An estimated 90,677 gallons of raw sewage spilled into the marsh on Tybee Island Sunday when a force main broke near 10th Street and Jones Avenue.
The spill, about two blocks from the Back River, is classified as major by the state Environmental Protection Division.
Tybee public works crews patched the pipe, but only after the sewage flowed for about six hours. Crews pumped sewage out of a nearby culvert and spread lime in the area to neutralize the spill and cut down on odor.
The timing of the break increased the spill’s volume, said City Manager Diane Schleicher.
“It’s the middle of our busiest season,” she said.
Regularly scheduled beach water tests at five locations on Tuesday came back clean for bacteria levels, according to David Lyle of the state Environmental Protection Division. The island benefitted from the natural flow of water dispersing the spill.
“There have been a lot of tide changes since then,” Lyle said.
Tybee crews patched the pipe Sunday and the city will look at replacing a larger section of pipe, up to 2,800 feet or more, possibly as part of a larger upcoming project to replace water lines and resurface Jones Street, Schleicher said.
Because the spill was greater than 10,000 gallons, state regulators require monitoring of the site daily for the first week and then a increasingly greater intervals over the next year.
That monitoring began as required, Tybee officials reported.