City responds to wastewater discharge after contractor damages force main

The City of Lewisville is notifying the public of an unauthorized wastewater discharge that occurred after a contractor working on a City project struck a 36-inch wastewater force main in the 700 block of E. Valley Ridge Boulevard, on Thursday, Nov. 5.

The incident was reported about 11:30 a.m. Wastewater was initially contained within the excavation while City crews and contractors worked to control the release and begin repairs.

At approximately 4:30 p.m., wastewater breached the excavation area and discharged into Prairie Creek. The discharge continued for approximately five minutes before the contractor constructed an improvised berm within Prairie Creek, stopping additional wastewater from moving downstream toward the Elm Fork of the Trinity River.

Wastewater contained within the bermed section of Prairie Creek is being pumped out and conveyed directly to the wastewater treatment plant for treatment.

The force main is a pressurized pipe within the City's wastewater collection system and carries domestic wastewater. The City has confirmed that the total wastewater discharge exceeded 100,000 gallons; however, the final estimated volume, including the amount that reached Prairie Creek, is still being calculated. The City's drinking water system was not affected.

Repairs to the damaged force main are underway. City staff are monitoring conditions in Prairie Creek and downstream of the affected area. Additional cleanup and remediation measures will be implemented based on field conditions and monitoring results.

Public health precautions

As required by the Texas Commission on Environmental Quality, the following precautions are recommended for areas potentially affected by the wastewater discharge:

• The public should avoid contact with waste material, soil or water in the area potentially affected by the discharge. If contact occurs, individuals should bathe and wash clothes thoroughly as soon as possible.
• Persons using private drinking-water supply wells located within one-half mile of the discharge site or within the potentially affected area should use only water that has been distilled or boiled at a rolling boil for at least one minute for all personal uses, including drinking, cooking, bathing and tooth brushing.
• Individuals with private water wells should have their well water tested and disinfected, if necessary, before discontinuing distillation or boiling.
• Persons who purchase water from a public water supply may contact their water supplier to determine whether the water is safe for personal use.

The City has notified the Texas Commission on Environmental Quality and will submit required follow-up information, including the final estimated discharge volume, affected area, monitoring results, corrective actions and other applicable documentation.

The City will continue monitoring conditions and will provide additional information as it becomes available.