Dental Amalgam

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​Dental amalgam is a mixture of metals, consisting of liquid (elemental) mercury and a powdered alloy composed of silver, tin, and copper. Mercury is a potent neurotoxin that bioaccumulates in fish and shellfish. Mercury-containing amalgam wastes may find their way into the environment if improperly managed by dental offices. Consequently, the Environmental Protection Agency promulgated the Dental Amalgam Rule to regulate the discharge of mercury from dental facilities.

The Dental Amalgam Rule

On June 9, 2017, the Environmental Protection Agency enacted the Dental Amalgam Rule to reduce the amount of mercury introduced to the environment by dental amalgam. Existing dental facilities subject to the rule were required to comply with the standards by July 14, 2020.

For dental dischargers whose first discharge into the City of Phoenix POTW occurred after July 14, 2017, “new sources", compliance with standards is required immediately and a One-Time Compliance Report certifying such must be submitted to the Control Authority no later than 90 days following the introduction of wastewater to the sewer.​

The rule requires dental facilities to install and operate an amalgam separators(s), to implement two Best Management Practices (BMPs), and to submit a One-time Compliance Report to the Control Authority. City of Phoenix Environmental Services Division is the Control Authority for all dental facilities that discharge to the City of Phoenix sanitary sewer. Thereafter, the dental office will be required to conduct ongoing operation and maintenance and keep associated records. These activities can be facilitated by third parties such as dental office suppliers and amalgam separator manufacturers.​