Mobile Home Septic Systems in Texas (2026 Guide)
Mobile homes in Texas follow the same TCEQ septic permit process as stick-built homes. A conventional system costs $8,000-$12,000 and aerobic runs $12,000-$20,000.
Mobile Home Septic Systems in Texas (2026 Guide)
Mobile homes in Texas follow the same TCEQ septic permit process as stick-built homes. A conventional system costs $8,000-$12,000 and aerobic runs $12,000-$20,000.
Whether you're placing a new manufactured home on rural land, moving a used mobile home onto a lot with an existing septic system, or living in a mobile home park, the rules for wastewater disposal come from TCEQ (Texas Commission on Environmental Quality) under 30 TAC Chapter 285. TCEQ issued 43,215 OSSF permits across Texas in 2024, with roughly 20% of new Texas homes relying on septic systems.
This guide covers the permit process, tank sizing, costs, and the key differences between private lot and mobile home park setups.
| Topic | Key Facts |
|---|---|
| Permit required? | Yes, same TCEQ permit as any home |
| Tank size (2-3 BR single-wide) | 750-1,000 gallons |
| Tank size (3-4 BR double-wide) | 1,000-1,250 gallons |
| Conventional system cost | $8,000-$12,000 |
| Aerobic system cost | $12,000-$20,000 |
| Who regulates the septic? | TCEQ (not HUD) |
| 10-acre exemption | May skip permit if lot is 10+ acres |
Do You Need a Septic Permit for a Mobile Home in Texas?
Yes. TCEQ requires a permit for any septic installation, repair, or connection for mobile homes, following the same 7-step process as any other home.
The permit process for a mobile home septic system follows these steps:
- Hire a licensed site evaluator to test your soil and assess the property
- Get a perc test to determine what type of system your soil supports
- Have the system designed by a licensed installer or engineer
- Submit the permit application to your county's TCEQ-authorized agent
- Receive Authorization to Construct after county review (typically 2 to 4 weeks)
- Install the system with a licensed installer, with county inspections at key stages
- Pass final inspection and receive your operating permit
The 10-acre exemption: Per TCEQ's permitting rules (30 TAC Chapter 285), if your property is 10 acres or more and the home is a single-family residence, you may qualify for a permit exemption. A TCEQ-licensed site evaluator must still conduct a site evaluation. Even exempt properties should get a professional assessment, since an improperly installed system on rural land can contaminate your well water.
What's different for mobile homes: Nothing, from TCEQ's perspective. According to TCEQ's OSSF program, the septic system permit process doesn't distinguish between manufactured homes and stick-built homes. However, some counties may have additional requirements for manufactured housing placement that affect where you can locate the septic system on the lot.
What Size Septic Tank Does a Mobile Home Need?
Septic tank sizing is based on bedroom count, not home type: 750 gallons for 1-2 bedrooms, 1,000 gallons for 3, and 1,250 gallons for 4.
| Bedrooms | Minimum Tank Size | Estimated Daily Flow |
|---|---|---|
| 1 - 2 | 750 gallons | 300 gallons/day |
| 3 | 1,000 gallons | 450 gallons/day |
| 4 | 1,250 gallons | 600 gallons/day |
Per TCEQ's minimum tank sizing rules (30 TAC 285.32), most single-wide mobile homes with 2 to 3 bedrooms need a 750 to 1,000 gallon tank. Double-wides typically have 3 to 4 bedrooms and need 1,000 to 1,250 gallon tanks.
Considerations specific to mobile homes:
- Water fixtures. Some mobile homes have smaller fixtures that use less water than standard homes. This doesn't change the minimum tank size (which is based on bedrooms), but it may mean your system handles the load more easily.
- Garbage disposals. If your mobile home has a garbage disposal, some evaluators recommend a larger tank because disposals increase the solid waste entering the system.
- Future replacement. If you might replace a single-wide with a double-wide someday, consider installing a larger tank now. It costs less during initial installation than upgrading later.
What Type of Septic System Works Best for a Mobile Home?
The same system types available for conventional homes work for mobile homes. Your soil conditions and lot size determine the best choice, not the home type.
| System Type | Best For | Approximate Cost | Annual Maintenance |
|---|---|---|---|
| Conventional (gravity) | Good soil, adequate lot size | $8,000 - $12,000 | $300 - $500 |
| Aerobic treatment unit | Poor soil, small lots | $12,000 - $20,000 | $600 - $1,200 |
| Mound system | Shallow bedrock, high water table | $12,000 - $25,000 | $400 - $800 |
| Drip irrigation | Very small lots, difficult soil | $15,000 - $30,000 | $500 - $1,000 |
For most mobile home installations on private lots with decent soil, a conventional system is the standard choice. According to Texas A&M AgriLife Extension's OSSF program, aerobic systems are more common in areas with heavy clay soil (much of Central Texas and the Blackland Prairie) or on smaller lots where there isn't room for a conventional drain field.
Does a Mobile Home Septic System Cost More Than a Stick-Built Home?
Septic costs are the same for mobile homes and stick-built homes, typically $8,000-$12,000 for a conventional system and $12,000-$20,000 for aerobic in Texas.
| Cost Category | Range |
|---|---|
| Site evaluation and perc test | $250 - $600 |
| Permit fees | $300 - $800 |
| Conventional system installation | $8,000 - $12,000 |
| Aerobic system installation | $12,000 - $20,000 |
| Plumbing connection (home to tank) | $500 - $2,000 |
Where costs might differ for mobile homes:
- Plumbing connection. Mobile homes sit on piers or blocks, which means the sewer line from the home to the tank may need different routing or support compared to a slab-on-grade home. This can add a few hundred dollars.
- Location on lot. Mobile homes are often placed on rural properties where the ideal septic location might be farther from the home than in a typical subdivision, requiring a longer sewer line and possibly a pump.
- Soil conditions. Rural properties where mobile homes are common may have better or worse soil than suburban lots. The perc test determines this, not the home type.
Who Regulates What: HUD vs. TCEQ?
HUD regulates how the mobile home itself is built. TCEQ regulates the septic system once the home is placed on a lot. They don't overlap.
| Jurisdiction | HUD | TCEQ |
|---|---|---|
| What they regulate | Home construction, electrical, plumbing inside the home | Septic system design, installation, permits, maintenance |
| Standards | HUD Code (federal) | 30 TAC Chapter 285 (state) |
| Inspections | Home manufacturing plant | Septic installation on-site |
| Your contact for issues | HUD or Texas DSHS | County authorized agent or TCEQ |
The plumbing inside your mobile home is built to HUD standards during manufacturing. The septic system outside the home, from the connection point under the house to the tank and drain field, is regulated by TCEQ.
The connection point is where the two jurisdictions meet. Your plumber or septic installer handles the transition from the home's plumbing stub-out to the sewer line running to the tank.
How Do Mobile Home Park and Private Lot Septic Systems Differ?
Mobile home parks typically use shared systems maintained by the park owner, while private lots require individual systems that the homeowner installs and maintains.
| Factor | Mobile Home Park | Private Lot |
|---|---|---|
| System type | Central treatment or individual tanks | Individual septic system |
| Who pays for installation | Park owner | Homeowner |
| Who maintains the system | Park owner | Homeowner |
| Minimum lot area | Park-specific (high density) | 15,000 sq ft minimum per TCEQ (20,000 with well) |
| Permit holder | Park owner | Homeowner |
| Connection type | 4-inch sewer riser per stand | Direct sewer line from home to tank |
If you live in a mobile home park:
- The park owner is responsible for the septic system (whether it's individual tanks or a central system)
- You typically can't choose your own septic provider
- If you notice septic problems (slow drains, odors), report them to park management
- The park must maintain systems according to TCEQ standards
If you own your lot:
- You're fully responsible for the septic system
- You choose the installer, pay for the system, and handle all maintenance
- The operating permit is in your name
- For aerobic systems, you sign the maintenance contract (required by TCEQ under 30 TAC Chapter 285)
Can You Connect a Used Mobile Home to an Existing Septic System?
Moving a used mobile home onto a lot with an existing septic system requires an inspection and usually a new TCEQ permit before you can connect.
Here's what to check:
- System capacity. Does the existing tank match the bedroom count of your mobile home? A 2-bedroom system can't serve a 4-bedroom home.
- System condition. Have a licensed inspector evaluate the tank, drain field, and all components. Systems that have been sitting unused may have deteriorated.
- Permit status. Check with your county to see if the existing system has a valid operating permit. An unpermitted system may need to be brought up to current code.
- Connection logistics. The sewer line from the home to the tank may need to be rerouted depending on where the mobile home sits relative to the tank.
- Setback compliance. Make sure the mobile home placement doesn't violate any setback distances between the home and the septic components.
Common issues with existing systems and used mobile homes:
- The previous home may have been smaller (fewer bedrooms), meaning the tank is undersized for your new home
- Old systems may use outdated designs that don't meet current code
- Drain fields on vacant properties can be damaged by vehicle traffic, tree root growth, or soil erosion during the time the lot sat empty
- If the previous system was aerobic, the maintenance contract will have lapsed, and the system may need service before activation
As Nathan Glavy, a program specialist with the Texas Water Resources Institute (part of Texas A&M AgriLife Extension), notes, "Inspecting and maintaining septic systems can help prevent negative impacts on local water quality and public health." This applies regardless of whether the home is manufactured or stick-built.
When in doubt, have a full septic inspection done before closing on the property or moving the home. An inspection costs $200 to $500 and can save you from discovering a failed system after you've already moved in.
Need a septic inspection or installation for your mobile home? Find septic companies in your area
Frequently Asked Questions
Do I need a different type of septic system for a mobile home?
No. Mobile homes use the same septic systems as conventional homes. The system type (conventional, aerobic, mound, or drip) depends on your soil conditions, lot size, and local regulations, not the home type. A 3-bedroom mobile home on the same lot as a 3-bedroom stick-built home would use the same septic system.
Can I connect my mobile home to an existing septic tank without a permit?
No, connecting a different home to an existing system is considered an alteration under 30 TAC Chapter 285 and requires a permit. The county needs to verify that the existing system is adequate for the new home's wastewater load. Even if the tank size matches, the connection work itself should be done by a licensed installer.
Is septic cheaper for a single-wide mobile home than a double-wide?
A single-wide typically saves $200-$500 on the tank itself, but total installation costs depend more on soil and system type. A single-wide with 2 bedrooms needs a 750-gallon tank, while a double-wide with 4 bedrooms needs a 1,250-gallon tank. The bigger cost factors are soil conditions, system type, and the distance from the home to the tank. Most of the installation cost is in the drain field, not the tank itself.
What happens if my mobile home park's septic system fails?
The park owner is responsible for all repairs and must maintain the system per TCEQ rules, or face fines up to $25,000 per day. If you notice signs of septic failure (sewage odors, wet areas, slow drains), report them to park management immediately. If the park owner doesn't address the issue, you can file a complaint with your county's TCEQ-authorized agent or directly with TCEQ.
Can I install a septic system myself for my mobile home?
No, Texas requires a licensed installer for all septic system construction, with fines up to $10,000 per violation for unpermitted work. The permit application requires a licensed installer's or designer's information, and county inspectors verify the work at multiple stages. The only exception is very basic maintenance like pumping, which doesn't require a license. Some counties (like Ector County) allow homeowner installation for primary residences, but this is uncommon and still requires a permit and inspections.
Last updated: February 7, 2026 Reviewed by: Texas Septic Guide Editorial Team, TCEQ regulatory research
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