Do not dig the drainfield first. Idaho requires a permit before you construct, alter, or repair a subsurface system. Covering a system before the health district inspects it is how people buy a second system.
A new house, a shop bathroom, or a failed field all start in the same place: which office has authority over that parcel, then a design that matches the soil. Blackfoot Septic handles the design and installation and lines it up with the permit so the trench is not a guess. If the field is already failing, that path is often a permitted replacement — and a tank-open inspection is how we know which job you are buying.
Who actually permits the lot
- Most of Bingham County — including many lots around Blackfoot, Shelley, Firth, Aberdeen, and the rural roads between — Southeastern Idaho Public Health, Environmental Health. Bingham County office: 145 W Idaho Street, Blackfoot, ID 83221, (208) 785-2160. Current packets live on SIPH’s septic page. Staff names change; call the office for the person on permits this month.
- Inside a city sewer area — you may be required to connect rather than install septic. Ask the city’s public works, then SIPH. See sewer or septic.
- Fort Hall Reservation — the Shoshone-Bannock Tribal Water Resources Department permits septic systems. A SIPH form does not cover tribal land. See our Fort Hall tribal permits guide and the Fort Hall service page. We confirm jurisdiction before we schedule design work.
What SIPH will not take an incomplete file for
- A signed, dated application.
- A scaled plot plan: buildings, wells on this lot and the neighbors, water lines, tank, primary and replacement drainfields, ditches, canals, surface water within 300 feet, easements, slopes over 20%, and a north arrow.
- A copy of the warranty deed or tax notice. The permit is issued to the name on the deed.
- The fee. SIPH’s published numbers have disagreed between packets. Ask the Bingham County office for the current Board of Health fee before you write a check. Typical line items include a full permit, a tank-only permit, a speculative site evaluation, large systems, and renewal — the dollar amounts move.
Test holes are part of the application
Every application needs an onsite evaluation. The owner or applicant provides test holes a minimum of 8–10 feet deep, depending on soil, dug within about 50 feet of the intended drainfield and the replacement area. SIPH reads those holes for texture, limiting layers, and groundwater. Skip the replacement-area hole and you have skipped half the legal system.
The application also asks whether city sewer or a central collection line is 200 feet or less from the structure. Answer that honestly. It is one of the first questions that changes the whole project. Local soils, canals, and irrigation-season groundwater are why a neighbor’s system is not a template for yours.
After the permit is in hand
- Permits are typically valid for two years. Renew before they expire if the project slips.
- The permit is not transferable to a new owner or a different site.
- A homeowner may install a standard system on their own property with no hired help. The moment anyone else runs the machine, that person needs the right installer license. Complex systems — mounds, pressure distribution, package treatment — need a complex installer.
- Leave the system open for inspection. The as-built has to show the same setbacks the permit required.
Large systems (about 2,500 gallons per day or more) pull in a nutrient-pathogen evaluation, an Idaho-licensed engineer, and DEQ review. Shallow groundwater, coarse soils, and lots near the river can trigger that conversation even on a house. If that is your parcel, start with a site visit rather than a catalog system.
Ready to size it? Call (208) 980-7333 or read when a standard trench will not pass.