Environmental Screening Report for the Augmentation of Dunumadalawa Water Treatment Plant Project Management Unit Strategic Cities Development Project November 2015 Table of Contents 1. Project Identification 03 2. Project Location 03 3. Project Justification 08 4. Project Description 08 5. Description of the Existing Environment 13 6. Public Consultation 17 7. Environmental Effects and Mitigation Measures 19 7a. Screening for Potential Environmental Impacts 19 7b. Environmental Management Plan 23 8. Cost of Mitigation 61 9. Conclusion and Screening Decision 62 10. EMP Implementation responsibilities and Costs 64 11. Screening Decision Recommendation 64 12. Details of Persons Responsible for the Environmental Screening 64 Annexes 1. Site layout Plan of the Dunumadalawa WTP 2. Geological and Soil Map of the Project Area 3. Environmental Sensitive Area Map of Kandy 4. Summary of Procedure to Obtain Mining License for Borrow Pit Operation 5. Summary of Procedure to Obtain Mining License for Quarry Operation 6. Chance Find Procedures 7. Sri Lankan Environmental Pollution Control Standards 8. Waste Management General Guidelines 9. Factory Ordinance and ILO Guidelines 10. Detailed Designs Abbreviations CEA - Central Environment Authority DS - Divisional Secretariat PMU - Project Management Unit RDA - Road Development Authority GSMB - Geological Survey and Mines Bureau NWS&DB - National Water Supply and Drainage Board SLT - Sri Lanka Telecom CEB - Ceylon Electricity Board ICTAD - Institute for Construction Training and Development ID - Irrigation Department LA - Local Authority ILO - International Labor Organization IDA - International Development Agency WB - World Bank PS - Pradeshiya Sabha IE - Irrigation Engineer ME - Mining Engineer MOH - Medical Officer of Health PHI - Public Health Inspector RoW - Right of Way EIA - Environmental Impact Assessment IEE - Initial Environmental Examination RHS - Right Hand Side LHS - Left Hand Side Co-op - Co-opeartive DBH - Diameter at Brest Height IML - Industrial Mining License EPL - Environmental Protection License VET - Vehicular Emission Test EMP - Environmental Management Plan EA - Environmental Assessment AL – Artisinal Mining License Strategic Cities Development Project Environmental Screening Report 1. Project Identification Project title Strategic Cities Development Project Augmentation of Dunumadalawa Water Treatment Plant Project Proponent Strategic Cities Development Project, Ministry of Megapolis and Western Development 2.Project Location Location Dunumadalawa Water Treatment Plant is located about 0.7 km away (relative to the nearest from the Kandy City Center in the Central Province of Sri Lanka. The town, highway) proposed project area is a water supply scheme connected to the Dunumadalawa tank located in the Kandy district. This tank and the water supply scheme was built by the former British rulers (1870s) in order to provide clean drinking water to residents in the Kandy city. Dunumadalawa and Rosnith tanks are interconnected together through a system like cascade to collect water and supply to downstream people in the Dunumadalawa and surrounding areas. Location of the project is depicted in Annex 1. Definition of Project Area Geographical co-ordinates of the Dunumadalawa Water Treatment Plant are E-80.63759 and N- 7.284540 and located at an elevation of 550 m MSL. (The geographical extent Dunumadalawa and villages surrounding belongs to GangawataKorale of the project & areas Divisional Secretary Division (DSD) of the Kandy district. The local affected during administrative bodyof the project area is the Kandy Municipal Council construction) (KMC). The area affected during construction due to the construction of the proposed augmentation of the water treatment plant will be limited mainly to the existing water treatment plant.Impacts foreseen will be at a very low magnitude as it is to construction of new aerator and floculator. These new construction will be done between existing water intake and the treatment plant building just behind the Dunumadalawa Dam. See attached Project Area Map in Annex 1. Strategic Cities Development Project/MM&WD Page 4 Adjacent land and features Fig 1: Dam of the Dunumadalawa reservoir Eastern boundary of the existing water treatment plant is Dunumadalawa Dam (Fig. 1) and Northern boundary is the existing water meter laboratory of the KMC and the outlet canal of the Dunumadalawa reservoir (See Annexure 1). Western Boundary of the existing water treatment plant is Reservoir tank 2 (Fig. 2) of the Dunumadalawa water supply scheme. Fig 2: R2 Reservoir Tank 3. Project Justification Need for the project Dunumadalawa Water Treatment Plant is a fully gravity water supply scheme operates as a partial treatment plant having its original design (What problem is the project capacity of 1,500 m3/day. As mentioned above,it was built in year 1975 to going to solve) provide safe drinking water facility to Kandy City and raw water is obtained from Dunumadalawa Reservoir. At present, it was identified that the raw water from Dunumadalawa reservoir contains high concentration of iron and colour which exceed permissible levels in accordance with the SLS-1983. Further it was noted that most of the period, pH levels of raw water have been dropped beyond the acceptable limits. In addition, it has been recorded that higher levels of Turbidity during the rainy period and this situation will be aggravated in near future as the drinking water source Strategic Cities Development Project/MM&WD Page 5 has been exposed to the pollution sources on the grounds in the upper catchment area. The present treatment process taking place to treat the water is conventional process but without aeration and flocculation steps. In addition Kandy Municipal Council assumes that they extract 2000m3/day of water through the existing Dunumadalawa water treatment plant but KMC doesn’t have any records to justify that quantity since the treatment plant doesn’t have a bulk flow meter to measure water flow through the WTP. Thus the Kandy Municipal Council proposed to augment the Dunumadalawa water treatment plant up to 5000 m3/day capacity and get its continuous input since the operational and maintenance cost of the plant is very low with compared to the treatment plant located at Gatambe as it is a gravity water supply scheme.However, with respect to the water flow records of Dunumadalawa impounding reservoir, static water head, and availability of the land area for new structures such as aerator and flocculator, and restraint to expand the existing structures such as sedimentation tank, the maximum design capacity of the treatment plant is limited to 3500 m3/day. Purpose of the project The proposed project is to rehabilitate the existing water treatment (what is going to be facility and increase its capacity by 3500 m3/day from its original achieved by carrying out the design capacity of 1500 m3/day to produce reliable and clean project) drinking water which confirms to SLS 614, 1983 and WHO standards. Alternatives considered There were no alternatives to be considered than rehabilitation of (different ways to meet the existing water treatment plant by completing the steps of the project need and achieve the conventional process. project purpose) Alternative methods of disposal of sludge were considered and provision of in situ sludge treatment plant is recommended considering the operational and management issues which could be arisen due to transferring of sludge to Getambe Sludge treatment plant. 4. Project Description Proposed June 2016 start date Proposed September 2017 completion date Estimated LKR 260 Million total cost Present land Proposed intervention sites are owned and maintained by Kandy Municipal Council ownership Description It has been proposed to augment the existing treatment plant by introducing new aerator , of the flocculator and improving five existing filters with new nozzles, chemical dosing system project and plate settlers and convert the current partial conventional process in to complete one (with according to the flow diagram given below. supporting material such as Strategic Cities Development Project/MM&WD Page 6 maps, drawings etc Aeration attached as required) Coagulation & Flocculation Sedimentation Filtration Disinfection Clear Water Storage & Distribution Flow Diagram: Stages of proposed Treatment Process Aeration : Dissolved ferrous and manganese compound Can be oxidized by aeration and precipitated as insoluble ferric and manganic oxide hydrates which then be removed by sedimentation and filtration process. As such, a new aerator is introduced as an addition to the existing structure having its design capacities of 3500 m3 /day and to convert the existing partial water treatment plant in to full treatment plant. Further, Cascade type aerator is proposed here to minimize the head loss within the treatment process (Fig 3&4). Fig. 3: drawing of proposed aerator and floculator Strategic Cities Development Project/MM&WD Page 7 Fig. 4:Site layout plan with Aerator, Floculator and Plate settler Flocculation: New flocculator is introduced for the focculation process as an additional structure to the existing treatment plant. Flocculation in the coagulated water, which causes the fine moving, destabilized particles to come in to contact and become large, readily settleable flocs by improving the creating velocity gradients in the water to increase the chance of collision between particles. The Capacity of the flocculator will be 3500 cum/day. Fig 5: Available