Valdez Construction 6/12/2023 - Laserfiche WebLink

City of Everett 01 57 00-4 Inductive Charging Infrastructure for Everett Transit E. If Work is suspended for an extended period of time,the Contractor shall be responsible for controlling erosion, pollution, sedimentation, and runoff during the shutdown period. F. In addition to other requirements in the Contract, this temporary work shall include, but is not limited to, the following water quality considerations: 1. DIVERSION OF STORM WATER: Storm water shall be diverted around the Project to prevent erosion. This may be accomplished by pumping; improvising ditches; lining channels or by placing metal, plastic or concrete gravity pipe; constructing ditches, berms, Culverts, etc.,to control surface water; or constructing dams, settling basins, or energy dissipaters to control down stream flows. 2. INTERCEPTING GROUND WATER: Ground water encountered during construction shall be intercepted and routed around the construction site to prevent erosion by the use of gravel trenches, French drain tiles, well points, or interceptor ditch. The Contractor shall provide means of controlling underground water that may be encountered during the Work. See WAC 173-200. 3. TURBID WATER TREATMENT BEFORE DISCHARGE: Determination of turbidity in surface waters shall be at the discretion of the Owner; for Lake Class Receiving Waters, turbidity shall not exceed 5 NTU (Nephelometric Turbidity Units)over background conditions;for Class AA and Class A Waters,turbidity shall not exceed 5 NTU over background turbidity when the background turbidity is 50 NTUor less, or have more than a 10 percent increase in turbidity when the backgroundturbidity is more than 50 NTU. See WAC 173-201A a. The term turbidity means the optical property of sample demonstrating the scattering and absorption of light caused by suspended material as expressed in Nephelometric Turbidity Units and measured with a calibrated turbidimeter. b. Discharges to a State waterway caused by aggregate washing, drainage from aggregate pit sites, and stockpiles or dewatering of pits and excavations shall not increase the existing turbidity of the receiving waters. c. Turbid water from the Project Site shall be treated as required by WAC 173- 201A before being discharged into stream or other State waters. Turbidity may be removed by the use of lagoons or holding ponds, settling basins, overflow weir, polymer water treatment, discharging to ground surface, by percolation, evaporation or by passing through gravel, sand or fiber filters. 4. TEMPORARY EROSION CONTROL: Temporary erosion control shall be exercised by minimizing exposed areas and slopes until permanent measures are effective. Plastic sheet covering shall be placed over exposed ground areas to protect from rain erosion. Other alternative methods for erosion control under certain situations may include netting, mulching with binder, and seeding. Should rutting and erosion occur the Contractor shall be responsible for restoring damaged areas and for cleanup of eroded material including that in ditches, catch basins, manholes, and Culverts and other pipes. 5. CHLORINE RESIDUAL: Water containing chlorine residual shall not be discharged directly into Storm Drains, streams, or State waters. Chlorine water may be discharged into sanitary sewers or disposed on land for percolation. Chlorine residual may be reduced chemically with a reducing agent such as sodium thiosulphate or vitamin C. Water shall be periodically tested for chlorine residual. 6. VEHICLE AND EQUIPMENT WASHING: Water used for washing vehicles and Equipment shall not be allowed to enter Storm Drains, streams or other State waters unless separation of petroleum products, fresh concrete products or other 01 57 00 -4 TEMPORARY CONTROLS