Graham Glaser, who is the cheese buyer for River Valley Market in Northampton, recommends cheeses for holiday parties Saturday, Nov. 3, 2016, at the store. A round of parmigiano reggiano rests on the counter, left. He is holding a package of brillat savarin affine.

NORTHAMPTON — While the state-mandated minimum wage went up from $11 to $12 in the new year, workers at River Valley Co-op are seeing an even greater wage boost.

Starting on Monday, the lowest wage in the store rose to $15 an hour due to a new contract between the unionized workers and store management.

On Jan. 4, River Valley Co-op and United Food and Commercial Workers Local 1459, the union that represents store workers, signed the new three-year contract, according to a joint statement from the union and the grocery store.

“This is a big stride forward in strengthening economic well-being and security for the workers,” Jeff Jones, a vice president with UFCW Local 1459, said in the statement.

Ninety-six percent of workers approved the contract, the statement said.

“It feels really good to be ahead of the state on this,” said general manager Rochelle Prunty. She said that previously, the minimum wage at the store was $12.50 an hour.

The state minimum wage went up a dollar an hour in 2019, and will continue to incrementally rise to $15 an hour by 2023 under the so-called “grand bargain” bill signed into law in June. In Northampton, the living wage is $13.36 an hour for a single person without children, according to Living Wage Western Mass, a group that certifies employers as paying a living wage.

Negotiations for the recent agreement have been in the works since the summer of 2018, according to Prunty.

In the joint statement, union steward Olivia Vicioso compared creating the contract as “being part of a think tank.”

“Our only constraints,” she said, “were our imagination and of course feasibility, acceptability, and benefit to the purpose at hand: a safe, functional, and progressive work place that meets both staff and management needs.”

She added, “I’m so proud of our team for approaching this new contract with compassion, empathy, and open-mindedness and for ensuring that each team member had an equal voice at the table.”

Now, as the store eyes expanding to Easthampton for a second location, the agreement would also cover those potential workers.

River Valley Co-op has an option to buy a 3.17-acre property at the old Fedor Oldsmobile Pontiac car dealership on Route 10. The potential store, which would be a comparable size to the one in Northampton, would create about 100 jobs, a co-op press release said in August.

“This agreement goes through 2021,” Prunty said of the contract. “We are hoping very much to open in 2020. So this agreement would cover them as well.”

Greta Jochem can be reached at gjochem@gazettenet.com