EPA has promulgated pretreatment standards to reduce discharges of mercury from dental offices into publicly owned treatment works (POTWs).
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.
Every time an amalgam filling is placed or removed, tiny particles can bypass chair side traps and make their way into the waterways. Dentists can virtually eliminate this problem by installing an amalgam separator, which captures 99% of mercury waste before it enters our wastewaters.
The effective date of the rule is July 14, 2017.
Dental offices that place or remove amalgam must operate and maintain an amalgam separator and must not discharge scrap amalgam or use certain kinds of line cleaners.
Existing Dental Offices
Existing dental offices must comply by July 14, 2020. Existing amalgam separators may be operated for their lifetime or ten years, whichever comes first.When a separator needs replacement, or the ten-year period has ended and the separator does not meet the standard of the final rule, a dental office must replace it with one that meets the requirements of the final rule.
New Dental Offices
The compliance date for new dental offices (“new sources”) is the effective date of the rule.
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.