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Septic Systems

Septic systems have long been a common way to process and dispose of waste products in areas that are not served by a sanitary sewer collection system. With a septic system, the wastewater is treated on-site, rather than collected and sent to a centralized wastewater treatment facility.

The Geronimo and Alligator Creeks WPP identified failing septic systems as a potential source of pollution for both bacteria and nitrate nitrogen. There are an estimated 2,303 septic systems in the Geronimo and Alligator Creeks watershed. Failure estimates for the watershed ranged from 5 to 15%, depending on location and age of the system. The cost to repair a system can vary substantially depending upon the type of system and cause(s) of failure.

Common causes of system failure include improper location of the system, improper design, faulty construction, improper operation, system overload, and poor or no maintenance of the system. If you suspect your system is failing, contact your local service provider. To report a suspected septic system violation in Guadalupe County, contact the Guadalupe County Environmental Health Department at (830) 303-4188 extension 250. To report a suspected septic system violation in Comal County, contact the Comal County Engineer’s office, Environmental Health Department at (830) 608-2090.

GBRA has developed online training modules that illustrate the components of both conventional and aerobic systems. The modules allow users to manipulate the systems to function properly or cause a system malfunction. To view the modules go to:


For more information and free publications about septic systems, visit http://ossf.tamu.edu/.

Fact Sheets

Understanding and Maintaining Your Septic System
Responding to Power Outages and Floods
Operation and Maintenance

Past Presentations and Handouts

Introduction to Onsite Wastewater Treatment (7MB download)

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