EPA Agrees to Reconsider Lake Clean-up Plan

Photo from ixquick on flickr.com

In late April the EPA agreed to reconsider the Vermont portion of the Lake Champlain clean-up plan (known as a TMDL). The TMDL is used to set limits on the amount of pollution produced by wastewater treatment facilities and to set goals for pollution reduction efforts from other sources. The original TMDL had been approved in 2001, but pollution reduction efforts since that time have not had a measurable effect in the lake. Additionally, wetter weather since the time when the TMDL was developed has led to even more pollution loading from erosion. The decision came as a result of a law suit brought by the Conservation Law Foundation.

Reopening the TMDL poses challenges and opportunities, but is unlikely to affect overall efforts to manage the lake. The efforts of the state of Vermont have been guided by the best available science. The state has emphasized and prioritized appropriate actions and focal areas. State agencies have a strong conceptual model of phosphorus movement through the ecosystem and have developed programs to address each area where stopping such movements is appropriate. There are many possible reasons why in-lake responses have been so disappointingly slow.  

If EPA reopens the TMDL then LCC recommends that the Vermont Agency of Natural Resources consider separate TMDLs for separate lake segments. Such an effort would require an extensive planning effort, but it would allow managers to focus resources on the problems most acutely associated with each lake segment rather than pretending that all sources of lake pollution are universal. For example, much of the debate in the press has centered on the relative responsibility of wastewater treatment facilities. Yet not all facilities have the same impact on the lake simply by virtue of the segment to which they discharge. Separate lake-segment TMDLs would allow a focus on the facilities most likely to contribute to lake pollution.  

Pollution problems in Lake Champlain are not evenly distributed between the lake’s five principal segments. This fact is acknowledged in the detailed assessment of the lake clean-up plan but glossed over in press releases and political posturing. Phosphorus pollution problems substantially occur in the South Lake, Missisquoi Bay, and a portion of the Inland Sea, namely St. Albans Bay. Not only are pollution levels highest within these three segments, but they also serve as a source of pollution loading to adjacent lake segments. If phosphorus pollution is controlled in these three areas, the vast majority of the lake-wide problem will be resolved. That’s why LCC has long advocated to focus additional phosphorus reduction efforts and dollars on these sections of the lake.  

In considering separate TMDLs for separate lake segments, the work should begin with Missisquoi Bay. The bay receives a full 40% of Vermont’s share of Lake Champlain phosphorus pollution. It is directly connected to only one other lake segment and upstream of that. A single connection eases development of a TMDL. By contrast, identifying the relative pollution contribution from tributaries versus other lake segments will be much more difficult for lake segments like the Main Lake that have a direct connection to many other segments.  

There is precedent for segregating water bodies into distinct segments each of which receives their own pollution remediation plan. In Vermont, only portions of many rivers have been identified as in need of a TMDL rather than the entire river. In New York, a separate phosphorus TMDL exists for Little Sodus Bay on Lake Ontario, rather than for the entire lake.  

Development of separate TMDLs for different lake segments will present technical challenges and be time-consuming, however, the outcome will be a better focus on the specific causes of lake pollution and how they differ across the state.