University Star

Texas State students have created an interactive map detailing sewage spills over the recharge zone of the Edwards Aquifer in Bexar County, which could have future health and environmental implications.

A team of four students found the spills totaled more than 809,000 gallons since 2004. Yongmei Lu, associate professor in the Department of Geography, said her students created the map for a “service learning” project. The students had to apply skills learned in class to help a non-profit organization, in this case the Greater Edwards Aquifer Alliance. Lu said what started as a class project ended up raising questions about the environmental impact of urban development on and near the Edwards Aquifer.

Lu said Brady Nock, Mark Wilson, Rachael Weissman and Amy Woods were a part of the GeoTex Environmental Solutions student group that put together the interactive map. The map provides the latitude and longitude of the spills, when they occurred and how much sewage was discharged.

Annalisa Peace, executive director of the Greater Edwards Aquifer Alliance, said the sewage spills can be caused by many issues. The spills can result from breaks in water pipelines caused by rust, shifts in the earth or clogs from things people should flush down their drains, like grease. Sewage spills are particularly troublesome over the aquifer’s recharge zone because water is not filtered when it enters the aquifer from those locations.

“This is really a cause for concern because when you look at the amount of raw sewage spills in the San Antonio area, that’s all going into the aquifer,” Peace said.

Peace said with an increasing amount of development coming into the San Antonio area, more and more sewage pipelines are being installed.

Lu said in big cities with densely developed neighborhoods, like San Antonio, sewage pipelines are used. Residents of San Antonio get their drinking water from the Edwards Aquifer.

Diane Wassenich, program for the San Marcos River Foundation, said it is “not a good plan” to develop on the Edwards Aquifer recharge zone. She said the sewer lines break, spills happen and residents end up drinking the contaminated water.

“It’s never good to have raw sewage mixed with your drinking water,” Wassenich said.

Lu said many residents in San Marcos have septic tanks on their properties, so as a result, their wastewater never goes through sewage pipelines. There are subsequently far fewer sewage leaks in Hays County in comparison to Bexar County. San Marcos’ smaller population is a factor, she said.

Wassenich said there have still been sewage spills in town, even though the Edwards Aquifer recharge zone in San Marcos is not as highly developed as it is in Bexar County. The City of San Marcos has been steadily upgrading its sewage system, with improvements recently being made on the pipelines on Sessom Drive.  

Lu said it is especially important for the water in San Marcos to be uncontaminated. When contaminated water enters the aquifer, it will pollute the San Marcos River years later. The endangered species unique to the area, such as Texas Wild Rice, will disappear if sewage spills keep occurring.

“If we don’t take care of this now, future generations will suffer,” Lu said.