New Septic Installation in Colorado County, Texas
Licensed, bonded septic system installation for Colorado County — Columbus, Eagle Lake, Weimar, Garwood, Alleyton, Sheridan and the surrounding rural communities.
Licensed & Bonded
Texas OSF installer
Permitted & Inspected
County health-dept approved
New Installs Only
Built right the first time
Free Estimates
No-obligation, on-site
Updated October 2, 2026
Your Colorado County septic installer
Across Colorado County's rural land, most homes run on their own on-site septic system instead of city sewer. We design, permit, and install new septic systems for new construction, manufactured, and mobile homes throughout the county — including Columbus, Eagle Lake, Weimar, Garwood, Alleyton, Sheridan — handling the soil and percolation testing and the county OSSF permitting from start to finish.
We install new septic systems across Colorado County, from Columbus and Alleyton out to Weimar, Glidden, and Sheridan, and down through the rice-prairie country around Eagle Lake, Garwood, Rock Island, Altair, and Nada. This is genuinely rural land along I-10 and the Colorado River — farms, ranchettes, and homesteads beyond the reach of any sewer line, while Columbus and Weimar run their own city sewer. A new house or manufactured home out here goes live on its own on-site septic system, and we size, permit, and install it start to finish.
What we install in Colorado County
Site Evaluation & Perc Testing
We evaluate your soil and run the percolation test that determines how well your ground absorbs water — the foundation of a system that works.
System Design & Sizing
We size the tank and drainfield to your home's bedroom count and your soil's absorption rate, then engineer a layout that fits your lot.
Permitting & County Approval
We prepare and submit your on-site sewage facility (OSF) permit application and coordinate approvals with your county health department.
Excavation & Site Prep
We prepare the site and excavate for the tank and drainfield with the right grade and setbacks — protecting your wells, structures, and property lines.
Tank Installation
We set the septic tank, connect the inlet and outlet plumbing at the correct grade, and install the effluent filter and risers for easy future access.
Drainfield Installation
We install the drainfield (leach field) that disperses treated effluent safely into the soil, sized to your percolation results and available area.
See how a full septic installation works
Comparing installers? See the best septic installers in Colorado County
We handle Colorado County permitting
On-site sewage facilities (OSSF) are permitted at the county level. We prepare the application, submit the soil and design documentation, and see it through approval and final inspection — so your Colorado County system is fully permitted and passes the county inspection.
In unincorporated Colorado County, septic permitting runs through the Colorado County Permit Office at 305 Radio Lane in Columbus; the county's program doesn't cover incorporated cities such as Columbus and Weimar. The county's published process starts with the landowner's application and fee, then a soil survey and site evaluation by a licensed site evaluator, registered sanitarian, or professional engineer. Non-standard systems — which includes the aerobic units most lots here end up needing — must be designed by a registered engineer or sanitarian, and the design and planning materials go to the Permit Office for approval before a Permit to Construct is issued to the installer. The system can't be covered before the final inspection, spray-dispersal aerobic systems carry the state-required two-year maintenance contract, and permits are valid for one year. We run the whole sequence for you.
Local OSSF permitting authority: Colorado County Permit Office
Typical county permit fee: About $250 (county fees change — we confirm the current amount during permitting)
New to septic? Our guides cover the basics: How Much Does It Cost to Install a Septic System in Texas? (2026) · What Size Septic Tank Do I Need? · What Is a Perc Test (and Why Does It Matter)?
Soil & site conditions in Colorado County
Colorado County straddles two soil worlds. The northern uplands around Columbus, Weimar, and Alleyton are Post Oak Savannah — fine sandy loams over slowly permeable clay subsoils — while the southern rice prairie around Eagle Lake, Garwood, and Nada sits on very slowly permeable loam-over-claypan ground. In both halves, water tends to perch on the clay after rain instead of soaking through, which is why many sites fail conventional-drainfield criteria and end up with an aerobic system with spray or drip dispersal. The on-site soil evaluation settles it for your tract.
What a new septic system costs in Colorado County
Our installed prices are flat by system type and cover the system and its installation. The soil evaluation (perc test), the engineered design, and the county permit are not included — we can handle them for you and quote them separately. The soil evaluation also decides which of the three systems your lot needs.
| System type | Installed price |
|---|---|
| Conventional gravity | $8,000 |
| Aerobic (ATU) + spray | $11,950 |
| Aerobic (ATU) + drip | $13,950 |
Colorado County's published single-family OSSF permit fee is $250, and it isn't included in the prices above. County fees change, so the current amount is confirmed when the permit is filed.
Cities & towns we serve in Colorado County
More Colorado County communities we install in
We checked each community the same way as our town pages: spots within 3 miles of the town center, run through the USDA soil survey and FEMA's flood maps. A map sample isn't your lot; the soil borings on your property decide the system.
| Community | Most common soils | Rated "very limited" for a drainfield | In a FEMA high-risk flood zone |
|---|---|---|---|
| Eagle Lake | Nada, Telf | 20 of 20 spots | 1 of 20 spots on land |
| Alleyton | Straber, Brazoria | 17 of 21 spots | 9 of 21 spots on land |
| Glidden | Straber, Nez | 20 of 20 spots | 4 of 20 spots on land |
| Altair | Udarents, Nada | 19 of 21 spots | 7 of 21 spots on land |
| Garwood | Dacosta, Norwood | 21 of 22 spots | 12 of 22 spots |
| Rock Island | Garwood, Nada | 22 of 22 spots | 3 of 22 spots |
| Sheridan | Cheetham, Tremona | 21 of 22 spots | 3 of 22 spots |
| Nada | Laewest, Dacosta | 20 of 22 spots | 6 of 22 spots |
| Oakland | Hallettsville, Carbengle | 21 of 22 spots | 5 of 22 spots |
| Frelsburg | Tremona, Hallettsville | 21 of 22 spots | 0 of 22 spots |
Sources: USDA NRCS Soil Survey (SSURGO) and FEMA National Flood Hazard Layer, checked October 2, 2026. Spots on open water (lakes, rivers, bays) are left out of the flood column, which covers land only. Check your own lot with the free land check.
We also install new septic systems across the rest of our service area: Harris County · Montgomery County · Fort Bend County · Waller County · Liberty County · Washington County · Grimes County · San Jacinto County · Walker County · Austin County · Wharton County · Brazoria County · Chambers County · Polk County.
Colorado County septic questions
Do I need a permit for a septic system in Colorado County?
Yes. A new on-site sewage facility (OSSF) requires a county permit plus a soil/site evaluation before installation. We handle the full permitting process for you, start to finish.
How much does a septic system cost in Colorado County?
It depends on your soil type, system type, and drainfield size. Use our instant estimator for a ballpark, then we confirm the exact price after a free on-site evaluation.
Do you install septic systems for manufactured and mobile homes?
Yes — manufactured and mobile homes on rural Colorado County land are what we install most. We size and permit the right system for your home and lot.
Who issues septic permits in Colorado County, and what does the permit cost?
The Colorado County Permit Office at 305 Radio Lane in Columbus, (979) 732-2435, issues OSSF permits for unincorporated land. The fee for a single-family residence is $250 on the county's adopted fee schedule, and it covers the application, permit, inspections, and notice of approval — the same fee whether the system is conventional, aerobic, or another type. We confirm the current figure when we file.
What's the permit process for a new septic system in Colorado County?
The landowner applies at the Permit Office and pays the fee, then a licensed site evaluator, registered sanitarian, or professional engineer does the soil survey and site evaluation. Non-standard systems — including aerobic units — must be designed by a registered engineer or sanitarian, and the design goes to the Permit Office for approval before a Permit to Construct is issued. The system can't be covered until it passes final inspection. We handle every step.
Why do so many Colorado County sites need an aerobic system?
Both halves of the county fight the same problem: water perching on clay. The northern Post Oak Savannah runs sandy loam over slowly permeable clay subsoil, and the southern rice prairie sits on claypan soils like the Nada series, where water stalls after every rain. Either way, many sites fail the TCEQ criteria for a conventional gravity drainfield, and an aerobic system with spray or drip dispersal is the design that passes.
Can you install a septic system for a manufactured or mobile home in Colorado County?
Yes. Manufactured homes on rural tracts around Columbus, Eagle Lake, Weimar, Garwood, and Sheridan need their own permitted on-site system, and the county process is the same as for a site-built house — application, soil survey and site evaluation, approved design, Permit to Construct, licensed installation, and final inspection before cover.
Does an aerobic system in Colorado County need a maintenance contract?
Yes — spray and surface-irrigation aerobic systems carry the state-required two-year maintenance contract from the start, per TCEQ 30 TAC Chapter 285. That contract is part of the permit packet, not an afterthought, so it has to be in place before the county approves the system. It's priced separately from the install, and we can help you line it up.
How long is a Colorado County septic permit good for?
Permits are valid for one year from issuance, so the install needs to happen inside that window. In practice that's not a problem — once the design is approved and the Permit to Construct is issued, we schedule the install and the final inspection well inside the year. If a project stalls, the permit can be renewed through the Permit Office.
Get your free Colorado County estimate
Tell us about your property and we'll size your system and schedule a free, no-obligation on-site evaluation.
Buying land in Colorado County? Check the soil before you close
Enter any address and get the USDA soil rating, FEMA flood zone, mapped wetlands, and the septic system type you're likely looking at — free, in about ten seconds.
Serving property owners across the region
Counties We Serve
- Harris County
- Montgomery County
- Fort Bend County
- Waller County
- Liberty County
- Washington County
- Grimes County
- San Jacinto County
- Walker County
- Colorado County
- Austin County
- Wharton County
- Brazoria County
- Chambers County
- Polk County
Don't see your county?
We're often able to serve nearby areas too. Reach out with your property's location and we'll let you know if we can help.
Request a Free Estimate