The effect of amalgam separators on mercury loading to wastewater treatment plants.

Mercury (Hg) release from dental offices has become an acute issue for the dental profession and has resulted in efforts by regulators to mandate both the use of Best Management Practices (BMPs) as well as the installation of amalgam separators. Concern has been expressed by some regarding the efficacy of amalgam separators in reducing the Hg loads to wastewater treatment plants (WWTPs). Data from several Publicly Owned Treatment Works (POTWs) serving areas with installed bases of separators suggest these devices can substantially reduce Hg burdens to WWTPs. The data consists of Hg levels in sewer sludge (biosolids) and in some cases includes Hg concentrations in WWTP influent and effluent. Data comes from various geographical locations, and suggest separators can have a positive effect in reducing the amount of Hg reaching WWTPs.