Policy News - November 3, 2004

Controlling mercury to dodge TMDL calculations

State officials should have the freedom to reduce mercury emissions to help clean mercury-polluted lakes, rather than rely on the complex and costly federal Total Maximum Daily Load (TMDL) regulation, suggests a new proposal from Massachusetts, Maine, and Rhode Island. Massachusetts officials have taken the lead and have submitted to the U.S. EPA’s Region 1 office their comprehensive plan showing how power plants in their state will reduce emissions. If approved, the approach could be used to leverage stronger federal action on mercury.

According to the officials, the mercury-emissions reduction plans should substitute for the Clean Water Act (CWA) requirement that states calculate TMDL—the amount of pollution a water body can receive and still meet water quality standards—for contaminated lakes and streams. Most states have had difficulty calculating TMDLs, with only a few succeeding.

The draft plan builds on Massachusetts’ record of cutting mercury emissions in the state by 70% since the mid-1990s, says Arleen O’Donnell, deputy commissioner for policy and planning at the Massachusetts Department of Environmental Protection.

Massachusetts joined the governors of five other New England states and the premiers of Canada's four eastern provinces in 1998 to endorse a binational plan to cut mercury emissions by 50% by 2003 and 75% by 2010, with an ultimate goal of virtual elimination. The region has exceeded the first target, paring back releases by 55% from 1998 levels, O’Donnell says. A new law in Massachusetts will slash coal-fired power plants’ emissions of mercury by 85% by 2008 and 95% by 2012, according to the plan. The federal government hasn’t yet regulated mercury emissions from power plants.

“They make a good case that exchanging a solid implementation plan, which is not required by law, for a rough TMDL calculation is not a bad trade for the environment,” says Steve Silva, director of the water quality program for EPA’s Region 1. For EPA to approve the move, the state must convince the agency that it will meet water quality standards, he says.

But Massachusetts officials admit that their plan by itself won't meet federal water quality standards unless EPA requires other states to control their power-plant emissions. As much as 53% of the mercury deposited in New England and eastern Canada comes from outside the region, these officials say. If EPA approves the state’s plan, Massachusetts could end up violating the CWA, adds Christopher Kilian, senior attorney for the Conservation Law Foundation.

“By using Massachusetts as an example of a state that has taken steps to regulate its air sources, we think that it would be appropriate to call on the national government and other states to do the equivalent of what we have been able to accomplish here,” O'Donnell says. —JANET PELLEY