Over the past seven months, voters in four Island towns have approved funding for a major expansion of the Martha’s Vineyard Refuse District transfer station. The $2.5 million project is expected to triple the Edgartown station’s vehicle capacity and to allow for future expansion.

Chilmark easily approved the spending at a special town meeting in October, and Aquinnah soon followed with unanimous support at a special town meeting in November. At town meetings in April, a large majority of West Tisbury voters approved the spending, and Edgartown offered nearly unanimous support without discussion.

Each member town will contribute to the 20-year bond payment based on an assessment of how often it uses the station. Edgartown will pay 69.5 per cent, with West Tisbury paying 15.5 per cent, Chilmark paying 12 per cent and Aquinnah paying three per cent.

The project aims to reduce traffic congestion in part by creating a new road and separate drop-off facility for residential traffic. The Chilmark selectmen have asked that the district also include a second drive-on garbage scale at a cost of about $144,000. The West Tisbury selectmen have asked that the new station include an area where people can pick up reusable construction materials.

The expansion as planned will not exceed the station’s buildable footprint, and a 200-foot buffer zone will remain intact. District manager Don Hatch said Wednesday that the expansion will use all of the district’s available space. “This is to free up an area for future plans and development with the district five, 10, 15 years down the road,” he said.

A previous 15-year bond will be paid off by the towns this year, Mr. Hatch said, so the annual assessment for each town will not increase as a result of the project.

Mr. Hatch said that a new contract with the Southeastern Massachusetts Resource Recovery Facility (SEMASS) in Rochester, where most of the district’s waste and construction material ends up, has reduced operating costs for the district, allowing user fees to stay level. But those savings will not affect the cost of the project.

A public meeting June 15 at the Edgartown transfer station will invite comment from abutters, along with representatives from the nearby Dukes County offices and Martha’s Vineyard Airport. Other next steps for the district include appearing before Edgartown permitting boards and the Martha’s Vineyard Commission. Mr. Hatch believed the project may qualify as a development of regional impact (DRI), requiring MVC approval. He plans to meet with the commission this spring.

In addition, the Department of Environmental Protection is requiring a modification to the district’s environmental permit to allow for construction.

Current plans call for about 158,000 square feet of new pavement, at a cost of $1.1 million. With the costs of asphalt and concrete subject to change, the goal is to complete construction next year. The district plans to update its estimated costs for concrete and asphalt prior to the June 15 meeting.

Working with the engineering firm Environmental Partners of Hyannis, the district plans to develop a final design, which Mr. Hatch said will likely resemble the firm’s other projects on the Cape. In a best-case scenario, he said, construction would begin mid-winter, with final paving and concrete work beginning in the spring. He hoped the project would be completed by June 2016.