First Planning Board hearing is Thursday night
By Gene Robbins, Managing Editor
Gibraltar Rock Quarry wants to install nearly 10,000 solar panels on 14 acres of its mining operation to the north of Route 601 and off Long Hill Road.
Another 6 acres would be cleared of trees in order not to avoid shading of the panels.
The first hearing on the application will be at 7:30 tonight, Thursday, in the Hillsborough Municipal Building.
The company says it would supply 2.3 megawatts of electricity to its quarrying operation. The panels would stay there for their estimated life span of 20 years then be removed or upgraded.
All the electricity would go to make the quarry a “net zero” facility, said Joseph Nimphius, project manager for KDC Solar, based in Bedminster, which would lease the land and build the array.
Gibraltar would buy the power from KDC, he said. In seasons where the panels are producing more than the quarry operation could use, it would contribute energy to the PSE&G grid. In the shorter, darker days of winter, it would buy more electricity from the utility, he said.
The panels, which are permitted in the quarry district as an accessory use, would be located in Hillsborough, but the disturbed area would extend into Montgomery Township.
To give an idea of the size of the project, the Nelson’s Corner Shopping Center, which includes ShopRite, at Amwell Road and Route 206, is on 19.3 acres. The township elementary school across the street is on 12.9 acres.
An estimated 2,300 trees with a diameter of 6 inches or greater would be cleared for the 14 acres for the panels, roads and accessory buildings. Another 6 acres would be cut to prevent shading or branches and trees potentially falling on the panels.
Neighbors and environmentally minded people are raising questions about the proposal.
The township Environmental Commission has questioned the request for the economic hardship waiver, according to a letter on file. It would like to see the 5 acres of open area, where old machinery is located, used for a portion of the array, the letter says.
Mr. Nimphius said the plan would try to minimize the amount of grading and adhere to the natural contours in order to minimize runoff and potential soil erosion.
Removal of trees with accompanying fast runoff could keep water from seeping into the ground and ultimately affect well levels in the area.
The site is located on Sourland Mountain where “there is a continued concern for aquifer recharge,” reads a letter from the township Environmental Commission.
”The removal of 20 acres of trees will mean less recharge of the groundwater with potential impact to underlying aquifers,” the letter said.
Deborah Boyea, writing for the commission, also said the loss of trees will increase runoff maybe even “causing a possible dangerous situation and additional erosion.” The water would flow into tributaries to Back Brook.
”While the loss of trees for this project is not the issue, the function of what the 20 acres of trees does for the area is the concern,” she wrote.
Peg Van Patton, a former Hillsborough Planning Board member, is circulating a letter to residents of Dutchtown and Long Hills roads, warning of such concerns as runoff, soil erosion, loss of habitat, buffering and aquifer recharge.
”Here they will bulldoze to remove the existing soils to clear the area for the panels. Their plan calls for service roads, utility poles, an 8-foot-high chain link fence, concrete pads and a detention basin, which will empty stormwater runoff into that their experts refer to as ‘ditch’ the headwaters of Back Brook,” reads her handout.
Estimates from sample areas led to an estimate that 2,298 trees greater than 6 inches of caliper, 4 feet above grade, would be removed. The applicant’s forester determined that 1,291 healthy trees would be removed, resulting in the need for 3,774 replacement trees.
At $325 per tree, the cost of replacement trees, if not planted on site, would be more than $1.2 million. The township ordinance has provisions for an economic waiver that would limit the mitigation cost to 1.5 percent of site improvements, which Gibraltar has estimated at $7.2 million. That would make the mitigation cost $108,128 enough to plant 333 trees in places like parks and public space, as determined by the township parks department.
The Somerset-Union Soil Conservation District has asked for a sediment barrier on the downhill slope.
The county Planning Board says the plan calls for water to be detained in a basin, then released thorough one 24-inch pipe. Concerned that would change the runoff as it flows onto surrounding county-owned land, it asks for “an alternative treatment” that will “more closely mimic” existing sheet flow.
It also asks for more buffering and soil stabilization instead of granting the waiver from tree mitigation requirements.