The Penobscot is polluted with mercury. Without the EPA, it would be much worse.

Editor's note: The following opinion piece by Fellow Aram Calhoun and Dianne Kopec first appeared in the Bangor Daily News.

As the name implies, the goal of the U.S. Environmental Protection Agency is to protect our environment, and it has worked toward that goal since it was created in 1970. That start date is important to the people and the environment of the lower Penobscot River, for in late 1967, the HoltraChem chlor-alkali plant began operating in Orrington on the banks of the river. In the first four years of the plant’s operation, waste mercury was routinely discharged into the river. Much of that mercury continues to contaminate the Penobscot.

We ask that the community, and Sens. Susan Collins and Angus King — who will soon vote on the nominee to head the agency, Scott Pruitt — consider the value of the EPA and the critical importance of appointing a director who embraces the mission of protecting our environment.

We are scientists. We examined the impact of the mercury discharges into the river as part of the Penobscot River Mercury Study, an independent court-ordered study of mercury contamination of the Penobscot River from the HoltraChem plant. This work gave us first-hand knowledge of the value of the EPA and of the environmental consequences when regulations are absent or not enforced.

One of the first actions of the EPA was a thorough revision of water pollution laws and the creation of the Clean Water Act, which was passed by Congress in 1972. For the first time in our history, the government began regulating pollutant discharges into surface waters. It was no longer legal for the Orrington chemical plant to dump its waste mercury into the Penobscot. Instead, HoltraChem began storing the waste mercury in landfills that greatly reduced the amount of mercury entering the river. Yet, roughly 90 percent of an estimated nine tons of mercury that was ultimately released into the Penobscot River was discharged before the EPA began regulating pollutant discharges into our rivers, streams and lakes.

Today, the evidence of those mercury discharges can be seen in the sediment of the Penobscot River. Buried 16 inches below the surface of the sediment is a layer of extreme mercury contamination, deposited during the early years of plant operation. The sediment deposited after EPA was created is less contaminated. Yet, buried contaminants do not always remain hidden. River and slough channels can change course, releasing long-buried mercury into the surface sediment that is swept up and down the river with the tide. So in some parts of the lower Penobscot the most contaminated sediment is not buried, but near the surface, where it enters our food web and accumulates in our fish, birds and lobster.

Now 50 years later, we have mercury concentrations in waterfowl almost four times greater than the Maine action level for mercury in muscle tissue, prompting the state’s first health advisory on the consumption of breast meat from ducks. Migratory song birds arrive in marshes along the lower Penobscot with low mercury burdens, but quickly accumulate mercury concentrations in their blood that exceed levels known to cause reproductive failure. Average mercury concentrations in lobster living near the mouth of the Penobscot River are two to three times greater than the Maine action level, and individual lobster have concentrations over six times greater. There is now a state ban on lobster harvesting in that area.

Without EPA regulations, the river would be even more contaminated.

Finally, mercury concentrations in the surface sediments of the river are seven to 10 times greater than background concentrations in rivers Down East, and we estimate it will take a minimum of 60 to 400 years, depending on the area, for the Penobscot to clean itself.

Pruitt, the Oklahoma attorney general, has been nominated to head the EPA, despite the fact that he is a leading advocate against the agency. His history of suing the EPA over environmental regulations, the same regulations that now limit discharges to the Penobscot, should disqualify him from service as the agency’s director.

This is only one example of the positive role the EPA plays in safeguarding public and environmental health. Environmental regulations save our country money, provide jobs, and ensure the health of all animals, plants and the humans who see clean air, water and soil as an American right. The EPA needs a leader who will defend that right.

Dianne Kopec is an adjunct instructor in the department of wildlife, fisheries, and conservation biology at the University of Maine in Orono. Aram Calhoun is a professor of wetlands ecology at UMaine. Peter Santschi, a regents professor in the department of marine sciences at Texas A&M University in Galveston, and Ralph Turner, a mercury researcher at RT Geosciences Inc., also contributed to this piece.