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Dental Effluent Guidelines
- Federal Register Notice (PDF) (October 22, 2014)(30 pp, 457 K, About PDF)
- Support documents, including:
- Fact sheet
- Technical and Economic Development Document
Describes industry processes, pollutants generated, available control & treatment technologies, the technical basis and costs of the proposed rule
Documents related to this rulemaking can be found on EPA’s docket at regulations.gov. The Docket Number is EPA-HQ-OW-2014-0693.
The public comment period closed on February 20, 2015.
Across the United States, many states and municipal wastewater treatment plants (publicly owned treatment works) are working toward the goal of reducing discharges of mercury to POTWs.
Mercury is a persistent bioaccumulative toxic element. It is a concern to human health when fish and shellfish convert it to methyl mercury, which can harm the nervous systems of fetuses, infants and children exposed through fish and shellfish consumption. Many studies have been conducted in an attempt to identify the sources of mercury entering these POTWs.
Dental clinics are the main source of mercury discharges to POTWs
A 2003 study estimated that 50 percent of mercury entering POTWs was contributed by dental offices
Dentists discharge approximately 4.4 tons of mercury each year to POTWs
About 160,000 dentists working in over 120,000 dental offices use or remove amalgam in the United States; almost all of these send their wastewater to POTWs
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. Some of the waste amalgam particles that reach the sewer system settle out in the sewers, and some are carried to POTWs. The physical treatment processes used in POTWs remove about 90 percent of the mercury received in wastewater. The mercury removed from wastewater then resides in the biosolids or sewage sludge generated during primary and secondary treatment processes.
Memorandum of Understanding on Reducing Dental Amalgam Discharges
Memorandum of Understanding: ADA, NACWA & EPA (December 29, 2008)
Health Services Industry Detailed Study: Dental Amalgam (August 2008)
For additional information regarding dental amalgam, please email Damon Highsmith (firstname.lastname@example.org) or call him at 202-566-2504.