A divided Ascension Parish Council agreed Tuesday to open up negotiations with the sole bidder for a 30-year, $300 million proposal to bring regional sewage treatment to much of unincorporated Ascension’s east bank.

Coming at the tail end of one administration and near the start of another in January, the move marks the second time in five years the parish will try to close a deal on a public-private partnership with a team of companies to bear the upfront cost and risk associated with creating a regional system.

Some council members argued Tuesday the time is now to make the tough decisions after years of procrastination and false starts going back to the 1970s.

Others said they are uncomfortable with the cost for residences — an average of $67 per month and onetime hookup fees of $4,500. Still others said they are disappointed they had only one proposal to look at while other potential bidders had asked for more time to make an offer.

The vote was 5-3, with council members Teri Casso, Todd Lambert and Bryan Melancon voting no.

Councilman Randy Clouatre, as chairman, does not vote unless to break a tie. Councilmen Dempsey Lambert and Chris Loar were absent.

Several companies are on the team: GSA Consulting Engineers, Citibank, Provident Resources Group, Layne Heavy Civil, Haskell and Ascension Wastewater Treatment and its associated construction company.

The proposal was not made public until after the vote. Despite a public records request in mid-November, parish officials refused to release the engineering or financial details, such as user fees, to The Advocate, saying they were proprietary business information until after an internal engineering review panel made its recommendation.

On the same basis, parish officials kept the engineering review committee’s meeting Thursday closed to public.

Before the council voted Tuesday, Ken Dawson, parish chief administrative officer, said the proposal met the requirements of the parish’s request for proposals.

A parish attorney provided a CD with an electronic copy of the proposal to a reporter after the meeting ended.

Clouatre and outgoing Parish President Tommy Martinez said Tuesday the public will have input before the final vote is cast on the long-term deal. The proposal also would have to go before the state Public Service Commission.

Councilman Benny Johnson, chairman of a council committee that has been exploring sewer for years, said having only one bidder gave him “great pause” and said he wanted more time for more proposals but was comforted in that his committee will have input on the negotiations to shape the final plan.

“I’m glad to hear that, at the end of the day, there’s going to be more conversations as far as the particulars of the plan, because if it wasn’t, there would be no way in the world I would support this going to the administration,” he said.

Follow David J. Mitchell on Twitter, @NewsieDave.