Effluent Guidelines

Dental Effluent Guidelines

""EPA is promulgating pretreatment standards to reduce discharges of mercury from dental offices into publicly owned treatment worksHelppublicly owned treatment worksA treatment works that is owned by the state or municipality. (POTWs).

Dental offices discharge mercury present in amalgam used for fillings. Amalgam separators are a practical, affordable and readily available technology for capturing mercury and other metals before they are discharged into sewers that drain to POTWs. Once captured by a separator, mercury can be recycled.

Existing dental offices must comply within three years after the effective date of the rule. EPA expects compliance with this final rule will annually reduce the discharge of mercury by 5.1 tons as well as 5.3 tons of other metals found in waste dental amalgam to POTWs.

On this page:


Mercury is a potent neurotoxin that bioaccumulates in fish and shellfish. Mercury pollution is widespread and a global concern that originates from many diverse sources such as air deposition from municipal and industrial incinerators and combustion of fossil fuels.

Key facts about dental clinics and mercury:
  • Dental clinics are the main source of mercury discharges to POTWs.
  • EPA estimates about 103,000 dental offices use or remove amalgam in the United States; almost all of these send their wastewater to POTWs.
  • Dentists discharge approximately 5.1 tons of mercury each year to POTWs; most of this mercury is subsequently released to the environment.

Mercury-containing amalgam wastes may find their way into the environment when new fillings are placed or old mercury-containing fillings are drilled out and waste amalgam materials that are flushed into chair-side drains enter the wastewater stream. Mercury entering POTWs frequently partitions into the sludge, the solid material that remains after wastewater is treated. Mercury from waste amalgam therefore can make its way into the environment from the POTW through the incineration, landfilling, or land application of sludge or through surface water discharge.

Top of Page


The Federal Register notice for the final rule is not yet published. A pre-publication version is available below. EPA will update this web page when the rule is published. The effective date of the rule will be 30 days after publication.

Existing Dental Offices

Existing dental offices must comply within three years after the effective date of the rule.

New Dental Offices

The compliance date for new dental offices ("new sources") is the effective date of the rule.

Reporting Requirements

Existing and new sources must submit a one-time compliance report. See the Federal Register notice for details. EPA has not prepared an example compliance report at this time.

Top of Page


Final Rule

  • Final rule (signed December 15, 2016)
    The final rule has been signed by the EPA Administrator and is being prepared for publication.
  • Fact sheet

Additional documents related to this rulemaking can be found on EPA’s docket at regulations.gov. The Docket Number is EPA-HQ-OW-2014-0693.

Proposed Rule

Additional Information

For additional information regarding the Dental Effluent Guidelines final rule, please email dentalamalgamfinalrule@epa.gov .

Top of Page