South City Partners will build a wastewater detention vault beneath its redevelopment of the three-acre property in Avondale Estates, at the corner of Sams Crossing and U.S. 278.

Charles Welch, a development manager with South City, said his firm made the decision based on advice from a third-party engineer. Welch said the move is proactive since South City hasn’t yet heard from DeKalb County about any potential problems with a sewer tie in.

Last month the AJC reported that DeKalb identified 11 proposed development sites with potential sewer capacity limitations, and 60 other projects are still being evaluated.

Margaret Tanner, the county’s deputy director of the office of engineering and construction management services, told the AJC there are several ways the county and developers could collaborate in solving sewer issues, including “cost sharing.”

But Welch said this week that South City alone is paying for the vault, whose cost is still undetermined. He added that building the vault, beneath Hillyer Street on the development’s east side, won’t delay construction.

He expects to break ground by the end of the year. The Avondale project will include 196 apartments, 8,000 square feet of retail/restaurant space and one acre of open space, with construction expected to last 18 months.