Tex. Water Code § 26.0282

In considering the issuance, amendment, or renewal of a permit to discharge waste, the commission may deny or alter the terms and conditions of the proposed permit, amendment, or renewal based on consideration of need, including the expected volume and quality of the influent and the availability of existing or proposed areawide or regional waste collection, treatment, and disposal systems not designated as such by commission order pursuant to provisions of this subchapter. This section is expressly directed to the control and treatment of conventional pollutants normally found in domestic wastewater.