River Authority Wastewater Treatment Plant Expansion Update

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River Authority's Martinez IV Wastewater Treatment Plant

The San Antonio River Authority (River Authority) is a full-service wastewater utility provider serving a portion of northeast Bexar County since 1966. Over the years, we have grown to help provide utilities assistance to communities throughout Wilson, Karnes, and Goliad counties as well.

Read along as we share more info about our wastewater treatment plants (WWTP) and the most recent updates as we work on two plant expansions!

River Authority Wastewater Treatment Plants

Today, the River Authority operates and maintains five permitted and active WWTP. Fun fact, all but one River Authority WWTP is named after the creek the treated wastewater is discharged into. The plant names are Salitrillo, Upper Martinez, Martinez II, Martinez IV, and First Responders Academy. These plants, located in East Bexar County, utilize the latest technology to produce a high-quality effluent to preserve the ecosystems into which the effluent is returned. Effluent is wastewater treated or untreated that flows out of a treatment plant, sewer, or industry outfall. Combined, the River Authority WWTP plants have a capacity of over 13.59 million gallons per day (MGD)!

Salitrillo and Martinez IV Wastewater Treatment Plant Expansions

Salitrillo Wastewater Treatment Plant

Currently, two WWTPs are in the process of undergoing plant expansions. Plant expansions assist in servicing and updating our treatment systems, system administration, and operation and maintenance. Expansions are funded by connection fees, interest income on utilities funds, and uniform user rate charges.

The Salitrillo WWTP located in Converse, Texas, is the River Authority’s most senior plant opened in 1966. The plant is currently permitted at 5.83 million gallons per day, with an average daily flow of approximately 4.86 MGD. This plant will be expanded to 7.33 MGD to accommodate expected development in the area. This will be a progressive design build project and is anticipated to be completed by 2022. Presently, this project is being contracted and is estimated to cost $25 million.

The Martinez IV WWTP located in St. Hedwig, Texas, is the River Authority’s newest WWTP, opened in April 2019. Not only is it the newest, but the plant received a Silver Envision Rating from the Institute of Sustainable Infrastructure. The plant serves 2,200 customers and is permitted for 0.25 MGD. Due to the unexpected rapid development in the area, the WWTP is already near its capacity and needs an expansion. Currently, the design team is assessing the level of expansion needed and the cost.

Request a tour or presentation!

River Authority staff conduct a wastewater treatment plant tour.

As these projects progress, you can look forward to detailed updates in our Utilities newsletter, The Clarifier. You can also request a presentation by a River Authority staff member to learn more about our current projects and initiatives or you can also request a tour of one of our WWTP from our Utilities team. There is also a special tour of the Martinez II WWTP as part of the 2021 River Symposium!

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