Industrial Pretreatment

Any industrial facility who discharges process wastewater to a publicly owned treatment works (POTW) and is classified as a significant industrial user must obtain a pretreatment permit. Any POTW that receives process wastewater may implement an EPD approved local pretreatment program, and issue local pretreatment permits.

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Pretreatment permits are designed to protect a POTW infrastructure and reduce conventional and toxic pollutant levels discharged by industries to a POTW and into the environment. These permits may be issued by the State or a POTW depending on whether the POTW has an approved pretreatment program. Pretreatment standards and requirements include general and specific prohibitions, categorical pretreatment standards, and local limits. POTWs with an EPD approved Pretreatment Program are responsible for the issuance, compliance, inspections, and enforcement of all pretreatment permits that discharge to their POTW(s). The Environmental Protection Division is the issuing authority for pretreatment permits in cases where there is not an approved local Pretreatment Program. A POTW with a design greater than 5 MGD is required to have an approved Pretreatment Program (40 CFR 403.8).

Download this pdf file. A list of approved Pretreatment Programs within the State may be found here .

EPD Pretreatment Permits

A pretreatment permit is required for any industrial user who discharges process wastewater to a POTW and is classified as a significant industrial user. A significant industrial user falls under at least one of the following categories, as defined in 40 CFR 403:

  • Industrial user subject to Categorical Pretreatment Standards
  • Discharges an average of 25,000 gallons per day or more of process wastewater to the POTW
  • Contributes a process waste-stream which makes up 5% or more of the POTW capacity
  • Designated by the control authority based on reasonable potential for adversely affecting the POTW’s operation or for violating a pretreatment standard

Pretreatment Permit Process


To ensure the timely renewal of a permit, please ensure that a complete application is submitted a minimum of 180 days before permit expiration.

Electronic permit applications and forms can be found here.

Permit Requirements

Upon the effective date of the permit, the facility is required to comply with all of the requirements of the permit. The permittee should carefully review their permit before it is issued to ensure all of the requirements are understood, such as: the identified monitoring locations, monitoring and reporting frequencies, parameters required for monitoring, and effluent limitations. The conditions listed below define some of the components that may be included in a Pretreatment Permit.

For more specific information on permit conditions and reporting conditions, please visit the corresponding links. Additional information is also available for special conditions and reasonable potential analyses


Pretreatment Program

Upon EPD delegation, any POTW that receives process wastewater may implement a Local Pretreatment Program. POTWs that meet the following criteria may be required by EPD to implement an Industrial Pretreatment Program:

  • A facility with a design flow greater than 5 MGD accepting industrial process wastewater
  • A facility with a design flow less than 5 MGD if the nature or volume of the industrial influent warrants a program
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The National Pretreatment Program identifies specific discharge standards and requirements that apply to sources of nondomestic wastewater discharged to a POTW. Pretreatment standards and requirements include general and specific prohibitions, categorical pretreatment standards, and local limits. Pretreatment regulations allow EPD to delegate the responsibility of issuing and enforcing pretreatment permits to a local control authority upon approval of the program.

Program Approval Process

The process for obtaining an approved pretreatment program may be found to the left. Unlike a permit, a program does not include an expiration date.

Program Requirements

Upon the approval of a pretreatment program, the program shall be enforceable through the POTW’s NPDES or LAS permit(s). Under the permit(s) the facility shall be required, at a minimum, to complete and submit an annual report defining the activities and contributions of any industrial users. Forms required as a part of the annual report can be found here.

If at any time after a program is approved and the control authority wishes to modify their program, requests may be made in writing to EPD. Any changes approved by EPD may require a public notice period for the modified program.

For more information, additional guidance documents on the pretreatment process may be found here

Dental Amalgam Rule

Effluent Limitations Guidelines and Standards for Dental Offices 

EPA finalized technology-based pretreatment standards under the Clean Water Act to reduce discharges of mercury and other metals from dental offices into municipal sewage treatment plants known as Publically Owned Treatment Works (POTWs). The Dental Office Category regulation is codified at 40 CFR Part 441. The final rule, effective July 14, 2017, requires dental office to control the discharge of mercury and other metals in dental amalgam discharged to POTWs based on the best available technology or best available demonstrated technology. The requirements are based on the use of amalgam separators and best management practices recommended by the American Dental Association (ADA). In addition, this rule also minimizes dental office reporting requirements and the administrative burden to Federal, State and Local regulatory authorities for oversight of the new requirements.

This rule applies to dental offices, dental schools and clinics, where dentistry is performed and wastewater is discharged to POTWs. It does not apply to wastewater discharges from mobile units or forces where the practice of dentistry consists exclusively of the following specialties: oral and maxillofacial radiology, oral and maxillofacial surgery, orthodontics, periodontics, or prosthodontics.


Dental Offices that place or remove amalgam must operate and maintain an amalgam separator and must not discharge scrap amalgam or use certain kinds of line cleaners. The compliance date for new dental offices (‘New Source’) is July 14, 2017. Existing dental offices (‘Existing Source’) must comply with the rule by July 14, 2020. Existing amalgam separators can be operated for their lifetime or ten years, whichever comes first. When a separator needs replacement, or the ten-year period has ended and the separator does not meet the standard of the final rule, a dental office must replace it with one that meets the requirements of the rule.

Best Management Practices

  1. Prohibit use of oxidizing line cleaners including but not limited to, bleach, chlorine, iodine and peroxide, that have a pH lower than 6 or greater than 8
  2. Prohibit flushing waste dental amalgam into any drain

Reporting and Recordkeeping Requirements

Dental Offices that discharge to POTWs must submit a One-Time Compliance report to the Control Authority. Existing sources must submit the report by October 12, 2020 or if this date has been reached, 90 days after a transfer of ownership. New Sources must submit it within 90 days after their first discharge. If your Control Authority is the State, please use the form below.

Download this doc file. GA EPD Dental Rule One-Time Compliance Form

The rule also requires dental offices to document operation and maintenance requirements, inspections and any repairs or replacements of an amalgam separator or an equivalent device. The dental office should also maintain compliance records and manufacturer’s operating manual for the device in place and make the records available for inspection, for a minimum of three years.

Control Authority Oversight

The rule requires that the Control Authority must receive the  Download this doc file. One-Time Compliance report  from dental dischargers and retain that notification according to the standard records retention protocol contained in 403.12(o).

You can find information on the rule, including a copy of the Federal Register notice, on EPA’s Effluent Guidelines website at: The final rule is also available at under Docket ID: EPA-HQ-OW-2014-0693.

EPD is currently working on FAQs for dental offices and Control Authorities.