Bay Models Meet Approval
The public comment period for the Environmental Protection Agency's Chesapeake Bay restoration models is up, and although the models were met with mixed reviews, the EPA remains hopeful with prominent scientists' support.
"As the EPA has been working to develop the Chesapeake Bay [total maximum daily load], a lot of individuals and groups have been challenging the science behind the Chesapeake Bay restoration and the TMDL," said Travis Loop, the public affairs director for the EPA's Chesapeake Bay Program Office. "They've specifically questioned the computer models used. Now you have some of the absolute leading scientists, who weren't asked to do anything, saying that they're very credible tools."
Loop referred to three scientists — Donald F. Boesch, president of the University of Maryland Center for Environmental Science, John Wells, dean and director of the Virginia Institute of Marine Science, and Denice H. Wardrop, senior scientist at The Pennsylvania State University — who wrote a joint letter in praise of the models during the public comment session.
In the letter, they share their views on the proposed validity of the science behind determining and achieving the Chesapeake Bay watershed TMDLs — figures each watershed state will be asked to meet over the next two decades to reduce the amount of nitrogen, phosphorous and sediment pollution, as part of President Barack Obama's executive order to restore the bay.
In its main argument, the letter states that "scientists are acutely aware of the many unknowns and certainties about the properties, processes and parameters included in the models that limit the accuracy of any model, particularly models of such large and complex ecosystems as the Chesapeake Bay and its watershed. But, are these models useful in setting the direction, amount and distribution of nutrient and sediment load reductions required to achieve the designated water quality criteria? In our judgment, the consensus of the scientific community is that they are both useful and adequate for these purposes."
Furthermore, the team of scientists refuted the arguments of others who wish to "delay moving forward with implementation until [the models] are ‘perfect,' in fact, the models can, at this point, only be improved through this adaptive implementation approach."
In conclusion, they called the models "the best current incorporation of available science with which to set and allocate maximum loads within the watershed."
"These are well-respected scientists," Loop said.
Arguments against the TMDL models, he said, have come from nonscientific and nontechnical sources.
"They just questioned the accuracy of them, if they have all the right information being plugged into these computer models," he said.
By the time the public comment period ended on Nov. 8, Loop said, the EPA had received about 8,000 comments, 90 percent of which expressed support of the TMDLs.
The agency currently is reviewing the comments and considering them as it develops the final draft of the plan, which will contain an appendix of the EPA's responses to the comments, he said.
"The EPA's been working very hard with all of the states and making sure this thing goes where it needs to go," Loop said.
The agency now is helping the states to improve their initial TMDL plans; new drafts from each state will be due Nov. 29 and the EPA will officially establish a final TMDL by Dec. 31.
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