When you pressure wash, pollutants and suspended solids can enter storm drains or ditches that lead to our streams, lakes, and Bellingham Bay. Pressure washing should be avoided as much as possible. Only pressure wash if you are able to capture and properly dispose of all wash water.
When water from pressure washing enters the storm system, a water quality violation occurs. Instead, direct wastewater to landscaped areas where the water will have time to infiltrate and break down in the soil. Use a sump pump to redirect wastewater from the storm system into the sanitary sewer or use a wet vacuum to catch wastewater before it reaches the storm system. Call the City of Bellingham Stormwater Hotline at (360) 778-7979 to check out a sump pump kit.
Soap or chemical cleaners may not be necessary for a thorough cleaning.
Often water pressure is enough to remove dirt and grime. If you must use a
cleaner, make a less toxic version like the following:
• 2 cups mild, phosphorous-free laundry detergent
• 1/2 cup vinegar
• 1/4 cup lemon juice
When pressure washing roofs with chemicals for moss removal, make sure the chemicals do not enter the storm system. Redirect downspouts to vegetated areas or temporarily block the downspouts entirely and collect the water for proper disposal in the sanitary sewer. Reconnect your downspouts when you are finished washing.
Make a plan to keep pollutants, such as chemical cleaners and paint (that may contain lead) out of the storm system. When you are finished washing, follow the Disposal of Toxics Guidelines (PDF) for proper storage and disposal.