Liberty Hill

SOUTH SAN GABRIEL RIVER ALGAE POLLUTION

For years, the worst sewage pollution in Texas has been caused by the treated wastewater that the city of Liberty Hill, located west of Georgetown, has been discharging into the South San Gabriel River. The problem has beeen that Liberty Hill's wastewater contained more phosphorus than what’s naturally in the river. Phosphorus acts as a fertilizer that causes plants to grow, including algae. The result has been that the South San Gabriel, which meets the criteria for a pristine stream, has been blanketed with miles of excessive algae growth for more than a decade.

In 2024, TCEQ's commissioners took a historic step by renewing Liberty Hill’s discharge permit with the agency's lowest-ever limit on the amount of phosphorus that can remain in wastewater after treatment. The commissioners voted unanimously to re-issue the city's discharge permit with a total phosphorus limit of 20 micrograms per liter (mcg/L). The agency’s previous lowest limit for phosphorus in a discharge permit was 150 micrograms per liter (watch a replay of the commissioners' meeting).

THE LATEST: TCEQ has started a possible enforcement action for Liberty Hill's discharge permit since the city has yet to comply with its new phosphorus limit.

This montage of consecutive segments from a drone video shot by Ryan King in 2020 showed how excessive algae grew on the South San Gabriel for miles downstream from Liberty Hill's wastewater discharge outlet, located at the midpoint of the photo at far left.

The effort to improve Liberty Hill's permit took almost a decade and started with complaints submitted to TCEQ by Stephanie Ryder Morris, who lived directly across the South San Gabriel from the city's wastewater outlet. When Liberty Hill filed for renewal of its permit, Morris and her downstream neighbors asked that a contested case hearing be held. TCEQ's commissioners eventually ordered that an extremely rare second contested case hearing should be held in order to specifically determine what the phosphorus limit should be in Liberty Hill's permit in order to stop the growth of excessive algae on the South San Gabriel.

Save Texas Streams coordinated a fundraising campaign that enabled Morris and her legal team to retain Ryan King of Baylor Univeristy, a nationally recognized water quality expert, for the second hearing. King's testimony and evidence was key in convincing TCEQ's commssioners to renew Liberty Hill's permit with an unprecedentedly low phosphorus limit of 20 micrograms per liter. Other major funders who contributed to King's testimony included the Jacob and Terese Hershey Foundation, the Hill Country Alliance, and the Llano River Watershed Alliance. Save Texas Streams also presented Morris with our Pristine Streams Protector award in 2023 for her many years of volunteer advocacy on behalf of the South San Gabriel.