Managing mercury in dental wastewater

Mercury is a toxic heavy metal that is used in amalgam form for dental fillings. Dental wastewater may be contaminated with mercury any time dentists work on teeth containing mercury amalgam fillings, even if the dentist is not placing new mercury amalgam fillings themselves. All dentists in Minnesota must meet federal and state requirements to limit the amount of mercury in their wastewater. The Minnesota Pollution Control Agency (MPCA) administers these requirements in Minnesota.

Install and use an appropriate amalgam separator

All dentists in Minnesota that perform any work on teeth containing mercury amalgam fillings must either install and use an appropriate amalgam separator or collect their dental chair wastewater separately and manage it as a hazardous waste. The chart below summarizes what types of amalgam separators must be installed and when.

If your dental facility is: Then you:

Not connected to a public sanitary sewer (is on a septic system)

may NOT discharge dental wastewater to your septic system.

must either:

Located in the Minneapolis-St. Paul Metropolitan Area and connected to a public sanitary sewer served by Metropolitan Council Environmental Services (MCES)*

must install and use an MPCA-approved amalgam separator.

*Find out if your dental facility is served by MCES: PDF icon Communities served by a delegated POTW (wq-wwtp7-49b)

Located outside the Minneapolis-St. Paul Metropolitan Area or is connected to any other public sewage treatment system except MCES

must install at least a federally compliant amalgam separator by July 14, 2020**, unless your sewage treatment plant operator requires you to install an MPCA-approved amalgam separator.

**If your facility already has installed another amalgam separator, you have until June 14, 2027, to replace it with at least a federally compliant separator, unless otherwise required by your sewage treatment plant operator.

To protect Minnesota’s waters, the MPCA and Minnesota Dental Association (MDA) agreed in their 2007 written Memorandum of Understanding (MOU) that all Minnesota dentists are strongly encouraged to install MPCA-approved amalgam separators.

MPCA-approved amalgam separators

The MPCA, in partnership with MCES and the MDA, has approved these amalgam separators. All of these separators surpass the U.S. Environmental Protection Agency’s (EPA) minimum federal requirements.

To maintain the approval of their installed amalgam separators, dentists must follow the manufacturer’s operating and maintenance instructions and use only suction line cleaners compatible with the installed separator.

Manufacturers and distributors interested in submitting amalgam separators for review and approval by the MPCA may contact the MPCA for performance criteria and application procedures.

Amalgam separator Manufacturer/distributor Notes
Amalgam HoG DentalEZ Group, branded as RAMVAC 1
amalsed Silver Medentex 1
AVTMax Apavia Filtration Technologies 1
CatchHg 400 Rebec Environmental  
CatchHg 1000 Rebec Environmental 2
ECO II Metasys Group; distributed by
Pure Water Development LLC dba Pureway Total Compliance
 
ECO-STAR Tech West Inc. 1
Hg5-001K
  with CC-5M collection container
Solmetex; also branded as RAMVAC 3
Hg5-HV
  with CC-5M collection containers
Solmetex 3
Hg5-Mini
  with CC-5M collection container
Solmetex 3
LibertyBOSS MARS Bio-Med Processes, Inc  
NXT-Hg5-001
  with NXT-Hg5 collection container
Solmetex  
NXT-Hg5-HV
  with NXT-Hg5 collection container
Solmetex  
Syclone Crosstex 1

Notes:        

  1. The Syclone Crosstex model line previously sold by Crosstex, and also rebranded as the Amalgam HoG, amalsed Silver, AVTMax, and ECO-STAR, has been purchased by Solmetex. Solmetex is discontinuing the model line and offering replacement with Solmetex NXT Hg5 models. Contact Solmetex or your distributor for additional information.
  2. Custom systems designed by the manufacturer based on the CatchHg 1000 are also approved.
  3. The Hg5 model line is no longer available, but may continue to be used with the CC-5M collection containers. The Hg5 model line was also offered by DentalEZ under the RAMVAC brand name; these may also continue to be used with the CC-5M or RAMVAC-branded collection containers sold by Solmetex.

To maintain the approval of their installed amalgam separators, dentists must follow the manufacturer’s operating and maintenance instructions and use only suction line cleaners compatible with the installed separator.

Manufacturers and distributors interested in submitting amalgam separators for review and approval by the MPCA may contact the MPCA for performance criteria and application procedures.

Federally compliant amalgam separators

All amalgam separators installed in Minnesota must at least meet the minimum federal requirements in the U.S. Environmental Protection Agency’s (EPA) Dental Office Point Source Category regulations, found in the Code of Federal Regulations, Title 40, Part 441.

All MPCA-approved amalgam separators surpass the minimum federal requirements, however the MPCA does not review other amalgam separators for compliance with the federal minimum standard. For questions on the minimum federal standard, contact the EPA.

Submit certification/compliance report

All dentists in Minnesota must submit either a certification or compliance report to the designated control authority for their facility’s community. To find your community’s designated control authority, refer to the list of delegated POTWs (publicly owned treatment works): PDF icon Communities served by a delegated POTW (wq-wwtp7-49b)

If your facility’s community is delegated or serviced by MCES, contact them to determine how to submit your certification or compliance report.

If your facility’s community is not listed, the designated control authority is the MPCA. Submit your certification or compliance report:

  • via e-mail: dental.mpca@state.mn.us
  • or mail: MPCA, Attn: WQ Submittal Center; 520 Lafayette Rd N; St. Paul, MN  55155-4194

Initial certifications or compliance reports must be submitted by October 12, 2020.

Subsequent certifications or compliance reports must be submitted within 90 days of a change of ownership of a dental facility or after installation or replacement of an amalgam separator.

Submit certifications and compliance reports (Instructions are included on the form): Microsoft Office document icon One-time dental certification/compliance report (wq-wwtp7-49a)

Related wastes and regulatory questions

Mercury amalgam scraps and sludge collected in amalgam separator collection containers may be managed equivalent to a universal waste in Minnesota: PDF icon Managing universal wastes (w-hw4-62)

Dental facilities often generate other regulated wastes, including pharmaceuticals and sharps: PDF icon Regulatory consensus on health care issues (w-hw3-35)

For questions regarding mercury amalgam separators, separator approval, or certification or compliance reports, contact the MPCA at dental.mpca@state.mn.us.