Pretreatment Program

Frequently Asked Questions​

​Pretreatment Program

What is pretreatment?

Pretreatment is the reduction, the elimination, or the alteration of pollutants in wastewater to a less harmful state prior to discharge of the wastewater to a sanitary sewer system.
The term "pretreatment" refers to the requirement that non-domestic sources control their wastewater before discharge to meet all applicable pretreatment standards and requirements (federal, state and local). 

What is a pretreatment program?

It is an EPA-mandated program (40 CFR 403) that requires the Dallas Water Utilities (DWU) to regulate industrial and other non-domestic wastewater sources that discharge into DWU's wastewater collection system, thereby reducing the amount of pollutants released into the environment from the DWU's treatment plants. The purpose of the program is to:

  • Protect the collection system and treatment plant infrastructure from physical damage from non-domestic pollutants.
  • Protect treatment plant processes from harmful pollutants that could interfere with those processes.
  • Protect the Trinity River from non-domestic pollutants that could pass through the plant untreated.
  • Ensure that the DWU's biosolids comply with disposal requirements.
  • Protect DWU employees from potentially harmful chemicals.

Why does the DWU have a pretreatment program?

The Clean Water Act established the responsibility for Federal, State, and local government to implement National Pretreatment Standards in order to control pollutants from non-domestic sources that discharge to a Publicly Owned Treatment Works (POTWs). DWU operates 2 wastewater treatment plants that treat wastewater from domestic and industrial sources. These plants in turn discharge treated wastewater to the Trinity River. Each of DWU's treatment plants holds a permit issued by the Texas Commission on Environmental Quality (TCEQ). These permits regulate DWU's plant effluent discharges to the Trinity River. Each permit contains requirements to implement a pretreatment program to prevent pollution of the waterways.

What types of industrial users are regulated under the pretreatment program?

All industrial users located within the City of Dallas' jurisdiction must comply with DWU's Pretreatment Regulations. However, industrial users that perform processes deemed "categorical" by the EPA and/or significant by DWU, must comply with additional requirements.

What is a Significant Industrial User?

The term Significant Industrial User (SIU) as defined by the EPA means: (1) All industrial users subject to Categorical Pretreatment Standards under 40 CFR 403.6; and (2) Any other industrial user that: discharges an average of 25,000 gallons per day or more of process wastestream, which makes up 5 percent or more of the average dry weather hydraulic or organic capacity of the treatment plant; or is designated as a SIU by DWU on the basis that the industrial user has a reasonable potential for adversely affecting the operation of DWU's wastewater treatment plants.

When are Industrial Users required to obtain a permit?

Potential SIUs under construction should apply for a DWU Discharge Authorization Permit at least 90 days prior to discharging to the DWU's sanitary sewer. Existing SIUs should apply as soon as possible.

How do I obtain a permit for my company?

To obtain a DWU Discharge Authorization Permit you must complete a DWU Non-Residential Customer Questionnaire form and submit it to this office. If your industry meets the definition of a Significant Industrial User, you will be required to complete and submit a DWU Industrial Waste Discharge Permit Application to the Pretreatment and Laboratory Services Division .

What happens if an Industrial User does not comply with pretreatment program requirements?

If an Industrial User does not comply with pretreatment program requirements, it will be subject to enforcement action in accordance with the guidelines established in DWU's Enforcement Response Plan.

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