued by the earlier wells obtained from APCB.
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Sl. ToR Points Issued Addressed at EIA No Ministry, Consent to Operate and Authorization accorded by the AOCB alongwith point wise compliance report. Latest photograph of existing area to be provided. Detailed break up of Project Cost The project cost has been provided at 9. including recurring cost. Section 2.9 Environmental considerations in the The environmental considerations for selection of the drilling locations for selection of the well sites have been which environmental clearance is being provided in Section 2.5.1. 10. sought. Present any analysis suggested for minimizing the foot print giving details of drilling and development options considered. Baseline data collection for air, water The Baseline environmental data have been and soil for one season leaving the provided in Chapter 3 and Further details monsoon season in an area of 10 km 11. have been provided in tabular form in radius with centre of Oil Field as its Annex document centre covering the area of all proposed drilling wells. The topographic map is provided in Figure (i) Topography of the project site. 3.7 (ii) Ambient Air Quality monitoring Ambient Air Quality monitored at 8 at 8 locations for PM10, SO2, NOx, locations is provided at Section 3.1.2 VOCs, Methane and non-methane HC. (iii) Soil sample analysis (physical Soil Quality monitored at 5 locations is and chemical properties) at the areas provided at Section 3.1.10 located at 5 locations. (iv) Ground and surface water quality Groundwater and surface water quality in the vicinity of the proposed wells monitored at 10 and 4 locations respectively site. are provided at Sections 3.1.6 and 3.1.8 (v) Climatology and Meteorology Climate and Meteorology of the project area including wind speed, wind direction, is provided at Section 3.1.1and the detailed
temperature rainfall relative humidity results are presented at Annex 3.2 etc. (vi) Measurement of Noise levels Ambient Noise Quality monitored at 20 within 1 km radius of the proposed locations near the proposed wells is provide wells. at Section 3.1.3 The land use of the Field is provided at (vii) Vegetation and land use; Animal Section 3.1.8. The Land use map is resources provided at Figure 3.11 Incremental GLC Concentrations are Incremental GLC as a result of DG set 12. provided at Section 4.2.2 in Impacts on Air operation. Quality
13. Potential environmental impact Refer Section 4- Impact Assessment envisages during various stages of
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Sl. ToR Points Issued Addressed at EIA No project activities such as site activation, development, operation/ maintenance and decommissioning. Source of water would be from borewell at each well site. If required, OIL will take the Actual source of water and ‘Permission’ necessary permission from the relevant for the drawl of water from the authority if required. 14. Competent Authority. Detailed water
balance, waster water generation and discharge. Water balance is provided at Figure 2.10; Wastewater generation and discharge are provided at Section 2.7.8 - Liquid Wastes Noise abatement measures and Abatement of visual intrusions and noise measures to minimize disturbance due have been provided at Sections 4.2.1 and 15. to light and visual intrusions in case 4.2.3 and also at 6.1.1 Pollution Prevention coastally located. and Abatement Plan Refer Section Table 2.7.8 Liquid wastes and 16. Treatment and disposal of waste water. disposal and Section 6.1.2-Waste Management Plan Refer Section Table 2.7.9 Waste Streams Details of generation, treatment and 17. and Disposal and Section 6.1.2-Waste management of solid waste Management Plan Refer Section Table 2.7.8 Waste Streams 18. Disposal of spent oil and loose. and Disposal and Section 6.1.2-Waste Management Plan Refer Section 2.6.2 for Chemical storage 19. Storage of chemicals and diesel at site. and 2.7.3 for Diesel storage Refer Section 2.6.2-Drilling Activity and 20. Commitment for the use of WBM only Annex 2.2 and Annex 2.3 for mud composition to be used at the wells Mud and cuttings disposal has been Mud make up and mud and cutting provided at Section 2.7.9-Solid and 21. disposal – all options considered shall Hazardous Waste Streams and Section be listed with selective option. 6.1.2-Waste Management plan Refer Section Table 2.7.8 and 2.7.9; Waste Hazardous material usage, storage 22. Streams and Disposal and Section 6.1.2 accounting and disposal. Waste Management Plan Refer Section 6.1.2-Waste Management 23. Disposal of packaging waste from site. Plan Refer Section 6.1.1-Pollution Prevention and Abatement Plan for emergency plans in Oil spill emergency plans in respect of 24. case of oil spills. recovery/ reclamation. Oil spill emergency plans in case of a blow- out have been presented at Section 5.3.1
25. H S emissions control. Natural gas produced from OIL’s existing 2 producing Fields in the area is devoid of
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Sl. ToR Points Issued Addressed at EIA No
any H2S. Refer Natural Gas Analysis Report Annex 2.4 Oil produced at the time of well testing 26. Produced oil handling and storage. operations will be collected in an oil tanker and taken to the nearest OCS. Details of scheme for oil collection Tankers will be provided for collection of 27. system alongwith process flow diagram oil generated during well testing operations. and its capacity. The oil will be transported to OIL OCS. Details of control of air, water and noise Refer Pollution Prevention and Abatement 28. pollution in oil collection system. Plan -Section 6.1.1. Refer Section 6.1.2-Waste Management 29. Disposal of produced/formation water. Plan Whether any burn pits being utilized for Burn pits will not be utilized for well test 30. well test operations. operations Restoration and decommissioning plans Refer Section 2.6.2-Well Decommissioning which shall include mud pits and 31. wastage restoration also and documentation and monitoring of site recovery. Measures to protect ground water and Refer Section 6.1-Pollution Prevention and shallow aquifers from contamination Abatement Plans- Groundwater quality along with its monitoring plan. Action impacts and surface water quality impacts 32. plan should also include storm water runoff during rainy season and measures to prevent runoff which may be contaminated with oil. Risk assessment and mitigation Refer Section Quantitative Risk Assessment measures along with disaster 33. management plan and prevention of blow out. Safety plan to be included for the Tea Refer Section 6.1.7-Management of Social 34. worker in the nearby areas. Issues and Concerns Refer Section 6-Environment Management 35. Environmental management plan. Plan Documentary proof of membership of None 36. common disposal facilities, if any. Details of environmental and safety Refer Box 2.1- OIL Corporate HSE Policy related documentation within the Refer Box 6.1 -OIL Corporate Environment company including documentation and Policy proposed occupational health and safety Refer Section 6.1.6-Occupational Health Surveillance Safety Programme for all 37. and Safety Management Plan personnel at site. This should also include monitoring programme for the Environmental Monitoring Programme has environment. Risk mitigation measures been provided at Table 6.2 should cover for all phases of the site activity including for developing road
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Sl. ToR Points Issued Addressed at EIA No access, drilling of wells, operation and maintenance, waste management, decommissioning etc. Total capital and recurring cost for Cost for environmental control measures 38. environmental control measures. have been provided at Table 6.1. A copy of Corporate Environment OIL’s corporate Environment Policy has Policy of the OIL as per the Ministry’s been provided at Box 5.1 39. O.M. No. J-11013/41/2006-IA.II (I) dated 26th April, 2011 available on the Ministry’s website. Any litigation pending against the No litigation is pending against the project project and or any direction/order 40. passed by any court of law against the project. If so details thereof. A tabular chart with index for point- Provided at Table 1.1 41. wise compliance of above TORs.
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2 Description of the Project
2.1 OVERVIEW Oil India Limited was incorporated on 18th February 1959 to expand and develop the newly discovered oil fields of Naharkatia and Moran in the Indian North East. In 1961, it became a joint venture company between the Indian Government and Burmah Oil Company Limited, UK. In 1981, OIL became a wholly-owned Government of India enterprise. Today, OIL is a premier Indian National Oil Company engaged in the business of exploration, development and production of crude oil and natural gas, transportation of crude oil and production of LPG. OIL has over 1 lakh sq. km. of PEL/ML areas for its exploration and production activities, most of it in the Indian North East, which accounts for its entire crude oil production and majority of gas production. Rajasthan is the other producing area of OIL, contributing 10 per cent of its total gas production. Additionally, OIL’s exploration activities are spread over onshore areas of Ganga Valley and Mahanadi. OIL also has participating interest in NELP exploration blocks in Mahanadi Offshore, Mumbai Deepwater, Krishna Godavari Deepwater, etc. as well as various overseas projects in Libya, Gabon, Iran, Nigeria and Sudan. In a recent CRISIL-India Today survey, OIL was adjudged as one of the five best major PSUs and one of three best energy sector PSUs in the country. OIL has drilled 6 wells in Khagarijan oil & gas field for exploration of hydrocarbon prior to implementation of EIA Notification, 2006 and those exploration activity indicated presence of hydrocarbon in this field. During the current program OIL is planning to drill 30 more wells to explore & develop the field and enhance production.
2.2 OBJECTIVES AND BENEFITS OF PROPOSED EXPLORATORY, DEVELOPMENT AND TESTING ACTIVITIES
Project Objectives
Objectives of the proposed drilling activities are summarized below: To drill and evaluate hydrocarbons’ prospects safely without putting significant impact on the environment. To decide optimum locations of next few wells to be drilled based on geological models and Geotechnical investigations and Geological mapping.
Project Benefits The project will ultimately cater to fulfill the energy requirement of India. The dependency of India on other countries will be lessened to an extent. Additionally, the project will benefit people living in neighboring villages in relation to direct & indirect employment associated
SENES/K-20197/ November 2013 8 Oil India Ltd. Pre Drill EIA for Drilling of 30 wells at Khagarijan Field with various project activities and will boost the local economy. The benefits of the project are listed below Provision of more loyalty to Assam Government and more cess to Govt. of India Provision of more employment opportunity to local people Development of infrastructure (roads, culverts, bridges, schools etc.) in the area Increase in business opportunity for the local people Energy security for the country Programs related to livelihood generation, health improvement as per OIL’s Corporate Social Responsibility (CSR) programmes
2.3 KHAGARIJAN FIELD LOCATION & DESCRIPTION
2.3.1 Location The Khagarijan Field of OIL covers approximately 675 sq. km area and is located in Dibrugarh and Tinsukia districts of Assam. Regional setting of the hydrocarbon field is shown in Figure 2.1. The geographic location of the Khagarijan Field is included within the Survey of India’s Topo- Sheet No. 83M2, 83M3, 83M6 and 83M7. The Field is located to the South of the Brahmaputra River. Coordinates of the Khagarijan Field are given in Table 2.1. The Khagarijan Field location map superimposed on Toposheet and satellite imagery is shown in Figure 2.2 and Figure 2.3 respectively. TABLE 2-1: COORDINATES OF THE KHAGARIJAN FIELD D Longitude (East) Latitude (North) Pt. Deg. Min. Deg. Min. A 27 37 94 58 B 27 37 95 21 C 27 28.5 95 21 D 27 28.5 94 58
2.3.2 Accessibility
Roads NH 37(AT road) is the most prominent road in the region. The road runs through the southern side of Khagarijan Field, in an east to west orientation. This road connect Tinsukia town located in the south eastern corner of the Field, with Dibrugarh town located on the south western side, outside the Field. PWD roads arising from the AT road leads northward up to Brahmaputra River/Dibru River making the interior of the Field accessible. Notable among the small roads are Bilu road, which leads to Dibrugarh Airport, another such road is Dinjan- Balijan road which leads to Balijan (located more or less centrally in the block) and Rangagora Road that arises from Tinsukia town and leads to Guijan. The extreme northern
SENES/K-20197/ November 2013 9 Oil India Ltd. Pre Drill EIA for Drilling of 30 wells at Khagarijan Field side of the block is not easily accessible as it is mainly Brahmaputra River on the west and Dibru-Saikhowa National park in the east. Railway Tinsukia Junction and New Tinsukia Junction are the major railway stations within the Field and are located at the Guwahati-Dibrugarh line of North East Frontier railway. The Guwahati Dibrugarh line traverses through the south of the Khagarijan Field. Other railways stations located within or close to the Field are Lahoal, Dikom, Chabua, Panitola etc. Airport Mohanbari Airport is located within the Khagarijan Field which is primarily used for commercial flights. There are also two Air Force bases within the Field located at Chabua and Dinjan Figure 2.4.
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FIGURE 2-1: REGIONAL SETTING MAP OF KHAGARIJAN FIELD
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FIGURE 2-2: KHAGARIJAN FIELD LOCATION MAP ON TOPOSHEET
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FIGURE 2-3: KHAGARIJAN FIELD LOCATION MAP ON SATELLITE IMAGERY
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FIGURE 2-4: KHAGARIJAN FIELD ACCESSIBILITY MAP
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2.4 KHAGARIJAN FIELD
2.4.1 Environmental Settings of OIL Field The Khagarijan Field is located in Dibrugarh and Tinsukia districts of Assam and spreads over an area of about 675 sq. km. The Field is located in areas of Guijan and Itakhuli Development Blocks of Tinsukia district and Chabua, Panitola and Lahoal Development Blocks of Dibrugarh district. The key physical features (Refer Figure 2.5) of Khagarijan Field have been described below: The Field is rectangular in shape having a dimension of approximately 40 km in length and 17 km in breadth. The northern half of the Field is mainly covered under the course of the Brahmaputra River (at the north-west) and Dibru-Saikhowa National Park (at the north-east). The southern boundary of the Field is more or less aligned with the NH 37 with towns like Tinsukia and Dibrugarh located near the south- eastern and south-western boundary respectively. The Khagarijan Field is located in the drainage basin of Brahmaputra River. Apart from Brahmaputra (flowing through North West), other major river in the block is the Dinjan river that flows more or less through the southern part of the Field. Dinjan flows east to west. Two protected areas are located within the Field area. The north eastern part of the Khagarijan Field falls within the buffer of Dibru-Saikhowa National Park, within that a significant part falls in the core of the National Park. Apart from that the Padumoni section (1.7 sq Km) of the Bherjan-Borajan-Padumoni Wild Life Sanctuary falls in the eastern part of the Field. A large number of tea gardens are located within the Field area. Majority of the tea garden are located centrally in the Field, mostly along the southern bank of the Brahmaputra River. Major tea estate within the field area are Oakland T.G, Hazelbank T.G, Nadua T.G, North Balijan T.G, Dinjoy T.G, Kharjan T.G, Panitola T.G, Dinjan T.G, Rangagora T.G, Nalani T.G, Nokhroy T.G, Limbugudi T.G. etc. The Field mostly comprises of large tea estates, rural area with agricultural lands, settlements and homestead plantation. Tinsukia is the major town in the area, located in the south eastern most corner of the Field. Apart from that, Panitola and Chabua are two other urban areas located more or less in the southern part of the Field. Though not located within the Field, Dibrugarh town is located within 2km of the block in the south western direction. Mohanbari Airport is located in the south western part of the Field. Due to the geostrategic location of the area a large number of defense installations are located within and around the Field. Among them is the very significant air force station of north east India, Chabua Air Force base, which is located in the southern boundary of the Field. Another significant Defense installation is the Dinjan Military base, located centrally in the Field. Apart from these two major bases, a large number of large, medium and small defense installations are located in and around the block.
SENES/K-20197/ November 2013 15 Oil India Ltd. Pre Drill EIA for Drilling of 30 wells at Khagarijan Field
Photo 2.1: Nokhroy Tea Estate Photo 2.2:Agricultural lands near Chetiagaon
Photo 2.3:Brahmaputra River near Rahmoria Photo 2.4:Dinjan River
Photo 2.5: Padumoni Block of Bherjan-Borajan- Photo 2.6: AT Road near Dikom Padumoni Sanctuary
SENES/K-20197/ November 2013 16 Oil India Ltd. Pre Drill EIA for Drilling of 30 wells at Khagarijan Field
FIGURE 2-5: ENVIRONMENTAL SETTINGS OF KHAGARIJAN FIELD
SENES/K-20197/ November 2013 17 Oil India Ltd. Pre Drill EIA for Drilling of 30 wells at Khagarijan Field
2.4.2 Existing Activity in Oil Field The Khagarijan Field has overlapping areas of other exploration and production fields of OIL which is being operated for a long time. The main activities conducted by OIL at the Field are Development and Production well drilling Production of oil and gas from producing wells Transportation of oil and gas to respective Oil Compressor Station (OCS) and Gas Compressor Station (GCS) via. interconnecting pipelines
2.5 WELL LOCATIONS AND ENVIRONMENTAL SETTINGS
2.5.1 Location of Wells The proposed well sites were selected based on environmental considerations viz. location of sensitive ecological habitats, settlements, schools/ hospitals, water bodies etc. Care had been taken to locate the wells distantly from these receptors. Primarily, agricultural land and tea garden areas were selected for current drilling program. In case, well site selection in proximity to sensitive receptors could not be avoided (due to presence of geological formations), requisite clearance/permission will be obtained. Proper environmental and safety measures will be adopted to minimize footprints on these receptors. Total 30 wells are proposed in the Khagarijan Field during the plan period. Tentative well coordinates are provided in Table 2.2 and the locations of the wells at Khagarijan Field are shown in Figure 2.7.
TABLE 2-2: COORDINATES OF TENTATIVE WELL LOCATIONS Well Co-ordinate Village name/ Panchayat Dev. Block/District No Well 1 950 16/ 52.75// E, Dinjan Tea Estate Block -Chabua, District 270 33/ 29.25// N Panchayat – Dinjan - Dibrugarh Well 2 950 15/ 37.5// E, Village – Digholipathar, Block -Chabua, District 270 31/ 44.25// N Panchayat – Balijan - Dibrugarh Well 3 950 06/ 17.33// E, Village – Hathigondai , Block – Chabua, District 270 29/ 23.49// N Panchayat – Chabua - Dibrugarh Well 4 950 13/ 55.5// E, Village – Jeraipathar , Block – Chabua, District 270 31/ 06// N Panchayat – Jerai – Dibrugarh Well 5 950 04/ 8.25// E, Makalbari Tea Estate Block – Lahoal, District 270 29/ 54.75// N - Dibrugarh Well 6 950 07/ 49.04// E, Village – Orang Pati & Tiajoli, Block – Panitola, 270 28/ 58.90// N Panchayat - Nadua District - Dibrugarh Well 7 950 10/ 45.75// E, Dinjoy Tea Estate Block – Panitola, 270 30/ 18.75// N District - Dirbugarh Well 8 950 11/ 15.89// E, Dinjoy T. E Block - Panitola, 270 29/ 54.20// N Panchayat - Dinjoy District - Dirbugarh Well 9 950 12/ 51/ E, Village – Kanjikhua , Block – Panitola, 270 29/ 51.75// N Panchayat – Pulunga District - Dibrugarh
SENES/K-20197/ November 2013 18 Oil India Ltd. Pre Drill EIA for Drilling of 30 wells at Khagarijan Field
Well Co-ordinate Village name/ Panchayat Dev. Block/District No Well 10 950 14/ 00// E, Forest land Block – Panitola, 270 29/ 48.75// N District - Dibrugarh Well 11 950 07/ 42.72// E, Village – Rahmoria Block -Lahoal, District - 270 32/ 13.09// N Panchayat - Rahmoria Dibrugarh Well 12 950 09/ 00// E, Thanai Tea Estate Block – Lahoal, District 270 32/ 27// N - Dibrugarh Well 13 950 08/ 9.35// E, Village- Genichuk Block -Lahoal, District - 270 32/ 31.62// N Panchayat - Rahmoria Dibrugarh Well 14 950 09/ 59.74// E, North Balijan T. E Block – Lahoal, 270 32/ 32.67// N Panchayat - Balijan District - Dibrugarh Well 15 950 10/ 26// E, North Balijan T. E Block – Lahoal, 270 32/ 44// N Panchayat - Balijan District - Dibrugarh Well 16 950 06/ 39.75// E, Village – Nimbari, Block – Lahoal, District 270 31/ 31.5// N Panchayat – Lahoal - Dibrugarh Well 17 950 06/ 22.5// E, Village: Phukanar Khat Block – Lahoal, District 270 31/ 24// N Panchayat – Phukunar Khat - Dibrugarh Well 18 950 06/ 40.5// E, Village – Nimbari, Block – Lahoal, District 270 31/ 42// N Panchayat – Lahoal - Dibrugarh Well 19 950 09/ 39// E, North Balijan T. E Block – Lahoal, 270 32/ 38.25// N Panchayat - Balijan District - Dibrugarh Well 20 950 11/ 54// E, Kharjan Tea Estate Block – Lahoal, 270 32/ 21.75// N District Dibrugarh Well 21 950 16/ 53.70// E, Dinjan Tea Estate Block –Guijan, District 270 32/ 19.15// N – Tinsukia Well 22 950 17/ 23//E, Dinjan Tea Estate Block -Guijan, District - 270 33/ 40// N Panchayat – Dinjan Tinsukia Well 23 950 17/ 54// E, Panitola Tea Estate Block –Guijan, District 270 31/ 19.5// N – Tinsukia Well 24 950 17/ 00// E, Village – Nunpuria Jadavgaon, Block –Guijan, District 270 33/ 17.25// N Panchayat – Nunpuria – Tinsukia Well 25 950 16/ 36.57// E, Panitola Tea Estate Block -Guijan, District - 270 32/ 13.62// N Panchayat- Panitola Tinsukia Well 26 950 20/ 51.75// E, Limbugudi Tea Estate Block – Guijan, 270 32/ 20.25// N District – Tinsukia Well 27 950 20/ 15// E, Village – Jariguri, Block – Guijan, 270 30/ 51// N Panchayat – Borguri District – Tinsukia Well 28 950 18/ 19.5// E, Nalani Tea Estate Block – Guijan, District 270 33/ 17.25// N – Tinsukia Well 29 950 19/ 15// E, Village – Captain Chawk, Block – Itakhuli, District 270 28/ 37.5// N Panchayat - Laipuli – Tinsukia Well 30 950 15/ 31.5// E, Village – Panitola , Block – Itakhuli, District 270 29/ 13.5// N Panchayat – Panitola – Tinsukia
SENES/K-20197/ November 2013 19 Oil India Ltd. Pre Drill EIA for Drilling of 30 wells at Khagarijan Field
FIGURE 2-6: LOCATION OF PROPOSED WELLS ON TOPOSHEET
SENES/K-20197/ November 2013 20 Oil India Ltd. Pre Drill EIA for Drilling of 30 wells at Khagarijan Field
2.5.2 Environmental Settings As per ToR conditions, environmental setting around one km radius area (referred as study area) of each well site was carried out during field survey and the same has been checked with toposheet and satellite imagery. Well wise environmental settings are described below and well wise land use is provided in Annex 2.1. Well 1– The proposed well site is located in Tea garden plantation of Dinjan Tea estate. It falls under Dinjan Panchayat of Chabua block of Dibrugarh district. The well location can be approached by the road that starts from Assam Trunk road near Panitola town and leads to Dinjan Army camp. Majority of land use within 1km of the project site is Tea garden plantation of Dinjan tea estate. Rest of the area is used for agriculture (monocropping of paddy) and as settlement. The Dinjan tea processing factory is located about 200m west of the well location. Towards south of the well location, starts the Panitola tea estate. Settlements are present within 1km of the well location. All the human settlements are labour colony of Dinjan tea estate. The nearest settlement is located about 350m south west of the well location. Proposed location Well 22 is located 870m north east of Well 1. About 1km west of the well location starts the “Dinjan beel”, a large water body, which drains into Brahmaputra river, further north outside the study area. Well 2– The proposed well location is located on a paddy cultivation field. Dighalipathar village falls in Balijan Panchayat, of Chabua block of Dibrugarh District. On eastern as well as western side of the well location falls the settlement of Dighalipathar village, about a distance of 80m on either side. The well location can be accessed by the road that starts from Assam Trunk road near Panitola town and leads to Dinjan Army camp. The paddy cultivation field on which the proposed well location is located is actually silted bed of Mai Jan. So this paddy fields acts as major drainage system during monsoon. Majority of the land around the well location is used for Defense Installation. About 250m east as well as 250m west of the well location these defense installations are present. The second largest land use is agriculture, then comes human settlement and a very small portion of the land is used for tea garden plantation of tea estate. On the northern part falls a small portion of Udalgiri tea estate. Well 3– The proposed well is located within agricultural field of Hatigonda village of Chabua panchayat in Chabua block of Dibrugarh district. The well location can be accessed by the road that starts from Nadua Bus Stand on Assam Trunk road and travels north towards Oakland ghat. Majority of the land within 1km of the well location is used for agriculture. The agricultural fields are used for paddy cultivation, only once a year. Nearest settlement are of Hatigonda village (100m west) and Phukanar Khat village (300m north east). Within human settlement small plots of lands are used for growing household tea garden. Rest land in the study area is managed by Nadua Tea Estate for growing tea garden plantation. The study area has a slope towards south, where about 900m from well location, flows the Dinjan River. The Dinjan River flows west and drains into Brahmaputra River.
SENES/K-20197/ November 2013 21 Oil India Ltd. Pre Drill EIA for Drilling of 30 wells at Khagarijan Field
Well 4 – The proposed well is located on a household tea garden of Jeraipathar village. Jeraipathar village falls under Jerai panchayat of Chabua block in Dibrugarh district. The well location can be approached by the road that starts from Assam Trunk road near Panitola town, travels north up to Jerai and then turns west and meets Dinjoy-Balijan road. Majority of the land within 1km of the well location is used for agricultural purpose, particularly for growing paddy (once a year). Most of the agricultural field lies on the southern side of the well location. Second highest land use is of human settlement of Jeraipathar village, which lies on the western and eastern side of the well location (nearest at 150 metre north of the proposed well site). Rest of the area is used for growing tea. A very small portion is house hold tree garden, represented by small plots of land within human settlement. Majority of the tea growing area belongs to The Kharjan Tea Estate located in the north. Well 5 – The proposed well is located within tea garden plantation of Makalbari Tea Estate in Lahoal block of Dibrugarh district. The well location can be approached by the road that starts from Nadua Bus Stand on Assam Trunk road and travels north towards Oakland Ghat. Majority of the land within 1km of the well location is used for tea garden plantation of Makalbari tea estate. An electricity department substation is located about 100m north east of the well location. The nearest human habitation is Notun line labour colony of Makalbari tea estate, which is located about 250m north of the well location. Second highest land use is agriculture of paddy, which is almost entirely practiced on silted bed of Mai Jan passing more or less through the centre of the study area, in a north east to south west direction. General slope of the land is towards the paddy fields of Mai Jan, and water generally flows towards south west in this particular part of the Mai Jan system. Well 6 – The proposed well location is located in the agricultural land within Ahamedi Tea Estate in Nadua panchayat of Panitola block in Dibrugarh district. The proposed well location can be approached from Assam Trunk road, by a 900m mud road through tea garden plantation of Ahamedi tea estate. Majority of the land within 1km of the Well is used for cultivation of paddy, only during the monsoon. Nearest habitation is of Orang pati labour colony (100m North) of Ahamedi tea estate. The second largest land use within the study area is Tea garden plantation of Ahamedi tea estate. About 750m north east of the proposed well location a defense installation is present. Proposed well location is situated about 300m south of east to west flowing Dinjan. Dinjan l is the major drainage system in the study area. The defense installations are present within 1km of the proposed well location. One installation is present in the southern end of the study area and the other is located in the northern part of the study area. Well 7 – The proposed well location is located in tea garden plantation of Dinjoy Tea Estate in Panitola block of Dibrugarh district. The proposed well location can be approached from Dinjoy-Balijan road via a broad under construction earthen road. Majority of the land within 1km of the well location is used as tea garden plantation, which is maintained by Dinjoy tea Estate. Second highest land use of the study area is agriculture (monocropping of Paddy). Majority of the paddy field is located in the eastern side of the study area. Nearest settlement is Dinjoy Gaon (250m North-East) and Labour colony of Dinjoy tea estate (500m south
SENES/K-20197/ November 2013 22 Oil India Ltd. Pre Drill EIA for Drilling of 30 wells at Khagarijan Field west). Ongoing OILs exploratory activity is taking place within 600m south east of proposed well location 7, along Dinjoy-Balijan road. The study area has a slope towards North-West direction, through where Dinjan flows. The stream flows west and drains into Brahmaputra. Well 8 – The proposed well location is located in tea garden plantation of Dinjoy Tea Estate in Panitola block of Dibrugarh district. The proposed well location can be approached from Dinjoy-Balijan road. Dinjoy-Balijan road originates from Assam Trunk road. Assam Trunk road passes about 700m south of the proposed well location. Majority of the land within 1km of the well location is used as tea garden plantation, which is maintained by Dinjoy tea Estate. Paddy field is not present within the study area. Nearest settlement is Balijan Pani Era (100m east). A large defense installation is present about 200m east and south east of the proposed well location. About 500m north of the proposed location, an already functioning exploratory well of OIL is present. Well 9– The proposed well location is located in agricultural field of Kanjikhua village of Pulunga panchayat in Panitola block of Dibrugarh district. The proposed well location can be accessed by Assam Trunk road, which passes through 200m north of the well location. Majority of the land within 1km of the proposed well location is used for monocropping of paddy. Most of the land in the southern side of the study area is under paddy cultivation. Tea garden plantation of Kanjikhua Tea estate occupies the northern part of the study area. Settlements are mainly located around the Assam Trunk road. Nearest settlement is Kanjikhua village (150m north). In general the study area is sloped towards south. Well 10 – The proposed well location is located in a patch of degraded forest of forest department land in Panitola block of Dibrugarh district. The site can be accessed from Assam Trunk road, which passes through 20m south of the proposed well location. A small patch of degraded forest is present in the centre of the study area. Majority of the land within 1km of the proposed well location is under tea garden plantation. On the northern side of the Assam trunk road the tea garden plantation is managed by Panitola Tea Estate, and on the southern side of the Assam trunk road the tea garden plantation is managed by Kanjikhua tea estate. Nearest settlement is Matimekhana village (300m north). Agricultural field of paddy are located on the extreme northern and southern side of the study area. Monoculture of paddy is practiced in this region. Well 11 – The proposed well location is located in an agricultural field of Rahmoria village of Rahmoria panchayat in Lahoal block of Dibrugarh district. The well location can be accessed by the road that starts from Assam Trunk road near Hatiali town and leads to Rahmoria in the north. Majority of the land within 1kmof the well location is under agriculture. Mostly monoculture of paddy is practiced only during the monsoon season. Rest of the area in the study area is used for settlement. The nearest settlement is Rahmoria village (100m south). There is no tea estate within 1km of the proposed well location. Proposed location well 13 is situated 900m north east of proposed location Well 11. The study area is gently sloped towards north, where Brahmaputra river flows about 1.3km from proposed well location.
SENES/K-20197/ November 2013 23 Oil India Ltd. Pre Drill EIA for Drilling of 30 wells at Khagarijan Field
Well 12 – Proposed location is located on tea garden plantation of Thanai tea estate. It falls under Lahoal block of Dibrugarh district. The well location can be approached by the road that starts from Assam Trunk road near Hatiali town to Rahmoria. More than half of the land within 1km of the well is used for Tea garden plantation. On the northern side of the well lies the Balijan North Tea Estate. And on the southern side lies Thanai tea estate. Rest of the land is used for human habitation and paddy field. About 800m west of the well location lies Genichuk village. OILs production well is located in North Balijan Tea estate, about 750m north east of the proposed location. A narrow stream flowing north into Brahmaputra River is situated about 40m north east of the proposed well location. Well 13 – The proposed well location is located in an agricultural field of Rahmoria village of Rahmoria panchayat in Lahoal block of Dibrugarh district. The well location can be accessed by the road that starts from Assam Trunk road near Hatiali town and leads to Rahmoria in the north. Majority of the land within 1kmof the well location is under agriculture. Mostly monoculture of paddy is practiced only during the monsoon season. Rest of the area in the study area is used for settlement. The nearest settlement is Genichuk village (100m south). Thanai tea estate is located in the south eastern side of the study area. The study area is gently sloped towards north, where Brahmaputra River flows about 1.3km from proposed well location. Well 14 – The proposed well location is located within tea garden plantation of North Balijan tea estate of Lahoal block in Dibrugarh district. The proposed well location can be approached through Dinjoy-Balijan road, arising from Assam Trunk road. Majority of the land within 1km of the proposed well location is within tea garden plantation of Balijan North tea estate. Balijan North tea estate factory is located 60m west of the proposed well location. The nearest settlement is labour colony of Balijan North tea estate (100m north). No other agricultural activity is present within the study area. Buffer boundary of Dibru- Saikhowa National Park starts about 800m north of the proposed well location. Proposed location Well 15 and Well 19 is situated 800m north east and 500m north-west of well 14 respectively. The area is mainly drained through the drainage channels of the tea garden plantation. This drains ultimately leads into the Brahmaputra River flowing through the north of the study area. Well 15 – The proposed well location is located within tea garden plantation of North Balijan tea estate of Lahoal block in Dibrugarh district. The proposed well location can be approached through Dinjoy-Balijan road, arising from Assam Trunk road. Majority of the land within 1km of the proposed well location is within tea garden plantation of Balijan North tea estate. The nearest settlement is labour colony of Balijan North tea estate (250m east). No other agricultural activity is present within the study area. Buffer boundary of Dibru-Saikhowa National Park starts about 560m north of the proposed well location. Another proposed location Well 14 is situated about 800m south west of proposed location Well 15. The area is mainly drained through the drainage channels of the tea garden plantation. This drains ultimately leads into the Brahmaputra River flowing through the north of the study area.
SENES/K-20197/ November 2013 24 Oil India Ltd. Pre Drill EIA for Drilling of 30 wells at Khagarijan Field
Well 16 – The proposed well location is located in household tea garden of Nimbari village. Nimbari village is in Lahoal panchayat of Lahoal block in Dibrugarh district. The well location can be accessed by the road that starts from Assam Trunk road near Hatiali town and leads to Rahmoria in the north. The area within 1km of the proposed well location is a mosaic of agricultural field, household tea garden, tea garden plantation and settlement. Household tea garden is located in the central part of the study area. Western part is mainly dominated by agricultural field, where monoculture of paddy is done (during monsoon). Settlements mainly dominate the northern part. Nimbari village is located about 350m north of proposed well site. Nearest settlement is labour colony of Thanai tea estate (150m south). Two other proposed well location Well 17(500m west) and Well 18(350m north) are present within the study area. Towards the eastern and southern part of the study area lies tea garden plantation of Thanai tea estate. Well 17 – The proposed well location is located in agricultural field of Phukanar Khat village. Phukanar Khat village is in Lahoal panchayat of Lahoal block in Dibrugarh district. The well location can be accessed by the road that starts from Assam Trunk road near Hatiali town and leads to Rahmoria in the north. Majority of the land within 1km of the proposed well is under agriculture, mostly monocropping of paddy during monsoon. Paddy field mostly stretches in the north and western part of the study area. Nearest settlement is Phukanar Khat village (150m south). On the eastern part of the project area lies a small stretch of household teagarden. The southern side of the study area is dominated by tea garden plantation of Thanai Tea Estate. Two other proposed well location Well 16(500m east) and Well 18(750m north east) are present within the study area. Well 18 – The proposed well location is located in agricultural field of Nimbari village. Nimbari village is in Lahoal panchayat of Lahoal block in Dibrugarh district. The well location can be accessed by the road that starts from Assam Trunk road near Hatiali town and leads to Rahmoria in the north. The area within 1km of the proposed well location is a mosaic of agricultural field, household tea garden, tea garden plantation and settlement. Western and northern part is mainly dominated by agricultural field, where monoculture of paddy is done (during monsoon). Nearest settlement is Nimbari village (80m north). Household tea gardens of Nimbari village are present on the eastern part of the study area and towards south tea garden plantation of Thanai Tea Estate is located. Two other proposed well location Well 16(350m south) and Well 17(750m south west) are present within the study area. Towards the eastern and southern part of the study area lies tea garden plantation of Thanai tea estate. Well 19 – The proposed well location is located within tea garden plantation of North Balijan tea estate of Lahoal block in Dibrugarh district. The proposed well location can be accessed through Dinjoy-Balijan road, arising from Assam Trunk road. Majority of the land within 1km of the proposed well location is within tea garden plantation of Balijan North tea estate. Balijan North tea estate factory is located 380m east of the proposed well location. The nearest settlement is labour colony of Balijan North tea estate (500m east). No other agricultural activity is present within the study area. The area is mainly drained through the drainage channels of the tea garden plantation. This drains ultimately leads into the
SENES/K-20197/ November 2013 25 Oil India Ltd. Pre Drill EIA for Drilling of 30 wells at Khagarijan Field
Brahmaputra River flowing through the north of the study area. One production well of Oil India Limited is located 370m west of the proposed well location, inside Balijan North Tea Estate. Proposed location Well 14 is situated 500m south east of the proposed location Well 19. Buffer boundary of Dibru-Saikhowa National Park starts about 700m north of the proposed well location. Well 20– The proposed well location is located within tea garden plantation of Kharjan tea estate of Lahoal block in Dibrugarh district. The proposed well location can be accessed through Dinjoy-Balijan road, arising from Assam Trunk road. Majority of the land within 1km of the proposed well location is within tea garden plantation of Kharjan estate, only a small portion in the southern part is located within the Balijan tea estate. The nearest settlement is labour colony of Balijan North tea estate (500m east). No other agricultural activity is present within the study area. The area is mainly drained through the drainage channels of the tea garden plantation. Nearest settlement is Raiding village (550m west). The study area has a slope towards west, where there is low land (600m west), that turns into seasonal marshland during monsoon. Another slope is towards south, towards paddy fields on the silted Mai Jan. Well 21 – The proposed well location is located within tea garden plantation of Dinjan tea estate. It is located in Guijan block of Tinsukia district. The proposed well can be approached by earthen road inside the Dinjan tea estate. Majority of the land is used as tea garden plantation. In the northern side the tea garden plantation is managed by Panitola tea estate, and in south tea garden is managed by Dinjan tea estate. Nearest settlement to the well is Dinjan TE colony located at 350 m south west. On the western side of the study area a huge defense installation is located (600m). Another proposed location Well 25 is situated about 500m south west of Well 21. Silted Mai Jan (120m west) acts as the main drainage system in the study area. It drains into “Dinjan beel”, a large water body (2.5km north). Monoculture of paddy is practiced in the silted bed of Mai Jan. Well 22 – The proposed well location is located within tea garden plantation of Dinjan tea estate. It is located in Guijan block of Tinsukia district. The well location can be accessed by the road that starts from Assam Trunk road near Panitola town and leads to Dinjan Army camp. Majority of the land within one km of the proposed well location is used for tea garden plantation by Dinjan tea estate. Nearest settlement is labour colony of Dinjan tea estate (200m west). Proposed location Well 1 is located 870m south west of Well 22. Cluster of agricultural fields are located in the southern side of the study area. Paddy is cultivated (one a year, during monsoon) in these agricultural fields. A large water body “Dinjan Beel II” (500 m) dominates the north eastern part of the study area. It ultimately drains in Brahmaputra River to the north of the study area. So this water body acts as a major drainage system in the study area. Well 23 – The proposed well location is located within paddy cultivation land of labour colony of Panitola tea estate. It is located in Guijan block of Tinsukia district. The proposed well can be approached by earthen road inside the Panitola tea estate. Paddy fields are located
SENES/K-20197/ November 2013 26 Oil India Ltd. Pre Drill EIA for Drilling of 30 wells at Khagarijan Field in the Silted Mai Jan, which also acts as the main drainage system in the study area, accumulated water in monsoon flows north through it. Monoculture of paddy is practiced in this area. Majority of the land within 1km of the proposed well location is used as tea garden plantation. In the eastern side of study area, the tea garden plantation is managed by Panitola tea estate, and in west tea garden is managed by Nokhroy tea estate. Nearest settlement is labour colony of Panitola tea estate (100m west). About 600m east of the proposed well location, tea processing factory of Nokhroy Tea estate is situated. Well 24 – The proposed well location is located on a paddy cultivation field of Nunpuria Jadav Gaon village. It is located in Nunpuria panchayat, within Guijan block of Tinsukia district. The proposed well location can be approached by a earthen road that starts from Assam Trunk road near Nunpuria Notun gaon and leads north towards Nunpuria Jadav gaon. Majority of the land within 1km of the proposed well location is used for mono culture of paddy during monsoon. Nearest settlement is Nunpuria Jadav Gaon (300m west). A small portion of land in north east and south west part of study area is under tea garden plantation of Panitola tea estate. Well 25 – The proposed well location is located within tea garden plantation of Panitola tea estate. It is located in Guijan block of Tinsukia district. The proposed well can be approached by earthen road inside the Panitola tea estate. Majority of the land in the study area is used as tea garden plantation. In the northern side of study area, the tea garden plantation is managed by Panitola tea estate, and in south tea garden is managed by Dinjan tea estate. On the western side of the study area a huge defense installation is located (90m from well location). Nearest settlement to the well is Dinjan TE colony located at 340 m south east. Another proposed location Well 21 is situated about 500m north east of Well 25. Silted Mai Jan (60m east) acts as the main drainage system in the study area. It drains into “Dinjan beel”, a large water body (2.5km north). Monoculture of paddy is practiced in the silted bed of Mai Jan. Well 26– The proposed well location is located within tea garden plantation of Limbugudi tea estate. It is located in Guijan block of Tinsukia district. The proposed well location can be accessed by earthen road inside Limbugudi tea estate. Tea garden plantation in the central and north western part of the study area is managed by Limbugudi tea estate, western part is managed by Rongagora Tea estate and in the southern and eastern part the tea garden Plantation belongs to Gelapukhuri Tea estate. The nearest settlement is labour colony of Limbugudi Tea estate (100m north). Small patches of agricultural fields are present within settlement. Mainly mono culture of paddy is practiced in the agricultural fields. Well 27 – the proposed well location is located within agricultural field of Jariguri village. Jariguri village falls in Borguri panchayat in Guijan block of Tinsukia district. The well location can be approached through Gelapukhri – Borguri road. Majority of the area within one km of the proposed well location is under habitation. Nearest habitation is Jariguri village (80m east of well location). Large stretch of agricultural field is present between Jariguri village and Lezeihoola village. In the northern part of the study area tea garden plantation of
SENES/K-20197/ November 2013 27 Oil India Ltd. Pre Drill EIA for Drilling of 30 wells at Khagarijan Field
Bozaltoli tea estate is located. About 300m east of the well location a defense installation is present. And about 500m north east of the proposed well location Tinsukia Prison is located. Well 28 – The proposed well location is located within tea garden plantation of Nalani tea estate. It is located in Guijan block of Tinsukia district. The proposed well location can be accessed by tar road inside Nalani tea estate. Majority of the land within one km of the proposed well location falls within the tea garden plantation of Nalani tea estate. Nearest habitation is labour colony of Nalani Tea estate (200m south west). Agricultural fields are present in the vicinity of the settlement. Mostly monoculture of paddy is done during the monsoon. “Dinjan beel 2” is located in north eastern part of the study area, about 450m from the proposed well location. Well 29– The proposed well location is located in Captain Chawk village of Laipuli panchayat, within Itakhuli block of Tinsukia District. The proposed well location can be approached from Assam Trunk road, which is situated 30m north from the well location. Assam Trunk road is important feature within the study area. It runs diagonally in an east west orientation through the centre of the study area. Inside the study area habitation is clustered all along the length of the Assam trunk road. The proposed well site is located adjacent to an industrial establishment. Nearest habitation is Captain Chawk village (90 m east). Few industrial sheds are located at west and north of the well site beyond NH-37 and railway line. Urban settlement of Tinsukia starts about 300m east of the proposed well. New Tinsukia Railway Junction is located 1km east of the proposed well location. In the north western as well as south western part of the study area large stretches of agricultural fields are present. Mostly monoculture of paddy is practiced in these fields during monsoon season. Well 30 – The proposed well location is located in agricultural field of Panitola village. Panitola village is in Panitola panchayat within Itakhuli block of Tinsukia district. The proposed well location can be accessed from Panitola-Baruatola PWD road. The well location is inside a large span of agricultural field surrounded by habitation on all sides. The habitation is located within 200m (in south west) to 500m (in east) of the well location. Eastern, southern and western side of the well is surrounded by Panitola village, and to the north Panitola town is located. Assam trunk road runs through the northern part of the study area, through the Panitola town. A small part of tea garden plantation of Panitola Tea estate falls in the northern part of the study area. The area has a gradual slope towards south.
2.6 PROJECT ACTIVITIES AND SCHEDULE
The lifecycle of project activities for the proposed project has been divided into distinct steps and each is described in detail in the subsequent sections and will take approximately three months to complete drilling and testing activity at each well site. The project lifecycle has been classified into three phases:
Pre-drilling activity Site selection
SENES/K-20197/ November 2013 28 Oil India Ltd. Pre Drill EIA for Drilling of 30 wells at Khagarijan Field
Land acquisition Site access road and drill site construction Pre-drilling activities, mobilization and Rigging up Initial well construction
Drilling activity Drilling of wells Testing of wells
Well decommissioning Well abandonment Site closure and decommissioning Site Restoration
2.6.1 Pre-drilling Activity The pre-drilling phase will involve the following activities:
Site Selection All the locations selected by OIL’s were based on geological data available. Suitable drilling locations were selected based on the physical (terrain and access) and technical suitability. Detailed drill site and access road survey will be carried prior to land procurement and construction of drill site. Selecting drill site’s environmental considerations is as below: Non-forest area and area with low vegetation. Away from organized human habitats. Easy access to area of interest Away from sensitive ecological habitat and migratory route
Land Acquisition During the site selection process all the legal requirements will be considered and surface location finalized. Once the surface drilling location is finalized, land acquisition will be done including crop compensation. After finalization of drill site, OIL will procure the land from the land owners. The estimated land required per drill site is approximately 2.2 ha. Tentative well coordinates provided by OIL revealed 15 wells within plantation areas of tea garden 12 wells are located in agriculture land, 2 wells located in household tea garden areas and 1 well within forest land. All the proposed drill sites are away from human habitation; therefore any displacement will not be required for this project. As displacement is not required, resettlement and rehabilitation is not applicable for this project.
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Private Land Generally, OIL will procure the required land through private negotiation. In few cases, OIL may apply the provision of Rule-189/190 of AL&RR, 1886, if private negotiation is not successful. During purchase of private land OIL will compensate the land owners for its land value and standing crop. Rehabilitation and Resettlement: All proposed drill sites are located away from human habitation. Therefore, any rehabilitation and resettlement will not be required for the project. Additionally, it is to be mentioned that, no rehabilitation and resettlement is required during construction or strengthening or widening of approach road to reach to drill site.
Access Road and Site Construction Construction of Access Road All the tentative wells are located adjacent to the existing road; the distance of the proposed well pad will be of 200 m (maximum) from existing road. Construction of site access road will not require any forest land or involve displacement of any household. As far as possible, existing roads will be used. Cutting of trees will be avoided. If necessary, existing road will be developed by widening, etc. Culverts and drainage channel will be maintained during site preparation. The approach road will be constructed by a contractors appointed by OIL. Drill Site Construction The ground is relatively flat in the Khagarijan Field. Vegetation varies from place to place. Wells located on the agricultural land have no vegetation; whereas, wells located in the tea garden have tea bushes with shade trees. Site construction work will require clearing of tea bushes and some trees in the drill sites located in the tea garden. After clearance of vegetation, top soil of the entire drill site will be scraped and stored in the top soil storage area for future use. Once the top soil removal process is completed, leveling and compaction will be done with help of graders and mechanical rollers. Drill sites may require filling of earth to elevate the drilling platform based on local topography and High Flood Level (HFL). Quantity of fill material required for each drill sites depends upon the site elevation and HFL. Fill material will be met from excavated material for pit required for drill site and balance amount will be sourced from authorized quarry area. An area of 2.2 ha (approximate) will be required for each drill site to facilitate drilling and testing activity. Reinforced Cement Concrete (RCC) will be used for the construction of foundation system. For making foundations of the main rig structure, cast in-situ bored under- reamed piles of specified lengths will also be used. For the construction of a drill site, a total of about 2500 kg of cement, 5000 kg of sand, 500m3 of earth/fill material, 200 kg steel and 1000m3 of aggregate will be required. A backhoe will be used for all excavation and cutting activities (for construction of pits) on site. Subsequently, the proposed well site &
SENES/K-20197/ November 2013 30 Oil India Ltd. Pre Drill EIA for Drilling of 30 wells at Khagarijan Field campsite will be duly fenced to a height of about 2 m using jingle wired fencing or expm fencing. Site preparation will also involve the following: Construction of cellar pit 1.85m X 2.15m X 1.5 m for installation of well head and BOP Construction of HDPE lined pit of ~800m3 at well site for temporary storage and disposal of drill cutting Construction of HDPE lined pit of 3030 m3 for temporary storage and disposal of drilling wash water & waste mud (800 m3) and rain water (2230 m3) Septic tanks and soak pits to dispose the domestic wastewater at the drill site.
The transport of rig including ancillary equipments and camp facilities to the site is expected to comprise around 100 trailer loads. Though the rig and related equipments will be directly brought to site, spares, chemicals and other materials will be received from the warehouse located at Duliajan. Materials will be intermittently supplied from warehouse to the drilling site, during operations; a provision will be kept for temporary storage of materials at the drilling site itself.
Rig Mobilization and Rigging up A rig building process will follow the site preparation activities. This process involves transport of rig including auxiliary equipments and camp facilities, assembling of various rig parts and equipment to drill a well. The rig including auxiliary equipments and camp facilities will comprise of around 100 truck/trailer loads. Once the drilling rig is assembled, thorough rig inspection will be carried out to check equipment working capability and quality standards. The rig will have various allied equipments like mud tanks, mud pumps, compressors, fuel tank, DG sets etc.
Initial Well Construction Spudding-in well is the start of drilling activity. Top-hole section will be drilled to a desired depth based on well design. After drilling top-hole section, it will be cased with a pipe called “Casing”. Casing provides support to hole wall and secures hole section. Other than that, it isolates problematic hole sections such as loss zones, shale sections, over pressurized formations, etc. After running casing, space between hole wall and “Casing” will be cemented. This process of drilling and casing the hole section continues until the final well depth (target) is achieved. Lengths and diameters of each section of the well are determined prior to drilling and are dependent on the geological conditions through which the well is to be drilled. Once each section of the well is completed, the drill string is lifted and protective steel pipe or casing lowered into the well and cemented into place. Proposed well profile and casing plan is given in shown in Figure 2.7.
SENES/K-20197/ November 2013 31 Oil India Ltd. Pre Drill EIA for Drilling of 30 wells at Khagarijan Field
2.6.2 Drilling Activity The exploitation of hydrocarbons requires the construction of a conduit between the surface and the reservoir. This is achieved by the drilling process. The exploration and development wells will be drilled using a standard land rig or a “Mobile Land Rig” with standard water based drilling fluid treatment system. This rig will be suitable for deep drilling up to the desired depth of 4500 metres as planned for the project. The typical configuration of a Drilling Rig is shown in the Figure 2.8.
FIGURE 2-7: TYPICAL DRILLING RIG CONFIGURATION Additionally, there will be other ancillary facilities like Drilling mud system, ETP, Cuttings disposal, Drill Cementing, equipment etc. and utilities to supply Power (DG sets), water, fuel (HSD) to the drilling process and will be set up as a part of the project. Mud System and Cuttings During drilling operations a fluid known as drilling fluid (or ‘mud’) is pumped through the drill string down to the drilling bit and returns between the drill pipe –casing annulus up to surface back into the circulation system after separation of drill cuttings /solids through solids
SENES/K-20197/ November 2013 32 Oil India Ltd. Pre Drill EIA for Drilling of 30 wells at Khagarijan Field control equipment. Drilling fluid is essential to the operation and helps in controlling downhole pressure, lift soil/rock cuttings to the mud pit, prevent cuttings from settling in the drill pipe, lubricate, cool and clean the drill bit amongst other functions. It has been decided that a uniform water-based mud system will be used in all the proposed wells. Unlike an oil-based mud system, usage of water-based mud will not pose higher risk of contamination to subsurface formations, but disposal of the fluid and cuttings will be less problematic. Because of the anticipated borehole instability problems it may be necessary to introduce a base salt, such as Potassium Sulphate (K2SO4) into the system. Tentative mud program for a well is given in Annex 2.2. The hole section-wise use of chemicals is presented in Annex 2.3. Mud used during the operation will flush out formation cuttings from the well hole. These cuttings will be separated from the drilling mud using a solids-control and waste management package. Cuttings will then be stored in the HDPE lined pits (of approximately 800 m3 capacity) and after completion of the drilling activities, cuttings will be tested for hazardous nature and based on nature of the drill cuttings, final disposal pathway will be finalized by OIL. The total amount of cuttings produced during the entire drilling period is projected to be about 290 m3. Once the cuttings have been separated, the drilling fluid will be reused or processed after further treatment in a Chemically Enhanced Dewatering (CED) system designed to remove suspended solids that are too fine for mechanical separation in solids control package producing inlet particles called ‘flocs’. The flocs will be removed in the decanting centrifuges and the resultant sludge disposed off in High Density Polyethylene (HDPE) lined pits (of approximately 800 m3 area). The cleaned waste water will also be stored in HDPE lined pits and disposed off, after testing and any necessary treatment, to meet the regulatory requirements. The whole process by which the drilling fluid will be reused during the drilling operation is commonly known as a “closed loop system.” This system is ideal for drilling operations in sensitive environments as it cuts down immensely on the total water consumption for the formulation of drilling mud and also saves on the consumption of chemicals. Figure 2.9 shows the schematic layout of the drilling waste management. Figure 2.10 shows the drilling fluid circulation system which is designed to enable the drilling fluid to be recycled and maintained in good condition throughout the operation. Various components of the drilling mud will be selected carefully to be able to provide desired properties to the mud. Mud chemicals will be added to the uniform mud system to adjust the mud properties and ensure fluid loss control/circulation, lubricity, shale inhibition, pH control and pressure control in the well during drilling. Chemicals required for the preparation of drilling fluid will be centrally stored in Duliajan. Additionally, some chemicals will also be stored in the drill site. The storage area will be paved and bunded and will be provided with a shed. The list of chemicals to be used during drilling is presented in Annex 2.3
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FIGURE 2-8: DRILLING WASTE MANAGEMENT
Drilling Operation Drill cuttings plus Drilling mud separation drilling mud in shale shaker
Drilling mud reused
Washed & free of oil drill Disposal after testing and cuttings to HDPE lined drill treatment to meet regulatory cutting pit requirement Drill cutting washing
Disposal after testing and Washed waste water to HDPE treatment to meet regulatory lined waste water pit requirement
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FIGURE 2-9: TYPICAL DRILLING FLUID CIRCULATION SYSTEM
Cementing Programme Cementing is a necessary aspect of drilling oil and gas wells. Cement is used to Secure/support casing strings Isolate zones for production purposes Solve various hole problems
Cementing generally utilizes Portland cement (API Class G Oil Well Cement) with various additives in small quantities as accelerators/retarders, density adjusters, dispersants, fluid loss additives, anti gas migration additives, etc.
Well Logging Between the drilling operations for different zones, logging operations are undertaken to provide information on the potential type and quantities of hydrocarbons present in the target formations. Technicians employed by a specialist Logging Service will be entrusted with the job of undertaking well logging. Logging instruments (sensors) will be attached to the bottom of a wire line and lowered to the bottom of the well. They are then slowly brought back, the devices reading different data as they pass each formation and recording it on graphs, which can be interpreted by the geologist, geophysicist and drilling engineer. There are no emissions to the environment associated with wire line logging operations. The radioactive source required for well logging operations will be kept in specially designed container.
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Hydrocarbons in the form of oil and/or gas are flowed during well testing operations. The excess hydrocarbon will flared.
2.6.3 Well Decommissioning
Well Abandonment On completion of activities, wells will be either plugged and suspended (if the well evaluations indicate commercial quantities of hydrocarbons) or killed and permanently abandoned (in the event of absence of resources). In the event of a decision to suspend the well, it will be filled with a brine solution containing very small quantities of inhibitors to protect the well. The well will be sealed with cement plugs and wellhead fittings (Blind Flange) left on the surface (Cellar). If the well is abandoned, it will be sealed with a series of cement plugs, all the wellhead equipment will be removed leaving the surface clear of any debris and site will be restored.
Site Closure and Decommissioning After completion of the drilling activity, partial de-mobilisation of the drilling rig and associated infrastructure will be initiated. As discussed earlier, well testing may be carried out immediately after the drilling is completed or about 3 months depending on initial evaluation timing. The complete de-mobilisation of the facilities at site will happen after well-testing has been completed. This will involve the dismantling of the rig, all associated equipments and the residential camp, and transporting it out of the project area. It is expected that demobilization phase will last about 10 days and will involve the trucking away of materials, equipments and other materials from site to bring it back to original condition. It is estimated that about 100 truckloads will be transported out of site during this period. Subsequently, following steps will be typically involved to restore and rehabilitate the area: The wellhead and all casing string will be cut off to a minimum depth of 3 m (10 ft) below ground level. All concrete structures will be broken up, and the debris disposed off All other waste products, solid and liquid, will be disposed of in accordance with the requirements of the EIA and will be treated to render them harmless. All fencing and access gates will be removed. All pits whose contents will show regulatory compliance for on-site disposal, at the time of site closure, will be backfilled and closed out as per the legal requirements. Restoration of unusable portion of the access track, removal of pilings and Landscaping.
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Site Restoration All abandoned drill sites will be restored back to its near original condition. After decommissioning of site, it will be de-compacted and stored top soil will be overlain on the de-compacted site with certain moisture conservation measures and seeding of leguminous plant for restoration soil nutrient level naturally.
2.7 UTILITIES & RESOURCE REQUIREMENTS
2.7.1 Power Supply The power requirements at the site preparation and construction phase for the drill site will be met by 125 KVA DG Sets. Although drilling operations will be continuous, power requirement will vary depending on activities being carried out. It is anticipated that two DG sets with a power rating of 1000 KW each will be required for drilling purposes of which one will be kept standby. Lighting and other power requirements at drill sites will be met through 200 KW DG sets.
2.7.2 Water Consumption and Supply Total water requirement for the drill site preparation and construction phase of the project is estimated to be about 10 KL. With average time requirement for site preparation being approximately 20 days, about 0.5 KLD of water will be consumed daily, on an average. The total projected average consumption of water during the drilling phase will be about 40 KLD per well including domestic purposes. Water will be sourced through bore well; OIL will take permission for Ground Water Authority regarding abstraction of ground water for industrial purposes if required. The water requirement per well is shown in Table 2.3.
TABLE 2-3: WATER REQUIREMENT PER WELL
Description Quantity Total Water Requirement for Drilling (KL) 3600 No. of Days on well 90 Average drilling water consumption per day (KLD) 30 Average water for domestic use/day (KLD) 10 Total water consumption/day (KLD) 40
A provision for storage of about 200 KL of water (5 days water requirement during peak period) will be made on site. Potable water requirement at site will be met through filtered bore well water and some packaged drinking water. In addition, a water storage pit of around 1000 KL is proposed to store water for fire water supply the likely source being ground water. The water balance diagram is provided at Figure 2.11
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FIGURE 2-10: WATER BALANCE DIAGRAM
Water sourced from onsite borewell
(40m3/day)
/d
/d 3
3
/d
3
/d
3
10m
5m
20m 5m Rig wash Mud Sanitation Kitchen & Laundry
Preparation
/d) /d)
3 3
Mast Shale Mud tank Cement (4m
Shaker Vessels (4m
cleaning
/d
/d /d
3
/d
3 3
3
2m 2m
2m
0.2m
Septic Tank & Soak Pit
Treated at ETP to conform with CPCB discharge standards
Discharge to Local Drainage Channel
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2.7.3 Fuel Consumption Fuel consumed during the drilling phase will mainly be diesel used for various equipments and vehicles operating to transport goods and supplies to site. It is estimated that about 1 KL diesel will be required to power the off-road construction equipment and vehicles during site preparation phase. During the drilling phase, consumption about 3.5 KLD of High Speed Diesel will be required. Fuel will be supplied onsite by local supplier through mobile tankers. Out of this, a major part comprising about 85% will be consumed by the rig (also include the DG sets) and about 15% will be required for the campsite.
2.7.4 Accommodation and Campsites Sometimes it is necessary to provide camp facilities to operations staff, crew and other contractor personnel. The campsite will provide accommodation to all operational crew and the contractor personnel. At any point of time, it is anticipated that about 50 personnel per shift will be housed in the campsite during the well drilling campaign. Toilet facilities will be built in as part of the accommodation unit. The sewage lines from units will be connected through a pipeline system to a septic tank and soak pit system constructed as per requirements of local laws. Food and other organic waste will be subjected to bio-degradation through organic composting.
2.7.5 Manpower / Employment During the drilling phase, about 50 people will be working per shift. This will include technical experts (including expats), who will be responsible for various drilling related activities and some local workmen who will be hired from nearby villages for the entire duration of the project. Technical staff will be housed whenever required in the Drilling Camp Site which will be adequately supported by facilities like kitchen, wash rooms, laundry, etc.
2.8 POLLUTION SOURCES AND CHARACTERIZATION
2.8.1 Noise and Vibrations Noise will be emitted from drill site during site preparation, drilling and decommissioning phases. The major noise generating operations from the proposed activity during drilling, testing are operation of rotary drilling equipment as part of rig, diesel engines for power generation, mud pumps and operation of vehicles. Noise during the site preparatory phase will primarily be contributed by heavy construction machinery operating on site and vehicular sources. Average noise emission ranges for different types of construction machinery and noise level of drilling rig and its equipment are shown in Table 2.4 and Table 2.5 respectively.
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As drilling activity is continuous, part of the noise associated with functioning of the rig and ancillaries will be generated throughout day and night.
TABLE 2-4: TYPICAL NOISE EMISSIONS FROM CONSTRUCTION MACHINERY
Sound Level At Operator (in decibels) Equipment Average Range Earth Moving Equipment Front End Loader 88.0 85-91 Back Hoe 86.5 79-89 Bull Dozer 96.0 89-103 Roller 90.0 79-93 Truck 96.0 89-103 Material Handling Equipment Concrete Mixer <85.0 - Crane/Hydra <85.0 - Derrick 100 97-102 Source: British Columbia, “Construction Noise,” Workers Compensation Board of BC
TABLE 2-5: DRILLING RIG AND EQUIPMENT NOISE LEVEL
Equivalent noise levels in dB(A) Equipment Average Range Drilling Rig 96.9 88.0-103.0 Mud Pumps 76.9 73.3 -80.5 Diesel Generators 72.7 71.8-73.7 Shale Shakers 76.6 -
2.8.2 Air Emissions Air emissions from point sources expected from the proposed drilling activity will be mainly from combustion of diesel in the diesel engines and power generators which will be operated to meet power requirement of the drilling rig and the campsite. The principal pollutants will comprise of Suspended Particulate Matter (SPM), Sulphur and Nitrogen dioxides (SO2 and
NO2) and other hydrocarbons (HC). The quantity of diesel consumed during drilling will be in order of 3.5 KL /day/drilling site. Additionally, the flaring and burning of oil during the testing of the well will also lead to the release of some pollutants including un-burnt hydrocarbons to the atmosphere. Some fugitive emissions of dust and air pollutants from vehicular exhaust will also happen during the project lifecycle, mostly during the construction and decommissioning activities.
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Additionally, there will be re-entrainment of dust from the approach road leading to the site mainly during the dry season. Analysis of natural gas generated from the well site reveals that, it is mostly methane, ethane and propane without the presence of hydrogen sulfide (Annex 2.4).
2.8.3 Liquid wastes During the drilling operations, drilling wastewater generated (approximately 6.2 m3 per day) as a result of rig wash and dewatering of spent mud, effluents from washing of drill cuttings, floor washings, pump, seal leakages, spillages will comprise of chemical ingredients of drilling fluid thereby rendering effluent to be polluted. The characteristics of drilling and wash wastewater will be primarily dependent on type and composition of drilling fluid used for drilling. As OIL is proposing the use of water-based drilling mud, the potential for contamination of such waste water is significantly lower. The drilling wastewater will contain spent drilling fluid generated as a result of washings. The rig wash water and drilling wastewater generated is proposed to be collected in a wastewater pit (of capacity 800 m3) constructed at the drilling site. Domestic waste water generated (about 8 KLD for the drilling camp) will be treated through a soak pit/septic tank arrangement. The quantities of the liquid wastes, their characteristics and anticipated disposal methods are given in Table 2.6.
TABLE 2-6: LIQUID WASTES GENERATED DURING DRILLING AND THEIR DISPOSAL
Waste Type Quantity Disposal
Drilling and 6.2 m3 per The water will be adequately treated in an ETP to wash ensure conformance to the CPCB onshore oil and day/well Wastewater gas extraction industry effluent standards
8.0 m3 per Domestic day from Septic tank followed by soak pit Wastewater drilling site
2.8.4 Solid and Hazardous Waste Streams The different solid and hazardous waste streams generated during drilling and their disposal methodology has been presented in Table 2.7.
TABLE 2-7: WASTE STREAMS GENERATED DURING DRILLING AND THEIR DISPOSAL
Waste Type Quantity Characteristics Disposal 10 – 20 kg Organic waste Will be stored in compost pits on daily Kitchen Waste per (Non HW) basis. day/well
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Waste Type Quantity Characteristics Disposal Drill cuttings are likely to be non- Mainly Inert material hazardous due to water based mud Consisting of shales, drilling. However, as per the About 290 Drill Cuttings requirement of HWMHTM, 2008 m3/ well sands and clay; about 1% of drilling mud. Rules, the cuttings will be washed and (Non HW) contained in cuttings disposal area (HDPE lined collection pit) provided Waste Drilling Barite, Bentonite and The mud will be tested for hazardous 5 Mud (Fluid) Traces of contaminants and will be disposed m3/day/well Heavy metals (HW) according to HWMHTM Rules, 2008
2 – 3 Will be recycled through the vendors Batteries Acid – Lead supplying acid – lead batteries as per Lead – Acid (HW) required under the Batteries Batteries drilling of (Management & Handling) Rules, well 2001. Oily waste- 0.3 m3/well Will be collected in metal drums kept used oil & in secured dyked area & Disposed as 5-10 Used & Waste oil spent Oil and per Used oil rules in approved used oil Kg/well loose recycling facility Recyclables Depending - Proper segregation and storage of viz. paper, on usage recyclable waste in designated bins plastic, onsite. Recyclables will be periodically packaging sold to local waste recyclers. wastes
2.9 DRILLING HAZARDS Loss of well control / blow-out, fire, explosion and oil spills are the major potential hazards associated with drilling for oil and gas. Effective response plans to foreseeable emergencies will be developed by OIL and communicated to the project teams. A risk assessment to be carried out as part of this EIA will also contribute towards identification of hazards, risks and formulating management plans for emergency response, blowout, oil spills.
2.10 PROJECT COST Based on OIL’s previous experience of drilling in the area, cost for drilling for of 30 wells (including well site construction and site decommissioning) will be approximately INR 600 crores. The cost of drilling will depend on the depth of the well to be drilled.
2.11 HSE POLICY OIL is committed to protecting environment, health and safety of the people who may be affected, directly or indirectly by its operations. The Drilling Management System (DMS) framework lays down the corporate Health, Safety and Environment Policy for the entire organization and the range of operations it undertakes as a part of oil and gas exploration. The overall corporate health environmental safety policy of OIL may be supplemented by a local policy document whenever so required. It is understood that OIL will try to formulate a
SENES/K-20197/ November 2013 42 Oil India Ltd. Pre Drill EIA for Drilling of 30 wells at Khagarijan Field local site level policy taking from the parent corporate policy of OIL to adequately address the environmental impacts of the proposed drilling projects in Khagarijan Field through the DMS. The Corporate HSE policy of OIL is presented below: Box 2.1: OIL HSE Policy
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3 Description of the Environment
This chapter describes the existing environmental settings in the Khagarijan field and its immediate surroundings. This includes the physical environment comprising air, water and land components, the biological environment, and socio-economic environment. Attributes of the physical environment like air, water, soil, and noise quality in the surrounding area were assessed primarily through monitoring and analysis of samples collected from field. Air, traffic and noise primary monitoring was carried out by Cleenviron Private Limited (CPL), Rourkela (a NABL certified laboratory); water and soil monitoring were conducted by Mitra S. K Pvt. Ltd (also a NABL certified laboratory). All monitoring at field were undertaken under the guidance and supervision of SENES personnel during pre monsoon months of April to June, 2013. Information about geology, hydrology, prevailing natural hazards like floods, earthquakes etc. have been collected from literature reviews and authenticated information made available by government departments. Surveys were carried out to understand and record the biological environment prevailing in the area and the same was verified against published information and literature. The socioeconomic environment has been studied through consultations with various stakeholders in the villages within the Khagarijan Field. Additionally, socioeconomic data have been obtained from the Census of India reports.
3.1 PHYSICAL ENVIRONMENT
3.1.1 Climate & Meteorology Climate and meteorology of a place can play an important role in the implementation of any developmental project. Meteorology (weather and climate) plays a key role in understanding local air quality as there is an essential relationship between meteorology and atmospheric dispersion involving the wind speed/direction, stability class and other factors. The block falls under the humid sub tropical climate zone with warm.
Seasons The following are the well-defined seasons of the region: Pre-monsoon : March-May Monsoon : June- September Post-monsoon : October- November Winter : December- February
Based on the analysis of meteorological data of IMD station at Dibrugarh (Mohanbari Airport) for 2009 (January-December) and data obtained from the monitoring conducted at Tinsukia town during April-May 2013 (Refer Annex 3.1) the temperature profile, rainfall
SENES/K-20197/ November 2013 44 Oil India Ltd. Pre Drill EIA for Drilling of 30 wells at Khagarijan Field pattern relative humidity, wind speed and wind direction of the region have been discussed below1.
Photo 3.1: Meteorological monitoring at Tinsukia
Temperature Interpretation of IMD Data-2009 for Dibrugarh The average monthly minimum temperature of 8.2ºC was recorded for January 2009. Analysis of the temperature profile of the aforesaid period indicated May to September as hottest months. The month of April recorded the highest maximum average temperature at 38.1 ºC. Interpretation of Primary Baseline Data Micrometeorological data obtained for temperature as part of primary baseline monitoring undertaken for the proposed project during pre monsoon season of April to June revealed the daily maximum and minimum temperature at 40.3°C and 17.7 °C respectively. The micrometeorological values recorded for temperature have been provided in Annex 3.2
Relative Humidity Interpretation of IMD Data-2009 for Dibrugarh Relative humidity values measured twice daily at 0830 hrs and 1730 hrs at the Dibrugarh IMD station revealed high average monthly relative humidity values ranging from 54.68%- 87.65%. Maximum monthly average relative humidity values were observed in monsoon months of June to August. The average humidity values recorded for these months during
1 Automatic Weather Station (AWS, Virtual Electronics Company; Serial No.AWS – 4) was used for meteorological study
SENES/K-20197/ November 2013 45 Oil India Ltd. Pre Drill EIA for Drilling of 30 wells at Khagarijan Field both 0830 hrs and 1730 hours generally varied between 85.97% – 87.65% and 72.67% – 78.71% respectively. Interpretation of Primary Baseline Data Daily maximum and minimum Relative Humidity (RH) was recorded at 99% and 69% respectively during the primary monitoring study. The hourly variation of average relative humidity has been listed in Annex 3.2.
Rainfall Interpretation of IMD Data-2009 for Dibrugarh A total rainfall of 2307.3 mm was recorded for the year 2009 at the Dibrugarh IMD station indicating frequent rains which is generally common in these parts of the state. Rainfall begins from late April and continues up to early October, with the months of June, July and August receiving maximum rainfall. The monthly total rainfall values recorded at the Dibrugarh IMD station for 2009 have been provided as Annex 3.1. Analysis of the rainfall pattern is therefore considered important in context of the present study for effective scheduling of both drilling and testing operations. Interpretation of Primary Baseline Data About 265.8 mm of total rainfall was recorded during primary monitoring period. Fifteen rainy days were recorded with 35.4 mm being the maximum rainfall value recorded. The micrometeorological values recorded for rainfall have been provided in Annex 3.2 for reference.
Wind Speed and Wind Direction The wind speed and wind direction of an area influences the dispersal of pollutants from a point and non point sources. As the proposed drilling and testing activities involve the operation of both point (DG sets) and non point pollutant emissions sources, analysis of wind speed and direction data is considered important for predicting the air quality impacts based on pollutant dispersion. Interpretation of Primary Baseline Data Hourly micro-meteorological data collected during primary monitoring has been analyzed to generate the pre monsoon season wind rose. The predominant wind direction was observed to be from North-Northwest for the study period. The average wind speed for the months was 0.80 m/s. The wind speed was observed primarily in the range of 1.0 – 1.5m/s for the monitoring period. The calm frequency was recorded as 30.14%. The wind rose diagram generated for the primary monitoring study period and wind class frequency distribution have been presented in Figures 3.1 and wind speed & wind direction data have been provided as Annex 3.2 for reference.
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FIGURE 3-1: WIND ROSE DIAGRAM FOR PRE MONSOON SEASON
3.1.2 Ambient Air Quality Primary monitoring of the existing air environment was undertaken in the Field to establish existing ambient air quality within the proposed Field. Location of the proposed wells and the predominant wind direction is important in selection of the ambient air quality sampling stations as any gaseous and particulate emission from the project activities will disperse based on the predominant wind directions and affect the receptors located at that end. Thus the analyzed values for the pre project environment can be compared during and after the project activities. The major industrial sources of air emission at the Field are from hydrocarbon exploration and production of OIL and gas, transportation of vehicles, emission from tea garden factories etc.
Ambient air quality monitoring was conducted at 8 representative locations during April to
June, 2013. The number of monitoring stations and parameters (PM10, SO2, NO2, methane hydrocarbon, non methane hydrocarbon, VOC) for monitoring were based on the approved
ToR obtained from MoEF. However, in addition few samples for PM 2.5 were also analyzed in each monitoring station. The ambient air quality locations are shown in Figure 3.6 rationale for selection of the monitoring locations is presented in Annex 3.3.
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Air quality monitoring was carried out during the pre monsoon months of April to June,
2013, 24 hours a day twice a week for PM10, PM2.5, Sulphur Dioxide (SO2), Nitrogen di oxide (NO2), once a week for Volatile Organic Carbon (VOCs), methane and non methane hydrocarbon. A respiratory dust sampler (APM 460 DX, Envirotech Instruments Pvt. Ltd; Sl
No. 17-DATE-E-2001) was used for sampling of PM10, SO2 and NO2. Benzene sampler (AAS 172, Ecotech Instruments Sl. No. 10-A-01) was used for sampling of VOC, methane and non-methane hydrocarbon. The concentrations of various pollutants were processed for different statistical parameters like arithmetic mean, minimum concentration, maximum concentration and percentile values. A summary of ambient air quality results is presented in Table 3.1 and the detailed results are presented in Annex 3.4.
Interpretation of Air Quality Results
Particulate Matter (PM 10): The average of 24 hourly PM 10 at the monitoring locations ranged 3 between 47.38-71.94 μg/m (Figure 3.3). 98 percentile PM10 values of the stations ranged 3 between 79.40-88.50 μg/m . The average as well as 98 percentile PM10 concentrations were observed to be in compliance to the NAAQS (100 μg/m3) at all air quality monitoring locations. Lowest average value was recorded for Bharalua while the highest value was recorded for Oakland labour colony. The lower values recorded at the station were primarily due to rural set up of the Field. Comparatively higher results recorded at few stations (Oakland labour colony, Panitola, Chetiagaon etc.) were primarily to the proximity of the sites to dilapidated access roads. The statistical results of PM10 levels at the monitoring stations have been represented in Table 3.1 with Annex 3.4 bearing detailed results of such analysis.
FIGURE 3-2: AVERAGE PM 10 VALUES AT THE MONITORING LOCATIONS
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Particulate Matter (PM2.5): The average of 24 hourly PM 2.5 at the monitoring locations ranged 3 between 14.50-23.50 μg/m (Figure 3.3). 98 percentile PM2.5 values of the stations ranged 3 between 15.94-28.74 μg/m . The average as well as 98 percentile PM10 concentrations were observed to be in compliance to the NAAQS (60 μg/m3) at all air quality monitoring locations. Lowest average value was recorded for Lahoal while the highest value was recorded for Oakland labour colony. The lower values recorded at the station were primarily due to rural set up of the Field. The statistical results of PM2.5 levels at the monitoring stations have been represented in Table 3.1 with Annex 3.4 bearing detailed results of such analysis.
FIGURE 3-3: AVERAGE PM 2.5 VALUES AT THE MONITORING LOCATIONS
Nitrogen dioxide (NO2): The average NO2 values at the monitoring locations were observed in the range of 13.70-18.27 μg/m3 (Refer Figure 3.4) while the 98 percentile values ranged between 19.44-30.04 μg/m3. The average as well as the 98 percentile values complied with the 3 NAAQS (80 μg/m ) specified for nitrogen dioxide. Low values of NO2 can be attributed to the primarily rural setting of the Field. The concentration values of nitrogen oxide representative of each sampling station have been provided in Table 3.1 with Annex 3.4 bearing detailed results of such analysis.
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FIGURE 3-4: AVERAGE NO2 VALUES AT THE MONITORING LOCATIONS
Sulfur dioxide (SO2): Sulfur dioxide concentrations at locations Bharalua, Lahoal, Chabua and Panitola were found to be below detectable limit i.e. <4 μg/m3 (Refer Annex 3.4). While other 3 stations revealed mean values ranging between 4.00-4.50 μg/m . Low values of SO2 can be attributed to the primarily rural setting of the block. Methane and Non- Methane Hydrocarbon: Mean values for methane and non methane hydrocarbons at the sampling stations varied between 2.29-2.83 ppm and 0.38-0.75 ppm respectively. Highest methane and non-methane hydrocarbon values are recorded for Panitola station could be attributed to proximity of the site to NH-37. The concentration values of methane and non-methane hydrocarbon representative of each sampling station have been provided in Table 3.1 with Annex 3.4 bearing detailed results of such analysis. Volatile Organic Carbon (VOCs): Mean values of VOC varied between 1.13-2.33 ppm. Higher mean values were recorded for Panitola, while lower values were recorded for Chetiagaon and Chabua. Higher values at Panitola might be due to vehicular emission from NH-37 which is close to the monitoring stations. The concentration values of Volatile Organic Carbon (VOCs) representative of each sampling station have been provided in Table 3.1 with Annex 3.4 bearing detailed results of such analysis.
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Photo 3.2: Air Monitoring at Chetiagaon Photo 3.3: Air Monitoring at Oakland Tea Estate
Photo 3.5: Air Monitoring at Hazelbank Tea Estate Photo 3.4: Air Monitoring at Guijan Hospital
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Table 3-1: Ambient Air Quality Results Parameters
Sl No Location Statistics 3 3 3 3 HC as HC as PM 2.5 (µg/m ) PM 10 (µg/m ) SO2 (µg/m ) NO2 (µg/m ) VOC (ppm) CH4 (ppm) Non-Methane (ppm)
AQ1 Lahowal Mean 14.50 57.44 - 13.70 2.57 0.47 1.44 98 percentile 15.94 79.40 - 23.38 3.05 0.72 2.76 Max 16.00 80.00 0.00 25.00 3.07 0.72 2.90 Min 13.00 21.00 0.00 9.00 2.12 0.31 0.60 AQ2 Chetiagaon Mean 20.00 66.25 4.20 14.69 2.49 0.44 1.13 98 percentile 27.68 88.20 4.92 20.76 3.04 0.86 2.13 Max 28.00 90.00 5.00 21.00 3.08 0.89 2.20 Min 12.00 41.00 4.00 9.00 2.08 0.20 0.40 AQ3 Hazelbank Mean 20.50 62.13 4.00 15.93 2.44 0.55 1.88 TE Hospital 98 percentile 20.98 80.40 4.00 26.60 2.89 0.86 2.80 Max 21.00 81.00 4.00 28.00 2.90 0.86 2.80 Min 20.00 33.00 4.00 9.00 2.00 0.32 0.90 AQ4 Oakland Mean 23.50 71.94 4.00 18.27 2.49 0.47 1.81 Labour 98 percentile 24.94 83.80 4.00 30.04 2.92 0.85 3.62 Colony Max 25.00 85.00 4.00 32.00 2.94 0.88 3.80 Min 22.00 39.00 4.00 10.00 2.11 0.15 0.60 AQ5 Bharalua Mean 15.50 47.38 - 15.44 2.56 0.61 1.51 98 percentile 25.58 82.20 - 24.90 3.18 0.99 2.53 Max 26.00 84.00 0.00 27.00 3.24 1.02 2.60
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Parameters
Sl No Location Statistics 3 3 3 3 HC as HC as PM 2.5 (µg/m ) PM 10 (µg/m ) SO2 (µg/m ) NO2 (µg/m ) VOC (ppm) CH4 (ppm) Non-Methane (ppm)
Min 5.00 21.00 0.00 9.00 2.03 0.22 0.40 AQ6 Chabua Mean 17.00 62.69 - 13.53 2.29 0.39 1.38 98 percentile 28.52 88.50 - 19.44 2.45 0.64 2.73 Max 29.00 90.00 0.00 20.00 2.45 0.65 2.80 Min 5.00 16.00 0.00 9.00 2.09 0.21 0.50 AQ7 Guijan 8no Mean 21.50 62.50 4.50 16.33 2.41 0.38 1.50 98 percentile 27.74 83.80 5.00 24.90 2.98 0.66 2.37 Max 28.00 85.00 5.00 26.00 3.02 0.68 2.40 Min 15.00 40.00 4.00 9.00 2.04 0.12 0.50 AQ8 Panitola Mean 22.50 66.56 - 16.33 2.83 0.75 2.33 98 percentile 28.74 87.00 - 25.04 3.50 1.02 4.63 Max 29.00 87.00 0.00 26.00 3.52 1.03 4.80 Min 16.00 43.00 0.00 11.00 2.15 0.46 1.10
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3.1.3 Ambient Noise Quality The ambient noise monitoring was conducted during the winter season of 2012 at 20 locations within the Khagarijan Field. Noise stations were selected near to the proposed well locations to understand the baseline noise levels that could be impacted upon by the proposed drilling activities at the Field. Sound pressure level (SPL) measurements in dB (A) were recorded for every hour continuously for 24 hours at 15 minutes interval for the monitoring stations and equivalent noise levels in the form of Leq day and Leq night was computed. The results obtained were compared with the standard specified in Schedule III, Rule 3 of Environmental Protection Rules2. The ambient noise quality monitoring locations within the study area are shown in Figure 3.6 and the rationale for selection of the stations has been presented in Annex 3.3. Interpretation of Noise Quality Results The day time and nighttime equivalent noise levels varied between 50.0-62.7 dBA and 39.4- 49.2 dBA. The day time equivalent noise levels at 11 stations out of 20 revealed higher values were compared to the day time noise standards (55 dBA) for residential areas (Refer Figure 3.5). The night time equivalent noise levels for 4 stations (Barbari Bangaligaon, Captain Chawk, Jeraipathar, Panitola) were found to be in exceedance to night time noise standards (45 dBA). Highest day time noise levels were recorded for Panitola followed by Captain Chawk stations, both of which are located in proximity to NH-37. Similarly highest nighttime noise levels were recorded for Jeraipathar and Panitola stations both of which were also located in proximity to NH-37. Majority of the monitoring stations, however, revealed daytime and nighttime equivalent noise levels in compliance to the noise standards for residential areas. The detailed noise monitoring results are presented in Annex 3.5.
The monitoring locations with exceeding noise levels compared to the day time noise standards was probably due to proximity of the sampling stations to the NH-37, major PWD roads within the Field. Higher equivalent nighttime noise levels at Captain Chawk, Jeraipathar, Panitola was due to nighttime plying of vehicles at NH-37.
2 Sound Level Meter: SL 4001, Lutron & SLM 100, Envirotech CPL-4, 11
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FIGURE 3-5: DAY AND NIGHT TIME EQUIVALENT NOISE LEVELS
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FIGURE 3-6: LOCATION OF AIR, NOISE, METEOROLOGY AND TRAFFIC MONITORING LOCATIONS WITHIN THE KHAGARIJAN FIELD
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3.1.4 Physiography and Geology
Physiography The physical features and geology are closely related. Based on the physical features and geology, the north east of India and more specifically, the State of Assam can be divided into following physical divisions (structural units): Assam Himalayas Depositional plains of river Brahmaputra Shillong Plateau or Meghalaya Depositional plains of River Barak South-Eastern Hilly region
The Khagarijan Field falls within the depositional plains of the River Brahmaputra and its tributaries. Physiographically, the Khagarijan Field can be classified as Low-lying alluvial belt. The Brahmaputra Valley is of the nature of a “ramp” valley developed during the simultaneous upheaval of the Himalayas on the north and north east and the Patkai ranges on the south and south east. Geologically the Field can be divided in the following zone3 Alluvium: The region contains alluvium of the Recent Era, consisting of sand, gravel, pebble and clay and covers the entire Khagarijan Field and its surrounding area.
Regional Geology4 Upper Assam Basin is a proven petroliferous basin which represents a classic example of passive continental margin that evolved simultaneously with other east coast basins of India concomitant with rifting, followed by drifting of the Indian Plate from eastern Gondwanaland and its subsequent subduction underneath the Burmese and Eurasian plates. Geographically, the Upper Assam Foreland Basin is situated within the curve of the Assam Syntaxis which is a major orocline in the Himalayan Orogenic Belt. The basin has thrusted margins on three sides: to the south the Naga Hills Thrust Belt and Manipur Ophiolite Belt; to the east and north the Main Frontal Thrust of the Himalayas, which was active from the mid-Miocene to present day, bends around the Assam Syntaxis. As per sequence stratigraphic context, the shelf part of the basin consists of passive margin sediments of Late Cretaceous to Oligocene age and for deep sediments of Miocene to Recent Age with Archean granitic metamorphics
3 The classification is based upon Geological Survey of India’s Miscellaneous Publication No. 32. “Contributions to Geomorphology and Geohydrology of the Brahmaputra Valley(Plates) ”, 1977 4 Koustav Dasgupta, Saqueba Samin and Bhagwan R. Bharali. An Analysis of Pre-Tertiary Plays in Matimekhana-Deohal Area - A Case Study from OIL’s Operational Area in Northeast India. Adapted from expanded abstract presentation at AAPG International Conference and Exhibition, Calgary, Alberta, Canada, September 12-15, 2010
SENES/K-20197/ Novmeber 2013 57 Oil India Ltd. Pre Drill EIA for Drilling of 30 wells at Khagarijan Field as basement. Gondwana sediments of Early Permian and Early Cretaceous Age are locally confined between the Tertiary succession and granitic metamorphic basement.
Topography of Khagarijan Field The Khagarijan Field has almost a flat topography and in general the slope of the Field is towards the Brahmaputra River (Figure 3.7). The Brahmaputra River and Dibru River covers the entire northern part of the Field and flows from north-east to south west. In general the elevation of the Field ranges between 90-110 m from mean sea level.
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FIGURE 3-7: TOPOGRAPHIC MAP OF KHAGARIJAN FIELD
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3.1.5 Hydrogeology The Dibrugarh district is comprised of a valley underlain by unconsolidated alluvial sediments deposited over a semi consolidated Tertiary group of rocks. The area can be divided into two groups of water bearing granular zones, i.e. shallow zones to a depth of 50 metre below ground level (mbgl) and deeper zones between 50-200 m depth. Top clay layer followed by mono aquifer with a thickness of 15-45 m occurs down to a depth of 50 m below ground level constituting shallow aquifer group in most part of the district. But in flood prone area, top clay layer is absent exposing sand with occasional silt down to a depth of 50m. Ground water occurs under unconfined to semi confined condition. Grain size of aquifer material is fine to medium. On the other hand, deeper aquifer group, extending below 50m depth is seen in the northern part of the Dibrugarh district. It is mainly a single aquifer system. But in southern part of the district, the single aquifer system is separated into a multiple aquifer system by thick clay partings. Thickness of aquifer increases from east to west. Grain size of aquifer material in general is medium to coarse but fine to medium is also present. Pre-monsoon depth to water level ranges from 0.16-4.23 mbgl, whereas the post monsoon depth to water level ranges from 0.14-5.69 mbgl. Water level fluctuation ranges from 0.36-3.55m. (Source: Annual Report, 2008-09, CGWB)
Ground Water Resources On the other hand, The annual replenishable ground water resources of Dibrugarh district as per the estimate of Central Ground Water Board (as on 31st March 2009) is 1,88,911 hectare metre (ham) whereas the net groundwater availability is found to be 1,79,465 ham. The stage of ground water development is 15%. Future provision (upto year 2025) for use of ground water resources in domestic and industrial sector is 3746 ham and net ground water availability for future irrigation use is 1,51,950 ham. The annual replenishable ground water resources of Tinsukia district as per the estimate of Central Ground Water Board (as on 31st March 2009) is 1,59,036 hectare metre (ham) whereas the net groundwater availability is found to be 1,43,132 ham. The stage of ground water development is 12%. Future provision (upto year 2025) for use of ground water resources in domestic and industrial sector is 4257 ham and net ground water availability for future irrigation use is 1,25,230 ham. (Source: Dynamic Ground Water Resources in India, as on 31st March, 2009, CGWB). Groundwater is primarily used for drinking and other domestic purposes. Groundwater is primarily tapped by tube wells from depths ranging mostly between 20-35 m.
3.1.6 Ground Water Quality Primary monitoring of ground water quality was considered important in order to understand the probable impacts of the proposed project activities on the sub surface aquifers. Potential pollution of subsurface and unconfined aquifers may occur due to improper casing and cementing of well leading to infiltration or seeping of drilling chemicals or mud into nearby
SENES/K-20197/ November 2013 60 Oil India Ltd. Pre Drill EIA for Drilling of 30 wells at Khagarijan Field aquifer. Contamination of aquifers may also occur from disposal of drilling waste and mud in an open/unpaved pit. A monitoring network consisting of 10 locations for groundwater was selected and representative sampling was carried out at each of the locations (Refer Figure 3.8) and the detailed results of ground water analysis are presented in Table 3.3.
Ground Water Sampling Points A total of 10 nos. ground water samples were collected from shallow and deep tube wells of the study area comprising of Guijan 8 no village, Labour Line at Nokhrai Tea Estate, Hazelbank Tea Estate, Oakland Tea Estate, Udalguri TG Colony, Nahartoli, near Chabua College, Nakapur, Genichuk and Panitola villages. Samples were analyzed for physicochemical and bacteriological parameters and results compared with IS: 10500 drinking water standards to identify and interpret any deviation in the statutory limits set for parameters under this standard.
Interpretation of Ground Water Quality Results Turbidity Turbidity values for ground water taken at Guijan 8 No. Village, Labour line at Nokhrai Tea Estate, Nahartoli, Chabua, and Genichuk exceeded the acceptable limit as per standard i.e. 1 NTU. Among these, excepting the ground water taken at Labour line at Nokhrai Tea Estate, ground water quality of other stated villages which crossed the acceptable limit has exceeded the permissible limit (in absence of alternative source) too, i.e. 5NTU. High turbidity therefore could possibly result in the decrease in the acceptability of such water for potable purposes. However, turbidity values of groundwater collected from all the other sites were within the desirable limits of IS:10500 standards. Chlorides and Total Dissolved Solids With respect to IS:10500 standards, acceptable limit of chloride is 250 mg/l while the permissible limit of the said parameter (in absence of alternate source) is 1000 mg/l. At concentration above 250 mg/l chlorides renders a salty taste to water which may be considered to be objectionable in terms of human consumption. The chloride concentration in the ground water samples of the study area villages have been found to be well within the stipulated standards ranging from 5.99 mg/l at Oakland Tea Estate LP School to 28.5 mg/l at Hazelbank Tea Estate Hospital. The concentration of total dissolved solids (TDS) in ground water is a measure of its suitability for domestic use. In general, TDS values at 500 mg/l or below is considered to be acceptable for such purpose being specified under IS:10500 drinking water standard. The TDS values for the ground water samples analyzed varies in the range of 47.69 mg/l (Oakland Tea Estate LP School) to 119.89 mg/l (Hazelbank Tea Estate Hospital) thereby conforming to the acceptable and permissible limit as per the standard.
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Total Hardness Hardness of water is considered to be an important parameter in determining the suitability of water for domestic uses particularly washing. Hardness of water is correlated to the presence of bivalent metallic ions viz. calcium and magnesium. Total hardness values for the ground water samples analyzed ranged between 20.8 mg/l (Oakland Tea Estate LP School) to 91.52 mg/l (Guijan 8 No. village) and were found to be within the stipulated standard of 200 mg/l specified under IS: 10500. Further as discussed above, the hardness values recorded at each ground water monitoring station was found to be in correlation with the calcium and magnesium ions analyzed for such samples. The concentration of calcium and magnesium ions was found to be within both acceptable and permissible limits specified for the aforesaid parameters as per IS:10500 standards. Iron and Fluoride Iron is considered to be an important ground water parameter since at higher concentration it interferes with laundering operations and imparts objectionable stains. Iron concentration of ground water samples collected from Nahartoli (0.31mg/l), near Chabua College (1.31mg/l) and Genichuk (3.39mg/l) exceeded both the acceptable and permissible limit i.e. 0.3 mg/l as per drinking water standard. High Iron content recorded at the groundwater is probably due to local geological features of the area. Fluoride contents in the ground water samples were found to be in compliance to the acceptable and permissible limit (in absence of alternative source) of the potable drinking water standard of 1.0 mg/l and 1.5mg/l respectively. Heavy Metals The presence of heavy metals like mercury (< 0.001 mg/l), arsenic (< 0.01 mg/l), copper (< 0.02 mg/l), Hexavalent chromium (<0.05 mg/l) and cadmium (< 0.002 mg/l), in the ground water samples of all the ten sources were found to be below detection limits. However, concentration of lead at Guijan 8 no. village (0.014mg/l) and Udalguri TG Colony (0.012mg/l) was found slightly higher than its acceptable limit (0.01mg/l) as per the drinking water quality standard. Coliforms Coliform are indicators of contamination from sewage and faecal matter. Coliforms were present in all collected samples and in the concentration of 130 MPN/100ml at Guijan 8No. village, 2MPN/100ml at Labour Line at Nokhrai Tea Estate village,7MPN/100ml at Hazelbank Tea Estate Hospital, <2MPN/100ml at Oakland Tea Estate LP School, Panitola and Udalguri TG Colony, 2MPN/100ml at Nahartoli and near Chabua College, 4MPN/100ml at Nakapur and 50MPN/100ml at Genichuk. However, faecal coliform were not detected in all the collected samples. Absence of faecal Coliform in the samples did conclusively reveal the absence of faecal contamination, though high Coliform values were recorded for all the samples.
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Photo 3.6: Groundwater sampling at Hazelbank Tea Photo 3.7: Groundwater sampling near Chabua Estate Hospital College
Photo 3.8: Groundwater sampling at Guijan No. 8 Photo 3.9: Groundwater sampling at Nahartoli
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Table 3-2: Groundwater Monitoring Results
Required Permissible Guijan 8 Labour Line- Hazelbank Oakland Tea (Acceptable limit in the Udalguri TG SL. Test No. Nokhrai Tea Tea Estate Estate LP Unit Limit) absence of Colony No. Parameters (Tube Estate Hospital School alternative (Tube Well) source Well) (Tube Well) (Tube Well) (Tube Well) 1. pH 6.5-8.5 No 7.1 7.00 6.4 6.8 6.7 relaxation 2. Colour Hazen 5 15 <1.0 <1.0 <1.0 <1.0 <1.0 3. Odour - Agreeable Agreeable Unobjectio Unobjectionab Unobjectionab Unobjectionab Unobjectionab nable le le le le 4. Turbidity NTU 1 5 7.4 2.1 <1.0 <1.0 <1.0 5. Total Hardness mg/l 200 600 91.52 49.92 70.72 20.8 87.36 as CaCO3 6. Calcium as Ca mg/l 75 200 10.64 7.98 14.64 3.99 9.32 7. Magnesium as mg/l 30 100 15.59 7.19 8.19 2.6 15.37 Mg 8. Alkalinity mg/l 200 600 95.76 41.04 27.36 31.92 77.52 9. Chlorides as Cl mg/l 250 1000 7.6 11.4 28.5 5.99 15.2
10. Sulphate as SO4 mg/l 200 400 3 8.1 7.1 4 4.1
11. Nitrate as NO3 mg/l 45 No <0.5 7.85 24.34 2.08 <0.5 relaxation 12. Copper as Cu mg/l 0.05 1.5 <0.02 <0.02 <0.02 <0.02 <0.02 13. Iron as Fe mg/l 0.3 0.17 0.08 <0.05 <0.05 <0.05 14. Fluorides as F mg/l 1.0 1.5 <0.1 <0.1 <0.1 <0.1 <0.1 15. Zinc as Zn mg/l 5 15 0.03 <0.02 <0.02 0.02 <0.02
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Required Permissible Guijan 8 Labour Line- Hazelbank Oakland Tea (Acceptable limit in the Udalguri TG SL. Test No. Nokhrai Tea Tea Estate Estate LP Unit Limit) absence of Colony No. Parameters (Tube Estate Hospital School alternative (Tube Well) source Well) (Tube Well) (Tube Well) (Tube Well) 16. Phenolic mg/l 0.001 0.002 <0.001 <0.001 <0.001 <0.001 <0.001 Compound as C6H5OH 17. Mercury as Hg mg/l 0.001 No <0.001 <0.001 <0.001 <0.001 <0.001 relaxation 18. Cadmium as Cd mg/l 0.003 No <0.002 <0.002 <0.002 <0.002 <0.002 relaxation 19. Arsenic as As mg/l 0.01 0.05 <0.01 <0.01 <0.01 <0.01 <0.01 20. Lead as Pb mg/l 0.01 No 0.014 0.01 0.01 0.01 0.012 relaxation 21. Hexavalent mg/l 0.05 (for No <0.05 <0.05 <0.05 <0.05 <0.05 Chromium as Total relaxation Cr+6 Chromium) 22. Total Dissolved mg/l 500 2000 112.47 75.4 119.89 47.69 107.35 Solids 23. Total Coliform (MPN/100m Shall not be 130 2 7 <2 <2 Organism l) detectable in any 100 ml sample 24. Faecal coliform /100ml Shall not be Absent Absent Absent Absent Absent detectable in any 100 ml sample
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Ground water monitoring results (continued)
Nahartoli Permissible -Close to Required limit in the Dikom Near Chabua SL. Test Nakapur Genichuk Panitola Unit (Acceptable absence of OCS of College No. Parameters (Tube Well) (Tube Well) (Tube Well) Limit) alternative OIL (Tube Well) source (Tube Well) 1. pH 6.5-8.5 No 6.6 6.4 6.4 6.5 6.3 relaxation 2. Colour Hazen 5 15 <1.0 1.0 <1.0 5.6 <1.0 3. Odour - Agreeable Agreeable Unobjecti Unobjectionab Unobjectionab Unobjectionab Unobjectionab onable le le le le 4. Turbidity NTU 1 5 5.4 10.4 <1.0 20 <1.0 5. Total Hardness mg/l 200 600 58.24 79.04 74.88 79.04 70.72 as CaCO3 6. Calcium as Ca mg/l 75 200 6.65 9.98 10.64 6.66 9.32 7. Magnesium as mg/l 30 100 9.98 12.98 11.59 14.97 11.39 Mg 8. Alkalinity mg/l 200 600 41.04 68.4 63.84 63.84 41.04 9. Chlorides as Cl mg/l 250 1000 13.3 13.3 15.2 9.5 15.2
10. Sulphate as SO4 mg/l 200 400 2.4 4.8 4.1 <1.0 8.1
11. Nitrate as NO3 mg/l 45 No 7.3 <0.5 1.23 <0.5 8.07 relaxation 12. Copper as Cu mg/l 0.05 1.5 <0.02 <0.02 <0.02 <0.02 <0.02 13. Iron as Fe mg/l 0.3 0.31 1.32 <0.05 3.39 <0.05 14. Fluorides as F mg/l 1.0 1.5 <0.1 <0.1 <0.1 <0.1 <0.1
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Nahartoli Permissible -Close to Required limit in the Dikom Near Chabua SL. Test Nakapur Genichuk Panitola Unit (Acceptable absence of OCS of College No. Parameters (Tube Well) (Tube Well) (Tube Well) Limit) alternative OIL (Tube Well) source (Tube Well) 15. Zinc as Zn mg/l 5 15 <0.02 <0.02 <0.02 <0.02 <0.02 16. Phenolic mg/l 0.001 0.002 <0.001 <0.001 <0.001 <0.001 <0.001 Compound as C6H5OH 17. Mercury as Hg mg/l 0.001 No <0.001 <0.001 <0.001 <0.001 <0.001 relaxation 18. Cadmium as Cd mg/l 0.003 No <0.002 <0.002 <0.002 <0.002 <0.002 relaxation 19. Arsenic as As mg/l 0.01 0.05 <0.01 <0.01 <0.01 <0.01 <0.01 20. Lead as Pb mg/l 0.01 No <0.005 <0.005 <0.005 0.008 <0.005 relaxation 21. Hexavalent mg/l 0.05 (for No <0.05 <0.05 <0.05 <0.05 <0.05 Chromium as Total relaxation Cr+6 Chromium) 22. Total Dissolved mg/l 500 2000 63.72 98.32 90.85 78.6 86.56 Solids 23. Total Coliform (MPN/100m Shall not be 2 2 4 50 <2 Organism l) detectable in any 100 ml sample 24. Faecal coliform /100ml Shall not be Absent Absent Absent Absent Absent detectable in any 100 ml sample
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FIGURE 3-8: LOCATION OF GROUNDWATER, SURFACE WATER AND SOIL MONITORING LOCATIONS WITHIN THE KHAGARIJAN FIELD
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3.1.7 Drainage The study area is included under the catchment of the River Brahmaputra which flows from the north eastern side to north western side. The channels traversing through the Field are Dibru River, Dinjan River etc. The drainage pattern of the major rivers traversing the study area is discussed below.
Brahmaputra River The Brahmaputra originates near Mansarovar Lake in Tibet. After flowing through Tibet, the river enters into Arunachal Pradesh and then to Assam. Brahmaputra River flows adjacent to the block from north eastern to the north-western part. The Dibru River a major tributary of Brahmaputra flows through the north central part of the Khagarijan Field and ultimately meets with Brahmaputra near Rahmoria within the Field. The other major drainage channels within the Field are Dinjan, Maijan etc. Dinjan flows from central portion of the Field towards south west. Maijan river flows from the central portion of the Field first towards east and then towards north east to meet Brahmaputra River. Some marshy wetland areas are present near the Brahmaputra and Dibru Rivers and are used by the locals for fishing activities. The major wetland complex is known as the Maguri-Motapung wetland complex and is haven for migratory birds and is located at the north-eastern part of the Field. Though the largest water body of the complex is located outside the Field, however, two comparatively smaller wetlands (Dinjan Beel) are located near Guijan. The drainage map of the study area is presented in Figure 3.9 These surface water channels within the Field are primarily used for irrigation, bathing, washing and for catching fish. Surface run-off and discharge of drilling wastewater from the proposed wells located close to these channels have the potential to affect the water quality of these channels.
Photo 3.10: Brahmaputra River near Rahmoria Photo 3.11: Dinjan River
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Photo 3.12: Dibru River near Guijan Photo 3.13: Dinjan Beel
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FIGURE 3-9: DRAINAGE MAP OF KHAGARIJAN FIELD
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3.1.8 Surface water quality Primary monitoring of surface water quality was given importance during scoping of the EIA study as the effluent generated during the exploratory and development well drilling operations are likely to be discharged to nearby surface water bodies/natural drainage channels/rivers after ensuring that it meets prescribed norms of CPCB. Further, an effort has been made to establish the baseline quality of the existing major watersheds and sub watersheds (comprising the major drainage of the study area) to identify any possible contamination due to any current industrial activities. A monitoring network consisting of 4 locations i.e. Brahmaputra River, Dibru River and Dinjan River for surface water monitoring was selected at the water shed of Brahmaputra River. Water sampling and analysis5 was done following CPCB standard guidelines for physical, chemical and bacteriological parameters. The monitoring locations are shown in Figure 3.8.
Surface Water Sampling Points Surface water samples were collected from all major water channels of the study area i.e. Dibru River, Brahmaputra River near Oakland Tea Estate, Dinjan River and Brahmaputra River near Rahmoria. As all these water courses ultimately unite with Burhi Dihing River, therefore another sample was collected from the downstream of Burhi Dihing to get an overview of the surface water quality of the study area. Surface water quality was finally assessed against water quality criteria as per CPCB guidelines for water resources. Results of surface water samples have been discussed below.
Interpretation of Surface Water Quality Results The pH of the surface water samples varied from 7.1-7.3. The DO levels at all the locations exhibited values ranging from 6.3-7.0 mg/l indicating favorable conditions for the growth and reproduction of normal population of fish and other aquatic organisms in the these water bodies. BOD values in all the surface water samples were detected at concentration below 3.00 mg/l. Such low BOD values confirmed the presence of low concentrations of biologically oxidizable organic matter in the receiving water bodies. The COD values of all the monitoring stations were found to be less than 4.0 mg/l except at the Brahmaputra River near Oakland Tea Estate (11.84mg/l). Electrical conductivity values of the samples ranged between 0.04-0.11 millisiemens/cm, Sodium Absorption Ratio varied between 0.09-0.19. Free ammonia contents of all the samples were found to be less than 0.1 mg/l. The total Coliform count of the surface water samples varied between (11 MPN/100ml) at Dinjan River to 80 MPN/100ml at Dibru River.
5 http://www.cpcb.nic.in/latest/guidelines-water.doc
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The presence of contaminants in the form of oil and grease in all surface water sources was found to be negligible. Iron content in all the surface water sample varies from <0.05mg/l to 3.66 mg/l whereas chromium content was found to be negligible (<0.01mg/l). The toxic organic component, phenol, was also found be below detectable limit (<0.001 mg/l) in all the surface water samples. Detailed surface water analysis results have been provided at Table 3.3. As discussed in the previous section the channels from which samples were taken and analyzed were primarily used for irrigation, bathing, cleaning and for catching fish. The analyzed values of the samples after comparing with the CPCB Water Use Criteria (Refer Annex 3.6) justifies their use in compliance to water use criteria.
TABLE 3-3: SURFACE WATER QUALITY RESULTS
Brahmaputra Brahmaputra Dibru River near Dinjan SL. No. Test Parameters Unit River near River Oakland Tea River Rahmoria Estate 1. Temperature 0C 28 26 30 28 2. Free Ammonia mg/l <0.1 <0.1 <0.1 <0.1 3. pH at 260C - 7.2 7.1 7.3 7.2 4. Dissolved mg/l Oxygen 6.2 6.3 7 6.3 5. BOD (3 days at mg/l 270C) <2.0 2.1 <2.0 <2.0 6. COD mg/l <4.0 11.84 <4.0 <4.0 7. Electrical µs/cm Conductivity at 250C 112 109 44.6 112 8. Sodium - Absorption Ratio 0.09 0.099 0.19 0.1 9. Boron mg/l <1.0 <1.0 <1.0 <1.0 10. Oil & Grease mg/l <1.4 <1.4 <1.4 <1.4 11. Total Dissolved mg/l Solids 79.3 78.2 27.7 77.8 12. Total Suspended mg/l Solids 282.8 424.4 <2.5 506 13. Dissolved mg/l Phosphate <0.15 0.31 <0.15 0.46
14. Nitrate as NO3 mg/l 1.13 0.99 0.58 1.2 15. Chlorides as Cl mg/l 3.8 5.7 7.6 5.7
16. Sulphate as SO4 mg/l <1.0 2 <1.0 <1.0 17. Iron mg/l 3.09 3.36 <0.05 3.66
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Brahmaputra Brahmaputra Dibru River near Dinjan SL. No. Test Parameters Unit River near River Oakland Tea River Rahmoria Estate 18. Total Chromium mg/l as Cr <0.01 <0.01 <0.01 <0.01 19. Phenolic mg/l compound as C6H5OH <0.001 <0.001 <0.001 <0.001 20. Total Coliform mg/l Organism 80 23 11 50
Photo 3.14: Surface water sampling from Dibru River Photo 3.15: Surface water sampling from Brahmaputra River near Oakland Tea Estate
Photo 3.16: Surface water sampling from Dinjan Photo 3.17: Surface water sampling from Brahmaputra River near Rahmoria
3.1.9 Land-Use and Land Cover The land-use and land-cover of the Khagarijan Field has been interpreted from the satellite data (LANDSAT Imagery), toposheet of the area, and subsequently by ground truthing during field surveys. The study area land use shows that majority of the land within the Field (28.86%) is covered by the main course of Brahmaputra River, Dibru River, other small channels, riverbed and water bodies. The tea garden areas also cover a major part of the Field (21.31%). About 14.8% of the total land area is used for agricultural purpose. About 9.91%
SENES/K-20197/ November 2013 74 Oil India Ltd. Pre Drill EIA for Drilling of 30 wells at Khagarijan Field area of the Field is covered by grasslands present at the river islands of Brahmaputra and Dibru Rivers. Forest areas, comprising primarily of Dibru-Saikhowa National Park and Padumoni Segment of Bherjan-Borajan-Padumoni Sanctuary cover about 8.97% of the total Field area. Among the Forest land about 8.64% of the total area of the Field (approximately 51 sq km) is included under Dibru-Saikhowa National Park. The National Park area includes grasslands, river courses, vegetated areas, settlements etc. Settlements and homestead land plantation comprise about 12% of the total area of the Field. Defence installations cover about 1.91% of the total Field area. Open scrub land cover 0.14% of the total area. Roads, including the NH-37, Rangagora road, Balijan-Dinjan road, other PWD roads and tea garden roads comprise 1.02% of the Field area. Industrial units including facilities of OIL, godowns near NH-37, few brick kilns etc. comprise 0.40% of the total area. The part of Mohanbari Airport comprise of 0.4% of the Field area. The percentage distribution land use categories have been shown in Figure 3.10 and the land use map is presented in Figure 3.11.
FIGURE 3-10: PERCENTAGE LAND USE-LAND COVER DISTRIBUTION OF KHAGARIJAN FIELD
Out of 30 wells, 15 wells are located within plantation areas of tea garden 12 wells are located in agriculture land, 2 wells located in household tea garden areas and 1 well within forest land.
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FIGURE 3-11: LAND USE MAP OF KHAGARIJAN FIELD
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3.1.10 Soil Quality Soil character of cultivable land in Tinsukia district is mainly alluvial and composed of mixture of sand (coarse to fine) and clay in varying proportions. The general geochemical characteristic of the soil of the region is moderate to slightly acidic. The alluvial soils of the Brahmaputra valley are highly fertile and are suitable for raising of varieties of crops (such as cereals, pulses, oilseeds, plantation crops etc.) round the year. The well drained, deep, acidic alluvial soils of upper Assam with good proportion of phosphoric content are mostly suitable for the paddy plantation. The new alluvial soils formed due to inundation of land by river at intervals contain high percentage of fine sand, fine silt and are less acidic. Such soils are often neutral and even alkaline. Large expanses of low-lying land are characterized by heavy clayish soil with a high percentage of nitrogen and organic matter which is appropriate for rice cultivation. Soils of the Dibrugarh district are basically the products of fluvial processes of the Brahmaputra and its tributaries. The plains are composed of alluvium which may be classified as new and old. The new alluvium varies mostly from clayey to sandy loam in texture and is slightly acidic in reaction. It is found in the vast plain of the district along the river valleys, especially in their lower courses. The old alluvium on the other hand, occurs in upper and middle parts of the valley. It occurs mainly in Joypur, Tipling, Kheremia and Tengakhat mouzas in the form of terrace deposits. These deposits contain alternating beds of pebbles, gravel or boulder with loose sand and clays. (Source: DPR of IWMP for Dibrugarh-2 Watershed (Kalakhowa)
As discussed above, since soils of the Brahmaputra Valley, of which the Khagarijan Field is a part is characterized by fertile alluvium the implementation of the proposed project may lead to the temporary change/loss of soil fertility at the drilling site. The understanding of soil quality therefore assumes significance considering the block soil fertility characteristics and also given the responsibility of the proponent to restore the site back to its original condition following decommissioning. An effort has been therefore been made to establish the soil quality of the block through primary monitoring study as discussed in the section below.
Primary Soil Sampling and Analysis The soil characteristics within the study area, especially the physical quality and fertility of the soil have been characterized by analyzing the soil samples collected from 5 locations namely, Plantation area at Udalguri Tea estate, Forest Land near Padumoni Block of Bherjan- Borajan- Padumoni (BBP) Sanctuary, agricultural Land near Mokalbari Kanoi Tea Estate, agricultural land near Poilabari and Plantation area at Balijan Tea Estate. As described in Section 2.5 that proposed wells will be drilled in agricultural land, tea gardens and forest lands, emphasis has been given in selection of soil quality monitoring locations, so that it can encompass all aforesaid types of land. The soil collected was analysed for heavy metals with the objective of establishing baseline values for such contaminants. The soil sampling location points are shown in Figure 3.8.
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Interpretation of Soil Analysis Results Soil Quality of Agricultural Lands The texture of soil samples collected from Agricultural land near Mokalbari Kanoi Tea Estate and in Poilabari was found to be Clayey in nature. The sand percentage of the samples were found to be 17.6% and 27.3% respectively, whereas silt percentage of the collected samples were found to be 20.3% and 26.4% respectively. On the other hand clay percentage of the soil sample collected from agricultural land was found to be 62.1% and 46.3% respectively. The pH level in soil samples were recorded as 4.52 and 4.99 respectively indicating strongly acidic soils as per standard soil classification. Electrical conductivity is used to estimate the soluble salt concentration in soil, and is commonly used as a measure of salinity. The EC values for soil samples collected from Agricultural lands near Mokalbari Kanoi Tea Estate and Poilabari were found to be 177.7 microsiemens/cm and 28.71 microsiemens/cm respectively. The soil samples collected from Agricultural lands near Mokalbari Kanoi Tea Estate and Poilabari revealed high available nitrogen content (193.12kg/ha and 167.37 kg/ha respectively), which is suitable for paddy cultivation. The available phosphorus and potassium content of the soil also revealed suitability of the soil for paddy cultivation. Heavy metals viz. iron, copper, zinc and manganese are important soil micronutrients being considered essential for the normal growth of plants. Deficiencies of micronutrient drastically affect the plant growth and metabolism. The micronutrient levels of iron (122.94 kg/ha and 119.48 kg/ha respectively), copper (6.12 kg/ha and 3.35 kg/ha respectively), zinc (20.56 kg/ha and 19.45 kg/ha respectively) and manganese (52.41kg/ha and 40.63 kg/ha respectively) observed in the soil samples taken from agricultural Lands near Mokalbari Kanoi Tea Estate and Poilabari do not indicate any extraordinary enrichment of metals or contamination from any external sources and the concentrations agree to the general natural composition of soils. The sodium hazard of soil usually is expressed as the Sodium Adsorption Ratio (SAR). The SAR values in the soil samples collected from Agricultural Lands near Mokalbari Tea Estate and Poilabari were found to be 0.11 and 0.13 respectively. Soils with high levels of exchangeable sodium may cause dispersion of soil particles leading to the replacement of major cations (calcium and magnesium) adsorbed on the soil. This could possibly to lead to deterioration of soil structures and water infiltration problems. Further, soil analysis results exhibits higher concentration of calcium (218.75kg/ha to 153.12 kg/ha respectively) ions compared to sodium (35.71 kg/ha for both the samples). Higher Ca2+ values observed in the samples are indicative of good soil permeability and structure.
Soil Quality of Tea Gardens The texture of soil samples collected from Udalguri Tea Estate and Balijan Tea Estate were found to be Sandy Loamy and Clayey respectively. The sand percentage of the samples were found to be 56.5% and 14.7% respectively, whereas silt percentage of the collected samples
SENES/K-20197/ November 2013 78 Oil India Ltd. Pre Drill EIA for Drilling of 30 wells at Khagarijan Field were found to be 23.9% and 21.1% respectively. On the other hand, clay percentages of the tea garden samples were found to be 19.6% and 64.2% respectively. The pH levels in soil samples collected from Udalguri and Balijan Tea Estate were recorded as 4.32 and 3.53 respectively indicating strongly acidic soils as per standard soil classification. The EC values for soil samples collected from Udalguri and Balijan Tea Estate were found to be 70.85 microsiemens/cm and 242.06 microsiemens/cm respectively. The soil samples revealed that the available nitrogen content of the soil is high i.e. 180.25kg/ha (sample taken at Udalguri Tea Estate) and 193.12 kg/ha (Sample taken at Balijan Tea Estate). The soil of tea gardens also contained good organic carbon content 1.52% and 1.72% respectively. Heavy metals viz. iron, copper, zinc and manganese are important soil micronutrients being considered essential for the normal growth of plants. The micronutrient levels of iron (40.92kg/ha and 50.16 kg/ha), copper (5.62kg/ha and 13.42 kg/ha respectively), zinc (24.06 kg/ha and 39.78 kg/ha respectively) and manganese (208.13 kg/ha and 224.65 kg/ha respectively) observed in the soil samples taken from Udalguri and Balijan Tea Estate do not indicate any extraordinary enrichment of metals or contamination from any external sources and the concentrations agree to the general natural composition of soils. The SAR values in the soil samples collected from Udalguri and Balijan Tea Estate were found to be 0.14 and 0.23 respectively. Further, soil analysis results exhibits higher concentration of calcium (503.12 kg/ha to 109.37 kg/ha respectively) ions compared to sodium (53.57 kg/ha and 62.5 kg/ha respectively).
Soil Quality of Forest Land The texture of soil sample collected from Forest Land near Padumoni Block of BBP Sanctuary was found to be clayey in texture. The sand percentage of the sample was found to be 12.2%, whereas silt percentage of the collected sample was found to be 18.1%. On the other hand, clay percentage of the sample collected from forest land was found to be 69.7%. The pH level in soil sample collected was recorded as 4.90 indicating strongly acidic soils as per standard soil classification. The EC value of the soil sample was 61.05 microsiemens/cm. The sample revealed high available nitrogen content i.e. 218.87kg/ha. The soil also contained high organic carbon content of 1.75% natural for forest land soil. Heavy metals viz. iron, copper, zinc and manganese are important soil micronutrients being considered essential for the normal growth of plants. Deficiencies of micronutrient drastically affect the plant growth and metabolism. The micronutrient levels of iron (53.24kg/ha), copper (8.16 kg/ha), zinc (29.56 kg/ha) and manganese (143.31 kg/ha) observed in the soil samples taken from Padumoni Block of BBP Sanctuary do not indicate any extraordinary enrichment of metals or contamination from any external sources and the concentrations agree to the general natural composition of forest soils. The SAR values in the soil samples collected from Padumoni Block of BBP Sanctuary was found to be 0.08. The detailed soil analysis results have been provided at Table 3.4.
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TABLE 3-4: SOIL ANALYSIS RESULTS
ate
SL. Test Parameters Unit
No.
near Poilabari
BBPSanctuary near Mokalbari
Forestland near
KanoiTea Est
Agricultural Land Agricultural Land
Balijan Tea Estate
PadumoniofBlock UdalguriTea Estate
1. Texture - Sandy Clay Clay Clay Clay loam 2. Moisture % 21.5 24.36 25.51 23.26 21.81 3. Sand % 56.5 12.2 17.6 27.3 14.7 (W/W) 4. Silt % 23.9 18.1 20.3 26.4 21.1 (W/W) 5. Clay % 19.6 69.7 62.1 46.3 64.2 (W/W) 6. Organic Matter % 2.62 3.02 2 1.24 2.07 7. Alkalinity as mg/kg Nil 19.8 19.8 19.8 Nil CaCO3 8. Acidity as mg/kg 19.8 Nil Nil Nil 39.6 CaCO3 9. Specific gravity - 2.39 2.19 2.39 2.48 2.19 10. pH(1:2.5) at 4.32 4.9 4.52 4.99 3.53 0 26 C - 11. Electrical 70.85 61.05 177.77 28.71 242.06 Conductivity at µs/cm 250C 12. Available mg/kg 403.76 490.28 432.6 374.92 432.6 Nitrogen 13. Available mg/kg 42.06 <3 12.8 10.5 47.04 Phosphorous 14. Available mg/kg 60 120 80 40 400 Potassium 15. Available Ca mg/kg 1127 588 490 343 245 16. Available Mg mg/kg 1381.8 1176 1117.2 940.8 882 17. Chloride as Cl mg/kg 49.48 74.23 74.23 49.48 98.97
18. Sulphate as SO4 mg/kg 130.15 162.58 518 401.38 438.6 19. Total organic 1.52 1.75 1.16 0.72 1.72 Carbon % 20. Fe mg/kg 91.67 119.26 275.4 267.65 112.38 21. Cu mg/kg 12.6 18.28 13.72 7.52 30.08
SENES/K-20197/ November 2013 80 Oil India Ltd.
Pre Drill EIA for Drilling of 30 wells at Khagarijan Field
ate
SL. Test Parameters Unit
No.
near Poilabari
BBPSanctuary near Mokalbari
Forestland near
KanoiTea Est
Agricultural Land Agricultural Land
Balijan Tea Estate
PadumoniofBlock UdalguriTea Estate
22. Zn mg/kg 53.91 66.23 46.07 43.59 89.11 23. Pb mg/kg 11.2 17.4 12.4 10 23.2 24. Mn mg/kg 466.22 321.02 117.42 91.02 503.22 25. B mg/kg 0.51 <0.5 1.64 <0.5 0.69 26. Na mg/kg 120 60 80 80 140 27. Sodium 0.14 0.08 0.11 0.13 0.23 Absorption Ratio (SAR) -
Photo 3.18: Soil sampling from Udalguri tea estate Photo 3.19: Soil sampling from Agricultural land near Poilabari
3.1.11 Transport and Traffic The major road within the Khagarijan Field is NH 37 (which connects Dibrugarh and Tinsukia town with the state capital Guwahati). All the well locations can be approached through roads arising from NH 37. Traffic count survey was conducted at two locations viz. near Chetiagaon on Chabua to Rahmoria road and near Borguri on Tinsukia to Guijan road, to have a better understanding of the traffic density pattern of the Khagarijan Field and to assist the proponent in planning vehicular movement during drilling operation. The locations were selected based on the assessment of the road network on the GIS imageries and through reconnaissance surveys undertaken by SENES team. The traffic count was monitored continuously for 24 hours once during the study period at 2 locations. Traffic survey was conducted for vehicles categorized
SENES/K-20197/ November 2013 81 Oil India Ltd. Pre Drill EIA for Drilling of 30 wells at Khagarijan Field into heavy vehicles (truck, bus, trailer, lorries, etc.), four wheelers (car, matador, jeep, etc.), three wheelers (auto, tempo, etc.) and two wheelers (motorcycle, etc.). The traffic survey results are provided in Table 3.5 and the traffic monitoring locations are shown in Figure 3.8.
TABLE 3-5: TRAFFIC MONITORING RESULTS
Two Three Light Heavy Total Traffic Stations Wheeler Wheeler Vehicles Vehicles (nos.) (nos.) (nos.) (nos.) (nos.) Chabua to Rahmoria road 250 76 81 52 459 near Chetiagaon Tinsukia to Guijan road 262 65 91 75 493 near Borguri
Interpretation of Traffic Survey Results Traffic load of both of the monitoring locations were found to be more or less same ie. 459 near Chetiagaon and 493 near Borguri. At Chetiagaon highest vehicular traffic (65nos.) was recorded during 1600-1700 hours, while the lowest vehicular traffic load was recorded at 0300-0400 hrs (2nos.). Percentage distribution of traffic load reveal 17.65% light vehicles, 11.33% heavy vehicles, 54.46 % two wheelers and 16.56% three wheelers. Highest vehicular traffic load at Borguri was recorded at 1600-1700 hrs (49 nos.) while the lowest load was recorded during 0300-0400 hrs (3 nos.). Percentage distribution of traffic load reveal 15.21% heavy vehicles, 18.46% light vehicles, 53.14 % two wheelers and 13.19% three wheelers.
Hourly traffic data has been provided at Annex 3.7.
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3.1.12 Natural Hazards A natural disaster during the life cycle of the project can have a significant effect on the functioning of the project in addition to affecting the local environment in the area and stressing the availability of resources for the project. Such disasters also sometimes create difficulties in access through disruption of transportation links.
Seismicity & Earthquakes The study area is located in Zone V as shown in the Bureau of Indian Standards (BIS) 2000 seismic zone map for India (refer Figure 3.12). Zone V is defined as region which might encounter earthquakes of maximum intensity.
FIGURE 3-12: SEISMIC ZONE MAP OF The region has experienced a large number of INDIA earthquakes of tectonic origin. The risk probabilities of earthquake are less over the entire Brahmaputra valley. Two major earthquakes of magnitude 8.7 (occurred in 1897) and 8.6 (in 1950) causing large scale damage to lives and properties in this region. The details of the earthquakes are given in Table 3.6.
TABLE 3-6: SIGNIFICANT EARTHQUAKES IN ASSAM Date of Location of Remarks Quake Epicentre 12 June Near Rangjoli, Magnitude M 8.0. This was one of the most powerful earthquakes in the 1897 Assam Indian sub-continent. The quake wreaked havoc across the present states of Assam and Meghalaya. 1500 people were killed and hundreds more hurt. 15-Aug- Indo-China Magnitude M 8.6. This "Independence Day" earthquake was the 6th largest 50 Border Region earthquake of the 20th century. Though it hit in a mountainous region along India's international border with China, 1500 people were killed and the drainage of the region was greatly affected.
[Source : Amateur Seismic Centre www.asc-india.org]
Floods One of the most serious problems of Assam is the occurrence of frequent and widespread floods. The Brahmaputra and the Barak are the two main rivers, which causes major problem during the monsoon period every year in the form of floods thereby resulting in bank erosion and drainage congestion. Large areas are inundated by floods causing heavy loss in terms of life and property; and also cause extensive damage to standing crops thereby affecting local livelihood. The flood history of Assam is given in Table 3.7.
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TABLE 3-7: FLOOD HISTORY OF ASSAM Affected Population Total Damage (in Year Affected Area (lakh ha) (Lakh) Crores INR) 1990 0.488 1.692 74.56 1991 0.997 5.307 191.15 1992 0.213 0.974 26.56 1993 1.348 5.261 0.215 1994 0.053 0.177 0.20 1998 0.972 4.698 700.00 2000 1.000 3.900 244.06 2001 0.200 0.540 11.14 2002 1.960 6.960 210.95 2004 All of the 27 districts, 122.0 NA worst affected districts, Karimganj, Cachar, Nagaon and Golpara
It was revealed from the Flood Hazard Maps (1998-2007) prepared by National Remote Sensing Agency (NRSA) that parts of the Khagarijan Field is flood prone and the flood prone areas were classified as “very low”, “low”, “moderate”, “high” and “very high” based on the occurrence of floods (Table 3.10). Majority of the proposed exploratory and development wells were not located at the flood prone zones. However, few wells were located at “very low”, “low” and “moderate” and “high” probability zones where 10 year flood record (1998- 2007) revealed 1-2 times, 3-4 times, 5-6 and 7-8 times of occurrence of floods. The wells located at different flood prone zones are depicted at the table below and shown at Figure 3.13.
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TABLE 3-8: PROPOSED WELLS LOCATED AT FLOOD PRONE LOCATIONS
Classification based on probability Probability of Sl. No. Well Number of occurrence of flood Occurrence of Flood 1 Very low 1-2 times 2, 11, 27, 30 2 Low 3-4 times 29 3 Moderate 5-6 times 4, 16, 17, 18, 24 4 High 7-8 times 13 5 Very High 9-10 times None 6 Not in flood prone zone 0 time 1, 3, 5, 6, 7, 8, 9, 10, 12, 14, 15, 19, 20, 21, 22, 23, 25, 26, 28
Consultation with locals, however, revealed that floods generally occur at sites located in proximity to Brahmaputra River and Dibru River. Inundation levels at these areas were reported to be 0.3-0.5 metres and potential period of water logging is between June- September.
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FIGURE 3-13: WELLS LOCATED AT THE FLOOD PRONE ZONES OF DIBRUGARH AND TINSUKIA DISTRICTS
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3.2 ECOLOGICAL ENVIRONMENT The Dibrugarh and Tinsukia district is rich in biodiversity and has a number of sensitive ecosystems comprising both terrestrial and aquatic components. Biogeographically this area exhibits the properties of both the Indian and Malayan Sub-regions so International Union for Conservation of Nature & Natural Resources (IUCN) delineated this area within Indo Burma Hotspot (Refer Box 3.1). Under the classification of Wild Life Institute, Dehradun this area falls within North Eastern India-Brahmaputra valley Bio-geographical province (9A).
The primary objectives of the biological environment study are:
To assess the vegetation types To identify common flora & fauna in the study area To find out rare and endangered floral and faunal species To evaluate wildlife habitat of the area and assess impact of the proposed project on wildlife & their habitats. To assess impact of the proposed project on agriculture and domestic livestock.
3.2.1 Methodology
Study Area The study area for terrestrial ecological surveys is considered taking the entire area of Khagarijan Field. However, the study area for aquatic ecological survey extends from Brahmaputra River in north to Dinjan in south as the entire Field is located within the watershed of Brahmaputra River.
Desktop Review and Reconnaissance Survey
A desktop review (management plan and other published document etc.) was conducted to determine the forest area (Toposheet and Satellite imagery), vegetation type (Champion and Seth, 1962), floral and faunal assemblage in the study area. A site reconnaissance visit was conducted during April 2013 to identify different ecological habitats, sensitive ecological habitat and also to identify the targeted study area for baseline survey.
Baseline Survey Baseline survey was carried out to determine the existing ecological conditions and was designed to fill any data gaps, and to facilitate an adequate assessment of the project’s impacts upon ecology and the development of appropriate mitigation measures. Baseline survey was conducted from April to June, 2013 for habitat survey, flora & faunal assemblage, in the study area. Baseline survey has two parts- (i) Secondary data collection and (ii) Primary Survey.
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Secondary Data Collection Secondary baseline data regarding sensitive ecological habitat (National Park, Sanctuary, Ecological Sensitive Area, Migratory Corridor, etc.), flora & fauna in the study area, forest cover was collected for Forest Department’s website; Management Plan of protected areas and other publish and unpublished documents. Stakeholder consultations (Forest Department, Local People, Panchayat, etc) were also carried out to understand the major flora & fauna in the study area, pressure on forest resources, presence of any Schedule I species. Primary Survey Primary survey was carried out the targeted study area for habitat (terrestrial and aquatic), flora and faunal survey (terrestrial and aquatic). Special attention was paid to those areas, which will be directly impacted by proposed drilling activity. Box 3.1: Biodiversity of Indo-Burma Hotspot
The proposed oil field falls under Indo- Burma hotspot, one of the twenty-five richest biodiversity hotspots of the world. The Indo- Burma hotspot comprises of about 2 million square kilometers of tropical Asia, east of the Indian sub-continent. The region includes all of Cambodia, Laos, nearly the entire territories of Thailand, Myanmar and Bhutan, parts of Nepal, far eastern India and extreme south China, Hanian Islands in South China sea and the Andaman Islands. The region is still revealing its biological treasurers. A wide diversity of ecosystem is represented in this hotspot including mixed wet evergreen, dry evergreen, deciduous, and montane forests. There are also patches of shrub lands some coastal areas. In addition, a wide variety of distinctive localized vegetation formations occur in Indo-Burma, including lowland floodplain swamps, mangroves, and seasonally inundated grasslands. A conservative estimate of total plant diversity in the hotspot reveals about 13,500 vascular plant species, of which about, 7,000 (52 percent) are endemic. Among the flora of the Indo-Burma Hotspot are a wide array of orchid and ginger species and many tropical hardwood trees, including commercially valuable dipterocarp species and teak (Tectona grandis). There are about 430 mammal species in the hotspot; more than 70 species and seven genera are endemic. Six large mammal species have been discovered in the last 12 years. Nearly 520 reptile species are found in the hotspot; 12 genera and over 200 species are endemic. Nine of the endemic genera are represented by a single species. Indo-Burma also supports probably the highest diversity of freshwater turtles in the world: 53 species, representing one-fifth of the world's species There are more than 280 amphibian species in the Indo-Burma hotspot, over 150 of which are endemic. However, high endemism does not extend to the genus level; only three of 46 genera are restricted to the hotspot. Indo-Burma has a remarkable freshwater fish fauna, with more than 1,260 documented species, or about 10 percent of the world’s freshwater fishes. More than 560 of these species are endemic. The Hoolock Gibbon (Hylobytes hoolock) is the only ape species in India, is the western most of the nine species of lesser apes in South-east Asia. Its distribution is restricted to the monsoon and evergreen rain forests of Northeast India south of Brahmaputra River, Bangladesh, Southern Yunnan and Myanmar up to the river Chindwin. Gibbons inhabit primary evergreen and less seasonal parts of semi-evergreen rain forest, and very rarely semi- deciduous forests.
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3.2.2 Terrestrial Ecosystem
Forest & Flora Forest Resources: The Khagarijan Field falls under Tinsukia and Dibrugarh districts. Tinsukia district has 1536 sq. km under the forest cover, i.e. 40.53 percent of its total geographical area (State of Forest Report 2011, FSI). The forest cover of the district comprises of 106 sq. km (6.9%) very dense forest, 699 sq. km (45.5%) moderately dense forest and 731 sq. km (47.6%) of open forest. Dibrugarh district has 758 sq. km under the forest cover, i.e. 22.42 percent of its total geographical area (State of Forest Report 2011, FSI). The forest cover of the district comprises of 29 sq. km (3.8%) very dense forest, 165 sq. km (21.8%) moderately dense forest and 564 sq. km (74.4%) of open forest. About 51 sq km area of Dibru-Saikhowa National Park dominates the north eastern part of the Khagarijan Field. Along with that 1.76 sq km of Padumoni Segment of Bherjan-Borajan-Padumoni Sanctuary of Tinsukia district present within this Field. OIL will drill 30 exploratory and development wells in this Khagarijan field. Out of 30 planned wells, 14 wells fall within 10 km of both Dibru-Saikhowa National Park as well as Bherjan Borjan Padumoni Wildlife Sanctuary and 14 wells are located within 10 km of only Dibru-Saikhowa National Park and 1 well is situated within 10 km of only Bherjan Borjan Padumoni Wild Life Sanctuary. Distances of wells located within 10 km of sanctuary and national park are presented in Table 3.11 and Figure 3.16.
Forest Types Owing to the huge amount of annual rainfall, forest types occurring in this region are primarily of Tropical Evergreen Forest and Tropical Semi-Evergreen Forest. Apart from forest having luxuriant tree growth different types of swamp forests as well as extensive grasslands can also be found in areas which remain water logged for particular time of the year. (Champion and Seth Forest classification). 1/1/1B/C1 Assam valley Tropical wet evergreen forest: The forest is characterized by several layers of canopy. The top canopy is dominated almost entirely by Dipterocarpus macrocarpus which occurs in patches, attaining girth of 7m and height up to 40 Meters. Other species found in the top canopy are Amoora walllichii, Terminalia myriocarpa, Artocarpus chaplasha. They stand over a closed evergreen middle canopy of about 30m, which is mostly dominated by Mesua ferrea and Vatica lanceaefolia. The other species that grow sporadically in the lower canopy are Terminalia belerica, Canarium resiniferum, Terminalia chebula, Sapium baccatum, Dysoxylum binectiferum etc. There is also a undergrowth of mainly composed of woody shrubs like Kasidoria (Myrsine capitellata), Osbekia spp., Sorat (Laportea crenulata), Kaupat (Phrynium placentarium), Borgitora (Alpinea allughas) etc. climbers and epiphytes are also abundant. This type of forest can be found in Borajan and Padumoni segments of Bherjan Borajan Padumoni Wild Life Sanctuary and isolated patches of Dibru Saikhowa National Park.
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1/2/2B/C1a Assam Valley Tropical semi evergreen forest: This forest is mainly characterised by a closed, largely evergreen community of trees with varying proportion of deciduous trees, mainly as a broken top storey. Less uniform and imposing than the tropical evergreen forest but still including tall and large trees. Middle story is dense and varied undergrowth including much cane etc. Buttresses are a common feature and strangling figs are numerous. This type of forest can be found in core area of Dibru Saikhowa National Park and Bherjan and Borajan sections of Bherjan Borajan Podumoni Wild life sanctuary. Main species of this type of forest include Artocarpus chaplasha, Alphonsea ventricosa, Castonopsis indica, Canarium spp., Dillenia indica, Dysoxlum procerum, Mesua ferrea, etc. The undergrowth and climbers are Myrsine capitellata, Osbekia spp., Laportea cranulata, Phrynium placentarium etc. 1/2/E1 Cane brakes: It is mainly characterized by an impenetrable thorny thicket sometimes with a few tall trees standing over it, sometimes without. The stems are typically trailing, but some species are more or less erect. Within the study area this forest can be found in the core of Dibru Saikhowa National Park. Some of the species that represent this type of forest are Calamus sp, Arundo donax etc. 1/3/3C/C3b East Himalayan moist mixed deciduous forests: This forest is mainly characterized by a tall more or less closed forest in which the individual trees often of quiet large size. Community is mostly well mixed but there is a dominance of deciduous species that grows on well drained soil. There is an abundant undergrowth of mostly shrubs but no grass unless burnt. With burning grass many become abundant with coarse tufted species absent. This type of forest can be found in Dibru Saikhowa National Park. Some of the species that can be found in this forest are Lagerstroemia sp, Terminalia bellerica, Amoora sp. etc. 1/3/1/S2b Eastern Hollock Forests: This forest is mainly characterized by extensive stretch of tall grass savannah forest with occasional scattered trees growing in areas which receive a minimum rainfall of 1500mm. large trees like Terminalia myriocarpa or Lagerstoemia sp are mostly predominant. Other species that can be found are Vatica lanceaefolia, Duabanga Sp, Pterosparmum acerifolium etc. This type of vegetation can be found in Dibru Saikhowa National Park. 1/4/4D/SS1 Eastern seasonal swamp forests: This forest is mainly characterized by even and dense forest with canopy at about 20m. For the greater part of rain the soil remains water logged. This type of vegetation can be found in Bherjan and Borajan part of Bherjan Borajan Padumoni Wild Life Sanctuary. Some of the species that can be found in this forest are Altingia excelsa, Michelia doltsopa, Dillenia indica, Terminalia chebula, Bischofia javanica, etc. 1/4/4D/SS2 Barringtonia swamp forests: This forest is characterized by open crop of evergreen trees of medium height mostly comprised of few species, often pure crop, but it may be much denser and with or without a thick undergrowth of evergreen species. Some of the ground, particularly the higher parts, may be under course savannah grass. Climbers are few. The most important factor that promotes in this types forest growth is annual flood
SENES/K-20197/ November 2013 90 Oil India Ltd. Pre Drill EIA for Drilling of 30 wells at Khagarijan Field during monsoons. This is the most abundant forest type in the Dibru-Saikhowa National Park. Species mostly associated with this forest are Salix tetrasperma, Bischofia javanica, etc. 1/4/4D/2S1: Eastern wet alluvial grasslands: Vegetation is mainly dominated with sea of grass growing up to 2m in height with occasional trees growing up to 3 m in height. In the higher land Mesua ferrea becomes predominant in the top canopy. Associated with it are found other species namely Altingia excels, Michelia doltsopa, Dillenia indica, Terminalia chebula, Bischofia javanica etc.
Flora There are different varieties of flora and fauna in the forests of the state of Assam. The north- east including Assam has 6000-7000 plant species identified so far. Plant resources of Assam are concentrated mainly in the tropical and semi-evergreen forests, grasslands, wet deciduous and riverside forests. There are at least 100 varieties of orchids available in Assam. Floral Composition of Padumoni section of Bherjan Borajan Padumoni Wild Life Sanctuary: Padumoni part of the Bherjan Borajan Padumoni Wild Life Sanctuary is characterized by Assam valley Tropical wet evergreen forest (1/1/1B/C1). Major portion of the forest of this part of the protected area is characterized by this forest type. The forest is composed of several canopy layers. The top canopy is dominated almost entirely by Hollong (Dipterocarpus macrocarpus) which grow upto 40 Meters. The other species that are found to occur sporadically are Amoora wallichii, Terminalia myriocarpa, Artocarpus chaplasha, Altingia excelsa, Michelia champa etc. Middle canopy is dominated by Mesua ferrea and Vatica lanceaefolia. The other species that grow sporadically in the lower canopy are Terminalia belerica, Canarium resiniferum, Terminalia chebula, Sepium baccatum, Dysoxylum binectiferum etc. The undergrowth is composed of woody shrubs like Kasidoria (Myrsine capitellata), Osbeckia spp., Sorat (Laportea creanulata), Kaupat (Phrynium placentarium), Bogitora (Alpinea allughas), etc. are also found. Floral Composition of Dibru-Saikhowa National Park: The original natural vegetation of the National Park was tropical wet evergreen rainforest (1/1/1B/C1 Assam valley Tropical wet evergreen forest) with grassland and reed beds (1/4/4D/2S1: Eastern wet alluvial grasslands and 1/4/4D/SS: Eastern seasonal swamp forests) in the riverine tracts and depressions. During the great earthquake of 1950, large parts of the reserve sank by a few meters, resulting in the regular flooding of the area. This was followed by the emergence of a new type of vegetation. ‘Salix swamps’ (1/4/4D/SS2 Barringtonia swamp forests) and deciduous forest now dominate the reserve, and evergreen forest is now restricted to a few patches. About a third of the national park is covered with Salix tetrasperma and Bischofia javanica—the most abundant tree species. Dipterocarpus macrocarpus trees, which were common before 1950, are now rare. Grassland and reed beds cover another third of the park (1/3/1/S2b Eastern Hollock Forests and 1/4/4D/2S1: Eastern wet alluvial grasslands). The main reed and grass species are Arundo donax, Phragmites karka, Imperata cylindrica, Saccharum spp. etc. The core area of Dibru Saikhowa Biosphere Reserve is a mosaic of habitat types, the diversity of which is reflected in the faunal diversity
SENES/K-20197/ November 2013 91 Oil India Ltd. Pre Drill EIA for Drilling of 30 wells at Khagarijan Field it supports. The core is characterized by littoral and swamp forests, semi-evergreen forests, deciduous forests and patches of wet evergreen forests. Apart from this 38 species of orchid can be found in the Dibru Saikhowa National Park. Non-Forest Vegetation: The land use land cover study reveals that about 70% area Khagarijan Block is under non-forest area. A large number of plant species also recorded in the non-forest area. Tree species in these sites are mostly planted and few are natural. Block plantation and tea garden with shade trees, village woodlot are also recorded in the study area, these are as follows: Road side Plantation: Trees planted along the major roads in the study area. Some important tree species are Alistonia scholaris, Anthrocephalus sinensis, Azadirchta indica, Acacia auriculoformis, Artocarpus heterophyllus, Delonix regia, Phyllanthus embilica, Ficus religiosa, Mangifera indica, Lagerstroemia speciosa. Village Woodlot: Naturally or planted trees on community or private land. Bamboo and timber woods are planted in this area. Some important tree species are Mangifera indica, Aegle mermelos, Delonix regia, Dalberjia sisso, Ficus religiosa, Ficus bengalensis, Gmelina arborea etc. Tea Garden &Shade Tree: Most of the tea gardens have shade trees and plantation along the garden roads. These are mostly nitrogen fixing plant species, viz. Albizzia sp. Cassia siamea, Gmelina arborea, Shonka arvenis, Artocarpus heterophyllus. Riparian Vegetation: Vegetation along river bank, major plant species are Anthocephalus sinensis, Alistonia scholaris, Bombax ceiba, Terminalia arjuna, etc. Floral Diversity: Due to the presence of Dibru Saikhowa National Park and Bherjan Borjan Padumoni Wild Life Sanctuary in the Khagarijan Block floral diversity in the study area is fairly rich. 274 numbers of plant species was reported from the area, which includes 152 species of trees, 53 species of shrubs and herbs, 12 species of climbers, 19 species of grasses and 38 species of epiphytes. The detailed listing of floral species recorded in the study area is given in Annex 3.8. Endemic, Threatened & Endangered Floral Species The Wildlife (Protection) Act 1972 prohibits picking, uprooting, damaging, destroying, acquiring or collecting six species of plants from forest land and any area specified, by notification, by the Central Government [Clause 17A of Chapter IIIA (Protection of Specified Plants), page 346 of Handbook Vol. 1]. The six species are: Beddome’s cycad (Cycas beddomei), Blue Vanda (Vanda coerulea), Kuth (Sassurea lappa), Ladies slipper orchids (Paphiopedilum spp.), Pitcher plant (Nepenthes khasiana), Red Vanda (Rananthera imshootiana). None of these species is recorded in the forests of the study area during the EIA.
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Wildlife Habitat
A habitat survey was carried out both in the Khagarijan Field and its immediate vicinity. Assam is home to a number of charismatic mammalian fauna Rhino, Elephant, Tiger, Pygmy hog, Hispid hare, Golden langur, Leopard, Golden Cat, Clouded leopard, Himalaya palm civet, Binturong, Himalayan black bear, Sloth bear, Gaur, Water buffalo, Sambar, Hog deer, Barking deer, Swamp deer etc. Wildlife in Assam is given protection through a network of 5 National Parks, 20 Wildlife Sanctuaries, three Tiger Reserves and five Elephant Reserves. A significant part of the Khagarijan Field falls within the south western part of Dibru Saikhowa national Park. Also the Padumoni Segment of Bherjan-Borajan-Padumoni Wildlife Sanctuary is located within the Khagarijan Field. Apart from these two protected areas tea garden plantation covers huge tracts of land within the block as well as in the surrounding region. As tea gardens have very low human population density and settlement within them are isolated and patchy, tea gardens acts as wildlife movement corridor between isolated protected areas, as well as habitat for huge diversity of avian fauna and even large cats like leopards. Khagarijan Field with proposed wells and ecological sensitivity of the area is presented in Figure 3.14.
Box 3.2: Bherjan - Borajan - Padumoni Wildlife Sanctuary
The sanctuary is made up of three separate patches of forest located around Tinsukia town. From Tinsukia town - Bherjan block is 3 kms away, Borajan block is 6 kms away and Padumoni block is 5 kms away. Total size of the sanctuary is 7sq km. The sanctuary is popular for the tropical semi-evergreen forests and the surrounding beautiful tea estates. Bird watching is a popular activity in this sanctuary.
Mammal: Bherjan-Borajan-Padumoni Wild Life Sanctuary has been recognized as a prime habitat for seven primate species. These are Hoolock Gibbon (Hylobates hoolock), Slow Loris (Nycticebus coucang), Pig Tailed Macaque (Macaca nemestrina), Assamese Macaque (Macaca assamensis), Capped Langur (Presbytis pileatus), Stump Tailed Macaque (Macaca arctoides) and Rhesus Macaque (Macaca mulatta). Primate populations are more prominent in Borajan part of the Sanctuary. This part of the protected area consists of considerably large patches of tropical wet evergreen forest. Study conducted by individual researchers have indicated that Borajan part of the forest has enough food trees and resting places for primates. In Bherjan & Padumoni, Hoolock gibbon is not found but other primates are commonly sighted in these two parts. Apart from primates few leopards, wild pigs, lesser cats, etc. have made this sanctuary as their home. The Sanctuary also provides home for different species of squirrels such as common giant flying squirrel (Petaurista petaurista), Pallas’s squirrel (Callosciurus erythraeus), Irrawaddy squirrel (Callosciurus pygerythus.) etc. Birds: 84 species of birds have been found including Osprey, Kingfisher, Indian Pied Hornbill, Lineated Barbet, Woodpecker, Drongo, Common Mynah, Bulbul, Magpie Robin, Wagtail and varieties of woodland birds.
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Box 3.3: The Dibru-Saikhowa National park
The Dibru-Saikhowa National Park and Biosphere Reserve is located in Tinsukia and Dibrugarh districts of Assam. A small part of the buffer zone is in Dhemaji district. The area lies in the Indo-Burma Global Biodiversity Hotspot. The terrain of the park is flat and it is situated in the floodplains of the Brahmaputra and the Lohit Rivers. The buffer along with the core is also significant in the fact that it forms an overlap for two major avian migratory flyways- the East Asian and central Asian. The Maguri-Motapung wetland complex near the buffer in Guijan, in fact, is a haven for migratory birds. The elevation of the park varies from 110– 126 above mean sea level. Other rivers that traverse along the park are the Dibru and the Dangori. The area of the biosphere reserve is 765 sq km which is managed on a core-buffer strategy. 340 sq km of the area constitutes the core while the remaining 425 sq km constitutes the buffer. The core area of DSBR is a mosaic of habitat types, the diversity of which is reflected in the faunal diversity it supports. The core is characterized by littoral and swamp forests, semi-evergreen forests, deciduous forests and patches of wet evergreen forests. Mammal: Wide range of habitats of the National Park houses about 36 wild mammal species. Apart from small cats like jungle cat and leopard cat, big cats like tiger, leopard and illusive clouded leopard can be found in the national park. A wide range of grazers from large Asian Elephant and Wild Asian Water buffalo to small herbivores like hog deer and barking deer makes the park their home. Unique animals like Bengal slow loris, Himalayan Hoary-bellied squirrel, Malayan Crestless Porcupine, Chinese pangolin, feral horse and many others can be found in the park. Owing to the presence of creeks and rivers within the national Park as well as in its surrounding viable population of aquatic mammals like Gangetic river dolphin and Eurasian otter are also present in the park. Birds: About 500 species of birds can be found in Dibru-Saikhowa National Park. In fact, the area is so rich in avian biodiversity that BNHS, along with Birdlife International have declared the core as an Important Bird Area [A1 (Threatened Species) & A2 (Endemic Bird Area 131: Assam Plains)] while Stattersfield (1998) has classified Dibru-Saikhowa as Assam Plains Endemic Bird Area. The core is home to highly range-restricted avifauna, such as the Marsh prinia, Black breasted Parrotbill and the Jerdon’s Babbler. Resurrection of highly endangered avifauna like the Bengal Florican and white winged wood duck is a distinct reality at Dibru- Saikhowa. Herpeto fauna: The national park is home to 18 amphibian species, 11 species of turtle, 18 species of lizard including 2 species of monitor lizard and 23 species of snakes. Fishes: As many as 104 species of fishes are found in the Dibru-Saikhowa national Park. Future Prospect of Dibru-Saikhowa National Park: About 22% of the core is grassland and the complex of tall wet grasslands and swamps make this ecosystem highly productive, diverse and conducive as a habitat for the rhinoceros. So this area is recognized as a rhinoceros translocation site under the Indian Rhino Vision 2020 (IRV 2020). The core of the Biosphere Reserve is also a potential translocation site for the Eastern Soft Ground Swamp Deer/ Barasingha(Cervus duvauceli ranjitsinhji) which is known to exist only in Kaziranga National Park. In future the park may be given the status of Tiger as well as elephant reserve.
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FIGURE 3-14: ECOLOGICAL SENSITIVITY MAP
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The different animal habitats observed at the study area are described below: Primate Habitat: The tropical wet evergreen forests of the area provide an ideal habitat for primate species. In Tinsukia district, the Hoolock gibbon occurs in all regions excluding the wide riverbeds of the Brahmaputra and Lohit (Figure 3.15) as is evident from the distribution pattern. Tea gardens, roads, railway and large human settlements have resulted in fragmentation. Within the Khagarijan Field Hoolock gibbon population is present within the core of Dibru Saikhowa National Park. Though Padumoni section of the Bherjan Borajan Padumoni Wild Life Sanctuary is located inside the field area, hoolock gibbon population is not reported from there. Hoolock Gibbon population is only reported from the Borajan Segment of Bherjan-Borajan-Padumoni Wildlife Sanctuary, which is located about 4.5km from Khagarijan Field area. In Bherjan & Padumoni other primates like Assamese macaque (Macaca assamensis), Pig tailed macaque (Macaca nemestrina), Rhesus macaque (Macaca mulatta), Capped Langur (Presbytis pileatus), are reported. Species which are not strictly confined to top canopy like Rhesus macaque and Pig tailed Macaque can be found throughout the study area, including in proximity to the settlements.
FIGURE 3-15: HOOLOCK GIBBON HABITAT IN TINSUKIA DISTRICT [Source: Anwaruddin Choudhury; The Hoolock Gibbon (Hoolock hoolock) in Tinsukia and Dibrugarh districts of Assam, India, Asian Primates Journal 1(2), 2009]
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Carnivores: Within the study area large cats like Tiger and Clouded leopard are present only in the core areas of Dibru-Saikhowa National Park. But another member of the big cat family Leopard, is much more widely distributed in the study area. It is found in the forest segments of Bherjan Borajan Padumoni Wild life Sanctuary. Apart from that large portion of the Khagarijan Field area is under tea garden plantation. This large tea garden plantation also acts as leopard habitat. Since there is virtually no prey base within the forest segments of Padumoni and Bherjan, leopards prefer residing in surrounding tea gardens where prey in the form of dogs and livestock is available6. So leopard can be encountered around well locations located within tea garden estate (well 1, 5, 7, 8, 12, 14, 15, 19, 20, 21, 22, 13, 25, 26, 28). Other small cats like jungle cat and leopard cat is found in the protected areas within the block as well as in the tea garden plantation. Other carnivores like Sloth bear, Wild dog, Jackal is found in Dibru-Saikhowa National Park7. Jackal is also found in the protected forest patches of Bherjan-Borajan-Padumoni Wild Life Sanctuary. Herbivores: Within the Khagarijan Field no large herbivores permanently resides outside the Dibru-Saikhowa National Park. Within the National Park area Different types of forests, extensive grassland and marshes provide ample food like grass, bamboo, berries, shrubs fruits, aquatic vegetation etc. that supports large herbivores like Asian Elephants and Wild Asian buffalo. The national park also houses a unique large herbivore that is feral horse (True semi wild, borne free and living free). About 79 feral horses are reported from the National Park. Though these large herbivores live inside the National park, during monsoon when the National park gets flooded, Elephants and Wild Asian Buffalo crosses the Lohit River and takes temporary refuge in the Tea gardens of Dinjan and Guijan area. So during rainy reason Elephants and Wild Asian Buffalo are reported encountered near proposed Well 1, Well 22 and Well 28. Elephant Corridor The buffer along with the core forms an integral constituent of the Dibru-Deomali elephant corridor which has been cited as an important movement pathway for elephants (Choudhary, 1999). Elephants from Deomali Forest Division in Tirap district of Arunachal Pradesh are known to move around in the buffer of DSNP and Digboi area of Tinsukia district (Varma et.al., 2008). It may well be concluded from these two studies that the buffer forms a vital component of elephant migration in the area, and with the elephant being declared as a heritage animal, the value of managing the buffer assumes greater importance. Birds - Such rich is the avian biodiversity of the place that Bombay Natural History Society (BNHS), along with Birdlife International have declared the core of Dibru-Saikhowa National Park as an Important Bird Area [A1 (Threatened Species), A2 (Endemic Bird Area 131: Assam Plains)] while Stattersfield (1998) has classified Dibru-Saikhowa as Assam Plains Endemic Bird Area. The core is home to highly range-restricted avifauna, such as the
6 Management Plan: Bherjan-Borjan-Padumoni Wild Life Sanctuary 2013-2013 to 2017-2018 7 Management Plan for Dibru Saikhowa Biosphere Reserve 2011-2012 to 2015-2016
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Marsh prinia, Black breasted Parrotbill and the Jerdon’s Babbler. Different types of habitats in Dibru-Saikhowa National Park supports critically endangered avian species like Bengal Florican, which needs wide open grass land. Another endangered bird that can be found the park is white winged wood duck, which needs dense tropical evergreen forest near rivers or swamps to survive. Four nests of White-winged Duck have been reported by the Forest Department. Most of the recent sightings have been listed in Choudhury (2006)8 and historic records in Green (1992). A notable record from IBA is sighting of a pair of Sarus Crane, the first sighting of the species in north-east Indian for several decades. This record has extended their range by 500 km. The two Critically Endangered Gyps species of vultures were not uncommon during 1992-94, but now both are very rare. During a survey in October 2001, no Oriental White-backed Vulture Gyps bengalensis and Slender-billed Vulture Gyps tenuirostris were reported (Choudhury, 2002). The buffer along with the core is also significant in the fact that it forms an overlap for two major avian migratory flyways- the East Asian and central Asian. Again in the north eastern corner of the Khagarijan Field, near Guijan, Maguri-Motapung wetland complex is situated. It is considered as a haven for migratory birds. Dibru-Saikhowa area is among the most important wintering sites in Assam of the Black Stork Ciconia nigra (Choudhury 1997)9.
Faunal Diversity
Mammals: Altogether 230 forms including species and subspecies have been recorded or are likely to be found in Assam (Choudhary, 199710). This is one of the highest diversity of mammals in any of the Indian states i.e. 60% of the total mammalian species found in India. Mammals within the study area are represented by 36 species of large and smaller mammals. The checklist of mammals in the study area is given in Annex 3.9. These include several species of herbivore and carnivores. The Asian Elephant and Wild Asian Buffalo are the major herbivore in the study area as a significant part of the Khagarijan Field falls under Dibru- Saikhowa National Park which also part of Dibru-Deomali elephant corridor. The Tiger, Clouded leopard and Indian leopard are the large carnivore reported in the OIL field. Among them Leopard is widespread within the protected areas and tea garden plantation within the Khagarijan Field. Rest of the big cats ranges are confined within the Dibru-Saikhowa National Park. Apart from the large carnivores, the presence of a number of lesser carnivores was recorded from the study area. These include the Jungle cat, Jackal,
8Choudhury, A.U, 2006. Birds of Dibru-Saikhowa National Park and Biosphere Reserve, Assam, India. Indian Birds Vol. 2 No. 4, pp- 95-105. 9Choudhury, A.U. 1997. The status of the birds of Dibru-Saikhowa Sanctuary, Assam, India. OBC Bull. 25: 27– 29 10Choudhury, A.U. 1997. Checklist of the Mammals of Assam. Revised 2nd Edition. Guwahati : Gibbon Books and ASTEC, 103 pp.
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Small Indian civet, Large Indian civet, Small Asian mongoose, Indian Grey Mongoose, Chinese pangolin and Himalayan Crestless Porcupine.
The study area is especially important as a primate habitat. There is record of Hoolock Gibbon in the Borajan Segment of Bherjan-Borajan-Padumoni Wildlife Sanctuary and Dibru-Saikhowa National Park. The other primate species recorded in the study area include the Rhesus Macaque, Assamese macaque, Capped langur and Slow loris. Avifauna: About 958 species and subspecies of birds have so far been reported or likely to occur in Assam. This is the highest diversity of birds in any of the Indian states. Arunachal Pradesh comes next with more than 750 species. About 500 species of birds were reported by the Forest Department from Dibru-Saikhowa National Park. All the wells are located in the non-forest area, mainly tea garden; the primary survey (around 1 km around the well sites) results show that avi-fauna diversity was quite low compared to avi-faunal diversity in the Protected area. Primary survey recorded 45 avian species from the study area (Annex 3.10). However, detailed checklist obtained from forest department revealed presence of about 502 species of birds. The detailed avian checklist provided by the forest department has been provided at Annex 3.11. Critically endangered species like Bengal Florican were also reported from study area. Reptilian Species: At least 187 species have been reported or likely to be found in Assam. This includes two species of crocodiles, 21 turtles and tortoise, 46 lizards and 118 snakes (including three species of monitors). The presence of diverse reptilian species is highest in any of the Indian states. Reptilian fauna in the study area is represented by 23 species of snakes including Burmese Rock Python, Eastern Cat Snake, Indo-Chinese Rat Snake, King Cobra, White-lipped Pit Viper etc. In the study area 11 species of turtle can be found like Malayan box turtle, spotted pond turtle, Indian soft shell turtle and endemic Assam Roofed turtle. About 9 species of lizards like Bengal Monitor, White spotted Supple Skink, Indian Garden Lizard etc can be encountered in the study area. The detailed checklist of reptilian species has been presented in Annex 3.12.
Endemic, Endangered & Threatened Fauna The non- forest area and forest area form the habitat of some endangered and threatened species which are listed in the Schedule I of the Indian Wildlife (Protection) Act, 1972 and amendment in 1991. Secondary information revealed presence of thirty species of Schedule I animals. Out of thirty one Schedule I species, thirteen species belong to mammals and ten species belong to birds and eight are reptiles. (Refer Table 3.9).
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TABLE 3-9: SCHEDULED ANIMAL SPECIES IN THE STUDY AREA
Wildlife Sl. Scientific Name Common Name IUCN Category Schedule No. A. Schedule I A.1 : Mammals A.1.1 Elephas maximus Elephant Endangered A.1.2 Prionailurus bengalensis Leopard Cat Least Concern A.1.3 Hylobates hoolock Hoolock Gibbon Endangered A 1.4 Panthera pardus Leopard Near Threatened A.1.5 Presbytis pileatus Capped langur Vulnerable A 1.6 Nycticebus coucang Slow Loris Vulnerable A 1.7 Platanista gangetica Gangetic Dolphin Endangered Neophelis nebulosa Clouded Leopard Vulnerable A 1.8 (within core of DSNP) A 1.9 Nycticebus bengalensis Slow Loris Vulnerable A 1.10 Babalus arnee Wild Asian Buffalo Endangered A.1.11 Trachypithecus pileatus Capper langur Endangered Panthera tigris Tiger Endangered A 1.12 (within core of DSNP) A 1.13 Manis pentadactyla Chinese Pangolin Endangered A.2 : Birds A.2.1 Anthracoceros albirostris Oriental pied hornbill Least Concern A.2.2 Bucerus bicornis Great pied hornbill Near Threatened White-ramped Critically A 2.3 Gyps bengalensis Vulture Endangered A 2.4 Aviceda jerdoni Jerdon’s Baza Least Concern Critically A 2.5 Houbaropsis bengalenisis Bengal Florican Endangered White-bellied Heron Critically A 2.6 Ardea insignis Endangered White-winged Wood Endangered A 2.7 Cairina scutalata duck A 2.8 Platalea leucorodia Eurasian Spoonbill Least Concern A 2.9 Gracula religiosa Common Hill Myna Least Concern Slender-billed Critically A2.10 Gyps tenvirostris Vulture Endangered A.3: Reptiles A 3.1 Python molurus Asiatic Rock Python Near Threatened
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Varanus bengalensis Indian Monitor Least Concern A 3.2 Lizard A 3.3 Varanus salvator Water monitor Least Concern Nilssonia gangeticus Indian Soft Shelled Vulnerable A 3.4 Turtle A 3.5 Pangshura trntoria Indian Tent Turtle Least Concern A 3.6 Geoclemys hamiltoni Spotted Pond Turtle Vulnerable A 3.7 Pangshura sulhetensis Assam Roofed Turtle Endangered Nillsonia hurum Indian Peacock Vulnerable A 3.8 Softshell turtle
3.2.3 Aquatic Ecosystem Aquatic Habitat: The Khagarijan Field falls within the catchment of Brahmaputra River which flows through the north western part of the block. The Dibru-Saikhowa National Park in the north eastern part of OIL Field provides diverse types of aquatic habitat. The National Park is basically a flood plain of the river Brahmaputra and Siang in the north, Lohit and Dibang to the east, the Anantnala to the south east and the Dangori and Dibru in the south. The entire area is traversed by several rivulets and nallahs and is completely inundated in the monsoons. The area literally being an island, the area forms an isolated fluvial ecosystem subject to vagaries of the monsoon and accompanying floods. There are a large number of perennial and seasonal channels which criss-cross the core area. Some important channels are Kolomi, Salbeel nala, Dadhia Nala, Chabru Nadi, Laikajan, Anantanala, Dimoruhola and Nayanadi. In addition to these, some small and seasonal channels are developed during rainy seasons which arise from the main channels. Apart from the above there are several perennial beels and marshes in different locations of the Park. Some such beels are Raidang, Burhi, Tilakbam, Thekera, Kathgora, Banko, Hatighuli, Dighali, Kurhimari, Rongmola, Tarali, Koliapani etc. Nagapathar, Schoolgorapathar, Pagalipathar etc. are important beels and marshes among the seasonal beels and marshes which normally remain dry during winter and full of water during summers. During severe monsoons, the erosive power of the rivers and nallahs is such that new channels are regularly cut giving rise to a network of interconnected water channels. In the eastern part of the Khagarijan Block, the Maguri-Motapung wetland complex near the southern buffer of Dibru-Saikhowa National Park is another important wetland habitat within the field area. Two wetland areas located near Guijan, known as Dinjan beels are also part of the Maguri-Motapung wetland complex. The largest wetland (Maguri beel) is located just outside the boundary of Khagarijan Field. More or less through the southern side of the Khagarijan field flows the perennial Dinjan, which flows from east to west and ultimately drains into Brahmaputra River outside the field. Apart from these perennial water bodies, a significant number of seasonal water bodies are present in the Field. One such is the silted bed of Mai Jan that extends more or less through the centre of the Field. It is a long stretch of low land that remains dry for most of the year, but during monsoon and post monsoon
SENES/K-20197/ November 2013 101 Oil India Ltd. Pre Drill EIA for Drilling of 30 wells at Khagarijan Field months it becomes water logged resulting in a continuous stretch of wetland. In majority part of this wetland paddy is cultivated. Following aquatic ecological groups has been studied. Macrophytes: Seasonal wetlands and marshy lands are suitable habitat for aquatic macrophytes. The most dominant macrophytes are Phragmites karka, Arundo donax, Alternantha sessilis, Cyperus iria, Hydrilla verticillata and Nymphoides cristrat. A total of 13 species of aquatic macrophytes were recorded from these aquatic ecosystems (Annex 3.13). Fishes & Fisheries: Freshwater fish species in the wetlands of Assam has been well represented. Major fish fauna of fresh water bodies include catla, rohu, mrigala, bata, calbous, safari punti, titpunti, maurala, chela, folui, boal, pabda, lata, shole, kholse, pancal, baan, tilapia (exotic), tangra, singi, techoka, magur, koi, bele, kuchia etc. Wilderness fishes like chanda, ghute etc., are now rare due to the indiscriminate use of organochlorine pesticides which contaminate the run-off from agricultural fields and flow into the wetlands from their catchments areas. A total of 21 species of fishes were reported from these aquatic ecosystems. (Annex 3.14). Amphibia: Of the 206 amphibians species known from India, about 18 species were reported from this area during the study period (Annex 3.15). Aquatic Reptilia: The survey results show 14 species of aquatic turtle like Malayan box turtle, spotted pond turtle, Indian soft shell turtle and endemic Assam Roofed turtle. Majority of these turtles are found in the Brahmaputra River and Dibru-Saikhowa National Park. (Annex 3.16). Water Birds: Some common water birds like Pond heron and Indian cormorant are common throughout the Khagarijan Field. But due to the presence of Dibru-Saikhowa National Park and Brahmaputra river highly elusive and rare water birds can be found in the northern side of the Field. A small breeding population of endangered White-winged Duck was reported within the Dibru-Saikhowa National Park. It is one of the sites in the northeast where highly endangered and elusive White-bellied Heron was reported. Migratory water birds like endangered birds like Nordmann’s Greenshank were also reported in the National park. Some bird species like Jerdon’s Babbler and Marsh Babbler were reported to be closely associated with the tall grass and reed beds found in the marshy wetlands within the National park (Annex 3.17). Aquatic Mammals: Two aquatic mammals were reported from in the study area, they are Eurasian otter (Lutra lutra) and Gangetic Dolphin (Platanista gangetica). Both of these two animals can only be encountered in the Brahmaputra River and the numerous streams flowing through the Dibru-Saikhowa National Park.
3.2.4 Agricultural Diversity Agriculture is the main economic activity in this district. A major crop in the district is paddy and tea. Other important crops are maize, rape and mustard, sesamum, sugarcane, pineapple
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3.3 SOCIOECONOMIC ENVIRONMENT This section discusses the baseline socio-economic environment of the Khagorijan Oil and Gas Field in the districts of Dibrugarh and Tinsukia with respect to OIL’s proposed exploratory and development well drilling operations. The following section discusses the methodology used for the socio-economic assessment. The subsequent sections discuss the baseline profile of the district and the villages within the study area. The information provided has been primarily derived from the secondary sources (Census of India and District Statistical Handbook). In addition primary information was also collected during the discussions at the villages with the local community members. The informal public consultations have been used to validate the Census 2001 data. The village-wise secondary data (obtained from Census, 2001 and presented) has been taken into consideration for analyzing the socio-economic profile in a comparative manner for the Khagarijan Field. As the study area defined for the proposed project encompasses relevant districts of Assam (Tinsukia and Dibrugarh) the profiling of the project socioeconomic environment has focused primarily on the villages located in the aforesaid districts.
3.3.1 Methodology A socio economic assessment of the positive and negative impacts on the people likely to be directly and indirectly affected by the project was conducted along with other studies during the EIA study. The assessment facilitated an understanding of the needs, demands, preferences, capacities and constraints of the people in the vicinity of the project operation. It was undertaken primarily to enhance the understanding of other relevant factors such as social organizations and networks, livelihood patterns, social infrastructure etc and thus helped prioritising OIL’s commitment towards the CSR initiatives. Inputs from the social assessment into the design phase facilitated in: Tracking potential adverse effects over different time frames and different activities Reviewing options to eliminate such negative impacts through design changes or mitigate them through specific social protection or mitigation measures Reviewing options to extend or enhance benefits for the population in the vicinity of the project site.
The social assessment was primarily based on the analysis of the secondary data obtained from the census survey (2001 and provisional data of 2011) and stakeholder consultations. Considering the nature of the project operations and understanding of the demographic characteristics of the area from the secondary data the following tools was used for the gathering information and validating the secondary data to carry out the assessment.
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Stakeholders Identification At the beginning of the EIA process, the SENES team conducted a preliminary identification of probable stakeholders. An inventory of actual / potential stakeholders, including local groups and individuals, local institutions like the panchayats which may be directly or indirectly affected by the project or with interest in the development activities of the region. This inventory was arrived through discussions with OIL personnel and members of the local community. The local communities which would primarily be affected were identified based on the location of the tentative drilling operations as proposed by OIL. The villages were selected within 1-2 km radius of the proposed well location considering the fact that there might be potential impacts on the socio-economic-cultural and environment of the local communities residing in these villages. For further assessment of socioeconomic issues and impacts on different stakeholders detailed consultations with the community were planned. The discussions focused on the issues of population/demography, education profile, medical facilities and amenities like drinking water, transport and communication and also on primary and secondary occupation of the villagers.
Consultations
Consultations with key stakeholders are a continuous process that was carried all through the EIA process and would be continued during the construction and operation phases of the project. The stakeholder analysis was followed by discussions with some of the key stakeholders to identify their dependence on the affected or shared resources, the extent of impact on them and measure, which will be undertaken to mitigate these impacts. Issues like land and resource damage, social disturbance, severance and increased congestion, noise and air pollution, employment opportunities, need for development of basic infrastructure, safe drinking water, sanitation facilities in the surrounding villages were discussed during the consultations so that they can be adequately addressed through the environment management plans. The consultations also helped in developing preliminary understanding of the requirement of social development initiatives, which are required in the project village and may be undertaken as part of the OIL’s CSR activity.
3.3.2 General Socioeconomic Profile The Khagorijan Oil and Gas Field falls in the districts of Tinsukia and Dibrugarh of Assam. The Field is located mostly in Dibrugarh district. Assam accounts for nearly 2.57% of the country’s population as per the Provisional Population Totals of Census 2011. Out of the total population, 87% is still rural. The population of the state has increased at the decadal growth rate of 18.92% between 1990-01 and 16.93% between 2001-1. In fact Assam is the most populous state in the North-Eastern region and the provisional figures of Census 2011 shows an increase in the population density from 340 in 2001 to 397. The 2001 Census represents the sex ratio of Assam as 935 females per 1,000 males. The provisional figure of Census 2011 shows an improvement in the sex
SENES/K-20197/ November 2013 104 Oil India Ltd. Pre Drill EIA for Drilling of 30 wells at Khagarijan Field ratio which is presently 954 females per 1000 males. The Scheduled caste and Scheduled tribe population are 1.83 million (6.86%) and 3.31 million (12.41 %) respectively (Census 2001). As per Census 2001, Assam has a total of 4914823 households and the average household size is 5.4 persons per household. The gross decadal migrants as a percentage of total urban population in 2001 are 7.12. While the gross decadal inter-state migration is insignificant, the gross decadal intra-state migration of males and females as a percentage of total male and female urban population in 2001 is 5.75 and 6.22 respectively (Mitra 2008)11. According to a study by Nath, 201212, there has been undocumented migration in Assam especially in the districts bordering Bangladesh. The study shows that the growth has been remarkable among religious groups of Muslims and among linguistic groups of Bengali speaking population. The study utilized Leslie matrix population projection model to estimate the undocumented migrated population and it turned out to be 830755 and 534819 respectively during 1971- 91 and 1991 – 2001. The reduction in the migration figures during the last decade points is mainly due Assam Accord where the Assam state government along with the Government of India had played an important role in checking the immigration from the bordering country. The Tinsukia district of Assam comprises of 3 administrative divisions. The administrative divisions are further subdivided into 7 nos. C.D. Blocks. There are 11 nos. police stations, 4 nos. revenue circle, 1138 inhabited villages and 88 Gram Panchayats in the district. The geographical area of Tinsukia district is 3790 sq. km. The total population of the district as per 2001 census is 1150062 which has increased to 1316948 (provisional figures of Census 2011) indicating a decadal growth of 14.51%. The present decadal growth rate is lower than that of the previous decadal rate of 19.51%. The sex ratio has improved from 913 (Census 2001) to 948 (provisional figures 2011) while the population density has increased to 347 from 303. The literacy rate of the district was 60.95% in 2001 which has increased to 70.92 in 2011 (Male: 77.89% and Female: 63.54%). In fact the literacy rate of the female population has increased at a rate higher (which was 50.78 previously) than that of the male population (which was 70.15 previously). The Dibrugarh district of Assam comprises of 7 administrative divisions. The administrative divisions are further subdivided into 7 nos. C.D. Blocks. There are 14 nos. police stations, 7 nos. revenue circle, 1362 villages (of which 1306 are inhabited 56 are uninhabited and 27 are forest villages) and 93 Gram Panchayats in the district. The geographical area of Dibrugarh district is 3381 sq. km. The total population of the district as per the provisional figures of 2011 census is 1327748 out of which 680114 are males and 647634 are females. However, the population density is higher than the previous census figures (393 and 351 respectively).
11 Mitra A., et. al (2008), Rural to Urban Migration: A District Level Analysis for India; IDE Discussion Paper. No. 137. 2008.3; available at http://hdl.handle.net/2344/729
12 Nath B.K., et.al. (2012), Undocumented Migration in the state of Assam in Northeast India estimates since 1971 to 2001, Asian Journal of Applied Sciences, Vol. 5 Issue 3, pp. 164-173.
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The decadal growth rate for the period 2001-11 is marginally lower than that of 1991-01 (12.04% and 13.68% respectively). The literacy rate of the district is 76.22% (Male: 82.59% and Female: 69.52%). In this district the literacy rate among the females show a higher rate of growth which was 59.95% among the females and 77.30% among the males. The overall pattern of population growth in Assam and the two districts of Tinsukia and Dibrugarh follow a polynomial trend. This is shown in the following Figures 3.16-3.1813 and Box 3.3 show the estimation of the polynomial curves for Assam as well as the two districts. Further the projected population has been shown in Table 3.13. The high value of the fitted polynomial curves indicates that about 99% of good fit for the population data in each case. The table projects that in the coming decade (2011-21), population growth of Tinsukia is forecasted to grow at 27% much higher than that of Dibrugarh district, although in the following two decades the growth pattern would be more or less same.
BOX 3.4: ESTIMATION OF THE EXPONENTIAL GROWTH CURVES
The exponential curve that is fitted is given by the following equation: where refers to the population at a given time-period t, and are constants which are to be estimated from the population data of the previous years. The in the following equations shows the goodness of the fitted curves. The estimated exponential curve for Assam is given by the following equation:
The estimated exponential curve for Tinsukia district is given by the following equation:
The estimated exponential curve for Dibrugarh district is given by the following equation:
13 In 1981, there was no census operation in Assam due to Assam agitation. The population figure for 1981 is being estimated from the polynomial curve that has been fitted for the overall data. This interpolated data has been used for further population projections by the three different methods.
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FIGURE 3-16: POLYNOMIAL POPULATION TREND IN ASSAM
FIGURE 3-17: POLYNOMIAL POPULATION TREND IN TINSUKIA DISTRICT
FIGURE 3-18: POLYNOMIAL POPULATION TREND IN DIBRUGARH, ASSAM
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TABLE 3-10: PROJECTED POPULATION OF ASSAM, TINSUKIA AND DIBRUGARH
Incremental Average Arithmetic Geometric Year Districts Increase growth rate Progression Progression Method of population 2021 Tinsukia 1367500 1796972 1390011 27.3% Dibrugarh 1434345 1619853 1444533 12.9% 2031 Tinsukia 1476219 2246215 1506233 13.9% Dibrugarh 1540943 1976220 1571507 12.7% 2041 Tinsukia 1584938 2807769 1622456 13.7%
3.3.3 Demographic Profile The study area for socio economic profiling was defined within block and surrounding areas based on the proposed location of exploratory and development wells and its proximity to the village and professional judgment. Of the study area defined, the baseline study focuses on forty nine villages within the block. This comprises of thirty six villages of Tinsukia district and thirteen villages of Dibrugarh district. The villages in Dibrugarh falls under Chabua, Panitola and Lahoal block whereas identified villages in Tinsukia falls under Guijan and Itakhuli block. The list of villages has been provided in the Table 3.11 below.
TABLE 3-11: LIST OF THE STUDY AREA VILLAGES IN THE KHAGARIJAN FIELD
District Villages Dibrugarh Ekoratoli Binoigutia, Baratichuk, Niz-Rahmoria, Rahmoria, Bagaritolia, Barahi-Da- Pathar, Chamoni Gaon, , Lukhurakhania, Nakoidhara, Chengdhora, Mukalbari T.E., Maijan, Thanai T.E., Thanaichuk, Dhopabor Gaon, Balijan Bangali, Raidang, Dadhia F.V., Bindhakota Gaon, Muluk Gaon, Udalguri T.E., Kharjan Grant, Boragadhoi Gaon, Maricha Gaon, Bamuni Hiloidhari, Naduwa T.E., Dinjoy Satra, Dinjoy Chapori, Dangar Chuk, Mudai Gaon, Jogipathar, Bogdungkinar, Baribongali, Mereli Pathar, Piporatoli, Miri Gaon. Tinsukia Guijan Gaon, Khamti Gohali 106 Nlr.Gt., Dinjan T.E. 106 Nlr, Nalani T.E. No-7 Wla., Nokhroy Te. 149/146(P)161/158,216/194/192 Nlr, Panitola Te.No-111 Nlr, Baghbari Gaon, Panitola Te.No-68 Fs.Gt., Nunpuria Kaivatra Gaon, Ukanimaria, Kachari Gaon, Kaptanchuk Gaon, Balijan T.E., Mahabirbari 765/348
The study area for socio economic assessment was defined as an area within 1-2 km radius around the 34 exploratory and development wells and is based primarily on reconnaissance surveys, census data information, toposheet maps, understanding of the project and professional judgment. The demographic profile in terms of total population, household size, sex-ratio of the selected villages in the block has been summarized in the sections below, while the detailed demographic profile of the study area villages has been provided in Annexure 3.18-3.21. However, the village level demography, literacy, work class and socioeconomic data of the
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2011 census is yet to be available so the sections below have been interpreted from the old data of 2001 Census.
Population and Household Size Balijan T.E (5124) has the highest population among the study area villages followed by Guijan Gaon (4685) and Thanai T.E. (4445). The lowest populations were recorded for Muluk Gaon with a total population of 100. The household size of the study area villages generally ranged within 4.32 to 6.67 with an average household size of 5.29.
Sex Ratio The average sex ratio of 950 recorded for the study area villages and is higher than the state averages of Assam (935).The highest sex ratio is recorded for Muluk Gaon (1173) followed by Barahi-Da-Pathar (1087) village. Of all the villages within the study area, 77% of the villages have a sex-ratio of more than 900 and the lowest sex-ratio was been recorded at Kaptanchuk Gaon (727). Scheduled Caste (SC) & Scheduled Tribes (ST)
The overall demographic data of study area villages shows only 7.59% of the population to be under ST category whereas 12.92% population belongs to scheduled caste category. The highest percentage of schedule tribe population was observed for Dadhia F.V (98.29%) whereas the highest population of schedule caste population was observed for Miri Gaon Village (82.52%).
Education & Literacy The study of the education and literacy profile in the region is relevant in order to have an understanding whether the proposed project can utilize skilled human resources available within the area. According to 2001 census data, the literacy rate in Tinsukia district is 63.21% which is lower than the state literacy rate of Assam. The average literacy rate of the study area observed as 56.15% which is below the state literacy rate (63.25%). The highest literacy rate was observed in Dinjoy Satra (87.40%) and the lowest in Nokhroy TE. 149/146(P) 161/158,216/194/192 Nlr (12.89%). Average male and female literacy rate in the study area was recorded at 65.33% and 46.39% which lower than the state average of 75.23 % and 51.85 % respectively.
Economic Activity & Livelihood Pattern The relevance of economic activity and livelihood pattern is important in the context of the study since depending on the existing situation one can predict the impact of the project activity on the economy of the region.
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The total working population in the study area villages varies from 11.00% to 61.45%. Of the total workforce, Chamoni Gaon revealed the highest percentage of workforce with 61.45% workers while Muluk Gaon revealed the lowest workforce percentage (11.00%). Major population in the study area villages are either workers in nearby Tea Estates or involved in agricultural crop cultivation as a source of their livelihood. Apart from the tea estates, the study area mainly comprises of mono cropped land with paddy being the major agricultural produce. Apart from paddy cultivation, inhabitants of study area villages are also involved in tea cultivation in their homestead land. The “Other worker” category contribute highest workforce category constituting about 75.21% of the study area population. Some fraction of the study area population is also reported working in Govt. and Private sector at Tinsukia and Dibrugarh.
3.3.4 Socioeconomic Infrastructure
Medical Facilities In Tinsukia district there are 3 sub divisional hospitals, 4 Primary Health Centers and 10 Community Health Center while in Dibrugarh there is one medical college and hospital in the town, 5 Community Health Centers, 6 Block PHCs, 10 SHCs, 9 State Dispensary and 230 sub-centers (of which 20 are medical units and 210 are family welfare units). However, there are no sub-divisional hospitals in the district. In the 11 villages of Tinsukia district considered for the study, only 3 villages have medical facilities within the villages. Primary Health centre is present only at Guijan Gaon. Of the remaining 8 villages, Baghbari Gaon has medical units at more than 10 kms from the village. The remaining villages have medical units within 10 kms. In the 38 villages of Dibrugarh district considered for the study, only 6 villages have medical facilities within the villages. Of the remaining 32 villages about 43% of the villages have medical units at more than 10 km distance from the village. Other villages have medical units within 10 kms distance. Of the study area villages, allopathic hospital is present only at Barahi-da-pathar village. Allopathic dispensary is present only in Baribongali and Nakoidhara village.
Educational Facilities The study area possesses necessary educational infrastructure to cater to the educational needs of the both rural and urban population. The overall educational institutional frame work of Tinsukia and Dibrugarh district is given Table 3.12 below. There are 1118 primary schools in Tinsukia which caters to 936 villages of the district. In Dibrugarh there are 1338 primary schools which take care of 1169 villages of the district. Comparatively, as the table indicates, Dibrugarh has better educational facilities in terms of more number of primary, secondary, middle level and higher secondary schools as well as colleges and technical institutions.
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TABLE 3-12: EDUCATIONAL FACILITIES OF TINSUKIA AND DIBRUGARH DISTRICTS
Educational Institution Tinsukia Dibrugarh Degree Collages 7 9 Technical Institution/Industrial School/Training School 1 2 Senior Secondary School 5 8 Secondary School 92 169 Middle Level School 264 397 Primary School 1118 1338 Source: Census Data 2001 Among the study area villages, 45 villages out of 49 identified villages have the provision of educational facilities. Primary schools are present in 45 villages among the identified villages for conducting socio economic studies. On the other hand, middle schools are present in 12 villages and senior secondary schools are present in 4 villages. However, in Naduwa TE village, primary school is present in more than 10km distance. However, there are no training/industrial schools within the study area villages.
Drinking Water facilities The Census data reveals that drinking water facility exits in all the villages. Tubewells are present in all of the study area villages whereas well is present in more than 32.65 % of study area villages.sz Transport & Communication Assam Trunk Road (AT Road) i.e. NH-37 is the major road connecting the study area with Dibrugarh and Tinsukia town and is being used by the local people as a route of transportation. Power Supply Electricity is available in all study area villages through a stable 220V electricity supply adequate for domestic, agricultural and other purposes.
Primary socio-economic study In addition to the collection and collation of secondary socio-economic data from census surveys primary level socio-economic information was obtained through discussion with village people. The summary findings of the consultations carried out have been discussed below: Majority of the people in the area are cultivators and paddy is the major agricultural produce. Apart from paddy cultivation, household tea cultivation is also common. Many people also work at the local tea estates; few are engaged in public and private organizations in the urban areas of Dibrugarh, Chabua, Panitola, Tinsukia etc.
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Majority of the houses in the rural and urban areas have electrical connections. However frequent power failures were reported by the locals during the consultation. Water requirement is catered through household borewell/tube well facility in the village areas. It was reported during consultations that all parents send their children to the primary school. Almost every village has a primary school; however, percentage of students pursuing higher education is comparatively less. During the public consultations the household members expressed their concern about the health facilities. Primary health centers and health centers run by the tea estates are present within the Field. The serious patients were taken to hospitals at Dibrugarh and Tinsukia. The local communities at the tea garden mentioned about the facilities they receive from the tea estates like hospitals and ambulance services, incentives during marriages for the family members and other infrastructure like utensils etc, subsidized LPG for cooking. The villages located close to the Brahmaputra and Dibru River reported that flood water from Brahmaputra and Dibru inundates the village areas; however, the flood water was reported to recede within 6-7 days. The villagers also reported that leopards are frequently observed at the tea gardens; elephants, deer, wild buffalo migrates from the Dibru-Saikhowa national park to settlements close to Dinjan TE, Balijan TE etc. It was also reported by the villagers that OIL has been operating in the Block for several years. Site demarcation and procurement of land for drilling activities were reported from several villages within the Field (Nunpuria Jadavgaon, Dighalipathar, Dinjan TE colony, Baijan TE Colony etc.). Drilling activities by OIL were reported by the villagers Nimbari, Jeraipathar, Barbari Bangaligaon, Hathigondai, Genickuk, Rahmoria, Kanjikhua etc. Hydrocarbon production activities by OIL were reported by the Balijan North T. E colony members.
Village wise details of public discussion have been provided at Annex 3.22.
3.4 CULTURAL AND HISTORICAL SITES There are no designated archaeological sites within Tinsukia and Dibrugarh districts14. As is typical of rural India settlements, each village in the Field has some cultural sites or sites of religious significance, like temples, mosques, graveyards etc. Some of them are of significance for the community. Sometimes their significance is related during specific seasons/or time of the year.
14 Source: Archeological Survey of India website http://asi.nic.in
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Photo 3.20: Discussion with villagers of Thanai TE Photo 3.21: Discussion with villagers at Nunpuria Colony Jadavgaon
Photo 3.22: Discussion with villagers at Jeraipathar Photo 3.23: Discussion with villagers at Balijan North Tea Estate
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4 Environmental Impact Assessment
The impact assessment section of the EIA study systematically identifies, characterizes and evaluates the potential impacts arising out of the project and prioritizes them through a semi- quantitative system so that they can be effectively addressed by Environment Management Plans. Potential environmental impacts may arise out of various sequential activities (as discussed in section 2.6 of this report) to be undertaken as part of proposed project.
4.1 IMPACT ASSESSMENT METHODOLOGY An environmental impact identification matrix has been developed to present an overview of possible interactions between project aspects and components of the environment which may get affected. The matrix structure takes into account physical, biological and socioeconomic components of the environment on one axis (X axis) and activities / aspects of the proposed drilling project on the other side (Y axis). Aspects (based on phases of activities like pre- drilling activities, drilling, decommissioning and potential accidental events) and impacts on environmental components that have been taken into consideration were in line with standard environment management system terminology. Environmental and socioeconomic components were identified based on reviewing of applicable legislation and baseline environment, site reconnaissance visits, discussions with stakeholders and SENES’ professional judgment. Potential environmental and socio-economic impacts that may result from any of the identified project aspects has been identified in a matrix based on activity-component interaction and has subsequently been used to develop an impact evaluation matrix that list evaluation scores based on significance criteria delineated in Section 4.1.2.
4.1.1 Impact Criteria and Ranking Once all project environmental aspects were comprehensively identified for the different activities of the project, the level of impact that may result from each of the activity- component interactions has been assessed based on subjective criteria. For this, three key elements have been taken into consideration based on standard environmental assessment methodologies: Severity of Impact: Degree of damage that may be caused to the environmental components concerned; Extent of Impact : Geographical spread of impact around project location and corridors of activities; and Duration of Impact: Time for which impact lasts taking project lifecycle into account.
These elements have been ranked in three levels viz. 1 (low), 2 (moderate) and 3 (high) based on the following criteria provided in Table 4.1 below:
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Table 4-1: Impact Prediction Criteria Impact Criteria Ranking Elements Severity Regional impact resulting in long term and/ or medium damage to 3 the natural environment. Major impact on community and occupational health (e.g. serious injury, loss of life) on account of accidental events viz. well blow- outs and related operational activities. Adverse national media attention. Local scale impact resulting in short term change and / or damage to 2 the natural environment. Temporary loss of land, livelihood source of affected communities Local scale impact on terrestrial habitat, endangered species, drainage pattern and community resources. Moderate impact on occupation and community health & well being (e.g. noise, light, odour, dust, injuries to individuals) Complaints from the public, authorities and possible local media attention. Limited local scale impact causing temporary loss of some species 1 etc Limited impact on human health and well-being (e.g. occasional dust, odour, light, and traffic noise). Public Perception/Concern Extent Regional scale impact and including impacts to physical, biological 3 and socio-economic environment of the Khagarijan Field Largely local level impact limited to immediate vicinity of the 2 proposed well sites Impact not discernible on a local scale 1
Duration The impact is likely to occur during the entire project life cycle at 3 all times. The impact is likely to occur in some phases of project life under 2 normal operating conditions. The impact is very unlikely to occur at all during project life cycle 1 but may occur in exceptional circumstances.
A positive or beneficial impact that may result from this project has not been ranked and has been depicted in the form of ++.
4.1.2 Impact Significance The significance of impact has been adjudged based on a multiplicative factor of three element rankings. The Table 4.2 (below) depicts impact significance in a scale of LOW- MEDIUM-HIGH and will be used for delineation of preventive actions, if any, and management plans for mitigation of impacts. Impact significance has been determined taking into account measures which have been factored in the design and planning phase of the project. Legal issues have been taken into
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TABLE 4-2: CRITERIA BASED SIGNIFICANCE OF IMPACTS
Extent of Impact Impact Significance Severity of Impact (A) Duration of Impact I (B) (A X B X C) 1 1 1 1 1 1 2 2 1 2 1 2 Low 1 1 2 2 2 1 2 4 1 2 2 4 3 1 2 6 Medium 1 3 2 6
2 2 2 8 3 2 2 12 2 3 2 12 2 2 3 12 3 3 2 18 High 3 2 3 18 2 3 3 18 3 3 3 27 - Beneficial Impact - ++ Positive
To assist in determining and presenting significance of an impact, an impact evaluation matrix (Table 4.3) has been developed based on the one developed for the impact identification exercise. In addition to ranked weights, significance of impacts has been depicted using colour codes for easy understanding. In case an environmental component be impacted by more than one project activity, higher impact significance ranking has been taken as the significance ranking for subject receptor. Impacts that have been determined to be having high significance ranking of “>12” are considered significant and hence require examination in terms of preventive actions and/or additional mitigation to reduce level of the potential impact. Recommended additional mitigation measures and management plans are presented in Chapter 6. A second evaluation matrix presents significance of impacts after considering that proposed mitigation measures will be implemented (Table 4.8). The identified impacts are further discussed in detail in the following section with discussion focusing on impacts of higher significance. This is followed by a point wise outline of mitigation measures recommended.
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Table 4-3: Impact Identification Matrix
Environment Physical Environment Biological Environment Socio-economic Environment
icOpportunity
raffic
Activity
Habitat uatic
Aesthetics &Visuals Aesthetics AirQuality NoiseQuality & T Transport Use Land SoilQuality Habitat & Flora Floral Habitat Wildlife Fauna &Endangered Threatened species &rout corridor Migratory Aq &Fauna Flora Aquatic Livelihood of Loss opportunity Job on Conflict Infrastructure of Disruption Resources Property Common Discomfort &Noise Dust Agricultural of Loss Productivity Population of Influx Site & Heritage Cultural Econom & Job &Safety Health Occupational Safety & Health Community Local Local Physiography Drainage & Resources Water Surface quality water Surface Ground Resources Water Groundquality water A. Pre-Drilling Activities Site selection and land acquisition x x x Site clearance and top soil removal x x x x x x x x x x + x Well site & access road construction x x x x x x + x x Sourcing & transportation of borrow material etc x x x x x x x x x x x + x x Storage and handling of construction debris x x x Transportation of drilling rig and ancillaries x x x x x x x x
Operation of DG set x x Workforce engagement & accommodation at construction site x x x + x Consumption of water for construction & domestic use for labourer x x Generation of domestic solid waste & disposal x x x x x x Generation of waste water & discharge from construction activity & labour camp x x x Surface run-off from construction site x x x x x x B. Drilling & Testing Physical Presence of drill site x x Operation of DG sets and machinery x x x x Operation of drilling rig x x x x x Storage and disposal of drill cuttings and mud x x x x Generation of process waste water & discharge x x x Surface run-off from drill site x x x x Generation of domestic waste water & discharge x x x x Generation of Municipal waste & disposal x x x x Workforce engagement & accommodation at drill site x x x + x Flaring during production testing and process upset x x x x Accidental events – blow out x x x x x x x x x x x x Accidental events-spillage of chemical & oil x x x C. Decommissioning and Reinstatement Dismantling of rig and associated facilities x x x x Transportation of drilling rig and ancillaries x x x x Removal of well site construction materials & disposal x x x
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4.2 IMPACT ASSESSMENT This section discusses the impacts of the project activities on the environmental receptors that stand to get affected adversely by the project. It discusses probable impacts during various phases of the project lifecycle on the environmental and socioeconomic components. Rankings for every activity – component interaction is based on the criterion set earlier and resulting environmental significance with necessary justification that has been recorded below for every set of impacts and the same has been represented in evaluation matrices. In broader context, it is however important to remember that operations related to drilling, testing and completion activities also include positive socioeconomic impacts in terms of increase in local business opportunities and on a larger perspective, by providing potential energy security at a national level.
4.2.1 Visual Impacts & Aesthetics Khagarijan Field is an operating field, where exploration and production of hydrocarbon was being undertaken for several years. In this hydrocarbon field, drilling is an activity about which people are aware. Visual impacts during proposed drilling operations is anticipated from site clearance and well site preparation, vehicles involved in transportation of raw materials and personnel, material stockpiles and physical presence and operation of drilling rig and associated facilities. During drilling site preparation nearly 2.2 ha land will be cleared for construction of drill site. Vegetation clearance will be required for 15 drill sites located in tea garden, 2 well sites located in household tea gardens and 1 well located in forest land. Again during site construction activity, dust will be generated from transport of construction material, machinery and personnel, haphazard dumping of construction waste, domestic waste from labour camp may cause visual and aesthetic impacts. Such impacts likely to be particularly experienced by communities residing in villages located in the vicinity (viz. settlements of Dighalipathar, Hathigonda, Orangpati, Balijan Pani Era, Rahmoria, Genichuk, Nimbari, Balijan North TE colony, Jariguri, Panitola TE Colony, Captain Chawk etc.) of proposed wells. However taking into account the temporary nature of site preparatory activities and necessary mitigation measures to be implemented by the proponent with respect to the siting of well locations (borrow areas, use of existing infrastructure etc.) the impact is not considered to be of major significance. Visual impact due to the operation of drilling rig and presence of base camp is not considered major given the temporary nature of exploratory and development activities (about 90 days) provided the well is not indicative of any commercial hydrocarbon reserve. Also with drilling waste and process waste water is likely to be temporary stored in impervious pits no visual impact to this regard is envisaged. Some visual impacts are also envisaged from light generated from flaring events and would be particularly experienced by people residing close to the proposed well sites (settlements mentioned at the earlier paragraph). However, such activity is likely to be of intermittent in nature, to occur only during process upset and
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Mitigation Measures All the construction activity will be restricted within the designated site; Dust nuisance from construction site will be suppressed through periodical water spraying at disturbance area; On completion of work all temporary structures, surplus materials and wastes will be completely removed; Domestic solid wastes temporarily stored in the collection point within the well site camps will be transported to designated solid waste disposal sites at Tinsukia or Dibrugarh at regular intervals; After decommissioning of rig and associated facilities, drill platform will be removed, pits & garland drains will be filled up, construction material will be removed & disposed and drill sites will be restored; Site will be rehabilitated through laying of top soil.
4.2.2 Impacts on Air Quality
Operation of vehicles and construction machinery Exhaust emission from operation of construction machinery is likely to contribute to air pollutant load (primarily particulate matter, NO2, SO2 etc.) in the ambient air near well site facilities. However, considering localized nature of impacts, temporary nature of construction along with necessary mitigation measures likely to be adopted by the proponent (viz. pollution checking of vehicles etc.) the impact is considered to be of low significance. Severity of Impact 1 Extent of Impact 2 Duration of Impact 2 Impact Significance = 4 i.e. Low
Construction material transport, storage and handling During construction phase it is estimated that about 500 m3 of borrow material and 1000 m3 of aggregates will be required for construction of 1 well site , road construction/strengthening and other site preparatory activities. Fugitive emission is therefore anticipated from transportation, storage and handling of construction material by contractor personnel. Generation of such fugitive dust is likely to be governed by micro-meteorological conditions (wind speed and direction) and transportation route condition (degraded in patches). However, the construction activity, rig mobilization and decommissioning activity is temporary and limited movement of project vehicles and adopting specific mitigation
SENES/K-20197/ November 2013 119 Oil India Ltd. Pre Drill EIA for Drilling of 30 wells at Khagarijan Field measures (viz. spraying of water, management of vehicle loadings etc.) no significant impact is therefore envisaged. Severity of Impact 2 Extent of Impact 2 Duration of Impact 1 Impact Significance = 4 i.e. Low
Operation of Diesel Generator (DG) Sets The proposed project will involve the operation of diesel driven 1000KW generators for drilling of each well; additionally 200 KW generators will be required to meet power demand of camp and other emergency requirements. The operation of DG sets will result in the generation of air pollutants viz. PM, NO2, and HC thereby affecting the ambient air quality. The dispersion of these air pollutants may affect the receptors viz. village settlements located in near vicinity of the well sites. However, considering the temporary nature of drilling phase (approx 90 days), wet and humid conditions prevalent in the region and provision of adequate DG set stack height for effective dispersion of air pollutants, no significant impact to this regard is envisaged. Additionally the proponent also plans to adopt and implement necessary mitigation measures as discussed in the subsequent sections to effectively address potential air quality impacts from DG set operation. In order to predict the Ground Level Concentrations (GLCs) at various distances from the source of the above mentioned pollutants, an air modeling exercise has been undertaken and is discussed in the impact prediction section below. The following input parameters (Refer Table 4.4) have been considered in the impact prediction modeling undertaken using Industrial Source Model (ISC 3). Table 4-4: Input Parameters Considered for Monitoring
Stack Stack gas Emission Rate Emission Stack Stack gas Diameter velocity (g/sec) Source Height (m) temp (K) (m/s) (m) PM NO2 HC 1250 KVA DG 7 0.30 749.4 25.0 0.007 1.836 0.004 250 KVA DG 3 0.30 708.7 25.0 0.003 0.188 0.008 Flare Stack 9 0.5 1273 20.0 - 0.149 -
Though, ISC3 is a refined model, the model run was carried out based on micro- meteorology to predict air quality impacts for an average 24 hr period that may be caused by peak power utilization at the drill site. The model was run considering operation of both 1000 KW (~1250 KVA) & 200 KW (~250 KVA) DG set. To predict the incremental concentrations of the pollutants due to the proposed operation of DG sets for drilling and the concentration values for these pollutants (viz. PM, NO2, and HC) estimated during the baseline monitoring was also taken into account (Refer Table 4.5).
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TABLE 4-5: PREDICTED GROUND LEVEL CONCENTRATIONS FOR AIR POLLUTANTS
Predicted GLC at Bharalua (μg/m3) Predicted Maximum GLC (μg/m3) Baseline Distance Pollutants Incremental Predicted Incremental from Well Direction Concentration at GLC Concentration Bharalua (m) 1250 & 250 KVA DG Set NO 2 2.998 15.44 18.438 30.994 2831 SE (μg/m3) PM SE 0.017 47.38 47.397 0.167 2549 (μg/m3) HC SE 0.023 3.17 3.193 0.221 2549 (μg/m3)
FLARING OF GASES NO 2 0.052 15.44 15.492 0.799 3397 SE μg/m3)
For spatial mapping of pollutants, the GLCs revealing worst case scenarios were superimposed on land use (5km x 5 km area) abutting Well 20. The baseline air pollutant concentration of AQ Bharalua was considered while determining predicted GLCs. The incremental Ground Level Concentration (GLCs) of the pollutants (as discussed above), do not exhibit any appreciable decrease in air quality. The predicted levels of the pollutants did not reveal significant impacts on the ambient air quality due to operation of DG set. Severity of Impact 1 Extent of Impact 2 Duration of Impact 2 Impact Significance = 4 i.e. Low
Flaring of gases Flaring provides means of safe disposal of vapor streams from its facilities; by burning them under controlled conditions such that adjacent equipment or personnel are not exposed to hazards. With combustion gas products depending on feed gas composition, the flaring of gases may lead to the generation of NOx. These pollutants emitted may therefore contribute to air pollutant load of the ambient air thereby affecting well site receptors nearby viz. village settlements, schools etc. Further considering most of the wells located in proximity to settlements, intermittent nature of flaring operation only during process upset, related design considerations with respect to fuel-air mixture, and OIL’s conformance with CPCB Flaring Guidelines, the impact is envisaged to be of low significance. Severity of Impact 2 Extent of Impact 2 Duration of Impact 1 Impact Significance = 4 i.e. Low
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The isopleths generated for various pollutants due to operation of DG sets and flaring superimposed on 5km X 5 km land use surrounding Well 20 has been provided in Figures 4.1 to 4.4.
FIGURE 4-1: PREDICTED NO2 CONCENTRATION PLOT (1250 & 250 KVA DG SET)
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FIGURE 4-2: PREDICTED PM CONCENTRATION PLOT (1250 & 250 KVA DG SET)
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FIGURE 4-3: PREDICTED HC CONCENTRATION PLOT (1250 & 250 KVA DG SET)
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FIGURE 4-4: PREDICTED NO2 CONCENTRATION PLOT (FLARING)
Mitigation Measures: All vehicles used for transportation of loose and friable materials will not be loaded over the freeboard limit and will be covered. Water spraying will be done on the approach roads to control re-entrained dust during dry season; Equipment, machinery and vehicles having inbuilt pollution control devices will be considered as a measure for prevention of air pollution at source
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Engines and exhaust systems of all vehicles and equipment used for the project will be maintained so that exhaust emissions are low and do not breach statutory limits set for that vehicle/equipment type. DG set will appropriate stack height will be utilized. Personnel Protective Equipments (PPEs) like mask, gloves, eye gears will be provided to workers at site.
4.2.3 Impact on Noise Quality Potential impact on noise quality is anticipated from vehicular movement, operation of construction machinery, access road strengthening during well site preparation and operation of drilling rig and ancillary equipments during drilling operation. Operation of construction machinery/equipments Operation of heavy machinery/equipments and vehicular movement during site preparatory and road strengthening/construction activities may result in the generation of increased noise levels as specified in the Table 4.6. The same can be used as a reference for calculating probable noise pressure levels arising out of a number of such equipments. Table 4-6: Construction Equipment Noise Levels Sound Level At Operator (in decibels) Equipment Average Range A. Earth Moving Equipment Front End Loader 88.0 85-91 Back Hoe 86.5 79-89 Bull Dozer 96.0 89-103 Roller 90.0 79-93 Truck 96.0 89-103 B. Material Handling Equipment Concrete Mixer <85.0 - Crane/Hydra <85.0 - Derrick 100 97-102
Source: British Columbia, “Construction Noise,” Workers Compensation Board of BC
The noise related disturbance is likely to be experienced by communities residing in proximity of the construction site and along material transportation routes. The environmental setting of well sites reveals that settlements are close to the proposed well site and site access road. The settlements located very close to the proposed wells (within 100 m of Wells 2, 3, 6, 8, 11, 13, 14, 18, 23, 26, 27 and 29 etc.) could face disturbance due to the proposed construction activities. Considering the construction phase activities to be of temporary nature, limited daily movement of project vehicles (3-4 nos. vehicle for transportation of
SENES/K-20197/ November 2013 126 Oil India Ltd. Pre Drill EIA for Drilling of 30 wells at Khagarijan Field personnel and 8-10 nos. for material transport) and adequate mitigation measures (viz. equipment maintenance, restriction of work during nighttime etc) to be implemented by the project proponent, impact is considered to be of medium significance.
Severity of Impact 2 Extent of Impact 2 Duration of Impact 2 Impact Significance = 8 I.E. Medium
Operation of drilling rig Operational phase noise impacts are anticipated from operation of drilling rig and ancillary equipment viz. shale shakers, mud pumps and diesel generators. Studies indicated that noise generated from operation of drilling rig generally varies in the range of 88-103 dB(A). Other contributors of high noise level at the well site include shale shakers, mud pumps and diesel generators. The average equivalent noise levels of drilling rig and ancillary equipment has been provided in the Table 4.7 for reference. Table 4-7: Drilling Rig & Equipment Noise Levels15 Equivalent noise levels in dB(A) Equipment Average Range Drilling Rig 96.9 88.0-103.0 Mud Pumps 76.9 73.3 -80.5 Diesel Generators 72.7 71.8-73.7 Shale Shakers 76.6 -
Further, considering drilling to be a continuous operation, noise generated from aforesaid equipments has the potential to cause discomfort to the local communities residing in proximity (within 250m) of the rig facility. All drill sites, except Wells 1,10, 12, 16, 19, 20, 21, 24 and 25 have settlements within 250m of the site, so settlements located close to majority of the wells will face discomfort due to drilling operation. Occupational health and safety impacts viz. Noise Induced Hearing Loss (NIHL) is also anticipated on personnel working close to such noise generating equipment. However, drilling activities will be undertaken for short duration (approx 45 days for drilling phase) and necessary noise prevention and control measures viz. use of acoustic barriers, provisions for proper PPEs, regular preventive maintenance of equipments etc. will be implemented by the-proponent to reduce the noise impact on the communities residing in proximity to the well sites.
15 “Noise Report on Drilling Operation” – British Drilling & Freezing Ltd – Prepared by K A Worthington; AEC Report: P852-2; 17th October 2002;
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Noise Level Prediction A noise modeling exercise was undertaken based on standard noise attenuation equations to predict noise levels from drilling rig (and ancillary equipments) near sensitive receptors within 200m in presence of a noise barrier (refer Annex 4.1). A noise attenuation plot has been developed considering natural attenuation by distance with noise level predictions. The noise generated from drilling rig is considered to be about 95.0 dB (A) at a distance of 10m from the rig location. Noise attenuation equations (without any noise barrier) show that the normal attenuated noise at any receptor points located at a distance of about 100 m and 200 m from the fence-line of the rig, will be in the range of about 75.0 dB(A) and 68.9 dB(A) respectively. In the absence of an acoustic barrier, the predicted noise levels were found to exceed the day time noise standard of i.e. 55 dB (A). However, with the introduction of a noise barrier (5 m in height) at the fence-line will be enough to decrease noise levels near sensitive receptors at 200m to about 56.9 dB (A). However a detailed noise modelling exercise to look at option of noise reductions will be conducted at the design stage to determine the barrier specifications. The noise attenuation plot with and without acoustic barrier is presented in Figure 4.5.
FIGURE 4-5: NOISE ATTENUATION PLOT FOR DRILLING PHASE
Severity of Impact 2 Extent of Impact 2 Duration of Impact 2 Impact Significance = 8 i.e. Medium
Mitigation Measures: Typical mitigation measures for noise will include the following:
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Installation of sufficient engineering control on equipment and machinery (like mufflers & noise enclosures for DG sets and PC pumps) to reduce noise and vibration emission levels at source, carrying out proper maintenance and subjecting them to rigid noise and vibration control procedures. Re-locating noise sources distantly from the sensitive receptors (viz. settlements, schools etc.) to take advantage of distance and shielding Providing noise barrier at the fence line of the well site facing the sensitive receptors Providing Personnel Protective Equipments (PPEs) like ear plugs/muffs to workers at site. Undertaking preventive maintenance of vehicles to reduce noise levels.
4.2.4 Potential Impact Transport and Traffic Access roads to the drill sites (i.e. PWD road, village road, tea garden roads) are not busy vehicular route. The traffic survey data shows that 459 nos. (52 heavy vehicles) recorded at Chabua-Rohmaria Road at Chetiagaon and 493 nos. (75 heavy vehicles) vehicles recorded on Tinsukia-Guijan Road near Borguri. However, only few private vehicles and two wheelers ply at the internal village roads. 100 trailer/truck load material will be transported during site construction and decommissioning phase to each drill sites. In the transport route, there are number of schools. Disturbance to traffic movement during school time is therefore anticipated from additional traffic during school hour. With respect to increase in traffic movement the impact is considered to be of medium significance.
Severity of Impact 2 Extent of Impact 2 Duration of Impact 2 Impact Significance = 8 i.e. Medium
4.2.5 Potential Impact on Land Use To construct drill site, approximately 2.2 ha land (agricultural land/ tea garden land/ forest land) per well site will be required. OIL will purchase all these private land from the land owners. After drilling operation, the site would be restored and reinstated.
Severity of Impact 2 Extent of Impact 2 Duration of Impact 3 Impact Significance = 8 i.e. Medium
4.2.6 Impact on Soil Quality Potential impact on soil quality is envisaged in the form of increase in soil erosion and loss of soil fertility resulting site clearance and top soil stripping during well site preparation and accidental spillage resulting from storage and handling of mud chemicals. Soil quality impacts so identified have been assessed and evaluated in the section below.
Site clearance and stripping of top soil As discussed in the baseline section 3.1.9, the soil of Khagarijan Field is characterized by fertile alluvial soil thereby contributing to the agricultural productivity of the region and also
SENES/K-20197/ November 2013 129 Oil India Ltd. Pre Drill EIA for Drilling of 30 wells at Khagarijan Field large scale tea plantation. Stripping of top soil is therefore likely to affect the soil fertility of the well sites. It is estimated that about 3300 m3 of top soil will be removed per well site having an area of 2.2 ha considering 15 cm top soil. However, such impact is considered to be temporary taking into account the fact the proper reinstatement of site will be undertaken by the proponent in case the wells are not indicative of any commercially exploitable hydrocarbon reserves. Necessary surface run-off control measures will be adopted by the proponent during construction phase to prevent contamination of abutting agricultural land from discharge of surface run-off characterized by increased sediment load. Further specific mitigation measures will be implemented by the proponent to stabilize the top soil to preserve their fertility characteristics during site restoration. The impact is therefore considered to be of medium significance.
Severity of Impact 2 Extent of Impact 2 Duration of Impact 2 Impact Significance = 8 i.e. Medium
Sourcing of borrow material Site preparatory activities will involve the sourcing of earth-fill from borrow areas. Such sourcing activity may lead to direct and indirect long-term major adverse impacts on the environment due to loss of productive top soil if located on agricultural land/tea garden. The loss of top soil may also enhance the soil erosion potential of the area resulting in increased sediment load in surface run-off. Since most of the construction materials would be available from existing quarries nearby, relatively few new borrow areas will be required. Considering above scenario the impact is considered to be of low significance. Severity of Impact 1 Extent of Impact 2 Duration of Impact 2 Impact Significance = 4 i.e. Low
Storage and disposal of drill cuttings and drilling mud 3 3 It is estimated that nearly about 290 m of drill cuttings and 6.2 m /day of drilling wastewater and 5 m3/day waste mud are likely to be generated from each well during drilling operation. Improper storage and disposal of such process waste on open soil or unlined areas may therefore lead to the contamination of soil onsite and abutting land if not properly managed. With the project design planning taking into account construction of HDPE lined impervious pits of capacity 800 m3 each for temporary storage of drill cuttings and 3200 m3 drilling fluid respectively and their disposal in accordance with “CPCB Oil & Extraction Industry Standard – Guidelines for Disposal of Solid Wastes” no significant impact to this regard is envisaged. Further with the proponent catering to the use of water based mud the drill cuttings and waste drilling mud generated are likely to be non-hazardous in nature (however, will be tested to establish its nature) and is not anticipated to pose any potential threat to the soil environment. The impact is therefore considered to be of low significance.
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Severity of Impact 2 Extent of Impact 2 Duration of Impact 1 Impact Significance = 4 i.e. Low
Storage and handling of fuel and chemicals Contamination of soil can result from the project activities if certain operations like storage of chemicals and fuels, spent oil and lubricants are not managed efficiently. Storage of chemicals and fuels, spent lubricants on unpaved surfaces have potential for contamination of soil. Accidentally, if chemicals, oil and lubricants are spilled, either during transportation or handling, on open soil may contribute to soil contamination. However, considering that appropriate spill prevention and control measures to be implemented (refer below) by the proponent the impact is considered to be of low significance.
Severity of Impact 2 Extent of Impact 2 Duration of Impact 1 Impact Significance = 4 i.e. Low
Mitigation Measures: The following mitigation measures are proposed for reducing impact on soil quality: Restricted project and related activities during monsoon season; Carrying out adequate restoration of soil, to the extent possible; Implementing adequate sediment control measures to prevent discharge of untreated surface run-off characterized by increased sediment load to abutting agricultural land. Ensuring proper storage of drill cutting (in impervious HDPE lined pits) and chemicals (paved and bunded areas) to prevent any potential contamination from spillage. Implementing appropriate spill prevention and control measures. Provision of an oil-water separator at the storm water drainage outlet to prevent discharge of contaminated run-off.
4.2.7 Impact on Topography & Drainage
Potential impact on drainage and topography viz. alteration of drainage pattern, water logging etc. are anticipated during well site preparation, widening/strengthening of access roads and restoration of well facilities. The impact details have been discussed below:
Site preparation and road construction/strengthening
Potential impact on drainage is primarily anticipated in the form of disruption of natural drainage pattern during site preparation and approach road construction. Since site preparation involves rising of acquired land to about 1 m from the ground level it may lead to alteration of onsite micro-drainage pattern leading to potential problems of water logging in
SENES/K-20197/ November 2013 131 Oil India Ltd. Pre Drill EIA for Drilling of 30 wells at Khagarijan Field the agricultural land and settlements abutting the drill site. This problem is likely to be further aggravated due to heavy rainfall experienced by Tinsukia and Dibrugarh district throughout the year (Refer section 3.1.2). The infrastructure in major portion of the Khagarijan Field is characterized by paved and unpaved rural roads which are adversely affected during intense rainfall received by the area. Well specific environmental setting study shows that all the wells are located closed to existing road. Site approach to be constructed for drill site varies to 50-60 m. However, widening of existing road will be required for effective transportation of drilling rig and heavy equipments to the well site. Widening/ new construction of roads could therefore result in the alteration of drainage along water crossings and may lead to water-logging of adjacent lands and settlements if not properly managed. However, OIL will provide cross drainage structures viz. culverts etc. at road embankments and stream crossings to ensure uninterrupted drainage near the well site or approach road. Severity of Impact 2 Extent of Impact 2 Duration of Impact 2 Impact Significance = 8 i.e. Medium
Well site restoration Site restoration will be initiated for well site not indicative of any commercially exploitable hydrocarbon reserves. Unplanned restoration may lead to the long term disruption in natural drainage pattern and water logging in neighbouring agricultural land abutting the site. However, adequate care will be taken by the proponent to restore the site back to its original condition based on the originally existing contours and predominant slope to prevent any such adverse drainage impacts. The impact is considered to be of medium significance with onsite drainage being dependent on the proper site restoration. Severity of Impact 2 Extent of Impact 2 Duration of Impact 2 Impact Significance = 8 i.e. Medium
Mitigation Measure Leveling and grading operations will be undertaken with minimal disturbance to the existing contour, thereby maintaining the general slope of site; Disruption/alteration of micro-watershed drainage pattern will be minimized to the extent possible. Loss of micro-watershed drainage, if any, is to be compensated through provision of alternate drainage.
4.2.8 Impact on Surface Water Quality Impact on surface water quality of natural drainage channels and community water bodies may arise from discharge of contaminated surface run-off, sewage and process waste water generated during various phases of the proposed project.
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Surface run-off discharge As discussed under section 4.2.4, site clearance and stripping of top soil during site construction will result in an increase in soil erosion potential leading to an increased sediment load in the surface run-off during monsoon. Also, surface run off from drilling waste (cuttings and drilling mud), hazardous waste (waste oil, used oil etc) and chemical storage areas may lead to the pollution of receiving water bodies viz. natural drainage channels, ponds etc. This situation is likely to be more pronounced considering rainfall records of Tinsukia and Dibrugarh districts (Refer section 3.1.2). However, taking into account the provision of onsite drainage system and sediment control measures, discharging of surface run off in compliance with the CPCB Inland Water Discharge Standards, the impact is considered to be of medium significance. Severity of Impact 2 Extent of Impact 2 Duration of Impact 2 Impact Significance = 8 i.e. Medium
Discharge of drilling mud and process wash water It is estimated that nearly about 5 m3/day of drilling mud and 6.2 m3/day process wastewater is likely to be generated during drilling operation. The drilling waste so generated may be characterized by the presence of oil & grease, barites and heavy metal which on discharge to nearby natural drainage channels and/or rivers may lead to possible surface water contamination. However, considering usage of water based mud for the proposed project, temporarily storage of drilling waste in an HDPE lined pit to ensure conformance with CPCB Industry Specific Standards for Oil Drilling & Gas Extraction Industry and guidelines provided by the MoEF under the Hazardous Wastes (Management, Handling & Transboundary Movement) Rules, 2008 the impact is considered to be of low significance. Severity of Impact 2 Extent of Impact 2 Duration of Impact 1 Impact Significance = 4 i.e. Low
Mitigation Measures Following mitigation measures will be implemented for surface water pollution control: Proper treatment of all wastewater and produced water and any water discharge from well site to should comply with CPCB Inland Water Discharge Standards for Oil and Gas Industries Drainage and sediment control systems at the well site will be efficiently designed Construction activities viz. stripping, excavation etc during monsoon season will be restricted to the extent possible. All chemical and fuel storage areas, process areas will have proper bunds so that contaminated run-off cannot escape into the storm-water drainage system.
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An oil-water separator will be provided at the storm water drainage outlet, to prevent discharge of contaminated run-off.
4.2.9 Impact on Hydrogeology & Ground Water Quality Potential impacts on groundwater resources that could arise as a result of the proposed drilling activities include the following:
Ground water extraction Water to meet domestic requirement of operational workforce, drilling mud preparation and flushing of holes will be sourced through bore wells within the drill site. It is estimated that on average 40m3/d of water will be required per well for preparation of drilling mud and cater to domestic requirements. Taking into account drilling to be a temporary activity (approx 90 days) and both Tinsukia and Dibrugarh being designated as “safe” for groundwater extraction by the Central Ground Water Authority impact on ground water resource is considered to be low.
Severity of Impact 2 Extent of Impact 2 Duration of Impact 1 Impact Significance = 4 i.e. Low
Drilling, storage of drill cuttings and waste drilling mud Possibility of contamination of subsurface and unconfined aquifers may exist if the casing and cementing of the well is not carried out properly leading to infiltration or seeping of drilling chemicals or mud into porous aquifer region. The same is also valid for disposal of drilling waste and mud in an open/unpaved pit. However, with the project proponent catering to the use of water based mud and storage of drill cuttings and waste drilling mud in an HDPE lined pit, impact is considered to be of low significance. Severity of Impact 2 Extent of Impact 2 Duration of Impact 1 Impact Significance = 4 i.e. Low
Mitigation Measures Proper engineering controls will be used for drilling and cementing operations Water based, non hazardous type of drilling mud will be utilized for drilling operation Drill cuttings & mud will be stored in HDPE lined pits
4.2.10 Impact on Biological Environment The potential impacts on ecological habitat of the Khagarijan Field due to proposed drilling operations are discussed below:
Loss of flora and floral habitat
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Some wells (12 wells) are located on agricultural land where there are no prominent vegetation except seasonal crops and herbs. However, 15 wells are located in the plantation areas of tea garden and 2 wells are located in household tea garden areas where only tea bushes and shed trees are recorded. Out of 30 wells, one well is located in a forest area, where few vegetation cover is recorded. Vegetation clearance in an area of 2.2 ha will be required for wells located in the tea garden and forest land for construction of drill site. The clearance of vegetation in the forest land will be undertaken after taking necessary Forest Clearance from the Forest Department. Reviewing of ecological conditions of the Kharagijan Field reveals no flora or floral assemblages that are unique to the sites or are listed as protected or threatened plant species. Taking drilling activity into account, drill site will be restored to near original condition and its impact on flora and floral habitat is considered to be of medium significance. Severity of Impact 2 Extent of Impact 2 Duration of Impact 2 Impact Significance = 8 i.e. Medium
Impact of Fauna & Faunal Habitat Majority of the wells are located on manmade ecological habitat, only one well (W-10) located in forest land. Out of 30 planned wells, 14 wells falls within 10km of both Dibru Saikhowa National Park as well as Bherjan Borjan Padumoni Wild life Sanctuary and 14 wells are located within 10km of only Dibru Saikhowa National Park and 1 well is situated within 10 km of only Bherjan Borjan Padumoni Wild Life Sanctuary. Ecological baseline study reveals that, Dibru-Saikhowa National Park and Padumoni Segment of Bherjan- Borajan-Padumoni WLS are habitats for elephant, hoolock gibbon, leopard, leopard cat, jungle cat, capped langur, slow loris hornbills, vulture etc. In addition Dibru-Saikhowa National Park has been reported as Important Bird Area. Considering the nature of project activity, it may be stated that the existing habitats, except for areas to be cleared (Well 10), will not undergo any further degradation during site preparation and operational stages of the project. However, noise generated from drilling activity, lighting at well site, traffic movement will cause of disturbance to wildlife. Taking presence of protected ecological habitats and few Schedule I species into account, in proximity to the proposed well sites, impact on fauna and faunal habitat is considered to be of high significance. Severity of Impact 3 Extent of Impact 2 Duration of Impact 2 Impact Significance = 12 i.e. High In view of proposed sensitivities and proximity to the National Park and Wildlife Sanctuary OIL will prepare site specific Wildlife Management Plan and get it approved from the National Board of Wildlife. OIL will also take specific measures for implementation of the Wildlife Management Plan.
Impact on Endangered/Threatened Flora and Fauna
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Dibru-Saikhowa National Park and Padumoni & Bherjan segments of Bherjan-Borajan- Padumoni Wildlife Sanctuary located in or at close proximity to Khagarijan Field are known habitats of the endangered hoolock gibbon, elephant, leopard, leopard cat, capped langur and few Schedule I birds and reptile species. Noise, vibration and light generated during drilling (operation of the rig) are expected to cause significant impact on protected animal species. Severity of Impact 3 Extent of Impact 2 Duration of Impact 2 Impact Significance = 12 i.e. High
Impact on Sensitive Ecological Habitat, Migratory Corridor & Route As discussed in the ecological environmental section of the report, Dibru-Saikhowa National Park and Padumoni & Bherjan segments of Bherjan-Borajan-Padumoni Wildlife Sanctuary. is located within or at close proximity to the Khagarijan Field. As discussed earlier, 14 wells falls within 10km of both Dibru Saikhowa National Park as well as Bherjan Borjan Padumoni Wild life Sanctuary and 14 wells are located within 10km of only Dibru Saikhoawa Nationaal Park and 1 well is situated within 10 km of only Bherjan Borjan Padumoni Wild Life Sanctuary. Also Dibru-Saikhowa National Park has been reported as Important Bird Area. The buffer along with the core of the National Park is also significant in the fact that it forms an overlap for two major avian migratory flyways- the East Asian and central Asian. Maguri- Motapung wetland complex near Guijan is considered as a haven for migratory birds..Taking into account the presence of sensitive ecological habitats and migratory routes within the Field the impact due to drilling activity within the Field is considered to be of high significance. Severity of Impact 3 Extent of Impact 2 Duration of Impact 2 Impact Significance = 12 i.e. High As discussed earlier, OIL will prepare site specific Wildlife Management Plan and get approved from the National Board of Wildlife besides taking specific measures for implementation of the Wildlife Management Plan.
Aquatic Habitat, Aquatic Flora & Fauna The major rivers viz. Brahmaputra, Dibru, Dinjan and Mai Jan , wetland complexes of Maguri-Motapung forms the aquatic ecosystem in the Khagarijan Field and its immediate proximity. It has been established in the baseline studies, that existing water quality of the surface water bodies is quite favorable to support diverse range of aquatic fauna and flora. The aquatic habitat within or at proximity to the Field is habitat for migratory birds. Brahmaputra River and its tributaries are also habitat for endangered Gangetic dolphin (Platanista gangetica). Few well sites (Wells, 1, 14, 15, 19, 20, 28 etc.) are located close to the Brahmaputra River or the wetland complex. Therefore, in case of any discharge of untreated waste water from drilling site may result in the possible contamination of receiving streams and their ecological habitat. Surface runoff during monsoon from the construction site of the wells has the potential to contaminate receiving surface water bodies thereby
SENES/K-20197/ November 2013 136 Oil India Ltd. Pre Drill EIA for Drilling of 30 wells at Khagarijan Field impacting their aquatic ecology. Again, all such process water to be discharged offsite will be undergoing adequate treatment to comply with discharge standards specified by regulatory authorities. Adequate treatment coupled with dilution factor of receiving water bodies will thus significantly contribute in preventing any deleterious effect on the aquatic ecological habitat.
Severity of Impact 2 Extent of Impact 2 Duration of Impact 2 Impact Significance = 8 i.e. Medium
4.2.11 Impact on Socioeconomic Environment Based on the nature and type of impacts, the assessment has been divided into broad categories namely (i) Adverse impacts and (ii) Positive impacts.
Adverse Impact Loss of Livelihood The proposed tentative well location map shows that, out of 30 wells, 29 wells are located in agricultural land, homestead tea gardens and plantation areas of tea estates. Approximately, 2.2 ha land per well will be required for proposed drilling activity. The agricultural lands are primarily mono-crop land. OIL will procure this land through private negotiation. In all cases, necessary payments will be made against purchase and crop compensation to concerned land owners. The proposed project would not require any displacement of villagers. The impact on livelihood is considered to be of medium significance. Severity of Impact 2 Extent of Impact 2 Duration of Impact 3 Impact Significance = 8 i.e. Medium
Conflicts on Job Opportunity Primary survey and discussion with villagers showed that the local people desired to work in OIL. Involvement of outside workers in proposed activity may possibly create conflict with the local people, as most of the villagers are small scale cultivators, tea garden workers, daily labours or small businessmen. Severity of Impact 2 Extent of Impact 2 Duration of Impact 2 Impact Significance = 8 i.e. Medium
Disruption on Infrastructure Road network in Khagarijan Field are observed to be primarily of weathered black top roads and internal village roads and tea garden roads are Kutcha road. Number of access roads to the well sites passes through villages and tea gardens’ internal road. Transportation of drilling rig and associated facilities to drill site and decommissioning of rig and associated structure
SENES/K-20197/ November 2013 137 Oil India Ltd. Pre Drill EIA for Drilling of 30 wells at Khagarijan Field will increase traffic movement. An abrupt increase in vehicular fleet may damage road infrastructure if not properly maintained. Severity of Impact 2 Extent of Impact 2 Duration of Impact 2 Impact Significance = 8 i.e. Medium
Dust and Noise Discomfort Majority of wells are located in close proximity to settlement. Inhabitants residing close to access roads will get affected due to noise and dust generated from vehicular movement during site preparation, setting up of rig and associated facilities , decommissioning of rig and associated facilities. Again, during drilling operation, inhabitants residing close to drill sites (within 250 m) will get affected due to noise and emissions from DG sets and occasional flaring activity. Considering proximity of human settlement and short term activity with proper mitigation measures, impact will be of Medium significance. Severity of Impact 2 Extent of Impact 2 Duration of Impact 2 Impact Significance = 8 i.e. Medium
Ecological Productivity of Agricultural Fields Ecological productivity of the agricultural land taken up for drilling activity stands temporarily affected during the entire lifecycle of the project. Reinstatement of ecological productivity will be dependent on successful restoration of soils, their structure, chemistry drainage characteristics and possibly other physical factors, such as micro-topography. These will provide a basis for successful recovery of ecological populations, whether allowed to occur naturally or aided by seeding and cultivation. However, considering necessary mitigation measures like top soil preservation, process water treatment, etc will be implemented by the proponent. During various project phases any impact in this regard is considered to be of low significance. Severity of Impact 2 Extent of Impact 2 Duration of Impact 1 Impact Significance = 4 i.e. Low
Influx of Population Influx of population is anticipated in all stages of the project cycle particularly during the drilling activities. The drill site will involve the operation of about 50 onsite workers. Hence there might be an impact on the local communities due to the sharing of common resources like space, drinking water, roads etc. Interaction between workers with villagers of nearby areas might give rise to various issues like conflict of workers with the local population, nuisance caused by workers due to improper sanitation facilities etc. However, taking into account that workforce is likely to be sourced from nearby villages and adequate sanitation facilities will be provided chances of such conflicts are medium.
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Severity of Impact 2 Extent of Impact 2 Duration of Impact 2 Impact Significance = 8 i.e. Medium
Community Health & Safety Community health and safety of inhabitants residing close to the drilling site stands to get affected from frequent heavy vehicular movement along village access roads and due to noise from drilling rig operations. Health and safety impact arising from technological emergencies viz. well blow outs, explosions will be dealt separately in the QRA section. Although the aforesaid activities are temporary in nature it may not adversely affect community health and safety and hence is considered to be of medium significance. Severity of Impact 2 Extent of Impact 2 Duration of Impact 2 Impact Significance = 8 i.e. Medium
Cultural & Heritage Site Impact on cultural environment may occur due to site preparation, operation of drilling rig and also during vehicular movement with respect to the proposed drilling activities. There are no designated historical or cultural spots within Khagarijan Field. The project will however be adopting following mitigation measures to prevent any adverse impact to properties/remains of cultural and historical significance of any such remains accidentally encountered during aforesaid activities. Prior to commencement of site construction activities, location of cultural important properties will be communicated to the contractor; and reporting of chance find of any properties/remains of archeological significance by the contractor to the proponent. Thus any significant impact due to project activities on cultural environment of the block is unlikely. Severity of Impact 1 Extent of Impact 2 Duration of Impact 1 Impact Significance = 2 i.e. Low
Positive Impacts
Employment opportunities
Project will benefit people living in the neighboring villages by giving preference to them in relation to direct & indirect employment associated with the various project activities. Site preparation phase will involve certain number of laborers and there is a possibility that local people can be engaged for this purpose. Drilling process will involve a number of skilled and unskilled workers. There is a possibility that local people will be engaged for this purpose to the extent possible and hence improve existing employment scenario of the region. However, most jobs will comprise technical involvement. Hence villagers can possibly be employed only in certain non-technical or casual labor jobs and that too for a limited
SENES/K-20197/ November 2013 139 Oil India Ltd. Pre Drill EIA for Drilling of 30 wells at Khagarijan Field duration. It is proposed that first preference be given to people whose land is acquired and to their relations. Next preference will be given to the poorer people and subsequently the other villagers.
Impact Significance = ++ i.e. POSITIVE
4.2.12 Impact on Occupational Health and Safety Occupational injuries and ill-health have huge socio-economic implications on individuals, their families and communities. They also have economic impacts in form of direct and indirect costs for society as a whole. Major occupational health risks encountered in proposed drilling activity include noise from drilling activity, operation of heavy vehicles and machinery, handing of chemicals. However, the proponent will adopt necessary control measures through implementation of mitigation measures and provision of proper PPEs to workers operating in aforesaid area, to prevent and/or mitigate adverse health related impacts. The workers will also be made aware about the potential risks and preventive measure through regular training programs. Hence any possible occupational health impact from exposure to such fugitive dust is not likely to be of major significance. Severity of Impact 2 Extent of Impact 2 Duration of Impact 2 Impact Significance = 8 i.e. Medium
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TABLE 4-8: IMPACT SIGNIFICANCE MATRIX (WITH MITIGATION)
Environment Physical Environment Biological Environment Socio-economic Environment
bitat
Activity
Aesthetics &Visuals Aesthetics AirQuality NoiseQuality & Traffic Transport Use Land SoilQuality Habitat & Flora Floral Ha Wildlife Fauna &Endangered Threatened species &route corridor Migratory Habitat Aquatic &Fauna Flora Aquatic Livelihood of Loss opportunity Job on Conflict Infrastructure of Disruption Resources Property Common Discomfort &Noise Dust Agricultural of Loss Productivity Population of Influx Site & Heritage Cultural Opportunity Economic & Job &Safety Health Occupational Safety & Health Community Local Local Physiography Drainage & Resources Water Surface quality water Surface Ground Resources Water Groundquality water A. Pre-Drilling Activities Site selection and land acquisition M M L Site clearance and top soil removal L L L M M M M L L + L Well site& access road construction L L L M M L + L L Sourcing & transportation of borrow material etc L L L M L L M M M M L + L L Storage and handling of construction debris L L L Transportation of drilling rig and ancillaries L L M L M L L L
Operation DG set L L M M M Workforce engagement & accommodation at construction site M L M + L Consumption of water for construction & domestic use for labourer L L Generation of domestic solid waste & disposal L L L L M M L Generation of waste water & discharge from construction activity & labour camp L L L Surface run-off from construction site L M L L L L B. Drilling & Testing Physical Presence at drill site L M M M Operation of DG sets and machinery L M H H H H M M
Operation of drilling rig M H H H H M M Storage and disposal of drill cuttings and mud L L L L Generation of process waste water & discharge M L M M Surface run-off from drill site L L M M Generation of domestic waste water & discharge L L L M M Generation of Municipal waste & disposal L L L L Workforce engagement & accommodation at drill site M L M + M Flaring during production testing and process upset L M M H H H H M M Accidental events - blow out L M M M M H H H H L L M M Accidental events-spillage of chemical & oil M M M M M C. Decommissioning and Reinstatement Dismantling of rig and associated facilities L L M M Transportation of drilling rig and ancillaries L L M M Removal of well site construction materials & disposal L L M Site Restoration + + +
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5 Quantitative Risk Assessment
This section on Quantitative Risk Assessment (QRA) aims to provide a systematic analysis of the major risks that may arise as a result of drilling and testing activities by OIL in the Khagarijan Field. The QRA process outlines rational evaluations of the identified risks based on their significance and provides the outline for appropriate preventive and risk mitigation measures. Results of the QRA provides valuable inputs into the overall project planning and the decision making process for effectively addressing the identified risks. This will ensure that the project risks stay below As Low as Reasonably Practicable (ALARP) levels at all times during project implementation. In addition, the QRA will also help in assessing risks arising from potential emergency situations like a blow out and develop a structured Emergency Response Plan (ERP) to restrict damage to personnel, infrastructure and the environment.
BOX 5.1: QRA – INTEGRATED RISK MANAGEMENT PROCESS
QRA as a part of integrated risk management process for the proposed project consists of the following iterative steps:
Identification of hazards Setting Acceptance Standards for the defined risks Evaluation of likelihood and consequences and risks of possible events. Confirmation of arrangements to mitigate the events and respond to the same on occurrence. Establishment of performance standards Establishment of continuous monitoring, review and auditing of arrangements
The risk study for the drilling and testing activities has considered all aspects of operation of the drilling rig and other associated activities during the drilling phase. Oil spills, loss of well control / blow-out and process leaks constitute the major potential hazards that may be associated with the proposed drilling for oil and gas in the Khagarijan Field. The study however does not examine the risks or hazards associated with development and production program of the wells. The following section describes objectives, methodology of the risk assessment study and then presents the assessment for each of the potential risk separately. This includes identification of major hazards, hazard screening and ranking, frequency and consequence analysis for major hazards. The hazards have subsequently been quantitatively evaluated through a criteria based risk evaluation matrix. Risk mitigation measures to reduce significant risks to acceptable levels have also been recommended as a part of the risk assessment study.
5.1 OBJECTIVE OF THE QRA STUDY
The overall objective of this QRA with respect to the proposed project involves identification and evaluation of major risks, prioritizing risks identified based on their hazard consequences and formulating suitable risk reduction/mitigation measures in line with the ALARP
SENES/K-20197/ November 2013 142 Oil India Ltd. Pre Drill EIA for Drilling of 30 wells at Khagarijan Field principle. Hence in order to ensure effective management of any emergency situations (with potential individual and societal risks) that may arise during the drilling activities, following specific objectives need to be achieved. Identify potential risk scenarios that may arise out of proposed drilling activities like operation of ancillary facilities and equipments, mud chemicals storage and handling etc. Analyze the possible likelihood and frequency of such risk scenarios by reviewing historical accident related data for oil and gas industries. Predict the consequences of such potential risk scenarios and if consequences are high, establish the same by through application of quantitative simulations. Recommend feasible preventive and risk mitigation measures as well as provide inputs for drawing up of Emergency Management Plan (EMP) for the project.
5.2 RISK ASSESSMENT METHODOLOGY The risk assessment process is primarily based on likelihood of occurrence of the risks identified and their possible hazard consequences particularly being evaluated through hypothetical accident scenarios. With respect to the proposed project, major risks viz. blow outs, process leaks and fires, non-process fires etc. have been assessed and evaluated through a risk matrix generated to combine the risk severity and likelihood factor. Risk associated with the drilling activities have been determined semi- quantitatively as the product of likelihood/probability and severity/consequence by using order of magnitude data (risk ranking = severity/consequence factor X likelihood/probability factor). Significance of such project related risks was then established through their classification as high, medium, low, very low depending upon risk ranking. The risk matrix is a widely accepted as standardized method of quantitative risk assessment and is preferred over purely quantitative methods, given that its inherent limitations to define a risk event is certain. Application of this tool has resulted in the prioritization of the potential risks events for the drilling thus providing the basis for drawing up risk mitigation measures and leading to formulation of plans for risk and emergency management. The overall approach is summarized in the Figure 5.1
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FIGURE 5-1: RISK ASSESSMENT METHODOLOGY
5.2.1 Hazard Identification Hazard identification for the purposes of this QRA comprised of a review of the project and associated activity related information provided by OIL as part of its Emergency Response Plan. In addition, guidance provided by knowledge platforms/portals of the upstream oil & gas industry including OGP, ITOPF and DNV, Norwegian Petroleum Directorate etc. are used to identify potential hazards that can arise out of proposed project activities. Taking into account the applicability of different risk aspects in context of the drilling operations to be undertaken in the Khagarijan Field, there are three major categories of hazards that can be associated with proposed project which has been dealt with in detail. This includes: Blowouts leading to pool fires/jet fires and oil spills Process leaks and fires Non-process fires / explosions
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Well control incident covers a range of events which have the potential of leading to blow- outs but are generally controlled by necessary technological interventions. Hence, such incidents are considered of minor consequences and as a result not well documented. Other possible hazard scenarios like mud chemical spills, falls etc. has also not been considered for detailed assessment as preliminary evaluation has indicated that the overall risk that may arise out of them would be low. In addition, it is understood that, causative factors and mitigation measures for such events can be adequately taken care of through exiting safety management procedures and practices of OIL. Further, taking into account vulnerability of the project region to floods as discussed in section 3.1.12 due consideration has been given in identifying hazards and risks arising out of such natural calamities/hazards in the risk assessment study undertaken for the drilling activities. It must also be noted here that many hazards identified are sometimes interrelated with one hazard often having the ability to trigger off another hazard through a domino effect. For example, a large oil spill in most instances is caused by another hazardous incident like a blowout or process leak. This aspect has been considered while drawing up hazard mitigation measures and such linkages (between hazards) has also been given due importance for managing hazards and associated risks in a composite manner through OIL’s Health, Safety & Environmental Management System (HSEMS) and through the Emergency Management Plan, if a contingency situation so arises.
5.2.2 Frequency Analysis Frequency analysis involves estimating the likelihood of each of the failure cases identified during the hazard identification stage. The analysis of frequencies of occurrences for the key hazards that has been listed out is important to assess the likelihood of such hazards to actually unfold during the lifecycle of the project. The frequency analysis approach for the proposed project is based primarily on historical accident frequency data, event tree analysis and judgmental evaluation. Major oil and gas industry information sources viz. statistical data, historical records and global industry experience were considered during the frequency analysis of the major identified risks16. For QRA for the proposed project, various accident statistics and published oil industry databases have been consulted for arriving at probable frequencies of identified hazards. However, taking into account the absence of representative historical data/statistics with respect to onshore operations17, relevant offshore accident databases have been considered in
16 It is to be noted that the frequency of occurrences are usually obtained by a combination of component probabilities derived on basis of reliability data and /or statistical analysis of historical data.
17 Although Alberta Energy & Utilities Board (EUB) maintains a database for onshore incidents for the period 1975-1990 the same has not been considered in the context of the present study as the Alberta wells are believed to be sour with precaution being taken accordingly to minimize the likelihood of release.
SENES/K-20197/ November 2013 145 Oil India Ltd. Pre Drill EIA for Drilling of 30 wells at Khagarijan Field the frequency analysis of identified hazards. The same has been recommended in the “Risk Assessment Data Directory” published by the International Association of Oil & Gas Producers (OGP). Key databases/reports referred as part of the QRA study includes Worldwide Offshore Accident Databank (WOAD), Outer Continental Shelf (OCS) Reports, Norwegian Petroleum Directorate Directives, Offshore Reliability Data (OREDA) Handbook, HSE Offshore Incident Database, SINTEF Offshore Blowout Database etc. Based on the range of probabilities arrived at for different potential hazards that may be encountered during the proposed drilling activities, following criteria for likelihood rankings have been drawn up as presented in the Table 5.1. Table 5-1: Frequency Categories and Criteria Criteria Ranking Likelihood Ranking Frequency Class (cases/year)
5 >1.0 Frequent 4 >10-1 to <1.0 Probable 3 >10-3 to <10-1 Occasional/Rare 2 >10-5 to <10-3 Not Likely 1 >10-6 to <10-5 Improbable
5.2.3 Consequence Analysis In parallel to frequency analysis, hazard prediction / consequence analysis exercise assesses resulting effects in instances when accidents occur and their likely impact on project personnel, infrastructure and environment. In relation to the proposed project, estimation of consequences for each possible event has been based either on accident experience, consequence modeling or professional judgment, as appropriate. Given the high risk perception associated with blow outs in context of onshore drilling operation, a detailed analysis of consequences has been undertaken for blow outs taking into account physical factors and technological interventions. Consequences of such accidental events on the physical, biological and socio-economic environment have been studied to evaluate the potential of the identified risks/hazards. In all, the consequence analysis takes into account the following aspects: Nature of impact on environment and community; Occupational health and safety; Asset and property damage; Corporate image Timeline for restoration of environmental and property damage Restoration cost for environmental and property damage
The following criterion for consequence rankings (Table 5.2) is drawn up in context of the possible consequences of risk events that may occur during proposed drilling activities:
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Table 5-2: Severity Categories and Criteria
Consequence Ranking Criteria Definition
Catastrophic 5 Multiple fatalities/Permanent total disability to more than 50 persons Severe violations of national limits for environmental emission More than 5 years for natural recovery Net negative financial impact of >10 crores Long term impact on ecologically sensitive areas International media coverage National stakeholder concern and media coverage Major 4 Single fatality/permanent total disability to one or more persons Major violations of national limits for environmental emissions 2-5 years for natural recovery Net negative financial impact of 5 -10 crores Significant impact on endangered and threatened floral and faunal species Loss of corporate image and reputation Moderate 3 Short term hospitalization & rehabilitation leading to recovery Short term violations of national limits for environmental emissions 1-2 years for natural recovery Net negative financial impact of 1-5 crores Short term impact on protected natural habitats State wide media coverage Minor 2 Medical treatment injuries 1 year for natural recovery Net negative financial impact of 0.5 – 1 crore Temporary environmental impacts which can be mitigated Local stakeholder concern and public attention Insignificant 1 First Aid treatment with no Lost Time Incidents (LTIs) Natural recovery < 1year Net negative financial impact of <0.5 crores. No significant impact on environmental components No media coverage
5.2.4 Risk Evaluation Based on ranking of likelihood and frequencies, each identified hazard has been evaluated based on the likelihood of occurrence and the magnitude of consequences. Significance of
SENES/K-20197/ November 2013 147 Oil India Ltd. Pre Drill EIA for Drilling of 30 wells at Khagarijan Field risks is expressed as the product of likelihood and consequence of the risk event, expressed as follows: Significance = Likelihood X Consequence The Table 5.3 below illustrates all possible product results for five likelihood and consequence categories while the Table 5.4 assigns risk significance criteria in four regions that identify the limit of risk acceptability as per the HSE management system of OIL Depending on the position of intersection of a column with a row in the risk matrix, hazard prone activities have been classified as low, medium and high thereby qualifying a set of risk reduction / mitigation strategies. Table 5-3: Risk Matrix
Likelihood → Frequent Probable Remote Not Likely Improbable
5 4 3 2 1
→
Catastrophic 5 25 20 15 10 5
ence ence Major 4 20 16 12 8 4
Moderate 3 15 12 9 6 3 Consequ Minor 2 10 8 6 4 2
Insignificant 1 5 4 3 2 1
TABLE 5-4: RISK CRITERIA AND ACTION REQUIREMENTS
Risk Significance Criteria Definition & Action Requirements
“Risk requires attention” – Project HSE Management need to ensure High (16 - 25) that necessary mitigation are adopted to ensure that possible risk remains within acceptable limits
“Risk is tolerable” – Project HSE Management needs to adopt necessary Medium (10 – 15) measures to prevent any change/modification of existing risk controls and ensure implementation of all practicable controls.
“Risk is acceptable” – Project related risks are managed by well- Low (5 – 9) established controls and routine processes/procedures. Implementation of additional controls can be considered.
“Risk is acceptable” – All risks are managed by well-established Very Low (1 – 4) controls and routine processes/procedures. Additional risk controls need not to be considered
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5.3 RISK ASSESSMENT OF IDENTIFIED PROJECT HAZARDS
As already discussed in the previous section, three major categories risk have identified in relation to proposed drilling activities. A comprehensive risk assessment study has been undertaken to assess and evaluate significance of identified risks in terms of severity of consequences and likelihood of occurrence. Risk assessment study details have been summarized in the subsequent sections below:
5.3.1 Blow Outs/Loss of Well Control Blow out is an uncontrolled release of well fluid (primarily hydrocarbons viz. oil and/or gas and may also include drilling mud, completion fluid, water etc) from well bore. Blow outs are the result of failure to control a kick and regain pressure control and are typically caused by equipment failure or human error. The possible blow out cause events occurring in isolation or in combination have been listed below: Formation fluid entry into well bore Loss of containment due to malfunction (viz. wire lining) Well head damage (e.g. by fires, storms, dropped object etc) Rig forced off station (e.g. by anchor failure) damaging Blow Out Preventor (BOP) or wellhead
The most common cause of blow out can be associated with the sudden/unexpected entry/release of formation fluid into well bore that may arise as a result of the following events as discussed in the Box 5.2 below.
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BOX 5.2: PRIMARY CAUSES OF BLOW OUTS
Shallow gas In shallow formations there may be pockets of shallow gas. In these instances there is often insufficient mud density in the well and no BOP is in place. If the hole strikes shallow gas the gas may be released on the drilling rig very rapidly. Typical geological features which suggest the presence of shallow gas can then be detected. Historically, striking of shallow gas has been one of the most frequent causes of blowouts in drilling.
Swabbing As the drill pipe is pulled upwards during trips out of the hole or upward movement of the drill string, the pressure in the hole beneath the drill bit is reduced, creating a suction effect. Sufficient drilling mud must be pumped down-hole to compensate for this effect or well fluids may enter the bore. Swabbing is also a frequent cause of drilling blowouts.
High formation pressure Drilling into an unexpected zone of high pressure may allow formation fluids to enter the well before mud weight can be increased to prevent it.
Insufficient mud weight The primary method of well control is the use of drilling mud; in correct operation, the hydrostatic pressure exerted by the mud prevents well fluids from entering the well bore. A high mud weight provides safety against well fluids in-flows. However, a high mud weight reduces drilling speed, therefore, mud weight is calculated to establish weight most suitable to safely control anticipated formation pressures and allows optimum rates of penetration. If the required mud weight is incorrectly calculated then well fluid may be able to enter the bore.
Lost Circulation Drilling mud circulation can be lost if mud enters a permeable formation instead of returning to the rig. This reduces the hydrostatic pressures exerted by the mud throughout the well bore, and may allow well fluids from another formation to enter the bore.
Gas cut mud Drilling fluids are denser than well fluids; this density is required to provide the hydrostatic pressure which prevents well fluids from entering the bore. If well fluids mix with the mud then its density will be reduced. As mud is circulated back to surface, hydrostatic pressure exerted by the mud column is reduced. Once gas reaches surface it is released into the atmosphere.
Source: A Guide to Quantitative Risk Assessment for Offshore Installations; John Spouge – DNV Technica Publication 99/100a For better understanding, causes of blow outs have been systematically defined in terms of loss of pressure control (failure of primary barrier), uncontrolled flow of fluid or failure of secondary barrier (BOP). The blow out incidents resulting from primary and secondary failures for proposed operations as obtained through comprehensive root cause analysis of the
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Gulf Coast (Texas, OCS and US Gulf of Mexico) Blow Outs18 during 1960-1996 have been presented in the Table 5.5 below. Table 5-5: Blow Out Cause Distribution for Failures during Drilling Operations
Sl. No Causal Factors Blow Out Incidents (nos.)
A Primary Barrier 1 Swabbing 77 2 Drilling Break 52 3 Formation breakdown 38 4 Trapped/expanding gas 09 5 Gas cut mud 26 6 Low mud weight 17 7 Wellhead failure 05 8 Cement setting 05 B Secondary Barrier 1 Failure to close BOP 07 2 Failure of BOP after closure 13 3 BOP not in place 10 4 Fracture at casing shoe 03 5 Failure to stab string valve 09 6 Casing leakage 06
Thus, underlying blowout causes as discussed in the above table can be primarily attributed to swabbing as the primary barrier failure which is indicative of insufficient attention given to trip margin and controlling pipe movement speed. Also, it is evident from the above table that lack of proper maintenance, operational failures and absence of BOPs as secondary barrier contributed to majority of blowout incidents (approx 30 nos.) is recorded.
Blowout Frequency Analysis Blow out frequency estimates is obtained from a combination of incident experience and associated exposure in a given area over a given period. For the purpose of calculation of blow out frequency analysis in context of the present study involving drilling operations, blow out frequencies per well drilled have been considered. However due to the lack of availability of representative data on onshore blow out incidents relevant offshore accident database viz. SINTEF Offshore Blowout Database, OGP Risk Assessment Data Directory (RADD) and Scandpower which have been referred. The blow out frequency per operation as calculated is based on the SINTEF Offshore Blowout Database for oil and gas extraction industry has been presented in the Figure 5.2 below.
18 “Trends extracted from 1200 Gulf Coast blowouts during 1960-1996” – Pal Skalle and A.L.Podio
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FIGURE 5-2: BLOW OUT FREQUENCIES IN OIL & GAS INDUSTRY
With respect to the proposed project, the blow out occurrence frequency as based on analysis of historical data19 has been considered to be 7.5 X 10-3 per well drilled. Based on the given frequency and information provided by OIL on the proposed project drilling program the blow out frequency is calculated as follows:
No of wells to be drilled = 30 (A) Blow out frequency for drilling = 7.5 X 10-3 per well drilled (B) Frequency of blow out occurrence for the proposed project = (A X B) = 30 X 7.5 X 10-3 = 2.25 X 10-1 per well drilled
Thus, the blow out frequency for the proposed project is calculated at 2.25 X 10-1 per well drilled i.e. the likelihood of its occurrence is “Probable”
Blowout Consequence Analysis Blow out from a hydrocarbon well may lead to the following possible risk consequences: Pool fires and smoke plumes resulting from ignited oil blow outs
19 Analysis of the SINTEF database for the US GoM OCS/North Sea for the period 1980-92 by Scandpower (1995)
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Jet fires resulting from ignited gas blow outs Oil slicks resulting from un-ignited oil pools.
Pool fire
A pool fire is a turbulent diffusion fire burning above a pool of vaporizing hydrocarbon fuel where the fuel vapor has negligible initial momentum. The probability of occurrence of pool fires for oil and gas exploration is high due to continuous handling of heavy hydrocarbons. The evaporation of hydrocarbons from a pool forms a cloud of vapor above the pool surface which, on ignition, leads to generation of pool fire. For the purpose of consequence modeling for pool fires resulting from blow outs, following hypothetical scenarios in terms of hydrocarbon (particularly crude oil) release rates (Table 5.6) have been considered based on DNV Technica’s FLARE program.
TABLE 5-6: POOL FIRE MODELING SCENARIOS
Scenario Release Rate (kg/s) Release Type Scenario - I 1 Small Scenario - II 10 Medium Scenario – III (Worst Case) 50 Large
The release rates as specified for the aforesaid scenarios have been utilized in the computing the pool fire diameter utilizing the following equation and input parameters: D = √4Q/πb Where D = pool diameter (m) Q = release rate (kg/s) b = burning rate (kg/m2s) The mass burning rate for crude oil has been considered to be 0.05 kg/m2s Based on above equation, the pool fire diameter and the steady study burning areas computed for various release types have been presented in the Table 5.7 below.
TABLE 5-7: POOL FIRE DIAMETER & STEADY STATE BURNING AREA
Release Release Pool fire Steady State Scenario Rate (kg/s) Type diameter (m) Burning Area (m2) Scenario - I 1 Small 5.05 6.37 Scenario - II 10 Medium 15.96 63.69 Scenario - III 50 Large 35.69 318.47
The impact zone for long duration fires is conveniently described by thermal radiation contours and its effects on the people who are exposed to such radiation levels for one minute
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(60sec). The thermal radiation threshold values (measured in kilowatts per square meter) defined for crude oil pool fire consequence modeling is provided in Table 5.8 below:
TABLE 5-8: THERMAL RADIATION INTENSITY THRESHOLD VALUES IMPACT CRITERION Threshold Radiation Threat Impact Criterion Intensity Zone Escape actions within one minute. 5.0 kW/m2 Green Cause second degree burns within 60 sec.
2 Escape actions lasting for few seconds. 12.5 kW/m Blue Cause second degree burns within 40 sec. Results in immediate fatality. 2 37.5 kW/m Red Pain threshold is instantaneous leading to second degree burns within 8 sec.
For estimating the distance to a pool fire heat radiation level that could cause second degree burns and fatality for a maximum exposure of 60 sec the following EPA equation and input parameters are utilized.
0.0001 A X Hc 5000 (Hv Cp (TB - TA ))
Where: X = distance to the heat radiation level (m) HC = heat of combustion of the flammable liquid (joules/kg) HV = heat of vaporization of the flammable liquid (joules/kg) A = pool area (m2) CP = liquid heat capacity (joules/kg-ºK) TB = boiling temperature of the liquid (ºK) TA = ambient temperature (ºK) For crude oil HC = 42600000 joules/kg; HV = 957144 joules/kg; CP = 1892 joules/kg-ºK; TB = 633 ºK and TA = 300 ºK. The following input parameter along with pool area (m2) computed for blow out risk scenarios provided the distance to the threshold heat radiation levels for the threat zones and have been presented in Table 5.9 below
TABLE 5-9: DISTANCE TO THERMAL RADIATION THRESHOLD LEVELS
Distance to Distance to Distance to Release Pool fire Pool fire 5.0 kW/m2 12.5 kW/m2 37.5 kW/m2 Type diameter (m) area (m2) (m) (m) (m) Small 5.05 6.37 6.81 4.31 2.49 Medium 15.96 63.69 21.54 13.62 7.86 Large 35.69 318.47 48.16 30.46 17.59
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The worst hazard for release and ignition of crude oil at a rate of 50kg/s for a thermal radiation intensity of 37.5 kW/m2 is likely to be experienced to a maximum distance of 17.59m from the source with potential lethal effects experienced within 8 sec. Risk Ranking – Blowout Pool Fire (Worst Case Scenario)
Likelihood ranking 3 Consequence ranking 4
Risk Ranking & Significance = 12 i.e. “Medium”
Jet fire
Jet fires are burning jet of gas or sprays of atomized liquids resulting from gas and condensate release from high pressure equipment and blow outs. Jet fires may also result in the release of high pressure liquid containing dissolved gas due to gas flashing off and turning the liquid into a spray of small droplets. In context of the present study, formation of jet fires can be attributed by the high pressure release and ignition of natural gas if encountered during exploration of block hydrocarbon reserves.
Natural gas as recovered from underground deposits primarily contains methane (CH4) as a flammable component, but it also contains heavier gaseous hydrocarbons such as ethane
(C2H6), propane (C3H8) and butane (C4H10). Other gases such as CO2, nitrogen and hydrogen sulfide (H2S) are also often present. Methane is typically 70-90 percent, ethane 5-15 percent, propane and butane, up to 5 percent. Thus, considering higher percentage of methane in natural gas, the thermo-chemical properties of the same has been utilized in the jet fire blow out consequence modeling. The following risk scenarios (Table 5.10) have been considered for jet fire consequence modeling:
TABLE 5-10: JET FIRE MODELING SCENARIOS
Scenario Release Rate (kg/s) Release Type Scenario - I 1 Small Scenario - II 5 Medium Scenario – III (Worst Case) 10 Large Gas release rates for each scenario have been utilized in the calculating jet fire flame length. Flame length calculation is done using API RP521 (API 1982) model and is based on the fuel type 0.41 Lf = 0.00326 (Q Hc) Where
Lf = flame length (m) Q = release rate (kg/s)
7 Hc = heat of combustion (J/kg) i.e. (5.0 X 10 J/kg for methane)
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The flame length calculated based on the above equation for jet fire is presented in the Table 5.11 below.
TABLE 5-11: JET FIRE FLAME LENGTH FOR RISK SCENARIOS CONSIDERED
Scenario Release Rate (kg/s) Release Type Flame Length (m)
Scenario - I 1 Small 4.68 Scenario - II 5 Medium 9.04 Scenario – III (Worst Case) 10 Large 12.02
The thermal radiation intensity threshold values and its possible impacts for jet fire is similar to that considered for pool fire (Refer Table 5.8) The distance to the radiation intensity levels for risk scenarios have been predicted based on the Chamberlain model calculation. The following relationships for distance along the flame axis to various thermal radiation levels have been calculated:
2 0.447 For 5.0 kW/m ; Lf = 19.50 (Q) 2 0.447 For 12.5 kW/m ; Lf = 16.15 (Q) 2 0.447 For 37.5 kW/m ; Lf = 13.37 (Q)
Where Lf = flame length (m) Q = release rate (kg/s) Based on equation specified for thermal radiation intensities the distance of flame calculated for various gas release rates under risk scenarios discussed have been presented in the Table 5.12 below.
TABLE 5-12: JET FIRE HAZARD RANGES
Release Rate Distance to 5.0 Distance to 12.5 Distance to 37.5 Release Type (kg/s) kW/m2 (m) kW/m2 (m) kW/m2 (m) Small 1 19.5 16.2 13.4 Medium 5 40.0 33.2 27.5 Large 10 54.6 45.2 37.4
As provided in the above table the flame length for the jet fire risk scenarios considered at respective threshold radiation intensity values is likely to vary from 19.5 – 54.6m for 5.0 kW/m2 thermal radiation 16.2 – 45.2m for 12.5 kW/m2 thermal radiation 13.4 – 37.4m for 37.5 kW/m2 thermal radiation
The worst hazard for release and ignition of natural at a rate of 10kg/s for a thermal radiation intensity of 37.5 kW/m2 is likely to be experienced to a maximum distance of 37.4m from the source with potential lethal effects likely to be experienced within 8 sec.
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Risk Ranking – Blowout Jet Fire (Worst Case Scenario)
Likelihood ranking 3 Consequence ranking 4
Risk Ranking & Significance = 12 i.e. “Medium”
Oil Spill
Crude oil spills resulting from blow out may result in the formation of un-ignited pools of liquid the spreading of which is governed by physical factors viz. wind speed, sea currents (for offshore spills), release rates and spilled chemical characteristics viz. density. Near to the source of a continuous release, the spreading is dominated by gravity and limited by internal forces with thickness generally varying within 10-20 mm. The spill movement is then resisted by the viscous shear forces which then continue until the spill thickness is about 1.0 mm. Subsequently, surface tension takes over as the dominant spreading mechanism and it continues until the thickness has reduced to 0.01 – 0.1 mm which may take about 7-10 days for a large spill depending on various factors as discussed earlier. With respect to the QRA study hypothetical release rates of 1.0kg/s, 5.0 kg/s and 10.0 kg/s for 1 day, 4days and 7days respectively have been considered as the possible risk scenarios for modeling the spread of oil spill following a blow-out incident. The diameter of the pool in the first phase of an unignited continuous release is obtained by the following equation: 3/4 D = 2 [g X Q/ρL 2π] t Where D = pool diameter (m) g = acceleration due to gravity (m/s2) Q = release rate (kg/s)
3 3 ρL = liquid density (kg/m ) (crude oil density is 790 kg/ m ) t = time since start of release (s) The pool fire diameter so calculated for the aforesaid risk scenarios have been presented in the Table 5.13 below.
TABLE 5-13: POOL DIAMETER FOR OIL SPILL RISK SCENARIOS
Release Type Release Rate (kg/s) Release Time (s) Oil Spill Pool Diameter (m)
Small 1 86400 19.9 Medium 5 259200 226.9 Large 10 432000 665.7
Hence, for a worst case spill scenario involving a crude oil release rate of 10kg/s for a period of 7 days the pool diameter for an un-ignited continuous release is predicted to be about
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665.7 m. The ignition of the oil pool may lead to the formation of pool fires - consequences of which have been discussed earlier under the risk related to pool fires. Although the un- ignited pool is not considered to be of major significance, it may gain significance based on the environmental impacts that may result from it depending on sensitive receptors identified abutting the proposed project well sites. Risk Ranking – Blowout Oil Spills (Worst Case Scenario)
Likelihood ranking 3 Consequence ranking 4
Risk Ranking & Significance = 12 i.e. “Medium”
Preventive and Mitigation Measures Blowouts being events which may be catastrophic to any well operation, it is essential to take up as much a preventive measures as feasible. This includes: Necessary active barriers (eg. Well-designed Blowout Preventor) be installed to control or contain a potential blowout. Weekly blow out drills be carried out to test reliability of BOP and preparedness of drilling team. Close monitoring of drilling activity be done to check for signs of increasing pressure, like from shallow gas formations. Installation of hydrocarbon detectors. Periodic monitoring and preventive maintenance be undertaken for primary and secondary barriers installed for blow out prevention, including third party inspection & testing An appropriate Emergency Response Plan be finalized and implemented by OIL. Marking of hazardous zone (500 meters) around the well site and monitoring of human movements in the zone. Training and capacity building exercises/programs be carried out for onsite drilling crew on potential risks associated with exploratory and development drilling and their possible mitigation measures. Installation of mass communication and public address equipment. Good layout of well site and escape routes.
Additionally, OIL will be adopting and implementing the following Safe Operating Procedures (SOPs) developed as part of its Onsite Emergency Response Plan (currently in draft stage) to prevent and address any blow out risks that may result during drilling activities:
Blow Out Control Equipment Choke lines and Choke Manifold Installation with Surface BOP Kill Lines and Kill Manifold Installation with Surface BOP
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Control System for Surface BOP stacks Testing of Blow Out Prevention Equipment BOP Drills
5.3.2 Process Leaks/Fires Process leaks are can be defined as hydrocarbon releases from process equipments excluding blowouts and are relatively frequent events. In most cases they are small in nature and can be effectively controlled. However, if this is not possible, they can trigger events like fire or explosions which may potentially have higher consequences.
Process Leaks – Frequency Analysis The frequency of process leaks can be estimated directly from analysis of historical data obtained from E & P Forum hydrocarbon leak database (E&P forum 1992), World Offshore Accident Database (WOAD) and OREDA. Although onshore data is available for process leaks, the information is not considered representative of the actual scenario. Under such circumstances historical data available on hydrocarbon leaks in the OGP authenticated offshore accident databases have been considered for purpose of process leak frequency analysis. Review of HSE hydrocarbon release database indicates that majority of the leaks (approx 45%) occurred during production with drilling/well operation contributing is only 10%. Range of frequencies for various possible events is presented in the Table 5.14 below.
TABLE 5-14: LEAK FREQUENCIES FOR PROCESS EQUIPMENT
Frequency Equipment Type (per equipment item year) Flanges 8.8 X 10-5 Valves 2.3 X 10-4 Small Bore Fitting 4.7 X 10-4 Pressure Vessel 1.5 X 10-4 Pumps, centrifugal, double seal 1.7 X 10-2 Pumps, reciprocating, double seal 3.1 X 10-1 Compressors, centrifugal 1.4 X 10-2 Compressors, reciprocating 6.6 X 10-1 Source: HSE Hydrocarbon Release Database
Hence, with the proposed project span over a period of 2 years, frequency analysis for the process leaks from various process equipments are calculated as follows (Table 5.15)
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Table 5-15: Project Process Equipment’s Leak Frequencies
Frequency (A) Drilling Period Occurrence Frequency Equipment Type (per item year) (yrs) –(B) Frequency (A x B) Class
Flanges 8.8 X 10-5 2 1.76 X 10-4 Not Likely
Valves 2.3 X 10-4 2 4.60 X 10-4 Not Likely
Small Bore Fitting 4.7 X 10-4 2 0.94 X 10-3 Not Likely
Pressure Vessel 1.5 X 10-4 2 3.00 X 10-4 Not Likely
Pumps, centrifugal, 1.7 X 10-2 2 3.40 X 10-2 Occasional/Rare double seal Pumps, reciprocating, 3.1 X 10-1 2 6.20 X 10-1 Probable double seal Compressors, 1.4 X 10-2 2 2.80 X 10-2 Probable centrifugal Compressors, 6.6 X 10-1 2 1.32 Frequent reciprocating
Thus, as discussed above in most of the cases the frequency of occurrence of process leaks for the proposed project is either “Not Likely” or “Probable” with hydrocarbon release from reciprocating pumps and compressor is predicted to be “Frequent”. Further, taking into account that OIL plans to undertake periodic monitoring and preventive maintenance of such process equipment’s occurrence of such process leaks is likely to be less frequent.
Process Leaks – Consequence Analysis The potential consequences of a hydrocarbon leak from process equipments will depend, to a large extent on steps that can be taken to control or mitigate effect. There is considerable chance that a process leak might be ignited (either immediate or delayed) resulting in a fire or explosion. The following scenarios can occur if a hydrocarbon leak is ignited: Jet fires resulting from gas releases ignited early Pool fires and smoke plumes from ignited oil releases.
The evolution of a fire or explosion scenario as a result of a process leak can follow a complex chain of events which can be studied in further detail through a fault tree or what-if analysis. Fires or explosions resulting from ignition of hydrocarbon leaks can cause severe consequences, if it goes out of control and can damage equipment’s, including the drilling rig itself. The process leak consequences viz. jet fire and pool fire is likely to arise out of an ignition of the oil pool/vapour cloud formed. However, the same is dependent on the ignition probabilities accounted in relevant databases maintaining records of accidental events occurring over the years with respect to oil and gas industry. Review of the SINTEF
SENES/K-20197/ November 2013 160 Oil India Ltd. Pre Drill EIA for Drilling of 30 wells at Khagarijan Field database for major and minor process leaks indicated the following generic ignition probabilities (Table 5.16).
Table 5-16: Generic Ignition Probabilities
Gas Leak Oil Leak Release Rate Category Release Rate (kg/s) Probability Probability Minor <1 0.01 0.01 Major 1-50 0.07 0.03 Massive >50 0.30 0.08
Although records review of the OCS and Norwegian oil and gas installations indicated ignition delay for process leaks whereas the OCB/Technica (1988) revealed that for about 50% of the cases the ignition was delayed by about 5 minutes or more allowing escape of onsite crew and drilling personnel. However, as similar consequences viz. pool fire and jet fires are anticipated from process leaks as in blow outs, identical risk scenarios have been considered (in terms of oil and gas release rates) for leak consequence modeling based on professional judgment and analysis of process leak accident database. Hence, consequence modeling for process leaks/fires will be similar to that undertaken for well blow outs as discussed in the earlier section (Refer section 5.3.1). Risk Ranking – Process Leak Pool fire and Jet fire (Worst Case Scenario)
Likelihood ranking 2 Consequence ranking 4
Risk Ranking & Significance = 8 i.e. “Low”
Preventive and Mitigation Measures The preventive and mitigation measures for process leaks, fires and explosions will be implemented. Mitigative measures include the following: Provision for adequate leak and fire detection alarm systems; Installation of firefighting equipments, portable and fixed. Potential sources of ignition like welding/hot works, compressors, electrical equipment, compressors etc. be minimized, as far as practicable; Proper ventilation be arranged for in hazardous area to allow for inflammable gases to dissipate, when a release has occurred; Proper mechanisms like ESDs which can isolate leaks effectively need to be installed, in high risk process trains. Effective barriers in the form of blast walls, blast relief panels, etc. be installed to shield workers from high risk area where explosions may occur. Strict implementation of permit to work system and hazardous zone classification.
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Basic firefighting training to all working on the drilling rig. Installation of electrical equipment as per the hazardous zone classification.
5.3.3 Non-process fires/explosions Non-process fires are any fires and explosions that involve material other than hydrocarbons (e.g. electrical fires, diesel fires, accommodation fires, DG set fires, miscellaneous sources etc.). Most non-process fires are small incidents which can be managed within the facility using existing firefighting equipment’s. Such fires have however a higher frequency of occurrence compared to process fires and explosions as recorded by HSE database and World Offshore Accident Database (WOAD). Due to the absence of veritable data source recording non-process fire/explosion incidents for onshore installations the aforesaid databases for upstream oil and gas sector have been referred in an effort to analyze non-process fire/explosion risks with respect to the proposed project. Historically, few fatalities have been reported from non-process fires and most of them have been successfully managed at the installation level. Based on the WOAD 1996 statistical report, the average fatality rate for non-process fires is estimated at 10-3 platform year. Again, these fatalities have already been addressed under risks covered under personal accidents and need not be considered for fatalities due to non-process fires. However, as they have a higher probability to occur such incidents may cause inconveniences and come in the way of smooth operation of the drilling activities. The frequency of occurrence of fires due to possible non- process accident has listed in the Table 5.17 below:
TABLE 5-17: FREQUENCY OF OCCURRENCE - NON-PROCESS FIRES
Non-Process Accidents Frequency (per year)
Electrical fires 7.0 X 10-2
Diesel fires 9.2 X 10-3
Machinery fires 2.2 X 10-3
Miscellaneous fires 2.1 X 10-3 Source: WOAD As a result, though the damage potential is low, it is important to take appropriate safeguard measures to minimize their occurrence. Many of these measures can be implemented through the stipulation of simple work instructions and procedures. Risk Ranking for Non-Process Fires
Likelihood ranking 3 Consequence ranking 1
Risk Ranking & Significance = 3 i.e. “Low”
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Preventive and Mitigation Measures The preventive and mitigation measures for small non-process fires would be implemented by delineating appropriate operational procedures through the existing safety management system.
5.4 DISASTER MANAGEMENT PLAN
5.4.1 Objective The primary objective of the DMP is to provide a safe, timely, effective and coordinated response by the onsite Emergency Response Team (ERT), along with the other local and government agencies/departments to prevent or minimize any major emergencies that may arise from possible failures/risks viz. blow outs, oil spill, fire & explosion etc. associated with drilling. The main objectives of this plan are: To minimize the risk for human life, environment and common property resources, by means of an effective and efficient intervention; Protection of the environment; Protection of public safety; To initiate the early and efficient response throughout the utilization of all available resources.
5.4.2 Purpose The purpose of the DMP is to effectively manage and control the emergencies occurring during project operations. This DMP ensures, emergency response group is effective & adequate; clear roles and responsibilities of key personnel & support groups; availability and adequacy of emergency infrastructure & resources; and efficient emergency communication
5.4.3 Emergency Classification Due consideration is given to the severity of potential emergency situation that may arise as a result of storage tank as discussed in the Quantitative Risk Analysis (QRA) study. Not all emergency situations call for mobilization of same resources or emergency actions and therefore, the emergencies are classified into three levels depending on their severity and potential impact, so that appropriate emergency response procedures can be effectively implemented by the Oil India Emergency/Crisis Management Team. The emergency levels/tiers defined with respect to this project based on their severity have been discussed in
SENES/K-20197/ November 2013 163 Oil India Ltd. Pre Drill EIA for Drilling of 30 wells at Khagarijan Field the subsequent sections with 'decision tree' for emergency classification being depicted in Figure 5.3.
FIGURE 5-3: EMERGENCY CLASSIFICATION “DECISION TREE”
EMERGENCY
Activate Disaster Management Plan
Mobilization of equipment/human YES LEVEL 1 resources available onsite is sufficient EMERGENCY to contain the emergency
NO
Containment of emergency requires involvement of additional resources YES LEVEL 2 and local emergency responder group’s EMERGENCY viz. local police, fire brigade etc
NO
Management of emergency requires the YES LEVEL 3 involvement of District/State Disaster EMERGENCY Management Team
5.4.4 Level 1 - Emergency An event that can be dealt with by on-site/location personnel and resources; the event does not have any effect outside the site and external agencies are unlikely to be involved. There is unlikely to be danger to life, to the environment, or to Company assets or reputation. The Disaster Management Plan and relevant procedures are activated; the Site Head is notified.
5.4.5 Level 2 - Emergency It is an event which may be dealt by the OIL Emergency/Crisis Management Team but requires involvement of wider Company support and external services. The initial event may be “on-site”, having some effects outside the site or be “off-site”, and external emergency
SENES/K-20197/ November 2013 164 Oil India Ltd. Pre Drill EIA for Drilling of 30 wells at Khagarijan Field services will be involved. There is likely to be a danger to life, the environment, or company assets or reputation. The Disaster Management Plan and relevant procedures are activated; local administrative bodies and Emergency Response Groups including Oil India Corporate are notified.
5.4.6 Level 3 - Emergency It is a major event which requires the involvement of District or State Crisis Management Group. For Company this may result from insufficient local resources and/or because the incident has broader implications such as reputation, legal prosecution, financial loss etc. Under such circumstances, the Disaster Management Plan is activated; Oil India Corporate, District/State Administrative Authorities and other Emergency Response Groups are notified. The criterion for classification of various levels of emergencies and associated response has been presented in the Figure 5.4 below.
FIGURE 5-4: EMERGENCY RESPONSE LEVELS
Level Type Criteria for Classification Level 1 Small Minor medical or injury case requiring no external support Equipment damage without any significant impact on operation Minor fire without any personnel injury or plant damage Net negative financial impact of <1 crores. Small operational spills No potential impact on flora and fauna of identified eco-sensitive areas. Local stakeholder concern and public attention
Level 2 Medium Fire and explosion which requires external assistance Requires evacuation of injured personnel and locals through assistance from local emergency groups. Loss of corporate image and reputation Adverse impact on environmental sensitivities (if any) within a radius of 1km. Medium sized spills Net negative financial impact of 1 - 5crore Incident leading to multiples injuries or fatalities Level 3 Large Requires assistance from District/State emergency responding groups. Adverse impact on environmental sensitivities (if any) within a radius of >1km. Major oil spills State/nationwide media coverage Net negative financial loss of >5crore
5.4.7 OIL Emergency Response/Crisis Management Team OIL has in place an Emergency Response/Crisis Management Team (ERT) to respond to fire, blow-out, spills, accidents and technical emergencies. These teams will be made up from operations personnel, who can be called upon 24 hours a day, supported by senior
SENES/K-20197/ November 2013 165 Oil India Ltd. Pre Drill EIA for Drilling of 30 wells at Khagarijan Field management field personnel as and when required. The emergency response teams will receive specific training for their roles and exercise on a regular basis. Specific roles and responsibilities of the OIL ERT headed by the Chief Coordinator have been outlined below with the organizational structure being presented in Figure 5.5.
Chief Coordinator Declares Crisis/Emergency situations. Communicates with CMD/Ministry. State Govt. high officials and releases information’s to Press / Mass communications Media. Directs main Coordinators as deemed necessary arising out of Crisis situations.
Services Coordinator Coordinates for implementation of fire control measures. Provision of emergency communication. Maintenance and supply of essential services like Water, Electricity, Gas, Transport. Ensures provision of material, repair facilities at workshop. Provision of temporary accommodation, repair / Restore roads & Bridges, removal of debris etc.
Production Coordinator Assesses damages to production systems. Arranges for Isolation, Salvaging of the affected installation. Arranges for repairs and restoration of Crude Oil, Natural Gas, LPG production and supply.
Administrative & Welfare Coordinator Coordinates for provision and maintenance of security arrangements. Liaises with Police and District Civic authorities. Coordinates with HEAD (MS) & GM(ER) for Rescue, Shelter and Medical relief operations. Informs voluntary organizations to assist for rescue and relief operations. Maintains public relations.
Medical Relief Coordinator Arranges for first-aid at the site of incidence Arranges for Ambulance and Medical Services Organized Medical relief camp in Oil Hospital and arranges for extended services under Mutual Aid Scheme with the Neighboring Industries and Civil Hospitals.
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Employee Relations & Welfare Coordinator To participate in rescue and relief operations. To contact relatives of affected persons and provide Food/ Beverage etc. at relief camp. Contacts to Union Officials.
Safety & Environment Coordinator To liaise between the main Coordinators. To liaise with statutory Safety & Environment authorities i.e. Mines Safety Directorate, Petroleum & Explosive Safety Organisation, State/ Central Pollution Control Board, OISD etc. To liaise with members of mutual aid scheme i.e. BVFCL- Namup, IOC, (AOD) Digboi, AGCL- Duliajan, APL- Namrup, NEEPCO- Kathalguri, CIL Margherita, NTPS- Namrup.
Finance Coordinator To give financial support for all activities arranged by Main Coordinators.
Operation Group Coordinator To co-ordinate activities of Well control measures in case of impending blowout or blowout with or without fire. Coordinate with Oil and Natural Gas Corporation Limited for emergency support. To liaise with Services Coordinator for fire control measures and emergency standby duty.
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FIGURE 5-5: ORGANIZATIONAL STRUCTURE – OIL INDIA EMERGENCY RESPONSE TEAM
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5.4.8 Interface with Other Plans The Disaster Management Plan for the proposed project will be interfaced with the Tinsukia and Dibrugarh Disaster Management Plan prepared by the relevant District Disaster Management Authority (DDMA). The District Disaster Management Authority (DDMA) is an apex planning body and plays a major role in preparedness and mitigation. The district level response is coordinated under the guidance of the Deputy Commissioner, who acts as a District Disaster Manager. The District Disaster Management Authority (DDMA) for Tinsukia District has been formed to deal with any exigencies like natural calamity or man‐made structural disturbances viz. fire, explosion etc. A Disaster Management Committee also exists to assist the Deputy Commissioner in reviewing the threat of disasters, vulnerability of the district to such disasters and evaluating the preparedness. The District Disaster Response & Information Centre (Control Room), under the control of the Deputy Commissioner, will act as the Emergency Response Centre. It has been set up to monitor, co-ordinate and implement the action for disaster management. It works throughout the year and orders the various departments to work as per the directions during the disaster.
Communication Mechanism – District Level Emergencies/Disasters On the basis of reports from possible disaster/emergency site that involves a Level-3 response, or on the warning from the agencies competent to issue such a warning, or on the receipt of warning or alert from Emergency Operations Centre, the Deputy Commissioner will exercise powers and responsibilities of the District Disaster Manager. The information dissemination at times of emergency for Tinsukia District has been laid down as under: The Deputy Commissioner will be the nodal officer for this who will apprise the Addl. Deputy Commissioner, Project Officer (DM) and persons concerned, Circle Officers, Water Resource Dept., PWD (Roads) Dept. IWT Dept., Medical & Health Dept. through SMS and phone. Deputy Commissioner will give direction to BSNL of Tinsukia District to immediate arrangement for alternative phone connectivity in the control room of Deputy Commissioner’s Office. For any early warning reports received from North-East Space application Centre (NESAC), Umiam, Meghalaya, the same should be intimated to Executive Engineer, Water Resource, PWD State Roads / Rural Roads and Superintendant of Police, Addl. SP, SDO Civil Sadiya and Margherita and all Circle Officers. Circle officers will have village vulnerability map with them so that they can pass message to respective Gaon Buras / LR Staff and PRI members without fail. Superintendent of Police will accordingly inform Officers-in-Charge of Police Stations and In-Charge of Out Posts. Circle Officers will also keep contact with the representative members of vulnerable villages.
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6 Environmental Management Plan & Monitoring Framework This Environmental Management Plan and Monitoring Framework is a site specific document for the exploration and development of hydrocarbons that has been developed to ensure that OIL can implement the project in an environmentally conscious manner and where all contractors, understand the potential environmental risks arising out of the proposed project and take appropriate actions to properly manage such risk. This EMP will be an overview document that will guide environment management of all aspects of OIL’s activities within the Khagarijan Field. This EMP will be backed up by more specific Environmental Action Plans, Procedures and Bridging Documents with the progress of the well site preparation, drilling, well testing and site decommissioning activities. The EMP describes the actions to be adopted in terms of: National Policies and Regulations Best Practices and guides Local Environmental and Social Sensitivities
The Environment Policy of OIL is presented at Box 6.1.
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Box: 6.1: OIL Corporate Environment Policy
6.1 ENVIRONMENT MANAGEMENT PLANS The Environment Management Plan details out the mitigation measures to be implemented by both OIL and the Contractors during various stages of the exploratory, development and testing activity within the Khagarijan Field. The following environmental management plans
SENES/K-20197/ November 2013 171 Oil India Ltd. Pre Drill EIA for Drilling of 30 wells at Khagarijan Field have been formulated in line with the proposed project activities viz. site preparation, drilling, well testing and decommissioning Pollution Prevention and Abatement Plan Waste Management Plan Storm Water Management Plan Wildlife Management Plan Road Safety and Traffic Management Plan Occupational Health & Safety Management Plan
OIL will ensure communication and implementation of the aforesaid management plans prior to the commencement of site preparation and drilling operations in the field. In addition, the mitigation measures for social issues and concerns are also separately presented in this report. An Emergency Response Plan to address technological emergency situations viz. blow outs, fires, oil spill etc. etc. that may arise out of drilling operations has already been discussed in previous chapter. In cases, where there are possible overlaps, the plans have been cross- referenced to avoid repetition. Additional mitigation measures to ensure effective management of identified environmental aspects during various phases of the proposed project have been discussed under the aforesaid plans in the subsequent sections and summarized in Table 6.1 for ease of reference.
6.1.1 Pollution Prevention and Abatement Plan (PPAP) Scope The Pollution Prevention and Abatement Plan (PPAP) is applicable for and encompasses both construction and operational phase activities for the proposed project which has the potential to adversely impact ambient air and noise quality, surface and ground water quality and soil quality of the Khagarijan Field. Purpose The PPAP establishes specific measures and guidelines aimed at effectively addressing and mitigating the air, noise, water and soil quality impacts that may arise as result of well site preparation and access road construction/strengthening, drilling operations, well testing and decommissioning/site closure. The plan also details out roles and responsibilities of OIL and the contractors to ensure effective implementation of the plan.
Mitigation Measures & Strategies The following mitigation measures need to be adopted and implemented by OIL and its contractors during various phases of the proposed project to prevent and control air emissions (both point and fugitive), high noise generation, soil contamination and fertility loss, contamination and depletion of ground water resources and storm water discharge.
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A. Control of fugitive and point source emissions
Project Phase Mitigation measures
Construction Siting of well and borrow areas away from human settlement/habitation and sensitive receptors. Special care will be taken for Wells 2, 3, 4, 6, 8,9, 11, 13, 14, 17, 18, 22,23, 26, 27, 28 29 and 30 as they were located very close (less than 200 m) to human settlements (Dighalipathar, Hathigonda, Orangpati, Balijan Pani Era, Rahmoria, Genichuk, Nimbari, Balijan North TE colony, Jariguri, Panitola TE Colony, Captain Chawk etc.). Vehicles delivering raw materials like soil and fine aggregates will be covered to prevent fugitive emissions. Storage and handling of raw material and debris will be carefully managed to prevent generation of fugitive dust. Sprinkling of water on earthworks, material haulage and transportation routes on a regular basis during dry season. All vehicles, equipment and machinery used for construction will be subjected to preventive maintenance as per manufacturer norms. All vehicles utilized in transportation of raw material and personnel will have valid Pollution under Control Certificate (PUC). Vehicular exhaust will be complying with the CPCB specified emission norms for heavy diesel vehicles. The top soil generated from site clearance activities will be stored in designated area and stabilized to prevent fugitive dust emissions.
Drilling and well testing Flaring will be undertaken in accordance with the CPCB Guidelines for Discharge of Gaseous Emissions for Oil & Gas Extraction Industry. Locations of flare stack will be governed by the presence of habitation and sensitive receptors. Special care will be taken for Wells 2, 3, 4, 6, 8,9, 11, 13, 14, 17, 18, 22,23, 26, 27, 28 29 and 30 as they were located very close (less than 200 m) to human settlement. Duration of flaring will be minimized by careful planning; High combustion efficiency, smokeless flare/burner will be used. An efficient test flare burner head equipped with an appropriate combustion enhancement system will be selected to minimize incomplete combustion, black smoke, and hydrocarbon fallout. Volumes of hydrocarbons flared will be recorded. Exhausts of engines on the drilling rig diesel generators will be positioned at a sufficient height to ensure dispersal of exhaust emissions; engines will not be left running unnecessarily.
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Project Phase Mitigation measures
Preventive maintenance of DG sets will be undertaken as per manufacturers schedule to ensure compliance with CPCB specified generator exhaust. Decommissioning/Site Mitigation measures to address the air quality impacts resulting from Closure vehicular movement, operation of heavy construction machinery and material handling are similar to those discussed above
B. Control of Noise and Vibration
Project Phase Mitigation measures
Construction Selection and use of low noise generating equipment equipped with engineering controls viz. mufflers, silencers etc All vehicles utilized in transportation of raw material and personnel will have valid Pollution under Control Certificate (PUC) Periodic preventive maintenance of vehicles as per manufacturer’s schedule to ensure compliance with the vehicular noise limits specified by CPCB All high noise generating equipments will be identified and subjected to periodic preventive maintenance. No night time operation of vehicles and construction activities will be undertaken. Engines of vehicles and construction equipment will be turned off when not in use for long periods.
Drilling Siting of drilling rig and facilities away from sensitive receptors viz. schools, settlements etc. with all reasonable screening being utilized where necessary. Special care will be taken for Wells 2, 3, 4,5, 6, 8,9, 11, 13, 14, 15, 17, 18, 22,23, 26, 27, 28 29 and 30 as they were located very close (less than 250 m) to human settlement. Installing acoustic enclosures and muffler on engine exhaust of DG sets to ensure compliance with generator noise limits specified by CPCB. Setup effective noise barrier at the fence-line of the site; Restrict all noise generating operations ,except drilling, to daytime; Periodic monitoring of noise levels on site and nearby receptors to ensure compliance with Noise Pollution (Regulation & Control) Rules 2000.
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Project Phase Mitigation measures
Decommissioning/Site Management measures to address noise impacts with respect to operation Closure of heavy equipments/machinery and movement of vehicles during decommissioning/site closure phase are similar to those discussed in the “Construction Phase” of this section
C. Prevention and Control of Soil Quality Impacts
Project Phase Mitigation measures
Construction Minimize the felling of trees (at drill site located at forest) and removal of vegetation (drill sites homestead tea garden and tea estates) through proper and careful selection of site thereby reducing soil erosion. Site preparation and road strengthening/widening activities will be restricted within defined boundaries. Avoid construction activities during monsoon season as moist soil is most susceptible to compaction. Use appropriate machinery and/or protective boarding during top soil stripping to ensure minimum compaction. Debris and excavated material generated during construction activities will be stockpiled in designated areas onsite. No material will be disposed in adjacent land surrounding the site boundary. For cleared areas, retain top soil in stockpile where possible on perimeter of site for subsequent re-spreading onsite during restoration. Provide embankment all around the heap of excavated top soil and cover it with tarpaulin sheet to avoid erosion by the action of rains/strong winds. At well sites located at flood prone areas the top soil stockpile will be stored at areas higher to HFL to prevent washing down of the stockpile Install and maintain effective run-off controls, including silt traps, straw barriers etc. so as to minimize erosion. Drip trays to be used during vehicular/equipment maintenance and during refueling operations. In case of a spill, the spilled soil is to be removed and stored in hazardous waste storage area
Drilling All chemical and fuel storage areas will be designed considering HFL Fuel and chemical storage areas will be paved and properly bunded. Bunded areas will be designed to accommodate 110% of the volume
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Project Phase Mitigation measures of spilled material. Spill kits will be made available at all fuel and chemical storage areas. All spills/leaks contained, reported and cleaned up immediately. Drip pans/trays will be used in areas identified having spillage potential but not limited to drill rig engine; electric generator engine; pumps or other motors; maintenance areas; fuel transfer areas. In case of a spill, the spilled soil is to be removed and stored in hazardous waste storage area Management of drill cuttings, waste drilling mud, waste oil and domestic waste will be made in accordance with “Waste Management Plan” Decommissioning/Site Decommissioning at the end of project life/drilling will have some Closure adverse impacts in terms of increase in soil erosion and would require adequate mitigation measures to minimize any adverse impacts. The mitigation measures will be similar to those outlined for construction phase activities as discussed earlier.
D. Prevention and Control of Surface Water Quality Impacts
Project Phase Mitigation measures
Construction Minimize clearing and construction activities during monsoon season (as far as practicable). Construction work close to the streams or water bodies (at Wells 1, 5, 12, 14, 15, 19, 22, 23, 24, 28, 30) to be avoided during monsoon During site preparation and construction, surface water run-off will be managed through implementation of proper drainage system and silt trap and sedimentation tank onsite. Sediment filters and oil-water interceptor will be installed by the Contractor to intercept run-off and remove sediment before it enters water courses. Run-off discharges to natural drainage channels/water bodies to conform to CPCB Inland Water Discharge Standards. Regular inspection of surface water drainage/diversion system and sediment controls will be undertaken.
Drilling Run-off from vehicular wash and chemical storage areas will be channeled through closed drainage system provided with an oil- water separator prior to silt trap and sedimentation tank to disposal to nearby drainage channels/surface water bodies. Spill kits will be
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Project Phase Mitigation measures made available in these areas. Drip trays will be used during preventive maintenance of vehicles and machinery. Hazardous chemicals and fuel drum will be stored in bunded and lined area equipped with proper spill control equipment. Management of drill cuttings, waste drilling mud, waste oil and domestic waste will be made in accordance with “Waste Management Plan” Decommissioning/Site No significant impacts to surface water quality can be associated with Closure activities during decommissioning/site closure phase. Any possible impacts that may arise due to surface run-off will be mitigated in manner similar to that discussed during construction phase activities.
A. Prevention and Control of Ground Water Quality Impacts
Project Phase Mitigation measures
Construction No significant impact on the ground water quality can be associated with the construction phase activities
Drilling The wells will be sited at a sufficient distance away from an existing tube well or open well. Proper casing and cementing of well will be done to prevent contamination of sub-surface aquifers. Water based mud to be used as a drilling fluid for the proposed project Selection of low toxicity chemicals/additives in the preparation of water based mud. Periodic monitoring of ground water quality will be carried out for village wells located outside the project boundary to assess the level of ground water contamination, if any. Storage and disposal of drill cutting and waste mud to be made in accordance with “Solid & Hazardous Waste Management Plan” Decommissioning/Site No significant impacts to ground water quality can be associated with Closure activities during decommissioning/site closure phase
6.1.2 Waste Management Plan Scope The Waste Management Plan (WMP) is applicable for all process and non-process waste streams which are generated during various phases of OIL’s proposed drilling and testing of hydrocarbons in Khagarijan Field. The major waste streams covered under this plan includes
SENES/K-20197/ November 2013 177 Oil India Ltd. Pre Drill EIA for Drilling of 30 wells at Khagarijan Field drill cuttings, waste drilling mud, drilling wash water, kitchen waste and sewage. In addition, waste oil and lead acid batteries generated from the proposed project operations have also been dealt in this plan. Purpose The WMP establishes specific measures to ensure proper collection, storage, treatment and disposal of the identified process and non-process waste streams in accordance with the applicable national regulations and guidelines20 and also to ensure compliance with OIL’s corporate HSE Policy. The plan also outlines roles and responsibilities of both OIL and the contractors involved in the implementation of the plan. Mitigation Measures The following mitigation measures need to be adopted and implemented by OIL and its contractors for the major waste streams identified in the plan.
Waste Quantity Mitigation Measure
Drill Cuttings Approximately Drill cuttings separated from drilling fluid will be 3 290 m /well adequately washed and temporarily stored and disposed in an impervious pit lined by HDPE. Design aspects of the impervious waste disposal pit will be communicated/shared by OIL with Assam State Pollution Control Board (ASPCB). The drilling cuttings pit will be bunded and kept covered using tarpaulin sheets during monsoon. Periodic monitoring and analysis of drill cuttings will be undertaken to establish its nature and characteristics. The waste pit after it is filled up will be covered with impervious liner over which a thick layer of native top soil with proper top slope will be provided. Feasibility study for use of drill cuttings for lining or capping of landfill sites, or as a road construction material in consultation with nodal authorities Drilling waste mud Waste mud 5 Use of water based mud as the drilling fluid. 3 and wash water m /day Use of low toxicity chemicals for the preparation of Washwater 6.2 drilling fluid. m3/day Barite used in the preparation of drilling fluid shall not contain Hg>1mg/kg and Cd>3mg/kg Recycling of drilling mud will be ensured to the
20 “Guidelines for Disposal of Waste – CPCB Oil & Gas Extraction Industry Standard” – EPA Notification [GSR 176(E), April 1996] “Guidelines for disposal of Solid Waste, Drill Cuttings and Drilling Fluids for Offshore & Onshore Drilling Operation” –MoEF Notification, 30th August 2005
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Waste Quantity Mitigation Measure maximum extent possible. Temporary storage of drilling fluid and wash waste water will be done in an impervious pit lined with HDPE. The drilling fluid pit will be bunded to prevent water overflow during heavy monsoon. Disposal of drilling wash water will be achieved through necessary treatment through onsite Effluent Treatment Plant (ETP) to comply with the CPCB onshore effluent discharge standard for oil and gas industry. Kitchen Waste 10-20 kg/day The waste will be segregated and stored in designated waste bins. All such waste bins will be properly labeled and covered. The kitchen waste will be disposed in nearest municipal dumping site on a daily basis through approved waste handling contractors Waste oil/ Used oil As generated The hazardous waste (waste and used oil) will be managed in accordance with Hazardous Waste (Management, Handling & Transboundary Movement) Rules, 2008. The hazardous waste will be stored in properly labeled and covered bins located in paved and bunded area. Necessary spill prevention measures viz. spill kit will be made available at the hazardous material storage area Storage details of onsite hazardous waste generated will be maintained and periodically updated. Adequate care will be taken during storage and handling of such waste viz. use of proper PPEs by personnel The hazardous waste so stored (not more than 3 months) to be periodically sent to ASPCB registered used and/or waste oil recyclers/ facilities. Proper manifest as per HWMH rules to be maintained during storage, transportation and disposal of hazardous waste. Sewage 8 m3/day per The sewage generated will be treated in a combination well of septic tank and soak pit. Regular supervision will be undertaken for the domestic waste treatment system to report any overflows, leakage, foul odour etc.
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Waste Quantity Mitigation Measure
Lead Acid Batteries 2-3 batteries Will be recycled through the vendors supplying lead per well acid batteries as required under the Batteries (Management & Handling) Rules, 2001. Proper manifest will be maintained as per Batteries (Management & Handling) Rules, 2001. Recyclables viz. Depending on Proper segregation and storage of recyclable waste in paper, plastic, usage designated bins onsite. packaging waste etc. Recyclables will be periodically sold to local waste recyclers.
In addition to the management measures specified for the major waste stream, OIL will prepare and update periodically a waste management inventory of all waste streams identified for the proposed project. Necessary measure will also be taken by OIL to incorporate appropriate waste management and handling procedures in the contractor work document and conduct periodic training of personnel involved in waste handling onsite to ensure proper implementation of the WMP. In this regard, necessary inspection, record keeping, training program and monitoring procedures will be established by OIL and made operational to achieve proper management of all wastes generated on site.
6.1.3 Storm Water Management Plan Scope The Storm Water Management Plan (SWMP) refers to the proper management of surface run-off generated during monsoons for various phases of activities involved in the project. Purpose The purpose of Storm Water Management Plan (SWMP) is to ensure prevent and control any adverse impact of discharge of storm water from the well site and road widening/strengthening areas to nearby natural drainage channels and community water bodies. Proper management of storm water runoff will minimize damage to public and private property, reduce effects of development on land, control stream channel erosion, pollution and sediment deposition and also reduce local flooding. Mitigation Measures Pipe drainages will be provided for diversion roads constructed for the construction of new bridges and culverts. Storm water from all longitudinal and cross drainage works will be connected to the natural drainage courses. Necessary measures will be undertaken during construction phase to prevent earth and stone material from blocking cross drainage structures. Periodic cleaning will be undertaken to cross drainage structures and road drainage system to maintain uninterrupted storm water flow.
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Obstructions that may cause temporary flooding of local drainage channels, during construction phase will be removed. Oil traps and oil water separator will be used to separate oil from runoff water Sediment control measures in the form of silt traps and sedimentation tank will be provided to treat surface run-off before disposal
6.1.4 Wildlife Management Plan Scope The proposed drilling and testing of hydrocarbons in Khagarijan Field may impart potential impact on threatened animal species located within the Khagarijan Field. The likely impacts of the project activities on the ecological habitat have been addressed in a Wildlife Management Plan prepared to safeguard forest areas and their characteristic floral and faunal component. Purpose The purpose of Wildlife Management Plan is to minimize the impact on natural habitat (forest, river and wetland ecosystem) and control any adverse impact due to air and noise pollution from drilling and well testing activities, discharge of untreated waste water from drilling operation, storm water runoff from the well site and road widening/strengthening activities. The Management Plan details out the mitigation measures and strategies to be adopted by OIL and the Contractors during each phase of the project, at the same time establishing a monitoring network to investigate the effective implementation of the Management Plan.
Mitigation measures Care should be taken during finalization of drilling sites and location should avoid the ecologically sensitive areas like migratory route/ corridor, hoolock gibbon habitat. Permission from the National Board of Wildlife to be taken for proposed drill sites located within 10 km of Dibru-Saikhowa National Park and Padumoni & Bherjan segments of Bherjan-Borajan-Padumoni Wildlife Sanctuary. The drill site will be properly fenced (chain-linked) to avoid straying of any outsider as well as wildlife; No temporary electric supply connection line from the grid will be laid for the proposed project activity. All electric requirements will be supplied from the internal DG sets. Noise Levels at the drill site will be controlled through selection of low noise generating equipment and installation of sufficient engineering controls viz. mufflers, silencers etc. Movement of heavy vehicles will be restricted at night time, especially in access road within the forest area as most of the mammals movement occurred during night;
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The borrow areas and quarries will be located away from forests and ecologically sensitive areas. Care would be taken while disposal drill cutting & other drilling waste and discharge of waste water from the drilling site.
The following measures and strategies needs to be adopted to safeguard the natural habitat from the possible impacts resulting from the project and its related activities. An Environment Management Cell (EMC) will be developed for implementation of environmental mitigation & management plan. Forest personnel and veterinary doctor will be taken into the management cell for implementing the wildlife management plan. The environment cell would look after the following measures:
Any wild animal species if trapped during site development or operation of drilling would be released into suitable habitat; If elephant migrates into the drill site, then with the help of Forest Department personnel, the animal will be driven back into its suitable habitat; Proper monitoring of indicator species will be carried out and compared to baseline to understand any negative impacts; In case of any accidental injuries to any wild animal by any project related activity, the EMC’s Veterinary Doctor’s help will be taken All sightings of sensitive species in and around the project site will be reported and adequate steps will be taken with the help of forest personnel to reduce conflict between such animals and project activities or people working at site. The Environment Compliance Officer will hold training program for all the OIL employees and sub-contractor on the applicable practice and mitigation measures contained within the Wildlife Management Plan. Signage will be provided for the significant wildlife habitat, migration route and corridor within the block area and on the material transport route.
In addition, as discussed in Section 3.2,14 wells falls within 10km of both Dibru Saikhowa National Park as well as Bherjan Borjan Padumoni Wild life Sanctuary and 14 wells are located within 10km of only Dibru Saikhowa National Park and 1 well is situated within 10 km of only Bherjan Borjan Padumoni Wild Life Sanctuary. In view of all the existing sensitivities within the Khagarijan Field, OIL will prepare Site Specific Wildlife Management Plan and get approval for the same from National Board of Wildlife, Assam prior to the commencement of well site preparation.
6.1.5 Road Safety & Traffic Management Plan Scope The Road Safety & Traffic Management Plan is applicable to all operation pertaining to OIL and contractor vehicular movement viz. vehicle involved in the transportation of raw
SENES/K-20197/ November 2013 182 Oil India Ltd. Pre Drill EIA for Drilling of 30 wells at Khagarijan Field materials, project and contractor personnel, drilling rig and heavy equipment transportation to well site and decommissioning. Purpose The Road Safety & Traffic Management Plan outlines specific measures to be adopted and implemented by OIL to mitigate any potential impact on community health and safety that may arise out of movement of vehicles and transportation of drilling rig and heavy equipments during site preparation, drilling and decommissioning activities. Mitigation Measures Project vehicular movement involved in sourcing and transportation of borrow material will be restricted to defined access routes to be identified in consultation with locals and concerned authorities. Proper signage will be displayed at important traffic junctions along the predefined access routes to be used by construction and operational phase traffic. The signage will serve to prevent any diversion from designated routes and ensure proper speed limits are maintained near village residential areas. The condition of roads and bridges identified for movement of vehicles and drilling rig will be assessed by OIL to ensure their safe movement. Precautions will be taken to avoid damage to the public access routes including highways during vehicular movement. Safe and convenient passage for vehicles, pedestrians and livestock to and from side roads and property accesses connecting the project road will be provided. Work that affects the use of side roads and existing accesses will not be undertaken without providing adequate provisions. Parking of project vehicles along village access roads prohibited. Signposted parking facilities will be utilized for such purpose. Any road diversions and closure will be informed in advance to the villagers who are accessing the defined routes Traffic flows will be scheduled wherever practicable during period of increased commuter movement. Personnel will be deployed at major traffic intersection for control of traffic Clear signs, flagmen & signal will be set up at major traffic junctions and near sensitive receptors viz. primary schools in discussion with Gram Panchayat and local villagers. Movement of vehicles during night time will be restricted. Speed limits will be maintained by vehicles involved in transportation of raw material and drilling rig. Regular supervision will be done by contractor to control vehicular traffic movement along defined traffic routes particularly near identified sensitive receptors A Journey Management Plan will be formulated and implemented by the contractor to control construction and operational phase traffic.
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Routine maintenance of project vehicles will be ensured to prevent any abnormal emissions and high noise generation. Adequate training on traffic and road safety operations will be imparted to the drivers of project vehicles. Road safety awareness programs will be organized in coordination with concerned authorities to sensitize target groups viz. school children, commuters on traffic safety rules and signage.
In addition, OIL will ensure that all vehicles transporting hazardous substances (fuel oil, chemicals, etc.) will be properly labeled in accordance with the specifications of the Motor Vehicles Rules. The implementation of the Road Safety & Traffic Management Plan will be monitored which will include keeping track of vehicular densities on the NH 37 and other access and approach roads to the well sites.
6.1.6 Occupational Health & Safety Management Plan Scope The Occupation Health & Safety Management Plan (OHSMP) is applicable for all project operations which have the potential to adversely affect the health and safety of contractors’ workers and onsite OIL personnel. Purpose The Occupation Health & Safety Management Plan (OHSMP) has been formulated to address the occupational health and safety related impacts that may arise from proposed project activities viz. drilling and testing operation of construction machinery/equipments, storage and handling of fuel and chemicals, operation of drilling rig and associated equipment, during drilling and decommissioning/site closure. Mitigation Measures All machines to be used in the construction will conform to the relevant Indian Standards (IS) codes, will be kept in good working order, will be regularly inspected and properly maintained as per IS provisions and to the satisfaction of the site Engineer. Contractor workers involved in the handling of construction materials viz. borrow material, cement etc. will be provided with proper PPEs viz. safety boots, nose masks etc. No employee will be exposed to a noise level greater than 85 dB(A) for a duration of more than 8 hours per day. Provision of ear plugs, ear muffs etc. and rotation of workers operating near high noise generating areas. Hazardous and risky areas, installations, materials, safety measures, emergency exits, etc. shall be appropriately marked. All chemicals and hazardous materials storage container will be properly labeled and marked according to national and internationally recognized requirements and standards. Materials Safety Data Sheets (MSDS) or equivalent data/information in an
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easily understood language must be readily available to exposed workers and first-aid personnel. The workplace must be equipped with fire detectors, alarm systems and fire-fighting equipments. Equipments shall be periodically inspected and maintained to keep good working condition. Health problems of the workers will be taken care of by providing basic health care facilities through health centres temporarily set up for drilling base camp. The sewage system for the camp must be properly designed, built and operated so that no health hazard occurs. Adequate sanitation facilities will be provided onsite for the operational workforce both during construction and operational phase of the project. Garbage bins will be provided in the camp and regularly emptied and the garbage disposed off in a hygienic manner. Training programs will be organized for the operational workforce regarding proper usage of PPEs, handling and storage of fuels and chemicals etc. An Occupational Health Center is established at Duliajan to manage the occupational health issues.
6.1.7 Management of Social Issues and Concerns
Mitigation measure have been outlined to address project related social issues and concerns in order for OIL to take proactive steps and adopt best practices, which are sensitive to the socio-cultural setting of the region. The plans will include people residing in proximity to the proposed well sites and access routes, tea garden workers working close to the proposed well sites.
Providing Job Opportunities During site construction non technical jobs will be generated. Most of the people employed during this stage would be semi-skilled. People from adjoining areas especially given preference through local contractors according to the skill sets possessed.
Ensuring Public Safety Since the project involves the movement of heavy vehicles and machinery in the area, the issue of public safety of the villagers, especially children, tea garden workers is an important concern. During the drilling phase and for the rest of the project activities proper safety measures will be undertaken both for transportation as well as the other operations. The drill site would be fenced and gates would be constructed so that the children are refrained from straying into the site. The movement of traffic is also likely to disrupt access conditions of the inhabitants residing close to the approach road. The increase in traffic will have implications on their safety too, as well as create congestion, potential delays and inconvenience for pedestrians. The
SENES/K-20197/ November 2013 185 Oil India Ltd. Pre Drill EIA for Drilling of 30 wells at Khagarijan Field mitigative measures in this regard have been discussed in detail under the Road Safety & Traffic Management Plan (Section 6.1.5).
Common Property Resources During the project tenure there might be some sharing of resources viz. land, water, access routes etc. by the villagers and the contractor workforce. Prior to the commencement of the proposed activity, a consultation program will be conducted by OIL with the target groups and local authorities. The primary objective of such consultation will be to share with the concerned villagers/stakeholders the objective of the proposed project associated impacts and their mitigation. The movement of heavy vehicles and machinery might lead to conditions like disruption of electric wires and telephone wires in the site area and along transportation routes. These public utilities will be restored back to normal conditions, at the earliest. Fencing of the site will lead to in some cases the temporary loss of shortest foot track routes for the villagers to their agricultural fields. Consultation with villagers will be carried out in such cases to assist them in finding alternative foot track routes.
Corporate Social Responsibility From inception of its activities OIL has taken up various CSR initiatives in and around OIL's operational areas for the benefit of the residents. OIL's CSR Vision Statement envisages a minimum of 0.75% allocation of its net profit towards CSR. The various CSR activities include - Health - arranging more than 500 mobile health camps in the two districts of Tinsukia and Dibrugarh which include eye camps, cancer detection camps; OIL hospital being a part of the DOTS center for tuberculosis; School health programmes which includes free dental awareness examination camps and free check-ups of the students; universal immunization programme; donation to Assam Medical College, Guwahati Medical College, Sri Sanakaradeva Netralaya and Margherita Civil Hospital Education - OIL proclaims to have provided financial assistance to 350 institutions towards construction of school buildings, libraries, auditoriums, teacher's common room. Promotion of alternative livelihood - Oil had taken up programmes like Rupantar, Oil India Rural Development Society (OIRDS), Handicraft Training & Production Center (HPTC). All these programmes were launched with an intention towards addressing the growing problem of unemployment. Infrastructure - building of roads, rural electrification, erosion and flood control measures etc.
These initiatives needs to be intensified in the areas specific to operations proposed under this project. This is because of the fact that during the public consultations communities expressed that they are yet to benefit from OIL's CSR activities although OIL is in operation
SENES/K-20197/ November 2013 186 Oil India Ltd. Pre Drill EIA for Drilling of 30 wells at Khagarijan Field for such a long time in the region and therefore CSR activities would be able to appease the resentment that has been built up on OIL. The Environmental Management Plan Matrix for the proposed project has been presented in the Table 6.1.
6.2 EMP BUDGET The tentative budget for implementation of the environmental management plans has been provided below:
TABLE 6-1: TENTATIVE BUDGET FOR EMP IMPLEMENTATION
Sl. Particulars of Work Budget (in lakh No. Rs.) 1 Air Quality Management Plan a. Dust suppression through water sprinkling in the internal unpaved roads (@Rs. 10000 per month x 9 months x 1 year) 14.4 b. Maintenance of paved internal road and transport route (budgetary provision is included in operational cost of drilling) 0 c. Ambient Air Quality Monitoring -8 monitoring location x 2 weeks per location x 12 months (@ Rs. 5000 x 16 samples x 12 months ) 9.6 d. Stack emission monitoring (@ 5000 per sample x 30 sites x 4DG sets x twice during drilling) 12 2 Noise Monitoring a. Ambient Noise Monitoring – 30 locations, once in a month(@Rs. 2500 per location x 30 locations x 12 months) 9 b. Workplace noise monitoring -7 locations per well, twice during drilling (@Rs.2500 per location x 30 sites X 7 locations x 2 months) 10.5 3 Water Quality a. Surface Water Quality Monitoring (@ Rs. 5000 x 4 samples from natural drainages for four seasons, 2 from ETP and 1 from oil/water separator from 30 wells once each during drilling) 5.3 b. Ground Water Quality Monitoring (@ Rs. 5000 x 30 samples for 30 wells once during drilling) 1.5 4 Soil Quality Monitoring (@ Rs. 5000 x 30 samples x once each after decommissioning and for emergency sampling during accidental spill over during Site construction, drilling) 4.5 5 Road Safety & Traffic Management a. Signage in the transport route & its maintenance (Rs. 100,000 + Rs. 10,000 ) 1.1 b. Deployment of traffic personnel in sensitive area – 10 persons (@ Rs. 6000 per month x 12 months ) 7.2
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Sl. Particulars of Work Budget (in lakh No. Rs.) 6 Surface Runoff & Soil Erosion Control a. Two chamber sedimentation tank at each drill site (Budgetary provision is already included in the infrastructure development cost) 0 7 Municipal Solid Waste a. Provision of two chambered covered collection bins at well site – 30 nos 3 b. Transport arrangement of waste from well sites to dumping area 4 8 Hazardous waste management a. Construction of dedicated hazardous storage area and record maintenance (construction included under project cost; only maintenance included n this budget) 1 b. Drill Cutting, waste mud and washwater pits; HDPE lined (budgetary provision in operation cost of drilling) 0 9 Surface and Ground Water Protection and Management a. Surface runoff control measures for chemical storage area, fuel storage area (budgetary provision is already taken care in earlier section) 0 b. Paved /impervious storage area for chemical storage area, fuel & lubricant storage area (Budgetary provision is already included in the infrastructure development cost) 0 c. Domestic waste water treatment facility through septic tank & soak pits at the drill sites (budgetary provision in operation cost of drilling) 0 Commissioning and operational cost of ETP (commissioning cost 30 lakhs for 3 ETP; cost; operational cost Rs. 100000 per well X30 sites) 33 10 Wildlife Management Plan and its approval a. Preparation of wildlife management plan 20 b. Implementation of wildlife management plan 15 11 Occupational Health & Safety Management a. Provision of appropriate PPE to all workers and its maintenance (budgetary provision is included in operational cost of drilling) 0 b. Provision of drinking water, sanitation facility for all workers (budgetary provision is included in operational cost of drilling) 0 c Provision First aid facility (budgetary provision is included in operational cost of drilling) 0 d Provision of Ambulance facility OIL has its own ambulance facility) 0 e Regular health checkup facility provided by OIL for workers) 0 f Regular occupational health & safety training 2 Total Cost of Implementation of EMP 153.1 11 CSR Activity 2% of profit
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TABLE 6-2: ENVIRONMENTAL MANAGEMENT MATRIX
Sl. Activity Potential Impact Mitigation No A. Pre-drilling Activities A1 Siting of well site facility Potential adverse impact on environment in Selection of drill site taken into account of local environmental vulnerability the vicinity of the drill site Sufficient distance maintained in between site and nearest habitation Potential safety issues to local people related to drill site preparation and drilling operation A2 Procurement of land for well sites Loss of agricultural land and crop productivity Providing of compensation for standing crops and related facilities Loss of livelihood for affected communities Finalization of compensation package in consultation with local communities A3 Site preparation and road Loss of top soil and increase in soil erosion Minimal felling of trees and removal of vegetation through proper and careful selection strengthening/widening potential of site. Alternation in onsite drainage pattern Site preparation and road strengthening/widening activities to be restricted within defined boundaries. Avoidance of construction activities during monsoon season. Top soil stockpiles to be stabilized and stored in designated areas Provision of onsite drainage onsite. A4 Sourcing and transportation of raw Generation of fugitive emission Contractor to source raw materials from approved/licensed quarries. materials Community health and safety concerns Proper covering of raw material during transportation to be ensured Periodic water sprinkling along haulage routes near sensitive receptors Project vehicular movement be restricted to defined access routes to be identified in consultation with locals and concerned authorities. Proper signage be displayed at important traffic junctions along the predefined access routes. Night time movement of vehicles to be restricted A5 Operation of construction Fugitive emissions and high noise generation Selection of low noise generating equipment machinery/equipments Occupational health and safety concerns Installation of engineering controls viz. silencers, mufflers Rotation of workers operating in high noise generating areas Use of proper PPEs viz. ear plugs, ear muffs. Periodic preventive maintenance of machinery/equipments
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Sl. Activity Potential Impact Mitigation No A6 Transportation of drilling rig and Disruption of public utilities The public utilities viz. telephone and electrical wire to be restored to its original ancillaries Community health and safety concerns condition at the earliest. Movement of rig and heavy equipments to be carried out in accordance with the Road Safety & Traffic Management Plan formulated. A7 Discharge of surface run-off Increase in sediment load contributing to Provision of onsite sediment control measures viz. silt traps, sedimentation tank turbidity of receiving water bodies Construction work close to the streams or water bodies be avoided during monsoon Run-off discharges to natural drainage channels/water bodies made to conform to CPCB Inland Water Discharge Standards. B. Drilling and Testing B1 Physical presence of drilling rig and Temporary change in visual characteristics of Restoration of site to its original condition following decommissioning/site closure ancillaries the area B2 Operation of DG sets and machinery Air emissions and high noise generation Siting of drilling rig and facilities away from sensitive receptors and drilling Occupational health and safety concerns Installing acoustic enclosures and muffler on engine exhaust of DG sets Community discomfort Setting up effective noise barrier at the fence-line of the site; Exhausts of engines on the drilling rig diesel generators be positioned at a sufficient height Preventive maintenance of DG sets to be undertaken as per manufacturer’s schedule. B3 Casing & cementing of well Damage to subsurface aquifer Use of low toxicity chemicals Periodic monitoring of ground water quality be carried out for village wells located outside the project boundary to assess the level of ground water contamination, if any B4 Storage and disposal of drill cuttings, Soil and ground /surface water contamination Use of water based mud as the drilling fluid. mud and process wastewater Use of low toxicity chemicals for the preparation of drilling fluid. Recycling of drilling mud to be ensured to the maximum extent possible. Use of HDPE lined pit for disposal of drill cuttings, process wastewater Disposal of drill cuttings in accordance with CPCB and MoEF guidelines on management of drilling wastes B5 Discharge of surface run-off Soil and surface water contamination Run-off from vehicular wash and chemical storage areas be channeled through closed drainage system provided with an oil-water separator. Drip trays to be used during preventive maintenance of vehicles and machinery. Hazardous chemicals and fuel drum be stored in bunded and lined area equipped with
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Sl. Activity Potential Impact Mitigation No proper spill control equipment. Drill cuttings and mud pit be bunded and kept covered during monsoon. B6 Sewage treatment Occupational health problems of operational Sewage to be treated using a combination of septic and soak pits workforce The sewage treatment system (septic tank & soak pit) to be regularly monitored for any possible overflows, leakages etc. B7 Flaring during production testing and Air emission leading to discomfort to nearby Siting of flare stack considering nearest habitation and sensitive receptor. process upset communities Elevated flaring to be undertaken as per guidelines issued by CPCB for Oil & Gas Extraction Industry. Duration of flaring to be minimized by careful planning; C. Decommissioning/Site Closure C1 Dismantling of rig and associated High noise generation and fugitive emissions Rotation of workers operating in high noise generating areas facilities causing discomfort to locals Use of proper PPEs viz. ear plugs, ear muffs. C2 Transportation of drilling rig and Same as in B6 Same as in A6 ancillaries
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6.3 ENVIRONMENTAL MONITORING PROGRAM
Monitoring is one of the most important components of a management system. Continuous monitoring needs to be carried out for regulatory requirements, to monitor the environmental quality and to determine performance of proposed mitigation measures. Monitoring indicators have been developed for each of the activity considering the mitigation measures proposed. Indicators have been developed for ascertaining the environmental quality and performance of the EMP implementation through Environmental Quality Indicators (EQI’s) and Environmental Performance Indicators (EPI’s) respectively which focus not only on quantifying or indexing activity-environment interactions that may potentially impact the environment but at the same time also help in comparing different components of environmental quality against previously established baseline values. Monitoring results will be documented, analyzed and reported internally to Head–HSE of OIL. Monitoring requirements have been described in the following Table 6.2. Frequency of monitoring and responsibility of carrying out the monitoring have also been presented in the table below.
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TABLE 6-3: PROPOSED MONITORING REQUIREMENTS OF THE PROJECT A) Environmental Performance Monitoring EPI Environmental Performance Monitoring Parameter Location Period & Frequency Responsibility No. Indicator (EPI) A. Design & Planning A.1 Proximity of sensitive Distance between the drill site and sensitive Site Once in project lifecycle Civil supervisor environmental habitat environmental habitat A.2 Proximity of nearest habitation Distance between the drill site and nearest Site Once in project lifecycle Civil supervisor habitation A.3 Flood History HFL at site Site Once in project lifecycle Civil supervisor Return period of major floods A.4 Location and Size of Land Leased Number of land owners affected Site Once in project lifecycle Civil Supervisor Total area leased for drill site (Ha) A.5 Present Crop Cycle Crop period (in months) Site Once in project lifecycle Environmental Supervisor A.6 Approval / Authorization of Validity of the Approval / Authorization Quarry Once in project lifecycle Civil Supervisor quarries A.7 Land use Land use Type Quarry/ Borrow Once in project lifecycle Civil Supervisor Area A.8 Haul Routes Distance of quarry / borrow area from project site Quarry / Borrow Once in project lifecycle Civil Supervisor Condition of haul road Area
A.9 Borrowing practices % of contractors sensitized on best practices and Borrow Area During site planning HSE Manager & HSE Supervisor relevant EMP provisions
A.10 Undisrupted flow of water in Number of cross drainage structures planned to Site & Road Once in project lifecycle Civil Supervisor drainage channels number of actual stream crossings
B Approach Road & Site Development B.1 Topsoil Area occupied for topsoil storage/ Area planned Site Once during each site HSE Supervisor for topsoil storage preparation
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EPI Environmental Performance Monitoring Parameter Location Period & Frequency Responsibility No. Indicator (EPI) B.2 Local drainage pattern Number of Cross Drainage structures constructed Site & road Once in project lifecycle Civil Supervisor to actual number of cross drainage structures designed B.3 Fugitive emission of dust during Visual observation of dust in air by haziness Site & approach Daily during site HSE Supervisor with Vehicular / Civil site preparation roads preparation Contractors
B.4 Air emissions from vehicles and PM2..5, PM10, NOx, SO2, CO, HC, VOC based on Exhausts Once in project lifecycle HSE Supervisor with Civil Supervisor, machinery emission factors Visual observation of emissions (black signifying Drilling/Civil Supervisor through HSE more pollution) Daily Supervisor
% of vehicles possessing valid PUC Certificates
Drilling/Civil Supervisor through Drilling/Civil Supervisor through HSE Once in project life cycle Supervisor, Contractors operating vehicles B.5 Noise emissions from vehicles and Noise pressure level in dB(A) near noise sources Site & approach Daily during site HSE Supervisor machinery (5m) road preparation
B.6 Supervision of material transport Number of vehicles reported with overloaded Site Daily during site HSE Supervisor with Vehicular / Civil material / uncovered material preparation Contractors
B.7 Accident reporting Number of casualties / Number of fatalities Site & Haul During life cycle of HSE Supervisor Routes project B.8 Fugitive emission of dust during Visual observation of dust in air by haziness Near stockpiles Daily during the entire HSE Supervisor material handling and storage and storages project life-cycle C Drilling & Testing C.1 Gaseous pollutant emissions from Pollutant concentrations in gaseous emissions and DG Stack Monthly during drilling & HSE Supervisor through Drilling DG Set maintenance parameters (air, fuel filters & air- testing contractor fuel ratio) of DG sets influencing air emissions Visual observation of exhaust smoke Daily during drilling & characteristics testing
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EPI Environmental Performance Monitoring Parameter Location Period & Frequency Responsibility No. Indicator (EPI) C.2 Noise emission from DG Sets Noise pressure level in dB(A) Near noise Monthly during the entire HSE Supervisor through Drilling sources (5m) project life-cycle contractor
C.3 Noise emission from rig Noise pressure level in dB(A) On the rig floor Monthly during drilling HSE Supervisor through Drilling Near noise contractor sources (5m) Number of cases of workers not using PPE
Monthly during drilling Site
C.4 Accident reporting Number of casualties / Number of fatalities Site As and when accident HSE Supervisor through Drilling occurs contractor C.5 Spilled Chemicals/Oil Area of Spill / Quantity Spilled / Severity of Spill Site As and when spills occur HSE Supervisor through Drilling / Characterization of Spilled Substances for contractor Contaminants (Heavy Metals, Toxics, etc.)
C.6 Fugitive emission of cement dust Visual observation of cement dust in air by Near stockpiles Daily during the entire HSE Supervisor during handling and storage haziness and storages project life-cycle C.7 Runoff from temporary storage Supervision of functioning of conduits / drains, Site Fortnightly during drilling HSE Supervisor areas channels phase C.8 Emissions from Flaring Total CO, total hydrocarbon, Non-Methane Flare Stack As and when flaring HSE Supervisor through Drilling Hydrocarbons, NOx emission estimates based on occurs contractor emission factors C.9 Waste water quantity & quality Volume estimate At discharge Weekly during drilling HSE Supervisor through Drilling (Process water viz. rig wash, point contractor formation water etc) CPCB General discharge parameters and Oil & Quarterly during drilling Gas Extraction Industry Standards C.10 Storm water/wash down water CPCB General discharge parameters and Oil & At discharge Depending on generation HSE Supervisor through Drilling discharge Gas Extraction Industry Standards point particularly during contractor monsoon C.11 Drill cutting storage and disposal Total volume generated At storage Once during drilling HSE Supervisor through Drilling location period contractor Concentration of hazardous constituents as per Hazardous Waste Management and Handling
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EPI Environmental Performance Monitoring Parameter Location Period & Frequency Responsibility No. Indicator (EPI) Rules
CPCB Onshore discharge standards for Oil & Gas Extraction Industry D Decommissioning/ Site Closure D.1 Noise pressure level in dB(A) Near noise sources (5m) Site & Approach Once per site HSE Supervisor through Drilling & Civil road contractor
D.2 Air emissions from vehicles PM10, PM2.5, NOx, SO2, CO, HC based on Exhausts Once in project lifecycle HSE Supervisor through Vehicle/Civil emission factors Daily contractor Visual observation of emissions (black signifying more pollution) D.3 Fugitive emission of dust during Visual observation of dust in air by haziness Near stockpiles Daily during the entire HSE Supervisor transport of drilling facilities and storages activity D.4 Site restoration Visual observation of : Site Daily during Civil Supervisor with HSE Supervisor Clearing of decommissioning waste decommissioning Leveling of site Relaying of top soil Regeneration of top soil
B) Environmental Quality Monitoring
EQI Environmental Quality Indicator Monitoring Parameter Location Period & Frequency Responsibility No (EQI) A Approach Road & Site Development A1 Soil Fertility Fertility parameters like pH, NPK ratio, Total Site & adjacent areas Once before site preparation HSE Supervisor Carbon, etc. A2 Quality of water Analysis of Parameters as per CPCB Use-class Natural drainage channel Monthly during site and HSE Supervisor receiving run-off discharges road works
A4 Ambient Air Quality Measurement of PM10, PM2.5, NOx, SO2, CO, At Surrounding receptor Monthly during site and HSE Supervisor HC using ambient air sampler points road works
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EQI Environmental Quality Indicator Monitoring Parameter Location Period & Frequency Responsibility No (EQI) A5 Ambient noise quality Hearing / perception At surrounding receptor Daily site and road works HSE Supervisor Measurement of Noise Pressure Level in dB(A) points Monthly site and road works A6 Soil Contamination Analysis for suite of contaminants (heavy Site, adjacent areas and In event of spills over an HSE Supervisor metals, TPH, organics, pesticides). Waste disposal site area of 10 sq.m B Drilling & Testing
B1 Ambient Air Quality Measurement of PM10, PM2.5, NOx, SO2, CO, At Surrounding receptor Monthly during drilling and HSE Supervisor HC , using ambient air sampler points testing B2 Ambient noise quality Hearing / perception At surrounding receptor Daily during drilling and HSE Supervisor Measurement of Noise Pressure Level in dB(A) points testing Monthly during drilling and testing B3 Groundwater Quality Analysis of Parameters as per IS:10500 Nearby wells Once during drilling HSE Supervisor
B4 Soil Contamination Analysis for suite of contaminants (heavy Site, adjacent areas and In event of spills over an HSE Supervisor metals, TPH, organics, pesticides). Waste disposal site area of 10 sq.m B5 Quality of water Analysis of Parameters as per CPCB Use-class Natural drainage channel Monthly during drilling & HSE Supervisor receiving run-off discharges testing C Decommissioning / Closure
C1 Ambient noise quality Hearing / perception At surrounding receptor Daily during HSE Supervisor Measurement of Noise Pressure Level in dB(A) points decommissioning Monthly during decommissioning C2 Quality of water Analysis of Parameters as per CPCB Use-class Natural drainage channel Once after HSE Supervisor receiving run-off discharges decommissioning
C3 Ambient Air Quality Measurement of PM10, PM2.5, NOx, SO2, CO, At Surrounding receptor Monthly during HSE Supervisor HC , using ambient air sampler points decommissioning C4 Soil Fertility Fertility parameters like pH, NPK ratio, Total Site & adjacent areas Once after site restoration HSE Supervisor Carbon, etc.
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7 Disclosure of Consultants
SENES Consultants India Private Limited (SENES India) is a professionally managed, fast growing, wholly owned subsidiary of SENES Consultants Limited (SENES), Canada. SENES specializes in the fields of energy, nuclear, environmental and social sciences with offices spread across Canada, the United States, South America and India. SENES has been operational in India for more than seven years having Head Office in New Delhi with branch offices in Kolkata, Hyderabad and Mumbai with all supportive infrastructure necessary for project implementation. SENES India has accumulated a wide body of knowledge from its National and International Oil and Gas experience worldwide, including the EIAs for upstream oil & gas projects for Ensearch Petroleum in Jordan, Premier Oil in Assam, Geopetrol in Andhra Pradesh, Eni India in Andaman Sea, ONGC in Assam, Mizoram, Andhra Pradesh Oil India in Assam Cairn Energy in Rajasthan and Gujarat, British Petroleum in West Bengal etc. SENES India was responsible for carrying out the Pre-Drill EIA study and EMP of Exploration, Development and Testing of 30 wells in Khagarijan Oil Gas Field, District Dibrugarh and Tinsukia. The team deployed for the proposed project is provided below: Salil Das: EIA Coordinator Mangesh Dakhore: Risk Assessment Expert Dhritiman Ray: Water Quality Expert Avinandan Taron :Socioeconomic Expert Abhishek Roy Goswami: Ecology and Biodiversity Expert Indrani Ghosh: Air and Noise Quality Expert Subhradeb Pramanik: Risk Assessment Specialist Saumabha Bhattacharya: Environmental Specialist Sk. Nasiruddin Rahman: GIS and Mapping Specialist
The EIA report preparation have been undertaken in compliance with approved MoEF ToR and the information and content provided in the report is factually correct for the purpose and objective for such study undertaken. SENES has already obtained QCI Accreditation under the QCI-NABET Scheme for Accreditation of EIA Consultant Organizations vide certificate no: NABET/ EIA/ 1013/043 dated 9th October 2010. The QCI/NABET accreditation certification is provided in the following page.
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