In 2017, an EPA rulemaking went into effect to help reduce mercury discharges from dental offices into publicly owned treatment works (POTWs). Entitled "Effluent Limitations Guidelines and Standards for the Dental Category" this rulemaking requires dental offices to use amalgam separators and employ best management practices recommended by the American Dental Association (ADA).
Because mercury is often found present in amalgam used for fillings, the use of amalgam separators was found to be a readily available technology used for capturing mercury before wastewater was to be discharged into sewer systems and local POTWs. This captured mercury can then be recycled.
While the final rule went into effect on July 14, 2017, affected sources (dental offices and dental laboratories) who were found subject to the rule were to comply with the standards by July 14, 2020.
One-Time Compliance Report
Any existing dental operations that were discharging into POTWs prior to July 14, 2017 are required to submit a one-time compliance report certifying compliance by October 12, 2020. Newly constructed or purchased dental offices must immediately install a separator and submit the one-time compliance report within 90 days of taking ownership.
Dental dischargers that do not place dental amalgam, and do not remove dental amalgam except in limited emergency or unanticipated circumstances, are exempt from further requirements as long as they certify as such in a one-time compliance report.
EPA has a Sample Compliance Report available on its Dental Effluent Guidelines website. Once completed, dental offices and dental labs located in Pennsylvania should send the compliance report to the proper local wastewater utility (or POTW) or to EPA Region 3.
Small businesses can find a list of contact for the National Pretreatment Program here.
Additional Resources and Information
EPA has published a Frequently Asked Questions document on the Dental Office Category Rule and the Pennsylvania Dental Association has available information on EPA's Amalgam Separator Rule.
In a study conducted by EPA in August 2008, it was reported that there were 7,225 dental laboratories and 122,918 dental offices operating in the US. It was further reported that 99.9% of those dental laboratories and 98.8% of those dental offices met the SBA definition of a small business.
According to the EPA's final rulemaking published in the Federal Register, unbound mercury is highly volatile and can easily evaporate into the atmosphere. An estimated 99.6% of dental mercury discharges are in solid form and thus will likely not volatize into the atmosphere. Therefore, EPA expects this will not pose any harm or increases in air pollution.