Howard County officials issued a precautionary health alert Friday after nearly 1.3 million gallons of sewage overflowed in a Columbia townhouse community this week.

The county’s Department of Public Works was first notified of a potential sewage overflow behind 9405 Watchlight Court at noon Wednesday, the Health Department said in a news release Friday.

The spill, the result of a broken main sewage overflow, is estimated to have lasted more than 30 hours, from noon Wednesday to 6:15 p.m. Thursday, health officials said.

A bypass pump was installed at approximately 6:15 p.m. Thursday.

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County residents need to “avoid contact with the water from the point of discharge, continuing downstream including Lake Elkhorn” and to keep family pets away from affected water as well.

The Bureau of Utilities is on site.

In August, roughly 160,000 gallons of sewage overflowed at the Little Patuxent Water Reclamation Plant. Only a small amount entered a storm drain, with the bulk overflowing onto the plant’s ground surface, county officials said at the time.

The Maryland Department of the Environment has been notified of Wednesday’s sewage overflow. Any questions can be directed to the Bureau of Utilities at 410-313-4900.