After months of deliberation, the state approved Tweed-New Haven airport’s plans Tuesday to make infrastructure improvements to its runway that eventually will enable the airport to expand its operations.

Tweed and New Haven officials welcomed the Department of Environmental Protection’s ruling, which will allow the airport to build runway safety zones, bringing it in line with Federal Aviation Authority regulations. They said the decision paves the way for the airport’s expansion, which will ultimately boost the local economy. But East Haven officials said they are upset over the DEP’s decision because constructing the safety zones will destroy local wetlands and because an expansion of the airport would bring unwelcome noise and traffic to East Haven.

DEP spokesman Dennis Schain said his department took into account the impact on the airport’s future development when making its decision. While the airport’s expansion would destroy over 15 acres of titled wetlands, Schain said, Tweed will be required to restore other wetland areas on the airport’s land.

“We believe that work that the airport considers important could be accomplished in a manner that minimizes the impact on the environment,” he said.

The construction of the runway safety area marks the first step of a four-stage master plan to offer flight services out of Tweed to destinations within a radius of 2,000 miles from the Elm City by 2019. While the runway safety area will not increase the actual length of the runway from its existing 5,600 feet, the third stage of the master plan, if implemented, would extend the runway by 1,000 feet.

New Haven Mayor John DeStefano Jr. said the development of a regional airport in New Haven is crucial to the city’s welfare and growth. Had the airport not received permission to build the runway safety zones, DeStefano said, the airport would have had to reduce the length of its runway to comply with FAA regulations, decreasing the airport’s ability to offer services to the region.

“Transportation infrastructure is key to moving people and goods, it is key to economic growth, and it is key to quality of life,” he said. “The safety zone areas allow us to use the full amount of the pavement we currently have.”

But East Haven Mayor Joseph Maturo, who has been a strong critic of the airport’s master plan, said he is very disappointed with the DEP’s decision because the wetlands that will be destroyed are precious to the local environment. He said he is afraid an extension of the runway would result in an expanded airport and further inconvenience for the local community.

“The airport authority would not give us in writing that they would not pave those runway safety areas,” he said. “They told us verbally they would not pave it, but they would not give us anything in writing.”

But Airport Authority Chairman Lawrence DeNardis said he does not think a written agreement was necessary because there are currently no immediate plans to extend the runway, and that even if there were, it would involve another extensive application to the DEP. The airport authority may seek to extend the runway at some point in the future, he said, but not in the next few years.

Delta Airlines abandoned services to Tweed in January 2006, leaving U.S. Airways as the airport’s only carrier until PanAm Clipper Connection started flights to Baltimore Washington International Airport and four small airports in the northeast in March.