By Gene Robbins, Managing Editor
In 2012, Gibraltar Rock applied for permission to cut down about 20 acres of trees in order to install solar panels to generate electricity for the 550-acre quarry operation on the Sourland Mountain ridgeline on East Mountain Road (Route 601), on the Montgomery-Hillsborough border.
The company withdrew the application in face of opposition to the loss of an estimated 2,800 trees, as well as potential stormwater drainage problems.
Gibraltar is back with a new plan — a larger one, but one that doesn’t cut down substantial trees. The proposal is scheduled to be heard by the Hillsborough Planning Board on Nov. 19.
In a Sept. 22 letter to Delaware and Raritan Canal Commission, engineer Robert Moscello of Gladstone Design says applicant KDC Solar, in conjunction with the property owner Gibraltar, has “re-evaluated the location” and now proposes to relocate an approximately 3-megawatt array to top of the existing tailings pile of byproduct crushed rock.
In the last application, Gibraltar said it didn’t think the tailings pile, a rounded, grassy, 100-foot-high, 1,000 feet in diameter area at the top of the ridgeline, was technically unsuited and unstable to support a solar array.
With no tree removal, the amount of disturbance is less than one acre and the increase in impervious surface less than one-quarter of an acre — therefore requiring no stormwater management, according to the engineer.
In 2012, the proposal suggested cutting down trees for the array installation, and another 6 acres of surrounding trees in order to avoid shading and having pieces of 100-foot-high trees fall on the panels.
Mr. Moscello’s letter says the increase in system size “is a result of increase in electrical usage by the owner.” The withdrawn application of three years ago called for about 10,000 three-by-six-foot panels to generate about 2.3 megawatts.
The 11.2 acres of the solar array would be surrounded by an 8-foot high fence. Solar panels will be designed with textured glass to reduce reflectivity, and put at such an angle to minimize glare.
Solar panels would be supported by galvanized steel posts driven into ground about 3 to 6 feet deep. Engineers said Gibraltar Rock said that no disturbance of the stockpiled materials has occurred since the pile was capped at least five years ago. Most of settling has occurred.
However, engineers recommended the solar panel field and construction equipment be kept at least 200 feet away from the top edges of the steep stockpile, just in case there might be potential slope failures.
