EIA Studies for Exploratory drilling at Pre-NELP Block AA-ONJ/2
DRAFT EIA/EMP REPORT
M/s Oil and Natural Gas Corporation Ltd.
EIA Studies for Pre-NELP Block AA-
ONJ/2 (for Drilling 9 Exploratory Wells)
For on and behalf of SENES Consultants India Ltd
Approved by Mr. Salil Das Signed by
Position held NABET-QCI Accredited EIA Coordinator for Offshore & Onshore Oil and Gas Exploration Development and Production Date December 10, 2013
The EIA report preparation have been undertaken in compliance with approved ToR issued by the MoEF vide letter no. J11011/91/2012-IAII (I) dated 13th July, 2012. Information and content provided in the report is factually correct for the purpose and objective of the study .
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Abbreviation
ALARP As Low As Reasonably Practicable
BOD Biological Oxygen Demand
BOP Blow out Preventor
Block Khoraghat Extension ML Block
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 Group Gathering 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
KLD Kilo Liter per Day
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KW Kilo Watt
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
ONGC Oil and Natural Gas Corporation 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
SENES/K-20200/December 2013 d ONGC EIA Studies for Exploratory drilling at Pre-NELP Block AA-ONJ/2
Table of Contents Executive Summary ...... i 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 ...... 7 2.1 Overview ...... 7 2.2 Objectives and Benefits of Proposed Exploratory Drilling Activities ...... 7 2.2.1 Project Objectives ...... 7 2.2.2 Project Benefits ...... 7 2.3 AA-ONJ/2 Field Location & Description ...... 7 2.3.1 Location ...... 7 2.3.2 Accessibility ...... 8 2.4 AA-ONJ/2 Block ...... 12 2.4.1 Environmental Settings of the Block ...... 12 2.4.2 Existing Activity in Oil Field ...... 15 2.4.3 Environmental Compliance ...... 15 2.5 Well Locations and Environmental Settings...... 15 2.5.1 Location of Wells ...... 15 2.5.2 Salient Features of the Wells ...... 15 2.5.3 Environmental Settings ...... 18 2.6 Project Activities And Schedule ...... 36 2.6.1 Pre-drilling Activity ...... 36 2.6.2 Drilling Activity ...... 40 2.6.3 Well Decommissioning ...... 45 2.7 Utilities & Resource Requirements ...... 46 2.7.1 Power Supply ...... 46 2.7.2 Water Consumption and Supply ...... 46 2.7.3 Fuel Consumption and Storage ...... 48 2.7.4 Manpower / Employment ...... 48 2.8 Pollution Sources and Characterization ...... 48 2.8.1 Noise and Vibrations...... 48 2.8.2 Air Emissions ...... 49
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2.8.3 Waste water Treatment and Disposal ...... 49 2.8.4 Generation, Treatment and Disposal of Solid Waste (Hazardous and Non- Hazardous) ...... 50 2.9 Drilling Hazards ...... 51 2.10 Project Cost ...... 51 2.11 HSE Policy ...... 51 3 Description of the Environment ...... 52 3.1 Physical Environment ...... 52 3.1.1 Climate & Meteorology ...... 52 3.1.2 Ambient Air Quality ...... 54 3.1.3 Ambient Noise Quality ...... 58 3.1.4 Physiography and Geology ...... 61 3.1.5 Hydrogeology ...... 62 3.1.6 Ground Water Quality...... 63 3.1.7 Watershed and Drainage ...... 69 3.1.8 Surface water quality ...... 72 3.1.9 Land-Use ...... 74 3.1.10 Soil Quality ...... 76 3.1.11 Natural Hazards ...... 80 3.2 Biological Environment ...... 84 3.2.1 Introduction ...... 84 3.2.2 Methodology ...... 84 3.3 Terrestrial Ecosystem...... 86 3.3.1 Forest Resources ...... 86 3.3.2 Forest Land for Proposed Activity ...... 86 3.3.3 Vegetation Types ...... 87 3.3.4 Floral Diversity ...... 88 3.3.5 Endemic, Threatened & Endangered Floral Species ...... 88 3.3.6 Wildlife Habitat ...... 88 3.3.7 Faunal Diversity ...... 93 3.3.8 Endemic, Endangered & Threatened Fauna ...... 93 3.4 Aquatic Ecosystem...... 94 3.4.1 Aquatic Habitat ...... 94 3.4.2 Macrophytes ...... 94 3.4.3 Fishes & Fisheries ...... 94 3.4.4 Amphibia...... 94
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3.4.5 Aquatic Birds ...... 94 3.4.6 Endemic, Threatened & Endangered Species ...... 94 3.5 Agricultural Diversity ...... 94 3.6 Livestock ...... 95 3.7 Socioeconomic Environment ...... 95 3.7.1 Methodology ...... 96 3.7.2 General Socioeconomic Profile ...... 97 3.7.3 Demographic Profile ...... 99 3.7.4 Socioeconomic Infrastructure ...... 101 3.8 Cultural and historical sites ...... 103 4 Environmental Impact Assessment ...... 104 4.1 Impact Assessment Methodology ...... 104 4.1.1 Impact Criteria and Ranking ...... 104 4.1.2 Impact Significance ...... 105 4.2 Impact Assessment...... 108 4.2.1 Visual Impacts & Aesthetics ...... 108 4.2.2 Impacts on Air Quality...... 109 4.2.3 Impact on Noise Quality ...... 116 4.2.4 Potential Impact Transport and Traffic ...... 118 4.2.5 Potential Impact on Land Use ...... 119 4.2.6 Impact on Soil Quality ...... 119 4.2.7 Impact on Topography & Drainage ...... 121 4.2.8 Impact on Surface Water Quality ...... 122 4.2.9 Impact on Hydrogeology & Ground Water Quality ...... 124 4.2.10 Impact on Biological Environment ...... 124 4.2.11 Impact on Socioeconomic Environment ...... 126 4.2.12 Impact on Occupational Health and Safety ...... 129 5 Quantitative Risk Assessment (QRA) ...... 131 5.1 Objective of the QRA Study ...... 131 5.2 Risk Assessment Methodology ...... 132 5.2.1 Hazard Identification ...... 133 5.2.2 Frequency Analysis ...... 134 5.2.3 Consequence Analysis ...... 135 5.2.4 Risk Evaluation ...... 136 5.3 Risk Assessment of Identified Project Hazards ...... 137
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5.3.1 Blow Outs/Loss of Well Control ...... 138 5.3.2 Process Leaks/Fires ...... 167 5.3.3 Non-process fires/explosions ...... 170 5.4 Disaster Management Plan ...... 171 5.4.1 Objective ...... 171 5.4.2 Purpose ...... 171 5.4.3 Emergency Classification ...... 171 5.4.4 Level 1 - Emergency ...... 172 5.4.5 Level 2 - Emergency ...... 173 5.4.6 Level 3 - Emergency ...... 173 5.4.7 ONGC Disaster Management Plan ...... 174 6 Environmental Management Plan & Monitoring Framework ...... 183 6.1 Environment Management Plans ...... 185 6.1.1 Pollution Prevention and Abatement Plan (PPAP) ...... 185 6.1.2 Waste Management Plan...... 190 6.1.3 Storm Water Management Plan ...... 195 6.1.4 Site Closure Plan ...... 195 6.1.5 Wildlife Management Plan ...... 197 6.1.6 Road Safety & Traffic Management Plan ...... 199 6.1.7 Occupational Health & Safety Management Plan ...... 200 6.1.8 Management of Social Issues and Concerns ...... 201 6.2 EMP Budget ...... 202 6.3 Environmental Monitoring Program ...... 208 7 Disclosure of Consultants ...... 215
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List of Tables
Table 1-1: Compliance to MoEF ToR ...... 3 Table 2-1: Geo-coordinate of Block Boundary ...... 8 Table 2-2: Co-ordinates of Tentative Well Locations ...... 15 Table 2-3: Salient Features of a Typical Exploratory Well ...... 16 Table 2-4: Location of Exploratory Drill Site With Respect to Type of Land ...... 37 Table 2-5: Water Requirement Per Well ...... 46 Table 2-6: Construction Equipment Noise Level ...... 48 Table 2-7: Drilling Rig and Equipment Noise Level ...... 49 Table 2-8: Liquid Wastes Generated during Drilling and their Disposal ...... 50 Table 2-9: Waste Streams Generated during Drilling and Their Disposal ...... 50 Table 3-1: Average Hydrocarbon and VOC Monitoring Data ...... 58 Table 3-2: Groundwater monitoring Results ...... 66 Table 3-3: Distance of Well Sites from nearest river ...... 69 Table 3-4: Surface Water Quality Results ...... 73 Table 3-5: Soil Analysis Results ...... 79 Table 3-6: Significant Earthquakes in Assam ...... 81 Table 3-7: Flood history of Assam ...... 81 Table 3-8: location of exploratory wells in flood prone area...... 82 Table 3-9: Scheduled Animal Species in the Study Area ...... 93 Table 3-10: List of the study area villages in the AA-ONJ/2 Block ...... 99 Table 3-11: medical Infrastructure in Sonai and Lakhipur Block ...... 101 Table 3-12: Educational Facilities of districts coming under aa-onj/2 block ...... 102 Table 4-1: Impact Prediction Criteria ...... 105 Table 4-2: Criteria based Significance of Impacts ...... 106 Table 4-3: Impact Identification Matrix ...... 107 Table 4-4: Input Parameters Considered for Monitoring ...... 110 Table 4-5: Predicted GLCs for Air Pollutants ...... 111 Table 4-6: Impact Significance Matrix (with mitigation) ...... 130 Table 5-1: Frequency Categories And Criteria ...... 135 Table 5-2: Severity Categories and Criteria ...... 136 Table 5-3: Risk Matrix ...... 137 Table 5-4: Risk Criteria and Action Requirements...... 137 Table 5-5: Blow Out Cause Distribution for Failures during Drilling Operations ...... 140 Table 5-6: Pool Fire Modeling Scenarios ...... 143
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Table 5-7: Pool Fire Diameter & Steady State Burning Area ...... 144 Table 5-8: Distance to Thermal Radiation Threshold Levels ...... 154 Table 5-9: Natural Gas Release Modeling Scenarios ...... 155 Table 5-10: Zone of Flammable Vapour Cloud – Natural Gas Release Scenarios ...... 165 Table 5-11: Pool Diameter for Oil Spill Risk Scenarios...... 166 Table 5-12: Leak Frequencies for Process Equipment ...... 167 Table 5-13: Project Process Equipment’s Leak Frequencies ...... 168 Table 5-14: Generic Ignition Probabilities ...... 169 Table 5-15: Frequency of Occurrence - Non-Process Fires ...... 170 Table 6-1: Tentative Budget for EMP Implementation ...... 202 Table 6-2: Environmental Management Matrix ...... 205 Table 6-3: Proposed Monitoring Requirements of the Project ...... 209
List of Figures
Figure 2-1: Regional Setting Map of AA-ONJ/2 Block ...... 9 Figure 2-2: AA-ONJ/2 Block Location Map on Toposheet ...... 10 Figure 2-3: AA-ONJ/2 Block Accessibility Map ...... 11 Figure 2-4: Environmental Settings of AA-ONJ/2 Block...... 14 Figure 2-5: Location of Proposed Wells on Satellite imagery ...... 17 Figure 2-6: Land use of RBK-1 ...... 19 Figure 2-7: Land use map of RBK-2 ...... 21 Figure 2-8: Land Use map of RPAA ...... 23 Figure 2-9: Land Use Map of RBK-3 ...... 25 Figure 2-10: Land Use Map of RLBK-1...... 27 Figure 2-11: Land Use Map of RTDN-1 ...... 29 Figure 2-12: Land Use Map of RJDR ...... 31 Figure 2-13: Land Use Map of RTNG-1 ...... 33 Figure 2-14: Land Use Map of RTDN-2 ...... 35 Figure 2-15: Typical Drilling Rig Configuration...... 41 Figure 2-16: Drilling Waste Management System ...... 43 Figure 2-17: Typical Drilling Fluid Circulation System...... 44 Figure 2-18: Water Balance Diagram ...... 47 Figure 3-1: Wind Rose Diagram for Pre-Monsoon Season ...... 54 Figure 3-2: wind class frequency distribution ...... 54
Figure 3-3: Average PM 10 Values at the Monitoring Locations ...... 56
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Figure 3-4: Average NO2 Values at the Monitoring Locations ...... 56
Figure 3-5: Average SO2 values at the Monitoring Location ...... 57 Figure 3-6: Day and Night Time Equivalent Noise Levels ...... 59 Figure 3-7: Location of Air, Noise and Meteorology Monitoring Locations within the AA-ONJ/2 block ...... 60 Figure 3-8: Location of Groundwater, Surface Water and Soil Monitoring Locations within the AA-ONJ/2 Block ...... 68 Figure 3-9: Drainage and Watershed map ...... 71 Figure 3-10: Percentage Land use Distribution of Study Area ...... 74 Figure 3-11: Land Use Map of AA-ONJ/2 BLOCK ...... 75 Figure 3-12: Seismic Zone Map of India ...... 80 Figure 3-13: Wells located at the Flood Prone Zones ...... 83 Figure 3-14: Ecological Sensitivity Map ...... 90 Figure 3-15: Hoolock Gibbon Habitat in the State of Manipur & Mizoram ...... 92
Figure 4-1: Predicted NO2 Concentration Plot (2 X 750 KW DG Set) ...... 112
Figure 4-2: Predicted PM Concentration Plot (2 X 750 KW DG Set) ...... 113
Figure 4-3: Predicted SO2 Concentration Plot (3 X 750KW DG Set) ...... 114 Figure 4-4: Predicted HC Concentration Plot (3 X 750 KW DG Set) ...... 115 Figure 4-5: Noise Attenuation Plot ...... 118 Figure 5-1: Risk Assessment Methodology ...... 133 Figure 5-2: Blow Out Frequencies in Oil & Gas Industry ...... 141 Figure 5-3: Ignition Probability Vs Release Rate ...... 142 Figure 5-4: RBK-1 Well Site - Pool Fire Risk Contour Map ...... 145 Figure 5-5: RBK-2 Well Site - Pool Fire Risk Contour Map ...... 146 Figure 5-6: RPAA Well Site - Pool Fire Risk Contour Map ...... 147 Figure 5-7: RBK-3 Well Site - Pool Fire Risk Contour Map ...... 148 Figure 5-8: RLBK-1 Well Site - Pool Fire Risk Contour Map ...... 149 Figure 5-9: RTDN-1 Well Site - Pool Fire Risk Contour Map ...... 150 Figure 5-10: RJDR Well Site - Pool Fire Risk Contour Map ...... 151 Figure 5-11: RTNG-1 Well Site - Pool Fire Risk Contour Map...... 152 Figure 5-12: RTDN-2 Well Site - Pool Fire Risk Contour Map...... 153 Figure 5-13: RBK-1 Well Site – Risk Contour Map for Natural Gas Release ...... 156 Figure 5-14: RBK-2 Well Site – Risk Contour Map for Natural Gas Release ...... 157 Figure 5-15: RPAA Well Site – Risk Contour Map for Natural Gas Release ...... 158 Figure 5-16: RBK-3 Well Site – Risk Contour Map for Natural Gas Release ...... 159 Figure 5-17: RLBK-1 Well Site – Risk Contour Map for Natural Gas Release...... 160
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Figure 5-18: RTDN-1 Well Site – Risk Contour Map for Natural Gas Release ...... 161 Figure 5-19: RJDR Well Site – Risk Contour Map for Natural Gas Release ...... 162 Figure 5-20: RTNG-1 Well Site – Risk Contour Map for Natural Gas Release ...... 163 Figure 5-21: RTDN-2 Well Site – Risk Contour Map for Natural Gas Release ...... 164 Figure 5-22: Emergency Classification “Decision Tree” ...... 172 Figure 5-23: Emergency Response Levels ...... 173 Figure 5-24: ONGC On-Site Disaster Management Team Profile ...... 175 Figure 6-1: Environment Management Measures at Drill Site ...... 194
List of Photos
Photo 2-1: Nagakhal flowing adjacent to the Proposed Drill Site (RTDN-1) ...... 13 Photo 2-2: Rupai Bali Anua (RBK-2) ...... 13 Photo 2-3: Jiri River near Latingkhal Village, Manipur (RJDR)...... 13 Photo 2-4: Land use type adjoining the drill site, Assam (RTDN-1) ...... 13 Photo 2-5: Access Road to Exploratory Drill Site, Manipur (RJDR) ...... 13 Photo 2-6: Settlement at Telka Tea Estate Village, Assam (RBK-3) ...... 13 Photo 2-7: Proposed Exploratory Drill Site (RBK-1) ...... 18 Photo 2-8: Approach Road to Drill site (RBK-1) ...... 18 Photo 2-9: Proposed Exploratory Drill Site (RBK-2) ...... 20 Photo 2-10: Settlement near Drill Site (RBK-2) ...... 20 Photo 2-11: Proposed Exploratory Drill Site located on Forest Land (RPAA) ...... 22 Photo 2-12: Public utilities present near Drill Site (RPAA) ...... 22 Photo 2-13: Proposed Exploratory Drill Site (RLBK-1) ...... 26 Photo 2-14: Approach Road to Drill Site (RLBK-1) ...... 26 Photo 2-15: Proposed Exploratory Drill Site (RTDN-1) ...... 28 Photo 2-16: Approach Road to Drill Site (RTDN-1) ...... 28 Photo 2-17: Proposed Exploratory Drill Site (RJDR)...... 30 Photo 2-18: Approach Road to Drill Site (RJDR) ...... 30 Photo 2-19: Proposed Exploratory Drill Site (RTDN-2) ...... 34 Photo 2-20: Access Road to Drill Site (RTDN-2) ...... 34 Photo 3-1: Air Monitoring near Karkat Basti ...... 57 Photo 3-2: Groundwater sampling at Pabda Basti ...... 65 Photo 3-3: Groundwater sampling at Majhigram LP School ...... 65 Photo 3-4: Rukni River ...... 70
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Photo 3-5: Jiri River ...... 70 Photo 3-6: Sonai River ...... 70 Photo 3-7: Barak River ...... 70 Photo 3-8: Surface water sampling from Upstream of Barak River ...... 74 Photo 3-9: Surface water sampling from Rukni River...... 74 Photo 3-10: Soil sampling from Agricultural Land near Bhitor Narayanpur ...... 80 Photo 3-11: Soil sampling from Agricultural Land near Pabda Basti ...... 80
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Executive Summary
Introduction The Pre-NELP Block AA-ONJ/2 was awarded to ONGC (100%PI) for operation by Government of India (GoI) vides letter no. 0-19025/1712009-ONG-D-V dated 15.03.2011. During the current program, ONGC is planning to drill 9 exploratory wells in AA-ONJ/2 block to determine more reserve and enhance production. SENES Consultants India Pvt. Ltd. (SNES) a NABET-QCI Accredited firm has been entrusted to conduct an Environmental Impact Assessment (EIA) for the proposed activities in AA-ONJ/2 Block. The EIA study comprised of initial scoping & site visit, environmental monitoring & surveys, preparation of draft EIA-EMP report for Public Hearing (PH). Block Location & Accessibility The AA-ONJ/2 block of ONGC covers approximately 1277 sq. km area encompassing Cachar district of Assam (802 sq.km), Jiribam district of Manipur (220 sq.km) & Aizawl and Kolasib district of Mizoram (255 sq.km.). The geographic location of the AA-ONJ/2 Block is included within the Survey of India’s Topo- Sheet No. 83D/13, 83D/14, 83D/15, 83H/1, 83H/2 and 83H/3 (1:50000 scale).The block area lies between latitudes 24°17'00" & 24°48'00" and longitudes 92°47'30" & 93°10'00". Major portion of the block is traversed by two main roads, i.e. The Aizawl Road (NH-54) which connects Silchar with Mizoram state capital Aizawl, and the Imphal Road (NH-53) which connects Silchar with the Manipur state capital Imphal. Majority of the well sites can be accessed by Aizawl Road. Silchar is the main railway station which connects Silchar with Lamding. This is the nearest railway route for getting access to the block. The nearest Airport to the Block is Kumbhirgram airport of Silchar, which is approximately 26km from Silchar town. Land Lease During the site selection process, all legal requirements will be considered and surface location finalized. Once surface drilling location is finalized, land acquisition will be done. For proposed wells lying in forest land, forest clearance is being acquired from Forest Department. On the other hand, if well location falls in agricultural lands, crop compensation will be provided to the land owner. The estimated land required per drill site is approximately 2.25 ha. Project Activities Project activity involves Well site preparation, construction of access roads, Well drilling and testing. Site closure and decommissioning of wells not indicative of potential hydrocarbon reserves.
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Site Preparation & Construction Drill site Site preparation will involve leveling, filling and consolidation of the site for staging equipment and machinery. Site along with campsite will be duly fenced to a height of about 4 ft using chain link and barbed wires. Clearance of vegetation is the preliminary activity that will be undertaken during drill site construction. Following this, the construction of drill site will involve top soil scraping and storage for future use, 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 with oil trap. Drilling & Testing The drilling of the wells is expected to be up to a depth of 3000 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. Drilling and wash wastewater generated will also be stored at an onsite HDPE lined pit. The water will be adequately treated in a mobile ETP to ensure conformance to the S No. 72 A (ii) Schedule I Standards for Emission or Discharge of Environmental Pollutants from Oil Drilling and Gas Extraction Industry of CPCB. 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 for each drill sites will be met through the DG sets. Two (2) Nos. of DG set of 750 KW capacities will be used during site construction. Two DG sets of 750 KW will be simultaneously operable and one will be kept as standby during drilling operation. It is estimated that 6 KLD of diesel will be required during drilling phase alone. Reserve Fuel will be stored as per Petroleum Rules 2002. Water Water demand during peak construction period is estimated to be 5 KLD for construction at each well site. During the drilling operation, water requirement at site to meet the industrial need is 20 KLD. Total water requirement at each well site during drilling activities is estimated to be 900KL, considering a total of 45 days of drilling operation (including testing & contingency period). The water requirement at the drilling sites during construction and drilling phase will be met through procurement of surface water from approved local sources/suppliers and partly through re-cycling of treated water from ETP.
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Manpower During peak construction phase (including site preparation), approximately 45-50 personnel will be engaged including skilled and unskilled labour at each well site. Both locals and labourers from outside will be engaged depending on skills and project requirements. 25-30 personnel will be employed at the drill site at each shift. Provisions for drinking water and water for other purposes, sewage disposal will be provided at drill site and campsite. Baseline Environmental Status The study of the baseline environmental status helps in assessing the existing environmental conditions and identifying the critical environmental attributes. The study of the physical, biological and socio-economic environment of the Block and an area within a radius of 10 km from nine (9) exploratory wells (study area) comprises of the baseline environment. 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 during the pre-monsoon reveals that the pre-dominant wind direction is from West South West with an average speed of 1.28 m/s. Air Quality
The ambient air quality representing PM10, Sulfur Dioxide (SO2), Nitrogen Dioxide (NO2) was monitored at eight different locations for 24 hours twice a week during May-June,
2013.Volatile Organic Carbons (VOCs), Methane (CH4), non-methane hydrocarbons (NMHCs) were monitored for the same period. All the parameters were found to be below the National Ambient Air Quality Standards (NAAQS), 2009. The average 24 hourly PM10 at the monitoring locations ranged between 44-63µg /m3 (NAAQS-100 µg/m3). The average 24 3 3 hourly NO2 at the monitoring locations ranged between 19.2-24.8 µg/m (NAAQS-80 µg/m ).
The average 24 hourly SO2 at the monitoring locations were found to be in the range of 4.8- 6.6µg/m3 (NAAQS-80 µg/m3). Average value for methane hydrocarbon ranged between 1.0- 1.21 PPM whereas non methane hydrocarbon and VOC concentration at all sampling location was found to be <0.5 PPM and <2.8 µg/m3 respectively. Noise Quality The noise quality was monitored for 24 hours at eight locations close to the drill sites. The ambient noise quality at day and night was in compliance to the Noise Limits set for the residential area as per Noise Pollution (Control and Regulations), 2000. The daytime noise level was found in the range between 48.5-52.8 dBA whereas the night time noise level was found in the range between 38.6-40.1 dBA.
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Physiography The present day basin reflects three distinct tectonic phases. The earliest was late cretaceous to Eocene block faulting and development of a northern easterly dipping shelf. During the second phase, in Oligocene time, uplift and erosion occurred north of the Dukai fault, many basement faults were reactivated and many basement controlled structures became prominent (Naidu and Panda, 1997). Late Miocene through Pliocene, extensive alluvial deposition followed Oligocene uplift and erosion. Geology Geological mapping of the block identified three exposed structures namely - Ramphan Anticline, Bhuban Anticline and Teidukkan Anticline. In Manipur province of the block, structures like Tenghil Anticline is predominant. Hydrogeology The entire area of Cachar district is represented by unconsolidated, semi-consolidated and consolidated formations. The semi-consolidated Tipam sandstones form good repository in the area. The depth to water level varies from a few meters to 4m bgl in alluvial sediments particularly in north and south of Silchar and in western parts while it varies from a few metres to 2m bgl in the central parts. On the other hand, the aquifer thickness ranges from 10- 20m bgl in Imphal East district. Ground water is found to occur at a depth of 22.35m bgl during pre-monsoon period and it is upto 11.92m bgl during post monsoon period.
Groundwater Quality Groundwater was collected and analyzed as per IS: 10500 from four locations in the study area. All the parameters analyzed was under the acceptable and permissible limit of IS: 10500 except turbidity and iron that was found to be exceeding the permissible limit as per IS: 10500:2012 in all the samples. Heavy metals were found to be below detection limit. Fecal Coliform is present in one sample. Watershed and Drainage The study area is included under the catchment of Barak River. The channels traversing through the field in included under the sub-water sheds of Barak River viz. Sonai River, Rukni River, Jiri River and Chiri River. Apart from this, some local water channels i.e. Lating Khal, Mach Khal and Naga Khal are flowing thorough the block. Surface Water Quality Surface water was sampled from four (4) representative locations. The water samples were analyzed and compared with the Designated Best Use Classification of Surface Waters as per CPCB. The pH of the surface water samples varied from 6.7-7.1. The DO levels at all the locations exhibited values ranging from 3.6-7.8 mg/l. BOD values in all the surface water samples were detected at concentration between <2.0-9.88mg/l-3.00 mg/l whereas COD value ranges between 7.72-30.89mg/l. Electrical conductivity values of the samples ranged
SENES/K-20200/December 2013 iv ONGC EIA Studies for Exploratory drilling at Pre-NELP Block AA-ONJ/2 between 53.7-76.6 microsiemens/cm, sodium absorption ratio varied between 0.21-0.34. Free ammonia contents of all the samples were found to be less than 0.1 mg/l. Chloride and nitrate content of all collected surface water sample ranges from 1.97-3.94mg/l and 0.9-1.73 mg/l respectively. The total coliform count of the surface water samples varied between (02MPN/100ml) at Upstream of Barak River to 900 MPN/100ml at Rukni River. Though the water quality is not coming under any class designated by CPCB Water Use Criteria, but during the field visit it has been observed that the water is being used for irrigation, bathing, cleaning and for catching fishes. Land Use The land use of the study area shows that majority of the land (76.5%) in the area is forest land. 12.36% land is used for agricultural purposes. 9.14% of land is occupied by settlements whereas tea garden constitutes only 0.04% of the total land. River, Riverbeds and water bodies constitutes 2.09% of total land. Roads including NH-53, NH-54 along with the other access roads i.e. Sonai Road, NEEPCO-Tuirial Road constitutes 0.11% of the total land.
Soil Quality The major soil types found in the Cachar district are Non-Laterized Red Soil, Old Riverine Alluvium, Lateritic Red Soil and Peat Soil. On the other hand, two major types of soil are found in Imphal East district namely residual and organic soil. Kolasib and Aizawl district is characterized by its acidic nature and is deficient in base material. The primary analyses of the soil sampled from agricultural field at 5 locations in the study area shows that the soils are clayey and acidic in nature and are high in available nitrogen content. 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 AA- ONJ/2 Block is flood prone, but majority of the proposed exploratory 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 regarding sensitive ecological habitat and sensitive flora and fauna in the study area revealed that the block falls in Lower Jiri Reserve Forest, Barak Reserve Forest and Innerline Reserve Forest. The region falls within Indo Burma Hotspot as delineated by International Union for Conservation of Nature and Natural Resources (IUCN) and has been accorded international status in terms of conservation of biodiversity. It has the richest reservoir of plant diversity in India and is one of the ‘biodiversity hotspot’ of the world supporting about 50% of India’s biodiversity.
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Socioeconomic Environment Cachar district of Assam comprises of 2 administrative sub divisions which is further subdivided into 5 revenue circles. The total population of the district as per 2011 provisional census data is 1,736,319 with a decadal growth rate of 20.17%. The sex ratio is 959and the population density is 458 per sq.km. Total population of Imphal East district as per 2011 provisional census figure is 4, 52,661 with a decadal growth rate of 14.63%. The sex ratio is 1011 and the population density is 638 per sq. km. On the other hand, Kolasib and Aizawl district has a population of 83,054 and 4,04,054(as per 2011 provisional figure). Decadal growth of these two district 27.28% and 24.07% respectively. The sex ratio of Kolasib and Aizawl district is 956 and 1009 whereas the population density is 61 person/sq.km and 208 person/sq. mile.
Socioeconomic profile Forty Two villages within the study area were selected for developing the socioeconomic profile of the area. It was seen from the Census Data of 2001, Binnakandi Grant has the highest population (4898 persons). The highest literacy rate (95.99%) was observed in Fulertol and the least was found in Machkhal Pt III village (30.86%). The total working population varies from 23.36% (Kaptanpur Pt XVII Village) to 92.93% (Kani Village). Approximately 38% of the population depends on agriculture.
Socioeconomic Infrastructure Of the study area villages 6 villages are having medical facilities within the village which includes one allopathic hospital, one allopathic dispensary, one health centre and one primary health centre. In terms of educational facilities, 79 primary schools, 29 middle schools, 6 high schools and 2 higher secondary schools are present within the study area villages. Drinking water facility is present in all of the assessed villages. Drinking water facility in terms of either tube well or hand pump is present in all study area villages.
Environmental 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 may affect the ambient air quality temporarily. Air pollutants like NOx will also be generated as a result of flaring of natural gas.
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Impact on Noise Quality 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. 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 Of the nine (9) exploratory drilling locations, one well in Assam province of the block comes under Barak Reserve Forest whereas two (2) wells located in Mizoram province located in Inner Line Reserve Forest. Reviewing of ecological conditions of the exploratory block 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 during the decommissioning procedure. The area is free from any migratory route or corridors (daily and seasonal movement) for animals. However, noise generated from drilling activities, lighting at well site, traffic movement will cause of disturbance to local fauna. Impact on Socio economic Environment The proposed well sites are located both on Private Land and Forest Land. Necessary Clearance will be taken from Forest department before using this land for exploratory drilling purpose. ONGC will take this land through private land through negotiation. Necessary payments will be made against purchase and crop compensation to concerned land owners. The proposed project would not require any displacement of villagers.
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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 therefore 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 drilling activities in AA-ONJ/2 Block. 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 6.75X10-2. Thus the Blow out frequency for the proposed project is calculated at 1.65 X 10-1 per well drilled.
Even on blowout, the probability of ignition is approximately ~0.0067% i.e. negligible. The consequence analysis of Blowout assessed by using ALOHA shows settlements like Latingkhal, Bhitor Narayanpur and Hmarkhawlien might be affected due to pool fire and Natural gas release.
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 ONGC for the proposed project. The key mitigation measures specific for each management plan have been discussed in the Table below:
Environment Sl. Management Key Mitigation Measures No 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 Sl No 95 GSR 371(E) dated 17.5.2002. 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 S No. 72 B. for Discharge of Gaseous Emissions for Oil & Gas Extraction Industry. 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 Sl No 94 GSR 371(E) dated 17.5.2002. Effective noise barrier at the fence-line of the sites. Install and maintain effective run-off controls, including silt traps,
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Environment Sl. Management Key Mitigation Measures No Plan straw barriers etc so as to minimize erosion. Fuel and chemical storage areas will be paved and properly bunded. 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 or else eco-friendly synthetic based mud in necessary conditions
2 Waste Use of low toxicity chemicals for the preparation of drilling fluid. Management Plan Management of drill cuttings, waste drilling mud, waste oil and domestic waste will be made in accordance with S No. 72 C.1.a Schedule I Standards for Emission or Discharge of Environmental Pollutants from Oil Drilling and Gas Extraction Industry of CPCB as modified in 2005Necessary 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 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, 2008 to be maintained during storage 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
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 including highways during vehicular movement.
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Environment Sl. Management Key Mitigation Measures No Plan 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 Traffic 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 order, will be regularly inspected and properly maintained as per IS Management Plan 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. Prior to the commencement of the proposed activity, a consultation
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Environment Sl. Management Key Mitigation Measures No Plan concerns program will be conducted by ONGC 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. ONGC 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 Environment Sl. Management Key Mitigation Measures No 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 Sl No. 72 B CPCB Guidelines for discharge of gaseous emissions for Oil Drilling and Gas Extraction Industry. 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. Proper casing and cementing of drilling well will be done to prevent
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Environment Sl. Management Key Mitigation Measures No Plan 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 will be achieved either through solar evaporation or 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 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 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 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.
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Environment Sl. Management Key Mitigation Measures No Plan 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 ONGC 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
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Environment Sl. Management Key Mitigation Measures No Plan the proposed project associated impacts and their mitigation. ONGC 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 ONGC.
Project Cost An estimated INR 270 Crore will be expended for the drilling of nine exploratory wells. The budget for implementation of the EMP is 60.13 Lakhs.
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1 Introduction
1.1 BACKGROUND The Assam-Arakan Basin is situated in the Northeastern part of India and is categorized as ‘Category-I’ Basin. The Basin covers an area of 116000sq.km. Since its inception, extensive proliferation in exploration and development was made by ONGC in the Assam-Arakan Basin. ONGC intends to drill new exploration wells in AA-ONJ/2 Block spreading across Cachar District (Assam), Imphal East district (Manipur), Aizawl and Kolasib district (Mizoram). The exploratory drilling proposed in AA-ONJ/2 Block is included under activities specified in (Activity 1b) of the new EIA Notification dated 14th September 2006.It requires Environmental Clearance (EC) from the Ministry of Environment and Forests (MoEF). In addition, the EIA, also, has to be formally approved by the Directorate General of Hydrocarbons (DGH), Government of India (GoI) as Production Sharing Contract (PSC) requirements. ONGC 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- 11011/91/2012-IA II (I) dated 13th July, 2012. The approved ToR is attached as Annexure 1.1 and is in compliance to ToR is presented at Table 1.1. SENES India has been entrusted by ONGC to undertake an Environmental Impact Assessment (EIA) study for AA-ONJ/2 Block located at Cachar, Imphal East, Aizawl and Kolasib districts of Assam, Manipur and Mizoram respectively. Additionally, as a part of ONGC’s corporate Environment Policy, this EIA study will play an important role in formulating appropriate environmental management response for the proposed exploratory drilling project. In this perspective, SENES India has strived to fulfill project objectives delineated in the section below.
1.2 OBJECTIVE OF THE STUDY The objectives of the EIA study are as follows: Establishing the prevailing baseline environmental and socio-economic condition of the AA-ONJ/2 Block and its surroundings along with compliance needs for environmental approvals to carry out exploratory drilling activity; Assessing environmental and socioeconomic impacts arising out of the proposed exploratory drilling activities; Recommending appropriate preventive and mitigative measures to eliminate or minimize pollution, environmental & social disturbances during the life-cycle of the project, ensuring compliance with environmental laws and regulations as applicable ;
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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 of about 3 months duration to understand the environmental and social impacts of the project and recommend suitable preventive / mitigative actions through the Environment Management Plan (EMP). Scope for the study is finalized as per ToR has been summarized below: Conducting reconnaissance visit to assess the environmental and socio economic setting of the block; Undertaking site visits for collection of primary and secondary information on environmental and social setting in the AA-ONJ/2 Block; Formulating environmental monitoring plan and conducting monitoring of the environmental components as per the plan; Conducting public consultation; Assessing environmental and social impacts; and Formulating EMP.
1.4 STRUCTURE OF THE EIA REPORT The EIA report documents 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 adverse 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 Chapter 6: Environmental Management Plan 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.
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TABLE 1-1: COMPLIANCE TO MOEF TOR Sl. ToR Points Issued Addressed at EIA No 1 Executive Summary of the Project Provided in the beginning of the Report 2 Project Description, project objectives and Provided in Chapter 2 of the project report. Project Benefits Project objectives and Project Benefits are incorporated in 2.2.1 and 2.2.2 respectively. 3 Site details within 1km of the each proposed Site details within 1 km of each proposed well, any habitation, any other well given in Section 2.5.2 installation/activity, flora and fauna approachability to Site, other activities including agricultural/ land, satellite imagery for 10 km area 4 Details of forest land involved in the proposed Details of forest land involved is given in project. A copy of forest clearance letter, if Section 2.6.1 applicable 5 Permission from the State Forest Department ONGC has requested State Forest regarding the impact of the proposed plant on the Department to identify the current surrounding National Park/Wild life ownership of Land for 4 wells as they are Sanctuary/Reserve Forest/ Eco sensitive area, if observed to be within the Forest land as any. Approval obtained from the State/Central per the toposheet (1:250000 scale). Government under Forest (Conservation Act, Detailed in Section 2.6.1 1980 for the Forest) should be submitted 6 Distance from nearby critically/severely polluted No critically/severely polluted area is area as per Notification dated 13th January, 2010, present within 10km radius of the block. if applicable 7 Do proposal involve rehabilitation and The proposed project will not require resettlement? If yes, details thereof rehabilitation and resettlement 8 Environmental clearance for the existing site as No overlapping field is present for which issued by the Ministry. Consent to operate and environmental clearance is required. authorization accorded by the APCB along with point-wise compliance report. 9 Detailed breakup of project costs including Total Cost of drilling 9 wells is 270 Crores recurring cost. as given in Section 2.9 10 Environmental considerations in the selection of The environmental considerations are the drilling locations for which environmental given in Section 2.5.1 clearance is being sought. Presenting analysis suggested for minimizing the footprint giving details of drilling and development options considered. 11 Baseline data collection for air, water and soil for Please refer Section 3.1.2 for baseline air one season leaving out the monsoon season in an quality, Section 3.1.6 baseline ground area of 10 km radius with center of Oil field as water quality, Section 3.1.8 for baseline its center covering all proposed drilling wells. It surface water quality and Section 3.1.10 includes: for baseline soil quality respectively.
12 Topography of the project site Provided in Section 3.1.4
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Sl. ToR Points Issued Addressed at EIA No 13 Ambient air quality monitoring at 8 locations for Ambient Air Quality provided in Section PM10, SO2, NOx, VOCs, Methane and non- 3.1.2 methane HC 14 Soil sample analysis (physical and chemical Result of Soil Sample Analyses Section properties) located in 5 locations 3.1.10 15 Ground and surface water quality in the vicinity Result of Ground and Surface Water given of the proposed wells site in Section 3.1.6 and Section 3.1.8 respectively. 16 Climatology and Meteorology including wind Climatology and Meteorology included in speed, wind direction, temperature, rainfall, Section 3.1.1 relative humidity, etc. 17 Measurement of noise levels within 1 km radius Noise levels given in Section 3.1.3 of the proposed wells 18 Vegetation and Land use, Animal Resources Vegetation and landuse given in Section 3.1.9 and Section 3.2 respectively
19 Incremental GLC as a result of DG set operation Incremental GLC for NOx, PM, HC and SOx given in Section 4.2.2 20 Potential environmental impact envisaged during Please refer Chapter 4 of the Project various stages of project activities such as site Report activation, development, operation/maintenance and decommissioning 21 Actual source of water and “Permission” for the ONGC will buy water from Authorized withdrawal of water from the competent vendor (Please refer Section 2.7.2) authority. Detailed water balance, waste water generation, recycling and its final discharge 22 Noise control and measures to minimize Noise control and measures given in disturbance due to light and visual intrusions in Section 6.1.1 case of coastally located areas 23 Treatment and disposal of wastewater Treatment and disposal of wastewater given in Section 2.7.8 24 Details of generation, treatment and management Solid waste generation, treatment and of solid waste management given in Section 2.7.9 25 Management of spent oil and loose material Spent Oil and Loose Materials will be collected in metal drums kept in secured dyked area & disposed at used oil recycling facility given in Section 6.1.2 26 Storage of chemicals and diesel at site Chemicals and diesels will be stored on paved areas, Bund wall will be provided to diesel storage area, Spill kits will be made available in chemical and diesel storage area, covered shed will be constructed for storage areas. Details given in Section 2.6.2 and Section 2.7.3 27 Commitment for the use of WBM only WBM will only be used. Where required eco-friendly synthetic mud will also be used as given in Section 2.7.8
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Sl. ToR Points Issued Addressed at EIA No 28 Mud make up and mud and cutting disposal The mud will be made up partly with options considered should be listed with selective recycled water from Rig wash and fresh option water and mud cutting will be temporarily stored at HDPE lined pits at the site. Later it will be disposed according to its hazardous and non-hazardous nature. Details provided in Section 2.7.9 29 Hazardous material usage, storage accounting Hazardous material usage, accounting and and disposal disposal provided in Section 2.7.9 30 Disposal of packaging waste from site Packaging waste will be given to local waste sellers as provided in Section 2.7.9 31 Oil spill emergency plans in respect of Oil spill emergency plans in respect of recovery/reclamation recovery/reclamation given in Section 6.1.2
32 H2S emission control Earlier exploration shows the absence of H2S in these Blocks as given in Section 2.9.2. Though a H2S contingency plan exists for ONGC that will come into action on detecting H2S at any stage of drilling. 33 Produced oil handling and storage Stored temporarily in Oil Pits and later transferred through tankers to the nearest GGS as given in Section 2.6.2 34 Details of scheme for oil collection system along Not Applicable with process flow diagram and its capacity 35 Details of control of air, water and noise Not applicable pollution in oil collection system 36 Disposal of produced/formation water Produced water will not be produced here. Formation water will be solar dried an injected into injection wells as given in Section 6.1.2 37 Whether any burn pits being utilized for well test Burn Pits will not be used. operations or not 38 Restoration and decommissioning plans which Site Closure Plan given in Section 6.1.4 should include mud pits and wastage restoration and documentation and monitoring of site recovery 39 Measures to protect ground water and shallow Measures to protect groundwater and aquifers from contamination along with its shallow aquifers given in Section 6.1.1 monitoring plan 40 Risk assessment and disaster management plan Risk Assessment and Disaster for independent reviews of well designed Management Plan is incorporated in construction, etc for prevention of blow out Chapter 6 41 Environmental Management Plan and Environmental Management Plan is Environmental Audit to be conducted incorporated in Chapter 6 As per corporate environmental policy of ONGC, the organization conducts periodic
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Sl. ToR Points Issued Addressed at EIA No environmental audit. will be provided by SENES 42 Documentary proof of membership of common Common TSDF is not present; therefore disposal facilities, if any this point is not pertinent in this case. 43 Details of environmental and safety related Regular health check up of ONGC documentation within the company including personnel conducted as per ONGC HSE documentation and proposed occupational health Policy. Surveillance safety programs and safety and surveillance safety programme for carried at regular intervals and all personnel on site. This should include documented. Refer Section 6.1.7 monitoring programme for all personnel at site. This should also include monitoring programme for the environment. 44 Total capital and recurring costs for 60.13 lakh will be utilized for environmental control measures environmental control measures. Provided in Table 6.2 45 A copy of Corporate Environment Policy of the Provided in Box 6.1 of Chapter 6 ONGC as per the Ministry’s O.M No.-J- 11013/41/2006-IAII(I) dated 26th April, 2011 available on the Ministry’s website 46 Any litigation pending against the Project and or Not Applicable any direction/order passed by any court of law against the Project. If so, details thereof. 47 A tabular chart with index for point-wise Provided in Table 1.1 in Section 1.1 compliance of above TORs
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2 Description of the Project
2.1 OVERVIEW Oil and Natural Gas Corporation (ONGC) is the leader in Exploration and Production (E&P) activities in India having 72% contribution to India’s total production of crude oil and 48% of natural gas. ONGC has established more than 7 billion tones of inplace hydrocarbon reserves in the country. In fact, six out of seven producing basins in India have been discovered by ONGC. The Pre-NELP Block AA-ONJ/2 was awarded to ONGC(100%PI) along with the operatorship by the Government of India (GoI) vide letter no. 0-19025/1712009-ONG-D-V dated 15.03.2011. The Block covers an area of 1277sq.km covering three states of Assam (802sq.km), Mizoram (255sq.km) and Manipur (220sq.km). The block area lies between latitudes 24°17'00" & 24°48'00" North and longitudes 92°47'30" & 93°10'00" East. During the current program, ONGC is planning to drill 9 exploratory wells in AA-ONJ/2 block to determine more reserve and enhance production.
2.2 OBJECTIVES AND BENEFITS OF PROPOSED EXPLORATORY DRILLING ACTIVITIES After the analysis of geological formation of the Oil Field, ONGC now plans for exploratory drilling of 9 wells to determine the prospect of potential hydrocarbon sources.
2.2.1 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.
2.2.2 Project Benefits The Project will ultimately cater to fulfill the energy requirement of India. Additionally, the Project will benefit people living in neighboring villages in relation to direct & indirect employment associated with various project activities and will boost the local economy. The proposed project will also result in the improvement of existing infrastructure for enabling the transportation of drilling rig and ancillary equipment.
2.3 AA-ONJ/2 FIELD LOCATION & DESCRIPTION
2.3.1 Location The AA-ONJ/2 block of ONGC covers approximately 1277 sq. km area encompassing Cachar district of Assam (802 sq.km), Jiribam district of Manipur (220 sq.km) & Aizawl and Kolasib district of Mizoram (255 sq.km.). Regional setting of the Block is shown in Figure
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D EIA Studies for Exploratory drilling at Pre-NELP Block AA-ONJ/2
2.1. The geographic location of the AA-ONJ/2 block is included within the Survey of India’s Topo- Sheet No. 83D/13, 83D/14, 83D/15, 83H/1, 83H/2 and 83H/3 (1:50000 scale).The block area lies between latitudes 24°17'00" & 24°48'00" and longitudes 92°47'30" & 93°10'00". The Block location map superimposed on satellite imagery is shown in Figure 2.2. Coordinates of the block boundary are shown in Table 2-1
TABLE 2-1: GEO-COORDINATE OF BLOCK BOUNDARY Point Latitude Longitude A 24°48'00" (N) 93°10'00" (E) B 24°47'45" (N) 92°50'45" (E) C 24°42'45" (N) 92°50'00" (E) D 24°42'30" (N) 92°58'30" (E) E 24°32'30" (N) 92°58'15" (E) F 24°32'45" (N) 92°48'30" (E) G 24°26'27" (N) 92°49'27" (E) H 24°18'45" (N) 92°47'30" (E) I 24°17'00" (N) 93°02'30" (E) J 24°43'20" (N) 93°08'10" (E)
2.3.2 Accessibility
Roads Major portion of the block is traversed by two main roads, i.e. The Aizawl Road (NH-54) which connects Silchar with Mizoram state capital Aizawl, and the Imphal Road (NH-53) which connects Silchar with the Manipur state capital Imphal. Majority of the well sites can be accessed by Aizawl Road. Few metalled roads and interval village roads (under PMGSY Scheme) emerging from Aizawl and Imphal roads could be used to reach the well sites. However, exploratory well RTNG-1 is yet to be assessed by ONGC, one of the reasons being inaccessibility to access road.
Railway Broad gage railway line is not present to connect the block with adjoining cities. Silchar is the main railway station which connects Silchar with Lamding. This is the nearest railway route for getting access to the block.
Airport The nearest Airport to the Block is Kumbhirgram airport of Silchar, which is approximately 26km from Silchar town. The accessibility map is shown in Figure 2.3.
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FIGURE 2-1: REGIONAL SETTING MAP OF AA-ONJ/2 BLOCK
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FIGURE 2-2: AA-ONJ/2 BLOCK LOCATION MAP ON TOPOSHEET
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FIGURE 2-3: AA-ONJ/2 BLOCK ACCESSIBILITY MAP
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2.4 AA-ONJ/2 BLOCK
2.4.1 Environmental Settings of the Block The AA-ONJ/2 Block encompasses the Cachar district of Assam, Aizawl and Kolasib district of Mizoram and Imphal East (Jiribam) district of Manipur. Total stretch of the Block is 1277 sq. km of which 802 sq km falls in Assam, 255 sq.km falls in Mizoram and 220 sq km falls in Manipur. The key physical features (Refer Figure 2.5) of AA-ONJ/2 Block have been described below: The Block is polygonal in shape. The western boundary of the Block is more or less aligned with the NH 54, i.e. Mizoram Road connects the Silchar city with the Kolasib and Aizawl. On the other hand, NH-53 i.e. Manipur road which runs through the Northern side of the block connects Silchar city with exploratory drill sites located in Manipur province of the Block. Some of the well site can utilize existing PWD road to reach upto the drill site from the access road whereas for sites located in forest land, new approach roads need to be constructed or existing roads strengthened for getting access to the drill site. Niz Rupai Bali, Munsirgram, Tulagram Part-II, Bidyaratanpur, Telka TE village, Dalugram, Kaptanpur, Pabda Basti, Hmarkhawlien, Latingkhal, Biboni, Chandranathpur, Saiphai Basti, Saiphum Basti are the notable settlement present in and around the proposed drill sites. The entire block is located in the catchment of Barak river. Sonai, Jiri and Chiri river are tributaries of Barak flowing through the Block from Southern to Northern direction. Rukni is another tributary of Sonai river which also flows through the Block. Two (2) drill sites located in Kolasib and Aizawl districts of Mizoram in Southern direction of the Block and two (2) sites in Assam are located in forest area. No ecologically sensitive areas are located within the Block. The majority of the wells in Assam and Manipur are located in rural areas have agricultural land in its surroundings. Silchar is the major town from which the block can be accessed easily. Only a tea garden i.e. Telka Tea Garden is present inside the Block boundary. Apart from ONGC facilities that will be coming up during exploratory drilling, no other industrial set up is present within the Block.
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Photo 2-1: Nagakhal flowing adjacent to the Photo 2-2: Rupai Bali Anua (RBK-2) Proposed Drill Site (RTDN-1)
Photo 2-3: Jiri River near Latingkhal Village, Photo 2-4: Land use type adjoining the drill site, Manipur (RJDR) Assam (RTDN-1)
Photo 2-5: Access Road to Exploratory Drill Photo 2-6: Settlement at Telka Tea Estate Site, Manipur (RJDR) Village, Assam (RBK-3)
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FIGURE 2-4: ENVIRONMENTAL SETTINGS OF AA-ONJ/2 BLOCK
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2.4.2 Existing Activity in Oil Field Only drill sites are identified by ONGC for this block and no pre construction activities such as construction of access road has been started as yet.
2.4.3 Environmental Compliance The proposed block i.e. AA-ONJ/2 is virgin and no activity is currently happening in this particular block for which environmental clearance or Consent to Establish or Consent to Operate or any application to meet the Environmental compliance is required.
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 was taken to locate wells distantly from these receptors. Primarily, agricultural land and land adjoining a hillock were selected for current well drilling programme. 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 of 9 exploratory drilling wells are proposed in the AA-ONJ/2 block during the planned period. Tentative well coordinates are provided in Table 2.2 and the locations of the wells at AA-ONJ/2 Block are shown on satellite imagery in Figure 2.5.
TABLE 2-2: CO-ORDINATES OF TENTATIVE WELL LOCATIONS Location Latitude Longitude District State RBK-1 24°44'13.06" (N) 92°52'13.49"(E) Cachar Assam RBK-2 24°46'23.00" (N) 92°55'42.56"(E) Cachar Assam RPAA 24°47'20.05"(N) 93°02'16.31"(E) Cachar Assam RBK-3 24°42'47.86"(N) 93°00'50.46"(N) Cachar Assam RLBK-1 24°45'21.39" (N) 93°00'25.72"(E) Cachar Assam RTDN-1 24°30'24.10"(N) 92°52'11.35"(E) Cachar Assam RJDR 24°43'20.05"(N) 93°06'14.51"(E) Imphal East Manipur RTNG-1 24°22'57.04" (N) 92°59'50.14(N) Aizawl Mizoram RTDN-2 24°22'08.14"(E) 92°51'23.44"(N) Kolasib Mizoram
2.5.2 Salient Features of the Wells The water consumption, generation of drill cuttings and drilling fluid is determined by depth and type of well as presented in Table 2.3.
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TABLE 2-3: SALIENT FEATURES OF A TYPICAL EXPLORATORY WELL
Type of Well Depth of Well Water Drill Cutting Drilling Fluid Consumption Exploratory 3000 m 900-1000m3 Above 225m3 1500m3
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FIGURE 2-5: LOCATION OF PROPOSED WELLS ON SATELLITE IMAGERY
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2.5.3 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 satellite imagery. Well-wise environmental settings are described below. RBK-1 The proposed well site is located at the agricultural land of Dhanipur village in Cachar district. The site is adjacent to Sonai road and is pucca in nature. The site could be alternatively accessed by Dhanipur Road which is of 5m width and pucca in nature. A 50m approach road needs to be constructed for getting access to the actual drill site. Settlement of Tundarkanti and Dhanipur village is observed at the NE and SW side of the site respectively. Sonai River is flowing from the NE side at an approximate distance of 900 m. Majhir gram Pakka Masjid is present on the Eastern side at 500m distance. Electrical installation is observed adjacent to proposed drill site. The land use map of RBK -1 is presented on Figure 2.6
Photo 2-7: Proposed Exploratory Drill Site Photo 2-8: Approach Road to Drill site (RBK-1) (RBK-1)
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FIGURE 2-6: LAND USE OF RBK-1
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RBK-2 The proposed well site is located in the agricultural land of Kaptanpur PT. Settlements are present adjoining the drill site. Sonai road acts as an approach road to this drill site and passes through the Southern side of the study area. Munsirgram Road is traversing through the study area and acts as an approach road to this drill site. The width of this road is not sufficient for movement of drilling rig. 200m road need to be prepared to reach to the drill site from Munsirgram Road. Settlement of Niz Rupai Bali is present in the NW side at a distance of 200m, whereas settlement of Munsirgram is present at 1.1 km distance on the NE side. Rupai Bali Anua is situated at 300m distance on Northern side of the proposed site. The land use map of RBK-2 is presented in Figure 2.7
Photo 2-9: Proposed Exploratory Drill Site Photo 2-10: Settlement near Drill Site (RBK-2) (RBK-2)
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FIGURE 2-7: LAND USE MAP OF RBK-2
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RPAA The well site is located at the forest land near Hmarkhawlien in Cachar district. The proposed drill site is surrounded by hillocks. The nearest access road is till Hmarkhawlien which lies on NH-53. No approach road is present to reach the drill site from Hmarkhawlien.It is to be constructed for a stretch of 500m to reach the drill site. Imphal Road traverses along the West to Northern side of the study area. Settlement of Hmarkhawlien is present at 100m distance on the NW side of the proposed site, whereas settlement of Digor Phulertol Part III is located on the Northern side at 1 km distance. Settlement of Phulertol is present at approximately 1km distance. Barak river is flowing at an approximate distance of 700m on SW side of the proposed site. A.G.English ME School is situated on the Northern side of the site at 100m distance. The land use map of RPAA is presented in Figure 2.8
Photo 2-11: Proposed Exploratory Drill Site Photo 2-12: Public utilities present near Drill located on Forest Land (RPAA) Site (RPAA)
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FIGURE 2-8: LAND USE MAP OF RPAA
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RBK-3 This proposed well is located in the forest land in Cachar district. Sonai Ghat road can be used as an access road for this proposed drill site located at an approximate distance of 4.0 km on the Western side. Tilka Bagan road is the approach road to the drill site which diverges off as Kashipunji Road leading to the drill site. The nearest settlement to this well is at Robipur Punji which is located at an approximate distance of 2.1 km on North Eastern side. Machkhal is on the Northern side of the proposed site at 1.2km distance. It is to be mentioned that, a 2.8 km road,. Kashipunji Road, needs to be strengthened to reach to the drill site. The land use map of RBK-3 is presented in Figure 2.9
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FIGURE 2-9: LAND USE MAP OF RBK-3
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RLBK-1 The proposed well is located in the agricultural land near Pabda Basti. The site can be accessed through Binnakandi Silchar road which is pucca in nature. The PWD road i.e. Telka road is the approach road which connects the site with Binnakandi-Silchar road was observed having sufficient width but kutcha in nature. 20m road need to be constructed from Telka road for gaining access to the drill site. The nearest settlement to this proposed well is at Pabda Basti, approximately at a distance of 100m on the NW side. Marshy lands are present on the Southern and SE side of the proposed site. The land use map of RBK-3 is presented in Figure 2.10
Photo 2-13: Proposed Exploratory Drill Site Photo 2-14: Approach Road to Drill Site (RLBK-1) (RLBK-1)
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FIGURE 2-10: LAND USE MAP OF RLBK-1
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RTDN-1 The drill site is located within agricultural lands of Bhitor Narayanpur village. The approach road to this drill site is Mizoram Road. The distance of the exploratory drill site is approximately 2 km from Rajnagar which lies at a distance of 4km from Bhaga and is to be approached through Kutcha Road. Strengthening of this approach road is required to reach to the drill site. A water bearing channel namely Udkhal passes through the approach road to drill site. A local water channel, Nagakhal is flowing at a distance of 500m on the NW direction of the proposed site .Bidyaratanpur is the notable settlement present at the NE side of the proposed drill site at 2km distance. Settlement of Jamalpur Forest village is present on the Southern side of the proposed site at an approximate distance of 600m whereas settlement of Bhitor Narayanpur is at approximate distance of 250m from the proposed drill site. The land use map of RTDN-1 is presented in Figure 2.11
Photo 2-15: Proposed Exploratory Drill Site Photo 2-16: Approach Road to Drill Site (RTDN-1) (RTDN-1)
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FIGURE 2-11: LAND USE MAP OF RTDN-1
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RJDR The site can be accessed by Jiri-Tipaimukh (JT) road. Distance of the proposed site from the approach road i.e. the entry point to Latingkhal village is approximately 3km and kutcha in nature. The approach road is of sufficient width but require strengthening for movement of drilling rigs. A new approach road of 180m stretch is needed to be constructed to reach to the actual drill site. The proposed well site is located on agricultural lands adjacent to Latingkhal village of Manipur district. Latingkhal nullah is flowing through the Eastern and Southern side of the proposed site and ultimately merges with Jiri River. Jiri river is about 0.5 km NW of the proposed well site. Settlements are present on the Eastern and Southern side of the proposed site at an approximate distance of 200m. Latingkhal market is situated at 700m distance on North-Western side of the site. A Shiva temple is present at 600m distance on Northwestern side of the proposed site. The approach road is kutcha in nature and approximately at 3 km distance from the proposed site. The land use map of RJDR is presented in Figure 2.12
Photo 2-17: Proposed Exploratory Drill Site Photo 2-18: Approach Road to Drill Site (RJDR) (RJDR)
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FIGURE 2-12: LAND USE MAP OF RJDR
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RTNG-1 The proposed well is located in forest land of Aizawl district in Mizoram. There is hardly any approach road to the proposed site. The nearest settlement is Zokhawthiang village which is located on the NE side at an approximate distance of 1 km. Barak River is flowing through the Eastern side of the proposed well location at approximately 2 km distance. The road upto Zokhawthiang is hilly road and is of sufficient width. Approximately, a 900 m approach road needs to be constructed to reach upto the drill site. The land use map of RTNG-1 is presented in Figure 2.13
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FIGURE 2-13: LAND USE MAP OF RTNG-1
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RTDN-2 The proposed well site is adjacent to the NEEPCO-Tuirial Road of Kolasib district and is located on a forest land. The access road i.e. Sher Khan-Bhaga road is of sufficient width and is kutcha in nature. The entire stretch of road from Saiphai Basti to the drill site is required to be strengthened to reach the drill site. Additionally, 60m approach road needs to be constructed to reach to the actual drill site from NEEPCO-Tuirial road. Tuirial Hydroelectric Plant is located on SE side of the proposed drill site at 3.2 km distance. Sonai River is flowing through the Eastern direction at approximately 2 km distance. The nearest settlement of this identified drill site is Saipum Basti located on the SW at 1.5 km distance. Multicrop Jhum cultivation including beetle nut is the major livelihood of people located in and around the drill site. The land use map of RTDN-2 is presented in Figure 2.14
Photo 2-19: Proposed Exploratory Drill Site Photo 2-20: Access Road to Drill Site (RTDN-2) (RTDN-2)
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FIGURE 2-14: LAND USE MAP OF RTDN-2
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2.6 PROJECT ACTIVITIES AND SCHEDULE The lifecycle of project activities for the exploration project has been divided into distinct steps and each is described in detail in subsequent sections. Construction and decommissioning activities, apart from actual drilling for every well will take approximately three to four months. The project lifecycle has been classified into three phases:
Pre-drilling activity Site selection Land acquisition Site preparation, access and drill site construction Mobilization and rigging up Initial well construction
Drilling activity Drilling of wells Well testing
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
The major consideration for the site selection is geological formation. All locations were selected by ONGC’s drilling department based on geological data available. A preliminary site survey was already undertaken by the ONGC drilling team. Suitable drilling locations were selected based on the physical (terrain and access) and technical suitability. Based on that the following considerations were made from environmental point of view during selection of drill site: 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
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Detailed drill site and access road survey will be carried prior to taking the land on a lease basis and construction of drill site. The type of land selected for the proposed drill site along with the status of approach road to the drill site is presented on Table 2.4:
TABLE 2-4: LOCATION OF EXPLORATORY DRILL SITE WITH RESPECT TO TYPE OF LAND Type of Land on Which the Proposed Name of Well Drill Site will be Located Current Status of Land Procurement Forest land Agricultural land Land leasing process will be initiated RBK-1 √ after getting the Environmental Clearance. Land leasing process will be initiated RBK-2 √ after getting the Environmental Clearance. Land leasing process will be initiated RPAA √ after getting the Environmental Clearance. Land leasing process will be initiated RBK-3 √ after getting the Environmental Clearance. Land leasing process will be initiated RLBK-1 √ after getting the Environmental Clearance. Land leasing process will be initiated RTDN-1 √ after getting the Environmental Clearance. Land leasing process will be initiated RJDR √ after getting the Environmental Clearance. Land leasing process will be initiated RTNG-1 √ after getting the Environmental Clearance. Land leasing process will be initiated RTDN-2 √ after getting the Environmental Clearance.
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Land Acquisition During the site selection process, all legal requirements will be considered and surface location finalized. Once surface drilling location is finalized, land acquisition will be done. On one hand if the proposed well comes under forest land, forest clearance will be acquired from Forest Department .On the other hand, if well location falls in agricultural lands, crop compensation will be provided to the land owner. The estimated land required per drill site is approximately 2.25 ha. Private Land Generally, ONGC takes land on lease from villagers for 4-5 months. Additionally, if private land is required to construct approach road for moving drilling equipment, it will also be taken on lease. Forest Land In case of forest land (RTNG-1 and RTDN-2 in Mizoram province and RBK-3 in Assam province of the Block), as per Forest (Conservation) Act 1980, will take Forest Clearance (FC) from MoEF prior to any drilling activity for that particular drill site. It is to be mentioned that, ONGC has initiated the process for getting Forest Clearance. The letter of communication to Divisional Forest Office towards getting the Forest Clearance is attached in Annexure 2.1 Rehabilitation and Resettlement All proposed drill sites are away from human habitation. Therefore, any displacement will not be required for the Project. As displacement is not required, resettlement and rehabilitation is not applicable for the Project. Additionally, it is to be mentioned that, no rehabilitation or resettlement is required during construction or strengthening or widening of approach road to reach to the drill site.
Site Preparation and Access Site Preparation Site preparation will involve all activities required to facilitate the transport and operation of the drilling rig and associated equipments and machinery. Site preparation activities would involve levelling, filling and consolidation of the site for staging equipment and machinery. Site along with campsite will be duly fenced to a height of about 4ft using chain link and barbed wires. Drilling waste in the form of spent drilling mud and cuttings will be disposed on-site in a specially designed impermeable waste pit lined with HDPE lining of 1-1.5mm thickness. Drill Site Construction Clearance of vegetation is the primary activity that will be undertaken during drill site construction. After clearance of vegetation, top soil will be removed from the drill site and
SENES/K-20200/December 2013 38 ONGC EIA Studies for Exploratory drilling at Pre-NELP Block AA-ONJ/2 will be stored in top soil storage area for future use. Following this, leveling and compaction of drill site will be done by graders and mechanical rollers. After leveling and compaction, fill material will be used to elevate the drill site in such a manner that it will be 0.5m higher than the High Flood Level (HFL). Fill material will be met by excavated material for pit required for drill site and balance amount will be sourced from authorized quarry area. A garland drain will be prepared to remove the storm water from the drill site. Site preparation will also involve the following: Construction of cellar pit 3m× 3m× 3m for installation of well head and BOP. Construction of HDPE lined pit of 30'×33'×5' dimension at well site for temporary storage and disposal of drill cutting and waste mud. Construction of HDPE lined pit of 30'×33'×5', 38'×33'×5' and 23'×20'×5' dimension for temporary storage and disposal of drilling wash water. Construction of an oil pit of dimension 3'×3'×4' to contain the oil which may generate during the time of well testing. Construction of septic tanks and soak pits to dispose the domestic wastewater at the drill site.
The transport of rig including ancillary equipments and camp facilities including truckload requirement during sourcing of fill material to the site is expected to comprise around 60 trailer loads. Though the rig and related equipments will be directly brought to site, spares, chemicals and other materials will be received from ONGC base at Silchar. Materials will be intermittently supplied from base to the drilling site, during operations. A provision will be made 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 60 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 Well spudding 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 and this process is 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.
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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.
2.6.2 Drilling Activity
ONGC will appoint a Drilling Contractor to carry out the drilling work. To support the drilling operation, the following systems and services will be included at the rig package: Environmental Protection – Blow Out Prevention (BOP) system, wastewater treatment unit, cuttings handling equipment.
Drilling of Well The exploitation of hydrocarbons requires the construction of a conduit between the surface and reservoir. This is achieved by the drilling process. The exploration well 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 3000 meters as planned for the project. The typical configuration of a Drilling Rig is shown in the Figure 2.15.
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FIGURE 2-15: 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 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 exploratory 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
SENES/K-20200/December 2013 41 ONGC EIA Studies for Exploratory drilling at Pre-NELP Block AA-ONJ/2 problematic. The ingredient of water based drilling fluid is given in Annexure 2.2. Special additives used and their function in water based drilling fluid is presented in Annexure 2.3. However in formations where water based mud will not be suitable, an eco-friendly synthetic based mud will be used. 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 and will be thoroughly washed. Cuttings will then be stored in the HDPE lined pits (of approximately 140 m3 capacity) and after completion of the drilling activities, cuttings will be tested for hazardous nature. Based on nature of drill cuttings, final disposal pathway will be finalized by ONGC. The total amount of cuttings produced during the entire drilling period is projected to be about 250-300 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. 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 2.16 shows the schematic layout of the drilling waste management. Figure 2.17 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 Srikona. Additionally, chemicals will also be stored in the drill site. The storage area will be paved and bunded and will be provided with a shed.
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Drilling Operation
Drilling mud separation in Drill cuttings plus drilling shale shaker mud
Drilling mud reused
Washed & oil free drill cuttings to
HDPE lined drill cutting pit
Drill cutting washing
Disposal after testing & treatment to Washed waste water to HDPE meet regulatory requirement lined waste water pit
FIGURE 2-16: DRILLING WASTE MANAGEMENT SYSTEM
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FIGURE 2-17: 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 Testing 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 company will be entrusted with the job of well logging. Logging instruments (sensors) will be attached to the bottom of a wire line and lowered to the bottom of the well. Sensors are then slowly pulled out. Readings of every well are given in form of graphical representations, which can be interpreted by the geologist, geophysicist and drilling engineer. There are no emissions to the environment associated with wire line logging operations. It is to be mentioned here that, if produced oil is generated during the well testing, the same will be stored in designated oil pit before disposing it off to authorized used oil handlers.
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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 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 few wellhead equipment (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 on 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 10-15 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 60 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 as per the regulatory requirements. All other waste products, solid and liquid, will be disposed off in accordance with the requirements of the EIA as specified in Sec 2.8 & 2.9 and will be treated to render them harmless as per Sl.No.72, Schedule I – Standards for Emission or Discharge of Environmental Pollutants from Oil Drilling Gas Extraction Industries. 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.
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 overlaying on the
SENES/K-20200/December 2013 45 ONGC EIA Studies for Exploratory drilling at Pre-NELP Block AA-ONJ/2 de-compacted site with certain moisture conservation measures and seeding of leguminous plant for restoration of soil nutrient level naturally.
2.7 UTILITIES & RESOURCE REQUIREMENTS
2.7.1 Power Supply Drilling being a continuous process, power requirement during this phase will be met through 3 Nos. of DG Sets (AC-SCR Type) of capacity 750KW each. Although drilling operations will be continuous, power requirement will vary depending on activities carried out. It is anticipated that, two DG sets will be required for drilling purposes and extra one will be kept as standbys. The DG Set would have a stack height of approximately 5.5m.
2.7.2 Water Consumption and Supply The water requirement in drilling rig is mainly meant for preparation of drilling mud apart from washings and domestic use. While former constitutes majority of water requirement, latter or the water requirement for domestic and wash use is minor. Water for both process and domestic uses would be procured through surface water sources. The daily water consumption will be 20m3/day out of which, 10m3/d will be used for mud preparation. The water requirement per well is shown in Table 2.5.
TABLE 2-5: WATER REQUIREMENT PER WELL
Description Quantity Total Water Requirement during Drilling Phase (KL) 900(@20m3/day) No. of Days on well 45 Average drilling water consumption per day (KLD) 20
Provision of storage of water will be made on site. Tankers will be deployed in site to meet the requirement during peak demanding period. Potable water requirement at site will be met through 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 surface water. The water balance diagram is provided as Figure 2.17
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Water sourced from surface water sources (20m3/day)
/d
/d
3 3
m
10 m 10 10
Rig wash Mud
Preparation
/d
3
9 m 9
Treated at ETP to conform to CPCB HDPE discharge standards Lined Pit
Reused & Recycled
FIGURE 2-18: WATER BALANCE DIAGRAM
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2.7.3 Fuel Consumption and Storage Fuel consumed during the drilling phase will mainly be diesel used by rig for exploratory drilling, various equipments and vehicles operating to transport goods and supplies to site. It is estimated that, about 1-1.5 KLD diesel will be required to power the off-road construction equipment and vehicles during site preparation phase. High Speed Diesel (HSD) will be used as fuel for running captive gensets in rig, various equipments and vehicles operating to transport goods and supplies to the site. During the drilling phase, the consumption of diesel by the drilling rig will be about 6 KL/day. 85% of the fuel will be used for rig operation and 15% will be used in the campsite. A reserve of 7 days, approximately 42 KL of fuel will be stored at onsite storage facility as per Petroleum Rule, 2002. The storage area will be paved and will be having bund wall. Shed will also be provided at the diesel storage area.
2.7.4 Manpower / Employment The project will be employing considerable manpower for all the phases. During the site preparation, 45-50 workmen will be employed per drill site. During the drilling phase, about 50 workmen in two shifts will be employed on site. This will include technical experts, who will be responsible for various drilling related activities and some local workmen (10-15 Nos.) will be hired from the nearby villages in entire duration of project. It is also anticipated that, at any given time, there will be 22-25 personnel working on site including technical staff, drilling crew, security staff etc.
2.8 POLLUTION SOURCES AND CHARACTERIZATION
2.8.1 Noise and Vibrations Noise will be emitted from exploratory drill site during site preparation, drilling and decommissioning phases. The major noise generating operations from the proposed activity includes 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 the Table 2.6 and Table 2.7 respectively. Table 2-6: Construction Equipment Noise Level 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
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Sound Level At Operator (in decibels) Equipment Average Range 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 2-7: 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 are expected 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 campsite. The principle pollutants will comprise of Particulate Matter (PM),
Sulphur and Nitrogen dioxides (SO2 and NO2) and other hydrocarbons (HC). H2S will not be emitted from the process operation. The quantity of diesel consumed during drilling will be in order of 4-6 KL /day/drilling site. Additionally, flaring and burning of oil during testing of the well will also lead to 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. Additionally, there will be re- entrainment of dust from the approach road leading to the site mainly during dry season.
2.8.3 Waste water Treatment and Disposal During drilling operations, approximately 9-10m3 of drilling waste water will be generated during the entire period as a result of rig wash and dewatering of spent mud, effluents from washing of drill cuttings, floor washings, pump, seal leakages etc. The characteristics of drilling and wash wastewater will be primarily dependent on type and composition of drilling fluid used for drilling. As ONGC is proposing the use of water-based drilling mud, the
SENES/K-20200/ December 2013 49 ONGC. EIA Studies for Exploratory drilling at Pre-NELP Block AA-ONJ/2 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 recycled through a mobile Effluent Treatment Plant installed at the drilling site. The plant will be capable of handling 125m3/day of drilling effluents. Domestic waste water generated (about 8m3 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 2.8.
TABLE 2-8: LIQUID WASTES GENERATED DURING DRILLING AND THEIR DISPOSAL Waste Type Quantity Disposal The water will be adequately treated in a mobile ETP to ensure conformance to The water will be Drilling and 9-10 m3 per adequately treated in a mobile ETP to ensure wash conformance to the S No. 72 A (ii) Schedule I day Wastewater Standards for Emission or Discharge of Environmental Pollutants from Oil Drilling and Gas Extraction Industry of CPCB 8.0 m3 per Domestic day from Septic tank followed by soak pit Wastewater drilling site
2.8.4 Generation, Treatment and Disposal of Solid Waste (Hazardous and Non- Hazardous) The different solid and hazardous waste streams generated during drilling and their disposal methodology has been presented in Table 2.9.
TABLE 2-9: WASTE STREAMS GENERATED DURING DRILLING AND THEIR DISPOSAL
Waste Type Quantity Characteristics Treatment (If required) and Disposal Kitchen Waste 10 – 20 kg Organic waste Will be stored in compost pits on a per day (Non HW) daily basis. Drill Cuttings 250-300 Mainly Inert material Drill cuttings will be disposed off in a 3 m / well Consisting of Shale, well designed pit lined with impervious liner located on site as per S No. 72 Sands and clay; about C.1.a Schedule I Standards for 1% of drilling mud. Emission or Discharge of (Non HW) Environmental Pollutants from Oil Drilling and Gas Extraction Industry of CPCB as modified in 2005. Waste Drilling 3000 m3 Barite, Bentonite and The mud will be tested for hazardous Mud for each Traces of contaminants and will be disposed as (Fluid) well Heavy metals (HW) per S No. 72 C.1.a Schedule I Standards for Emission or Discharge of Environmental Pollutants from Oil Drilling and Gas Extraction Industry of CPCB as modified in 2005
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Waste Type Quantity Characteristics Treatment (If required) and Disposal Acid – Lead 2 – 3 Lead – Acid (HW) Will be recycled through the vendors Batteries Batteries supplying acid – lead batteries as per required under the Batteries (Management & Handling) Rules, drilling of 2001. well Oily waste- 0.3 m3 Used & Waste oil Will be collected in metal drums kept used oil & 5-10 Kg in secured dyked area & Disposed as spent Oil and per Used oil rules in approved used oil 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 of oil and gas. Effective response plans to foreseeable emergencies will be developed by ONGC and communicated to the project teams. A risk assessment will be carried out because part of this EIA will also include identification of hazards, risks and formulating management plans for emergency response, blowout, oil spills.
2.10 PROJECT COST Based on ONGC’s experience, total cost for drilling of 9 exploratory wells will be approximately INR 270 crores which includes daily drilling rates, consumables, well accessories etc. The cost of drilling will depends on depth of the well to be drilled.
2.11 HSE POLICY ONGC 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 range of operations it undertakes as a part of oil and gas exploration. The overall corporate health environmental safety policy of ONGC may be supplemented by a local policy document whenever so required. It is understood that, ONGC will try to formulate a local site level policy taking from the parent corporate policy of ONGC to adequately address the environmental impacts of the proposed drilling projects in AA-ONJ/2 Block through the DMS.
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3 Description of the Environment
This chapter describes the existing environmental settings in the AA-ONJ/2 Block 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. All the environment component monitoring i.e. Meteorology, Air, Noise, Soil, Ground water, Surface water will be conducted by Mitra SK Private Limited (A NABL Certified Laboratory). All monitoring at field were undertaken under the guidance and supervision of SENES personnel during pre-monsoon months of May-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 AA-ONJ/2. 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.
Seasons Based on the analysis of meteorological data, details of climatological profile have been presented below: (Refer Annexure 3.1).
Temperature Interpretation of Primary Baseline Data Micrometeorological data obtained for temperature as part of climatological monitoring undertaken for the proposed project during pre monsoon season revealed the daily maximum and minimum temperature at 43.5°C and 25.0 °C respectively. The micrometeorological values recorded for temperature have been provided in Annexure 3.1
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Relative Humidity Interpretation of Primary Baseline Data Daily maximum and minimum Relative Humidity (RH) was recorded at 23% and 96% respectively during the primary monitoring study. The hourly variation of average relative humidity has been listed in Annexure 3.1.
Rainfall Interpretation of Primary Baseline Data About 37.2 mm of total rainfall was recorded during primary monitoring period. Maximum rainfall with 5.3mm was recorded during the study period. The micrometeorological values recorded for rainfall have been provided in Annexure 3.1 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 has been analyzed to generate the pre monsoon season wind rose. The predominant wind direction was observed to be from West South West for the study period. The average wind speed for the months was 1.28 m/s. The wind speed was observed primarily in the range 0.56 – 3.89 m/s for the monitoring period. The calm frequency was recorded as 13.58%. The wind rose diagram generated for the primary monitoring study period and wind class frequency distribution have been presented in Figures 3.1 and 3.2 and wind speed & wind direction data have been provided as Annexure 3.1 for reference.
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FIGURE 3-1: WIND ROSE DIAGRAM FOR PRE-MONSOON SEASON
FIGURE 3-2: WIND CLASS FREQUENCY DISTRIBUTION
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 to the receptors located at that end. Thus the analyzed values for the pre project environment can be compared during and after the
SENES/K-20200/ December 2013 54 ONGC. EIA Studies for Exploratory drilling at Pre-NELP Block AA-ONJ/2 project activities. The major sources of air emission are 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. 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
Ambient air quality monitoring was conducted at 8 representative locations during May-June 2013. The number of monitoring stations and parameters for monitoring were based on the approved ToR obtained from MoEF. Air quality monitoring was carried during the pre-monsoon season, 24 hours a day twice a week for PM10, 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- 460BL, Envirotech Instruments Pvt. Ltd) was used for sampling of PM10, SO2 and
NO2.
Rationale for selection of air monitoring stations The ambient air quality monitoring locations have been selected based on topography and prevailing micro-meteorological conditions (downwind, upwind and crosswind directions) to establish baseline ambient air quality in areas likely to be affected the exhaust emissions from DG sets, movement of vehicles, fugitive emissions from material stockpiles and from sourcing & transportation of raw materials during project construction phase. Flaring of gases under emergency situation during operational phase has also been considered in this regard. A screening model was run before the selection of the stations with SCREEN 3 and maximum GLC was found to be within 2 km of the well sites considering all stability classes. Monitoring locations were selected based on upwind, downwind and crosswind directions of the proposed well sites at set settlements and sensitive receptors that are likely to be affected by the drilling operations. As the Block is distributed between Assam, Manipur and Mizoram monitoring stations were selected in all three states. As majority of the wells are located at Assam 6 monitoring locations are selected at Assam. One air quality station was selected in each of the states Manipur and Mizoram as there are few wells viz. one in Manipur and two in Mizoram. Other considerations like accessibility to the monitoring location, availability of stable electric connection for running of RDS and safety and security of machine and monitoring personnel were also considered while selecting the monitoring locations. The concentrations of various pollutants were processed for different statistical parameters like arithmetic mean, minimum concentration, maximum concentration and percentile values. Rationales for selection of Monitoring Location are given in Annexure 3.2 and detailed ambient air quality results are presented in Annexure 3.3.
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Interpretation of Air Quality Results
Particulate Matter (PM10): The 24 hourly PM 10 concentration at the monitoring locations ranged between 44-63 μg/m3 (Figure 3.3) which is well within the NAAQS (100 μg/m3).
Detailed ambient air quality results in terms of PM 10 are presented in Annexure 3.3.
FIGURE 3-3: AVERAGE PM 10 VALUES AT THE MONITORING LOCATIONS
Nitrogen dioxide (NO2): The NO2 values at the monitoring locations were observed in the range of 19.2-24.8 μg/m3 (Refer Figure 3.4) which is well within the NAAQS (80 μg/m3).
Detailed ambient air quality results in terms of concentration of NO2 are presented in Annexure 3.3
FIGURE 3-4: AVERAGE NO2 VALUES AT THE MONITORING LOCATIONS
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Sulfur dioxide (SO2): Sulfur dioxide concentrations at the monitoring location ranges from 4.8-6.6 μg/m3 (Refer Figure 3.5) and is well within the NAAQS (80 μg/m3). Detailed ambient air quality results in terms of concentration of SO2 are presented in Annexure 3.3
FIGURE 3-5: AVERAGE SO2 VALUES AT THE MONITORING LOCATION
Methane and Non- Methane Hydrocarbon: Average values for methane hydrocarbons at the sampling stations varied between 1.0-1.21 ppm whereas the concentration of non-methane hydrocarbon at all sampling location found to be <0.5 ppm. Volatile Organic Carbon (VOCs): VOC concentration of all the sampling location were found to be <2.8 μg/m3). Average Hydrocarbon (Methane and Non-methane) and VOC monitoring data are presented in Table 3.1.
Photo 3-1: Air Monitoring near Karkat Basti
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TABLE 3-1: AVERAGE HYDROCARBON AND VOC MONITORING DATA Methane Non-methane Sl. Monitoring VOC hydrocarbon hydrocarbon No Locations (μg/m3) (ppm) (ppm) 1 Tulagram Part II 1.03 <0.5 <2.8 2 Bidyaratanpur 1.2 <0.5 <2.8 3 Niz Rupai Bali 1.09 <0.5 <2.8 4 Pabda Basti 1.11 <0.5 <2.8 5 Hmarkhawlien 1.09 <0.5 <2.8 6 Jiribam 1.21 <0.5 <2.8 7 Saiphai Basti 1.00 <0.5 <2.8 8 Binnakandi Tea Estate 1.19 <0.5 <2.8
3.1.3 Ambient Noise Quality The ambient noise monitoring was conducted during the pre monsoon season of 2013 at 8 locations viz. Tulagram Part II, Bidyaratanpur, Niz Rupai Bali, Pabda Basti, Hmarkhawlien, Saipum Basti, Latingkhal and Binnakandi Tea Estate within the AA-ONJ/2 Block. Noise stations were selected near to the proposed exploratory 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 Rules1. The ambient noise quality monitoring locations within the study area are shown in Figure 3.7.
Interpretation of Noise Quality Results The day time noise levels at all the noise monitoring station is found well within the day time standards (55 decibels) for residential area. Similarly night time noise levels are also within the night time noise standards for residential area (45 decibels). Rationale for selection of monitoring location is presented on Annexure 3.2 and the detailed noise monitoring results is presented in Annexure 3.4.
1 Sound Level Meter: SL 4001, Lutron & SLM 100, Envirotech CPL-4, 11
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FIGURE 3-6: DAY AND NIGHT TIME EQUIVALENT NOISE LEVELS
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FIGURE 3-7: LOCATION OF AIR, NOISE AND METEOROLOGY MONITORING LOCATIONS WITHIN THE AA-ONJ/2 BLOCK
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3.1.4 Physiography and Geology
Physiography The basement of NE India comprises various Gondwana fragments, mainly peninsular India and the West Burma Block, with the Lhasa and Sibumasu Block framing the regional picture. The present day basin reflects three distinct tectonic phases. The earliest was late cretaceous to Eocene block faulting and development of a northern easterly dipping shelf. During the second phase, in Oligocene time, uplift and erosion occurred north of the Dukai fault, many basement fault was reactivated and many basement controlled structures became prominent. (Naidu and Panda, 1997). Late Miocene through Pliocene, extensive alluvial deposition followed Oligocene uplift and erosion.
District Geology The geology of Cachar district can be divided into two groups, i.e. unconsolidated deposits comprising alluvial deposits of Sub-recent to recent age and semi-consolidated Tertiary deposits of Bhaban, Bokabil, Girujan/Tipam, Duptilia and Dihing formations of Miocene and Pliocene age. The alluvial deposits present in the central part mainly comprise of sand, silt and clay with gravel and occasional coal bands. The semi-consolidated rocks are exposed in the form of hillocks comprising shale, sandstone, ferruginous sandstone, mottle clay, pebble bed and boulder beds etc. (Source: Ground water information booklet, Cachar district, Assam, November, 2008) Imphal East (Jiribam) district is mostly occupied by semi-consolidated formations which cover almost the entire area. It comprises shale, sandstone, siltstone and conglomerate. These formations belong to Disang, Barail, Surma and Tipam group of rocks. (Source: Ground water information booklet, Imphal East District, Assam, May, 2009). The geology of Aizawl district mainly comprises of north-south aligned Aizawl Main Ridge from Bawngkawn in the north to Tuikhuhtlang in the south. The Aizawl main ridge comprises compact siltstone/fine sandstone, underlain by soft siltstone/shale (Rawat and Deva, 2001).Siltstone/sandstone beds occur conspicuously in the upper part of the Aizawl main ridge and in the deep slopes of the eastern side while the soft siltstones/shale is exposed at lower elevations. The rocks of the Aizawl main ridge belong to Bhuban sub group (Lower and middle Bhuban formations) of the tertiary Surma group forming a part of Aizawl-Sialsuk anticline. While the middle Bhuban formation is predominantly arenaceous comprising medium to fine grained, compact, well bedded sandstone and siltstone with interbedded silt/shale interlaminated units, the lower Bhuban formation is predominantly argillaceous and include moderately compact medium to fine grained sandstone with shale and silt/shale intercacalations. (Source: A feasibility study for urban tunneling in soft tertiary sedimentary rocks of Mizoram, India by Yogendra Deva and U.S Rawat) On the other hand, the area of Kolasib district is mainly represented by two main ridge lines and intervening valleys and less prominent linear ridges. The most prominent ridge runs in
SENES/K-20200/December 2013 61 ONGC EIA Studies for Exploratory drilling at Pre-NELP Block AA-ONJ/2 almost North-South direction through the entire area except for few saddles that breaks the range. The average height of the ridge decreases from south to north. On the eastern side of the Main ridge, runs a parallel ridge from Nisapui tlang towards Lungmuat tlang upto Bukpui. On a slightly eastern side, the ridge runs from Kangmual to Hlimen and continues all the way to Parsenchhip and joins Telchat tlang and continues towards Saipum village. The north western extremity of this range is bounded by Saichang tlang which joins with Teidung tlang on the south. Like the ridge on the western side, the height of this ridge decreases towards north. Towards the eastern side of this ridge line flows the Tuirial river, and most of the spurs run from the ridge towards this river. (Source: District Disaster Management Plan, Kolasib District, 2009).
Block Geology Geological mapping of the block identified three exposed structures, i.e. Ramphan, Bhuban and Teidukhan. Ramphan Anticline: Upper Bhuban is exposed in the core. On the other hand, Lower Bhuban and Renji may be prospective in view of proximity to Labak syncline. Bhuban Anticline: It is situated at the south of Ramphan anticline. Middle Bhuban is exposed in the core of the anticline. It has gentle crestal area. Lower Bhuban and Renji may be prospective in view of proximity to Labak syncline at shallower depth. Teidukhan Anticline: Northern part of the structure lies in the block, where Bokabil formation is exposed. Entrapment is envisaged by intersection of cross trend with anticlinal trend. An exploratory location has been released in the prospect adjacent to the block. Rising flank of Labak Syncline: Rising flank of Labak syncline may be prospective due to due to proximity to the proved source kitchen. In Manipur province of the block, structures like Tenghil Anticline (Lower Bhuban formation in the core)
3.1.5 Hydrogeology The entire area of Cachar district is represented by unconsolidated, semi-consolidated and consolidated formations and these units are as follows: 1. Very compact formation comprising the Surma and Dihing series of rocks. 2. Semi-consolidated rocks comprising Tipam ad Duptilia formations and, 3. Unconsolidated formation of alluvial deposits. The semi-consolidated Tipam sandstones form good repository in the area. The depth to water level varies from a few meters to 4m bgl in alluvial sediments particularly in north and south of Silchar and in western parts while it varies from a few metres to 2m bgl in the central parts. The hydraulic gradient of ground water is from North to South in northern parts and ground water flows from south to north-west in southern parts. The static water level in
SENES/K-20200/December 2013 62 ONGC EIA Studies for Exploratory drilling at Pre-NELP Block AA-ONJ/2 shallow aquifers (within 5m) is within 1.3 to 4.0 m bgl in the north of the Barak River and it varies from 1.8 to 2.22 m bgl in southern parts. In the deeper aquifer, the granular zone occurs below a confining layer of clay, thus it is a confined aquifer. The static water level ranges from 1.92 to 6.88 m bgl in northern parts and from 0.50 to 8.50 m bgl in southern part of the river Barak. The water level fluctuation is generally less than 1 m; however, in places like Srikona, Mohanpur, Rajabazar and Kashipur, it is from 4.52 to 7.0m. In the central part of the district around Dholai, Palanghat etc. it is only 0.20 m indicating low fluctuation in fine grained deposits.(Source: Ground water information booklet, Cachar district, Assam, November, 2008). On the other hand, the aquifer thickness ranges from 10-20m bgl in Imphal East district. Ground water is found to occur at a depth of 22.35m bgl during pre-monsoon period and it is upto 11.92m bgl during post monsoon period. (Source: Ground water information booklet, Imphal East District, Assam, May, 2009).
Ground Water Resources The estimated gross annual dynamic ground water resource of the district is 2,239.21 mcm while the net annual ground water draft is 32.65 mcm. The stage of ground water development is only 2% and it represents a nascent stage. The projected demand for domestic and industrial use up to 2025 is only 52.46 mcm. The district comes under “SAFE” category as per CGWB report. (Source: Ground water information booklet, Cachar district, Assam, November, 2008). On the other hand, annual replenishable ground water sources as on 2004 in Imphal East (Jiribam) district is 85.68mcm while the net annual ground water draft is 0.42 mcm. The stage of ground water development is only 0.49%. The projected demand for domestic and industrial use is up to 5.42 mcm. The district comes under “SAFE” category as per CGWB report. (Source: Ground water information booklet, Imphal East District, Manipur, May, 2009). Groundwater is primarily used for drinking and other domestic purposes. Groundwater is primarily tapped by tube wells and dug wells.
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 aquifer. Contamination of aquifers may also occur from disposal of drilling waste and mud in an open/unpaved pit.
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A monitoring network consisting of 6 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 3.2.
Ground Water Sampling Points A total of 4 nos. ground water samples were collected from the study area villages comprising of Phulertol, Pabda Basti, Bidyaratanpur, Mejhirgham, Saipum Basti and Latingkhal. 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 all the sampling location exceeded both required limit and permissible (in absence of an alternative source) limit specified under IS: 10500 standard. Turbidity value ranges from 14.5 NTU in the sample collected from Bidyaratanpur to 136 NTU in the sample collected from Mejhirgram. High turbidity therefore could possibly result in the decrease in the acceptability of such water for potable purposes. Chlorides and Total Dissolved Solids With respect to IS: 10500 standards the required 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 3.88 mg/l (Latingkhal) and 31.54 mg/l (Pabda Basti). 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 most desirable 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 32.2 mg/l at Saipum Basti to 258.0 mg/l at Phulertol thereby conforming to the required limit of this ground water parameter. 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 24.96 mg/l (Pabda Basti) to 156.0 mg/l (Phulertol) 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
SENES/K-20200/December 2013 64 ONGC EIA Studies for Exploratory drilling at Pre-NELP Block AA-ONJ/2 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 required 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 all location (except Saipum Basti 0.16 mg/l) exceeds the required limit as per IS 10500 standard. Higher iron concentrations at samples range from 1.01 mg/l (Bidyaratanpur) to 25.81mg/l (Mejhirgram). 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 limit of the potable drinking water standard of 1.0 mg/l. 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 four sources were found to be below detection limits. Coliforms Coliforms are indicators of contamination from sewage and faecal matter. Coliforms were present in all collected samples and in the concentration of 350 MPN/100ml in the sample collected from Phulertol, 7MPN/100ml in the sample collected from Pabda Basti, 90 MPN/100ml in the sample collected from Bidyaratanpur, <2MPN/100ml in the sample collected from Mejhirgram, 14 MPN/100ml at Saipum Basti and 8 MPN/100 ml in Latingkhal. Faecal coliform were detected in ground water sample taken at Bidyaratanpur.
Photo 3-2: Groundwater sampling at Pabda Photo 3-3: Groundwater sampling at Majhigram Basti LP School
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TABLE 3-2: GROUNDWATER MONITORING RESULTS
IS: 10500: 2012 Bidyaratanp Mejhirgram Sibananda Tilka Primary ur LP School, Permissibl Buniyadi SL. e limit in School, (Ring Well) Mejhirgram Saipum Basti Latingkhal Test Parameters Required Unit Bidyalaya, No. the Pabda Basti (Hand (Tube well) (Tube well) (Acceptabl absence of Phulertol e Limit) (Dug Well) Pump) alternative (Tube Well) source 1 pH No 7.0 6.0 6.3 6.1 6.82 7.01 6.5-8.5 relaxation 2 Colour 5 15 Hazen <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 3 Odour - Unobjectiona Unobjectionabl Unobjectiona Unobjectiona Unobjectiona Unobjectionabl Agreeable Agreeable ble e ble ble ble e 4 Turbidity 1 5 NTU 46.9 53 14.5 136 26 42 5 Total Hardness as mg/l 156 24.96 41.6 45.76 25.54 51.07 200 600 CaCO3 6 Calcium as Ca 75 200 mg/l 33.28 6.66 11.65 3.33 5.1 10.21 7 Magnesium as Mg 30 100 mg/l 17.47 1.99 2.99 8.98 3.06 6.13 8 Alkalinity 200 600 mg/l 235 35 55 140 17.39 47.83 9 Chlorides as Cl 250 1000 mg/l 13.79 31.54 7.88 3.94 7.76 3.88
10 Sulphate as SO4 200 400 mg/l <1.0 1.5 <1.0 <1.0 <1.0 <1.0
11 Nitrate as NO3 No mg/l 5.02 4.31 1.39 1.46 <0.5 <0.5 45 relaxation 12 Copper as Cu 0.05 1.5 mg/l <0.02 <0.02 <0.02 <0.02 <0.02 <0.02 13 Iron as Fe 0.3 mg/l 5.67 3.23 1.01 25.81 0.16 1.71 14 Fluorides as F 1.0 1.5 mg/l 0.3 <0.1 0.12 0.29 <0.10 <0.10 15 Zinc as Zn 5 15 mg/l <0.02 <0.02 <0.02 0.033 <0.02 <0.02 16 Phenolic Compound 0.001 0.002 mg/l <0.001 <0.001 <0.001 <0.001 <0.001 <0.001
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IS: 10500: 2012 Bidyaratanp Mejhirgram Sibananda Tilka Primary ur LP School, Permissibl Buniyadi SL. e limit in School, (Ring Well) Mejhirgram Saipum Basti Latingkhal Test Parameters Required Unit Bidyalaya, No. the Pabda Basti (Hand (Tube well) (Tube well) (Acceptabl absence of Phulertol e Limit) (Dug Well) Pump) alternative (Tube Well) source 17 Mercury as Hg No mg/l <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 0.001 relaxation 18 Cadmium as Cd No mg/l <0.002 <0.002 <0.002 <0.002 <0.002 <0.002 0.003 relaxation 19 Arsenic as As 0.01 0.05 mg/l <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 20 Lead as Pb No mg/l <0.005 <0.005 <0.005 0.014 <0.005 0.014 0.01 relaxation 21 Hexavalent 0.05 (for mg/l <0.05 <0.05 <0.05 <0.05 <0.05 <0.05 +6 No Chromium as Cr Total relaxation Chromium) 22 Total Dissolved mg/l 258 90.3 75.37 145 32.2 59.6 500 2000 Solids 23 Total Coliform Shall not be detectable in (MPN/ 350 7 90 <2 14 8 Organism any 100 ml sample 100ml) 24 Faecal Shall not be detectable in /100ml Absent Absent Present Absent Absent Absent coliform/100ml any 100 ml sample
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FIGURE 3-8: LOCATION OF GROUNDWATER, SURFACE WATER AND SOIL MONITORING LOCATIONS WITHIN THE AA-ONJ/2 BLOCK
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3.1.7 Watershed and Drainage The study area is included under the catchment of Barak River. The channels traversing through the field in included under the sub-water sheds of Barak River viz. Sonai River, Rukni River, Jiri River and Chiri River. Apart from this, some local water channels i.e. Lating Khal, Mach Khal and Naga Khal are flowing thorough the block. The drainage pattern of the major rivers traversing the study area is discussed below: Te drainage and watershed map of the block is given in Figure 3.9 Barak River The river rises in the hill country of Manipur state. After its origin, it flows in western direction through Manipur and then taken its course in south western direction to enter Mizoram state. In Mizoram state, the Barak flows southwest then veers abruptly north when joined by a north flowing stream and flows into Assam state. Then it turns westward again near Lakhipur as it enters into the plain. It then flows west past the Silchar town where it is joined by the Madhura river. After Silchar, the river flows for about 30kilometers and just west to Badarpur, it enters Bangladesh and its mouth divides into Surma River and Kushiyara River. The river initially flows towards the northern direction of the block and then takes its course towards west near Lakhipur and finally leaving the block near Saidpur. Sonai/Tuirial River Sonai/Tuirial is the tributary of Barak River. The river flows through the middle of the block and runs towards the northern boundary. The river runs parallel to the Barak River before merging with it near Sonabarighat. Jiri River Jiri River initially passes through the eastern boundary of the block and enters in Assam near Jirighat. After that, the river takes its turn towards south and passes through Nungphou, Latingkhal villages before merging with Barak River near Jirimukh. Rukni River This river flows along the western side of the block boundary and enters into the block near Bhaga. The river ultimately merges with Sonai River near Kabuganj. Chiri River This river flows along the northern side of the block boundary and a minute portion of this river comes into the block boundary near Singerbond. The river ultimately merges with Barak River near Chandrapur Part IV village. The approximate distance of major rivers from the well sites are presented in the Table 3.3.
TABLE 3-3: DISTANCE OF WELL SITES FROM NEAREST RIVER Name of Well Nearest River Distance RBK-1 Sonai 0.75km RBK-2 Barak 1.75 km
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Name of Well Nearest River Distance RPAA Barak 0.65 km RBK-3 Barak 2.65km RLBK-1 Barak 3.00km RTDN-1 Rukni 4.50km RJDR Jiri 0.4km RTDN-2 Sonai/Tuirial 3.00km RTNG-1 Barak 2.1km
The drainage map of the study area is presented in Figure 3.8 These surface water channels within the Block are primarily used for irrigation, bathing, washing and for catching fish. Surface run-off and discharge of drilling wastewater from the proposed exploratory wells located close to these rivers have the potential to affect the water quality. The wells located at the sub-water shed have been provided at Table 3.4 and shown at Figure 3.8.
Photo 3-4: Rukni River Photo 3-5: Jiri River
Photo 3-6: Sonai River Photo 3-7: Barak River
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FIGURE 3-9: DRAINAGE AND WATERSHED MAP
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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 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 activities. A monitoring network consisting of 4 locations for surface water monitoring were selected at the water shed of Barak River and its sub-watersheds viz. Rukni River and Sonai River. Sampling and analysis2 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. Upstream of Barak River, Sonai river and Rukni river. As all these water courses ultimately unite with Barak River, therefore another sample was collected from the downstream of Barak River 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 6.7-7.1. The DO levels at all the locations exhibited values ranging from 3.6-7.8 mg/l. The low value of DO in Rukni River could be due to mud laden surface runoff from local catchment area. BOD values in all the surface water samples were detected at concentration between <2.0- 9.88mg/l-3.00 mg/l whereas COD value ranges between 7.72-30.89mg/l. The reason behind high value of BOD and COD in Rukni River can be due to mud laden surface runoff. Electrical conductivity values of the samples ranged between 53.7-76.6 microsiemens/cm, sodium absorption ratio varied between 0.21-0.34. Free ammonia contents of all the samples were found to be less than 0.1 mg/l. Chloride and nitrate content of all collected surface water sample ranges from 1.97-3.94mg/lit and 0.9-1.73 mg/lit respectively. The total coliform count of the surface water samples varied between (02MPN/100ml) at Upstream of Barak River to 900 MPN/100ml at Rukni River. The presence of contaminants in the form of oil and grease in all surface water sources was found to be negligible. Iron content on all the surface water sample varies from 6.8- 37.68mg/lit whereas chromium content was found to be negligible. The toxic organic
2 http://www.cpcb.nic.in/latest/guidelines-water.doc
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TABLE 3-4: SURFACE WATER QUALITY RESULTS
Upstrea Downstrea SL. m of Sonai Test Parameters Unit m of Barak Rukni No. Barak River River River River 1. Temperature 0C 29 28 29 28 2. Free Ammonia mg/l <0.1 <0.1 <0.1 <0.1 3. Total Coliform (MPN/100ml) 2 80 80 900 4. pH at 270C - 7.1 7.0 7.0 6.7 5. Dissolved Oxygen mg/l 7.8 5.1 6.7 3.6 6. BOD (3 days at 270C) mg/l <2.0 3.2 3 9.88 7. Electrical Conductivity µs/cm 71.1 70.8 76.6 53.7 at 250C 8. Sodium Absorption mg/l 0.34 0.34 0.34 0.21 Ratio 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 Solids mg/l 47.2 46.8 50.3 33.9 12. Total Suspended Solids mg/l 139.4 322.6 126.6 976.4 13. Dissolved Phosphate mg/l <0.15 <0.15 <0.15 <0.15
14. Nitrate as NO3 mg/l 1.22 1.16 0.9 1.73 15. Chlorides as Cl mg/l 3.94 3.94 3.94 1.97
16. Sulphate as SO4 mg/l <1.0 <1.0 <1.0 <1.0 17. Iron mg/l 6.8 17.59 6.88 37.61 18. Total Chromium mg/l <0.01 0.013 0.045 0.033 19. COD mg/l 7.72 15.44 11.58 30.89 20. Phenolics mg/l <0.001 <0.001 <0.001 <0.001
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Photo 3-8: Surface water sampling from Upstream of Photo 3-9: Surface water sampling from Rukni River Barak River
3.1.9 Land-Use The land-use and land-cover of the study area 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 (76.5%) in the area is forest land. 12.36% land is used for agricultural purposes. 9.14% of land is occupied by settlements whereas tea garden constitutes only 0.04% of the total land. River, Riverbeds and water bodies constitutes 2.09% of total land. Roads including NH-53, NH-54 along with the other access roads i.e. Sonai Road, NEEPCO-Tuirial Road constitutes 0.11% of the total land. 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 DISTRIBUTION OF STUDY AREA
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FIGURE 3-11: LAND USE MAP OF AA-ONJ/2 BLOCK
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3.1.10 Soil Quality The major soil types found in Cachar district can be categorized as follows: Non Laterized Red Soil: This type of soil is confined in hilly areas and is more acidic than alluvial tract. Old mountain alluvium Old Riverine Alluvium: This type of soil is deep to heavy textured varying from silt to clay loam with moderate organic matter content. Lateritic Red Soil: This type of soil is sandy loamy in texture varying from sandy to fine silty loam. Silt deposition is common feature of this type of soil with comparatively higher pH. Peat Soil: This type of soil is heavy textured, dark grey in colour with high organic matter content. (Source: Agriculture Contingency Plan of Cachar District). Two major types of soils are found in Imphal East district i.e. residual and organic which cover both the hill and plain. The residual soils are either laterized or non-laterized. The laterized red soils covering an area of 2500sq km in the Barak drainage on the western slope of Manipur is also occupying in parts of Jiribam area. It contains rich portions of nitrogen and phosphate, a medium acidity and lesser amount of potash. The old alluvial soil is brought down by Barak River and their tributaries from their lateritic water ship hills. The transported soils are of two types, i.e. alluvial and organic. The alluvial soils cover 1600sq.km is also representing the soils of Imphal East district. The soils have good clayey warm texture and grey to pale brown colour. They contain a good proportion of potash and phosphate, a fair quantity of nitrogen and organic matter and are less acidic. The organic soils cover the low lying area of the valley. The soil in the area belongs to 4 orders, 8 sub orders, 13 great groups and 23 sub groups. It is observed that inceptisols are the dominant soil types followed by Utisols, Entisols and Aflasols and occupy 38.4%, 36.4% and 23.1% of the total geographical area of Manipur. Main soil classification in the valley, i.e. in parts of Imphal East district are younger alluvial soil, Older alluvial soil, Red gravely sandy and loamy soil and Piety and Saline soil. (Source: Ground Water Information Booklet, Imphal East District, Manipur) On the other hand, soil quality of Kolasib and Aizawl district is characterized by its acidic nature with pH ranging between 4.5 to 6.0. The soil is deficient in base material, medium in organic carbon, low in available phosphorous and high in potash. The predominant soil taxonomy is Hapladults and Udonthrnts wherein moisture retention capacity is very low. (Source: Comprehensive District Agriculture Plan for Kolasib District)
As discussed above, since soils of the Barak Valley, of which the exploratory block 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
SENES/K-20200/ December 2013 76 ONGC EIA Studies for Exploratory drilling at Pre-NELP Block AA-ONJ/2 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 near the settlements namely, Saipum Basti, Pabda Basti, Latingkhal, Bhitor Narayanpur and Dhanipur. As three exploratory well locations are situated in the forest land, therefore one soil sample has been collected from the forest land (Hmarkhawlien) for getting the soil quality of the forest land. Primary soil monitoring includes analysis of the heavy metals with the objective of establishing baseline values for such contaminants. The soil sampling location points are shown in Figure 3.8.
Interpretation of Soil Analysis Results Soil Quality of Agricultural Lands The texture of soil samples collected from all Agricultural land i.e. from Pabda Basti, Latingkhal, Bhitor Narayanpur and Dhanipur were found to be clayey in nature. The sand percentages of the samples were found in the range between 14.3% (Bhitor Narayanpur) to 23.6% (Dhanipur), whereas silt percentage of the collected sample was in the range of 17.9% (Bhitor Narayanpur) to 35.8% (Latingkhal). On the other hand clay percentage of the soil sample collected from agricultural land was found to be in the range of 46.3% (Latingkhal) to 67.8% (Bhitor Narayanpur). The pH level in soil samples were recorded in between 4.9-5.35 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 of Pabda Basti and Latingkhal were found to be 56.09 microsiemens/cm and 65.65 microsiemens/cm respectively whereas that of Bhitor Narayanpur and Dhanipur was in the range of 125.33 microsiemens/cm and 205.66 microsiemens/cm. The soil samples collected from agricultural lands of all locations revealed high available nitrogen content (167.3kg/ha, 128.75kg/ha, 141.62 kg/ha and 154.5 kg/ha for soil in Pabda Basti, Latingkhal, Bhitor Narayanpur and Dhanipur 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 (82.71 kg/ha, 99.26 kg/ha, 234.30 kg/ha and 64.43kg/ha), copper (13.45 kg/ha, 6.99kg/ha, 16.11kg/ha and 8.22 kg/ha), zinc (18.71 kg/ha, 19.12 kg/ha, 30.21 kg/ha and 23.20 kg/ha) and manganese (24.55 kg/ha, 148.88 kg/ha, 151.33 kg/ha and 155.80 kg/ha) observed in the soil samples taken from agricultural Lands of Pabda Basti, Latingkhal, Bhitor Narayanpur and Dhanipur respectively, 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.
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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 of Pabda Basti, Latingkhal, Bhitor Narayanpur and Dhanipur were found to be 0.16, 0.09, 0.14 and 0.10 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 (262.5 kg/ha, 350 kg/ha, 393.75 kg/ha and 350 kg/ha respectively for soil samples taken at Pabda Basti, Latingkhal, Bhitor Narayanpur and Dhanipur respectively) ions compared to sodium (62.5 kg/ha, 44.64 kg/ha, 80.35 kg/ha and 53.57 kg/ha for four soil samples). Higher Ca2+ values observed in the samples are indicative of good soil permeability and structure.
Soil Quality of Forest Land The texture of soil sample collected from Forest Land near Saipum Basti was found to be Clayey in texture. The sand percentage of the sample was found to be 24.9%, whereas silt percentage of the collected sample was found to be 25.9%. On the other hand, clay percentage of the sample collected from forest land was found to be 49.2%. The pH level in soil sample collected was recorded as 5.06 indicating strongly acidic soils as per standard soil classification. The EC value of the soil sample was 52.94 microsiemens/cm. The sample revealed high available nitrogen content i.e. 154.5kg/ha. The soil also contained organic carbon content of 0.55%. 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 (49.78kg/ha), copper (7.55 kg/ha), zinc (22.26 kg/ha) and manganese (97.54 kg/ha) observed in the soil samples taken from Forest Land near Saipum Basti 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 forest land was found to be 0.08. The detailed soil analysis results have been provided at Table 3.5.
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TABLE 3-5: SOIL ANALYSIS RESULTS
land
Pabda Pabda SL. Test Bhitor
Unit
ingkhal Dhanipur
No. Parameters Basti
Land near near Land
Lat
Narayanpur
Agricultural Agricultural Agricultural Agricultural
SaipumBasti
near near
Forest Land near near Land Forest
Land near near Land
Agricultural Land near near Land 1. Texture - Clay Clay Clay Clay Clay 2. Moisture % 20.16 19.16 24.32 19.72 18.24 3. Sand % 24.9 22.1 17.9 14.3 23.6 (W/W) 4. Silt % 25.9 22.7 35.8 17.9 24.9 (W/W) 5. Clay % 49.2 55.2 46.3 67.8 51.5 (W/W) 6. Organic Matter % 0.95 1.34 0.86 1.79 1 7. Alkalinity as mg/kg 19.2 19.2 38.4 38.4 19.2 CaCO3 8. Acidity as mg/kg Nil Nil Nil Nil Nil CaCO3 9. Specific gravity - 2.23 2.28 2.43 2.36 2.46 10. pH (1:5) at 27oC - 5.06 5.28 5.35 5.14 4.9 11. Electrical µs/cm 52.94 56.09 65.65 125.33 205.66 Conductivity at 250C 12. Available mg/kg 346.08 374.92 288.4 317.24 346.08 Nitrogen 13. Available mg/kg <3 <3 3.15 3.14 3.71 Phosphorous 14. Available mg/kg 40 40 20 100 40 Potassium 15. Available Ca mg/kg 490 588 784 882 784 16. Available Mg mg/kg 2822.4 1940.4 2822.4 4292.4 3480 17. Chloride mg/kg 73.48 48.98 73.48 48.98 48.98 18. Sulphate mg/kg 130.74 139.3 271.83 201.59 381.68 19. Total organic % 0.55 0.78 0.5 1.04 0.58 Carbon 20. Fe mg/kg 111.51 185.28 222.35 524.85 144.33 21. Cu mg/kg 16.92 30.14 15.66 36.1 18.42 22. Zn mg/kg 49.88 41.93 42.83 67.68 51.98 23. Pb mg/kg 18.6 16.8 15.6 23.4 19.2 24. Mn mg/kg 218.5 55 333.5 339 349 25. B mg/kg 0.68 0.89 0.73 <0.5 0.81
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EIA Studies for Exploratory drilling at Pre-NELP Block AA-ONJ/2
land
Pabda Pabda SL. Test Bhitor
Unit
ingkhal Dhanipur
No. Parameters Basti
Land near near Land
Lat
Narayanpur
Agricultural Agricultural Agricultural Agricultural
SaipumBasti
near near
Forest Land near near Land Forest
Land near near Land
Agricultural Land near near Land 26. Na mg/kg 80 140 100 180 120 27. Sodium - 0.08 0.16 0.09 0.14 0.10 Absorption Ratio (SAR)
Photo 3-10: Soil sampling from Agricultural Photo 3-11: Soil sampling from Agricultural Land near Bhitor Narayanpur Land near Pabda Basti
3.1.11 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
SENES/K-20200/ December 2013 80 ONGC EIA Studies for Exploratory drilling at Pre-NELP Block AA-ONJ/2 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 is given in Table 3.7
TABLE 3-6: SIGNIFICANT EARTHQUAKES IN ASSAM Date of Quake Location of Epicentre Remarks 12 June 1897 Near Rangjoli, Assam Magnitude M 8.0. This was one of the most powerful earthquakes in the 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-50 Indo-China Border Region Magnitude M 8.6. This "Independence Day" earthquake was the 6th largest 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 3.8.
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
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Affected Population Total Damage (in Year Affected Area (lakh ha) (Lakh) Crores INR) All of the 27 districts, 2004 worst affected districts, Karimganj, 122.0 NA Cachar, Nagaon and Golpara
It was revealed from the Flood Hazard Maps (1998-2007) prepared by National Remote Sensing Agency (NRSA) that part of the AA-ONJ/2 Block 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 3.9). Majority of the proposed exploratory wells were not located at the flood prone zones. However, few wells were located at “very low” and “low” probability zones where 10 year flood record (1998-2007) revealed 1-2 times and 3-4 times of occurrence of floods. Well 1, however, is located at the “high” flood zone and experienced flood for 7-8 times in the 10 year flood period. The wells located at different flood prone zones are depicted at the table below and shown at Figure 3.13.
TABLE 3-8: LOCATION OF EXPLORATORY WELLS IN FLOOD PRONE AREA
Sl. No. Name of well River responsible for occurrence of flood 1 RBK-1 Barak River 2 RBK-2 Barak River 3 RLBK-1 Barak River
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FIGURE 3-13: WELLS LOCATED AT THE FLOOD PRONE ZONES
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3.2 BIOLOGICAL ENVIRONMENT
3.2.1 Introduction The AA-ONJ/2 Block is located in Cachar district of Assam; Imphal East District of Manipur and Kolasib & Aizawl district of Mizoram. The area of the Block is approximately 1277 sq. km. The region falls within the Indo-Burma Hotspot as delineated by the International Union for Conservation of Nature & Natural Resources (IUCN) and thereby has been accorded international status in terms of conservation of biodiversity (Refer Box 3.1). It has the richest reservoir of plant diversity in India and is one of the ‘biodiversity hotspot’ of the world supporting about 50% of India’s biodiversity. All types of vegetation like grassland, meadows, marshes, swamps, scrub forest, temperate and alpine are found here. The region exhibits the richest diversity in orchids, zingibers, yams, rhododendrons, bamboos, canes and wild relatives of cultivated plants. It is also considered a cradle of ‘angiosperms’ as primitive plant families such as Magnoliaceae, Lauraceae, Hamamelidacaea, Degeneriaceae, Tetracentraceae and Lardizabalaceae are well represented there. About 50% of the total 17500 flowering plants hail from the region, and 40% of them are endemic. Wild relatives of 132 economically important species, including citrus, banana, rice, sugarcane and pulses originate here.
The primary objectives of the biological environment study are: Assess the vegetation types Identify common flora & fauna in the study area Find out rare and endangered floral and faunal species (if any) Evaluate wildlife habitat of the area and assess impact of the proposed project on wildlife & their habitats. Assess impact of the proposed project on agriculture and domestic livestock.
3.2.2 Methodology
Desktop Review and Reconnaissance Survey
A desktop review (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 on 23rd to 25th 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 on 13th to 17th May 2013 and 30th to 27th May, 2013 for habitat survey,
SENES/K-20200/ December 2013 84 ONGC EIA Studies for Exploratory drilling at Pre-NELP Block AA-ONJ/2 flora & faunal assemblage, in the study area. Baseline survey has two part- (i) Secondary data collection and (ii) Primary Survey.
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; 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 oil & gas drilling activity. Box 3.1: Biodiversity of Indo-Burma Hotspot The proposed oil field falls under Indo- Burma hotspot, which is one of the twenty-five richest biodiversity hotspots of the world. The Indo-Burma hotspot comprises 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 Andman 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. Indo-Burma hosts many endemic primate species, including three species of douc.
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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 (Bunopithecus 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.
3.3 TERRESTRIAL ECOSYSTEM
3.3.1 Forest Resources The AA/ONJ-2 Block (approximately 1277 sq. km) falls under Cachar, Imphal East, Kolasib and Aizawl district. Cachar district has 2236 sq. km under the forest cover, i.e. 59.06 percent of its total geographical area (Source: State of Forest Report 2011, FSI). The forest cover of the district comprises of 81 sq. km (3.6%) very dense forest, 975 sq. km (43.6%) moderately dense forest and 1180 sq. km (52.8%) of open forest. Imphal East districts of Manipur have 32.29% (total geographical area) of forest cover. The forest cover of the Imphal East district comprises of 43 sq. km (19.91%) under moderately dense forest and 173 sq. km (80.09%) of open forest (Source: State of Forest Report 2009, FSI). The forest cover of Kolasib district of Manipur has 2785 sq. km, i.e. 87.44% of its total geographical area. The forest cover of the district comprises of 175 sq. km (14.33%) moderately dense forest and 1046 sq. km (85.67%) of open forest (Source: State of Forest Report 2011, FSI). The forest cover of Aizawl district of Manipur has 3265 sq. km, i.e. 91.33% of its total geographical area. The forest cover of the district comprises of 26 sq. km (0.80%) very dense forest 1205 sq. km (36.91%) moderately dense forest and 2034 sq. km (62.30%) of open forest
3.3.2 Forest Land for Proposed Activity The land use Map (Figure 3.11) shows that 76.59% of the block’s land is under forest. However, majority of forest area is located on Mizoram and Manipur portion of the block. ONGC has plan for 9 exploratory drilling in this Block; 4 drill sites are located in the forest land.
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3.3.3 Vegetation Types The major portion of exploratory block has natural forest. The important forest types found in study area (Source: Forest Types of India 1962 by Champion and Seth) are: Moist semi-evergreen forests Moist Mixed Deciduous forests
Topical Semi Evergreen Forests: From the foothills up to an elevation of 900m above MSL, the climax forests is of a semi evergreen type consisting of species like Tetrameles nudiflora, Bombax malaaricum, Ailanthus grandis, Asstonia scholaris, Pterospermum acerifolium, Duabanga sonneratiodes, etc. are found. In the dominant layer, below the emergent layer, trees like Michelia champaca, Mangliatia insignia, Magnolia griffithi, Pterospermum lanceaefolium, Sterculia alata. Sterculia villosa, etc. are common. These forests are found in the western part of Manipur adjoining Cachar. The classification correspond to Champion & Seths “Cachar Tropical Semi- Evergreen” i.e. 2B/C2. Moist Bamboo brakes: Bamboo brakes and bamboo mixed with scrubs of large extent occur in the western, southwestern and north-western parts of the State. Most of the Cachar Tropical semi-evergreen type of forests in the western part of the Manipur and adjacent district of Assam, Cachar has been hacked down for jhum and the trees has given way to a dense growth of Melocana bamboo interspersed with same clump forming bamboos and rare trees here and there. Bamboo also occurs as an understory in tree forests. Bamboo brakes are found in plenty. Principal species of Bamboos are Dendrocalamus hamiltonii (Kako) and Bambusa tulda (Jati). However, other bamboo species are also found. Cane brakes: In places where the soil is wet over a long period and is in ill drained clay, rich in humus, various species of canes are found. They form an impenetrable thorny thicket sometimes with a few trees standing over them. Vegetations are also recorded in the non-forest are of the block. Tree species in these sites are mostly planted and few are natural. The village woodlot, road side plantation and riparian vegetation are recorded in the study area, these are as follows: 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 Vitex neuganda, etc. 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. Riparian Vegetation: Vegetation along river bank, major plant species are Anthocephalus sinensis, Alistonia scholaris, Bombax ceiba, Terminalia arjuna, etc.
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3.3.4 Floral Diversity Important flora in the block is Michelia champaca, Toona ciliate, Schima wallichii, Gmelina arborea, Messua ferrea, Artocarpus hirsute, Mangifera indica, Castanopsis hystrix, Bombax ceiba, Cinnamomum zeylanicum, Emblica officinalis, Duabanga sps., Melia azedirach, Bauhinia variegate, Phoebe hainesiana, Eugenia praecox, Quercus sps., Albizia procera, Alnus nepalensis, Juglans regia, Terminalia myriocarpa etc. Orchids: Are epiphytic, lithophytic and terrestrial in nature. The Dendrobium, Vanda, Cymbidium, Cattleya and Lycaste are found in abundance. The Phius tunkervels, a rare terrestrial orchid is found in the Barak valley. Thunia alba, which is known as bamboo orchid, is found around Taobam village. Paphiopedilum is found in Leimatak area. Bamboo: There are many species of bamboo grown in this region Assam, Manipur and Mizoram such as Longa, Utang, Khokwa, Saneibi, Maribob, Laiwa, Liwa, Watangkhoi, Nat, Unap, Vee, Wamu, Tenwa, Wak, Oonal, Mobiwa etc During the terrestrial plant survey, about 259 numbers of plant species was recorded, which includes 141 species of trees, 5 species of bamboos, 3 species of canes, 28 species of shrubs, 48 species of herbs, 13 species of climbers, 13 species of grasses & reeds, 8 species of epiphytes. The detailed listing of floral species recorded in the study area is given in Annexure 3.6.
3.3.5 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.
3.3.6 Wildlife Habitat
A habitat survey was carried out both in the AA/ONJ-2 Block and its immediate vicinity. This region is home to a number of charismatic mammalian fauna Tiger, Pygmy hog, Hispid hare, Golden langur, Leopard, Golden Cat, Clouded leopard, Himalaya palm civet, Binturong, Himalayan black bear, Sloth bear, Hollock Gibbon, Sambar, Hog deer, Barking deer, Swamp deer, etc. Wildlife in Assam is given protection through a network of five National Park, 20 Wildlife Sanctuaries, three Tiger Reserves and five Elephant Reserves. Wildlife in Manipur is given protection through a network of two National Park (one declared and one proposed), five Wildlife Sanctuaries (one declared and 4 proposed). Wildlife in Manipur is given protection through a network of two National Park, six Wildlife Sanctuaries (one declared and 4 proposed)
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The Cachar district has a declared wildlife sanctuary (WLS), i.e. Borail WLS on the northern part of the district. East Imphal district has demarcated or proposed WLS. Dampa Wildlife Sanctuary is located in the Mamit district western part of the Kolasib district located at greater than 50km from block boundary. The AA/ONJ-2 Block not falls within these Wildlife Sanctuaries and also no ecological sensitive are located within 10km of the Block boundary (Figure – 3.14). The AA/ONJ-2 Block falls in Lower Jiri Reserve Forest (R.F.), Barak R.F. and Innerline R.F. The Innerline Reserve Forest (RF) is the largest RF in Assam, with an area of more than 110,000 ha. Katakhal and Barak RFs are contiguous with Innerline. The area has a rich diversity of mammals and birds (Choudhury 1983). Innerline, Katakhal and Barak R.F Important Bird Areas (IBA) This site covers parts of Cachar and Hailakandi districts in southern Assam, bordering Mizoram and Manipur. The area is mainly composed of low hills that are the northern promontories of the Lushai or Mizo Hills. Small patches of plain area found between the hills are mostly under human habitation. Dhaleswari, Barak and Sonai are the main rivers. The forests are mainly Tropical Wet Evergreen and Tropical Semi-evergreen. The two characteristic tree species of the area are Dipterocarpus turbinatus and Palaquium polyanthum. There are vast and continuous stretches of bamboo with cane and reeds. About 250 species have been listed, including many endangered ones (A. U. Choudhury pers. comm. 2003). The White-winged Duck is still sporadically recorded (Bird Life International 2001). The Spot- billed Pelican Pelecanus philippensis was also recorded from the fringe of Katakhal RF, but there is no recent report. The Swamp Francolin Francolinus gularis has perhaps vanished from the area due to encroachment on its grassland habitat for cultivation, while the last confirmed record of the Green Peafowl Pavo muticus in Assam was from Barak RF (Choudhury 2000). The major species in this area are Lesser Necklaced Laughingthrush, Blackgorgeted Laughingthrush and Rufous-necked Laughingthrush. During winter, many birds species are migrated into this area. Notable forest birds are Grey-bellied Tesia, Blyth’s Kingfisher, Bluethroated Barbet, Bay Woodpecker, Maroon Oriole, Black-naped Oriole, Grey Treepie, Black-winged Cuckoo Shrike, Short-billed Minivet, White-throated Bulbu, Black Bulbul and Grey Peacock Pheasant , etc. This IBA site has the highest primate diversity in Assam with eight species (Choudhury 1989). They are the Slow Loris, Rhesus Macaque, Pig-tailed Macaque, Stump-tailed Macaque, Assamese Macaque, Capped Langur, Phayre’s Leaf Monkey and Hoolock Gibbon. Other fauna includes Sloth Bear, Malayan Sun Bear, Leopard, Clouded Leopard, Sambar, Hog Deer, Barking Deer, Serow and Gaur. The Gangetic dolphin occurs in Barak River. Turtles recorded include the Keeled Box Turtle and Eastern Hill or Asian Brown Tortoise. Both Indian Rock and Reticulated pythons have been recorded here, besides the King Cobra and other snakes. The site is under heavy biotic pressure, including encroachment, felling of trees, large-scale and unscientific harvesting of bamboo for paper mills. Poaching, often across the Mizoram border, is also a major issue. (Source: Important Birds Area in India- Assam)
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FIGURE 3-14: ECOLOGICAL SENSITIVITY MAP
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Elephant Habitat The Barak valley specially Cachar, Hailakandi and Karimganj area only minor elephant population and splinter sub-populations are recorded. The habitats are known as Barail - Jainta Hill (Assam-Meghalaya), Karimganj [Assam and Tripura] and Hailakandi (Assam). The exploratory block (AA/ONJ-2) is not fall in these elephant habitat.
Primate Habitat Primate Habitat in Cachar: The Innerline, Katakhal and Barak R.F IBA is the highest primate diversity in Assam with eight species (Choudhury 1989). The Hoolock gibbon, occurs in some reserve forests of Cachar district of Barak Valley, Assam; but its numbers is declining due to habitat loss and hunting. They are now surviving in some isolated pockets in the reserved forest areas. A status survey was done in the Inner line reserved forest and its adjoining areas from July 2010 to Dec. 2011. Ten family groups and thirty-three individuals made up the total count. (Source: Preliminary study on Population status and Activity budgeting of Western Hoolock Gibbon (Hoolock hoolock) in the Inner-line Reserved Forest of Barak valley, Assam, India. Mofidul Islam, Parthankar Choudhury, P. C. Bhattacharjee). Hoolock Gibbons Habita in Manipur: Hoolock Gibbons are confined to six districts-Chandel, Churachandpur, Senapati, Tamenglong, Ukhrul and Imphal East of Manipur. The Hoolock Gibbon habitat in Imphal East is recorded in eastern part of district towards, Tamenglong district; the AA/ONJ-2 block is located in western part of district. Hoolock Gibbon habitat is shown in Figure 3.15. Hoolock gibbons occur in all the districts, namely Aizawl, Champhai, Kolasib, Lawngtlai, Lunglei, Mamit, Saiha, and Serchhip. The main populations, however, survive in Champhai, Lawngtlai, Lunglei, Mamit, and Saiha districts. Protected areas where they have been recorded include the wildlife sanctuaries of Dampa, Khawnglung, Lengteng, and Ngengpui, and the Murlen and Phawngpui (Blue Mountains) national parks. The Hollock Gibbon distribution map shows that exploratory block is falls in the thinly distributed primates habitat (Source: The Distribution and Status of Hoolock Gibbon, Hoolock hoolock, in Manipur, Meghalaya, Mizoram, and Nagaland in Northeast India; Anwaruddin Choudhury, Primate Conservation 2006 (20): 79–87).
Carnivores Sloth Bear, Malayan Sun Bear, Leopard, Clouded Leopard are reported in the Innerline R.F. The lesser carnivores like, jungle cat (Felis chaus) the large Indian civet (Viverra zibetha), the small Indian civet (Viverricula indica), the Indian fox (Vulpes bengalensis), the common mongoose (Herpestes edwardsi), the small Indian mongoose (Herpestes auropunctatus) etc. was reported in the secondary sources.
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FIGURE 3-15: HOOLOCK GIBBON HABITAT IN THE STATE OF MANIPUR & MIZORAM
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3.3.7 Faunal Diversity Mammals: Mammals within the study area are represented by 29 species of large and smaller mammals. The checklist of mammals in the study area is given in Annexure 3.7. There is no record of large herbivores and carnivores in the study area. Among mammalian species, Hollock gibbon, Langures, Spotted linsang, Bear, Barking Deer, Sambar, Leopard, Jackal Pangolin, Wild Boar, Jungle Cat, Indian Civet Cat, Fishing Cat, Clouded Leopard, Slow Loris, Hog badger are reported in the exploratory block Avifauna: Avifauna in the study area are represented by Grey-bellied Tesia, Blyth’s Kingfisher, Bluethroated Barbet, Bay Woodpecke, Maroon Oriole, Black-naped Oriole, Grey Treepie, Black-winged Cuckoo Shrike, Short-billed Minivet, White-throated Bulbu, Black Bulbul and Grey Peacock Pheasant, Lesser Adjutant Stork, White Winged Wood duck, White cheeked Hill Partridge, Black-browed Leaf Wabler, Green Imperial Pigeon, Purple wood or Pale capped Pigeon etc. A total of 89 species of avi- fauna were recorded from the forest area. The detailed checklist of avi-fauna in has been presented in Annexure 3.8. Reptilian Species: Reptilian fauna in the study area represents by the King cobra, skink, lizard, gecko etc. A total of 25 reptilian species were recorded from the study area. The detailed checklist of reptilian species has been presented in Annexure 3.9.
3.3.8 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 II of the Indian Wildlife (Protection) Act, 1972 and amendment in 1991. About 10 species of Schedule I species were recorded from the study area. (Refer Table 3.10).
Table 3-9: SCHEDULED ANIMAL SPECIES IN THE STUDY AREA Wildlife Schedule Sl. No. Scientific Name Common Name A. Schedule I A.1 : Mammals A.1.1 Felis bengalensis Leopard Cat A.1.2 Felis marmorata Marbled Cat A.1.3 Felis temmincki Golden Cat A.1.4 Helarctos malayanus Sun Bear A.1.5 Manis pentadactyla aurita Chinese Pangolin A.1.6 Nycticebus coucang Slow Loris A.1.7 Panthera pardus Leopard A.1.8 Prebystis pileatus Capped Langur A.2 Birds A.2.1 Anthracocerus albirustris Indian pied hornbill A.2.2 Bucerus bicornis Great pied hornbill
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3.4 AQUATIC ECOSYSTEM
3.4.1 Aquatic Habitat The Oil Block is falls under Barak River basin. The major rivers in the block are Barak, Sonai, Jiri, Chiri and Rukni. There are also numbers of seasonal rivers and nalas in the Oil Block. All these rivers and nalas form the aquatic ecosystem. Riparian vegetation was also recorded from the banks of these rivers. Following aquatic ecological groups has been studied.
3.4.2 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 29 species of aquatic macrophytes were recorded from these aquatic ecosystems (Annexure 3.10).
3.4.3 Fishes & Fisheries Fish is widely available in the still (Bills / Ponds) and flowing water bodies (Rivers/Nalas) of the Cachar region. Freshwater fish species in the wetlands of Assam has been well represented. Major fish fauna of fresh water bodies include catla, rohu, mrigala, bata, punti, titpunti, maurala, chela, boal, lata, shole, kholse, pancal, baan, tangra, etc. A total of 35 species of fishes were recorded from these aquatic ecosystems. (Annexure 3.11).
3.4.4 Amphibia Of the 206 amphibians species known from India, only 7 species were recorded from this area during the study period.
3.4.5 Aquatic Birds The survey results show 18 species of aquatic birds in the study area (Annexure 3.12). Aquatic Mammals: The survey results show one species of aquatic mammal, common otter (Lutra lutra) from the study area.
3.4.6 Endemic, Threatened & Endangered Species The wetland areas are the habitat of some endangered and threatened species which are listed in the Schedule I and II of the Indian Wildlife (Protection) Act. No Schedule I faunal species was recorded in the Aquatic ecosystem in the study area.
3.5 AGRICULTURAL DIVERSITY The Cachar district is falls under Barak valley zones where the climate is subtropical, warm & humid, annual rainfall is approximately 1990 mm. The major cropping systems of this district are rice based cropping system, Plantation based cropping system, Horticultural crop based cropping system and forest. Rice is grown mainly as mono crop or double crop, rice in
SENES/K-20200/ December 2013 94 ONGC EIA Studies for Exploratory drilling at Pre-NELP Block AA-ONJ/2 sequence with vegetable / oilseed. There are systems of intercropping like areca nut, banana, pineapple, potato, French bean etc. The district is suitable for growing fruits like coconut, areca nut, banana, pineapple, jackfruits, guava and citrus. Rest type of vegetables like Cole crops , brinjal, tomato, french bean, country bean , cowpea are extensively grown in the district. Among the spices Chilly, coriander, ginger, turmeric are grown Most of the cultivable land remains fallow in winter due to lack of irrigation facilities. The consultation with local people revels that the farmers are cultivating the improved varieties in the field, the traditional varieties has not been cultivated in the recent times. Combining jhum and permanent cultivation is major cultivation in Manipur and Mizoram. Paddy is the main crop of the district. Other important crops are maize, wheat, pulses and oil seeds The proposed drilling site is a mono-crop agriculture land; only paddy is cultivated during the monsoon. As this is comparatively an upland, mainly HYVs were cultivated during the recent period.
3.6 LIVESTOCK Livestock like cattle, buffalo, goat sheep, duck, and pig are reared for dairy products, meat, egg and for agriculture purpose. Majority of cattle and buffalo are local variety. Backyard poultry farms are mostly common in this area; however, some commercial poultry farms are also recorded in the district. Livestock use agriculture field during the off-season as a seasonal grazing field, and their source of drinking water is surface water (ponds and stream). As the proposed drilling site is mono-crop area and there is no water body, therefore due to the proposed project there will be no direct impact on domesticated animals. But due to discharge of waste water from the drilling activity the nearby surface water (stream) may be chemically polluted and affect one of the drinking water resources for domesticated animals
3.7 SOCIOECONOMIC ENVIRONMENT This section discusses the baseline socio-economic environment of the AA-ONJ/2 Block in the Cachar district of Assam, Kolasib district of Mizoram and Imphal East district of Manipur with respect to ONGC’s proposed exploratory 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 exploratory block. As the study area defined for the proposed project encompasses three districts (Cachar, Kolasib
SENES/K-20200/ December 2013 95 ONGC EIA Studies for Exploratory drilling at Pre-NELP Block AA-ONJ/2 and Imphal East) the profiling of the project socioeconomic environment has focused primarily on the villages located in the aforesaid districts.
3.7.1 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. an understanding of the needs, demands, preferences, capacities and constraints of the people in the The assessment facilitated 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 prioritise ONGC’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.
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 Panchayet 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 ONGC personnel and members of the local community. The local communities which would primarily be affected were identified based on the location of the tentative exploratory and drilling operations as proposed by ONGC. 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.
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Consultations
Consultations with key stakeholders are a continuous process that was carried all through the EIA process. 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 ONGC’s CSR activity.
3.7.2 General Socioeconomic Profile The AA-ONJ/2 Block falls under the Cachar district of Assam, Kolasib and Aizawl district of Mizoram and Churachandpur and Imphal East district of Manipur. The block is primarily located in Cachar district of Assam. The general socio economic profile of these three state along with its districts coming under this block is described below: 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 2001-11. 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 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)3. According to a study by Nath, 20124, there has been undocumented migration in Assam especially in the districts bordering Bangladesh. The study shows that the growth has been
3 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
4 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.
SENES/K-20200/ December 2013 97 ONGC EIA Studies for Exploratory drilling at Pre-NELP Block AA-ONJ/2 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 Cachar district of Assam comprises of 2 administrative sub divisions. The administrative divisions are further subdivided into 5 nos. revenue circles. The geographical area of Cachar district is 3786 sq. km. The total population of the district as per 2001 census is 1444921 which has increased to 1736319 (as per provisional figures of Census 2011) indicating a decadal growth of 20.17%. The sex ratio has improved from 945 (Census 2001) to 959 (provisional figures 2011) while the population density has increased to 458 from 382. The literacy rate of the district was 67.82% in 2001 which has increased to 80.35% in 2011 (Male: 85.85% and Female: 74.62%). In fact the literacy rate of the female population has increased at a rate higher (which was 59.41% previously) than that of the male population (which was 75.28% previously). Total population of Manipur as per 2011 census is 2,570,390 of which male and female are 1,290,171 and 1,280,219 respectively. In 2001, total population was 2,293,896 in which males were 1,161,952 while females were 1,131,944. The total population growth in this decade was 12.05 percent while in previous decade it was 30.02 percent. The population of Manipur forms 0.21 percent of India in 2011. Population density of Manipur is 115 per sq km which is lower than national average 382 per sq km. Sex Ratio in Manipur is 992 i.e. for each 1000 male, which is above national average of 940 as per census 2011. Literacy rate in Manipur has seen upward trend and is 79.21 percent as per 2011 population census. Of that, male literacy stands at 86.06 percent while female literacy is at 71.73 percent. In 2001, literacy rate in Manipur stood at 70.53 percent of which male and female were 80.33 percent and 61.46 percent literate respectively. Imphal East has 4 sub division, 9 revenue circle, 26 gram panchyet, According to the 2011 census Imphal East district has a population of 452,661. The district has a population density of 638 / square kilometer. Its population growth rate over the decade 2001-2011 was 14.63%. Imphal East has a sex ratio of 1011 females for every 1000 males, and a literacy rate of 82.81%. Total area of Mizoram is 21,081 sq. km. Population of Mizoram as per 2011 census is 1,097,206 of which male and female are 555,339 and 541,867 respectively. In 2001, total population was 888,573 in which males were 459,109 while females were 429,464. The total population growth in this decade was 23.48 percent while in previous decade it was 29.18 percent. The population of Mizoram forms 0.09 percent of India in 2011. Density of Mizoram is 52 per sq km in 2011 which increased from 42 per sq km in 2001, but still lower than national average 382 per sq km. Sex Ratio in Mizoram is 976 i.e. for each 1000 male, which
SENES/K-20200/ December 2013 98 ONGC EIA Studies for Exploratory drilling at Pre-NELP Block AA-ONJ/2 is below national average of 940 as per census 2011. In 2001, the sex ratio of female was 938 per 1000 males in Mizoram. In 2001, literacy rate in Mizoram stood at 88.80 percent of which male and female were 92.53 percent and 86.75 percent literate respectively, which increased to 91.33 percent as per 2011 population census. Of that, male literacy stands at 93.35 percent while female literacy is at 86.72 percent. Kolasib district is divided into three subdivisions. According to the 2011 census Kolasib district has a population of 83,054. The district has a population density of 61/square kilometer. Its population growth rate over the decade 2001-2011 was 27.28%. Kolasib has a sex ratio of 956 females for every 1000 males, and a literacy rate of 93.50%. According to the 2011 census Aizawl district has a population of 404,054. The district has a population density of 113 inhabitants per square kilometer (290 /sq mi). Its population growth rate over the decade 2001-2011 was 24.07% Aizawl has a sex ratio of 1009 females for every 1000 males, and a literacy rate of 98.5%.
3.7.3 Demographic Profile The study area for socio economic profiling was defined within block and surrounding areas based on the proposed location of exploratory and its proximity to the village and professional judgment. Of the study area defined, the baseline study focuses on forty two villages within the block. This comprises of thirty two villages of Cachar district, seven villages of Imphal East district, one village in Aizawl district and two villages in Kolasib district. The list of village identified for baseline profiling along with its proximity to well location has been described in Table 3.11 below:
TABLE 3-10: LIST OF THE STUDY AREA VILLAGES IN THE AA-ONJ/2 BLOCK
Proximity to Villages District Sub-District Well RBK-1 Tulagram Pt-II, Tundurkandi, Cachar Sonai Majhirgram, Kajidahar Pt I, Tulargram Pt I, Dungripar Pt I, Satkarakandi Pt II, Dhanehari Pt II, Dhanehari Pt II RBK-2 Niz Rupai Bali, Kaptanpur Pt I, Cachar Sonai Singerbond Pt IV, Kaptanpur Pt XVII, Kaptanpur Pt XV, Kaptanpur Pt XVIII. RPAA Nayagram, Digor Fulertol Pt I, Digor Cachar Lakhipur Fulertol Pt II, Digor Fulertol Pt III, Fulertol, Binnakandi Pt I RBK-3 Machkhal Pt III, Robipur Grant, Cachar Lakhipur RLBK-1 Tilka Grant, Binnakandi Grant Cachar Lakhipur RTDN-1 Bishnupur, Jamalpur, Bidyaratanpur, Cachar Sonai Narayanpur, Garultolaekth F.V., Rajnagar, Anandakhal.
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Proximity to Villages District Sub-District Well RJDR Latingkhal, Baiboni, Ahamadabad, Imphal East Berabak, Nungphou, Makhabosti, (Jiribam) Jiribam Chandranathpur RTNG-1 Kani Aizawl Darlawn RTDN-2 Saiphai Basti, Saipum Basti Kolasib North Thingdawl
The study area for socio economic assessment was defined as an area within 1-2 km radius around the 9 exploratory 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 3.13. However, the village level demography, literacy, work class and socioeconomic data of the 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 Binnakandi Grant (4898) is having the highest population among the study area villages followed by Singerbond Pt IV. (3766) and Dhanehari Pt II (3401). The lowest populations were recorded for Robipur Grant (29) village. All the above-mentioned villages belonged to the Cachar district. The household size of the study area villages generally ranged within 4.29 to 6.38 with an average household size of 5.36.
Sex Ratio The average sex ratio of 950 recorded for the study area villages.The highest sex ratio is recorded for Kaptanpur Pt XVII (1169) followed by Kaptanpur Pt I (1084) village. Of all the villages within the study area, 85.7% of the villages have a sex-ratio of more than 900 and the lowest sex-ratio was been recorded at Robipur Grant (450). Scheduled Caste (SC) & Scheduled Tribes (ST)
The overall demographic data of study area villages shows only 14.75% of the population to be under SC category whereas 5.41% population belongs to scheduled tribe category. The highest percentage of schedule tribe population was observed for Saipum Basti in Mizoram (91.52%) whereas the highest population of schedule caste population was observed for Tulagram part II village (56.01%).
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.
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The average literacy rate of the study area villages observed as 44.03% which is well below the state literacy rate (67.20%). The highest literacy rate was observed in Fulertol (95.99%) and the lowest in Machkhal Pt III village (30.86%). Average male and female literacy rate in the study area was recorded at 75.23% and 58.75%. Detailed literacy profile of the study area villages are given in Annexure 3.14.
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. The total working population in the study area villages varies from 23.36% to 92.93%. Of the total workforce, Kani village revealed the highest percentage of workforce with 92.93% workers while Kaptanpur Pt XVII revealed the lowest workforce percentage (23.36%). It has been revealed from the assessment that “other worker “category contributes highest workforce category constituting of 39.07% of the study area population involved in Government and private offices, small business entrepreneurship etc. The next highest working population constituting about 38% is involved in agricultural crop cultivation. The study area mainly comprises of mono-cropped land with paddy being the major agricultural produce. Workforce participation in the study area village is shown in Annexure 3.15.
3.7.4 Socioeconomic Infrastructure
Medical Facilities Twenty two (22) villages out of assessed 42 villages are coming under Sonai block of Cachar district whereas 10 villages are coming under Lakhipur block. Following infrastructure (Table 3.12) in terms of Medical Facilities are observed in Sonai and Lakhipur circle:
TABLE 3-11: MEDICAL INFRASTRUCTURE IN SONAI AND LAKHIPUR BLOCK No of No of No of No of Primary No. of Primary Sl.No Block Allopathic Homeopathic Allopathic Health Centre Health sub Hospital Hospital Dispensary centre Cachar District – Assam 1 Sonai 3 0 2 3 2 2 Lakhipur 12 0 1 9 3 Source: Census Data 2001 Of the study area villages, six (6) villages namely Tulagram Pt I, Bidyaratanpur, Digor Fulertol Pt II, Chandranathpur, Saiphai Basti and Saipum Basti are having medical facility within the village. Of these, one allopathic hospital is present in Bidyaratanpur, whereas allopathic dispensary is present in Tulagram Pt I village. Sixteen (16) villages have allopathic hospital within 5 km of the village. Health centre and Primary health centre is present in
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Digor Fulertol Pt II village. Ten (10) villages are having the facility of Primary Health Centre within 5 km.
Educational Facilities The study area possesses necessary educational infrastructure to cater to the educational needs of the both rural and urban population. Major portion of the block is coming under Sonai and Lakhipur circle of Cachar district. The educational scenario of the said two block are presented in Table 3.13
TABLE 3-12: EDUCATIONAL FACILITIES OF DISTRICTS COMING UNDER AA-ONJ/2 BLOCK
Primary Middle High Higher Secondary Sl.No Block Schools Schools Schools Schools Cachar District – Assam 1 Sonai 429 128 31 5 2 Lakhipur 276 90 21 1 Imphal East District- Manipur 29 8(Govt.+Govt. 8(Govt.+Gov 1(Govt.+Govt. 3 Jiribam (Govt.+Govt. Aided) t. Aided) Aided) Aided) Kolasib District-Mizoram North 42 22 8 0 4 Thingdawl Aizawl District-Mizoram 5 Darlawn 79 46 16 0 Source: Census Data 2001 Among the assessed 42 villages, 39 villages are having educational facilities. Cumulatively, 79 primary schools, 29 middle schools, 6 high schools and 2 higher secondary schools are reported from the study area villages.
Drinking Water facilities The Census data reveals that drinking water facility exits in all the assessed villages. Tubewell is present in all of the villages, whereas wells are present in 26% of the study villages. On the other hand, 28% villages are having tubewell whereas 30% villages are having the provision of handpump as a source of drinking water. Transport & Communication Manipur Road (NH-53) and Mizoram Road (NH-54), Sonai road, Kabuganj Road, Sher Khan –Bhaga Ropad, NEEPCO-Tuirial Road are the major road of transportation of local people. Communication facilities in terms of Bus Service are present in 19 villages out of 42 assessed villages.
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Power Supply Electricity is available in majority of the study area villages through a stable 220V electricity supply adequate for domestic 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 stakeholder consultations and group discussions with village people which was undertaken during the block site reconnaissance visit. The summary findings of the consultations carried out have been discussed below: Majority of the people in the area are either working with Government or Private Offices or runs a small business. Apart from these, paddy cultivation is the major livelihood of the people. Majority of the houses in the rural and urban areas have electrical connections for domestic use. However frequent power failures were reported by the locals during the consultation. Water requirement is catered through household tube well/hand pump in the village areas. Almost every village has a primary school; however, percentage of students pursuing higher education is comparatively less. The medical facilities in the area are also not satisfactory. During the public consultations the household members expressed their concern about the health facilities. Proceedings of public consultation carried out in the block are given in Annexure 3.16.
3.8 CULTURAL AND HISTORICAL SITES Cachari ruins consisting of small unfinished dwelling house, Baradwari, East wall, Singh Darwaza Temple of Ranahandi and Shan mandir is present in Khaspur location at a distance of 14km from the block boundary. Apart from this, some of the village in the block 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.
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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 exploratory drilling operations.
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 exploratory well 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 (Medium) 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 exploratory block Largely local level impact limited to immediate vicinity of the 2 exploratory well site Impact not discernable on a local scale 1
Duration The impact is likely to occur during the entire project life cycle at all 3 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
SENES/K-20200/ December 2013 105 ONGC EIA Studies for Exploratory drilling at Pre-NELP Block AA-ONJ/2 account, wherever appropriate in the criterion sets, to aid in ONGC’s effort to comply with all relevant legislation and project HSE requirements. Additionally, the results of quantitative impact prediction exercise, wherever undertaken, have also been fed into the process.
TABLE 4-2: CRITERIA BASED SIGNIFICANCE OF IMPACTS
Severity of Impact Extent of Impact Duration of Impact Impact Significance (A) (B) (I) (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 is 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
e
angered angered
uals
lation
Activity
Aesthetics &Vis Aesthetics AirQuality NoiseQuality & Traffic Transport Use Land SoilQuality Habitat & Flora Floral Habitat Wildlife Fauna &End Threatened species &rout 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 Popu 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 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
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 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. Exploratory Well 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 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 Site Restoration x x +
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4.2 IMPACT ASSESSMENT This section discusses the impacts of the project activities during exploratory drilling operations 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 exploratory well 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 Visual impacts during proposed drilling operations is anticipated from site clearance and top soil removal, well site and access road construction, vehicles involved in transportation of raw materials and personnel, generation of municipal waste during construction and operational phases, material stockpile, physical presence and operation of drilling rig and associated facilities. During drill site preparation nearly 2.25 ha land is to be cleared for construction of drill site. Vegetation clearance will be required for construction of approach road for the wells namely RPAA, RBK-3, RTNG-1 and RTDN-2. Therefore, tree felling would be required during site preparatory activities and the site cannot be restored back to its original condition from this point of view. Considering the following aspect, the impact is anticipated to be of Medium significance. 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 major. Visual impact due to the operation of drilling rig and presence of base camp is not considered significance given the temporary nature of exploratory activities (about 60 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 . However such activity is likely to be of intermittent in nature and to occur only during process upset and production testing. Reinstatement of well site not indicative of any commercially exploitable hydrocarbon reserve is also likely to positively contribute to the site visual aesthetic. Severity of Impact 2 Extent of Impact 2 Duration of Impact 2 Impact Significance = 8 i.e. Medium
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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; Construction wastes and municipal solid waste temporarily stored at the sites will be transported to the designated disposal site/facility at regular intervals; After decommissioning of rig and associated facilities, drill sites will be restored – drill platform will be removed, pits & garland drains will be filled up, construction materials will be removed & disposed; 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 PM, NO2, SO2 etc.) in the ambient air near well site facilities. However considering localized nature of impacts, temporary nature of construction and drilling activities along with necessary mitigation measures is likely to be adopted by the proponent and 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, aggregates and borrow material will be required at each well site location for road construction/strengthening and site preparatory activities. Approach roads are required to be constructed or strengthened or widened for all proposed exploratory wells. Fugitive emission is therefore anticipated from transportation, storage and handling of construction materials. However, generation of such fugitive dust is likely to be governed by micro-meteorological conditions (wind speed and direction) and the transportation route considering the exploratory drilling activity will be carried out during dry season and majority of internal roads are kutcha or in degraded condition. It has been observed during baseline profiling of ambient air quality that concentration of particulate matter is well within the National Ambient Air Quality Standard. However, the construction activity, rig mobilization and decommissioning activity is temporary in nature and involves limited movement of project vehicles. Therefore, no significant impact is envisaged if specific mitigation measures are adopted. Severity of Impact 2 Extent of Impact 2 Duration of Impact 2 Impact Significance = 8 i.e. Medium
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Air pollution related impacts on flora and fauna, human communities residing close to the proposed drill sites have been described at sections 4.2.10 and 4.2.11 respectively. Occupational health related impacts to workers exposed to high levels of air pollutants have been described in Section 4.2.12. The detail plan for controlling impacts related to air quality due to proposed exploratory drilling activities have been provided in Chapter 6.
Operation of Diesel Generator (DG) Sets The proposed project will involve the operation of four diesel driven 750 KW generators for drilling of each exploratory well. The operation of DG sets will therefore 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 site only under exceptional combination of meteorological conditions. However, considering the temporary nature of drilling phase (approx 60 days), wet and humid conditions prevalent in the exploratory block 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 section 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 ISC-ST 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) (m/s) PM NO2 SOx 750 KW DG 9 0.30 773 17.0 0.008 1.3 0.03
Though, ISC3 is a refined model, the model run was carried out based on micro- meteorology to predict air quality impacts for a average 24 hr period that may be caused by peak power utilization at the drill site. The model was run considering operation of two 750 KW DG set. To predict the incremental concentrations of the pollutants due to the proposed project activities the concentration values for these pollutants estimated during the baseline monitoring was also taken into account (Refer Table 4.5).
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TABLE 4-5: PREDICTED GLCS FOR AIR POLLUTANTS Pollutants Predicted GLC at Hmarkhawlien (μg/m3) Predicted Maximum GLC (μg/m3) Baseline Distance Incremental Predicted Incremental at from Direction Concentration GLC Concentration Hmarkhawlien Well (m) 750 KW DG Set NO 2 0.17950 19.6 19.7795 49.84079 2687 NNW μg/m3) PM 0.00108 62 62.00108 0.30369 2687 NNW (μg/m3) HC 0.00028 776.6 776.60028 0.07668 2687 NNW (μg/m3) SO 2 0.00414 5.1 5.10414 1.15017 2687 NNW (μg/m3)
For spatial mapping of pollutants, the GLCs revealing worst case scenarios were superimposed on land use (5km x 5 km area) abutting RPAA. The baseline air pollutant concentration of Air Quality monitoring station at Hmarkhawlien was considered while determining predicted GLCs. The incremental Ground Level Concentration (GLCs) of the pollutants (as discussed above), do not exhibit any deterioration in air quality. The impact on ambient air quality is not predicted to have significant change 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. As the proposed drilling is exploratory in nature, therefore only chances of flaring will generate from well testing and therefore the impacts anticipated to be low. Severity of Impact 2 Extent of Impact 2 Duration of Impact 1 Impact Significance = 4 i.e. Low
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FIGURE 4-1: PREDICTED NO2 CONCENTRATION PLOT (2 X 750 KW DG SET)
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FIGURE 4-2: PREDICTED PM CONCENTRATION PLOT (2 X 750 KW DG SET)
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FIGURE 4-3: PREDICTED SO2 CONCENTRATION PLOT (3 X 750KW DG SET)
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FIGURE 4-4: PREDICTED HC CONCENTRATION PLOT (3 X 750 KW DG SET)
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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 access 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. 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 of appropriate stack height will be utilized. Providing Personnel Protective Equipments (PPEs) like mask to workers at site.
4.2.3 Impact on Noise Quality Potential impact on noise quality is anticipated from operation of construction machineries/equipments, operation of drilling rig, vehicular movement during site preparatory activities and from operation of diesel generator set. Operation of construction machinery/equipments Operation of heavy machinery/equipments and vehicular movement during site preparatory activities and road strengthening may result in the generation of increased noise levels as specified in the 2.7.6. The same can be used as a reference for calculating probable noise pressure levels arising out of a number of such equipments. 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 very close to the proposed well site and site access road. Distance of settlements varies from 100m to 1.5 km from the proposed exploratory drilling locations. Considering the construction phase activities to be of temporary nature, limited daily movement of project vehicles (3-4 nos. vehicles for transportation of personnel and 8-10 nos. for material transport) and adequate mitigation measures viz. equipment maintenance etc. to be implemented by the project proponent, impact is not considered as significant.
Severity of Impact 1 Extent of Impact 2 Duration of Impact 2 Impact Significance = 4 i.e. Low
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
SENES/K-20200/ December 2013 116 ONGC EIA Studies for Exploratory drilling at Pre-NELP Block AA-ONJ/2 contributors of high noise level at the developmental 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 2.6 for reference. 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 50 m) of the rig facility. Occupational health and safety impacts viz. Noise Induced Hearing Loss (NIHL) is also anticipated on personnel working close to such noise generating equipment. However, considering short duration of drilling period (approx 45-60 days) and necessary noise prevention and control measures viz. use of acoustic barriers, provisions for proper PPEs, regular preventive maintenance of equipments etc. to be implemented by the-proponent no significant impact to this regard is envisaged.
Noise related impacts on flora and fauna, human communities residing close to the proposed drill sites have been described at sections 4.2.10 and 4.2.11 respectively. Occupational health related impacts to workers exposed to high noise levels have been described at Section 4.2.12. Noise Level Prediction A noise modeling exercise has been undertaken based on standard noise attenuation equations to predict noise levels from drilling rig near sensitive receptors. A noise attenuation plot has been developed considering natural attenuation by distance with noise level predictions only expected to help in planning and decision making. The cumulative noise generated from rig, mud pump, DG and shale Shaker was calculated to be 95.0 dB(A). 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 69.0 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) leading to discomfort to neighbouring communities. However, with the introduction of a noise barrier at the fence-line with a height of 4 m the noise level may be controlled. This control measure will be enough to decrease noise levels near sensitive receptors at 200m to about 55.98 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 4.6 below. Formula used for calculation of noise level is given in Annexure 4.1.
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FIGURE 4-5: NOISE ATTENUATION PLOT
Severity of Impact 2 Extent of Impact 2 Duration of Impact 2 Impact Significance = 8 i.e. Medium
Mitigation measures for controlling impacts on noise quality Typical mitigation measures for noise will include the following: 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 to less sensitive areas to take advantage of distance and shielding Providing Personnel Protective Equipments (PPEs) like ear plugs/muffs to workers at site. Undertaking preventive maintenance of vehicles and machinery to reduce noise levels. The detailed plans to control impacts on noise quality due to the proposed developmental drilling activities have been provided at Chapter 6.
4.2.4 Potential Impact Transport and Traffic The impact of transport and traffic could be anticipated from movement of trucks, trailers and private vehicles. The drill site approach roads (i.e. Village road, tea garden roads) are not busy vehicular route. Additionally approach road to most of the exploratory well sites are
SENES/K-20200/ December 2013 118 ONGC EIA Studies for Exploratory drilling at Pre-NELP Block AA-ONJ/2 kucha in nature and movement of vehicle will have a definite effect on the integrity of the road. 60 trailer/truck load material will be transported during site construction and decommissioning phase from Srikona to each drill sites (as discussed in Section 2.6.1). Therefore, movement of heavy vehicles will have a definite effect on integrity of the road. Increased traffic load can also pose disturbance to the settlement in terms of increased noise level and can arise safety related issues. In the transport route, there are number of schools viz. AG English ME School, Sibananda Buniyadi Vidyalaya, Tilka Primary School, Mejhirgram LP School. Disturbance to traffic movement during school time is therefore anticipated from additional traffic during school hour. However, as all the approach roads will be strengthened and mitigative measures to be adopted to curb the anticipated impact generated from noise from traffic, it 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 Land use related impacts for the proposed project is anticipated from temporary diversion of agricultural and forest land for construction of exploratory well sites and associated approach road (as discussed in Section 2.6.1). However, such land use changes is likely to be temporary in nature considering the duration of exploratory drilling period to be about 60 days. Further, given the limited land requirement for each drill site (2.25ha), no major change in land use is anticipated from the proposed project ONGC will conduct site restoration and will hand over the land either to the land owner or to the Forest Department, provided that there is no potential hydrocarbon reserve on the site. Severity of Impact 1 Extent of Impact 2 Duration of Impact 2 Impact Significance = 4 i.e. Low
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 from site clearance and top soil stripping for exploratory 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 during baseline profiling of Soil Quality in Section 3.1.10, the soil of exploratory block coming into the Assam province is silty alluvial in nature thereby contributing to the agricultural productivity of the region. On the other hand soils are rich in humus in Mizoram province of the block. Stripping of top soil is therefore likely to affect the soil fertility of the well site. 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
SENES/K-20200/ December 2013 119 ONGC EIA Studies for Exploratory drilling at Pre-NELP Block AA-ONJ/2 the exploratory wells are not indicative of any commercially exploitable hydrocarbon reserves. Necessary surface run-off control measures need to 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. Further necessary mitigation measures will be implemented by the proponent with respect to the borrow area reinstatement (particularly those located on agricultural land) and run-off control to prevent any possible impact on soil quality. 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 250-300 m of drill cuttings and 700m of drilling mud is likely to be generated from each well during exploratory 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 a HDPE lined impervious pits of capacity ~500 m3 each for temporary storage of drill cuttings and 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 and is not anticipated to pose any potential threat to the soil environment. The impact is therefore considered to be of low significance. Severity of Impact 1 Extent of Impact 2 Duration of Impact 2 Impact Significance = 4 i.e. Low
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Storage and handling of fuel and chemicals As discussed in Section 2.6.2 during the process description of exploratory well drilling, it is anticipated that 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 also 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 by the proponent the impact is not considered to be of significance.
Severity of Impact 2 Extent of Impact 1 Duration of Impact 2 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 and chemicals to prevent any potential contamination from spillage. Implementing appropriate spill prevention and control measures.
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, surface runoff from construction sites and restoration of exploratory 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 raising of acquired/leased land to about 0.25 m from the ground level it may lead to alteration of onsite micro-drainage pattern leading to potential problems of water logging in the agricultural land and settlements abutting the drill site. This problem is likely to be further aggravated due to heavy rainfall experienced by Cachar district throughout the year. The approach roads in major portion of the block are characterized by unpaved rural roads which are adversely affected during intense rainfall received by the district. Effect of rainfall on unpaved rural roads is more pronounced as this could lead to complete isolation of few
SENES/K-20200/ December 2013 121 ONGC EIA Studies for Exploratory drilling at Pre-NELP Block AA-ONJ/2 villages from the other parts of the district. Well specific environmental setting study shows that excepting RBK-3 and RTDN-1, wells located in Assam province of the block are close to existing road. Stretch of site approach to be constructed for drill site in these wells varies from 0 to 100m only. Additionally, widening/ new construction of roads as required in RBK- 2, RBK-3, RTDN-1, RJDR and RTDN-2 could result in the alteration of drainage along water crossings and may lead to water-logging of adjacent lands and settlements, if not properly managed. It has been observed that in case of RTDN-1, a local drainage channel namely Udkhal is passing along the village and caters the household requirements. Therefore cross drainage structure an i.e. culvert is to be prepared in order to keep its uninterrupted flow. Therefore, considering the provision of cross drainage structures at road embankments and stream crossings by the proponent to ensure uninterrupted drainage flow, 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
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 neighboring agricultural land abutting the site. However, adequate care will be taken by the project 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 consumption of water for construction and domestic use for Laborers,
SENES/K-20200/ December 2013 122 ONGC EIA Studies for Exploratory drilling at Pre-NELP Block AA-ONJ/2 discharge of contaminated surface run-off, sewage and process waste water generated during various phases of the proposed project.
Surface run-off discharge 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 on open soil is likely to be contaminated leading 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 Cachar district. However, taking into account the provision of onsite drainage system and sediment control measures to be implemented by the proponent 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 700 m3 of drilling waste and process waste water 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 and subsequent treatment 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 not considered to be of 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 water pollution control: Proper treatment of all wastewater and produced water discharges will be made to ensure that they comply with criteria set by the regulatory body (MoEF and SPCB) 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. An oil-
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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 No ground water extraction will be undertaken to cater the domestic requirement of operational workforce, drilling mud preparation and flushing of blast holes. Therefore the impact is anticipated to be of low significance.
Severity of Impact 2 Extent of Impact 2 Duration of Impact 1 Impact Significance = 4 i.e. Low
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 exploratory block region due to proposed exploratory drilling operations are discussed below:
Loss of flora and floral habitat It has been observed that 6 wells i.e. RBK-1, RBK-2, RLBK-1, RTDN-1, RPAA and RJDR are located on agricultural land where no prominent vegetation was observed except seasonal crops. On the other hand, four (4) wells i.e. RPAA, RBK-3, RTNG-1 and RTDN-2 are located on the forest land. It is to be mentioned here that RBK-3 well is located in Barak RF
SENES/K-20200/ December 2013 124 ONGC EIA Studies for Exploratory drilling at Pre-NELP Block AA-ONJ/2 whereas, RTNG-1 and RTDN-2 wells are located in Inner Line RF. Other wells i.e. RJDR, RTDN-1, RBK-1, RBK-2, RLBK-1 are located in close proximity with these reserve forest. Therefore utmost care will be taken to conserve the floral diversity of these areas. The clearance of vegetation in the R.F. will be undertaken after taking necessary Forest Clearance and Compensatory afforestation. Reviewing of ecological conditions of the exploratory block 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 Amongst 9 exploratory drill sites, RBK-3, RTNG-2 and RTDN-2 are located in Barak RF and Inner Line RF. RJDR and RTDN-1 is located within 1km of Lower Jiri RF and Inner Line RF respectively. On the other hand, distance of RLBK-1 and RBK-2 from Lower Jiri RF is calculated as 4.3km and 12 km respectively. As these Reserve Forest are famous for Bird siting, therefore utmost care will be undertaken by the project proponent to keep the faunal diversity of these areas. Considering the nature of project activity, it may be stated that the existing habitats, except for areas to be cleared, i.e. for site preparation in RBK-3, RTDN-2 and RTNG-1 and for approach road construction for RPAA, RTDN-2 and RTNG-1, other areas will not undergo any further degradation. 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
Impact on Endangered/Threatened Flora and Fauna As discussed in 4.2.10, the exploratory block falls under Lower Jiri RF, Barak RF and Inner Line RF. Further it has been illustrated during baseline profiling of Ecological Environment (Section 3.2) that the study area is habitat 29 mammalian species, 89 avian species and 25 reptilian species. Additionally two (2) Schedule I bird species and eight (8) Schedule-I mammalian species is native to this exploratory block. In view of this, project proponent will undertake adequate measures to maintain the biological diversity of the study area. Noise, vibration and light generated during drilling (operation of the rig) are expected to cause significant impact on protected animal species.
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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 biological environmental section of the report, the nearest wild life sanctuary from the study area is Borail WLS located at an approximate distance of 24 km. No other WLS are coming under 10km radius of the study area. Additionally, the block is not declared as a designated Elephant corridor. Taking all these scenarios into consideration, no major impact is anticipated on Sensitive Ecological Habitat due to drilling activity within the block. Severity of Impact 2 Extent of Impact 1 Duration of Impact 2 Impact Significance = 4 i.e. Low
Aquatic Habitat, Aquatic Flora & Fauna The major rivers viz. Barak, Sonai, Jiri, Rukni and Chiri forms the aquatic ecosystem in the study area. 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. Therefore, in case of any discharge of untreated waste water from exploratory 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 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 1 Impact Significance = 4 i.e. Low
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 9 exploratory wells, six (6) wells are located in a private land. Approximately, 2.25 ha land will be required for construction of each well for proposed drilling activity. The agricultural lands are mono-crop land with moderate vegetation cover. The land will be taken on a lease basis and necessary payments
SENES/K-20200/ December 2013 126 ONGC EIA Studies for Exploratory drilling at Pre-NELP Block AA-ONJ/2 will be made against it along with 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 1 Extent of Impact 2 Duration of Impact 2 Impact Significance = 4 i.e. Low
Conflicts on Job Opportunity Primary survey and public consultation showed that the local people desired to work with ONGC. 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, and small businessmen. Local people are strongly objected to outsiders, and demanded that major proportion of workers will be involved from surrounding villages. Considering public opinion, impact will be low.
Severity of Impact 2 Extent of Impact 2 Duration of Impact 1 Impact Significance = 4 i.e. Low
Disruption on Infrastructure Road network within the block are observed that main roads i.e. approach roads are pucca in nature and internal village roads are Kutcha road. Transportation of drilling rig and associated facilities to drill and decommissioning of rig and associated structure 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 approach 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. 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 exploratory drilling activity stands temporarily affected during the entire lifecycle of the project. Reinstatement of
SENES/K-20200/ December 2013 127 ONGC EIA Studies for Exploratory drilling at Pre-NELP Block AA-ONJ/2 ecological productivity will be dependent on successful restoration of soils, their structure, 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, the 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 phase of exploratory drilling. The drill site will involve the operation of about 50 onsite workers in 2 shifts. 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 negligible. Severity of Impact 1 Extent of Impact 2 Duration of Impact 1 Impact Significance = 2 i.e. Low
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 exploration activities. There are no designated historical or cultural spots within Oil Block. 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
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
SENES/K-20200/ December 2013 128 ONGC EIA Studies for Exploratory drilling at Pre-NELP Block AA-ONJ/2 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 duration. It is proposed that first preference be given to people whose land is taken on a lease basis 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. 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
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 as well as approach 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
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TABLE 4-6: IMPACT SIGNIFICANCE MATRIX (WITH MITIGATION)
Environment Physical Environment Biological Environment Socio-economic Environment
e
&Endangered
&Visuals
Population Population
Activity
Aesthetics Aesthetics AirQuality NoiseQuality & Traffic Transport Use Land SoilQuality Habitat & Flora Floral Habitat Wildlife Fauna Threatened species &rout 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 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 L 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 L L L + L Consumption of water for construction & domestic use for labourer L L Generation of domestic solid waste & disposal L L L L L L 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. Exploratory Well Drilling & Testing Physical Presence at drill site L M M M Operation of DG sets and machinery L M H H H L M M
Operation of drilling rig M H H H L M M Storage and disposal of drill cuttings and mud L L L L Generation of process waste water & discharge M L L L Surface run-off from drill site L L L L Generation of domestic waste water & discharge L L L L L Generation of Municipal waste & disposal L L L L Workforce engagement & accommodation at drill site L L L + M Flaring during production testing and process upset L M M H H H L M M Accidental events - blow out L M M M M H H H L 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 (QRA)
This section on Quantitative Risk Assessment (QRA) aims to provide a systematic analysis of the major risks that may arise as a result of onshore exploration activities by ONGC in AA- ONJ/2 Block. 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 onshore exploration activities has considered all aspects of operation of the drilling rig and other associated activities during the exploratory phase. Oil spills, loss of well control / blow-out and process leaks constitute the major potential hazards that may be associated with the proposed onshore exploratory drilling for oil and gas in the AA-ONJ/2 Block. The study however does not examine the risks or hazards associated with development and production program of the exploratory 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-20200/ December 2013 131 ONGC EIA Studies for Exploratory drilling at Pre-NELP Block AA-ONJ/2 principle. Hence in order to ensure effective management of any emergency situations (with potential individual and societal risks) that may arise during the exploratory drilling activities, following specific objectives need to be achieved. Identify potential risk scenarios that may arise out of proposed drilling and other associated activities like operation of ancillary facilities and equipment’s, mud chemicals storage and handling etc. Analyze the possible likelihood and frequency of such risk scenarios by reviewing historical accident related data for onshore & offshore 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 exploratory 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 exploratory drilling operations 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 ONGC 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 AA-ONJ/2 block, 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 ONGC. 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 ONGC’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 risks5. 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 operations6 ,relevant offshore accident databases have been considered in 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,
5 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.
6 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.
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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 exploratory 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-20200/ December 2013 136 ONGC EIA Studies for Exploratory drilling at Pre-NELP Block AA-ONJ/2 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. 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
Major 4 20 16 12 8 4
Moderate 3 15 12 9 6 3 Consequence Consequence 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
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 exploratory drilling activities. A comprehensive risk assessment study
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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 an exploratory or producing well. 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 Outs7 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 and development 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.
7 “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 data8 has been considered to be 7.5 X 10-3 per well drilled. Based on the given frequency and information provided by ONGC on the proposed project exploratory drilling program the blow out frequency is calculated as follows:
No of exploratory wells to be drilled = 9 (A) Blow out frequency for exploratory drilling = 7.5 X 10-3 per well drilled (B) Frequency of blow out occurrence for the proposed project = (A X B) = 9 X 7.5 X 10-3 = 6.75 X 10-2 per well drilled
Thus, the blow out frequency for the proposed project is calculated at 1.65 X 10-1 per well drilled i.e. the likelihood of its occurrence is “Occasional/Rare”
Blowout Ignition Probability Review of SINTEF database indicates that a rounded ignition probability of 0.3 has been widely used for the purpose of quantitative risk analysis arising from blow outs. As per this database generally ignition occurred within first 5 minutes in approximately 40% of the
8 Analysis of the SINTEF database for the US GoM OCS/North Sea for the period 1980-92 by Scandpower (1995)
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EIA Studies for Exploratory drilling at Pre-NELP Block AA-ONJ/2 ignited blowouts leading to either pool and/or jet fire with gas having a greater probability of ignition compared to liquid releases9 (Figure 5.3).
FIGURE 5-3: IGNITION PROBABILITY VS RELEASE RATE
Further on analysis of the ignition trends over the years it is observed that there has been a decline in ignition probability hence an average ignition probability of 0.1 (Holand) has been considered for QRA of the proposed exploratory drilling project.
No of exploratory wells to be drilled = 9 (A) Blow out frequency for exploratory drilling = 7.5 X 10-3 per well drilled (B) Blow out ignition probability = 0.1 (C) Probability of Blow out ignition for the proposed project = (A X B X C) = 9 X 7.5 X 10-3 X 0.1 = 6.75 X 10-3 = ~ 0.0067% Hence based on the aforesaid calculation the probability of ignition of blow out releases of hydrocarbons for the proposed exploratory drilling project will be about ~0.0067% and can be considered as negligible.
Blowout Consequence Analysis Blow out from a hydrocarbon exploratory and/or producing well may lead to the following possible risk consequences: Pool fires and smoke plumes resulting from ignited oil blow outs
9 Fire and Explosion – Fire Risk Analysis by Daejun Change, Division of Ocean System and Engineering
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Jet fires resulting from ignited gas blow outs Oil slicks resulting from un-ignited oil pools.
Most crude oils are more than 95 percent carbon and hydrogen, with small amounts of sulfur, nitrogen, oxygen, and traces of other elements. Crude oils contain lightweight straight- chained alkanes (e.g., hexane, heptane); cycloalkanes (e.g., cyclyohexane); aromatics (e.g., benzene, toluene); cycloalkanes; and heavy aromatic hydrocarbons (e.g., polycyclic aromatic hydrocarbons [PAHs], asphaltines). Based on the above discussion and also given the limitation of ALOHA software with respect to risk modeling of crude oil releases, n-heptane has been considered as the representative substitute of crude oil for ALOHA based risk modeling for hydrocarbon releases for the proposed exploratory drilling project. For natural gas releases leading to jet fire, modeling has been based considering methane which represents nearly 95% of natural gas. 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.
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TABLE 5-7: POOL FIRE DIAMETER & STEADY STATE BURNING AREA Release Release Pool diameter Steady State Scenario Rate (kg/s) Type (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 risk scenarios viz. pool fire as discussed in above for the proposed project has been modeled using ALOHA10 and interpreted in terms of Thermal Radiation Level of Concern (LOC). Predominant local meteorological conditions as specified in the baseline chapter have been considered in modeling the safety risks/hazards using ALOHA.
Thermal Radiation Level of Concern (LOC) is a threshold level of thermal radiation, usually the level above which a hazard may exist. For each LOC chosen, ALOHA estimates a threat zone where the thermal radiation is predicted to exceed that LOC at some time after a release begins. These zones are displayed on a single Threat Zone plot displayed as red, orange and yellow with red representing the worst hazard. The threat zone displayed by ALOHA represent thermal radiation levels and also indicates the effects on people who are exposed to those thermal radiation levels but are able to seek shelter within one minute. ALOHA uses three threshold values (measured in kilowatts per square meter) to create the default threat zones: Red: 10 kW/ (sq m) -- potentially lethal within 60 sec; Orange: 5 kW/ (sq m) -- second-degree burns within 60 sec; and Yellow: 2 kW/ (sq m) -- pain within 60 sec
The impact zone for long duration fires is conveniently described by overlaying the thermal radiation contours of worst case scenario (50 kg/s of crude oil release) on the land use map of the each exploratory well site. These risk contour maps will prove to be of assistance to ONGC to identify villages and other sensitive receptors, which may fall within the potential threat zone thereby ensuring better preparedness in terms of risk control and mitigation at project design stage. Well site risk contour maps for worst case scenario prepared based on ALOHA modeling of pool fire risks has been presented in Figure 5.4-5.12 below.
10 ALOHA is a public domain computer code that is part of a system of software that is known as the Computer-Aided Management of Emergency Operations (CAMEO) that was developed by the United States Environmental Protection Agency (EPA), through its Chemical Emergency Preparedness and Prevention Office (CEPPO) to plan for and respond to chemical emergencies
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FIGURE 5-4: RBK-1 WELL SITE - POOL FIRE RISK CONTOUR MAP
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FIGURE 5-5: RBK-2 WELL SITE - POOL FIRE RISK CONTOUR MAP
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FIGURE 5-6: RPAA WELL SITE - POOL FIRE RISK CONTOUR MAP
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FIGURE 5-7: RBK-3 WELL SITE - POOL FIRE RISK CONTOUR MAP
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FIGURE 5-8: RLBK-1 WELL SITE - POOL FIRE RISK CONTOUR MAP
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FIGURE 5-9: RTDN-1 WELL SITE - POOL FIRE RISK CONTOUR MAP
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FIGURE 5-10: RJDR WELL SITE - POOL FIRE RISK CONTOUR MAP
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FIGURE 5-11: RTNG-1 WELL SITE - POOL FIRE RISK CONTOUR MAP
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FIGURE 5-12: RTDN-2 WELL SITE - POOL FIRE RISK CONTOUR MAP
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The thermal radiation threshold values (measured in kilowatts per square meter) defined for crude oil pool fire consequence modeling for various hypothetical scenarios as discussed in the earlier section is provided in Table 5.8 below:
TABLE 5-8: DISTANCE TO THERMAL RADIATION THRESHOLD LEVELS Distance to Distance to Distance to Release Pool fire Pool fire 10.0 kW/m2 5.0 kW/m2 2.0 kW/m2 Type diameter (m) area (m2) (m) (m) (m) Small 5.05 6.37 11 17 28 Medium 15.96 63.69 37 55 87 Large 35.69 318.47 84 120 187
The worst hazard for release and ignition of crude oil release at a rate of 50kg/s for a thermal radiation intensity of 10.0 kW/m2 is likely to be experienced to a maximum distance of 84m from the source with potential lethal effects experienced within 1 min. Interpretation of the well site risk contour maps reveals that no community settlements falls in the “Red” Threat Zone except for RLBK-1, RTDN-1 and RJDR exploratory well sites. Hence additional care needs to be taken by ONGC to enhance emergency management preparedness at these well sites in accordance to the Disaster Management Plan. Risk Ranking – Blowout Pool Fire (Worst Case Scenario)
Likelihood ranking 3 Consequence ranking 4
Risk Ranking & Significance = 12 i.e. “Medium”
Ignition of Flammable Gas Release leading to 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 5.9) have been considered for nature gas release consequence modeling:
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TABLE 5-9: NATURAL GAS RELEASE MODELING SCENARIOS Scenario Release Rate (kg/s) Release Type Scenario - I 1 Small Scenario - II 5 Medium Scenario – III (Worst Case) 10 Large As in the case of pool fire, modeling of nature gas releases has also been carried out using ALOHA. A Flammable Level of Concern approach has been utilized for assessing safety risk associated with the release of flammable gases (here methane) from well blow outs. In ALOHA, a flammable Level of Concern (LOC) is a threshold concentration of fuel in the air above which a flammability hazard may exist. While modeling the release of a flammable gas that may catch on fire—but which is not currently burning—ALOHA can predict the flammable area of the vapor cloud so that flammability hazard can be established. The flammable area is the part of a flammable vapor cloud where the concentration is in the flammable range, between the Lower and Upper Explosive Limits (LEL and UEL). These limits are percentages that represent the concentration of the fuel (that is, the chemical vapor) in the air. If the chemical vapor comes into contact with an ignition source (such as a spark), it will burn only if its fuel-air concentration is between the LEL and the UEL—because that portion of the cloud is already pre-mixed to the right mixture of fuel and air for burning to occur. If the fuel-air concentration is below the LEL, there is not enough fuel in the air to sustain a fire or an explosion—it is too lean. If the fuel-air concentration is above the UEL, there is not enough oxygen to sustain a fire or an explosion because there is too much fuel—it is too rich. When a flammable vapor cloud is dispersing, the concentration of fuel in the air is not uniform; there will be areas where the concentration is higher than the average and areas where the concentration is lower than the average. This is called concentration patchiness. Because of concentration patchiness, there will be areas (called pockets) where the chemical is in the flammable range even though the average concentration has fallen below the LEL. Because of this, ALOHA's default flammable LOCs are each a fraction of the LEL, rather than the LEL itself. ALOHA uses 60% of the LEL as the default LOC for the red threat zone, because some experiments have shown that flame pockets can occur in places where the average concentration is above that level. Another common threat level used by responders is 10% of the LEL, which is ALOHA's default LOC for the yellow threat zone. The flammable LOC threat zones for methane release are as follows: Red : 26,400 ppm = 60% LEL = Flame Pockets Yellow: 4,400 ppm = 10% LEL Well site risk contour maps for worst case scenario prepared based on ALOHA modeling of natural gas releases for flammable vapour cloud has been presented in Figure 5.13-5.21 below.
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FIGURE 5-13: RBK-1 WELL SITE – RISK CONTOUR MAP FOR NATURAL GAS RELEASE
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FIGURE 5-14: RBK-2 WELL SITE – RISK CONTOUR MAP FOR NATURAL GAS RELEASE
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FIGURE 5-15: RPAA WELL SITE – RISK CONTOUR MAP FOR NATURAL GAS RELEASE
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FIGURE 5-16: RBK-3 WELL SITE – RISK CONTOUR MAP FOR NATURAL GAS RELEASE
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FIGURE 5-17: RLBK-1 WELL SITE – RISK CONTOUR MAP FOR NATURAL GAS RELEASE
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FIGURE 5-18: RTDN-1 WELL SITE – RISK CONTOUR MAP FOR NATURAL GAS RELEASE
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FIGURE 5-19: RJDR WELL SITE – RISK CONTOUR MAP FOR NATURAL GAS RELEASE
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FIGURE 5-20: RTNG-1 WELL SITE – RISK CONTOUR MAP FOR NATURAL GAS RELEASE
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FIGURE 5-21: RTDN-2 WELL SITE – RISK CONTOUR MAP FOR NATURAL GAS RELEASE
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The zone of flammable vapour cloud calculated for hypothetical natural gas release under risk scenarios discussed in the earlier sections have been presented in the Table 5.10 below.
TABLE 5-10: ZONE OF FLAMMABLE VAPOUR CLOUD – NATURAL GAS RELEASE SCENARIOS Release Release Rate Red – 60% Yellow -10% Type (kg/s) LEL (m) LEL (m) Small 1 53 161 Medium 5 124 325 Large 10 178 419
Hence for a worst case scenario (10kg/s) the flammable vapor cloud zone/flame pockets’ resulting from accidental release of natural gas will be covering a radial zone of 178m from source with the flammable gas concentration within this zone being 26,400 ppm. This is of particular significance for the RBK-1, RLBK-1, RTDM-1 and RJDR exploratory well sites where community settlements are observed to fall within this “flame pocket” zone (Refer Figure 5.13 to 5.21) and may lead to potential safety risks/hazards following any ignition. Risk Ranking – Blowout Natural Gas Release (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 unignited 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 10-20mm. The spill movement is then resisted by the viscous shear forces which then continue until the spill thickness is about 1.0mm. Subsequently, surface tension takes over as the dominant spreading mechanism and it continues until the thickness has reduced to 0.01 – 0.1mm 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)
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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 diameter so calculated for the aforesaid risk scenarios have been presented in the Table 5.11 below.
TABLE 5-11: 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 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 exploratory 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 ONGC.
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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 drilling and their possible mitigation measures. Installation of mass communication and public address equipment. Good layout of well site and escape routes.
Additionally, ONGC will be adopting and implementing the following Safe Operating Procedures (SOPs) developed as part of its Onsite Emergency Response Plan to prevent and address any blow out risks that may result during drilling and work over activities:
Blow Out Control Equipment Choke lines and Choke Manifold Installation with Surface BOP Kill Lines and Kill Manifold Installation with Surface BOP 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 5.12 below.
TABLE 5-12: 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
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Frequency Equipment Type (per equipment item year) 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 exploratory drilling for the proposed project to span over a period of 2 months or 0.16 years , frequency analysis for the process leaks from various process equipment is calculated as follows (Table 5.13)
Table 5-13: 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 0.16 1.40 X 10-5 Not Likely Valves 2.3 X 10-4 0.16 0.36 X 10-4 Not Likely Small Bore Fitting 4.7 X 10-4 0.16 0.75 X 10-4 Not Likely Pressure Vessel 1.5 X 10-4 0.16 0.24 X 10-4 Not Likely Pumps, centrifugal, 1.7 X 10-2 0.16 0.27 X 10-2 Occasional/Rare double seal Pumps, reciprocating, 3.1 X 10-1 0.16 0.49 X 10-1 Occasional/Rare double seal Compressors, 1.4 X 10-2 0.16 0.22 X 10-2 Occasional/Rare centrifugal Compressors, 6.6 X 10-1 0.16 1.05 X 10-1 Occasional/Rare reciprocating
Thus, as discussed above in most of the cases the frequency of occurrence of process leaks for the proposed project is “Not Likely” with hydrocarbon release from reciprocating pumps and compressor is analyzed to be as “Occasional/Rare”. Further, taking into account that ONGC 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.
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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 database for major and minor process leaks indicated the following generic ignition probabilities (Table 5.14).
TABLE 5-14: 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 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 exploratory 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;
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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. 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 onshore exploratory 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 5.15 below:
TABLE 5-15: 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.
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Risk Ranking for Non-Process Fires
Likelihood ranking 3 Consequence ranking 1
Risk Ranking & Significance = 3 i.e. “Low”
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 exploratory and development 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 and pipeline accident events 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
SENES/K-20200/ December 2013 171 ONGC EIA Studies for Exploratory drilling at Pre-NELP Block AA-ONJ/2 procedures can be effectively implemented by the ONGC Emergency/Crisis Management Team. The emergency levels/tiers defined with respect to this project based on their severity have been discussed in the subsequent sections with 'decision tree' for emergency classification being depicted in Figure 5.22.
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
FIGURE 5-22: EMERGENCY CLASSIFICATION “DECISION TREE”
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.
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5.4.5 Level 2 - Emergency It is an event which may be dealt by the ONGC 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 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 ONGC 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; ONGC 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 5.23 below.
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
FIGURE 5-23: EMERGENCY RESPONSE LEVELS
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5.4.7 ONGC Disaster Management Plan ONGC has in place a Disaster Management Plan which has been developed to set up the appropriate mechanism and course of action to mitigate the impact of an Emergency event viz. blow out, fire, explosion etc. The plan provides a procedure allowing all those involved in and outside ONGC to mobilize their resources in an orderly manner and react effectively in time. The plan therefore, aims at immediate response to an Emergency event to prevent escalation to a Disaster and also the response in the event of such escalation. The plan will be updated as and when necessary, but at least once in every year by Basin HSE in consultation with Surface Team, Sub surface Team, Drilling Services and Well Services Group. Also ONGC has been accredited with ISO 9001:2008; 14001:2004 and OHSAS 18001. The roles and responsibilities of both ONGC emergency response team to combat with any emergency situation as discussed in the earlier section are presented in the Table 5.24 below while the details of the resources available onsite with the Crisis Management Team to control key emergency events particularly blow outs has been presented in Annexure 5.1.
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FIGURE 5-24: ONGC ON-SITE DISASTER MANAGEMENT TEAM PROFILE Sl. Response Location Facilities Functions No. Team/Resource 1 Site Control In case of Emergency at Site, a Emergency vehicle, Communication Assessment of situation and requirements, tor Room Site Control Room will be set facilities, Mobile Van, Ambulance, mobilization of equipment / resources etc. up at a safe distance near the Lighting arrangement and Food shall To pass on the information regarding latest positions Site. be provided at the SCR in the to Emergency Control Room minimum possible time. To keep record of all decisions and messages received To keep records of all materials received at site during Emergency. 2 Emergency The control room will function To be equipped with good Command and Control of entire Operations. Control Room from Drilling Services (DBC) communication facilities like Round the clock monitoring and flow of information (ECR) Control Room, Jorhat Telephone (2 nos.), Radio to & from the site of Emergency. Equipment, Wall Chart showing Maintenance of running record of events and action Locations of Installations, fire taken station, copy of the Disaster Casualty list and information to next if Kin. Management Plan. Preparation of Management Report on the situation at every 12 Hrs. interval. Co-ordination with the key personnel's for guidance and assistance required at site. Co-ordination with other Oil companies Co-ordination with Local authorities — Police, Civil Administration, Hospital & Fire. Sanction and procurement of the items required during Emergency. Arrangement of food, water, shelter, medicine& logistics etc., Information to Public. Co-ordination -with Regions / Projects and Head — Quarter.
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Sl. Response Location Facilities Functions No. Team/Resource Co-ordination with fire brigade & fire tender facilities available with different organizations nearby. 3 On Scene At initial stage, someone close - Initial assessment at the spot and need for Commander enough to the scene of mobilization of sources. (OSC) Emergency (Installation Inform Emergency Control Room in case, the manager / DIG / senior most communication is lost due to disaster. Seek person) will exercise as On assistance from nearby rig or installation for Scene Coordinator. He will take communication. the charge of the situation In case of fire, commands the firefighting operations immediately. till tire service assistance reaches on the scene. Arrange Ambulance & doctor if required.
4 Chief Emergency The Head of the concerned - Will keep record of messages and decisions taken to Coordinator Operational Group will be the control the Emergency. He will also appraise the Chief Emergency Coordinator Basin Manager from time to time on steps taken to and will exercise control control the situation and status of Emergency. through ECR. 5 Regional Crisis Regional Crisis Management - Familiarize itself thoroughly with the manual and its Management Team comprises of officers implications Team (RCMT) having experience in handling To plan strategies for different Crisis situation so major emergency. The RCMT that all necessary inputs can be mobilized without is expected to be informed loss of time. Frequent mock drill be carried out. within 30 minutes of In the event of Crisis, go to the scene of Emergency, occurrence of incident by the assess the situation and take over all fronts out and / Mines Manager / Emergency or fire up o the point of normalizing the well. Control Room. The Team will Determine the type of assistance required for immediately proceed to the handling the Emergency. location and take action to bring the situation under control. To seek guidance and assistance from coordinator group.
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Sl. Response Location Facilities Functions No. Team/Resource Updating the action plan of Disaster management on the basis of their experience. Keep them well informed of the technical development through various journals / magazines, suggest scope of improvement in equipment and practices. 6 Support Services The Support Services Group - Support Manager Group will comprise of coordinators from Central Workshop, To identify location of relief camp at a safe distance Electrical, Civil, Logistics, from the affected area and arrangement for shelter E&T, Health Services and (tent, cot, chair, blanket etc.) P&A, Geology and Reservoir To arrange food, drinking water, beverage at relief etc. They will provide all camp necessary help required by Maintenance of record of Casualties emergency control room / Site Control Room / RCMT and be Co-ordinate with local Authorities. in constant touch with Fire Services Emergency Control Room and may have to stay at the site of Mobilize firefighting person and equipment onsite. Emergency Information & Communication’s Manager Ensure Communication facilities Set up Emergency communication (Walkie-talkie, VHF etc.) at the Site Control Room. Electrical Arrangement of Emergency Gen. Set and Flame proof lighting at the site. Logistics Arrangement of transport facilities, cranes, moles etc for man and material.
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Sl. Response Location Facilities Functions No. Team/Resource Material Management To assist in issuing of materials Arrangement of equipment, materials, expertise etc., as per requirement of Emergency Control Room / RCMT. Civil Civil jobs such as construction of temporary road, control of Oil spread by sand bags or digging of pits, water pumping and storage arrangement etc. Security Deployment of Security personals at vulnerable locations. Cordoning off the affected site. Police Help Sub surface Team (Geology & Reservoir) To assist in Geological / Reservoir information about the well Medical Services Mobilize first — aid team with adequate medical facility and ambulance at Emergency site. Corporate Communication (PRO) Press briefing with approval of Basin Manager
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For Level 3 emergency (refer Figure 5.23) apart from the mobilization of onsite Emergency Response Team as referred above ONGC also need to activate the off-site Disaster Plan to safeguard the lives and properties of nearby communities with the assistance/support from local/district authorities
Local/District Authorities – Roles and Responsibilities I. Deputy Commissioner/ Addl. Deputy Commissioner Take overall responsibility for combating the Off-site Emergency, Declare an area of 2 km around the site as Emergency zone. Direct the District Police, Fire services for warning and evacuating the public. Direct the team of Doctors headed by the District Medical Officer to attend the affected people. Direct the Revenue Officer of the District to provide safe shelter, food and other life sustaining requirements for the evacuees. Direct the District Transport Officer to arrange for transportation of victims and evacuation of the people trapped within the Emergency zone.
II. Superintendent of Police Mobilize force to the site of Emergency on receipt of instruction from DC / Addl. DC to cordon off the affected site / area and disperse the unwanted crowd for easy fire fighting operation / rescue operation. Post adequate nos. of Police personnel in the following places. In all the evacuated areas to provide security to the properties of the evacuees. In the entire Road junction outside the emergency zone to control traffic and priority for movement of fire tender ambulance etc. Warning and advising the affected population through unambiguous, reliable and rapid announcement by the SDIPRO/DIPRO. The information to be given to the public should be the nature of the incident, the degree of the incident; the steps taken to control the situation and the Emergency counter measures. The announcement shall be both in Assamese and Hindi. Liaison with the Medical co-coordinator for post mortem of the dead bodies, if any, Any other action as desired by the Dy. Commissioner.
III. District Transport Officer On receipt of the request from Emergency Control Room, ONGC, the Transport Officer shall arrange for the dispatch of vehicle to reach the Emergency site immediately. The dispatched vehicle shall be at the disposal of ONGC until the release order is issued. He also takes up the action as directed by the Dy. Commissioner / Addl. Dy. Commissioner.
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IV. District Medical & Health Officer On receipt of information form Dy. Commissioner / Addl. Dy. Commissioner about the Emergency, the District Medical Officer shall extend the facilities available at the Hospital and make the services of the trained Doctors to provide necessary medical care for Emergency medical cases. He shall ensure that the Primary Health Centers & Municipal Dispensaries are equipped with required quantities of drugs & equipments. V. District Fire Officer Shall assist in Fire Fighting in case of Off-site Emergency and rescue operations in the affected area with the help of Civil defense / Home guards etc. VI. Officer in-charge of Relief Camp An officer in the cadre of Revenue Inspector shall be the In-charge of the Relief camps. He shall maintain a record of the evacuees under the headmen, women and children. The department concerned at the Relief Camps shall provide the following facilities. Sanitation: This is very important at the Relief Camps. A team of Sanitary Inspector shall attend the camp round the clock. Latrine facilities shall be provided. Water: Municipal Board shall arrange storage of Water. Lights: Assam Electricity Beard shall arrange Electric Lights at the Camp. VII. District Veterinary & Animal Husbandry Officer Shall depute as many persons as required (taking in to account the number of Cattle especially milking animals in the affected areas) to look after the welfare of the cattle and protect their lives by applying precautionary measures. He shall also be responsible for arranging food for the Cattle during Emergency. VIII. District Agriculture Officer Will prepare an action plan to protect the food grains / standing crops in the Emergency affected area and will take action accordingly. IX. Station Director (Door-Darshan) On receipt of the message from the Superintendent of Police, he will immediately telecast the Emergency message as given by the Police authority, if required. Similarly, he will also arrange to telecast periodic review message and completion of Emergency / all clear message. The section below highlights the sequential action to be performed by the ONGC Emergency Response Team along with drilling personnel under various emergency situations viz. blow outs, fire and explosion etc. The list of equipment for blowout control is presented in Annexure 5.1
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Action Plan – In event of Blow Outs The following actions shall be taken by the Shift — in charge to bring the situation under control. (A) On experiencing Kick, following safety actions to be taken, it BOP fails to seal Well Mouth 1 Alert Crew to ensure escape if situation worsens Action : Shift I/C 2 Divert flow partially, intermittently or fully to waste pit (safe distance) Action : Drilling Crew 3 Send SOS message (i) By EPABX (ii) By Emergency Vehicle Action Shift I/ C 4 Switch off all Engines / Generators Action: I/C Mech. / Elect. 5 Remove all inflammable material away Action: Rig Crew (Drilling / Mech. / Elect.) 6 Remove important Records to Safe place Action: Rig Crew (Drilling / Mech. / Elect.) 7 Remove costly instruments / equipments to safe place Action: Rig Crew (Drilling / Mech. / Elect.)
(B) If the Blow out is sudden and massive while initial safety action could not be performed. 1 Carry out rescue operation for Top man and move other Rig Crew to safe distance. Action : Shift I/C 2 Send SOS message by Phone and by Emergency vehicle Action : Shift I/C 3 Reorganize to try operations like BOP, Diversion of flow etc., as listed in (A), if situation permits, Action : Shift I/C 4 If heavy spillage occurs, try to contain in the restricted area Action : Shift I/C 5 Alert the inhabitants, if private residence is near Action : Geologist / Chemist
As soon as an Emergency is declared and the site is evacuated, Site Control Room will be established near the Drill site at a safe distance.
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Action Plan – Process Leak / Loss of control resulting in Fire and Explosion 1 Shout "FIRE'', "FIRE", "FIRE", "AAG", “AAG", “AAG", "JUI', "JUI', "JUI”,.... In case of fire 2 Inform Shift. In-charge/Site In-charge at first site of Fire / heavy Gas leakage / Oil spill Action: Person who notices the incident first. 3 Inform Field Fire Station, Base Fire Station and Base Control Room Action: Shift I/C. Site I/C. 4 Identify the Source of leakage, isolate and attempt to extinguish tile Fire with hand held Fire Extinguisher. Action: Shift I/C. Site I/C. 5 Nearby source of ignition should be cut off immediately (like stoppage of the cutting / welding jobs, stopping engines, switching off the Electricity etc. Action: Shift I/C. Site I/C. Elect. I/C. Mech. I/C. 6 Start Fire water pumps and pressurized Fire Header to extinguish Fire Action: Mechanics / Shift Operator 7 Inform other GGS to stop supply of Oil & Gas to the affected Installation. Action: Shift I/C. Site I/C. 8 If needed, close all wells and shut down the Installation under Emergency conditions. Action: Shift I/C. Site I/C. 9 Release over pressure wherever required. Action: Shift I/C. Site I/C. 10 Inform nearby Installation for Help. Action: Shift I/C. Site I/C. 11 If heavy spillage occurs, try to contain in the restricted area. Action: Shift I/C. Site I/C. 12 Fire crew In-charge after arriving at Site will report to the Shift in-charge /Installation In-Charge and access the situation and position the Fire tender at appropriate place from where it can be fought effectively. Action: Fire Crew I/C. 13 The quantum of spillage / Gas leakage shall be briefed by the installation I/C to Fire in- charge for Fire fighting Action: Fire Installation I/C. 14 Cooling and quenching of nearby pressure vessel / tanks to be carried out Action: Fire crew 15 All persons present at the site should assist the Fire crew in tire fighting. Action: All persons present at site 16 Continuous monitoring of Gas concentration should be done. Action: Safety Officer/Asst. Shift I/C 17 Entry at Main Gate should be regulated and Contract personals should be removed from the affected site by CISF. Action: Area Commander CISF 18 Pass the information and progress to Emergency Control Room at regular intervals. Action: Installation I/C., Field I/C.
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6 Environmental Management Plan & Monitoring Framework This Environmental Management Plan and Monitoring Framework is a site specific document for the exploratory, development and testing of hydrocarbons that has been developed to ensure that ONGC 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 ONGC’s activities within the block. This EMP will be backed up by more specific Environmental Action Plans, Procedures and Bridging Documents with the progress of the well site preparation, exploratory and development 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 ONGC is presented at Box 6.1.
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Box: 6.1: ONGC Corporate Environment Policy
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6.1 ENVIRONMENT MANAGEMENT PLANS The Environment Management Plan details out the mitigation measures to be implemented by both ONGC and the Contractors during various stages of the exploratory, development and testing of hydrocarbons within the AA-ONJ/2 block. The following environmental management plans have been formulated in line with the proposed project activities viz. site preparation, exploratory and development drilling, well testing and decommissioning Pollution Prevention and Abatement Plan Waste Management Plan Storm Water and Spill Management Plan Wildlife Management Plan Management of Social Issues and Concerns Site Restoration Plan Road Safety and Traffic Management Plan Occupational Health & Safety Management Plan
ONGC will ensure communication and implementation of the aforesaid management plans prior to the commencement of site preparation and exploratory well drilling operations in the Block. 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 AA-ONJ/2 Block. 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 ONGC and the contractors to ensure effective implementation of the plan. A typical layout of the pollution prevention and abatement plan of a well is given in Figure 6.1.
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The garland drains will be built around the drill pad, waste pits, hazardous waste storage area and the total site. A Mobile ETP will be placed in the site. Oil Spill kit will be placed near HSD tanker and drill pad. Top Soil heap, fluid and chemicals, HSD oil Tanker and Generator will be placed in enclosed bunded areas. Oil-water separator will be placed in the Garland Drains of the site. Adequate lighting will be provided.
Mitigation Measures & Strategies The following mitigation measures need to be adopted and implemented by ONGC 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. A. Control of fugitive and point source emissions
Project Phase Mitigation measures
Construction Siting of exploratory well and borrow areas away from human settlement/habitation and sensitive receptors. Special care will be taken for Wells RBK-1, RBK-2, RLBK-1, RJDR, RTDN1, RPAA as they were located very close (less than 200 m) to human settlement. 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 Bharat Stage III 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 S No. 72 B.1.a Schedule I Standards for Emission or Discharge of Environmental Pollutants from Oil Drilling and Gas Extraction Industry of CPCB. Locations of flare stack will be governed by the presence of habitation and sensitive receptors. Care will be taken as all the proposed exploratory are located very close (less than 200 m) to human settlement. Duration of flaring will be minimized by careful planning;
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Project Phase Mitigation measures 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. Preventive maintenance of DG sets will be undertaken as per manufacturers schedule to ensure compliance with Sl No 95 GSR 371(E) dated 17.5.2002. 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) 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 RBK-1, RBK- 2, RLBK-1, RJDR, RTDN1, RPAA as they were located very close (less than 200 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 in accordance with Sl No 94 GSR 371(E) dated 17.5.2002. 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 plantation) 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. 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 jute mats to avoid erosion by the action of rains/strong winds. 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 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.
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Project Phase Mitigation measures 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 S No. 72 C.1.a Schedule I Standards for Emission or Discharge of Environmental Pollutants from Oil Drilling and Gas Extraction Industry of CPCB as modified in 2005 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 RBK-3, RPAA, RJDR, RTDN-1) 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. 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 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.
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Project Phase Mitigation measures Management of drill cuttings, waste drilling mud, waste oil and domestic waste will be made in accordance with S No. 72 C.1.a Schedule I Standards for Emission or Discharge of Environmental Pollutants from Oil Drilling and Gas Extraction Industry of CPCB as modified in 2005 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.
E. 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 exploratory wells will be sited at a sufficient distance away from an existing tube well or open well. Proper casing and cementing of exploratory 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 S No. 72 C.1.a Schedule I Standards for Emission or Discharge of Environmental Pollutants from Oil Drilling and Gas Extraction Industry of CPCB as modified in 2005 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 ONGC’s proposed exploratory drilling of hydrocarbons in AA-ONJ/2 Block. The major waste streams covered under this plan includes drill cuttings, waste drilling mud cuttings, wash water, kitchen waste and sewage. In
SENES/K-20200/ December 2013 190 ONGC EIA Studies for Exploratory drilling at Pre-NELP Block AA-ONJ/2 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 guidelines11 and also to ensure compliance with ONGC’s corporate HSE Policy. The plan also outlines roles and responsibilities of both ONGC and the contractors involved in the implementation of the plan. Mitigation Measures The following mitigation measures need to be adopted and implemented by ONGC and its contractors for the major waste streams identified in the plan.
Waste Quantity Mitigation Measure Drill Cuttings Above 225 Drill cuttings separated from drilling fluid will be m3/well adequately washed and temporarily stored and disposed in an impervious pit lined by HDPE. 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. Earlier test reports of drill cuttings from AAA Basin has shown the absence of hazardous nature of the soil 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 Mud and 9-10 m3/day Use of water based mud mud or eco-friendly synthetic wash water based mud as the drilling fluid Use of low toxicity chemicals for the preparation of drilling fluid. 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 maximum extent possible.
11 “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 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 S No.72 A(ii) Standard for Liquid effluents of CPCB effluent discharge standard for oil drilling and gas extraction 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 As generated The hazardous waste (waste and used oil) will be managed in accordance with Hazardous Waste (Management, Handling & Transboundary Movement) Used oil 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 9 m3/day per The sewage generated will be treated in a combination of well septic tank and soak pit. Regular supervision will be undertaken for the domestic waste treatment system to report any overflows, leakage, foul odour etc. Lead Acid Batteries 2-3 batteries Will be recycled through the vendors supplying lead acid per well batteries as required under the Batteries (Management & Handling) Rules, 2001. Proper manifest will be maintained as per Batteries (Management & Handling) Rules, 2001.
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Waste Quantity Mitigation Measure Recyclables viz. Depending Proper segregation and storage of recyclable waste in paper, plastic, on usage designated bins onsite. packaging waste etc. Recyclables will be periodically sold to local waste recyclers.
An accounting of usage of hazardous waste will be maintained. In addition to the management measures specified for the major waste stream, ONGC 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 ONGC 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 ONGC and made operational to achieve proper management of all wastes generated on site. A typical layout of the environment management plans in a well site is given in Figure 6.1. The salient features of measures taken to safeguard the environment are given below: The drill pad will be elevated and concretized The top soils will be heaped and bounded by a retaining wall The Waste pits (refer Sec 2.6.1) will be bunded to prevent the overflow of wastewater ETP will be installed Oil spill kits will be available near Drill pad and Oil storage area Fluid and chemicals will be stored in enclosed houses with restricted access The Hazardous waste will be separated from Non-hazardous waste and stored separately in enclosed area Recyclable and non-recyclable waste will be collected and stored separately Sufficient lighting will be provided A garland drain will be constructed within the external boundary of the site that will have a sedimentation tank with oil and water separator
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FIGURE 6-1: ENVIRONMENT MANAGEMENT MEASURES AT DRILL SITE
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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. Obstructions that may cause temporary flooding of local drainage channels, during construction phase will be removed. Oil traps 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 Site Closure Plan
The site closure plan for will identify all the activities which would be performed during the restoration of a particular site in case the well is not economically viable and no further use of that particular well bore is envisaged. Along with the well site the approach road connecting the well will be restored accordingly. Chronological inventory of activities which would be performed during the closure of the site are detailed in this section The following activities have been considered in the closure plan: Plugging & Abandonment of well: Close the well head properly to prevent any further leakage Decommissioning Phase : Removal of the materials form the site
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Waste/mud pit closure and reclamation Reinstatement Phase: regeneration of the land Handover Phase : Returning the land to the original owner
Plugging & Abandonment of well As and when the well will be declared as non productive, plugging of the well will be performed to close and abandon the well to prevent any leakage of oil or gas.
Decommissioning The decommissioning phase includes activities dismantling and removal of surface facilities from the well site, removal of construction fill material form site and storage in the Material Dumping Area. The activities which are envisaged during this phase are: Waste Management: clean up the site and remove all waste materials e.g. HDPE liners, any waste material etc. The waste will be dumped in the designated area as per the guidelines of local pollution control board.
Removing & Dumping of Fill Materials: The fill materials (aggregates, morrum etc) should be removed mechanically from the site. It will be used for the local road preparation or dumped in the designated area as filling material.
Road Restoration: The fill materials should be removed and restore the site or it may be left for further local community use as per the agreement with community.
Waste and mud pit closure and reclamation Following decommissioning and abandonment of the well site the waste and mud pits (4-5 nos) will be subject to closure through onsite burial of solids in accordance with lease and landowner obligations and with local, state and national regulations. Reclamation of closed pits or any other temporary retaining pits, including reserve pits, will be carried out within a period of one year from well closure/abandonment. As Silchar district in Assam is frequented by rains all such reclamation activities will be carried out based on the climatic conditions and will be in accordance with reasonable landowner's wishes, and/or resemble and contour of the adjoining lands.
Reinstatement The reinstatement phase includes all activities for preparation of the soil for agriculture use (if the land is an agricultural land before operation) or forest land. Reinstatement of agricultural land Sub soil preparation: All stones and other foreign material which are visible on the ground would be removed. The sub soil would be tilled till a depth of 6” to de- compaction the soil.
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Overlaying of Topsoil: The topsoil would be spread evenly on each of the terraces as per the thickness specified by the applicable guidelines. Top soil preparation: The bio manure will be mixed with the top soil to increase its fertility (if required). Regular water with mulching will be carried out for more effective soil preparation. If the preserved top soil volume found less than the required volume than make up top soil will be out sourced from soil from pond bottom etc. Seeding of Soil: Seeds of Leguminous crops would be sown on the plots to continuously improve fertility of the soil. Testing of fertility: The soil would be tested for fertility as per the standard procedure of ICAR and compared to the fertility values done during the Pre Project Baseline Environment Assessment. Laying of Plot Dividers: The Plot dividers would be put in place as it was before operation. Sub soil would be used for preparation of the dividers and would be seeded with grass to hold it in place. .
Hand Over These would include all activities to be undertaken for the closing of the land agreement and then handing it over to the original owner.
6.1.5 Wildlife Management Plan Scope The proposed exploratory drilling of hydrocarbons in AA-ONJ/2 Block may impart potential impact on threatened animal species located in forest areas within the AA-ONJ/2 Block. The likely impacts of the project activities on the sensitive 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 and river 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 ONGC 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.
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Mitigation measures The drill site will be properly fenced (chain-linked) to avoid straying of any outsider as well as wildlife, special care should be taken for the well sites RBK-3, RTDN-2, RTNG, RPAA as they are located within or in proximity reserve forests; 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; 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; 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 ONGC 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 exploratory block area and on the material transport route.
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6.1.6 Road Safety & Traffic Management Plan Scope The Road Safety & Traffic Management Plan is applicable to all operation pertaining to ONGC and contractor vehicular movement viz. vehicle involved in the transportation of raw 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 ONGC 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 ONGC 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 will be 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
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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. 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, ONGC 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 53, NH 54, Sonai Road, Binnakandi Road etc.
6.1.7 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 ONGC 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. exploratory/development 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.
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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 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.
6.1.8 Management of Social Issues and Concerns
Mitigation measure have been outlined to address project related social issues and concerns in order for ONGC to take proactive steps and adopt best practices, which are sensitive to the socio-cultural setting of the region. 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.
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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, 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 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 ONGC 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 As AA-ONJ/2 Block is a virgin block, therefore no CSR activities have been undertaken by far. However CSR activities adopted in Cachar district due to operation of ONGC in other blocks and in Mizoram state have been presented in Annexure 6.1. 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. Budget (in Particulars of Work No. lakh 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) 3.6
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Sl. Budget (in Particulars of Work No. lakh Rs.) b. Maintenance of paved internal road and transport route (budgetary provision is included in operational cost of drilling) 0 c. Ambient Air Quality Monitoring -18 monitoring location x once per month x 12 months (@ Rs. 5000 x 18 samples per season x 12 months in a year) 10.8 d. Stack emission monitoring (@ 5000 per sample x 36 sites x monthly once for two months during drilling) 3.6 2 Noise Monitoring a. Ambient Noise Monitoring – 54 locations, once in a month for 12 months(@Rs. 2500 per location x 54 locations x 12 months) 5.4 b. Workplace noise monitoring -6 in each well site during construction, drilling and decommissioning 8.1 3 Water Quality Monitoring
Surface Water Quality Monitoring (@ Rs. 5000 x 3 rivers (four samples) x once each during site construction , drilling and after decommissioning) & ETP inlet outlet, oil/water separator twice during drilling from 9 exploratory wells 1.95 Commissioning and operational cost of ETP (commissioning cost 10 lakhs for 1 ETP; cost; operational cost Rs. 10000 per well X 9 sites) 10.9 4 Soil Quality Monitoring (@ Rs. 4000 x 9samples x once each during site construction , drilling and after decommissioning) 1.08 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 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 – 4nos 0.4 b. Transport arrangement of waste from well sites to dumping area 2 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 wash water 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
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Sl. Budget (in Particulars of Work No. lakh Rs.) 10 Wildlife Management Plan and its approval a. Preparation of Wildlife Management Plan and its approval 0 b. Implementation of Wildlife Management Plan 0 12 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 (ONGC has its own ambulance facility) 0 e Regular occupational health & safety training 3 Total Cost of Implementation of EMP 60.13
It was revealed from the discussion with the locals that there is demand for better road infrastructure, drinking water facilities and health facilities in the area. ONGC will undertake a need assessment for development of infrastructure in the areas that public demanded. The CSR activities of ONGC within the Block will involve; 1. Improvement of road infrastructure 2. Development of surface water based drinking water facilities 3. Provision of health facilities for the local villagers The cost for the CSR activity will be determined after the need assessment studies conducted at the Block.
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Table 6-2: Environmental Management Matrix Sl. Activity Potential Impact Mitigation No Pre-drilling Activities A1 Siting of well site facility Potential adverse impact on environment Selection of drill site taken into account of local environmental vulnerability in 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 Loss of agricultural land and crop Provide compensation for standing crops sites and related facilities productivity Finalization of compensation package in consultation with local communities Loss of livelihood for affected Minimal felling of trees and removal of vegetation through proper and careful communities selection of site. Loss of vegetation cover Plantation of trees to compensate for the loss A3 Site preparation and road Loss of top soil and increase in soil Minimal felling of trees and removal of vegetation through proper and careful strengthening/widening erosion potential selection 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 Generation of fugitive emission Contractor to source raw materials from approved/licensed quarries. raw 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 to be restricted to defined access routes to be identified in consultation with locals and concerned authorities. Proper signage to 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 Selection of low noise generating equipment machinery/equipments generation Installation of engineering controls viz. silencers, mufflers Occupational health and safety concerns Rotation of workers operating in high noise generating areas
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Sl. Activity Potential Impact Mitigation No Use of proper PPEs viz. ear plugs, ear muffs. Periodic preventive maintenance of machinery/equipments A6 Transportation of drilling rig and Generation of fugitive emission Periodic water sprinkling along haulage routes near sensitive receptors ancillaries Community health and safety concerns Project vehicular movement to be restricted to defined access routes to be Disruption of public utilities identified in consultation with locals and concerned authorities. Community health and safety concerns Proper signage to be displayed at important traffic junctions along the predefined access routes. Night time movement of vehicles to be restricted The public utilities viz. telephone and electrical wire to be restored to its original 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. Drilling and Testing B1 Physical presence of drilling rig Temporary change in visual characteristics Restoration of site to its original condition following decommissioning/site and ancillaries of the area closure B2 Operation of DG sets and Air emissions and high noise generation Siting of drilling rig and facilities away from sensitive receptors machinery and exploratory Occupational health and safety concerns Installing acoustic enclosures and muffler on engine exhaust of DG sets drilling 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 Damage to subsurface aquifer Use of low toxicity chemicals exploratory well 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
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Sl. Activity Potential Impact Mitigation No B4 Storage and disposal of drill Soil and ground /surface water Use of water based mud as the drilling fluid. cuttings, mud and process contamination Use of low toxicity chemicals for the preparation of drilling fluid. wastewater 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 to 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 proper spill control equipment. Drill cuttings and mud pit be bunded and kept covered during monsoon. B6 Sewage treatment Occupational health problems of Sewage to be treated using a combination of septic and soak pits operational workforce The sewage treatment system (septic tank & soak pit) to be regularly monitored for any possible overflows, leakages etc. B7 Flaring during production testing Air emission leading to discomfort to Siting of flare stack considering nearest habitation and sensitive receptor. and process upset nearby 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; Decommissioning/Site Closure C1 Dismantling of rig and associated High noise generation and fugitive Rotation of workers operating in high noise generating areas facilities emissions causing discomfort to locals Use of proper PPEs viz. ear plugs, ear muffs. C2 Transportation of drilling rig and Same as in A6 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 to be documented, analyzed and reported internally to Head - HSE. Monitoring requirements have been described in the following Table 6.3. 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 Environmental EPI Performance Indicator Monitoring Parameter Location Period & Frequency Responsibility No. (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 Distance between the drill site and nearest Site Once in project lifecycle Civil supervisor habitation 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 Number of land owners affected Site Once in project lifecycle Civil Supervisor Leased 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 Quarry / Once in project lifecycle Civil Supervisor project site Borrow Area Condition of haul road A.9 Borrowing practices % of contractors sensitized on best practices Borrow Area During site planning HSE Manager & HSE Supervisor and relevant EMP provisions A.10 Undisrupted flow of water in Number of cross drainage structures planned Site & Road Once in project lifecycle Civil Supervisor drainage channels to number of actual stream crossings
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Environmental EPI Performance Indicator Monitoring Parameter Location Period & Frequency Responsibility No. (EPI) B Approach Road & Site Development B.1 Topsoil Area occupied for topsoil storage/ Area Site Once during each site HSE Supervisor planned for topsoil storage preparation B.2 Local drainage pattern Number of Cross Drainage structures Site & road Once in project lifecycle Civil Supervisor constructed to actual number of cross drainage structures designed B.3 Fugitive emission of dust Visual observation of dust in air by haziness Site & approach Daily during site HSE Supervisor with Vehicular / during site preparation roads preparation Civil Contractors
B.4 Air emissions from vehicles PM2.5, PM10, NOx, SO2, CO, HC, VOC Exhausts Once in project lifecycle HSE Supervisor with Civil and machinery based on emission factors Supervisor, Visual observation of emissions (black signifying more pollution) Daily Drilling/Civil Supervisor through HSE Supervisor
% of vehicles possessing valid PUC
Certificates Once in project life cycle Drilling/Civil Supervisor through Drilling/Civil Supervisor through HSE Supervisor, Contractors operating vehicles B.5 Noise emissions from Noise pressure level in dB(A) near noise Site & approach Daily during site HSE Supervisor vehicles and machinery sources (5m) road preparation
B.6 Supervision of material Number of vehicles reported with overloaded Site Daily during site HSE Supervisor with Vehicular / transport material / uncovered material preparation Civil Contractors
B.7 Accident reporting Number of casualties / Number of fatalities Site & Haul During life cycle of HSE Supervisor Routes project
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Environmental EPI Performance Indicator Monitoring Parameter Location Period & Frequency Responsibility No. (EPI) B.8 Fugitive emission of dust Visual observation of dust in air by haziness Near stockpiles Daily during the entire HSE Supervisor during material handling and and storages project life-cycle storage C Drilling & Testing C.1 Gaseous pollutant emissions Pollutant concentrations in gaseous DG Stack Monthly during drilling & HSE Supervisor through Drilling from DG Set emissions and maintenance parameters (air, testing contractor fuel filters & air-fuel ratio) of DG sets influencing air emissions Daily during drilling & testing Visual observation of exhaust smoke characteristics 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 Site As and when spills occur HSE Supervisor through Drilling Spill / Characterization of Spilled Substances contractor for Contaminants (Heavy Metals, Toxics, etc.) C.6 Fugitive emission of cement Visual observation of cement dust in air by Near stockpiles Daily during the entire HSE Supervisor dust during handling and haziness and storages project life-cycle storage
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Environmental EPI Performance Indicator Monitoring Parameter Location Period & Frequency Responsibility No. (EPI) C.7 Runoff from temporary Supervision of functioning of conduits / Site Fortnightly during HSE Supervisor storage areas drains, channels drilling 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 occurs contractor based on emission factors C.9 Waste water quantity & Volume estimate At discharge Weekly during drilling HSE Supervisor through Drilling quality (Process water viz. rig point contractor wash, 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 Total volume generated At storage Once during drilling HSE Supervisor through Drilling disposal location period contractor Concentration of hazardous constituents as per Hazardous Waste Management and Handling 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 & Once per site HSE Supervisor through Drilling & Approach road Civil contractor
D.2 Air emissions from vehicles PM10, PM2.5, NOx, SO2, CO, HC based on Exhausts Once in project lifecycle HSE Supervisor through emission factors Daily Vehicle/Civil contractor Visual observation of emissions (black signifying more pollution)
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Environmental EPI Performance Indicator Monitoring Parameter Location Period & Frequency Responsibility No. (EPI) D.3 Fugitive emission of dust Visual observation of dust in air by haziness Near stockpiles Daily during the entire HSE Supervisor during transport of drilling and storages activity facilities D.4 Site restoration Visual observation of : Site Daily during Civil Supervisor with HSE Clearing of decommissioning waste decommissioning Supervisor Leveling of site Relaying of top soil Regeneration of top soil
B) Environmental Quality Monitoring
EQI Environmental Quality Monitoring Parameter Location Period & Frequency Responsibility No Indicator (EQI) A Approach Road & Site Development A1 Soil Fertility Fertility parameters like pH, NPK ratio, Site & adjacent areas Once before site HSE Supervisor Total Carbon, etc. preparation A2 Quality of water Analysis of Parameters as per CPCB Use- Natural drainage channel Monthly during site and HSE Supervisor class receiving run-off road works discharges
A4 Ambient Air Quality Measurement of PM10, PM2.5, NOx, SO2, At Surrounding receptor Monthly during site and HSE Supervisor CO, HC using ambient air sampler points road works A5 Ambient noise quality Hearing / perception At surrounding receptor Daily site and road HSE Supervisor Measurement of Noise Pressure Level in points works dB(A) Monthly site and road works
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EQI Environmental Quality Monitoring Parameter Location Period & Frequency Responsibility No Indicator (EQI) 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, At Surrounding receptor Monthly during drilling HSE Supervisor CO, HC , using ambient air sampler points and testing B2 Ambient noise quality Hearing / perception At surrounding receptor Daily during drilling and HSE Supervisor Measurement of Noise Pressure Level in points testing dB(A) Monthly during drilling and testing B3 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 B4 Quality of water Analysis of Parameters as per CPCB Use- Natural drainage channel Monthly during drilling HSE Supervisor class receiving run-off & testing discharges C Decommissioning / Closure C1 Ambient noise quality Hearing / perception At surrounding receptor Daily during HSE Supervisor Measurement of Noise Pressure Level in points decommissioning dB(A) Monthly during decommissioning C2 Quality of water Analysis of Parameters as per CPCB Use- Natural drainage channel Once after HSE Supervisor class receiving run-off decommissioning discharges
C3 Ambient Air Quality Measurement of PM10, PM2.5, NOx, SO2, At Surrounding receptor Monthly during HSE Supervisor CO, HC , using ambient air sampler points decommissioning C4 Soil Fertility Fertility parameters like pH, NPK ratio, Site & adjacent areas Once after site HSE Supervisor Total Carbon, etc. restoration
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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 ten 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, ONGC, Oil India in Assam, Geopetrol in Andhra Pradesh, Eni India in Andaman Sea, ONGC in Mizoram, Cairn Energy in Rajasthan and Gujarat, British Petroleum in West Bengal etc. SENES India was responsible for carrying out the EIA / EMP report for EIA Studies for Pre- NELP Block AA-ONJ/2 (for Drilling 9 Exploratory Wells). 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 Debabrata Ghosh: 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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