8920 EVERGREEN WAY THE RESERVE 2025-07-25

CITY OF EVERETT STORMWATER MANAGEMENT MANUAL 4. Wash areas draining to the sanitary sewer shall be covered,or some other method provided,to prevent the entry of significant volumes of rainwater into the separate sanitary sewer system. 5. Any discharge to the sanitary sewer requires the approval of the City's Industrial Pretreatment Program at(425)257-8874. 6. The wash area must be well marked at gas stations,multifamily residences,and any other business where non-employees wash vehicles. 7. For uncovered wash pads,a positive control outlet valve must be provided. This valve may be manually operated,but a pneumatic or electric valve system is preferable. The valve may be on a timer circuit where it is opened upon completion of a wash cycle. The timer would then close the valve after the sump or separator is drained. 4110 Note that the purpose of the valve is to convey only washwater and contaminated stormwater to a treatment system. 8. Phosphate-free biodegradable detergents shall be used when practicable. 9. Recycling of the washwater must be considered. 10. Because soluble/emulsifiable detergents can be used in the wash medium,the selection of soaps and detergents and treatment BMPs should be considered carefully. Oil/water separators are ineffective in removing emulsified or water soluble detergents. 11. At commercial parking lots,where it is not possible to discharge the washwater to a sanitary sewer,a temporary plug or a temporary sump pump can be used at the storm drain to collect the washwater for offsite disposal. 411/ 12. Charity car washes are not allowed to discharge washwater to the City stormwater drainage system. 13. New and used car dealerships may wash vehicles in the parking stalls without soap, or if an approved treatment system for the washwater is in place. At industrial sites,Ecology's Northwest Regional Office must be contacted for NPDES permit requirements even if soaps,detergents,and/or other chemical cleaners are not used in washing trucks. A1.4 Collection and Disposal of Wastewater in Mobile Interior Washing Operations Description of Pollutant Sources: This activity applies to businesses that wash carpets and other interior items on a mobile site-to-site basis. The typical fleet washing process includes use of machines that spray the washwater solution onto the carpet or upholstery and then vacuums the dirty solution up into a portable tank with limited capacity. Pollutants of concern consist of nutrients,suspended solids, organic compounds(such as pesticides and chemicals used for flea and odor control),biochemical oxygen demand(BOD),and chemical oxygen demand(COD). Pollutant Control Approach: Common practice in the past was to discharge the dirty solution onto the ground or to a drain connected to the stormwater drainage system between site visits. These practices are now illegal. Wastewater must be poured into a sanitary sewer drain at the site of collection,the business office,or at another proper location. If discharging to a sanitary sewer,permits must be obtained from the City's Industrial Pretreatment Program at(425)257-8874. If sanitary sewer disposal is not available or not allowed,the collected wastewater must be returned to the business site for process treatment or transfer to a holding tank. Volume IV—Source Control 3-7