What Power Washing Is
Power washing is any activity that uses a water pressure system, including steam cleaning, to clean vehicles, equipment, sidewalks, buildings, dumpsters, or other impervious surfaces. In addition to water, detergents, degreasers and other products may be used in commercial power washing.
The Problem With Power Washing
Did you know that storm drains are not connected to sanitary sewer systems or treatment plants? The primary purpose of storm drains is to carry rainwater away from developed areas to prevent flooding. Wash water from power washing activities may contain significant quantities of oil, grease, chemicals, dirt, and detergents that could end-up in our creeks, rivers, lakes, and the ocean. Disposing of these materials into storm drains causes serious ecological problems — and is prohibited by law.
Best Management Practices
Best Management Practices, or BMPs, are procedures that help to prevent pollutants from entering our storm drains. Each of us can do our part to keep storm water clean. Using BMPs adds up to a pollution solution!
Use Dry Clean-up Methods
- Instead of pressure washing, determine what alternative dry methods are available.
- Use mops, brooms, rags or wire brushes to clean pavement, buildings and equipment as much as possible.
- Use vacuums or other machines to remove and collect loose debris before applying water.
Location, Location, Location
- Prior to a washing, block all storm drains with an impervious barrier such as gravel bags or berms, or seal private storm drains with plugs or rubber mats. Make sure this practice does not flood the area or adversely affect vehicle or pedestrian traffic.
- Never dispose of wash water into the street, storm drains, landscape drains, drainage ditches or streams.
- Wash vehicles and equipment on grassy or gravel areas so that the wash water can seep into the ground.
- Create a containment area with berms and tarps or take advantage of low ground to keep wash water contained.
- Check that the wash water is not leaking through and add more berms or barriers if necessary to contain the wash water.
Just Enough for the Job
- Minimize water use by using high pressure, low-volume nozzles.
- Use the minimal amount and least toxic detergents and degreasers you will need to complete the job. Try phosphate-free detergents.
- Use a mop or rags to clean heavily soiled areas before power washing.
Only Rain Down the Storm Drain
- Do not wash equipment or vehicles outdoors on saturated ground or on days when rain is probable.
- Pump or vacuum up all wash water in the contained area.
- With the property owner's permission, pump or pour the wash water to landscaped areas that will not run off to a storm drain; or drain it to the sanitary sewer through an interior building drain, sink, or private sewer clean-out. Discharges to the sewer should not contain hazardous materials, grease, grit, or any material that could clog piping.
- Sediments and other solids remaining on the ground should be swept or vacuumed-up immediately so they don't wash into the storm drain system.
A Word About "Biodegradable" Soaps
"Biodegradable" is a popular marketing term that can be misleading. Just because a product is labeled as biodegradable doesn't mean that it is non-toxic. Some products are more toxic than others, but none are harmless to aquatic life. Soapy water entering the storm drain system can have a negative impact on fish and other wildlife within hours.