Identifying priority persistent pollutants in urban discharge

In 2007, the State of Oregon enacted legislation aimed at identifying persistent pollutants that could be discharged from municipal wastewater plants (WWTP), with the intent of reducing their occurrence through pollution prevention programs. This legislation defined a persistent pollutant as one that is toxic and persistent or bioaccumulative; a broad definition that required evaluation of diverse chemicals. This definition presented a significant challenge on how to address emerging persistent pollutants. With input from a science workgroup, an initial list of 2,130 chemicals was compiled from existing international, national and state efforts. Criteria for toxicity, persistence, and bioaccumulation were defined and used in two evaluation models (PBT Profiler and EPISuite) to score each chemical. Final prioritization was given to chemicals that could adversely impact state waters or chemicals that had significant public health concerns. A final list of 118 chemicals was adopted by the State. This list includes many current-use products that are found throughout urban landscapes, including: 1) 16 pesticides, 2) 17 consumer-related products, including pharmaceuticals and fragrances 3) 12 industrial compounds and flame retardants, 4) 14 combustion by-products and 5) five metals. The remaining chemicals were categorized as legacy pollutants, such as DDT and PCBs. The largest Oregon WWTPs will begin monitoring for these chemicals and ultimately develop management plans to reduce their discharge. The complex role of outreach and engagement to residents, businesses and local governments is discussed.