New England Fish Chowder, Hold the Mercury, Please

The plan calls for a 98 percent reduction from 1998 levels of mercury from atmospheric sources in order to make mercury levels in fish low enough for the states to lift fish consumption advisories.

On October 24, the six New England states and New York state jointly submitted to the U.S. EPA a cleanup plan to reduce mercury entering into the states’ waters.

The plan, the Northeast Regional Mercury Total Maximum Daily Load, TMDL, was a collaborative effort between New England Interstate Water Pollution Control Commission and the states.

Atmospheric deposition of mercury originates from both natural sources and human activities. Natural sources of mercury include volcanoes, forest fires, and geologic deposits. Human sources include coal-fired power plants, municipal waste combustors, sewage sludge incinerators, and residential heating.

Based on recent research, this TMDL attributes 75 percent of mercury deposition in the region to human activities.

Although the vast majority of mercury in Northeast waterbodies is due to atmospheric deposition, about two percent comes from wastewater effluent. The sources of mercury in wastewater include dental amalgam and household use of products containing mercury.

The Brayton Point power plant in Massachusetts burns coal, oil, and natural gas. (Photo by Alexey Sergeev)

For several years the Northeast has experienced elevated levels of mercury in certain fish species that have resulted in thousands of fish consumption advisories at lakes and rivers across the region.

The approved plan addresses the requirements of the Clean Water Act that require states to develop pollution budgets, or Total Maximum Daily Loads for polluted waters.

To establish the mercury reduction targets each state analyzed fish tissue, evaluated information on atmospheric sources of mercury and estimated the level of reduction needed to meet the target levels in fish.

Approving the plan on December 27, the EPA said that, "Given the consistency of mercury levels in fish throughout the region, and the regional consistency of mercury inputs from the atmosphere, the collaborative approach among the states is a logical and effective way to address the problem."

The establishment of this mercury reduction plan builds on a number of on-going efforts by the Northeast states to lower mercury levels.

In their plan, the states said they are committed to reducing all in-state sources of mercury. "As a result," they said, "regional mercury emissions have decreased by approximately 70 percent between 1998 and 2002. This reduction was achieved primarily through stringent emission limits on municipal waste combustors and medical waste incinerators."

The Northeast states are continuing to make reductions through implementation of legislation to address sale and disposal of mercury-containing products, installation of dental amalgam separators, and emissions controls on coal-fired utilities.

Copyright Environment News Service (ENS) 2007. All rights reserved.