30 Tex. Admin. Code § 332.7
Municipal sewage sludge composting facilities considered to be registered facilities in § 332.3 of this title (relating to Applicability) may be located at waste water treatment facilities that have received a water quality permit under the Texas Water Code, Chapter 26. The owner shall prepare and submit a modification to amend the water quality permit in accordance with the provisions of Chapter 305 of this title (relating to Consolidated Permits). The applicant shall comply with the provisions of § 332.4 of this title (relating to General Requirements) and § 332.31 of this title (relating to Definition of and Requirements for Registered Facilities) except where those provisions conflict with the provisions of the water quality permit. If the wastewater treatment facility has received a water quality permit under the Texas Water Code, Chapter 26, which authorizes compost operations, the compost operation shall be conducted in accordance with the facility permit.
30 Tex. Admin. Code § 332.7