Off-Grid Living in Mercer County, Pennsylvania

I'll be upfront: Mercer County, Pennsylvania is one of those places where the county itself doesn't set most of the rules that matter to off-grid living. There's no countywide zoning ordinance here. About 30 of the county's 48 townships and boroughs have adopted their own zoning, and the other 18 or so don't, so whether you can just buy raw land and live on it off-grid depends almost entirely on which specific municipality the parcel sits in. The Mercer County Regional Planning Commission (MCRPC) coordinates planning but doesn't zone anything itself, and it directs people to the local Zoning Officer for real answers.

Same pattern with septic. Pennsylvania's Sewage Facilities Act (Act 537) requires a "local agency" to permit on-lot sewage systems, but in Mercer County that agency is the municipality, acting through a Sewage Enforcement Officer (SEO), not a county health department. So if you're planning a septic system, composting toilet, or greywater setup, you need to find out who your township's or borough's SEO is and go through them. I didn't find any Mercer-specific ordinance on greywater or composting toilets, so both default to the state baseline: greywater is legally treated like sewage under Act 537, and composting toilets are expected to meet NSF Standard 41.

Building permits follow the state's Uniform Construction Code (UCC), which Pennsylvania has enforced since 2004. Locally, the Mercer County Regional Council of Governments (MCRCOG) coordinates UCC administration, but actual permit issuance and inspections happen at the municipal level, sometimes through a contracted third-party agency. There's no Mercer-specific rule I found on tiny homes or RVs as permanent dwellings either; that again falls to whatever zoning and UCC provisions the specific township applies (or doesn't, if unzoned).

Wells are more straightforward: Pennsylvania doesn't require a state well permit, though licensed drillers do the work, and Mercer County's own guidance is honest that private wells are largely unregulated and that DEP has limited power if a neighbor's well starts competing with yours for groundwater. The Mercer County Conservation District can offer technical help on water and soil questions but isn't a permitting office for wells.

Rainwater harvesting appears permitted for non-potable uses under the state baseline, though I found nothing confirming it as an approved sole water supply for a permanent residence here.

On utility disconnection, there's no countywide requirement to hook up to the grid, and no state law mandates it either. But since occupancy conditions are set locally, a certificate of occupancy in a zoned municipality could still require utility connections; you'd need to ask that specific township or borough's code office.

Bottom line: in Mercer County, "it depends on your township" isn't a dodge, it's the actual legal structure. Start every question with the local zoning officer and SEO before assuming anything.