New York Sea Grant's
Marina Pollution Prevention Web Site

Section 3: Hauling and Storing Boats - Pressure Washing

Potential Environmental Impacts

When the marine organisms that accumulate on the bottom of a vessel are removed by pressure washing, the water contains fragments of bottom paint and hull materials are often chipped off in the process as well as dissolved constituents from the paint. Copper and zinc in the water can be harmful to some marine animals and plants at concentrations of parts per billion (one drop in 21,000 gallons). These pollutants can get washed into the marina basin. Sediments contaminated with copper can also cause problems and extra expenses related to disposal of materials dredged from the marina basin.

Best Management Practices

Avoid in-water bottom cleaning or hull scraping or any process that occurs underwater to remove antifouling paint from the boat hull. While this is a popular practice for racing sailboats prior to a race to reduce drag, it makes it impossible to capture and treat what's cleaned from the boat bottom.

Pressure wash waste water should not be discharged directly to surface waters or the ground without a permit from your state environmental agency. To the extent possible marina facilities should try to collect the wash water, treat it, and either dispose of it at a sewage treatment plant (through discharge to a sanitary sewer or by hauling using a licensed hauler) or recycle it. Discharge to the sanitary sewer requires local water pollution control authority approval.

Where feasible, wastewater from the washing operation may be collected and reused through a closed loop pressure wash treatment system. For examples of manufacturers of wash water treatment and recycling systems, click here.

Minimize the use of detergents, caustic cleaners and other additives when pressure washing.

Minimize the amount of pressurized water used when boats are power washed. For example, wash the hull above the waterline by hand.

Regulatory Issues

A hazardous waste determination should be conducted on collected pressure wash wastewater to establish whether or not disposal of the collected material is subject to hazardous waste regulations [40 CFR 262.11, click here]. For more information on New York hazardous waste testing requirements, click here. While stored on-site, it must be managed in accordance with hazardous waste storage requirements [40 CFR 262.11, click here]. For more information on New York's Hazardous Waste Regulations and storage requirements, click here.

Pressure wash waste water should not be discharged to surface or ground waters without authorization from the state under the State Pollutant Discharge Elimination System (SPDES). For more information on the SPDES program in New York, click here.

If there is a stormwater discharge from your facility and power wash outdoors, you may have to register for a General Permit for the Discharge of Storm Water Associated with Industrial Activity ("Storm Water General Permit"). For more information on stormwater permitting in New York, click here.