- Industrial Pretreatment
- Dental Dischargers
COVID-19 UPDATE: EPA has not extended the deadline dates below for compliance with the Dental Office Category Rule. As such, all non-exempt dental facilities are expected to make every effort to comply with their environmental compliance obligations. If compliance is not reasonably practicable due to the COVID-19 situation, notify us immediately and we will provide guidance on how to proceed.
On July 14, 2017, U.S. EPA established Dental Office Category regulations to reduce discharges of mercury from dental offices into the sanitary sewer system. Mercury and other metals used to make dental fillings (known as "amalgam") that enter the sewer system ultimately end up back in the environment either through discharge of reclaimed wastewater back to the surface waters or by way of land application of biosolids. The Des Moines Metropolitan WRA serves as the local Control Authority for dental offices within the Des Moines Metropolitan Area and is the governmental entity to which the one-time compliance reports shall be sent.
Exempt from this rule (including submission of the one-time compliance report) include those facilities that:
- Exclusively practice oral pathology, oral and maxillofacial radiology, oral and maxillofacial surgery, orthodontics, periodontics, and/or prosthodontics
- Discharge to private septic systems
- Are mobile units
- Transfer waste to a Centralized Waste Treatment Facility
For dental offices in operation prior to July 14, 2017 (i.e. “existing sources”):
- Dental offices that do not place or remove amalgam need only submit the One-Time Compliance Report by October 12, 2020.
- Dental offices that place or remove amalgam must install an ISO 11143 compliant amalgam separator by July 14, 2020 and must submit the one-time compliance report by October 12, 2020.
- Dental offices that had an amalgam separator installed prior to July 14, 2017 may continue to operate and properly maintain that device until June 14, 2027 or when the unit needs to be replaced, whichever comes first. The one-time compliance report must be submitted by October 12, 2020.
For dental offices in operation on or after July 14, 2017 (i.e. “new sources”):
- Dental offices that do not place or remove amalgam must submit the One-Time Compliance Report within 90 days of the start of business operations.
- Dental offices that place or remove amalgam must immediately comply by having an ISO 11143 compliant amalgam separator properly installed at the start of business operations and must submit the one-time compliance report within 90 days.
- Dental offices that undergo a transfer of ownership must file a one-time compliance report within 90 days of the transfer.
Dental offices that place or remove amalgam must operate and maintain a compliant amalgam separator and must not discharge scrap amalgam or use oxidizing or acidic drain line cleaners (e.g. bleach, chlorine, iodine, peroxide that has a pH <6 or >8) which may cause mercury to leach from the separators into the wastewater entering the sewer system. For more information please visit EPA’s website and the forms below.