Hull Wash Water Management Options at Boatyards and Marinas

Wash water generated by pressure washing of boat hulls may contain anti-fouling paint residues that are harmful to aquatic organisms. Wash water with deleterious anti-fouling residues must not be allowed to enter the aquatic environment.  The deposit of deleterious substances to fish-bearing waters is a contravention to subsection 36(3) of the Fisheries Act.

 

The purpose of the flowchart below is to guide boatyard and marina operators through the wash water management process. More detailed information on wash water management strategies can be found in the October 2006 Environment Canada Hull Maintenance Best Management Practices workshop materials.

Flowchart illustrating hull wash water management options.

         

.The first step is to contain and collect the wash water. The wash water can then be treated on-site or off-site. In both cases, there may be provincial regulations applicable to your facility. In British Columbia, contact the nearest regional office of the provincial Ministry of Environment to determine if your wash water meets the definition of hazardous waste under the provincial Hazardous Waste Regulation and if there are other applicable regulations or requirements.  The off-site transportation of hazardous waste should be made by a provincially licensed waste transporter and the waste should go to a licensed hazardous waste management facility for appropriate disposal.  Information on other provincial authorities is available here.

 

Primary treatment systems are specifically designed to remove most of the hydrocarbons and heavy metals from the wash water.  After primary treatment, the treated effluent could be discharged into the sanitary sewer if this is permitted under municipal/regional bylaws.  Alternatively, the treated effluent could go through an on-site secondary treatment system to further polish it to a condition that could be recycled for pressure washing again. Anyone considering the discharge of untreated or treated wash water into the sanitary sewer is advised to first obtain permission from the local municipality or regional district to do so. Remote sites may want to consider evaporation of the treated wash water, but local and/or provincial authorities must be consulted regarding any air emission requirements.