Ansom Outdoor
Septic · Wastewater · Potable

On-site wastewater built for mountain ground.

From cabin vaults to advanced treatment above 9,000 ft — full OWTS design with soils, layout, plans and profiles, county submittal, and honest quoting up front.

Septic quote — single-family

Get a structured, code-aware estimate in 60 seconds.

Jurisdiction: Clear Creek County
Recommended system
ATU + secondary dispersal (Level 2/3)
Required under Clear Creek County rules within source-water zones.
Design flow · tank
225 gpd
1250 gal tank min
Soil Treatment Area
375 sqft
~125 lf trench · Level 2
Estimated design fee
$14,340 – $32,265
Firm comparison: $71,700
All-in · 1.5× safety applied
Code pack applied — Clear Creek County
Clear Creek County Environmental Health + CDPHE Reg. 43
Setbacks (ft): well 100 · water 100 · lot line 25 · dwelling 20 · water line 25 · cut/bank 25
Permit fee: $850–$1600 · Review: 20–45 biz days
  • Source-water protection zone: 100 ft setback to Clear Creek and tributaries (stricter than Reg. 43's 50 ft baseline).
  • Level 2 treatment default; Level 3 within 300 ft of surface water or above 9,000 ft.
  • Percolation + soil profile pit both required; frost depth 42", design invert ≥ 48".
  • Steep-slope rule: > 30% grade requires engineered plan and geotechnical letter.
  • Van Eden Rd corridor: shallow bedrock and DG common — plan for pressure-dosed shallow bed or engineered mound.
Full calc breakdown — how each input drives 375 sqft STA and the final fee range
Step 1 · Design flow (Reg. 43 Table 6-1)
max(150, 3 BR × 75 gpd) = 225 gpd

Every added bedroom adds 75 gpd of design flow, which flows straight into tank size and STA area.

Step 2 · Septic tank (Reg. 43 §9)
3 BR base 1,000 gal + 250 gal ATU bump = 1,250 gal
Step 3 · Soil Treatment Area (Reg. 43 Table 10-1)
225 gpd ÷ 0.45 gpd/sqft (Decomposed granite (DG) LTAR) = 500 sqft base
× Level 2 credit (75%) = 375 sqft → ~125 lf @ 3-ft trench

Slower soil (lower LTAR) → bigger STA. Higher treatment level (2/3/4) shrinks STA 25 / 40 / 50%. Groundwater depth (8 ft) and shallow bedrock don't shrink STA — they push the recommendation toward a mound or ATU in Step 4.

Step 4 · System selection
ATU + secondary dispersal (Level 2/3) · complexity ×1.5

Required under Clear Creek County rules within source-water zones.

Driven by: elevation 8500 ft, slope 15%, groundwater 8 ft, shallow bedrock, within 300 ft of water, county default Level 2.

Step 5 · Design effort build-up
base effort (ATU): 52
+ plans/profiles/details: 10
+ perc & soil coordination: 6
+ county submittal & review response: 8
+ near-water setback analysis: 4
subtotal: 80 effort units
Step 6 · Site & jurisdiction multipliers
× system complexity: 1.50
× soil complexity (Decomposed granite (DG)): 1.10
× Clear Creek County review factor: 1.15
× bedroom factor (+8%/BR over 3): 1.00
× slope factor (15% → <20%): 1.00
× altitude factor (8500 ft → ≥8,500): 1.05
× safety: 1.50
= 239 design effort units
Step 7 · General estimate range
Ansom Outdoor: $14,340 – $32,265
Traditional firm comparison: $71,700

The range widens as complexity multipliers stack. Every input above nudges the effort total in Step 6, which scales the final estimate proportionally.

Sensitivity — flip an input, watch it move
  • Soil: LTAR drives STA linearly. Sand (0.80) needs ~211 sqft; clay (0.10) needs ~1688 sqft.
  • Slope: hits +8% at 20% grade, +15% at 30%. Also pushes system toward pressure-dosed at ≥20%.
  • Groundwater: <4 ft to seasonal high forces a mound (+35% effort).
  • Elevation: +5% effort at 8,500 ft, +10% at 9,500 ft (frost, ATU winterization).
  • Treatment level: each step up cuts STA (25 → 40 → 50%) but Level 3+ usually means ATU + higher base effort.

Estimate is design-only. Excludes county permit fees (shown above), soils lab, and construction.

Septic tank installation on a Colorado mountain property
What we design

Every OWTS a Colorado county will approve.

We handle the full civil scope for on-site wastewater and potable water in remote and mountain terrain — from a 2-bedroom cabin on shallow bedrock to a multi-unit lodge with an aerobic treatment plant and drip dispersal.

  • Conventional gravity OWTS — Septic tank + gravity distribution to a trench leach field. Best on gentle slopes with deep, well-drained soils.
  • Chamber / gravelless field — Plastic infiltrator chambers reduce trench footprint 30-50%. Great for tight lots and rocky ground.
  • Pressure-dosed bed — Pump vault + laterals for even distribution on marginal or shallow sites.
  • Elevated sand mound — Engineered mound over shallow bedrock or high groundwater. Common above 8,000 ft.
  • Advanced treatment (ATS) — Aerobic treatment unit + drip or subsurface dispersal. Required near lakes, streams, wells, or Level 2/3 treatment zones.
  • Vault / holding tank — Sealed vault with scheduled pumping for cabins, ADUs, or sites where dispersal is not permittable.
Deliverables

Plans, profiles, and the paperwork that goes with them.

Site plan (24×36)

Property, structures, well, setbacks, tank + field layout, staked coordinates. Branded title block.

Plans & profiles

Trench profiles with invert elevations, pipe sizes, slopes, and construction details for the installer.

Design report & permit

Soils logs, sizing calcs, code references, county application forms, and response to reviewer comments.

3D & pulled drawings

Existing civil / architectural drawings pulled from surveys, plus AI-assisted (Higgsfield + in-house) concept renderings.

As-built

Post-construction survey and record drawing for the county file and your closing binder.

Maintenance sheet

Owner-friendly one-pager: pump schedule, inspection ports, do's and don'ts.

Quick quote

Ballpark your septic design in 30 seconds.

All-in engineering fees, with a 1.5× safety factor already applied — the range you see is a number you can plan around, not a lowball. Design-only; excludes county permit fees, soils lab / percolation test, licensed installer bid, and construction.

Add-ons
Estimated design fee
$4,320 – $21,600
All-in fee range · 1.50× safety applied
Conventional gravity OWTS
Septic tank + gravity distribution to a trench leach field. Best on gentle slopes with deep, well-drained soils.
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Design fees only. Excludes county permit fees, soils testing lab work, and construction. Firm bid provided after a 30-minute site call.

Bring us the parcel and a rough site — we'll bring back a design you can build.

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