Supreme Court of Texas Decision Affirming Contested Dripping Springs TPDES Permit

by Nathan E. Vassar

Nearly a decade after the application for a TPDES permit was filed, the City of Dripping Springs’ discharge permit received the approval of the Supreme Court of Texas in Spring 2025. The case has been followed by industry groups, municipal/other utility permittees, and various stakeholders over multiple years as it worked its way through the appellate process. As detailed below, in a unanimous decision, the high court determined that the TPDES permit satisfied the antidegradation standard as applied by TCEQ over the arguments of protestants, Save Our Springs Alliance, that water quality would be degraded by greater than a de minimis amount.

Following oral argument in Fall 2024, many anticipated this result based on the questions presented by the Justices. The Court’s focus in both the oral argument as well as in the opinion was on whether impacts to a particular water quality parameter would amount to degradation of water quality as a whole under the TCEQ’s antidegradation rules. Several critical takeaways are apparent from the decision, including analysis of antidegradation policy in Texas, as well as deference to the permitting decisions of TCEQ once a permit is issued.

Save Our Springs argued that because of potential impacts to dissolved oxygen due to the loadings of nutrients into the receiving waters under the permit, there would be impermissible degradation. By contrast, counsel for Dripping Springs and TCEQ had contended that the agency was perfectly within the confines of antidegradation review because, even though there may be individualized impact when looking at a particular parameter, such impact would not equate to wrongful harm to water quality in the receiving stream in the aggregate. The Court agreed, and declined to set a precedent where a certain threshold percentage impact would be considered degradation for a specific water quality parameter.

The Court also considered TCEQ’s process in following its implementation procedures in reviewing the application. Although not precisely identical to the now-overruled federal “Chevron deference” framework, in Texas, if an agency takes action on a permit such as the City of Dripping Springs’, the reviewing court is supposed to ask whether there is “substantial evidence” supporting the agency’s decision – or basically some reasonable basis for the agency to reach that conclusion. As such, permittees can continue to rely upon a process where courts look to an agency’s consistency with its own rules and procedures, as was the case here.

The earlier rounds of court review raised concerns for the wastewater permitting community, particularly as the district court initially deemed that the permit issuance effectively would turn the Clean Water Act upside down, focusing on the increased nutrient loadings over and above existing conditions. The El Paso Court of Appeals upheld the permit issuance, but in a split 2-1 decision.

Overall, permittees and their teams should continue the work that they typically perform in ensuring a sound technical basis for requested effluent sets and that TCEQ staff has the necessary information to defend agency permitting decisions. Other litigation tied to nutrients will be followed closely in the months and years to come, including TCEQ’s recent permitting decision regarding a new restrictive nutrient limit in the City of Liberty Hill’s permit, but the high court’s decision for the City of Dripping Springs is widely seen as a victory for wastewater utilities across the state.

Nathan Vassar is a Principal in the Firm’s Water, Compliance and Enforcement, Litigation, and Appellate Practice Groups. If you have any questions or would like additional information related to this article or other matters, please contact Nathan at 512.322.5867 or nvassar@lglawfirm.com.