NTMWD and City of Plano Respond to Sanitary Sewer Overflow

North Texas Municipal Water District, City of Plano Respond to Sanitary Sewer Overflow

March 20, 2024

North Texas Municipal Water District Statement

The North Texas Municipal Water District (NTMWD) remains committed to protecting public health and the environment. We work closely with our communities to ensure safe, reliable operations of our regional wastewater conveyance systems, including preventing sanitary sewer overflows. However, even with preventative maintenance, these events may occasionally occur due to unforeseen mechanical issues, clogs in the wastewater system, or excessive rainfall.

The recent mechanical failure that led to the overflow in Plano was unfortunate, and we’re working around the clock to remedy the situation with the City of Plano and the appropriate regulatory agencies.

To ensure the safety and reliability of our systems, we implemented a revamped and expanded maintenance program for our wastewater conveyance system in 2017. Around this time, NTMWD also renewed our Sanitary Sewer Overflow Initiative (SSOI) agreement with the Texas Commission on Environmental Quality (TCEQ). Our SSOI established a proactive approach to reducing sanitary sewer overflows, and as part of that agreement, NTMWD committed to inspecting all our gravity wastewater pipelines within a ten-year period.

We completed the inspection of approximately 80 percent of the gravity pipelines over the first seven years of the program, and the results have indicated that a vast majority of the pipelines are in good to excellent condition. Pipelines of concern have been scheduled for rehabilitation, and that work is ongoing.

The NTMWD wastewater conveyance team operates 24 lift stations and over 240 miles of large-diameter pipelines throughout our service area. Lift stations, which help move wastewater to our wastewater treatment plants, are critical components of our wastewater system. Each lift station is checked by our staff every day, and all our lift stations are monitored 24/7 through a sophisticated control system. Comprehensive lift station condition assessments are completed every five years to identify long-term rehabilitation needs.

The Lower White Rock Creek Lift Station was constructed in 1976 and expanded in 1987. The lift station underwent a significant upgrade and renewal completed in 2020, which included all new electrical systems, pumps, and valves.

As part of our long-term maintenance program, we’ll continue to partner closely with our communities to invest in maintaining our regional water, wastewater, and solid waste systems to meet the needs of our growing region.

 

City of Plano Statement

The City of Plano is taking a myriad of steps to reduce the number of Sanitary Sewer Overflows. Since 2019, the numbers of sewage spills from manholes are trending down. We believe the decrease is due to the proactive steps the City has taken to replace and reline aging sewer pipes and improve lift stations. We also conduct routine inspections of our facilities and lines.

It’s important to note the wide array of causes of the overflows. Foreign objects that don’t belong in the sewage lines often play a role including flushable wipes, rags and grease. While this wasn’t the cause of the latest spill, it’s important that people know we can all play a role in reducing the causes.

The City of Plano participates in the Texas Commission on Environmental Quality (TCEQ) voluntary Sanitary Sewer Overflow Initiative. This helps identify the sources of our SSOs and how we proactively address them. Since joining the program, the City is making great progress on the 2025 proactive maintenance goals that reduce Sanitary Sewer Overflows in the system.:

  • Goal 1: To date we have completed inspections on 65% of our sewer mains.
  • Goal 2: To date we have completed cleaning of 88% of our sewer mains.
  • Goal 3: To date we have completed inspections on 94% of our manholes.

Based on these initiatives and programs, we have steadily reduced the number of SSOs. Ultimately, our goal is no overflows. However, with a system of our size, like most cities in the region, are going to have these incidents happen from time to time. We vow to respond to each and every one in a timely, responsible and effective manner to ensure the environmental impact is minimal.

Additional programs we have in place through our proactive efforts include:

  • Annual inspections of our sewer aerial crossings
  • Re-inspecting aerial crossings after storm events to identify damage from debris.
  • Proactive cleaning of “trouble spot” sewer mains on a 2-month, 3-month or 6-month schedule to prevent SSOs due to grease, wipes, or other items collecting in the sewer lines.
  • Daily lift station inspections that include checking pumps, motors, seals, valves, sump pumps and flood alarms; fence lines and building are also checked for security purposes. More in-depth inspections of structural, electrical and mechanical systems are completed annually.
  • Real-time flow monitoring throughout the system to evaluate infiltration/inflow (I/I) and key monitoring of previous SSO locations to respond before an SSO occurs.
  • Proactive sewer system rehabilitation for manholes and sewer mains.
  • Completed the Inflow and Infiltration Study of the Lower White Rock Creek and North Dallas Trunk Basins in January 2022. Two Sanitary Sewer Evaluation Studies (SSES) have been completed since and included inspections and testing of 739 manholes and 213,380 linear feet of pipe.
  • Our Community Investment Program (CIP) for 2023-2024 includes more than $19.5 million in projects to rehab or repair sewer infrastructure, clean and maintain sewer mains, lift station improvements, permanent flow monitoring, and projects to address development or capacity issues.
  • Implementation of a grease trap inspection program in 2018 that completes regular inspections based on a tier system approach. From 2022 – 23, over 621 grease trap and 189 grit trap inspections were performed during the current reporting period.
  • Education and outreach to residents and businesses are ongoing about proper disposal of fats, oils, grease (FOG) and disposable wipes.

All of the initiatives listed above were introduced with the goal of significantly reducing SSOs in the system and minimizing flows from SSOs when they happen.  The City of Plano has been and will continue to be committed to minimizing the occurrence of SSOs in the system through both proactive methods and swift responses with timely notifications when incidents occur.

 

Media Contacts

North Texas Municipal Water District 
Alex Johnson, Director of Communications
O: 469-626-4308  |  ajohnson@ntmwd.com

City of Plano
Steve Stoler, Director of Media Relations
O: 972-941-7321; C: 972-345-2393  |  stevest@plano.gov