Boatyard Stormwater Treatment Technology Study

Project Overview.

This report summarizes the methods and results of data collected from a study of three stormwater treatment technologies that were installed at three boatyards around Puget Sound. These three technologies include (1) the StormwateRx Aquip™ (Aquip) installed at the Port of Edmonds Boat Workyard, (2) the Siemens Water Technologies Wastewater Ion Exchange (WWIX) Services installed at the Canal Boatyard, and (3) the Water Tectonics, Inc. Wave Ionics™ Electro-Coagulation System Treatment (Wave Ionics) installed at CSR Marine. Each technology was installed to treat runoff from approximately one to two acres of predominately impervious surfaces where boats are maintained and serviced. The Northwest Marine Trade Association (NMTA), Puget Soundkeeper Alliance (PSA), and Washington State Department of Ecology (WSDOE) collaborated on the study to assess the ability of the different technologies to remove contaminants, especially metals and TSS, from the boatyards’ stormwater runoff. A steering committee comprised of members and representatives from the NMTA, PSA and Ecology was put together to oversee the study.

Technology Description.

This section includes brief descriptions of the three technologies evaluated. More complete descriptions of each technology can be found at their respective websites which are listed below.

• (1) StormwateRx® Aquip™ (www.stormwaterx.com). The Aquip is a passive adsorptive filtration technology designed specifically for reduction of stormwater pollutants such as turbidity, zinc, copper and other metals from industrial sites, including boatyards. The treatment capacity of the Aquip system installed in the Edmonds Boat Workyard was 10 gallons per minute (gpm).
• (2) Siemens Water Technologies, Inc. Wastewater Ion Exchange Systems. The WWIX utilizes ion exchange resins and other media to remove specific ionic contaminants such as metals from stormwater and wastewater. The overall treatment capacity of the system installed at the Canal Boatyard was 10 gpm.
• (3) Water Tectonics, Inc. Wave Ionics™ electrocoagulation system treatment. The Wave Ionics is an electro-coagulation system that uses electrical current to coagulate particles by forcing contaminated water to flow between closely spaced metal plates across which an electrical potential is applied. The overall treatment capacity of the system installed at CSR Marine was 50 gpm.

Sampling Approach.

Rainfall and water quality data were collected for seven storm events for the Aquip and WWIX, and four storm events for the Wave Ionics between November 2007 and February 2008. Influent and effluent samples were collected at discrete flow rates of approximately 10 gpm for the Aquip, 13.5 gpm for the Wave Ionics, and 10 gpm for the WWIX using automated water quality samplers. Samplers were programmed to collect grab and time-paced composite samples, which were submitted for total suspended solids (TSS) and total and dissolved copper (Cu), lead (Pb) and zinc (Zn) analysis.