Dental Amalgam Wastewater Compliance Program

In 2017, the Environmental Protection Agency finalized its Dental Effluent Guidelines (40 CFR 441) to reduce discharges of mercury from dental offices to municipal sewage treatment plants. The ruling came into effect on July 14, 2017. Compliance was date-specific and required adherence to certain specified Best Management Practices (BMPs). Dental facilities that were in existence prior to July 14, 2017 had until July 14, 2020 to comply, while facilities that started operations after the ruling took effect are required to comply immediately. 

Rancho California Water District (Rancho Water/District) operates the Santa Rosa Water Reclamation Facility, which treats wastewater collected from residential, industrial, and commercial customers within the city of Murrieta, portions of the city of Temecula, and unincorporated Riverside County.

Rancho Water’s Dental Amalgam Compliance Program applies to facilities within its sewer service area. Click here to find out if you are within Rancho Water’s service area. Type in the physical address of your dental facility; if your facility shows within Rancho Water’s service area, your facility is part of Rancho Water’s Dental Compliance Program and is required to submit a One-Time Compliance Report to the District. Use only the form provided on this website; the EPA form does not include California-specific requirements; therefore, should not be used.

Please direct all inquiries about Rancho Water’s Dental Amalgam Compliance Program to (951) 296-6985 or email us.  

Program Details


All dental facilities that place or remove dental amalgam as part of their practices will need to comply with this rule (i.e., must install an approved amalgam separator and submit the One-Time Compliance Report by the respective due dates).

Facilities that place or remove dental amalgam ONLY in limited emergency or unplanned, unanticipated circumstances are not required to have an approved dental amalgam separator, but must certify that that their discharge occur only in limited circumstances.

The following facilities are not anticipated to discharge dental amalgam in its wastewater and are exempt from this rule:

  • Facilities that exclusively practice one or more of the following dental specialties: oral pathology, oral and maxillofacial radiology, oral and maxillofacial surgery, orthodontics, periodontics, and/or prosthodontics.
  • Facilities that do not discharge dental amalgam processed wastewater to the sewer system. In such facilities, dental amalgam processed wastewater is typically collected and transferred to a Centralized Waste Treatment Facility
  • Facilities that operate solely from a mobile unit.

If your facility falls in any of the three categories above, you do not have to submit a form AND are not required to install a dental amalgam separator.

Compliance Requirements

Install an appropriately sized dental amalgam separator that is compliant with either of the following:

  • American National Standards Institute (ANSI) American National Standard/American Dental Association (ADA) Specification 108 for Amalgam Separators (2009) with Technical Addendum (2011) with a minimum removal efficiency of 95%
  • International Organization for Standardization (ISO) 11143 Standard (2008) or subsequent versions with a minimum removal efficiency of 95% removal
  • An equivalent device that meets the requirements of CFR 441.30 (2)

Implement the BMPs outlined in 40 CFR 441.30(a) and (b).

Compliance Dates

See the table below to determine your compliance dates.

Comply by

Submit Form by

Dental facilities that were in existence before July  14, 2017 and have not had a change of ownership

July 14, 2020

October 12, 2020

Dental facilities that began operating before July 14, 2017 and have had a change of ownership since then

Immediately or provide proof of compliance

90 days of ownership change

Dental facilities that opened after or have had a change of ownership since  July 14, 2017


90 days after discharging

Submit periodic monitoring report to Rancho California Water District

Annually (by October 12th of each year)

Recordkeeping Requirements

  • Facilities are required to maintain the One-Time Compliance Report as long as the practice is in business or until ownership is transferred
  • Maintain maintenance and inspection records for a minimum of 3 years
  • Following the recordkeeping requirements outlined in 40 CFR 441.50


The following resources are intended to assist you in complying with the Dental Effluent Guidelines, and provide information on best management practices for handling your waste amalgam.

One-Time Compliance Report (pdf)

Rancho Water Dental Amalgam Flyer (pdf)

EPA Dental Effluent Guidelines

EPA Frequently Asked Questions on the Dental Category Rule

California Dental Association Amalgam Waste Management Practices

Frequently Asked Questions (pdf)