Pretreatment Requirements for Industrial Users

What Is a "Significant Industrial User"?

A significant industrial user is defined as:

• An industrial user subject to categorical pretreatment standards, known as a categorical industrial user (CIU).

• Any other industrial user that:

• discharges 25,000 gallons per day or more of process wastewater to the publicly owned treatment works (POTW) (excluding sanitary, noncontact-cooling, and boiler-blowdown wastewater)

• contributes process wastewater to the POTW which makes up 5 % or more of the average dry-weather hydraulic capacity of the wastewater treatment plant

• contributes process wastewater to the POTW which makes up 5 % or more of the organic capacity of the wastewater treatment plant

• or is designated as such by the POTW because the industrial user has a reasonable potential for adversely affecting the wastewater treatment plant's operations and sewer system or for violating any pretreatment requirement

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What Is a "Categorical Industrial User"?

A categorical industrial user is a facility that meets these conditions:

• The industrial activity performed at the facility is regulated by one or more of the federal regulations found in Title 40, Code of Federal Regulations (40 CFR) Parts 400 - 424 425 - 699

• The facility discharges process wastewater to a publicly owned treatment works

• In the EPA Pretreatment Categories and Standards, the categorical activity is assigned pretreatment limitations, reporting requirements, or both.

If you are a CIU, you must comply with the categorical pretreatment standards specified in the federal regulations and any local limits established by the POTW that receives your wastewater discharges.

For additional information on industrial categories and reporting requirements for CIUs, see Reporting Requirements for Categorical Industrial Users.

To determine whether you are a CIU, please submit a "categorical determination request" to the TCEQ. The requirements are listed in 40 CFR 403.6. Submit your request to:

• Pretreatment Team MC-148
• Water Quality Division, TCEQ
• P.O. Box 13087
• Austin, Texas 78711-3087

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Is Your Wastewater Discharge Regulated by Your Local POTW or TCEQ?

If you are a categorical industrial user (CIU) discharging process wastewater to a publicly owned treatment works

If you are a significant industrial user not subject to federal categorical pretreatment standards, you may still be regulated by your local POTW.

To determine who is responsible for regulating your wastewater discharges to the POTW you will need to know:

• Does the POTW have an approved pretreatment program?

• See our list of approved TPDES Pretreatment Programs to find out.

• If the POTW does not have an approved pretreatment program, does the POTW have local requirements for industries or facilities discharging wastewater to their system?

• Contact the local municipality who owns the POTW to find out if they have any requirements for facilities discharging to the sanitary sewer system.

Contact the Pretreatment Program if you have questions.

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