On June 14, 2017, EPA final ruling, 40 CFR 441 (Effluent Limitations Guidelines and Standards for the Dental Category), concerning standards and best practices for effluent dental water was published in the federal register. The ruling has established two best management practices (BMPs) to be adopted and requires a one-time certification of compliance for those subject under it.
The first BMP prohibits the discharge of amalgam waste into public water sewage and mandates the use of an amalgam separator. Since the dental industry alone is releasing about 5 tons of mercury-containing amalgam into the sewage systems, the EPA has enforced the rule for the betterment of the environment.
The second BMP forbids the use of oxidizing waterline cleaners in “dental unit water lines, chair side traps, or vacuum lines that lead to an amalgam separator.” The ruling goes into further detail stating oxidizing line cleaners, “including but not limited to, bleach, chlorine, iodine and peroxide, that have a pH lower than 6 or greater than 8,” must not be used to treat dental waterlines.
"The final rule is effective on July 14, 2017. The compliance date, meaning the date that existing sources subject to the rule must comply with the standards in this rule is July 14, 2020. After the effective date of the rule, new sources subject to this rule must comply immediately with the standards in this rule."
The EPA ruling published to the federal register can be found in full here:
WHY YOU SHOULD NOT USE OXIDIZING LINE CLEANERS
Sterisil Straw V2 - EPA Compliant waterline disinfectant for 365 days
The Role of the Amalgam Separator
Since Mercury is present in the dental waterline in both solid and dissolved form, the use of an amalgam separator accounts for 99.95% of the removal process. Most amalgam separators focus on removing solids but there is a recent push to develop separators with ion exchange capabilities to capture dissolved mercury.
Restrictions on Oxidizing Line Cleaners
One-time Compliance Report
Under the ruling, an existing practice will have 3 years and 90 days to comply with the two BMPs and submit their one-time compliance report. Newly constructed offices will have 90 days from the introduction of waste water into the public water supply.
This final ruling will take precedence over any existing local code or requirements for those subject under it.