Stormwater Best Management Practices: Outdoor Washing
Outdoor washing operations, such as machine or equipment washing or hosing paved areas, results in the generation of wash water that can contain or pickup pollutants. These pollutants can be carried to the Charles River via the storm drains. This dirty wash water should be discharged to the sanitary sewer system, not the storm sewer system.
To minimize stormwater pollution from outdoor washing activities, you can do the following:
- Equipment should be washed indoors whenever possible.
- If outdoor washing is unavoidable, use environmentally safe cleaning solutions.
- Never dump buckets of dirty water outdoors or into storm drains and catch basins.
Some alternatives for washing large equipment, such as trucks, shopping carts, steel racks, etc., that must be washed outside are:
- Commercial Car/Truck Wash. Have vehicles washed off-site at a commercial or industrial truck wash facility. Ensure that this washing facility discharges its washwater to the MWRA system and not the storm sewer system.
- On-site Washing Service. Use a truck washing service that provides the customer with vehicle washing service at the facility site. Ensure that the Service Company uses a portable system to collect the dirty washwater. This type of service could also be used to wash other large equipment. The Service Company must collect the washwater and transport it by vacuum truck to a permitted facility.
- Washing On Grassy Surfaces. Wash equipment and vehicles on a grass or other pervious surface, such as gravel or dirt using environmentally safe cleaning solutions. In this case the runoff drains to the ground and does not runoff into the storm sewer system or Charles River.
