Over a period of six months, Transco attempted three horizontal directional drillings that were unsuccessful.
MONTGOMERY -- The New Jersey Department of Environmental Protection is scheduled to host a public hearing Tuesday over a requested permit change for an extension of the Transco pipeline near Princeton and Montgomery.
Transco has been unable to drill horizontally through fractured bedrock where they want to add a section called the Skillman Loop to Transco's existing Leidy Line.
Now they want to use a process called "cut and cover" where they cut a trench through the land and stream bed, lay the pipeline along the bottom of the trench and cover it up.
"Over a period of six months in 2015, Transco attempted three separate trenchless installations utilizing the horizontal directional drill method but was not successful due to the challenging geology in this area," Transco officials said in a statement Monday.
Transco officials say that the newly requested a cut-and-cover technique is "far above and beyond industry standards in a direct effort to minimize impacts."
While less environmentally friendly than horizontal drilling, this permit request comes with some more environmentally conscious concessions than does other cut-and-cover projects, the company says.
For the cut-and-cover method to be implemented, Transco will need to cut away an additional five feet of space along the path which workers and machinery already travel. The added room will allow for the necessary larger machinery.
A Transco spokesman said that additional five feet in width will cause minimal environmental impact as it will only bring the distance across the path to 30 feet -- less than half the industry standard of 75 feet for standard cut-and-cover jobs.
Part of the 'cut-and-cover' approach would require Transco to clear an additional 5 feet of space. (Transco photo) The New Jersey Sierra Club said that isn't good enough.
"This is a bad project in a bad place, and this permit will just be making it worse," Jeff Tittle, Director of the New Jersey Sierra Club, said in a statement.
"What Transco is proposing will cause even more environmental damage and devastation to this environmentally sensitive area," Tittle said.
"Their new proposal is even worse than before because they want to use a cut and cover approach to build the pipeline which will cause more siltation, erosion, and even could cause a mudslide during heavy rain," Tittle said.
Tittle worries that the construction associated with trenching the waterways will create temporary flood hazards for downstream residents.
He also says that burying the line in a trench will allow for additional thermal pollution to impact fish habitats and water quality. Horizontal drilling would at least allow for less temperature intrusion as the pipe would be further below the stream bed, he says.
Transco spokesman Chris Stockton disputed some of the Sierra Club's concerns, saying that the wetlands in area are already impacted by the current path clearing and that the two small streams to be crossed usually don't have any water in them.
Tittle says that Transco's inability to access the geography of the route for the Skillman Loop shows that the company doesn't do its homework.
Transco pointed out that they already have one pipeline -- laid using the cut and cover method -- running adjacent to the new line, and that the problems with horizontal drilling were unforeseeable.
The public hearing will take place Tuesday at 7 p.m. at the Upper Middle School auditorium at 375 Burnt Hill Rd., in the Skillman section of Montgomery.
Greg Wright may be reached at gwright@njadvancemedia.com. Follow him on Twitter @GregTheWright. Find NJ.com on Facebook.