Almost 16,000 gallons of untreated sewage flowed into a creek in Rockville over the weekend, according to the Washington Suburban Sanitary Commission (WSSC).

The unnamed creek near 6120 Executive Blvd. is part of the Cabin John watershed basin in Montgomery County, utility officials said.

The overflow, which occurred at a rate of over 50 gallons per minute for about five hours Saturday afternoon, came from a manhole cover and was caused by rags and tree roots that had blocked a sewer main, the WSSC said.

The utility, which is under a federal court agreement to reduce sewage overflows, notified the Maryland Department of the Environment and the Montgomery County Health Department, officials said.

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