Pressure washing is a method often used to clean buildings and paved surfaces. If not done correctly, pressure washing can harm water quality.
Pressure washing can release pollutants from surfaces due to the strong force of the water. This resulting wastewater may contain toxic substances like oils, grease, metals and dirt. If not properly contained and disposed of, this wastewater can enter storm drains, which often flow directly into our local creeks or Bellingham Bay with little to no pollution treatment. Proper containment and cleanup are crucial to protect our waterways.
Discharge of anything other than rain into the storm drain, including pressure wash wastewater, is prohibited by Bellingham Municipal Code 15.42, as well as State and Federal laws. Thankfully, there are easy steps and accessible tools to help businesses manage pressure wash water runoff.
Do you need help containing, capturing, and properly disposing of wastewater generated from pressure washing? We can help! Contact us to borrow a free pressure washing kit. The kit includes a shop vacuum with pump, spill barrier, catch basin cover, extension cord, safety cones, hose and sandbags (optional).
These kits are available to borrow for businesses, property managers, charitable car washes, churches, schools, etc.
How it Works
- Request a kit: Contact us at bppa@cob.org or 360-778-7740.
- Site visit: We will contact you to set up a site visit to identify storm drains and wash area.
- Kit demonstration: We’ll show you how the kit works and offer site-specific suggestions.
- Rental agreement: Sign the rental agreement form.
- Kit use: Use the kit as per the agreed protocols during your rental period.
- Return the kit: Ensure the kit is clean and dry before returning it.
When you pressure wash, you must capture and collect all wastewater runoff and dispose of it in a drain that leads to the sanitary sewer (not a stormwater drain), or direct it to a vegetated area to soak into the ground if there are no alternative options.
Before pressure washing, use dry methods such as brooms or blowers to clean the work area. Block off storm drains to prevent polluted wash water from entering. Then capture the wash water using a containment system by following the steps below:
- Set up a containment system:
- Equipment needed:
- Storm drain grate covers
- Ground cover tarps
- Portable pump and hoses
- Portable ground berm
- Sandbags
- Absorbent pads and socks/boom
- Equipment needed:
- Identify where wash water will flow and temporarily cover the storm drain grate:
- For ground surfaces, use a pressure washer with a built-in water reclamation system.
- For equipment and vehicles, line the area with a ground tarp and surround it with a temporary berm.
- Find additional tips for washing vehicles.
- Capture the wash water:
- While washing, move or adjust the containment system to capture and contain the wash water.
- Watch this YouTube video to learn how to use a DIY wash water system.
- Dispose the wash water properly:
- When washing is complete, or wash water runs the risk of overflowing into a storm drain, collect the dirty water by using the pump and hose.
- Wastewater should only be disposed of in a sanitary sewer or an area with natural vegetation, as long as it doesn’t saturate and overflow.
- Wash water that contains solid waste and petroleum products must be filtered prior to disposal.
PCBs, or polychlorinated biphenyls, are carcinogenic chemicals used as additives in paints and cements. Buildings built or renovated from about 1950 to 1979 had widespread use of PCBs.
Wastewater from buildings suspected of using PCBs cannot be disposed of in the storm drain and may have to be disposed of as hazardous waste.
PCBs may be present in caulking, grout, joint materials, paints, sealants, lubricants, roofing, metal coatings, and light ballasts.
For more information on PCB’s and their threat to water health and human health, visit Washington State of Ecology’s PCB webpage.
Pressure washing can create hazardous waste that needs special disposal. This includes items like dirty absorbent materials that may contain PCBs, rags or absorbent pads with gasoline, oils, grease, thinner, solvent, or organic chemicals.
Dispose of hazardous waste properly:
- Option 1: Use a licensed waste hauler.
- Option 2: Bring small quantities of accepted waste to a hazardous waste drop-off location. Find a drop-off location.
Keep records of your hazardous waste disposal: who hauled it, how much was hauled, and when it was hauled.
More Information for Businesses
Our Pollution Prevention Specialists are here to help businesses manage wastewater and utilize available resources. Unsure how to use these tools or properly collect and dispose of pressure wash water? Contact our Business Pollution Prevention Program for a free training and additional resources at bppa@cob.org or 360-778-7740.
For business-related stormwater resources, trainings and more, visit the Washington Stormwater Center.
