US EPA to study mercury impact in Florida everglades and Wisconsin

Many states have identified mercury as a major cause of water quality problems. This is the first time EPA and the states have tackled the problem of air-borne mercury pollution and its effect on water quality.

The project will be conducted in a 700 square-mile (181,300 ha) portion of the Everglades 30 miles west of Miami known as Water Conservation Area 3A, and in Devil’s Lake, a small waterbody near Madison, Wis., with a watershed of about two and a half square miles.

Both these areas are on their state’s list of ‘impaired’ waterbodies, and in public advisories to limit fish consumption due to high levels of mercury in fish. The goals of the project include determining the relative contributions of mercury air emissions and wastewater from various sources; identifying how much mercury is deposited by local and distant sources; and assessing how federal and state air and water programs can work together to reduce mercury contamination of water.

The EPA plans to release the project results in about a year. This project will help States develop Total Maximum Daily Loads (TMDLs) for waterbodies contaminated by mercury. TMDLs are a key requirement of the Clean Water Act, whereby a State identifies specific waterbodies that do not meet water quality standards and establishes specific pollution reduction targets for meeting those standards.

States have estimated that approximately 2,000 waterbodies are polluted by mercury and other metals, many from air sources; TMDLs will be required for each of these waterbodies.

The links below are EPA’s air quality programs