Texas environmental officials are investigating a sewage spill on March 14 that flowed into White Rock Creek, a small tributary that feeds into White Rock Lake in Dallas.
A pump and motor failure caused by a broken valve at the Lower White Rock Lift Station in Plano, run by the North Texas Municipal Water District (NTMWD), caused wastewater to overflow through three manholes near the 5500 block of West Plano Parkway. The overflowing sewage then drained into nearby White Rock Creek.
An estimated 500 gallons of sewage per minute flowed into the creek for more than 38 hours, according to a City of Plano news release. By the time the overflow was halted on March 16, more than 1.5 million gallons of sewage — equivalent in volume to three Olympic-size pools — had made its way into the creek.
Plano officials were quick to assure the public that city drinking water was not affected and remains safe to use.
Within a few days, the wastewater spill had made its way southward several miles to White Rock Creek in Dallas, prompting Dallas Park and Recreation officials to temporarily suspend water recreational activities at the lake, beginning March 19. Park officials advised residents not to fish or enter the water due to elevated bacterial levels. Boaters and rowing and yacht clubs were warned to avoid activities in the water until further notice.
This isn’t the first time an overflow of sewage from Plano has found its way into White Rock Creek.
In July 2018, a damaged pipe caused over 1 million gallons of sewage to flow into White Rock Creek. In October 2018, an overflow from a Plano manhole resulted in 159,900 gallons of wastewater contaminating the creek. In November 2011, a fallen tree damaged a sewage line, leading to 100,000 gallons of wastewater overflow.
Dallas City Council Member Paula Blackmon (District 9) responded to the leak in a Facebook post, stating, “This is unacceptable! City of Plano and North Texas Municipal Water District need to invest in the maintenance and replacement of sanitary sewer systems that ultimately impact the North Texas Region and our downstream cities.”
“Many of our sewer lines are aging,” said Steven Stoler, director of media relations for the city of Plano, in an interview with The Dallas Express. “That means there are cracks. When we have heavy rains, water can leak into the sewer lines. It has nowhere to go, so it overflows from a manhole.”
He also stated that grease, debris, flushable wipes in the sewer lines, and concrete from nearby construction entering the sewers are common causes of overflows.
The city of Plano is a member of the Texas Commission on Environmental Quality’s Sanitary Sewer Overflow Initiative and is actively working to address overflow issues.
“We continue to maintain a rigorous maintenance and repair schedule along with aggressive efforts to replace and reline aging sewer pipes,” said the TCEQ in a 2023 summary report provided by Stoler. A contractor was hired to clean and inspect sewer mains and the associated manholes, cleaning roughly 90% of sewer mains since September 2020.
Exactly how much sewage made its way from Plano to Dallas is unknown. To dilute the wastewater, Plano added dechlorination tablets and flushed the creek with water, TCEQ spokesperson Victoria Cann told The Dallas Morning News.
The water lift station in Plano has begun operating again with temporary equipment in place. The NTMWD said it could take two weeks to fully repair the valves damaged during the recent mechanical failure.
The TCEQ is heading the investigation into the wastewater overflow.
