2010-10-26_PWETC_Minutes - Laserfiche WebLink

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8. Polycyclic Aromatic Hydrocarbon (PAH) Background Information Chair DeBenedet noted the additional information provided by staff on addressing issues of Polycyclic Aromatic Hydrocarbon's (PAH's) in currently being found in pond sediment in the community and area. Mr. Schwartz provided detailed information on recent findings in his staff report dated October 26, 2010; and provided a model ordinance developed by the League of Minnesota Cities (LMC) for consideration by the PWET Commission and subsequent recommendation to the City Council. Mr. Schwartz reviewed the two (2) ponds having been recently tested through watershed projects. Mr. Schwartz advised that testing, as well as disposing of sediment containing PAH's was extremely expensive for communities. Discussion included common sense incentives to remove PAH sediment from the system; language of the model ordinance and involvement of the City Attorney on a more formal format before presentation in draft form to the City Council; how and where sediment was disposed of in specific landfills equipped to seal it; current work among MPCA staff and City Engineers to determine if a lower cost method, such as diluting it and mixing it with soils or composting, was feasible. Member Stenlund noted that such composting was possible, as long as it had a restricted use, such as on golf courses or tier one level soils, and not used for children's playgrounds or growing vegetables. Further discussion included typical seal coating materials used by Cities not including this material, but uses still found by private vendors for spraying commercial parking lots. Chair DeBenedet noted that restricting use would not provide any new restrictions to homeowners or additional City cost, but actually save money for residents in the future by making storm water ponds safer, cleaner and more environmentally benign; and ponds not having to be dredged as often to remove pollutants. Chair DeBenedet noted that the pollutants impacted natural streams and lakes, with adverse affects on biological species in those bodies of water. Member Stenlund noted that there would still be materials draining off parking lots even with restricting coal tar products, but that a longer time frame would be achieved before a pond reached a tier 3 contamination level. Additional discussion included percentages of dilution for coal tar based sealers and /or mixing the material with asphalt products and related environmental impacts based on model ordinance language; references and further clarification to state statue in model ordinance language; how to change behavior and enforce the ordinance once enacted; and non permitted or licensed use by vendors of PAH materials. Page 12 of 14