A Comparison of Two Media Filtration BMP Treatments for the Removal of PAHS and Phthalates from Roadway Runoff
Urban runoff is a major contributor to the degradation of our urban streams, rivers, and lakes (Pitt, 1995). Organic pollutants, such as PAHs and phthalates, in urban stormwater can contribute to receiving water degradation (EPA, 1983). A study in Rhode Island’s Narragansett Bay watershed found that urban runoff accounted for 71 percent of the total inputs to the bay for higher molecular weight PAHs, and for 36 percent of the total PAHs (Hoffman et al, 1984). Testing done in 2003 by King County, the City of Seattle, and the City of Tacoma found high levels of phthalates in products such as brake pads and tires used in vehicles (King County et al, 2004 and City of Tacoma, 2005). In the Lower Duwamish Waterway in King County, Washington and in the Thea Foss Waterway in Tacoma, Washington these products are thought to contribute phthalates to surface waters by atmospheric deposition or direct deposition and stormwater runoff (King County et al, 2004). This contribution of PAHs and phthalates to our waters is a regional concern in Western Washington State if not a national and international concern.