The Georgia Environmental Protection Division is investigating what it terms a "major" sewage spill at a retention pond used by the city of Portal.

State EPD officials performing a routine inspection Tuesday found an overflowing "stand pipe" behind the retention pond off U.S. Highway 80 West between Chipper's Lane and Larry Smith Road, said Bruce Foisy, district supervisor for EPD's Brunswick office.

It is unusual to find an overflow pipe at such ponds, he said. Usually, the retention ponds are kept from overflowing by pumping.

Portal Mayor Larry Motes said Thursday that the water in the pond, which comes from the city's wastewater treatment facility nearby, is distributed into a spray field. He said the water in the pond is treated; however, Foisy said the water is only partially treated and could pose a danger of contamination.

The pond overflowed because of recent heavy rainfall, Motes said. The pipe was "capped off" and the pond was pumped to relieve the overflow, he said.

Foisy said the EPD investigation is in its early stages and could take up to 30 days. Both the EPD and Portal city officials took water samples. The water eventually flows into Little Lotts Creek, which feeds into local water bodies including Lake Collins and Oglesby's Pond.

Motes said the city has used the pond for wastewater for about five years. He said the overflow has not affected Portal city residents.

"We fully expect this was a major spill," Foisy said, estimating the spill as exceeding 10,000 gallons.

EPD officials are "looking into" reasons the pond was allowed to overflow. The city of Portal could face fines and punitive measures, depending upon the investigation's findings.

A major question is why there is an overflow pipe there in the first place, Foisy said. Motes said he is unsure of reasons why the pipe and pond were constructed in that fashion.

The overflow problem was corrected Wednesday, he said. Foisy said the EPD investigation will continue.

Holli Deal Saxon may be reached at (912) 489-9414.