The city of Senoia may soon embark on an ambitious upgrade of its sewer treatment facility that could provide treatment capacity to the huge McIntosh Village project in unincorporated Coweta County west of and adjacent to Peachtree City.

The plan was unveiled during a Friday morning workshop meeting and would feature a 2-million-gallon treatment plant near the Fayette border that would dump the effluent into Line Creek.

The plant would be located on a 15-acre site mostly owned by Riverwood Studios on Chestlehurst Road and could cost up to $16 million in construction and land acquisition costs.

Senoia city engineer Ben Turnipseed explained the city’s current permit allows 490,000 gallons a day to be treated, and currently the city is using 137,700 gallons a day.

But in December, Senoia officials met with Coweta County and Reese Developers, which is developing McIntosh Village, about upgrading the capacity of its plant. Since McIntosh Village is in the unincorporated county, the county would be the customer for the city’s expanded capacity.

Turnipseed said Reese has pledged $6 million for 1 million gallons of treatment capacity, with the payment spread over the next six years.

A 2-million-gallon a day plant would have the capacity to serve 20,000 residential customers, along with industrial and commercial needs, he added.

While the actual cost of the plant would be just over $7 million, Mayor Robert Belisle warned that land acquisition costs and building an interceptor line to service McIntosh would increase the cost dramatically.

“I would think we would need at least $7.5 million from Reese if they wanted to spread the payments out,” Belisle said.

In meetings with Coweta County and Reese, the three sides agreed to have a preliminary deal in place by the end of January. Belisle instructed the city’s staff to get back in touch with the developer and Coweta County and provide the two sides with the city’s perspective on the issue.

“I think this is a doable deal,” said city attorney Drew Whalen.

If the deal is completed, Turnipseed estimated construction could start next February with the plant operating in August 2009.

Senoia last year sought to hook up to Peachtree City's sewer system, but was turned down by the City Council.