TCEQ approves amended TPDES permit for Corex Utilities after contested hearing

The Texas Commission on Environmental Quality on Aug. 6 voted to adopt the administrative law judge's proposed order and issue an amended Texas Pollutant Discharge Elimination System permit to Corex Utilities, resolving a contested proceeding that centered on nutrient limits, dissolved-oxygen modeling and emerging contaminants.

The commission's action implemented three corrections recommended by the executive director and added a conclusion of law stating that federal or state law does not currently regulate contaminants of emerging concern (CECs) in TPDES permits; commissioners moved to issue amended permit WQ0013977001 in the form submitted by the executive director and to adopt the executive director's response to comments.

The matter reached the commission after contested-case testimony and briefing. Attorney for the applicant, Mr. Tuckfield, argued the discharge at issue is to an unnamed tributary with a minimal aquatic-life use for the first mile and said the draft permit complies with the Colorado watershed protection rule and includes a total phosphorus limit. "When it does reach the Colorado River, we have the Colorado watershed protection rule, which this permit complies with," Tuckfield told the commission.

Environmental Stewardship's counsel, Eric Ullman, told commissioners the discharge begins inside the McKinney Refs Nature Area and that the application contemplates expanding flow by roughly a factor of 10 to serve residential areas. Ullman said long-term monitoring and trend data compiled by LCRA indicate declining water quality in the reach and urged the commission to deny the application or impose stricter phosphorus limits. "We're saying when you look at that and you ask will this cause or contribute to a problem? The answer is yes," Ullman said.

The executive director's representative, Cole Mallon of the Environmental Law Division, recommended the commission adopt the ALJ's order with the executive director's exceptions and issue the permit, telling the commission the ALJ found the applicant met its burden on the referred issues; OPIC's counsel, Pranjal Mehta, said OPIC agreed with the ALJ except on the water-quality issue (issue A) and recommended either denying the application or revising the draft permit to include a more protective phosphorus limit.

Commission discussion cited the ED's technical testimony and the ALJ's handling of dissolved-oxygen modeling and nutrient screening. Commissioners agreed the draft permit requires compliance with odor-management requirements in chapter 309 and that the Colorado River watershed phosphorus limit in the draft was appropriate; they also directed that a conclusion of law be added addressing CECs. The motion to adopt the ALJ proposed order, include the ED corrections, add the CECs conclusion of law, and issue the permit passed after an oral vote of "aye." The record shows the commission adopted the proposed order and issued amended TPDES permit number WQ0013977001 to Corex Utilities, Texas Incorporated.

The ALJ had granted summary disposition in favor of the applicant on several threshold issues, and the remaining technical disputes focused on baseline conditions used in antidegradation analyses, the appropriate approach to dissolved-oxygen modeling in a small stream reach, nutrient impacts and the potential presence of PFAS and other contaminants of emerging concern. The commission noted it lacked authority under state or federal law to regulate CECs through TPDES permits in this matter and memorialized that view as a conclusion of law.

The commission also agreed to divide the transcript costs as recommended by the ALJ (75% to Corex, 25% to Environmental Stewardship) as part of the adopted order.

The commission's written order and the draft permit as adopted are part of the official record; the permit number cited in the hearing and adopted action is WQ0013977001.