Dental Amalgam | City of Bloomington, Indiana

Page last updated on March 4, 2026 at 2:17 pm

Background on the Dental Rule

The “Dental Rule,” established by the United States Environmental Protection Agency (EPA) went into effect on July 14, 2017. The purpose of this rule is to significantly reduce the discharge of mercury from dental facilities into municipal sewer systems and, ultimately, the environment. Dental facilities that place or remove dental amalgam in fillings are required to install amalgam separators to capture the amalgam before it is released to the sewer.

The Dental Rule is part of the EPA’s General Pretreatment Regulations, which fall under the Clean Water Act. The City of Bloomington Utilities (CBU) Pretreatment Program enforces the Dental Rule and is working to help local dental facilities understand the rule. CBU previously sent a letter of explanation and survey to all types of dental practices that discharge to the city’s sewers. After exploring practices and equipment in each facility, CBU determines if the facility is subject to the new rule. CBU then works with each facility to assure their compliance with the rule. All new or remodeling dental facilities, or transfer of ownerships should notify CBU immediately.

New dental facilities which begin discharging to the sewer after July 14, 2017 must comply immediately with the standards in the rule and complete CBU’s One Time Compliance Report within 90 days of discharge.

Existing dental facilities that began discharging to the sewer on or before July 14, 2017 must submit plumbing plans for the amalgam separator by July 1, 2019, install, operate, and maintain an amalgam separator by July 14, 2020, and complete CBU’s One Time Compliance Report by October 12, 2020.

New Source Requirements

Plan Requirements:

Submit two hard copies of plumbing plans that include layout, placement, fixtures, and scale to the City of Bloomington Utilities (CBU) for installation approval.
Contact the Monroe County Building Department for permits and requirements on proper installation.

Before introduction of wastewater into the sanitary sewer system:

Install, operate, and maintain one or more amalgam separators meeting the requirements:
- ISO Standard: 11143 or comparable version with at least a 95% removal efficiency.
- Sized appropriately to accommodate for the maximum discharge rate.
- Must be inspected and maintained as often as described in the manufacturing operations manual to confirm that all amalgam process wastewater is flowing and the separator is working properly.
- Separator must be repaired or replaced within 10 days of malfunction discovery.
Implement required best management practices (BMPs):
- Waste amalgam from chair-side traps, screens, vacuum, dental tool, collection devices, etc. may not be discharged into the sanitary sewer system.
- Oxidizing or Acidic cleaners with a pH lower than 6 or greater than 8 may not be used in water lines, chair-side traps, or vacuum lines.

Must comply with the following reporting requirements:

Submit a onetime compliance report, provided by CBU, within 90 days of introduction of wastewater.
- Compliance report will include: facility name, physical address, mailing address, contact information, name of the owner(s)/operator(s), total number of chairs, number of chairs in which dental amalgam could contaminate wastewater, description of amalgam separator including the make, model, and year of installation, certification that the device will be properly monitored and maintained, certification that BMPs will be upheld, and the name of the third-party service provider that operates and maintains including clean outs.
Maintain readily available log records for a minimum of three years. Log forms provided by CBU.
- Cleaning Log to document all dates that dental amalgam is picked up or shipped for proper disposal.
  - Includes: date, time, cleaned by, witnessed by, estimated volume removed, waste disposal location, comments, and date shipped.
- Repair and Replace Log to document container replacement, or any repairs or replacing of the amalgam separator itself.
  - Includes: date, person making repair or replacement, description of repair or replacement, and amalgam separator make and model.
- Inspection Log to document the inspection and the result of the inspections.
  - Includes: date, name of inspector, result of inspection, and follow up summary.

Existing Source Requirements

Plan Requirements:

Submit two hard copies of plumbing plans that include layout, placement, fixtures, and scale to the City of Bloomington Utilities (CBU) for installation approval no later than July 1, 2019.
Contact the Monroe County Building Department for permits and requirements on proper installation.

By July 14, 2020:

Install, operate, and maintain one or more amalgam separators meeting the requirements:
- ISO Standard: 11143 or comparable version with at least a 95% removal efficiency.
- Sized appropriately to accommodate for the maximum discharge rate.
- Must be inspected and maintained as often as described in the manufacturing operations manual to confirm that all amalgam process wastewater is flowing and the separator is working properly.
- Separator must be repaired or replaced within 10 days of malfunction discovery.
Implement required best management practices (BMPs):
- Waste amalgam from chair-side traps, screens, vacuum, dental tools, collection devices, etc. may not be discharged into the sanitary sewer system.
- Oxidizing or Acidic cleaners with a pH lower than 6 or greater than 8 may not be used in water lines, chair-side traps, or vacuum lines.

Must comply with the following reporting requirements:

Submit a onetime compliance report, provided by CBU, by October 12, 2020 or 90 days after transfer of ownership.
- Compliance report will include: facility name, physical address, mailing address, contact information, name of the owner(s)/operator(s), total number of chairs, number of chairs in which dental amalgam could contaminate wastewater, description of amalgam separator including the make, model, and year of installation, certification that the device will be properly monitored and maintained, certification that BMPs will be upheld, and the name of the third-party service provider that operates and maintains including clean outs.
Maintain readily available log records for a minimum of three years. Log forms provided by CBU.
- Cleaning Log to document all dates that dental amalgam is picked up or shipped for proper disposal.
  - Includes: date, time, cleaned by, witnessed by, estimated volume removed, waste disposal location, comments, and date shipped.
- Repair and Replace Log to document container replacement, or any repairs or replacing of the amalgam separator itself.
  - Includes: date, person making repair or replacement, description of repair or replacement, and amalgam separator make and model.
- Inspection Log to document the inspection and the result of the inspections.
  - Includes: date, name of inspector, result of inspection, and follow up summary.

Resources:

For more information visit the EPA Dental Guidelines or contact CBU’s Pretreatment Coordinator at 812-349-3946.