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EXHIBIT A Reservoir Inspection,Cleaning& Repair Bid#OSD 2021-604 5"Disposal of Sediments."Following waste profiling,all filter bags and sediment shall be properly packaged, labeled, and removed from the site by the Contractor. 1) Dichlorination, Disposal of Water a) Two weeks prior to mobilizing any equipment and material on-site, the Contractor shall provide a comprehensive plan for dichlorination and sediment filtration. The Contractor's plan shall specify exactly what equipment they are planning on using during the cleaning, and the estimated discharge pump flowrates, if pumps are used. Contractor is responsible for demonstrating that the capacity of the storm drains or other drainage system is not exceeded. b) The plan should indicate exactly how the discharge will be dechlorinated. If an in-line system will be used, the capacity of the system needs to be disclosed, and the estimates or calculations for the flow rate and dichlorination agents submitted to the City for review. c) The Contractor should anticipate a range of chlorine residual between 0.5 to 2.5 parts per million (ppm or mg/I.) in the storage facilities. Contractor shall stock sufficient dichlorination tablets, granules, or powder for dichlorination. d) The spray down solution used for disinfection shall be contained and dechlorinated prior to discharge. e) Contractor shall monitor for dichlorination and shall measure the total chlorine residual with a Hach 890 (or equivalent) every 15 minutes at the beginning of the day and every hour thereafter, at the discharge point(s). f) Contractor shall document its dichlorination monitoring and provide to the City dichlorination log sheets at the end of the project. Daily log sheets shall be kept on site and available for City inspection daily. g) Contractor shall monitor discharge flow rates in outfall structure and daylight discharge pipe as shown on the project drawings. At no time shall the discharge flow rate be so great as to cause the outfall structure to overflow or soil erosion to occur at or around the outfall of the discharge pipe. h) At any time, if the City determines the dichlorination and disposal of water plan is not functioning according to the submittal and discharge limitations,the Contractor shall immediately implement measures, which may include reduction of or temporary suspension of discharge of water or temporary suspension of cleaning operations, to bring the disposal plan back in conformance at no additional cost to the City. 2) Filtration and Sediment Management a) The Contractor shall submit a detailed description of methodology of dechlorinating and filtering sediments from discharge water and the plan shall be approved by the City prior to commencement of work. The Contractor shall have available materials to create a temporary holding lagoon in the event run off needs to be controlled or directed to a specific point of drainage. b) The Contractor shall be responsible for ensuring that no sediment in excess of local applicable discharge regulations be discharged from the site during the cleaning. The contractor shall use available Best Management Practices (BMPs) including but not limited to, Baker-type storage tanks, rock or gravel socks, sandbags, non-woven geosynthetic material filter bags, hay bales and filter bags, to ensure that sediment is removed prior to discharge. c) Contractor shall monitor turbidity and pH. Turbidity and pH shall be measured every 15 minutes at the beginning of the day and every hour thereafter,at the discharge point(s)post-BMPs. Rate Sheet Page 3 of 8