EPA sticks by Hinkson stormwater rules

The Environmental Protection Agency today issued final regulations that mandate steep reductions in stormwater flowing into Hinkson Creek.
Columbia, Boone County and MU vigorously opposed the proposed regulations known as the Total Maximum Daily Load, or TMDL, and argued that it could cost several hundred million dollars to implement.
The EPA retained the 40 percent reduction in stormwater flow into the creek included in its draft TMDL and said the local governments were overestimating the cost. But the agency clarified in the final version that the TMDL will be implemented in stages and could be revised during the process.
The EPA said no one pollutant exceeds regulatory limits, but a toxic mix of pollutants is swept into the creek after rainfall flows off of impervious surfaces such as parking lots.
Regulators at the EPA are implementing the rule in response to a 2001 lawsuit brought against it by the American Canoe Association and the Sierra Club. The ruling in that case stipulated a Dec. 31, 2010 deadline, but the EPA asked for a one-month extension in December.
Missouri has listed the Hinkson Creek as impaired since 1996 because of urban runoff. The watershed encompasses most of the city limits, and the development boom of the last two decades has substantially increased the amount of impervious surface in the watershed.
Representatives of the city, county and university argued that the studies conducted by the Missouri Department of Natural Resources are outdated. The most recent data collected by DNR was in 2006.
Local officials have also argued that using stormwater as a conduit for unknown pollutants is an untargeted, expensive approach with no guarantee for success. Other EPA regions in the country have issued TMDLs that target stormwater runoff, but until now, Region 7, which covers Missouri, has not. The EPA is issuing regulations for streams in the Springfield area that also target stormwater, though the agency’s administrators said that area has not protested as vigorously as Columbia.
In its final draft, the EPA clarifies that the TMDL will be implemented in phases and can be revised throughout the process. The agency recommends that the local entities begin collecting new data on biological life in the stream as well as water quality measures that may be used to revise the TMDL. At the same time, though, EPA recommends local governments and the university eliminate “harmful bottom deposits” in the stream, “vigorously” enforce storm water ordinances and improve best management practices controlling erosion (silt fences and rock berms, for example) in the watershed.
The TMDL also says that the “EPA anticipates” long term efforts such as incorporating more green infrastructure in development, continuing watershed restoration projects and forming more watershed protection groups.
The city, county and university’s attorney in the matter, David Shorr, has said the entities may decide to challenge the TMDL. Shorr could not be reached early Monday afternoon.