Septic System Installation in Katy, Texas
Licensed, bonded septic installers in Katy and across Harris County. We handle the soil test, the county permit, and the full install.
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
Instant Estimate
Your Katy septic estimate in 60 seconds
A few quick questions and you'll see your system size and a price range. No obligation, no contact info to start.
What are you installing a septic system for?
We specialize in new installs for homes on rural land.
Katy & Harris County
New construction, manufactured & mobile homes
Out around Katy, homes beyond the reach of city sewer run on their own septic system. We install new systems for new builds, manufactured homes, and mobile homes. We run the soil and perc testing, pull the Harris County permit, and build it to pass inspection the first time.
Get My Free EstimateKaty grew up around the townsite platted after the Katy Line railroad arrived in 1895, and it's a city in three counties: Harris, Fort Bend and Waller. Homes in the city connect to city sewer; who permits a septic system around Katy depends on which county the land is in.
Septic systems in Katy
Katy's state historical marker tells how it grew from Cane Island, a stagecoach stop, into a townsite platted after the Missouri, Kansas & Texas Railroad, the "Katy Line", reached it in 1895; William Eule's 1897 rice crop started the area's big industry, and the city incorporated in 1945. Katy lies in Harris, Fort Bend and Waller counties, so the septic permit around it comes from whichever county the land is in: Harris County's Office of the County Engineer for unincorporated Harris County to the north and east, Fort Bend County Environmental Health for unincorporated Fort Bend to the south ($575 for a single-family home), and Waller County Environmental to the west and northwest ($310). Inside the city, the code lets the city compel owners to connect once a sanitary sewer has been laid within 150 feet of the property and city water is available, and failing to connect within 30 days of notice is a misdemeanor (Secs. 13.04.016–.017). Every home in a new city subdivision must connect to the central sewer (Sec. 10.05.005). Keep in mind that a Katy mailing address reaches well beyond the city: Cinco Ranch, for one, is unincorporated Fort Bend County.
Septic conditions around Katy
We ran 35 spots within 5 miles of downtown Katy through the same public data our free land check uses: the USDA soil survey, FEMA's flood maps and the National Wetlands Inventory. Here is what they show for a new septic system.
100%
35 of 35 spots
Soil the USDA rates "very limited" for a standard septic drainfield
100%
35 of 35 spots
Point to an aerobic system instead of a conventional drainfield
3%
1 of 35 spots
Inside a FEMA high-risk flood zone (the 100-year floodplain)
9%
3 of 35 spots
A mapped wetland within about 100 feet
Most of the ground around Katy won't take a standard gravity drainfield: water moves through the soil too slowly and water ponds on it after rain. Plan on an aerobic system with spray or drip dispersal, from $11,950 installed. The two soil borings on your own lot make the final call. Prices cover the system and installation; the site evaluation, design and county permit are quoted separately.
1 of the 35 spots is in a FEMA high-risk flood zone. A lot there adds floodplain rules to the septic design and usually a county floodplain permit, so check your lot's zone early.
Most common soils around Katy
| Soil | Spots | Drainfield rating | Main limitation |
|---|---|---|---|
| KatyKaty-Urban land complex, 0 to 1 percent slopes | 26 | Very limited | Slow drainage |
| CyfairCyfair-Katy complex, 0 to 1 percent slopes | 6 | Very limited | High water table, Slow drainage |
| EdnaEdna loam, 0 to 1 percent slopes | 2 | Very limited | High water table, Slow drainage |
| ClodineClodine-Urban land complex, 0 to 1 percent slopes | 1 | Very limited | High water table, Slow drainage |
A map sample isn't your lot. The USDA soil survey maps the landscape at 1:24,000, and Texas requires a licensed site evaluator or engineer to evaluate every tract before a permit (30 TAC §285.30). Run your own address through the free land check to see what the maps show for your lot.
Check my land freeSources: USDA NRCS Soil Survey (SSURGO), FEMA National Flood Hazard Layer, USFWS National Wetlands Inventory. 35 spots on a 1.6-mile grid, checked October 2, 2026.
What we install in Katy
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.
Built for Harris County soils
Advanced aerobic treatment systems
The USDA soil survey rates most of the ground around Katy "very limited" for a standard drainfield: it drains too slowly, holds a high water table part of the year, or both. On lots like that a standard gravity drainfield won't pass, so you'll need an aerobic system with drip or spray dispersal. We don't guess at it — the on-site soil test tells us exactly what your lot can take.
We handle Harris County permitting for Katy
Septic permits around Katy are issued locally, usually by Harris County. We put the application together, turn in the soil and design paperwork, and stay on it through approval and the final inspection — so you're not the one chasing the permit office.
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)?
Local OSSF permitting authority: Harris County Office of the County Engineer — Wastewater Quality Permitting
Typical county permit fee: About $223 (county fees change — we confirm the current amount during permitting)
Permit steps, fees and FAQs for Harris CountyWhy Katy homeowners choose us
Licensed & Bonded
Move forward knowing your project is handled by a licensed, bonded installer.
New Construction & Mobile Home Specialists
We install new systems for new construction, manufactured, and mobile homes — so we're fast, precise, and up to date on the rules.
We Handle the Permits
Soil testing, design documentation, and county OSF approval — all managed for you.
Honest, Upfront Estimates
Clear, itemized quotes after we evaluate your site. No pressure, no surprises.
Local & Dependable
We know your county's requirements and show up when we say we will.
Built to Last
Properly sized, properly installed, and restored clean — a system you can forget about.
How your Katy install works
Instant estimate
Get a ballpark price for your Katy project online in about a minute.
Free on-site evaluation
We test your soil and confirm the right system for your lot.
Permit & design
We handle the Harris County OSSF permit end to end.
Install & inspection
Professional installation and final county sign-off.
What homeowners say
"Quick flow septic was a great experience!! Honest, good prices, and quick to respond to customer’s questions and concerns. Alex and his team will do everything to make it right. Would definitely recommend. 10/10"
"They handled our soil test, permit, and full septic install for our new build. The process was clear, the crew stayed on schedule, and the county inspection passed the first time."
The Ramirez Family
Montgomery County, TX
"We needed septic for our manufactured home and they took care of everything from design to approval. Clear pricing, good communication, and no surprises."
Carlos & Elena Martinez
Waller County, TX
"Our property was raw land and we did not know where to start. They sized the system, handled the county paperwork, and kept the project moving."
The Johnson Family
Liberty County, TX
"Responsive, professional, and familiar with the local requirements. They made the permit and installation process much easier than we expected."
Miguel Hernandez
Fort Bend County, TX
Katy septic questions
Who issues septic permits around Katy?
It depends on the county. On unincorporated land in Harris County, north and east of town, it's the Harris County Office of the County Engineer. In unincorporated Fort Bend County, to the south, it's Fort Bend County Environmental Health, at $575 for a single-family home. In Waller County, to the west and northwest, it's Waller County Environmental, at $310. We confirm the county and the city limits for your parcel first.
Does a Katy address mean the lot is in the City of Katy?
No. Katy mailing addresses reach far outside the city limits. Cinco Ranch, for example, has Katy addresses but is unincorporated Fort Bend County, outside the city and its sewer. The city's own GIS also maps 13 utility districts in and around Katy, so we check city limits and district boundaries before we design.
Do I have to connect to Katy's city sewer?
Inside the city, once a sanitary sewer has been laid within 150 feet of your property and city water is available, the city can require the connection, and not connecting within 30 days of notice is a misdemeanor (Secs. 13.04.016–.017). In a new subdivision in the city, every home must connect to the central sewer system.
Will I need an aerobic septic system in Katy?
Probably. Of the 35 spots we checked within 5 miles of downtown Katy, 35 point to an aerobic system, mainly because water moves through the soil too slowly and water ponds on it after rain. Aerobic systems start at $11,950 installed (the site evaluation, design and permit are quoted separately). The two soil borings on your lot make the final call.
Is Katy in a flood zone?
Parts of the area are. 1 of the 35 spots we checked within 5 miles of downtown Katy is inside a FEMA Special Flood Hazard Area (the 100-year floodplain), including 1 in the regulatory floodway. Your own lot's zone is what counts, so run the address through our free land check before you buy or design.
Do you install septic systems in Katy?
Yes. We install new septic systems on land in and around Katy and across Harris County — for new construction, manufactured homes, and mobile homes. Inside city limits that have city sewer, you'll usually connect to the sewer instead.
How much does a septic system cost in Katy?
Most Katy installs run between $8,000 and $13,950 — $8,000 for a conventional system where the soil allows it, $11,950 for an aerobic spray system, and $13,950 for an aerobic system with drip dispersal. The soil evaluation (perc test), the engineered design, and the county permit are quoted separately. Run the instant estimate for a ballpark, and we'll confirm the exact number once we've seen the lot.
Do I need a permit for a septic system in Katy?
Yes. Every new septic system needs a permit and a soil evaluation before anyone digs. Around Katy the permit usually comes from Harris County, and we take care of all of it for you.
Check your Katy lot before you buy or build
Soil rating, flood zone, wetlands, and the likely septic system type for any Katy address — free, in seconds.
Get your free Katy septic estimate
Tell us a little about your Katy property and we'll size your system and set up a free visit. No pressure, no obligation.