SANDISFIELD — The Tennessee Gas Pipeline Co. has been given the green light to start clearing trees and begin building its natural gas storage loop through Otis State Forest.

In a letter dated Tuesday, the Federal Energy Regulatory Commission said the company can start laying pipes for the company's 13 mile, $93 million Connecticut Expansion Project that will also run through parts of New York and Connecticut.

The letter said the company had filed the necessary information "to meet the pre-construction environmental conditions."

It's been a big controversy in Berkshire County, in part because the state-owned land is protected by Article 97 of the state Constitution, and because it borders an old growth forest and a pristine lake in a treasured state park. While the project will run along an existing pipeline run, that corridor has to be expanded to make room for the new project.

Tennessee Gas was planning to begin the work more than a year ago, but it ran into delays when the state Attorney General's Office sued because the project required that the state grant the easement.

Berkshire Superior Court Judge John A. Agostini ruled last May that eminent domain through the Natural Gas Act of 1938 trumped state law, and set the company's plans in motion.

"Article 97 of our state Constitution is meant to protect the right of our citizens to the quality of life that clean water and undeveloped open space can provide," said Paula Kohler, a Sandisfield resident. "It is a shame when that protection is made useless by federal law."

Local environmental groups, whose legal actions also delayed the project, are still hoping to hold the company's feet to the fire during clearing and construction.

"They have to work in accordance with all the permits issued for the project," said Kathryn Eiseman, director of the Massachusetts PipeLine Awareness Network.

"There are erosion control measures, protections for vernal pools, and wetland replication as part of the commonwealth's mitigation package."

"That's assuming that Kinder Morgan in fact follows the law," she added. Kinder Morgan is the parent company of Tennessee Gas Pipeline Co.

Kinder Morgan spokesman Richard Wheatley referred questions about the company's adherence to permit conditions to FERC, and would only say the project had been well vetted before it was approved.

"The project received a thorough and thoughtful review by state and federal agencies during the last two years," he said, adding that the company is "pleased" to have the go-ahead. He also said the project will help feed increasing demand for natural gas in the Northeast.

It was unclear when the company would begin construction work.

Yet there is another wrinkle still outstanding with FERC: The Narragansett Indian Tribal Historic Preservation Office filed a letter of opposition with the agency last week over the company's request to proceed with tree clearing, saying the matter of sacred Native American sites in the pipeline path had not been fully attended to.

State Rep. William "Smitty" Pignatelli, D-Lenox, said he isn't surprised by FERC's notice, but he said all the delays to the company's plans were important to local protections.

"It was well worth the fight, though I knew it was going to be an uphill battle," he said, adding his famous line about agency in this situation, "once again, we got FERC-ed."

But throughout the battle to save this forest, Pignatelli said he wanted to protect Sandisfield, population 800, from what will be an invasion of heavy equipment that will exert wear and tear on the town's already rough roads and other infrastructure.

Kinder Morgan and town attorneys had drafted an agreement that the company would give the town roughly $1 million to mitigate this, and reimburse $40,000 in attorney fees for this negotiation.

But the agreement — also made verbally — was never signed.

"I hope Kinder Morgan will be honorable and fulfill the agreement," Pignatelli said.

Reach staff writer Heather Bellow at 413-329-6871.