Southeastern Public Service Authority members on Wednesday reviewed information showing how long the Suffolk landfill could last if additional cells are built.

The presentation was purely for informational purposes, Executive Director Rowland Taylor said. He said the eight member cities and counties should have the information as they deliberate what trash disposal in the area will look like after 2018, the contractual date for SPSA to cease operations.

“This information indicates you have considerable already-approved capacity,” Taylor told the board members.

The agency currently is dumping waste in Cell VI, which will last through about 2026 at current rates, according to the chart. Cell VII, which is already approved but not built, could last through 2055.

Rates have fallen sharply since 2008 due to several factors — most notably a sluggish economy, stronger recycling rates and the fact that municipal waste has been burned at a Portsmouth waste-to-energy facility since 2010. From 2008 to 2011, the tons dumped at the landfill decreased by 90 percent.

But from 2011 to 2012, the tonnages more than doubled, because the authority began dumping ash from the Portsmouth facility at the landfill. Its other main source of waste is from construction and demolition.

Taylor’s plan, which he described later as “very theoretical,” showed room for six more cells after Cell VII. But many of them are on property currently designated as wetlands.

Some board members were concerned about the possibility of building a landfill where wetlands once were.

“We have to be careful how we approach this,” said Eric Martin of Chesapeake, suggesting the authority “have dialogue early” with the U.S. Army Corps of Engineers and other regulatory bodies.

But other board members disagreed with that approach, suggesting it would be premature.

“We’re all going to be dead, probably, when this comes up,” said Marley A. Woodall Jr. of Chesapeake, drawing a laugh from the members.

If tonnage rates hover at 200,000 per year and the landfill is expanded to 13 cells, the facility could provide enough capacity until the year 2289, according to Taylor’s chart.

“There’s clearly a lot of work to be done by the communities,” Chairman Joseph Leafe of Norfolk said, referencing the need for continued dialogue on a post-2018 plan.

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