Almost 4,000 gallons of untreated sewage spilled last month into a creek that feeds into Montgomery County’s Lake Frank, officials said.
The sewage backed up out of a manhole and into a creek that flows into Lake Frank in the Rock Creek basin, said a spokeswoman for the Washington Suburban Sanitary Commission. The 54-acre lake is in Derwood, east of Rockville.
WSSC spokeswoman Lyn Riggins said the sewage overflow began Jan. 18 around 1 p.m. and ended Jan. 19 around 2 a.m. A total 3,921 gallons flowed into the creek, she said.
Riggins said the WSSC found grease in the line. Liquid grease poured down drains can clog sewer pipes after it hardens, causing sewage to back up. The utility urges residents to pour grease into a can and throw it away after it cools and hardens. Restaurants are required to have systems to intercept grease and keep it out of the sewer.
Riggins said the WSSC, which provides water and sewer services to Montgomery and Prince George’s counties, plans to clean out the sewer line and inspect it with a camera. The WSSC has had trouble getting equipment to the site because it is in a remote area, she said.
Like many other sewer utilities, the WSSC is under a federal court decree to reduce the number of sewage overflows. Riggins said the utility did not put out a press release on the spill because the consent decree only requires it to do so when the sewage overflow exceeds 10,000 gallons.