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Tale of a TMDL
NEIWPCC and States File High-Profile Plan to Reduce
Mercury in Our Waters
by Susy King, NEIWPCC
On October 24, after nearly two years of planning and preparation, NEIWPCC and the Northeast states officially submitted the Northeast Regional Mercury TMDL to the U.S. Environmental Protection Agency. The TMDL, which stands for Total Maximum Daily Load, identifies specific steps to be taken to reduce mercury in the region’s waters. By statute, EPA has 30 days after the submittal of a TMDL to either approve or disapprove it. If EPA rejects the plan, the agency has another 30 days to develop an alternative TMDL. As this issue of IWR went to press, EPA had yet to announce its decision on the mercury plan, but the delay was to be expected. In the past, EPA has taken longer than 30 days to consider a TMDL, particularly when the issues are complex—which is certainly the case with this submission.
The TMDL is a new step in the fight against an old problem—mercury pollution in Northeast waterways. For years, mercury contamination has led states to issue guidelines on just how much of various types of fish can be safely eaten. Throughout those years the challenge has been how to solve the mercury problem so consumption advisories are no longer necessary.
The Northeast states haven’t shied away from the challenge. Rather, they’ve put tremendous effort into successfully reducing mercury within their borders. But other parts of the country have been slow to follow—and that’s a problem when you consider how much of the mercury in the Northeast originates from sources outside the region.
With the TMDL, the states are trying a powerful new tactic to reel in mercury emissions from sources near and far. The way the TMDL came together is a classic case study in what can be achieved when the states and NEIWPCC work together in pursuit of a common goal.
An Insidious Foe
The Northeast states had long been aware of the problems caused by mercury, due to plentiful research showing it to be a potent neurotoxin that poses a particular risk to developing fetuses. Concern increased as awareness grew of how easily mercury enters the environment and our bodies. Mercury primarily originates from air pollution sources such as coal-fired power plants, municipal waste combustors, and sewage sludge incinerators. Once in the air, it over time falls directly into surface waters or onto land, where it can be carried by runoff into waterways—a phenomenon known as atmospheric deposition. Once in the water, bacteria convert the metal to methylmercury, a form that bioaccumulates in fish and other aquatic organisms. When we eat the fish, we’re exposed to the mercury inside.
With this information in mind, and a sense of the growing threat from mercury, the Conference of the New England Governors and Eastern Canadian Premiers (NEG-ECP) Committee on the Environment released a regional Mercury Action Plan in 1998. The plan identified steps to address those aspects of the mercury problem in the region that are within the region’s control or influence. The long-term goal was to virtually eliminate regional anthropogenic mercury emissions—that is, those emissions caused by human activity. To ensure progress, short-term goals were adopted. The Mercury Action Plan originally set a target of a 50 percent reduction in regional mercury emissions by 2003. In 2001, another interim goal was added: a 75 percent reduction by 2010.
Fast forward to 2005: Implementation of the Mercury Action Plan had resulted in reductions of regional mercury emissions of greater than 50 percent, but fish tissue mercury concentrations were still high enough to require fish consumption advisories. It wasn’t hard to figure out why. Scientists know that airborne mercury can travel far from its source, and that air currents often carry to the Northeast whatever’s in the air to the west. Combine that with the fact that mercury reductions outside the Northeast had not been nearly as great as those within the region, and the conclusion was obvious: the in-region progress on mercury was being offset in part by a lack thereof elsewhere. If levels of mercury in fish were ever to decline to safe levels, we needed more aggressive out-of-region reductions.
Devising a Strategy
In December 2005, NEIWPCC and our member states—Connecticut, Maine, Massachusetts, New Hampshire, New York, Rhode Island, and Vermont—began collaborating to develop a plan that would quantify the necessary reductions from mercury sources both within and outside of the region. While we were all motivated by the desire to reduce mercury in our waters, there was the added incentive of federal law. The Clean Water Act requires that states develop lists of impaired waters—waters that are not meeting their water quality standards—and develop Total Maximum Daily Loads, or TMDLs, for them. A TMDL is a calculation of the maximum amount of a pollutant that a water body can receive and still meet its water quality standards. The allowable amount of the pollutant is allocated to point and nonpoint sources.
In the Northeast, over 10,000 lakes, ponds, and reservoirs, and over 46,000 river miles are impaired for fish consumption due to mercury pollution, so there was no question that a TMDL was required. But how to do it? In general, states develop TMDLs for individual water bodies or a small group of water bodies. In the case of Lake Champlain and Long Island Sound, two states worked together on TMDLs for large interstate water bodies. But the development of a Northeast Regional Mercury TMDL, which involved seven states and thousands of water bodies, was truly a unique case. It would be a true test of the effectiveness of regional collaboration.
Thankfully, we had a precedent: the Minnesota Statewide Mercury TMDL. Although it was a state plan, not regional, the main goal was the same—to make reductions in the atmospheric deposition of mercury. It also had survived the scrutiny at EPA, which approved it in March. Hence, throughout the development process, we used the Minnesota TMDL as a model. For example, the TMDL process requires calculation of an allowable wasteload allocation (load from wastewater sources) and load allocation (load from nonpoint sources). As in Minnesota, we determined that the vast majority of allowable mercury load was in the load allocation. And since the majority of that allocation originates from atmospheric deposition, that was where the bulk of the reductions needed to be made.
Down to Business
As a means of gauging how far we’d come on mercury, and how far we needed to go, we used a baseline year of 1998 to correspond with the beginning of the NEG-ECP Mercury Action Plan. Data were compiled from a number of sources to calculate the baseline mercury deposition load, wastewater load, and fish tissue concentrations. We then compared the existing fish tissue concentration to a target fish concentration to calculate the necessary reduction in mercury loading and to establish the ultimate mercury goal. The determination: a minimum reduction of 87 percent in in-region and out-of-region anthropogenic sources of mercury atmospheric deposition is needed to meet desired fish tissue levels.
While the Northeast states have already accomplished atmospheric deposition reductions of more than 70 percent, a reduction of 87 percent or higher is still a lofty goal. When taking into consideration that the reductions must also be accomplished for sources outside of the region, the task becomes even more challenging. To address this issue, we broke down implementation of the TMDL into three phases. The first two phases correspond with the timing and goals of the regional Mercury Action Plan. In Phase I, which began in 1998 and ended in 2003, we required reductions of 50 percent. Phase II runs from 2003 to 2010, and has a reduction goal of 75 percent. Phase III begins in 2010, but its final reduction goal and end date won’t be determined until Phase II is done, when evaluation of emissions, deposition, and fish tissue data could point to a need to revise the original reduction goals.
How will these reductions be achieved? Within the region, states will continue on the mercury reduction paths they have already been following to virtually eliminate all in-region sources of mercury emissions and discharges. This includes implementation of legislation and regulations pertaining to emissions from coal-fired power plants, sale and disposal of mercury-containing products, and installation of dental amalgam separators.
As for the rest of the country, the Northeast states are asking EPA to enact a rule that would require 90 percent mercury control from all coal-fired power plants as a first step. This would be an alternative to EPA’s Clean Air Mercury Rule currently in place that will result in a 70 percent reduction when fully implemented. (Many states, including all the Northeast states, are also involved in litigation against EPA on this issue. To learn more, see “Legal Lines” on page 8.)
Rewarding Process
As the TMDL procedure requires that states release a draft for public comment prior to submitting a final TMDL to EPA, NEIWPCC and the Northeast states released a draft version of the Northeast Regional Mercury TMDL on April 11. The TMDL garnered media attention, with articles on its release appearing in the New York Times, Boston Globe, and other regional and national publications. To spread word about the TMDL to the public, NEIWPCC and state staff conducted eight public informational meetings in five of the participating states. The public comment period lasted 59 days, with NEIWPCC and the states receiving comments from 14 different groups.
After several months of revising the draft based on the feedback, we arrived at the final version of the plan, the one submitted to EPA on October 24. If approved and implemented, we can reasonably expect that one day everyone will once again be able to safely eat fish caught in the waters of the Northeast. That may seem hard to believe, given how accustomed we’ve grown to fish consumption advisories. But it’s believable and achievable—with the TMDL as our tool.
The complete text of the Northeast Regional Mercury TMDL is available at www.neiwpcc.org/mercury, where you can also access news related to this effort, such as any announcement from EPA, that may have occurred since the printing of this issue.
Editor’s Note: Susy King (sking@neiwpcc.org), the writer of this article, is a NEIWPCC Environmental Analyst. She played a prominent role in the development of the Northeast Regional Mercury TMDL, as did Beth Card (bcard@neiwpcc.org), NEIWPCC’s Director of Water Quality Programs. Both served on the project’s technical workgroup, which also included Traci Iott and Paul Stacey of Connecticut DEP; Andy Fisk and Barry Mower of Maine DEP; Rick Dunn, Russ Isaac, and C. Mark Smith of Massachusetts DEP; Gregg Comstock, Bob Estabrook, and Peg Foss of New Hampshire DES; Jay Bloomfield, Dick Draper, Ron Entringer, and Scott Quinn of New York State DEC; Scott Ribas and Elizabeth Scott of Rhode Island DEM; and Tim Clear and Neil Kamman of Vermont DEC. Their contributions and the strong support of NEIWPCC’s Executive Committee were critical factors in the successful completion of this project.
One final note: Among the many reporters that covered this story was Vermont Public Radio’s John Dillon. NEIWPCC’s Beth Card was among the subjects he interviewed, and Dillon included one of Card’s comments in his piece that aired on October 30. It can be heard online at www.vpr.net/news_detail/77965/.