7800 EVERGREEN WAY HYUNDAI O&M Manual 2025-04-28

IV-2 Cleaning or Washing Source Control BMPs S431 BMPs for Washing and Steam Cleaning Vehicles / Equipment / Building Structures Description of Pollutant Sources: Pollutant sources include the commercial cleaning of vehicles, aircraft,vessels, and other transportation, restaurant kitchens, carpets, and industrial equipment, and large buildings with low-or high-pressure water or steam.This includes"charity"car washes at gas stations and commercial parking lots.The cleaning can include hand washing, scrubbing, sand- ing, etc. Washwater from cleaning activities can contain oil and grease, suspended solids, heavy metals, soluble organics, soaps, and detergents that can contaminate stormwater. Permitting Requirements: Obtain all necessary permits for installing, altering, or repairing onsite drainage and side sewers. Restrictions on certain types of discharges may require pretreatment before they enter the sanitary sewer. Pollutant Control Approach: The preferred approach is to cover and/or contain the cleaning activ- ity, or conduct the activity inside a building,to separate the uncontaminated stormwater from the washwater sources. Convey washwater to a sanitary sewer after approval by the local sewer author- ity. Provide temporary storage before proper disposal, or recycling. Under this preferred approach, no discharge to the ground, to a storm drain, or to surface water should occur. The Industrial Stormwater General Permit prohibits the discharge of process wastewater(e.g., vehicle washing wastewater)to ground water or surface water. Stormwater that commingles with process wastewater is considered process wastewater. Facilities not covered under the Industrial Stormwater General Permit that are unable to follow one of the preferred approaches listed above may discharge washwater to the ground only after proper treatment in accordance with Vehicle and Equipment Wash water Discharges Best Management Practices Manual(Ecology, 2012). The quality of any discharge to the ground after proper treatment must comply with Ecology's Ground Water Quality Standards, Chapter 173-200 WAC. Facilities not covered under the Industrial Stormwater General Permit that are unable to comply with one of the preferred approaches and want to discharge to storm sewer, must meet their local storm- water requirements. Local authorities may require treatment prior to discharge. Contact the local Ecology Regional Office to discuss permitting options for discharge of washwater to surface water or to a storm drain after on-site treatment. Applicable Structural Source Control BMPs: Conduct vehicle/equipment washing in one of the following locations: . At a commercial washing facility in which the washing occurs in an enclosure and drains to the sanitary sewer, or 2019 Stormwater Management Manual for Western Washington Volume IV-Chapter 2-Page 505