Table 11 - 2 in Saidabad Water Treatment Plant Project, Phase III

Table 11-2: Environmental impact during operation phase and mitigation measures (Original Table 43) Activity/Issu esPotential ImpactsProposed Mitigation and Enhancement MeasuresResponsib le PartiesPumping operation at the Water intakeScreening waste accumulati on› Screening waste needs to be removed regularly from the coarse screens. Local labour may be employed for such operations.DWASA› Waste should be stored in a designated Waste Storage Area.› Proper disposal of screening wastes, floating debris (to be treated as a solid waste) by available Sonargaon Municipal Solid Waste Management System: formulate disposal management plan and provide adequate facilities to carry it outAccidental Spillage of fuel (to run generators)› Forbid discharge of fuel, lubricants, chemicals, and wastes into surface waters or on land.› Adopt proper disposal techniques for any hazardous waste: hazardous waste management plan and provide adequate facilities to carry it outNoise Pollution› Plant noise will be maintained following the National Noise Pollution (Control) Rules -2006.› Permissible noise levels inside buildings during operation: The following limits specified as NR rating curves shall not be exceeded with the relevant roomor building in its normal mode of operation and shall hence generally apply with windows and doors shut, and with air-conditioning / ventilation plant in operation. The Contractor shall therefore pay due attention in its design to noise contributed by operation of the facilities outside the room, the noise arising from the air-conditioning/ventilation of the room, and any noise generated by equipment positioned in the room.› Permissible noise levels inside buildings during operation: The noise levels experienced by personnel moving about on the site at any point at grade level, and on various buildings, platforms, galleries, plant items and access ways, shall not exceed the following or the respective figures provided in the applicable Laws, whichever one is lower.Public Health and Safety› Take measures to avoid or minimize transmission of communicable diseases that may be associated with the influx of temporary or permanent project labor› Implement measures and actions to control the safety of deliveries of hazardous materials, and of storage, transportation and disposal of hazardous materials and wastes› Implement measures to avoid or control community exposure to the hazardous material› Emergency Response plan of DWASA will include the public evacuation procedures.Presence of silt, oil and grease in raw water› Design of intake structure in order not to collect water from the surface to avoid oil and grease.› Design of intake structure in order to avoid collecting water very close to the riverbed to prevent excess silt from entering.› Facilities at intake for removing silt, oil and grease entering accidentally the system› Keeping a provision in the intake system to collect water from different depths depending on the water level of Meghna RiverOperationa l staff movement (impact on traffic)› Operational staff movements will be monitored by implementing good industry practices during operation phase› Although minimum impact is anticipated, working hours to be adjusted in a way to avoid school hours, and spread across the shifts of the staff during operation.Riverbank stability› The riverbank stability risk of the intake site is mitigated through "design and build" works specifications for the intake site.› Foundations for the Intake structure and transfer pipes shall be designed to protect against annual changes in riverbed level and the anticipated maximum riverbed scour when the river is at Maximum Flood Level.› The Contractor shall conduct monthly bathymetric surveys of the riverbed level over at least a 100m radius around the centre of the Intake structure to monitor changes in bed level during construction.› The Contractor shall also carry out physical modelling of river flow around and inside the Intake using an independent organisation specialising in hydraulic modelling. The design of the Intake structure and all underwater structures, including scour protection measures, shall be based on the results of the modelling.› The Contractor shall provide river training works and scour protection to protect the structures and the riverbank from scour with the river flowing at the Maximum Flood Level.Treatment plant operation and Sludge Treatment FacilitiesAccidental Spills and leaks oil, toxic chemicals› Good house keepingDWASA› Proper handling of lubricating oil and fuel› Collection, proper treatment, and disposal of spills.› Formulate an accident management planGeneration of sludge dry cakes after sludge dewatering operation› Assessment of characteristics of sludge through Toxicity characteristic leaching procedure (TCLP) test to confirm that the material is not hazardous› Exploring beneficial options for dewatered sludge disposal (e.g. land application, co-disposal with sewage sludge, selling to brick factory)› If beneficial options are not available, consider landfilling in a suitable land/location.› If lands are not available, make arrangements with Dhaka South City Corporation to dispose the sludge dry cakes in one of their designated landfills.Noise Pollution› Plant noise will be maintained following the National Noise Pollution (Control) Rules -2006.Sludge Transport› The nearest sanitary landfill site has been selected to minimise transport distance; Matuail is only 4km from the site and the DSCC long term development plan includes for a direct road route.› The contractor is incentivised to provide plant that produces sludge cake with a high dry solids content as this will reduce their O&M costs through fewer vehicle movements.› It has been recommended to DWASA that an alternative sludge disposal route is investigated which would involve pumping the sludge to Dasherkandi sewage treatment works.Generation of liquid residuals after sludge dewatering operation› Direct disposal to nearby lowlands if the residuals meet the effluent discharge criteria as per ECR 1997 (see Annex)› If discharge criteria are not met, return to the head end of the plant for treatment. Must not be discharged to the head end as a pulse, rather metered in at a flow rate compatible with the hydraulic loading of the plant preferably during diurnal high flows.Poor raw water quality in the Meghna River› Seeking the help of the Department of Environment (DoE) for preventing discharge of untreated industrial and domestic wastewater into Meghna River and thereby ensuring its water quality. Also, it is recommended to restrict development activities both upstream and downstream of the intake point, especially those activities that could affect the water quality and hydrology at the intake location.DWASA and DoE› The project objective is to reduce (a) ground water abstraction and (b) replace polluted Sitalakhya River water with Meghna River. Additional wastewater due to population growth within Saidabad Phase-I and II supply zones are currently being treated by Dasherkandi Sewage Treatment Plant and the proposed expansion of Saidabad Phase-III distribution network will be treated by upgrading Pagla Sewage Treatment Plant under Dhaka Sanitation Improvement Project (WB). Therefore, conventional wastewater treatment process will be in place to treat and dispose of water production from all three phases of Saidabad project.Site security issues during operation› No special security personnel is envisaged during the operation phase; security features has been addressed in design specifications. EIB’s International human rights standards and principles include (i) the UN Basic Principles on the Use of Force and Firearms by Law Enforcement Officials, (ii) the UN Code of Conduct for Law Enforcement Officials, (iii) the Voluntary Principles on Security and Human Rights and (iv) the International Code of Conduct on Private Security Providers will be followed if security personnel is employed.DWASA