The pump station on Holden Road in Youngsville spilled 5,025 gallons into the creek, which is a tributary of the Neuse River Basin.
The spill started shortly after 7:30 Tuesday night, lasting until just before midnight.
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Franklin County Public Utilities was dispatched to the site. Sewer hauling companies have been working to pump out and repair the station.
The Franklin County Public Utilities Department, according to its website, serves around 6,200 customers in Franklin County.