Basics: Private Well vs. Municipal Water
Montana law requires a water supply for any new home. If public water is not available, a private well is needed. If municipal lines reach your property, connection is often required.
If municipal water lines don't reach your property (common in rural Montana):
- You must install a private well
- Most rural Montana homes rely on wells
- Septic system also required
If public water lines reach your lot:
- Connection typically required by local ordinance
- Usually cheaper than drilling if lines are nearby
- Example: West Yellowstone requires connection
Well Drilling Costs in Montana
Comparing against national numbers? See our national guide to the cost to drill a water well for per-foot rates, itemized components, and what quotes leave out.
A complete private well system in Montana typically costs $10,000–$30,000, depending on depth, geology, and casing material.
Timeline: From Decision to Drinking Water
Expect 2–6 weeks from your first call to potable water. Drilling itself takes only 1-4 days for most domestic wells.
Permits & Process
Do You Need a Permit?
≤35 gallons per minute AND ≤10 acre-feet/year
- No pre-drilling permit required
- File Form 602 within 60 days after first use
- Filing fee: $250
- Secures your groundwater certificate
>35 gpm OR >10 acre-feet/year
- File Form 600 (Beneficial Water Use Permit) before drilling
- Processing time: 2–6 months
- Public notice process
- Required for large irrigation, commercial wells
Step-by-Step Process
- Contact a Licensed Drilling Contractor. Montana requires licensed drillers for all wells.
- Site Selection. Mark well location (avoid septic, property lines).
- Check Water Rights. Determine if Form 600 permit needed (if >35 gpm) or just Form 602 (if exempt).
- Drilling the Well. Licensed driller drills, installs casing, develops well per state standards.
- Pump Installation. Set submersible pump, connect wiring, disinfect well.
- Water Testing. Collect samples and send to certified lab.
- File Reports:
- Driller files Well Log (Form 603) to MBMG within 60 days
- Owner files Form 602 to DNRC within 60 days after first use
Who Does What?
Driller Handles:
- State licensing (DNRC BWWC)
- Drilling, casing, grouting
- Well construction standards
- Well log report (Form 603) to MBMG
Homeowner Handles:
- Water-right paperwork (Form 602 or 600)
- Paying fees ($250 for Form 602)
- Water testing (homeowner expense)
- Any local permits (COSA, building)
Water Quality
Well water testing in Montana
The MSU Extension Well Educated program handles private well water quality in Montana. Montana recommends annual bacteria and nitrate testing, with a full-panel test the first time. In Well Educated program data, about 10% of Montana wells exceed health thresholds for arsenic or manganese.
Free or low-cost testing: The Well Educated program provides discounted test kits (sometimes free through county cost-share) via participating county Extension offices.
Not sure what to test for? See our national guide to well water testing or order a certified lab test kit shipped to your door.
Recommended Testing Schedule
- Annually: Total coliform bacteria, nitrate (EPA also recommends TDS and pH)
- At Well Install: Full suite (hardness, iron, manganese, arsenic, metals, TDS, pH)
- Every 3–5 years: Repeat multi-parameter panel
- After any event: Illness, flooding, plumbing changes, taste/odor changes
Common Montana Water Quality Issues
Bacteria
About 25% of Montana wells have total coliform; ~3% have E. coli. Indicates surface intrusion. Requires disinfection.
Nitrate
~3% of Montana wells exceed 10 mg/L limit. From livestock/fertilizer. Concern for infants and pregnant women.
Arsenic
~10% of wells exceed health standards. Natural from deep bedrock. Carcinogenic long-term. Test at install.
Manganese
~10% of wells above health standards. Causes staining and neurological concerns. Natural geologic source.
Iron & Hardness
Very common. Iron causes reddish staining. Hardness (calcium/magnesium) causes scale. Water softeners are common solutions.
Regional Hotspots
- Arsenic: Higher in southwestern Montana, Madison/Missouri systems, north-central ranges
- Nitrate: Irrigated valleys (Flathead, Missoula, Yellowstone Valley, Judith Basin), eastern plains
- Interactive maps: MSU Well Educated Water Quality Atlas
Treatment Options
| Issue | Treatment |
|---|---|
| Bacteria/E. coli | Shock chlorination, UV lamp, continuous chlorinator |
| Nitrate | Reverse osmosis, distillation (point-of-use) |
| Arsenic | Reverse osmosis, iron-oxide adsorption filters |
| Iron/Manganese | Oxidizing filters (greensand/Birm), chlorination |
| Hardness | Water softener (ion-exchange with salt) |
Maintenance & Troubleshooting
Annual Maintenance Checklist
- Test water for coliform and nitrate annually
- Ensure wellhead has sanitary cap (screened vent)
- Check pressure tank air charge (30-50 psi typical)
- Grade soil away from wellhead (no puddles)
- Keep hazards 100-250 ft away (fertilizer, fuel tanks)
- Check pressure gauge monthly (40-60 psi typical)
Warning Signs of Well Problems
- Loss of pressure/flow: Check tank switch and pump fuses first
- Pump runs continuously: Leak in line or waterlogged pressure tank
- No water: Check electrical; if working, well may be dry
- Cloudy/milky water: Air in lines or sediment entering well
- Rusty/colored water: High iron/manganese or corroded plumbing
- Foul odor/taste: Bacteria (hydrogen sulfide) or high sulfate – disinfect and test
DIY vs. Professional Help
You Can Handle:
- Water testing (collecting samples)
- Filter cartridge changes
- Shock chlorination
- Basic plumbing under sinks
- Clean surroundings
Call a Professional For:
- Drilling or deepening well
- Pump/tank replacement or repairs
- Electrical wiring to pump (licensed electrician)
- Major leaks or unclear problems
- Treatment system installation
Find a Licensed Driller
Montana law requires a licensed water well driller for all well work.
Search Licensed Drillers in Montana
Find Drillers Near You →How to Verify a Driller
- Contact DNRC Board of Water Well Contractors: 406-444-3111
- Ask for driller's license number and verify status
- Get 2-3 written quotes
- Ask for references from recent jobs
- Ensure driller provides signed well log (Form 603)
Resources & Contacts
DNRC Regional Water Offices
- Billings – 406-247-4415
- Bozeman – 406-586-3136
- Glasgow – 406-228-2561
- Havre – 406-265-5516
- Helena – 406-444-6999
- Kalispell – 406-752-2288
- Lewistown – 406-538-7459
- Missoula – 406-721-4284
Certified Testing Laboratories
- Mission Mountain Laboratories (Arlee) – 406-745-5227
- Energy Laboratories (Billings) – 406-252-6325
- Bridger Analytical Lab (Bozeman) – 406-582-0822
Key Forms & Documents
Frequently Asked Questions
Are You a Licensed Driller?
Check out our compliance reference for Montana drilling regulations, licensing, and construction standards.
Montana Driller Compliance Guide →Sources & References
All facts in this guide are sourced from official Montana government agencies and university research:
- West Yellowstone Municipal Code §13.04 – Connection requirements
- Montana DEQ – COSA (Certificate of Subdivision Approval)
- 2024 Well Drilling Cost Averages
- Chambers Drilling Montana FAQs
- Montana DNRC – Exempt Well Requirements
- MSU Extension – Well Owner Responsibilities
- MSU Extension – Testing Private Well Water Quality
- MSU Well Educated – Data and Results Summaries
- EPA – Protect Your Home's Water
- Gallatin Local Water Quality District – Well Maintenance
- Montana Board of Water Well Contractors
- DNRC Regional Water Offices
- MSU – Certified Montana Drinking Water Labs
- DNRC – Water Right Forms and Resources
- Montana Water Well Drillers Association