Downstream from Harlingen along the Arroyo Colodado lies the community of Arroyo Colorado Estates.

Residents there faced some of the worst flooding of Thursday’s severe thunderstorm.

Part of the water that flowed down the Arroyo Colorado on Friday was untreated wastewater.

According to the Harlingen Waterworks System, 633,500 gallons of "partially treated waste water" was discharged into the river due to a power outage.

Rio Grande City and the city of Alamo also reported unauthorized discharge of wastewater from their treatment facilities due to the storm.

Rio Grande City, the city of Alamo and Harlingen Waterworks Systems each released a statement saying that the discharge did not affect the drinking water supply in any way. 

“There's probably not a storm drain system or a wastewater system that can even handle this type of scenario,” Harlingen Waterworks System Director David Sanchez said. “So everybody is going to be having similar experiences with their wastewater plants, even their city drainage."

Sanchez said the flooding pushed flood water into the sewer system, adding more sewer water to treat.

“If we could have had power and maintained the power, we would have been good, “Sanchez said. “We would have been treating, then we would have not had to issue this. But the power failure just cut us off at the knees."

Harlingen Waterworks System is asking customers to voluntarily reduce their water usage 

The Texas Commission on Environmental Quality confirmed to Channel 5 News that they are investigating multiple wastewater discharges in connection with the recent storm. The state's environmental agency declined to say which utility companies are part of the investigation.

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