

Septic Systems in Montana
Septic Systems contractors in Montana
Conventional, chamber, mound and aerobic systems installed to the approved design, with the health department inspection before backfill.
Project guide
Hiring septic systems contractors in Montana
Septic contractors install and replace the tank, distribution box and drain field that treat wastewater on properties without sewer. Nothing goes in the ground until a soil evaluation or percolation test has been done and the county or state health department has approved a system design; the installer builds to that design and the inspector looks at the open trenches before they are covered. Conventional gravel-and-pipe drain fields are the least expensive where soil drains well, but heavy clay, high water tables and small lots push jobs toward chambers, sand mounds, drip dispersal or an aerobic treatment unit, each with a different price and maintenance schedule. Most states license septic installers separately from general contractors, and many require a pumping and inspection record at property sale.
GradeLine lists 122 septic systems contractors that serve Montana.Compare their work and equipment, then confirm availability and service area before requesting a quote.
Listed businesses are based in Columbia Falls, Frenchtown, Manhattan, Belgrade, Havre, Ronan, though most crews travel well beyond their home city.
What septic systems work costs
A conventional gravity system on well-draining soil typically runs $5,000 to $12,000 installed. Chamber and pressure-dosed systems land in the $8,000 to $18,000 range, and mound or aerobic treatment systems commonly cost $15,000 to $35,000 because of the extra fill, pumps and electrical work. The soil evaluation and design usually add $500 to $2,000 up front.
Ranges are national and approximate; regional labor rates, material prices and site conditions move them in both directions.
Common projects
- New conventional and chamber systems for new construction and additions
- Drain field replacement, tank replacement and system upgrades when a field has failed
- Mound, aerobic and engineered systems for poor soil, high water table or small lots
What affects a quote
- System type and size, which the design sets by bedroom count and the soil evaluation
- Depth to seasonal high water table or rock, the amount of fill or sand required, and haul distances
- Tank material and access, pump and alarm components, and the cost of the design, permit and inspections
Septic Systems FAQ
What does septic systems work cost?
A conventional gravity system on well-draining soil typically runs $5,000 to $12,000 installed. Chamber and pressure-dosed systems land in the $8,000 to $18,000 range, and mound or aerobic treatment systems commonly cost $15,000 to $35,000 because of the extra fill, pumps and electrical work. The soil evaluation and design usually add $500 to $2,000 up front.
What should I share when requesting a septic systems estimate?
Pull together any existing septic permit or as-built drawing, the plot plan showing the well, house and property lines, the bedroom count, and any recent inspection or pumping record.
What can change the cost of septic systems work in Montana?
The main cost items are system type and size, which the design sets by bedroom count and the soil evaluation; depth to seasonal high water table or rock, the amount of fill or sand required, and haul distances; tank material and access, pump and alarm components, and the cost of the design, permit and inspections. A site visit helps the crew see which ones apply.
Do septic systems projects in Montana need permits?
Every state requires a permit for new or replacement septic systems, issued by the county or state health department after a soil evaluation and design review. Setbacks from wells, streams and property lines are fixed by code, and the system must be inspected before the trenches are backfilled.
Directory
Septic Systems contractors serving Montana
122 contractors found


Caddis Excavation
Frenchtown, MTMissoula County
demolition, driveways, erosion control, excavation, foundations, grading

G.B.C. Ground Breaking Construction
Frenchtown, MTMissoula County
demolition, excavation, foundations, grading, septic systems
22 years in business


Keystone Contracting
driveways, erosion control, excavation, foundations, grading, hauling trucking

Tom Patrick Construction
Havre, MTBlaine County
demolition, driveways, excavation, grading, hauling trucking, paving prep

Hillside Excavation LLC
Ronan, MT
driveways, excavation, foundations, hauling trucking, retaining walls, septic systems

Grosvold Logging & Excavating
Anaconda, MTDeer Lodge County
demolition, excavation, foundations, hauling trucking, septic systems, site prep

TLC Septic & Excavation Inc
Belgrade, MT
driveways, excavation, foundations, hauling trucking, septic systems, trenching underground

Massey Excavating
Kalispell, MT
demolition, excavation, foundations, grading, pond water management, septic systems

Watson Excavating, Inc.
Columbia Falls, MTFlathead County
demolition, excavation, foundations, land clearing, septic systems, site prep

Holden Excavating
excavation, grading, hauling trucking, septic systems, site prep

Rimrock Dirtworks
demolition, excavation, foundations, grading, hauling trucking, land clearing


Griffith Contracting, LLC
Lewistown, MTFergus County
demolition, excavation, foundations, grading, hauling trucking, pond water management

DY Excavating
driveways, erosion control, excavation, foundations, grading, hauling trucking

Trenchless Solutions
Missoula, MT
driveways, excavation, retaining walls, septic systems, trenching underground

Legacy Land Services
excavation, grading, land clearing, retaining walls, septic systems, site prep


Tom Roe & Son Construction Inc.
Big Timber, MTSweet Grass County
excavation, pond water management, septic systems
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