How Much Does a Septic System Cost in Colorado?
It's the first question almost every homeowner asks: what's a new septic system going to cost me? The honest answer is that it depends — but in Colorado, most residential septic installations fall between $8,000 and $30,000+, with a typical conventional system landing somewhere in the $12,000–$20,000 range.
That's a wide range, and the reason is that no two properties are the same. Below we break down exactly what drives the price so you can budget realistically for your Northern Colorado property.
Typical Colorado Cost Ranges
Conventional gravity system: $8,000–$18,000. Engineered / mound / aerobic system: $18,000–$30,000+. Tank-only replacement: $3,000–$7,000.
6 Factors That Determine Your Price
System Type
A conventional gravity system is the most affordable. Engineered systems — mound, aerobic treatment units (ATUs), or pressure-dosed systems required by tougher soils or high water tables — cost significantly more.
Soil & Percolation
A perc test determines how well your soil drains. Rocky, clay-heavy, or slow-draining soil (common in Northern Colorado foothills) may require a more complex, more expensive system design.
Tank Size & Material
Tank size is dictated by the number of bedrooms. Concrete, fiberglass, and plastic tanks vary in price and longevity.
Lot Size, Access & Terrain
Steep, wooded, or rocky mountain lots around Red Feather Lakes or Estes Park cost more to excavate than a flat, open lot. Difficult access for equipment adds labor.
Permits & Inspections
Larimer, Weld, and Boulder counties each require permits, soil evaluations, and final inspections. These fees are part of every legitimate install.
Drain Field Size
Larger homes and slower soils need bigger leach fields, which means more excavation, more material, and higher cost.
Why Mountain Properties Cost More
If you own property in Red Feather Lakes, Livermore, Glen Haven, or the Estes Park area, expect to be at the higher end. Rocky soil is harder and slower to excavate, steep terrain complicates the drain field layout, and remote access adds equipment and labor time. These aren't upsells — they're the real cost of building a system that will last in that environment.
What's Included in a Proper Installation
- Soil evaluation and percolation testing
- County permitting and engineered design (when required)
- Excavation of the tank pit and drain field
- Supply and installation of the tank and distribution system
- Backfilling, grading, and site cleanup
- Final county inspection and sign-off
Be cautious of any quote that's dramatically lower than the rest — it often means skipped permits or cut corners that cost far more when the system fails or won't pass inspection.
The best way to know your real cost is a site visit and soil evaluation. We give honest, itemized estimates so you know exactly what you're paying for — no surprises, no hidden fees.
Planning a Septic Install?
Get a Free, Itemized Estimate
We install septic systems across Loveland, Fort Collins, Greeley, Red Feather Lakes, Estes Park, and all of Northern Colorado. Call for a site visit and honest quote.
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