A Contractor’s Responsibility To Be In Compliance
Most power washing activities are conducted outside. This often results in the discharge of wastewater to the storm drain, unless the equipment operator takes steps to collect and dispose of it legally. Discharge of power washing wastewater to the storm drain is prohibited because it contains pollutants from the objects or surfaces being cleaned and/or from the cleaning compounds being used. Even cleaners labeled “biodegradable” and “non-toxic” may be harmful to aquatic life, especially after cleaning various surfaces (e.g. dumpster areas, parking lots, equipment and more) that contain fats, oils, greases, chemicals (such as herbicides, insecticides, pesticides, solvents, anti-freeze and fertilizers), as well as other substances.
• Power washing wastewater that enters storm drains flows directly into lakes, rivers, and streams. This water is not treated or cleaned to remove pollutants. Pollutants discharged to the storm drain harm fish and wildlife and contaminate recreational sites and drinking water supplies.
The discharge of wastewater from power washing to the storm drain or surface waters is prohibited by law. If you provide power washing services or are considering hiring a power washer make sure your service adheres to these regulation.
However, preventing discharge to the storm drain is only part of the story. Improper discharges to the sanitary sewer, septic tanks, or land can also cause environmental harm, damage equipment and facilities, and violate regulations
Power Washing as Part of the Solution
Power washing is an activity that can help improve the quality of our waters when done properly. By cleaning (power washing) surfaces (e.g. equipment, parking lots, sidewalks, buildings, etc.), collecting the wastes (water and/or debris), and properly disposing of the wastes, there is less chance of pollutants ending up in our waterways. It is through education, proper collection and disposal that pressure washing can have a positive impact on the environment!
BEST MANAGEMENT PRACTICES
Planning
The recovery of wastewater from power washing is not difficult and is being practiced by many contractors. Modern wastewater recovery systems are small enough to be installed in trailers that are 18′ to 20′ long and they fit easily inside low ceiling parking structures.
Surface Pre-Cleaning
Consider using dry methods for surface pre-cleaning, such as using absorbents on small oil spots and sweeping up trash/debris/dirt/used absorbent before wet washing. Methods such as these may be used at locations such as auto repair facilities; auto parts stores, gas stations, as well as many other places. In most cases, absorbent material (e.g. kitty litter) used to pre-clean oil spots and has not become saturated may be discarded as a non-hazardous waste in the garbage receptacle. However, you should also be aware of the costs and requirements associated with disposing of pre-cleaning wastes which may be identified as hazardous waste and require special management. Note: it is important to remember, when using dry pre-cleaning methods, be sure to pick up pre-cleaning debris as soon as possible, so the materials do not have a chance to enter the storm drains.
Power Washing
Wastewater Collection
Once wastewater has been collected and/or discharged to the sanitary sewer system, visible solids remaining in the collection area must be swept up to prevent subsequent discharge to the storm drain.
Storm Drain Covers/Mats – These devices are placed on top of the storm drain cover grate, creating a quick seal, thus preventing wastewater from entering the storm drain system. Storm drain covers/mats (magnetic vinyl mats, PVC drain covers, polyurethane mats, and others) allow wastewater to accumulate on top of it until the pressure washing activity is complete and the wastewater can be collected for proper disposal. Storm drain covers/mats are frequently used along with a vacuum device (e.g. sump pump, wet/dry vacuum, and vacuum pump).
Containment Pools – A portable or temporary containment pool is another option which may be used by pressure washers to collect wastewater. Containment pools are easy to assemble, provide an immediate work area, and allow the wastewater to be collected in a manner that will prevent pollutants from entering the storm drains. Containment pools vary in size and material, and hold anything from a shopping cart to a truck and trailer.
Vacuums/Pumps – Devices such as wet/dry vacuums, sump pumps, and vacuum pumps may be used to collect wastewater after pressure washing. Vacuum devices typically have an extension (vacuum boom) which allows the wastewater to be collected efficiently. In addition, many vacuum devices are designed with a second hose (e.g. garden hose) that can run from the pump to the sanitary sewer or a truck/trailer mounted holding tank, depending on disposal method.
Wastewater Disposal