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Lower Leon Creek: Fish Tissue Sampling Project

A completed project to assess high PCB concentrations in fish tissue in Lower Leon Creek.

photo of Lower Leon Creek below the site of Kelly Air Force Base
Lower Leon Creek below the site of
Kelly Air Force Base

County: Bexar
Parameters: Polychlorinated biphenyls
Basin: San Antonio River
Segment: 1906

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Project Background and Goals

Lower Leon Creek, Segment 1906, flows from a point 100 meters upstream of State Highway 16 northwest of San Antonio in Bexar County to its confluence with the Medina River. The watershed is primarily a highly urbanized residential area, and drains approximately 190 square miles. The watershed includes Lackland Air Force Base and the former site of Kelly Air Force Base.

In 2002, the Texas Department of State Health Services (now the Department of State Health Services) issued an advisory restricting the consumption of all species of fish from the creek because concentrations of PCBs in the tissues of fish posed an unacceptable risk to consumers.

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The TCEQ contracted with the Department of State Health Services (DSHS) to collect and analyze additional fish at five stations along Lower Leon Creek. Their analysis resulted in a new fish consumption advisory (ADV-42), which expanded the geographic extent of the original advisory (ADV-26).

Local interest in the fish consumption impairment also spurred a survey and characterization of PCBs in sediments. This survey was a collaborative effort of U.S. Geological Survey (USGS), San Antonio River Authority (SARA), San Antonio Metropolitan Health District (CoSA) Public Center for Environmental Health (PCEH). Monitoring at the former Kelly Air Force Base has also yielded PCB data.

The final report from USGS characterizing PCB levels in sediments from Lower Leon Creek and other streams in the San Antonio River basin was published in 2011.

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Public Participation

TCEQ staff worked with the Steering Committee of the San Antonio River AuthorityExit the TCEQ to keep the public informed of the status of fish tissue sampling activities. The Steering Committee is established under the Texas Clean Rivers Program.

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For More Information

For additional information regarding this assessment, please e-mail us at, and mention the Lower Leon Creek fish tissue sampling project in the subject line. Or call us at 512-239-6682.

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communities working together taking care of our rivers, lakes, and bays