Residents of the four Wake County towns affected by the pending construction of a new wastewater treatment facility could soon have their first chance to weigh in on an environmental impact report to be filed by the U.S. Army Corps of Engineers.

Once built, the wastewater plant would serve residents in Cary, Apex, Holly Springs and Morrisville.

A draft of the federal agency’s environmental impact statement could be the subject of a public forum that might take place early next year, said Leila Goodwin, Cary water resources manager, during a Cary Town Council work session Tuesday. A final draft of the report could be completed by next summer.

Staff from Apex, Holly Springs and Morrisville -- the three towns joining Cary in a partnership to build the facility -- were on hand at the work session. The meeting was held in a conference room at Town Hall.

Meanwhile, planning continues for the Western Wake Regional Water Reclamation Facility. At an estimated cost of about $300 million, the project would become Cary’s third wastewater treatment plant. Construction of the facility could begin as early as January 2010, according to a project timeline.

The project is 85 percent designed and remains in the site selection process. Goodwin said last week that a site near the southwestern Wake community of New Hill remains the preferred site for the plant. But she said the western Wake partners were also still evaluating three other potential sites along New Hill Holleman and Friendship roads and Old U.S. 1.

The project has proved controversial in recent years for residents of New Hill and Chatham County. Among their concerns: Lights, noise and an unpleasant odor could make living in their community less desirable. Other environmental concerns, along with fears that the addition of services could bring undesired growth, have also been atop protesters’ list of worries.

Goodwin said at least some of those fears could be relieved if the western Wake partners successfully appeal to the state to allow wastewater to be discharged into Harris Lake. The move would be an alternative to prior plans to discharge the wastewater into the Cape Fear River downstream from Buckhorn Dam.

Goodwin told the Town Council there could be several benefits to the proposed change, which initially garnered negative response from the state in 2002. She said it would mean construction of a shorter pipeline, which could reduce environmental impacts in Wake County and eliminate the risk for residents of Chatham County.

Steve Brown, director of public utilities, said later that it appeared unlikely that changing the discharge site would affect the western Wake partners’ choice of a preferred site for the facility. He said site evaluations at Harris Lake had showed “that the preferred site [in New Hill] is still the best site.”

Also, Goodwin said the shift would eliminate the need for an effluent pump station on the upstream end of the pipeline. Goodwin told Cary Mayor Harold Weinbrecht and the Town Council that cutting the pump station out of the plan would reduce energy costs and offset some of the costs associated with project delays that have pushed back the facility’s opening from 2011 to 2013.

The two-year delay increased the price tag for construction of the wastewater treatment facility by about $30 million, Goodwin said.