Off-Grid Living in Silver Bow County, Montana

Silver Bow County is a special case in Montana: it's not a typical county government but a consolidated city-county, "Butte-Silver Bow." That means there's one Planning Department, one Building & Code Enforcement office, and one Health Department covering both the city of Butte and all the surrounding unincorporated land. If you're used to hearing that Montana counties often have no zoning, don't assume that here, Butte-Silver Bow has adopted unified zoning (Title 17 of its municipal code) covering the whole jurisdiction, and it's currently being rewritten by the Planning Department and a consultant, so district-level rules could shift.

On building, Butte-Silver Bow has opted into full local code enforcement, adopting the 2021 IRC, IBC, and related codes, with permits required for residential, mechanical, plumbing, and other work. This is stricter than the state's general exemption for some single-family construction, since the local government here has taken over full jurisdiction and reports compliance to the state.

Septic systems go through the Butte-Silver Bow Environmental Health Division, which requires a permit for any structure with onsite wastewater disposal, enforcing state DEQ Circular 4 and ARM standards locally. I did not find anything specifically addressing composting toilets as a stand-alone system, so if that's your plan, ask Environmental Health directly rather than assuming it's covered.

Greywater and rainwater harvesting: I couldn't find county-specific ordinances for either. That likely means the state's general baseline applies (no state prohibition found on rainwater collection), but since nothing local was confirmed, don't take my word as final, ask the Health Department for greywater and check with Planning if you want zoning-level certainty.

Wells are where this county gets genuinely tricky. Silver Bow contains a state-designated Controlled Groundwater Area (the East Valley CGWA), and inside it, new groundwater appropriations must be approved by the Butte-Silver Bow Board of Health acting as the Water Quality District, not just filed as a standard exempt well. Outside that zone, Montana's usual exempt-well process (a Notice of Completion, DNRC Form 602, filed after you start using the water) would apply. Given how much this can vary block to block, confirm with both DNRC and the local Board of Health before drilling.

On living off-grid generally: nothing explicitly bans disconnecting from utilities, but because building permits, code compliance, and wastewater permitting are all mandatory here, a legal dwelling still has to meet code requirements for water and sewage, whether or not it's tied to a municipal grid. Off-grid power itself isn't directly restricted in anything I found.

Bottom line: this is a jurisdiction with real teeth on permitting, more like a small city than a rural county. Call ahead before you commit to a plan.