Brookline asks Mason Planning Board to probe traffic and water risks tied to proposed Onyx quarry

Town Planner Michele Decoteau told the Selectboard on June 22 that the Onyx (Mason) gravel pit application’s traffic study omitted critical data, used erroneous Route 101 figures from Wilton, and failed to break out heavy-vehicle traffic counts. She and staff also raised the prospect that trucked water used for dust control could introduce contaminants to Brookline’s water supply if not handled correctly.

The planner prepared a draft letter for the board to send to the Mason Planning Board outlining road-safety and water-contamination concerns. Board members expressed frustration that the traffic study did not include site-specific heavy-truck figures and that Mason Road and other town roads could suffer pavement damage that would be costly to repair. Brian Rater noted sections of Mason Road require repaving — a localized estimate of $30,000 was cited for identified sections — and expressed concern the town would have no reliable way to recover those costs if heavy trucks increase.

After discussion, the Selectboard authorized Brian Rater to sign the letter to the Mason Planning Board raising those concerns; the motion passed 5-0. The minutes show that Mason’s planning board meets June 24 and that the town requested to be included in future reviews if the quarry plan advances.

The board did not set weight limits at the meeting, with staff noting that establishing legal weight limits is complicated and requires further technical review. The Selectboard asked staff to continue documenting road conditions with NRPC data and to press for a seat at future Mason Planning Board reviews if the Onyx application proceeds.