Wastewater Pretreatment

Pretreatment Program

The City of Nacogdoches (City) Pretreatment Program administers local, state and federal regulations to control the discharge of pollutants from commercial and industrial users within the City, which may pass through or interfere with the City’s wastewater treatment plant. 

The Pretreatment Program protects the wastewater treatment process and keeps costs down by working with local businesses to minimize pollutant discharges. Activities of the City’s Pretreatment Program include issuance of permits, facility inspections, monitoring of facilities (wastewater sample collection), review of industry self-monitoring reports, and enforcement actions. 

Modified Industrial Pretreatment Program - enacted date:  April 27, 2021

Pretreatment Program - Technically Based Local Limits (TBLL)

The City of Nacogdoches is proposing to amend the Technically Based Local limits (TBLL) within the Pretreatment Program.

The Pretreatment Team of the Texas Commission on Environmental Quality (TCEQ) has performed the review of the City of Nacogdoches, hereinafter referred to as the Control Authority (CA), pretreatment program’s Technically Based Local Limits (TBLLs) Redevelopment package.

The proposed substantial modification package was originally submitted on March 12, 2012. Revisions and additional documentation were submitted to the TCEQ on August 10, 2016; September 10, 2021; and July 11, 2023. The TCEQ has determined that this substantial program modification is technically complete, and the TCEQ is in agreement with the City of Nacogdoches on the proposed TBLLs for the Nacogdoches Plant 2A Wastewater Treatment Facility (WWTF), as shown in the table below:

Pollutant of Concern

TBLLs Proposed by the CA and Accepted by the TCEQ (mg/L)
Uniform Allocation
Tiered Flow <1 MGD
Tiered Flow >1 MGD


Chromium, Total2.26


Cyanide, Total0.06






The binding criteria set forth by the TCEQ include:

  • The CA will adopt the proposed limit.
  • The CA will not revise the TBLL for copper and will maintain the current TBLL of 0.9 mg/L. The average copper loading at the headworks between the years 2018-2021 is less than 35% of the MAHL calculated from the current TexTox copper limit. The current TBLL will remain until a study to determine a site-specific copper water quality standard for the WWTP discharge and the redevelopment of an appropriate copper TBLL is completed.
  • The CA submitted a non-substantial modification on August 5, 2022, to reallocate the maximum allowable industrial loading for lead based on recently updated industrial user information. The TCEQ accepted the proposed tiered flow limits for lead on September 14, 2022.

The City of Nacogdoches is required to publish a public notice during the permit action in order to incorporate the substantial program modification into the permit, as specified in 40 CFR Part 403.11 and 403.18. Once the substantial modification is approved, it will be incorporated into the City of Nacogdoches pretreatment program upon issuance of the next TPDES permit action.

Please view the proposed TBLL amendments below:

City of Nacogdoches TBLL Calculation Report (2023)

Sewer Use Regulations

Nac. Sec. 3b Enforcement Response Guide

SIU Permit Revisions

MIU Permit Revisions

Cross-Connection and Backflow Prevention Program

Backflow is the undesirable reversal in a potable water distribution system. A Cross-Connection is a connection between a potable drinking water supply and a possible source of contamination or pollution. The City of Nacogdoches Cross-Connection and Backflow Prevention Program is responsible for protecting the City’s public water supply by regulating the installation, testing, re-testing and certification of testable backflow prevention assemblies and certified backflow assembly testers. 

The City has contracted with SC Tracking Solutions (SC) to administer our cross-connection control/backflow tracking program. The City uses SC online for all initial and annual test report submissions. 

Need a list of Registered Backflow Testers approved by the City?

At the bottom of the webpage click on "NEED A SERVICE PROVIDER?"