Reducing the Runoff – A Case Study of Stormwater Management at a Small Coastal Industrial Facility

Charleston Boatyard, a ship building and repair facility located along the Oregon coast, undertook a campaign in 2001 to return its operations to environmental compliance and prevent future recontamination of a coastal estuary. Its recipe for success included hotspot remediation and construction of stormwater best management practices such as source controls and passive stormwater filtration. The facility is now compliant with its general industrial stormwater permit, has returned to economic viability and is an environmental steward in the community.This paper presents an environmental case history of Charleston Boatyard, reviews improvements to the site and stormwater discharge quality as a result of facility modifications, and discusses testing done to optimize pollutant removal efficiency of The Stormwater Management StormFilter® (StormFilter), a passive, adsorptive media filtration system for boatyard and shipyard applications. Site modifications including use of the media filtration systems reduced suspended solids concentration by greater than 90% and heavy metals concentrations by 70% to 87%, achieving the permit requirement of continuous environmental improvement and progress toward benchmark goals.Bench testing of various media configurations found that the StormFilter with CSF® leaf media and perlite/zeolite media performed equally well, reducing the concentration of suspended solids in stormwater by up to 58% and reducing the metals concentration in stormwater by up to 67%. Reducing the flow rate and media gradation in the StormFilter cartridges was found to improve suspended solids removal by 7% and 27%, respectively, and metals removal by up to 12% to 20%, respectively. This testing demonstrates the value to boatyards and small shipyards of passive adsorptive media filtration with fine gradation organic media for removal of typical industrial stormwater pollutants from these sites.