EVERETT — The Snohomish County Council on Thursday unanimously endorsed extending by up to five years a $20 million annual contract to send garbage to an Eastern Washington landfill.

Now, it’s up to County Executive Aaron Reardon’s staff to finalize an agreement with Allied Waste Services.

The council defused tensions with Reardon on the trash issue by including an opt-out clause that would allow the county to terminate the contract early.

The motion passed 5-0 during a special meeting.

“I’m going to support the motion with the opt-out language because — first, of all — I don’t think it’s likely,” Councilman Dave Somers said. “But certainly, if the process is complete and it’s ready to go, that’s a reasonable compromise.”

Somers’ colleagues echoed his comments, with Councilman John Koster saying the proposal would give the county flexibility, whether the schedule moves faster or slower than expected.

Councilman Dave Gossett stressed the need to build in time to deliberate, involve the public and to reach an agreement.

The current contract with Allied Waste is scheduled to expire in May 2013. The council’s proposal calls for a four-year extension, with an optional extra year.

It’s up to Allied to decide whether to accept the extension. A company spokesman said Thursday the new language will be reviewed.

“Allied Waste is excited to continue our partnership with the people of Snohomish County to provide excellent services and dependable, good jobs for local families,” said Randy Bolerjack, who noted the agreement would give the county a $500,000 per-year discount over the existing rate.

Reardon had been urging a contract extension of no more than two years. The rhetoric got to a point where the executive’s office called the council’s support of a longer extension “fiscally irresponsible” and “legally questionable.”

Reardon has said the county could save more than $2 million per year by switching trash haulers, but hasn’t publicly explained how he reached that figure.

“We are pleased the council chose to support including an early termination clause in the contract,” Reardon’s office said in a statement distributed Thursday. “Failure to include an early termination clause would have been a deal-breaker for the executive.”

The long-haul garbage contract is for disposing 400,000 tons of waste the county produces annually. Allied does that by shipping trash by train from a north Everett rail yard to a landfill in Roosevelt, east of the Cascade Range. It’s separate from curbside pickup and recycling, though any rate changes could affect what people pay for garbage service.

The original agreement was signed in 1990.

Much of the debate between the executive and the council has revolved around how long the county likely will need to draw up a request to solicit bids from other companies that want to compete for the county’s trash business.

Acting more quickly to open the county’s waste-export contract to competing bids, Reardon reasoned, could save the county money through market competition.

Members of the council, meanwhile, feared that Reardon’s proposed timeline failed to account for public involvement or adequate study, and could have spelled trouble down the road.

Reardon’s staff agrees that preparing to reopen the contract will require years of work — just not as many as the council says. His staff put together a timeline suggesting it could be completed before mid-2015. The council’s review of the timeline suggested the work would take more than a year longer.

Under the council’s initial plan, the contract would have remained in place through 2015, the final year of Reardon’s term as county executive. Term limits prevent him from seeking the office a fourth time.

Allied Waste is part of Phoenix-based Republic Services, the second-largest company in the waste industry.

The industry’s biggest player, Houston-based Waste Management, has shown a strong interest in the county’s trash, and has sent representatives to keep close watch on county meetings, including the one on Thursday.

Tim Crosby, a district manager for Waste Management, said he would have preferred a shorter extension because his company could be ready for the work within 18 months.

“I would have liked to have seen it earlier,” Crosby said, “but I’ve been in government before and I know how government works.”

The incentive for the county to act now, he said, is the promise of lower rates that have come with the economic downturn. Trash haulers nationwide have been forced to cope with a drop in business and have extra space in their landfills, he said.

It’s a well-established economic trend that people tend to produce more garbage when the economy is robust, and less when it’s not.

“There is space available,” Crosby said. “It’s a good opportunity for the ratepayers to see some relief.”

Noah Haglund: 425-339-3465; nhaglund@heraldnet.com.