AUBURN — A lack of fresh runoff may make Auburn’s Outlet Beach a poor spot for the Twin Cities’ only public swimming hole, according to a water quality study released Thursday.

The study found levels of fecal bacteria that were higher than Environmental Protection Agency recreational standards in one-quarter to one-third of the tests performed since April 2005.

City councilors are scheduled to review and discuss the report at their workshop at 5:30 p.m. Monday in Auburn Hall.

The report was written by New Hampshire’s Comprehensive Environmental Inc. for the Lake Auburn Watershed Protection Commission and the city, based on water quality tests done between April 2005 and last summer.

It was commissioned after the beach was closed to swimming twice last summer due to coliform bacteria in the water. The bacteria can cause minor skin and eye infections, gastrointestinal disorders and respiratory illness.

“Understanding the physical constraints of that area, I don’t think it’s built to support swimming for large numbers of people while still remaining healthy,” said Mary Jane Dillingham, water quality manager for the Auburn Water District and the Lewiston Water Department.

Auburn has no public swimming pools.

Outlet Beach is on the Lake Auburn outlet on the east side of Route 4, so swimming has been allowed. It is open from Memorial Day weekend through Labor Day weekend.

Swimming is not allowed in Lake Auburn because it is Auburn and Lewiston’s water supply.

The study looked at levels of two types of bacteria, enterococcus and E. coli, in water samples taken out the small pond. Both are common bacteria in human and animal digestive systems.

The study found the enterococci bacteria exceeded EPA standards for freshwater recreation areas in 38 out of 120 samples and E. coli bacteria levels that surpassed standards in 29 out of 120 samples.

A lack of fresh water may be to blame, according to the study. Because of the topography of the area, water runs from Lake Auburn to the outlet and into Bobbin Mill Brook, a tributary to the Androscoggin River.

Lake Auburn feeds the outlet through a single 25-foot-wide spillway under Route 4. Fresh water follows an eight-foot-deep stream through the outlet and runs out through a spillway into Bobbin Mill Brook under Fair Street.

The outlet is also fed from stormwater running off Route 4 and the neighborhood to the south and east of the site. That runoff can be contaminated with oil, metals and bacteria, according to the study.

The outlet’s water can become stagnant, especially during summer months when fresh water stops flowing in from Lake Auburn and out through the Bobbin Mill Brook outlet. Geese, ducks and gulls that have nested at the outlet beach may also be responsible for contamination.

Beach-side erosion and overuse as a recreational area may be responsible as well, according to the study.

“Ideally, a good swimming beach would be located in a larger body of water,” Dillingham said. “That’s why we don’t want people swimming in Lake Auburn; it’s what happens in heavily populated swimming beaches.”

Councilors have discussed making $65,000 worth of improvements to the area, including a water slide, a wharf, new playground equipment and bathrooms. They put those ideas on hold in November when the study was commissioned.

City Councilor Leroy Walker said councilors need to consider whether the outlet is worth preserving as a swimming beach.

“We really need to look at all the options,” he said. “Maybe we can make the dam automatic to let water out during hot weather. And if we can’t swim in the lake, it wont’ be the end of the world but I’d hate to see that happen.”

The beach costs the city $10,140 each summer for maintenance, water quality testing and utilities.

“We could have paddle boats, canoes and all that,” Walker said. “We could have volleyball and a big picnic area. There’s a great opportunity there, but I’m not ready to give up on swimming yet.”

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