Advocates applaud EPA's proposal to control dental mercury discharges

Today, Environmental Protection Agency Administrator Gina McCarthy proposed an effluent guideline rule to control dental mercury discharges and streamline oversight requirements for the dental sector. After more than four years of delay, advocates welcomed the agency's proposal.

"Mercury from dental clinics is by far the largest source of mercury in municipal wastewater, one of the largest product uses, and also the largest reservoir in use today," said Michael Bender, director of the Mercury Policy Project. "We applaud Administrator McCarthy's leadership in proposing regulations to reduce dental mercury discharges."

EPA's rule requires installation of amalgam separators — equipment to capture dental mercury before it goes down the drain — and implementation of best management practices. That way, mercury waste from dental fillings will be prevented from entering municipal wastewater or otherwise be improperly disposed of. In many states today, amalgam waste is flushed into chairside drains and enters wastewater systems, and then into the environment.

"Setting a pretreatment requirement for dental offices is a cost-effective method of keeping mercury out of our environment," said Laura Haight with NYPIRG. "New York has had a similar requirement in place for years. Amalgam separators are widely available, straightforward to install, operate without electricity or chemical addition, have low installation and maintenance costs, and facilitate easy recycling of mercury from dental fillings."

At least 12 states and a number of cities have already mandated amalgam separators at dental clinics, which can eliminate 95% to 99% of mercury discharges to wastewater. Yet in most states where amalgam separators aren't mandated, compliance is low and mercury discharges are high.

"Mercury released from amalgam fillings at dental clinics can be easily managed and prevented," said Elizabeth Saunders, Massachusetts director of clean water action. "As states like Massachusetts with existing programs have found, the amalgam separator rule can be designed to avoid any unnecessary regulatory burdens on states and publicly owned wastewater treatment plants, thereby minimizing costs."

Approximately 50% of mercury entering local waste treatment plants comes from dental amalgam waste, according to EPA. Once in the treatment plant, certain microorganisms can change elemental mercury into methylmercury, a highly toxic form that builds up in fish. Mercury contamination is the largest cause of fish consumption advisories in the US today.

EPA's proposed rule will be published in the Federal Register for public comment.

For more information visit http://water.epa.gov/scitech/wastetech/guide/dental/ and www.mercurypolicy.org

SOURCE: Mercury Policy Project