ACCOKEEK, Md. (AP) — The Washington Suburban Sanitary Commission says a mechanical failure triggered a nearly 323,000-gallon sanitary sewer overflow at the Piscataway Wastewater Treatment Plant.

WSSC says the partially treated wastewater was contained on the grounds of the plant in Accokeek on Monday morning. A gate that allows wastewater to flow from the ultraviolet disinfection channel malfunctioned, causing the overflow, but operators were able to open other channels when the malfunction was discovered.

The Maryland Department of the Environment and the Prince George’s County Health Department have been notified. WSSC crews spread lime on the affected area.

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