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Technically Based Local Limits for Wastewater Discharges from POTWs

Definition of technically based local limits for publicly owned treatment works and who needs them. Find forms and requirements for how to develop TBLLs, get them approved, and reassess them.

What Are "Local Limits"?

Technically based local limits, also referred to as local limits, are wastewater limitations that apply to commercial and industrial facilities that discharge to a publicly owned treatment works (POTW)Exit the TCEQ.40 CFR 403.5(d)Exit the TCEQ.

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Who Needs to Develop Local Limits?

The following POTWs are required by 40 CFR 403.5(c)Exit the TCEQ to develop local limits:

    • POTWs required to implement an approved pretreatment program need to develop local limits, or demonstrate that they are not necessary

    • Other POTWs where wastewater discharges from commercial and industrial facilities have caused interference or pass through, and such violation is likely to recur

This requirement is contained in the POTW’s Texas Pollutant Discharge Elimination System (TPDES) permit.

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How to Develop Local Limits

Submit this sampling plan checklistMicrosoft Word Document at least 30 days prior to conducting a study of the local limits your POTW may need.

Follow these steps to develop local limits:

    1. Determine pollutants of concern.

    2. Collect and analyze wastewater data.

    3. Calculate maximum allowable headworks loadings to the wastewater treatment plant.

    4. Calculate maximum allowable industrial loadings.

    5. Allocate the resulting TBLLs.

    These Environmental Protection Agency (EPA) guidance documents show how to complete each step:

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    Getting Local Limits Approved

    Guide for TBLLs Submittal and Pretreatment Program Package Adobe Acrobat PDF Document lists the items you will need to submit for approval to the TCEQ's Pretreatment Program.

    The relevant rule for this approval process is 40 CFR Section 403.18.Exit the TCEQ

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    When You May Need to Reassess Your Local Limits

    Consider reassessing your local limits if any of these conditions arise:

        • Your POTW expands

        • New commercial or industrial customers connect to your system

        • Existing commercial or industrial customers disconnect from your system

        • Your options for handling sewage sludge change

        • Monitoring data shows noteworthy variations of pollutants of concern from previous levels in your POTW's influent, effluent, or both

    If you are not certain whether your adopted local limits need to be revised, complete the TBLLs Reassessment Form (TCEQ-20221).Adobe Acrobat PDF Document In completing the form you may recognize situations that call for revisions.

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    When You are Required to Reassess Your Local Limits

    If you have an approved pretreatment program, within 60 days after your TPDES permit is issued, renewed, or amended, you must reassess your existing limits. Your permit will contain one of these options.

    If you have reassessed your local limits and can demonstrate that the existing limits are protecting your POTW and receiving stream:

        • Submit a completed TBLLs Reassessment Form (TCEQ-20221).Adobe Acrobat PDF Document

        • Have your POTW's authorized representative sign the certification statement on the form.

        • Submit the form to the TCEQ Pretreatment Program.

    If you will be developing new local limits for review and approval within 12 months of the date the permit was issued:

        • You may notify us with a letter or with a completed TBLLs Reassessment Form.

          • If you notify by letter, you must enclose a certification statement that is signed by your POTW's authorized representative.

          • If you submit a completed TBLLs Reassessment Form (TCEQ-20221),Adobe Acrobat PDF Document the certification statement on the form must be signed by your POTW's authorized representative.

          • Submit any new or revised local limits and any necessary supporting documents no more than one year from the date the permit was issued.

    For either option, submit all documentation, forms, letters or any other required certification to:

      • Texas Commission on Environmental Quality
      • Water Quality Division
      • Wastewater Permitting Section
      • Pretreatment Team MC-148
      • P.O. Box 13087
      • Austin TX 78711-3087

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