Thursday, March 19, 2009

Climate Change and a Novel Water Quality Case Could Have Major Impact on Decision-Making

Most of the time climate change issues don't enter into how Environmental Protection Agencies set nutrient limits in water bodies. That may change. Environmentalists are seeking to require the USEPA for the first time to consider climate change effects on water flow and activity when setting discharge limits for impaired waters.

The Conservation Law Foundation (CLF) is suing EPA over its approval of a phosphorus limit on Lake Champlain in Vermont. CLF wants EPA to consider climate change and its impacts on wet weather flows when setting the lake's total maximum daily load (TMDL). The TMDL is the maximum amount of a contaminant that a waterbody can accept without violating water quality limits. TMDLs take into consideration both point and non-point sources into impaired waters, and normally one would not even think about some global phenomenon like climate change. TMDLs tend to be local or regional.

Consideration of climate change impacts could sometimes result in stricter discharge limits, such as when increased precipitation could result in increased pollution runoff. But in other cases, e.g., if climate change causes more arid conditions, it could result in less runoff and fewer pollutants contributing to impairment.

Either way, the question comes down to whether EPA had sufficient information available and knowledge to consider climate change in the permit, which was issued by the Vermont Department of Environmental Conservation in 2002. CLF says EPA does have enough knowledge of the effects of climate change, and thus should have taken that into account in the permit. In early March a federal district court granted requests by both EPA and CLP to extend the deadline so they could enter into negotiations in hopes of finding an agreeable compromise.

If CLP wins the case, the next question would be how exactly the EPA would "consider" climate change?

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