Tex. Water Code § 49.230
The powers and duties conferred on the district are granted subject to the policy of the state to encourage the development and use of integrated area-wide wastewater collection, treatment, and disposal systems to serve the wastewater disposal needs of the citizens of the state whenever economically feasible and competitive to do so, it being an objective of the policy to avoid the economic burden to the people and the impact on the quality of the water in the state that result from the construction and operation of numerous small wastewater collection, treatment, and disposal facilities to serve an area when an integrated area-wide wastewater collection, treatment, and disposal system for the area can be reasonably provided.
Tex. Water Code § 49.230