Zoning board continues Pembroke quarry expansion hearing pending Water Works hydrology review

The Pembroke Zoning Board voted to continue the public hearing on Silver Hill Development Corporation’s request to expand Pembroke Sand & Gravel at 774 Silver Hill Drive, asking the applicant to coordinate a review of the submitted hydrogeologic report by Pembroke Water Works.

Chair (speaker 3) recommended, “have them meet with the Pembroke Water Works, have the Pembroke Water Works hire their own hydrologist at their expense, continue this meeting until that report comes back to us,” and the board voted in favor to continue the hearing to the next meeting.

Bridget Elsmore of Hoyle Tanner, who spoke for the applicant, described the operation’s history and the proposed increase in permitted excavation limits. She told the board the quarry has operated for decades and that the request would expand excavation limits by approximately 15.5 acres; the property is described in the record as 774 Silver Hill Drive (Map 559, Lot 12) in the C-1 Commercial/Light Industrial District, partially within the Aquifer Conservation Overlay District.

During public comment, resident Sean Collins and others sought clarification on the site plan, asking, “How close is the 15 acres gonna get to the property line?” The applicant and staff confirmed a 50-foot setback from property lines and explained proposed 2:1 slopes and erosion-control measures that would direct graded material toward the rock face. Commenters also asked whether blasting will occur; the applicant confirmed blasting is part of operations and said grading practices are intended to contain material within the site footprint.

A central factor prompting the continuance was a discrepancy between the applicant’s hydrogeologic report (prepared by Terracon Consultants) and a local conservation standard: board members read a planner’s note indicating excavation should remain a minimum of 8 feet above the seasonal high water table in the Aquifer Conservation District, while the submitted report references a 5-foot clearance in part of the proposed area. The town planner and Pembroke Water Works asked for the utility’s hydrologist to review the Terracon report and comment to the board before further action.

The chair and applicant agreed the Water Works’ review could be limited to reviewing the existing report rather than commissioning a full new study; the applicant said it would coordinate with Pembroke Water Works. The board’s motion to continue was made and seconded and passed on an aye vote.

The board indicated planning-board review and more detailed excavation standards (truck travel, road impacts, erosion control) will also apply as part of the permitting process; those steps are separate from the zoning board’s special-exception review and will use the same hydrogeologic information once the Water Works provides comments.

The hearing will resume once Pembroke Water Works’ hydrologist has reviewed the Terracon report and the applicant has coordinated with the utility; the board recorded the continuance and closed that item from tonight’s agenda pending receipt of the review.