Sister Grove Regional Water Resource Recovery Facility
To meet the growing needs in the northern part of our regional system, the Sister Grove Regional Water Resource Recovery Facility (RWRRF) is being constructed. Following a thorough evaluation to identify a suitable location for the facility in 2016 and 2017, NTMWD purchased 1,000 acres of land near the FM 2933 and County Road 336 intersection. In February of 2020, the Texas Water Development Board (TWDB) approved $459 million in low-interest state funding for the Sister Grove RWRRF. The TWDB Clean Water State Revolving Fund (CWSRF) Program financing is expected to save $212.8 million in interest costs on this project. In April of 2020, NTMWD received its discharge permit from the Texas Commission on Environmental Quality (TCEQ). Construction began in Fall 2020.
NTMWD provides wholesale wastewater treatment services to 1.6+ million people across 24 communities in the North Texas region. Some of the fastest-growing communities in the nation are located in the northern part of the NTMWD service area. To continue reliably serving these thriving communities, we must plan for the future.
Project Overview
- Located on 1,000 acres near the FM 2933 and CR 336 intersection
- $459 million low-interest funding from the TDWB; Expected to save $212.8 million in debt service for NTMWD and those we serve
- NTMWD received TCEQ permit in April 2020
- Currently permitted to 64 million gallons per day (MGD) annual average daily flow (AADF)
- Phase I construction/operations includes 16 MGD AADF and 64 MGD peak flows
- Phase II construction to expand to 32 MGD AADF and 128 MGD peak flows began in September 2025
- Includes advanced treatment and odor control technologies
- A discharge location was identified based on proximity and operational factors
Project Timeline
While construction on Phase 1 is not yet complete, we have begun the extensive start-up process, putting equipment into service in advance of normal operations. Start-up processes are a critical part of bringing a new treatment facility online and are not reflective of normal operations. During start-up, systems undergo extensive testing while construction continues.
As we go through the start-up process, we may experience some unexpected challenges, which could cause odors to escape the plant site. Our teams have identified some issues and are working diligently to minimize these odors and reduce their impact. If you experience odor concerns, please contact us at wastewater.info@ntmwd.com or by calling 469-626-4900. One of our dedicated team members will respond.
Crews continue working across the site, finishing out the facilities, testing equipment, finalizing electrical work, instrumentation, and road paving. As part of the start-up process, the plant began receiving wastewater flows in late August 2025 and discharged its first treated effluent into Stiff Creek in mid-September. The plant’s effluent meets or exceeds regulatory requirements.
Phase 1 of Sister Grove RWRRF is anticipated to be fully operational in Spring 2026. Download the fact sheet.
History
Following a thorough evaluation to identify a suitable location for the facility in 2016 and 2017, NTMWD purchased 1,000 acres of land near the FM 2933 and County Road 336 intersection. In February 2020, the Texas Water Development Board (TWDB) approved $459 million in low-interest state funding for the Sister Grove RWRRF. The TWDB Clean Water State Revolving Fund (CWSRF) Program financing is expected to save $212.8 million in interest costs on this project. In April 2020, NTMWD received its discharge permit from the Texas Commission on Environmental Quality (TCEQ). Construction began in Fall 2020.
NTMWD held two public meetings on this project, and District staff have spoken about it at McKinney and New Hope city council meetings. After listening to residents and meeting with city officials in McKinney, New Hope, and Princeton, NTMWD made some changes to the project. The peak flow basins were moved closer to the plant and further away from the property boundaries. Additionally, we are adjusted the screening planned for the south end of the property to better shield the view of the facility for homeowners in the area.
The NTMWD Board of Directors discussed and voted on various portions of the project over the years. NTMWD continues to provide public updates during all steps of this project, from construction through operations.
- What is a water resource recovery facility?
-
Water Resource Recovery Facilities provide continuous wastewater treatment to meet water quality limits stated in the TCEQ issued permit prior to discharging into a body of water. These facilities are a critical element in maintaining the health of our watersheds and the public. NTMWD is voluntarily implementing a watershed protection plan to further safeguard the Lavon Lake watershed with increasing urbanization in the area.
- Why do we need the new sister grove regional water resource recovery facility?
-
Currently, 700,000+ people are served in our northern service area by two existing facilities and projected growth will exceed the existing facilities serving Collin County in the very near future.
- How will the environment be protected and impacts mitigated?
-
Protecting water resources and preserving the natural environment is a high priority. Similar NTMWD facilities operate in this same manner and discharged water is typically of higher quality than naturally existing water in creeks and streams. As our team determined the location of the facility and its outfall location, a site was selected to minimize impacts on area streams and Lavon Lake. The Sister Grove RWRRF facility is being built to maintain the natural surroundings at the outfall location.
As the project continues, NTMWD will:
- Meet or exceed all local, state, and federal environmental protection requirements from design through operations
- Engage and inform area communities throughout facility planning, construction, and operation
- Treat recovered water resources to high quality in compliance with TCEQ requirements
- Include advanced treatment and odor control technologies
- How will NTMWD make sure nearby homes and businesses are not affected?
-
NTMWD is building the new Sister Grove RWRRF to serve one of the fastest-growing areas in the country. As part of our commitment to being a good neighbor to our northern service area, the plant is centrally located within the 1,000-acre site, with additional screening of visible structures and facilities with landscaping and berms. The plant is also designed to mitigate and minimize local impacts to odor, noise, or light from the facility.
Advanced treatment and odor control technologies will be implemented, and noise will be addressed through the use of sound enclosures or dedicated buildings around specific equipment and processes.
The facility’s lighting plan will incorporate modern LED technology, specifically warm-white lighting, downward-facing fixtures, and motion-activated noncritical lighting, all aimed at minimizing the impact of lighting on the surrounding areas.