Dental Amalgam Rule

Dental Effluent Guidelines

Facilities that practice dentistry are the main source of mercury discharges to municipal sewer systems. The US EPA promulgated regulations to reduce discharges of mercury from dental offices. The specific requirements are described in 40 CFR Part 441, Dental Office Point Source Category, and are summarized below:

Dental Offices Affected by the Regulations

All dental offices where the practice of dentistry is performed, including, but not limited to, institutions, permanent or temporary offices, clinics, home offices, and facilities owned and operated by Federal, state or local governments, that discharge wastewater to a municipal sewer system (referred to as a publicly owned treatment works or POTW) are affected by these regulations. These facilities are referred to as Dental Dischargers.

Existing Dental Dischargers: Dental offices that began discharging prior to July 14, 2017.
New Dental Dischargers: Dental offices that began discharging after July 14, 2017.

One-Time Compliance Report

All Dental Dischargers, even dental offices that do not discharge amalgam process wastewater, must submit a One-Time Compliance Report.

Existing Dental Dischargers: The deadline for submitting a report for an existing dental discharger is October 12, 2020.
New Dental Dischargers: A report must be submitted no later than 90 days following the discharge to the sewer.

The report must be sent to the local municipal sewer system with an approved pretreatment program.

Requirements for Dental Offices that Discharge Amalgam Process Wastewater

An amalgam separator must be installed, operated and maintained, and a One-Time Compliance Report must be submitted.
Waste amalgam including, but not limited to, dental amalgam from chair-side traps, screens, vacuum pump filters, dental tools, cuspidors, or collection devices, must not be discharged to a municipal sewer system.
Dental unit water lines, chair-side traps, and vacuum lines that discharge amalgam process wastewater to a POTW must not be cleaned with oxidizing or acidic cleaners, including, but not limited, to bleach, chlorine, iodine and peroxide that have a pH lower than 6 or greater than 8.
Specific requirements are described in 40 CFR Part 441.

Control Authority

The term Control Authority, used in the regulation, refers to the municipal sewer system with an approved pretreatment program. In some cases a dental office is located outside of a municipal sewer system area with an approved pretreatment program. If that is the case, the One-Time Compliance Report must be submitted to the Division of Water.

Dental Amalgam Rule Federal Register Dental Effluent Guidelines (EPA)40 CFR Part 441Dental Office Point Source Category

For more information contact:

SWPBSupport@ky.gov

​​​​​​​​​​​Dental Effluent Guidelines

Dental Effluent Guidelines