Water in, sewage out
City water and sewer, or your own well and septic?
Published · every figure below was checked against its primary source on the date shown.
Same house, two completely different utility problems
Water in and sewage out is one of the largest single variables in what a house costs to build here, and around St. Anthony it is decided almost entirely by which side of the city limits your lot is on.
What is striking is not just that the answers differ. It is that the two paths put the money and the paperwork at different points in the process, which changes what you need to have ready and when.
The two paths, and their timing
| Inside city limits | Outside, in the county | |
|---|---|---|
| Water | City water service, by application | A private well you drill and own |
| Sewage | City sewer, by application | An individual septic system |
| Who issues it | The city | Eastern Idaho Public Health, a separate agency |
| When it is due | Application and hookup fees paid before building permit approval | Septic permit required upon submittal of the building permit application |
| When you actually pay | At permit pickup, alongside the building permit fee | To the health district, on its own schedule |
| Cost certainty | A published fee you can ask for in advance | Site-dependent; the site evaluation decides the system |
Inside the city: a known number, paid early
The city's position is straightforward. If you are hooking into city water and/or sewer, the application for services and the hookup fees have to be paid before the building permit is approved. Then, when the permit is ready, payment for the building permit and the hookup fees is required at the time you pick it up.
The advantage of this path is certainty. It is a fee schedule, it is knowable in advance, and you can ring City of St. Anthony, 420 N Bridge Street Suite A, St. Anthony, ID 83445 — (208) 624-3494; inspections (208) 709-3030, 24 hours' notice and ask what it is for a given address before you commit to anything.
The thing to check is availability rather than price. Services reaching the street in front of a lot is not the same as services reaching the lot, and the cost of closing that gap can be substantial. Ask specifically.
Outside: a site-dependent number, tested early
In the county the sequence matters more than the amount, because the county has attached the septic permit to the moment of submittal:
“If you will be placing an individual septic system, you will need to complete a sewer application with Eastern Idaho Public Health District. The septic permit is required upon submittal of the building permit application.”
— Fremont County, Pre-Construction Check List for Building Permits, rev. 17 April 2026. Retrieved 14 August 2026
Upon submittal is the operative phrase. You cannot file the building permit application and sort the septic out during review.
Practically, that means:
- A site evaluation has to happen on the parcel, and it happens before you file anything with the county.
- The evaluation determines what kind of system the ground will take, and that determines the cost. A straightforward standard system and a complex alternative system are different orders of expense.
- The permit comes from Eastern Idaho Public Health, Fremont County office, 45 South 2nd West, St. Anthony — (208) 522-8065 — a different agency, a different file, a different queue from the building department.
- A well is a separate exercise again, and depth is not knowable until it is drilled.
None of that is a reason to avoid county ground. It is a reason to test the ground before you fall in love with it. The septic site evaluation is the single step in a rural build most capable of returning a genuine no, and it is comparatively cheap. Doing it first is the whole trick.
The order that keeps you out of trouble
- Establish which side of the city limits the parcel is on. Everything below follows from it.
- If inside: ask the city what water and sewer will cost at that specific address, and whether the services actually reach it.
- If outside: get the septic site evaluation done before anything else is designed or paid for.
- Price the well separately and honestly, as a range rather than a number.
- Only then let anyone draw a plan against the site.
Related reading on this site
- Building on inherited or farm ground — where the septic step sits in the wider order of operations
- St. Anthony issues its own building permits — the boundary that decides which utility path you are on
- What it costs to build a custom home in St. Anthony — how utilities sit against the other movable costs
Common questions
Will I be on city water and sewer or a well and septic in St. Anthony?
It depends which side of the city limits the lot is on, and on whether city services actually reach it. Inside the city, the permit path assumes city water and sewer and requires the hookup fees to be paid before the building permit is approved. Outside, you are on a private well and an individual septic system.
When do I have to pay the city hookup fees?
Before building permit approval. The city's application says that if you are hooking into city water and/or sewer, the application for services and the hookup fees must be paid prior to building permit approval — and that payment for the building permit and hookup fees is required at the time the permit is picked up.
When do I need the septic permit in the county?
At submittal. The county's checklist states the septic permit is required upon submittal of the building permit application. That means the site evaluation and the septic application come before you file, not after.
Who issues the septic permit?
Eastern Idaho Public Health, which is a separate agency from the county building department and works on its own file and its own timeline. The Fremont County office is at 45 South 2nd West in St. Anthony, on (208) 522-8065.
Which is cheaper overall?
There is no honest general answer. City hookup fees are a known figure you can ask for; a well and a septic system are site-dependent costs that can vary by many thousands of dollars depending on depth, soil and the system the site evaluation requires. Get both priced for your actual parcel rather than reasoning from averages.
Can I put in a well inside the city limits?
Ask the city. That is a question about city policy and about what services are available at that address, and the city office is the only place that can answer it for a specific parcel.
What if city services are nearby but not at my lot?
Then the question becomes who pays to bring them, and how far. That is a conversation to have with the city office before you buy, because the answer can be a large number and it attaches to the land rather than to you.
How long does a septic site evaluation take to arrange?
That depends on the health district's workload and on the season — evaluations need ground you can actually dig and read, which narrows the window in a valley with real winters. Because the county requires the septic permit at submittal rather than later, a slow evaluation delays your entire building permit, so start it earlier than feels necessary.
Ask about a build in St. Anthony
Describe the parcel and roughly what you have in mind. What comes back is an honest read on which firms here take that kind of work, plus the one thing most people have not established yet: whether the city or the county will be reviewing your plans. Free, and nothing automated ever follows.
- Say where the ground is and what you intend to put on it.
- You are pointed toward the firms in this town with that work behind them.
- From there it is between you and them. No commission, no introduction fee, and nobody standing between you and your own contract.
One contact method is plenty — whichever you prefer. A human being writes back.