The Williams Transco company has revised its plans for installing a natural gas pipeline on the Princeton Ridge. Instead of digging open trenches in the environmentally sensitive wetlands, the company would use tunneling to avoid running into the area’s boulders and bedrock.

The changes came after extensive input from local residents, many of whom spoke at a public hearing before the New Jersey Department of Environmental Protection (NJDEP) last month. Others submitted comments in writing.

Williams submitted revised electronic plans to the NJDEP last week and will be providing hard copies to Princeton this week for review by officials and residents. The company’s Leidy Southeast Expansion project affects a 1.3-mile section of the Princeton Ridge.

“We’ve been working with the NJDEP for some time to reduce impacts to the Princeton Ridge,” said Transco spokesman Christopher Stockton. “We have agreed to six bores in the ridge area that would go under streams and wetlands, instead of a trench. The bores would be about five feet deep and 100 feet long.”

Local residents who are part of the Princeton Ridge Coalition have been monitoring Transco’s plans for the $650 million project, which would add a 42-inch diameter pipeline to an existing one. “While we haven’t yet seen the details, the decision to use boring in some areas is certainly a step in the right direction,” said Barbara Blumenthal, a member of the coalition, in a statement. “We have been telling Transco for the past two years that these were exceptional quality wetlands and that they needed to find an alternative, as required by regulations.”

In a related matter, the United States Court of Appeals for the District of Columbia Circuit issued an administrative stay on March 11 that temporarily prevents the cutting down of trees for the project. The tree clearing had been planned to start last week, but Transco will now have to wait until the environmental issues are ironed out.

Transco originally agreed to turn off the gas in the existing pipeline during heavy construction work, but more recently indicated it would go back to the Federal Energy Regulatory Commission (FERC) to request leaving the gas intact if the DEP did not act quickly to approve permits for the project.

“While avoiding these impacts on wetlands is critical, it is also imperative that NJDEP require Williams to turn off the gas in the existing pipeline during heavy construction work, as previously agreed,” said Coalition member Rakesh Joshi in a statement.

Princeton Council passed a resolution last month asking the NJDEP to insist that the pipeline be shut down during the construction.

A neighborhood meeting with Transco representatives and the project’s contractor, Henkels and McCoy, will be held Tuesday, March 24 at 7 p.m. in Witherspoon Hall. For more information, call the town’s engineering department at (609) 921-7077.