Updated October 20, 2026
Short answer
From Quick Flow Septic, an aerobic septic system costs $11,950 installed with spray dispersal or $13,950 with drip dispersal, flat, anywhere in our 15 counties around Houston. A conventional system, where the soil allows one, is $8,000. The soil evaluation, the engineered design, the county permit, and the initial two-year maintenance contract are quoted separately, and an aerobic system has running costs a conventional one doesn't: electricity, upkeep, and the occasional wear part.
Aerobic septic system cost at a glance
We price aerobic installs by dispersal type, not job by job: $11,950 for an aerobic treatment unit (ATU) with spray dispersal and $13,950 for an ATU with drip dispersal, installed. Most installers around Houston don't publish installed prices, so a written quote is usually the first number a homeowner sees; ours is on the page. The table below puts both next to a conventional gravity system at $8,000, which is what you'd pay if the site evaluation shows your lot can take one.
What the installed price covers
The flat price covers the aerobic treatment unit and its tanks (the treatment tank where solids settle and the aerator works, and the pump tank that holds the treated effluent), the control panel and its alarm, the spray heads or the buried drip field, and the installation itself: the complete system in the ground and working.
What's quoted separately
Four things sit outside the installed price, and we quote them by phone for your lot before any work starts. The site evaluation, with the soil borings Chapter 285 requires, done by a licensed site evaluator or engineer (§285.30). The system design, which for an aerobic system is sealed by a professional engineer or a registered sanitarian. The county permit and its fee, which each county sets; Austin County, for example, charges $375 for an aerobic permit against $275 for a conventional one. And the initial two-year maintenance contract every new aerobic system needs before the county approves it for use. Unusually hard site access, such as heavy clearing or rock, is priced separately too.
Spray or drip: why drip costs $2,000 more
Both are aerobic systems; the difference is how the treated water goes back into the ground. Spray dispersal uses pop-up heads to spread the effluent over a set area of lawn, usually at night, and it needs open yard with enough setback from the house, the property line, and any well. Drip dispersal sends the water through small tubing buried just below the surface. It is invisible and fits tighter, sloped, or irregular lots, but it takes more tubing and filtration, which is why it costs $2,000 more. Your site evaluation, lot size, and setbacks decide which one the design calls for.
Why an aerobic system costs more than a conventional one
An aerobic system is a small treatment plant: an aerator, a pump, a control panel, and a disinfection step on top of the tanks and the dispersal field. That's why it runs $3,950 to $5,950 more than a conventional system. It is rarely a free choice, though. A conventional drainfield needs soil that can absorb and filter the effluent on its own, and much of the clay around Houston fails that test in the site evaluation. An aerobic system treats the water well enough to disperse it on soil a conventional field can't use, so on many lots it is the only system the county will permit.
How home size affects an aerobic system
Bedrooms and square footage set the design flow under Table III, and Table II sets the minimum capacity of the aerobic unit; whichever of bedrooms or square footage gives the bigger number decides. The table below shows both, computed with the same TCEQ sizing our instant estimate uses. Our price stays flat by dispersal type: a bigger home changes the size of the unit and the field, not the installed price.
What it costs to own an aerobic system
Plan for running costs a conventional system doesn't have. Electricity: the aerator runs continuously and the pump cycles to dose the field. Maintenance: a new system has to be covered by a two-year maintenance contract; after that, Texas lets the owner of a single-family home either keep a contract or maintain the system personally (30 TAC §285.7), although a county can require a contract if a violation isn't fixed, and some county orders are stricter, so check yours. Disinfection: the effluent is disinfected before it's dispersed, and that supply gets topped up. Wear parts: the aerator and the pump are serviced and occasionally replaced. The tanks are pumped when solids build up, which depends on how many people live in the house.
How long it takes
Once the site evaluation and the design are done, the county has 30 days to approve or deny a complete permit application (§285.3(c)), and the authorization to construct it issues is good for one year. The field work on a typical aerobic install takes a few days. The installer notifies the county at least five working days before the system is ready for inspection, and the system isn't covered until the county inspects it.
How to get your exact price
Start with the free land pre-check: it reads the soil survey, the flood maps, and the wetlands data for your address and tells you whether the lot is likely to need an aerobic system. Our instant estimate gives you a planning range in a minute. The firm, lot-specific answer comes from the on-site site evaluation, which is also what the design and the permit are built on, so it pays to book it early. Call or text us and we'll quote the evaluation, the design, and the permit for your lot.
Free tool
Will your lot need an aerobic system? Check the address.
USDA soil rating, FEMA flood zone, and mapped wetlands for any Texas address — plus the system type and flat price you're likely looking at. About ten seconds, no account.
Aerobic septic system cost by type (installed)
| System | Installed price | Usually fits |
|---|---|---|
| Aerobic (ATU) + spray | $11,950 | Clay-heavy lots with open lawn and room for setbacks |
| Aerobic (ATU) + drip | $13,950 | Tight clay, smaller, sloped, or irregular lots |
| Conventional gravity (for comparison) | $8,000 | Well-draining soil with room for a standard drainfield |
Aerobic unit size by home (TCEQ Tables II and III)
| Home | Design flow (Table III) | Minimum tank (§285.91) | Minimum aerobic unit (Table II) |
|---|---|---|---|
| 1-bedroom home | 180 GPD | 750 gal | 360 GPD |
| 2-bedroom home | 180 GPD | 750 gal | 360 GPD |
| 3-bedroom home | 240 GPD | 750 gal | 360 GPD |
| 4-bedroom home | 300 GPD | 1,000 gal | 480 GPD |
| 5-bedroom home | 360 GPD | 1,250 gal | 600 GPD |
| 6-bedroom home | 420 GPD | 1,250 gal | 720 GPD |
County permit fees (billed by the county, not part of the installed price)
| County | County permit fee |
|---|---|
| Harris | $223 |
| Montgomery | $350–$480 |
| Fort Bend | $575 |
| Waller | $310 |
| Liberty | $275 |
| Washington | $325 |
| Grimes | $420 |
| San Jacinto | $310 |
| Walker | $210 |
| Colorado | $250 |
| Austin | $275–$375 |
| Wharton | Set at application |
| Brazoria | $250 |
| Chambers | $245 |
| Polk | $300 |
Frequently asked questions
How much does an aerobic septic system cost in Texas?
$11,950 installed with spray dispersal or $13,950 with drip from Quick Flow Septic, flat by dispersal type in our 15 counties around Houston. The site evaluation, the design, the county permit, and the two-year maintenance contract are quoted separately.
How much does an aerobic septic system cost for a 3- or 4-bedroom house?
The same flat price: $11,950 with spray or $13,950 with drip. Size changes the unit, not our price. Under Table II, a home with up to three bedrooms and up to 2,500 sq ft needs an aerobic unit rated for at least 360 gallons per day; a four-bedroom home needs at least 480.
Why does drip cost more than spray?
Drip uses a grid of buried tubing plus extra filtration instead of a set of spray heads, so there is more material and more work in the ground. With us it costs $2,000 more ($13,950 against $11,950), and it is the better fit on tight, sloped, or irregular lots and where spray setbacks don't fit.
Why is an aerobic system more expensive than a conventional one?
It has more parts (an aerator, a pump, a control panel, and a disinfection step) and it does more work: it treats the wastewater well enough to disperse it on soil a conventional drainfield can't use. With us the difference is $3,950 with spray or $5,950 with drip over an $8,000 conventional system.
Does the price include the permit, the design, and the soil test?
No. The installed price covers the system and its installation. The site evaluation, the engineered design, the county permit and its fee, and the two-year maintenance contract are quoted separately; we price them by phone for your lot before any work starts.
Is a maintenance contract required for an aerobic septic system in Texas?
For the first two years, yes: a new aerobic system has to be covered by a maintenance contract before the county approves it for use. After that, the owner of a single-family home can keep a contract or maintain the system personally (30 TAC §285.7). A county can require a contract if a violation isn't fixed, and some county orders are stricter than the state rule, so check with yours.
What does an aerobic septic system cost to run each year?
It depends on the house, so we don't publish a single number. The running costs are electricity for the aerator and the pump, a maintenance contract or your own upkeep after the first two years, disinfection supplies, pumping when the solids build up, and the occasional aerator or pump replacement. We quote the maintenance contract by phone.
How long does an aerobic septic system last?
With proper installation and upkeep, the tanks and the dispersal field can last for decades. The aerator and the pump are wear parts that get serviced and occasionally replaced over the years. Keeping up the maintenance, protecting the field from traffic and paving, and watching what goes down the drain all extend the system's life.
Can I put in a conventional system instead to save money?
Only if the site evaluation shows your soil qualifies for a conventional drainfield and the lot has room for one; if it doesn't, the county won't permit it. Our free land pre-check gives you an early read on which way your lot is likely to go.
Quick Flow Septic installs new septic systems across 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.
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