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San Antonio, Texas

Stormwater Management


West Investments, LLC


KFW Engineers


 D&M Owens Inc.


January 2020

Technical Description:

  • 1,750' of 24" Aluminium Steel Type 2 
  • Stormwater Management Storm Filter®

Pic-n-Pac is a Texas chain of convenience stores established in 1964.  This latest store serves the needs of the growing area of North San Antonio, Texas. The constraints for this commercial site did not allow for a traditional above ground treatment and storage, so engineers turned to an solution.

The site is within the environmentally sensitive Edwards Aquifer Recharge Zone. The recharge zone is a 1,250 square mile area where highly faulted and fractured Edwards limestone outcrops at the land surface, allowing large quantities of water to flow into the Aquifer. To protect the Aquifer, the Texas Commission on Environmental Quality (TCEQ) requires treatment systems to have a an 80% TSS removal efficiency rating. 

Stormwater is first conveyed to an upstream equalization/detention systems made from 1,750’ of 24” diameter corrugated metal pipe (CMP). The captured stormwater is then directed to a Peak Diversion Stormwater Management StormFilter. The StormFilter contains 17 cartridges filled with ZPG media™,  a proprietary blend of zeolite, perlite, and granular activated carbon to improve the performance of perlite and target organics, soluble metals, and other pollutants. This is a common design principle used to provide detention as part of a stormwater quality system to hold back the necessary stormwater quality volume, while still allowing constant treatment by the downstream treatment unit.  

Contech provided TCEQ approved calculations and design details as part of the engineer’s stormwater pollution abatement plan. The combination of the CMP detention system and the StormFilter systems provided the most cost-effective treatment system to meet the stringent TCEQ requirements.

Technical Description:

  • 1,750' of 24" Aluminium Steel Type 2 
  • Stormwater Management Storm Filter®

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