Tetra Tech has ensured Eagle Pass, Texas, a community along the Rio Grande, has had clean, safe drinking water for more than 15 years. Tetra Tech has provided design and construction oversight services and funding application assistance for more than 20 water and wastewater improvement projects to upgrade and expand aging infrastructure to keep pace with the area’s growing population.

Under its first engineering services contract, Tetra Tech evaluated the city’s water and wastewater facilities for potential expansion of capacity, distribution, and collection and design of a potable water facility. Tetra Tech evaluated the existing potable water treatment plant and recommended numerous upgrades, including building a 15-million-gallons-per-day (mdg) ultrafiltration membrane treatment facility. Our team designed pump stations, transmission pipelines, more than eight miles of distribution pipelines to reach underserved areas, and three one-million-gallon elevated storage tanks. Tetra Tech also prepared funding applications and worked with the city and various agencies to secure funding from the State of Texas Water Development Board and the U.S. Environmental Protection Agency (EPA), representing more than 60 percent of all project funding.

The project, which Tetra Tech completed in 2006, was the first membrane filtration plant to treat water from the Rio Grande. After pilot testing various ultrafiltration membrane systems, Tetra Tech selected the one with lowest lifecycle costs encompassing capital expenditures, membrane replacement, chemical feed, backwash, and energy costs. EPA recognized the project with the Performance and Innovation in the State Revolving Fund Creating Environmental Success (PISCES) Award, which recognizes projects that are innovative and effective through the State Revolving Fund programs.

Tetra Tech completed the next major component of improvements, designing and constructing a 1.5-mgd wastewater treatment plant, in September 2010. Our team extended wastewater collection infrastructure to underserved areas, designed sewer interceptors to deliver wastewater to both the existing and new plant, and designed the city’s first reclaimed water system to treat wastewater for local irrigation. The new wastewater treatment plant maximized effluent recycling while reducing demand from the Rio Grande.

Tetra Tech also oversaw the development of a 20-year Water and Wastewater Master Plan, including an analysis and comprehensive summary of the planned capital improvements to the water and wastewater system. Tetra Tech completed water and wastewater demand projections, capacity analysis, and project identification and development.

In 2016 the Eagle Pass Water Works System (EPWWS) selected Tetra Tech to oversee the design and construction of the ultrafiltration treatment plant’s expansion and membrane replacement, which will expand the existing facility from 15 mgd to 19 mgd. The membranes had reached the end of their useful lifespan and were in need of a replacement. Tetra Tech conducted a thorough evaluation of the existing treatment plant to identify the process and facility needs to meet future capacity requirements, while preserving and enhancing the reliability of the treatment plant. Tetra Tech also helped obtain regulatory approval for the proposed replacement ultrafiltration membranes, which were not yet approved for use in Texas, avoiding the delay and costs of challenge studies. The team prepared funding applications and worked with EPWWS and the Texas Water Development Board to secure low-interest loans for the treatment plant expansion. Final design of the expanded facility was completed in the summer of 2017.

Tetra Tech has established a standard water and wastewater infrastructure, which all future plans must follow, and provided a model for communities along the Rio Grande. Our team continues to provide operations and maintenance services for the community’s water systems.


U.S. EPA recognized the original facility with the Performance and Innovation in the State Revolving Fund Creating Environmental Success (PISCES) Award