More than 27,000 gallons of sewage spilled into a creek in DeKalb County because of a grease blockage in a manhole Monday, officials said.

The sewage spilled into North Fork Peachtree Creek off Dering Circle in Chamblee, according to a report from the DeKalb County Department of Watershed Management. Crews found the overflow in the creek’s tributary at about 2:45 p.m. Monday.

The spill was stopped nearly 12 hours later, after 2 a.m. the following day.

A grease blockage — and a possible structural malfunction — in a manhole caused the overflow, the report stated.

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Officials initially said 13,240 gallons of sewage spilled from the manhole. They later upgraded that figure to 27,760, meaning it was classified as a “major” spill by U.S. Environmental Protection Agency standards.

DeKalb County is in the process of upgrading its aging sewer system, years after entering into an agreement with the EPA and Georgia's Environmental Protection Division to reduce sanitation spills. Officials acknowledged earlier this year that the county will not meet its 2020 deadline to fix the system, and it could take an additional five years.

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