In a recent post [“When is a Wetland a Wetland — and How Do We Find Out?“] we described the significant uncertainties in ascertaining the reach of the Clean Water Act over wetlands, ponds, drainage ditches and other small aquatic features only remotely connected to navigable waterways such as rivers and lakes.  On June 12, the debate over this contentious issue intensified as two key House Republicans submitted a letter to the Administrator of the U.S. Environmental Protection Agency asking a series of pointed questions about two upcoming EPA studies that could be used to justify an expansive interpretation of the Act’s coverage.

The letter—from Rep. Andy Harris (Chairman of the House Subcommittee on Energy and the Environment) and Rep. Bob Gibbs (Chairman of the House Subcommittee on Water Resources and the Environment)—requests detailed information on the studies, including a timeline of all past and expected future EPA actions, the purpose of the studies and the uses to which they will be put, a description of the EPA’s methodology and the process the agency will use to finalize the studies, and an explanation of how the studies will be independently prepared and externally peer-reviewed.

The first study will assess the economic benefits of protecting healthy watersheds.  In April 2012, the EPA published a fact sheet on this issue and its contractor (IEC) released a seeking expert analyses on how to quantify the contributions of clean water to the U.S. economy.  In its fact sheet, the EPA emphasizes that “healthy watersheds support healthy economies” and discusses how monetary values may be assigned to ecological benefits.

The second study will evaluate the connections between headwater streams and navigable waterways.  The EPA reportedly will use a wide range of scientific data to assess the role that the upper portions of a watershed play in contributing to the overall water quality downstream.

The letter asks the EPA to provide responses by June 26.  For those following the recent dramatic twists and turns of Clean Water Act jurisdiction, it should be an interesting summer.