On Thursday, Dec. 15, 2016, Environmental Protection Agency (EPA) Administrator Gina McCarthy signed a rule requiring dental offices to use separators to remove mercury from amalgam prior to discharging into publicly owned wastewater treatment plants known as publicly owned treatment works (POTWs).
This rule also requires dental offices to adopt two best management practices recommended by the American Dental Association to further prevent mercury from entering the waste stream: One prohibits the discharge of scrap and the other prohibits the use of line cleaners that may lead to the dissolution of solid mercury when cleaning chair-side traps and vacuum lines. (Bloomberg BNA)
The EPA estimates about 103,000 dental offices use or remove amalgam in the U.S.; almost all of these send their wastewater to publicly owned wastewater treatment plants. The agency estimates dentists discharge approximately 5.1 tons of mercury as well as 5.3 tons of other metals this way each year. (Bloomberg BNA)
The pretreatment rule was proposed in October 2014 in compliance with Section 304 (a) of the Clean Water Act (79 Fed. Reg. 63,258). WEF and other organizations provided comments urging EPA to consider less burdensome requirements which have been integrated into the final rule.