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 requires licenses for water well contractors, drillers, pump installation contractors, and pump installers per MCA Title 37, Chapter 43.
License Categories
Fees
Exact fee amounts are set by the Board and posted in ARM 36.21. Contact the Board at 406-444-6643 for current fee schedules.
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
- Must employ licensed drillers for jobs
Water Well Driller (Rig Operator)
- 1 year supervised apprenticeship
- Pass state exam covering ARM 36.21, hydrogeology, drilling techniques
- Works under contractor\'s license or as independent contractor
Monitoring Well Constructor
- Similar requirements to well driller
- Specialized for observation/monitoring wells
- Must follow same construction standards
Continuing Education
- Required: Approved CE each renewal period
- Topics: Groundwater safety, hydrogeology, drilling technology, state standards
- Providers: Board-approved courses only (listed in ARM 36.21)
- Record retention: Keep certificates for 2–3 year renewal cycle for audit
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
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)
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
Groundwater Permits
Montana uses prior-appropriation for water rights:
- Exempt wells: ≤35 gpm and ≤10 acre-feet/year. No pre-drilling permit required, but owner must file Notice of Completion (Form 602) within 60 days of use.
- 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
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
Renew online through the DNRC portal before July 1 each year. Fees are set by the Board. You must complete required continuing education hours and provide proof before renewal. Licenses expire June 30; failure to renew by July 1 suspends the license, and over 30 days delinquent results in revocation.
The Board requires approved continuing education each renewal period. Exact hours and approved providers are specified in ARM Chapter 36.21. Topics emphasize groundwater safety, hydrogeology, drilling technology, and state drilling standards. Keep certificates for the entire renewal cycle for audit.
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.
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.
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Check out our Montana well guide for homeowners covering costs, permits, and water quality.
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