DEQ Clears Subdivision Near Big Sky for Water and Wastewater Facilities

The Montana Department of Environmental Quality (DEQ) has released its final Environmental Assessment (EA) for the implementation of drinking water, stormwater, and wastewater facilities at the Quarry Phase II subdivision near Big Sky, Montana. Dated April 29, 2025, the report confirms that the proposed facilities meet the requirements of the Montana Environmental Policy Act while posing no significant environmental threats.

This decision is a key step for Big Sky Rock, LLC, which sought approval for a Certificate of Subdivision Approval (COSA) to progress with installing essential utilities for the upcoming residential development. Big Sky Rock, LLC’s application was given the green light by Gallatin County Platting and Planning on April 16, 2024, predicated on significant infrastructural considerations.

The planned infrastructure includes:

• Water service connections via the existing Lazy J Utility Association facilities, involving main extensions to service the proposed subdivision’s lots.
• Individual Level 2 wastewater treatment systems and drainfields for each of the four lots, designed to effectively reduce nitrogen levels before soil treatment.
• Stormwater management facilitated through onsite retention ponds, swales, and an integrated system of gutters, sewers, and manholes to ensure treated, retained, and infiltrated stormwater in compliance with approved standards.

The DEQ highlighted the inclusion of comprehensive responses to substantive matters raised during the public commentary period, assuring stakeholders that potential environmental impacts had been thoroughly assessed and addressed.

For those interested in exploring the full details of DEQ’s findings and the implications for the Quarry Phase II subdivision, the final Environmental Assessment is available on the DEQ’s website.