1710 W MARINE VIEW DR 2024-01-03

Location and Placement . Locate concrete washout areas at least 50 feet from sensitive areas such as storm drains, open ditches, water bodies, or wetlands. . Allow convenient access to the concrete washout area for concrete trucks, preferably near the area where the concrete is being poured. . If trucks need to leave a paved area to access the concrete washout area, prevent track -out with a pad of rock or quarry spalls (see BMP C 105: Stabilized Construction Access). These areas should be far enough away from other construction traffic to reduce the likelihood of acci- dental damage and spills. . The number of concrete washout areas you install should depend on the expected demand for storage capacity. . On large sites with extensive concrete work, concrete washout areas should be placed in mul- tiple locations for ease of use by concrete truck drivers. Concrete Truck Washout Procedures Washout of concrete truck drums shall be performed in designated concrete washout areas only. Concrete washout from concrete pumper bins can be washed into concrete pumper trucks and discharged into designated concrete washout areas or properly disposed of off -site. Concrete Washout Area Installation . Concrete washout areas should be constructed as shown in the figures below, with a recom- mended minimum length and minimum width of 10 ft, but with sufficient quantity and volume to contain all liquid and concrete waste generated by washout operations. . Plastic lining material should be a minimum of 10 mil polyethylene sheeting and should be free of holes, tears, or other defects that compromise the impermeability of the material. . Lath and flagging should be commercial type. . Liner seams shall be installed in accordance with manufacturers' recommendations. . Soil base shall be prepared free of rocks or other debris that may cause tears or holes in the plastic lining material. Maintenance Standards Inspection and Maintenance • Inspect and verify that concrete washout areas are in place prior to the commencement of con- crete work. . Once concrete wastes are washed into the designated washout area and allowed to harden, 2019 Stormwater Management Manual for Western Washington Volume /I - Chapter 3 - Page 322