Pretreatment

The Pretreatment Program is a requirement of the Texas Pollutant Discharge Elimination System (TPDES) discharge permit for each of the SAWS wastewater recycling centers. It is a method to control the pollutants discharged into sanitary sewer systems and used to reduce the amount of pollutants released into the environment.

warehouseWastewater from homes, commercial buildings, and industrial facilities is collected and transported through the sanitary sewer collection system to one of the regional wastewater treatment plants. These plants remove harmful organisms and contaminants from the wastewater before discharge into the receiving river.

SAWS wastewater recycling centers are designed to treat domestic wastes from households but do not to treat toxic pollutants from industrial or commercial facilities. The toxic pollutants from industrial and commercial facilities may cause serious problems at publicly owned treatment works that use biological treatment. Problems may be prevented by recycling, waste minimization, chemical substitution, pretreatment, or other best management practices to reduce or eliminate the pollutants from commercial or industrial facilities.

treatment workerThe U.S. Environmental Protection Agency (EPA) developed the General Pretreatment Regulations under 40 CFR Part 403 to set responsibilities for federal, state and local governments, industry and the public to achieve the National Pretreatment Program objectives. The EPA describes this national program in its “Introduction to the National Pretreatment Program” (pdf).

The General Pretreatment regulations listed in 40 CFR Part 403 are integrated into the TCEQ approved Pretreatment Program and are incorporated into the City of San Antonio City Code in Chapter 34 Waters & Sewer, Article V. Sewage Transportation, Treatment and Disposal, Division 3 Industrial Waste. These codes also include “Technically Based Local Limits” which are derived from calculations to determine the maximum levels for specific pollutants for nonresidential users (includes commercial and SIU facilities).

 

Technically Based Local Limits: [34.472(4)(b)]

0.7 mg/L

Arsenic

5.0 mg/L

Chromium

0.17 mg/L

Total Cyanide

0.05 mg/L

Mercury

0.02 mg/L

Selenium

2.50 mg/L

Zinc

5.5 – 10.5 s.u.

pH

0.7 mg/L

Cadmium

1.50 mg/L

Copper

0.7 mg/L

Lead

5.5 mg/L

Nickel

0.50 mg/L

Silver

200 mg/L

Fats Oil & Grease

150 degrees

Fahrenheit

 

Industrial Facilities that manufacture or process materials regulated under 40 CFR Subchapter N Part 405 to 471 are considered Categorical Industrial Users (CIU) and are subject to the Pretreatment Program requirements including categorical limits, individual permitting and monitoring. In addition, industrial and commercial facilities that discharge in excess of 25,000 gallons of process water a day are subject to the provisions of the Pretreatment Program requirements and may require an Industrial Wastewater Discharge permit from SAWS.

Industrial Wastewater Applications can be sent to the attention of the Industrial Compliance Supervisor at:

San Antonio Water System
P.O. Box 2449
San Antonio, TX 78298-2449

Questions concerning the SAWS Pretreatment Program or if you need contact information for the Supervisor or Permit Writers click here (pdf).

Facilities discharging industrial wastes from their operation which exhibit none of the characteristics of wastes prohibited by Chapter 34 of the City Code, other than levels of BOD or TSS having a concentration in excess of normal domestic sewage (concentrations in excess of 250 mg/l), shall pretreat the industrial waste to meet the concentrations of normal domestic sewage. The person(s) or owners responsible for the wastes pays an industrial waste surcharge, in addition to the regular water and sewer charges, in accordance with the cost factors and formula outlined in Chapter 34-226.3 for levels in excess of 250 mg/L.

SAWS as the Control Authority charges fees to recover cost associated with the Industrial Waste Program. These fees are listed in 34-484 of the City code and include permit and sampling fees. Special service fees are also listed under Schedule E.