Forms & Resources
Well Log Report (Form 603)
Required for every completed well. Due within 60 days.
Submit to MBMG GWIC online or mail. Provide copy to owner.
Submit Online (GWIC) ↗Abandonment Report
Required when abandoning/plugging a well. Due within 60 days.
Must include full description of abandonment procedures per ARM 36.21.810.
Submit to GWIC ↗Online Submission
Use the MBMG Ground Water Information Center (GWIC) online portal for electronic filing of Form 603 and abandonment reports. Create an account and upload well logs directly.
License Renewal: Submit your annual license renewal and payments online through the DNRC state account portal.
Licensing Requirements
Montana licenses water well contractors, water well drillers and monitoring well constructors per MCA Title 37, Chapter 43.
License Categories
| License Type | Fee | Term |
|---|---|---|
| Water Well Contractor | $575 | 1 year (July 1–June 30) |
| Water Well Driller | $475 | 1 year (July 1–June 30) |
| Monitoring Well Constructor | $575 | 1 year (July 1–June 30) |
Fees
The June 2025 examination application and 2026–27 renewal package list WWC/MWC $575 and WWD $475; dual WWD/MWC renewal is $575 and inactive status $250. A $150 late fee applies July 10. WWC and MWC require a $25,000 bond or Board-approved equivalent; one covers multiple categories. Government-bonded state/federal employees are exempt during that employment, and firms with more than two WWC/MWC licensees may use one $25,000 firm bond (MCA 37-43-306). Inactive licensees owe $250 without bond or CE. WWD must be employed by a licensed contractor.
License Requirements
Water Well Contractor (Firm License)
- At least 1 year practical experience under supervision
- Pass state oral/written exam (MCA 37-43-305)
- Knowledge of state water laws, sanitary standards, geology, construction methods
- May contract for well drilling; requires adequate equipment and financial responsibility
Water Well Driller (Rig Operator)
- 1 year supervised apprenticeship
- Pass state exam covering ARM 36.21, hydrogeology, drilling techniques
- Must be employed by a licensed water well contractor
Monitoring Well Constructor
- Similar requirements to well driller
- Specialized for observation/monitoring wells
- Must follow same construction standards
Continuing Education
- Required: 4 Board-approved credits each July 1–June 30 license year, with no carryover (inactive status exempt)
- Topics: Groundwater safety, hydrogeology, drilling technology, state standards
- Providers: Board-approved courses only (listed in ARM 36.21)
- Record retention: Keep a record of course completion
Exam Information
Exams are oral and/or written, administered by DNRC per Board schedule. The Board may waive exam/apprenticeship for out-of-state licensees if standards are equivalent (reciprocity).
Reporting & Documentation
| Document | Deadline | Submit To |
|---|---|---|
| Well Log Report (Form 603) | 60 days after completion | MBMG GWIC + copy to owner |
| Abandonment Report | 60 days after abandoning | MBMG GWIC (full description) |
| License Renewal | Before July 1 annually | DNRC online portal |
| CE Certificates | Keep for renewal cycle | Keep completion records |
Well Log Requirements (Form 603)
The well log must include:
- Depth and lithology (formation descriptions)
- Water-bearing zones encountered
- Casing sizes, materials, and depths
- Grouting/sealing information (per ARM 36.21.654)
- Pump test data (if conducted)
- Location (Section-Township-Range or GPS coordinates)
Record Retention
Licensed drillers/contractors must retain copies of all well logs and reports in their files per ARM 36.21.639(2). Keep license bond and CE documentation on file for the renewal cycle.
Abandonment Reporting
When abandoning a well, submit a full description of abandonment procedures to MBMG GWIC within 60 days (ARM 36.21.810). Include:
- Method used (grout from bottom-up, casing removal, etc.)
- Materials used for sealing
- Final surface completion (cut casing 3 ft below grade, backfill)
Construction Standards (ARM 36.21)
Casing Requirements (ARM 36.21.641A)
All wells must be cased to the bottom of the usable drill hole and sealed per ARM 36.21.654.
- Materials: Steel or schedule-40 PVC (sufficient diameter and depth to prevent collapse)
- Overlap: If stepping down casing diameter, minimum 4 ft overlap required
Annular Seal/Grouting (ARM 36.21.654)
- Minimum 25 ft consolidated seal above screen or bottom of casing
- Seal materials: cement/bentonite grout, placed bottom-up without gaps
- Minimum 3-inch thickness of grout in annular space
- Minimum 1.5-inch around casing
- Cable-tool wells: continuous bentonite feed during drilling
- Preserve confining layers with permanent seals
Setback Requirements (ARM 36.21.638)
| Contamination Source | Minimum Distance |
|---|---|
| Septic tanks, USTs, fuel lines | 50 ft minimum |
| Drainfields, seepage pits, cesspools | 100 ft minimum |
| Sewage lagoons (regulated) | 1000 ft minimum |
| Property lines (unless easement) | 10 ft recommended |
| Pressurized sewer mains | 10 ft (50 ft for other sewers) |
Local Ordinances
Always check local wellhead-protection or floodplain ordinances. Designated Wellhead Protection Areas or Controlled Ground Water Areas may have additional requirements.
Disinfection
Wells must be disinfected (shock-chlorinated) after drilling/completion. Standard practice is to circulate chlorine solution through the well and flush to waste before bacteriological testing.
Permits
Form 602I is limited to groundwater, ≤35 gpm and ≤10 acre-feet per calendar year per project, requires ownership in the place of use when filed, and is not for a Controlled Groundwater Area unless DNRC instructs otherwise. Other exceptions (including compact-area Form 645, geothermal Form 646 and emergency-fire Form 647) have separate fees.
Groundwater Permits
Montana uses prior-appropriation for water rights:
- Exempt wells: ≤35 gpm and ≤10 acre-feet/year. Since January 1, 2026, file Form 602I ($400) and obtain DNRC authorization before putting water to use; the NOI may be filed before or after drilling. Then file Form 602 ($250). DNRC has a 5-year completion window after authorization; its Permit Exceptions page also directs filing within 60 days of first use. Confirm the applicable deadline with the regional office. Total DNRC filing fees: $650.
- Permitted wells: >35 gpm or >10 acre-feet/year. Requires Beneficial Water Use Permit (Form 600) from DNRC before drilling. Processing time: 2–6 months.
No State Drilling Permit
Montana does not require a separate "drilling permit" from the state for exempt wells. However:
- Landowners drilling on their own property for domestic/ag use must obtain a permit from the Board before drilling (MCA 37-43-302)
- Counties cannot impose their own drilling permits beyond state law
- Local building departments may require plumbing/electrical permits
- Subdivision approval (COSA) required for new lots (<20 acres) from DEQ
Special Well Types
- Monitoring wells: Require Monitoring Well Constructor license. No special permit beyond driller license, but must follow construction standards.
- Geothermal wells: Treated as water wells, requiring licensed driller and compliance with ARM 36.21 standards.
Drilling Conditions by Region
Eastern Plains
- Deep sedimentary basins (Fort Union, Fox Hills, Hell Creek formations)
- Thick glacial/alluvial fill
- Typical depths: 100–500 ft
- Yields vary, moderately porous
Central Montana (Hi-Line)
- Glacial outwash aquifers
- Fractured Cretaceous bedrock (Fox Hills, Judith River)
- Variable yields
- Watch for artesian conditions
Western Montana Valleys
- Shallow alluvial sands/gravel (Flathead, Bitterroot, Clark Fork)
- Fractured crystalline bedrock (granite, schist, Belt Supergroup)
- Typical depths: 50–200 ft into alluvium
- Good yields in valley fill
Mountain/Rocky Mountain Front
- Bedrock wells in Paleozoic limestones and Cretaceous formations
- Artesian/flowing wells common (Madison, Fox Hills zones)
- Hard rock requiring coring or hammering
- Yields from fissures and fractures
Seasonal Factors
Montana winters freeze ground deeply (4+ ft in plains, more in mountains). Rigs may need mud heaters or target ice-free seasons. Spring thaw raises water tables significantly in alluvial aquifers. Summer dry periods lower water tables and reduce recharge.
Special Challenges
- Hard rock: Mountain areas hit bedrock quickly. Wells often cored or hammered, yield from fissures.
- Unconsolidated aquifers: Valleys with deep sands/gravel may require long, large-diameter casing and gravel packs.
- Artesian/flowing wells: Many Western MT wells tap confined aquifers under pressure. Special capping or pumping procedures may be needed (ARM 36.21.671).
- Contaminants: Urban/industrial sites (mining, landfill areas) may require drilling in difficult or regulated materials.
Resources & Contacts
DNRC - Board of Water Well Contractors
Licensing, standards, compliance questions
Montana Bureau of Mines & Geology (GWIC)
Well log submission and retrieval
Montana DEQ - Drinking Water Section
Public water well regulations (reference)
Montana Water Well Drillers Association
Industry association, networking, technical info
Regulatory References
- MCA 37-43-301 – Licensed person to supervise all construction
- MCA 37-43-302 – License required (including owner-drilling exemption)
- MCA 37-43-305 – Examination and qualifications
- ARM 36.21.641A – Casing depth requirement
- ARM 36.21.654 – Casing/seal details
- ARM 36.21.638 – Well location setbacks
- ARM 36.21.639 – Well log submittal rules
- ARM 36.21.810 – Abandonment (reporting & methods)
Frequently Asked Questions
How do I renew my Montana driller license?
Renew online through the DNRC portal before July 1 each year. WWC and MWC fees are $575; WWD $475 (2026–27 package). Complete 4 Board-approved CE hours each license year with no carryover (inactive status requires no bond or CE). Licenses expire June 30; not renewed July 1 means suspension, a $150 late fee applies July 10, and nonrenewal by August 1 means revocation and a new application/exam.
What are the CE requirements for Montana drillers?
For active licenses, the Board requires 4 approved continuing education credits per license year (July 1–June 30), with no carryover. Topics emphasize groundwater safety, hydrogeology, drilling technology, and state drilling standards. Keep certificates for the entire renewal cycle for audit.
How soon must I file the well log?
Within 60 days after completion. Submit Form 603 to MBMG GWIC online or by mail. Provide a copy to the well owner. The log must include depth, lithology, water-bearing zones, casing details, grouting, and any pump test data.
What are the setback requirements in Montana?
50 ft from septic tanks/USTs, 100 ft from drainfields/cesspools, 1000 ft from regulated sewage lagoons, and 10 ft from property lines (unless easement). Additional restrictions apply near pressurized sewers. Always check local wellhead protection ordinances.
Looking for Homeowner Information?
Check out our Montana well guide for homeowners covering costs, permits, and water quality.
Montana Homeowner Well Guide →