A sewer line break in McKinney unleashed what city officials estimate was about 100,000 gallons of household wastewater into Rowlett Creek.
McKinney Wastewater Superintendent Harlyn Farrell said he believes it is the largest break the city has ever reported.
"It's a 30-inch line, so it carries quite a bit of water," he said.
Farrell blamed erosion along the riverbank for the issue with the pipe.
The mess has been contained and the final piece of the new line will be installed by the end of the week, but the city is warning residents to avoid contact with any soil, water or waste material in the area.
Debbie Gandy said the smell was "horrible."
We couldn't go in the backyard at all," she said.
Gandy, who lives alongside the creek and its adjacent trail, said she was concerned about possible contamination coming downstream.
"We'll have to do some research before we go walking out there and bring the dogs and kids around," she said.
But Farrell there is no evidence of a fish kill or other problems.
He said he believes the wastewater was diluted by the normal creek flow.
"There's no toxic chemicals in this wastewater, no industries on this wastewater," he said. "The water is safe."
The Texas Commission on Environmental Quality been notified of the incident.