The eight member communities of the regional trash authority should make a decision in the next three years whether they want to stick together past 2018, a consultant said Wednesday.

SCS Engineers was hired to complete a study on the feasibility and desire of the eight communities to continue to cooperate past 2018, which is the contractual end date of the Southeastern Public Service Authority.

Bob Gardner of SCS said that generally, the communities to the west were more interested in breaking off and contracting with Waste Management to take their trash to its Waverly landfill, while the eastern communities mostly want to continue cooperating.

He did not clarify whether the western communities include Suffolk.

“We think that future cooperation of the member communities obviously has some value,” Gardner said.

He presented a summary of the report at the SPSA board meeting Wednesday. A full report is due by the end of the week, he said.

But future cooperation among the communities depends on a seemingly infinite number of variables — which communities will participate, how much they will pay, where trash will be disposed, how the management will be composed, and a host of other decisions.

Gardner also recommended that the Suffolk landfill be kept under government control, rather than being sold to a private entity.

“That regional landfill, publicly owned, is a huge asset,” he said. It still has about 30 years of capacity if additional cells are constructed, he said.

Projected tipping fees — the cost localities pay to dispose of household waste — would be about $80 per ton in 2019 and $110 per ton in 2027. The fee currently stands at $145.

However, Suffolk currently pays nothing to dispose of its trash, because it hosts the regional landfill — a so-called “sweetheart deal” that has raised the ire of some other members in the past. Gardner recommended serious talks about some type of payment from Suffolk in the future if SPSA goes forward.

“You’ll have to work through that,” he said.

SPSA is on track to pay off its remaining debt by 2018, so that is not expected to stand in the way.

“The SPSA debt is going to be retired, and we all know that’s a big deal,” Gardner said.

He will be making presentations to all eight local governments in the next two months, he said.

“Most of these decisions have to be made by the local governments before we can make any decisions about who’s in, who’s out,” said Chairman Joseph Leafe, who represents Norfolk on the board.

Gardner recommended making a decision by 2014.

The eight member communities of SPSA are Suffolk, Franklin, Southampton County, Isle of Wight County, Portsmouth, Chesapeake, Norfolk and Virginia Beach.