Planning board approves major amendment to Route 9 gravel pit with strict monitoring, blasting and insurance conditions

The Keene Planning Board voted to approve a major amendment to an earth‑excavation permit and a hillside‑protection conditional‑use permit for an expanded gravel pit on Route 9 (PB-2024-20), adding a package of conditions addressing erosion control, groundwater monitoring, blasting monitoring, reclamation and insurance.

The applicant, Granite Engineering LLC, on behalf of owner G2 Holdings LLC, sought to expand an existing operation on two parcels that together total roughly 109 acres in the rural district and requested waivers from several Land Development Code provisions, including the 250‑foot surface‑water setback, prohibitions on toxic/acid‑forming materials and the five‑acre excavation maximum. Planning staff and outside consultants had previously reviewed the application and the board continued deliberations on conditions at the special meeting.

After the board’s initial motion to approve, members proposed and adopted several additional, specific conditions by amendment. Key conditions added in the final approval include:

- Precedence and security: submission of owner signatures, final plan sets (paper and digital), and sufficient security to cover sedimentation/erosion control, stormwater management and reclamation for each permit period prior to starting work.

- Ongoing monitoring and reporting: monthly third‑party inspections by a qualified, licensed professional for erosion control and stormwater; monthly groundwater and surface‑water level monitoring across permit periods with a 24‑hour reporting requirement for any adverse impacts; semiannual groundwater‑quality testing during operations and for two years after reclamation.

- Seasonal high water table confirmation: installation and monitoring of designated monitoring wells (referring to the location B R W‑09 and a monitoring well in permit period 1) to confirm revised grades will be at least six feet above the seasonal high water table prior to work in affected phases.

- Blasting controls and monitoring: compliance with New Hampshire Administrative Rule Saf‑C 1600 series vibration and air‑overpressure standards; a licensed independent third‑party blasting consultant acceptable to the city must install seismographs at selected structures and other sensitive receptors within a two‑mile radius (with focus on closest residences, wells and sensitive receptors), record vibration and overpressure for the first blast, and submit certified monitoring reports to the Community Development Department within 14 days of the blast. If monitoring shows exceedances, blasting must cease until corrective measures and additional third‑party monitoring are completed at the applicant’s expense.

- Insurance: the applicant must maintain a commercial general liability policy with an endorsement for blasting and excavation exposures (covering structure/well damage, groundwater/surface water contamination, fly rock, etc.), with coverage of no less than $5,000,000 combined single limit per occurrence and naming the City of Keene as an additional insured. Proof of insurance and endorsements must be submitted prior to permit issuance and renewed annually.

- Hours and acreage limits: excavation activities are limited to 7 a.m.–5 p.m., Monday–Friday; areas of unreclaimed, inactive and active excavation shall not exceed 12 acres at any one time; buffer areas shall not be used for storage of stumps, boulders or debris.

- Traffic and DOT coordination: the board included a requirement that, because the approved operation is larger than the originally permitted footprint, the applicant apply to the New Hampshire Department of Transportation for an updated driveway permit and communicate DOT recommendations to the board through community development staff. The board also included a contingency requiring a traffic management plan if traffic exceeds the thresholds cited in prior traffic memoranda.

Board members extensively discussed process concerns, public testimony timing and whether an alternate who sat on earlier hearings should vote. The board resolved a procedural dispute during deliberations and proceeded with the vote. Several board members and staff described the approval as the product of extended review and incorporation of recommendations from city and independent consultants. The applicant indicated willingness to comply with the adopted conditions; the applicant noted some measures (for example, insurance endorsements) may require coordination with subcontractors and insurers.

The board called the motion and approved PB‑2024‑20. The motion passed with one recorded vote in opposition. Staff will track condition compliance, the required monitoring reports, and any DOT responses as the excavation proceeds. The approval includes several precedent and subsequent conditions; the applicant must provide required permits, monitoring information and security before work begins.