Quick Answer: Before buying a Johnson County home with a septic system, verify the system type, location, permit or lawful exemption status, approved capacity, service history, and current operation. Arrange an appropriate septic evaluation during your contractual due-diligence period, investigate signs of failure, and confirm the ongoing maintenance obligations—especially for aerobic systems. Johnson County Development Services handles on-site sewage facility permits in its jurisdiction, while Texas Commission on Environmental Quality rules provide the statewide framework. A regular home inspection alone may not answer whether the wastewater system is suitable for your plans. [1][2][3]

By Jason Cech, Broker Associate | Texan Heritage Realty Group, Fathom Realty

Updated October 19, 2026

Why is a septic system different from city sewer service?

A home connected to a public sewer sends wastewater into a utility-operated network. A home with an on-site sewage facility—usually called an OSSF or septic system—treats and disposes of wastewater on or near the property. That means the owner is responsible for the system's condition, maintenance, and, when needed, repair or replacement.

This matters for buyers looking outside city limits near Cleburne, Joshua, Godley, Alvarado, Grandview, and rural Johnson County. Two homes with similar square footage and acreage can have very different wastewater systems and future ownership obligations. You should know which one you're buying before the option period ends.

What type of septic system does the property have?

Start by asking the seller for the system's design or permit records and the identity of the components on the ground.

Texas Commission on Environmental Quality (TCEQ) explains that treatment and disposal selection depends on site conditions and that ongoing maintenance is part of the total cost. Do not assume an aerobic system is defective because it has an alarm or service contract; those may be normal system features. The concern is whether the system works properly and is maintained as required. [2][3]

Where do I find septic permits and approved plans in Johnson County?

For property in Johnson County's OSSF permitting jurisdiction, start with Johnson County Development Services. The county says its office issues OSSF permits, reviews applications and plans, and performs related inspections. It also provides septic-system applications and local OSSF rules. For a property inside a municipality or another permitting jurisdiction, confirm the correct authority rather than assuming the county office has every record. [1]

Ask for the approved plan, installation permit or authorization, final inspection or approval documentation if available, and any later modification or repair records. Those records can help identify the system's original design, disposal area, and approved wastewater load. They do not, by themselves, prove the system is working today.

Does a septic system without a permit automatically mean the property is illegal?

No. TCEQ describes limited exceptions, including certain grandfathered systems and a narrowly defined exemption sometimes called the 10-acre rule. That rule has multiple conditions; owning ten acres alone is not enough. A buyer should ask the actual permitting authority whether an exemption applies to this particular system. TCEQ also says local programs can impose requirements more stringent than statewide minimums. [4]

A seller's statement that “it's always worked fine” is useful background, not a substitute for records or an evaluation.

Should I get a separate septic inspection before buying?

Usually, a system-specific evaluation is prudent, particularly if records are incomplete, the property is older, the home has been vacant, or the buyer plans additional occupants or structures. A general TREC home inspection may not establish tank integrity, drainfield performance, pump condition, or design capacity.

TCEQ states that a separate OSSF evaluation is not universally required or regulated by TCEQ simply because a home is being sold, although a mortgage company may require one. That means the decision should be based on the property, lender, contract, and the buyer's risk—not a made-up statewide “septic inspection required for every sale” rule. [2]

Arrange a qualified OSSF professional familiar with the system type and confirm credentials, scope, access requirements, and any testing limitations before scheduling. Ask what will actually be evaluated and whether the professional can review the county records.

What are the warning signs of a failing septic system?

Possible warning signs include persistent sewage odors, wastewater backing up, unusually slow drains, surfacing effluent, saturated or unusually lush areas over the disposal field, alarms that are not operating correctly, or repeated pump or component failures. These are reasons to investigate, not a diagnosis by themselves. Wet soil after a heavy rain, for example, may have several explanations.

TCEQ identifies hydraulic overloading, unsuitable site or soil conditions, organic overloading, poor maintenance, and age as possible contributors to system problems. A specialist should determine the actual cause. [2]

Should the seller pump the tank before the evaluation?

Do not order pumping reflexively without discussing timing with the septic evaluator. The professional may need to observe the system under normal operating conditions and may recommend a particular inspection or pumping sequence. Ask for past pumping records and whether the tank needs service based on its condition and use. TCEQ describes three to five years as a general pumping recommendation for conventional systems, not a mandatory schedule for every household and every system. [3]

What records should I ask the seller to provide?

  • Original OSSF permit or documentation of the claimed lawful exemption.

  • Approved design, site plan, and location of tank, treatment components, and disposal field.

  • Installation date and information about additions or major repairs.

  • Pumping receipts and maintenance history.

  • Aerobic-system service contract, inspection reports, alarm or pump records, and warranty information, when applicable.

  • Any notices of violation, prior complaints, or known malfunctions.

  • Information about previous backups, sewage surfacing, or replacement work.

  • A current evaluation report and estimates for significant deficiencies when appropriate.

The TREC Seller's Disclosure Notice should also be reviewed when applicable, but it is not a warranty or a substitute for due diligence. Disclosure duties and exemptions depend on the transaction.

How much ongoing maintenance should I budget for?

There is no honest single dollar amount that applies to every Johnson County septic system. Maintenance costs depend on system design, usage, equipment age, service-provider pricing, and applicable local requirements. Ask a provider for a property-specific written quote rather than relying on an online average.

TCEQ says aerobic or other covered treatment systems may have maintenance-contract and reporting requirements. Its guidance describes reports generally at least every four months, with some qualifying monitored systems eligible for a six-month interval; limited homeowner-maintenance options may exist after the initial period, subject to local requirements. Verify the exact rule for the system you're buying. [3]

Can I add a guest house, workshop bathroom, or second home later?

Maybe—but don't assume the existing system can serve additional plumbing. The approved design is tied to site conditions and expected wastewater use. Adding bedrooms, bathrooms, a second dwelling, or a shop with plumbing may require evaluation, redesign, permits, or an additional system. TCEQ says new installation, alterations, extensions, and many repairs generally require permitting, subject to specific exceptions. [4]

Also, don't place a driveway, barn, concrete pad, or workshop over a septic tank or disposal field without qualified review. TCEQ explicitly warns owners against building or driving over system components. [2]

This is especially relevant to buyers searching for acreage in Godley, Joshua, and Grandview. A five-acre property may have plenty of open land but still have limitations based on soil, setbacks, easements, and the location of the wastewater disposal area.

How do I negotiate a septic problem discovered during the option period?

First, get the right diagnosis. If a qualified evaluator finds a material deficiency, request a written explanation and, when possible, a scope and estimate. Then consider whether a seller-completed repair, a price change, or a lender-permitted seller contribution is appropriate. The solution must also satisfy the lender's property-condition requirements.

For a residential resale using current TREC Form 20-19, the signed contract governs the inspection and termination timeline; agreed repairs should be documented with the appropriate written amendment. Under the form's repair-completion provisions, agreed work generally must be completed before closing unless otherwise agreed, with required permits and qualified tradespeople. Farm and ranch or unimproved-land transactions may use different forms and need property-specific advice. [5][6]

Don't wait until the final day of the option period to discover that the entire disposal field may need replacement. The time to get answers is before your ability to make a decision under the contract expires.

What should I do after closing if the home has septic?

TCEQ advises new buyers to notify the local permitting authority that they are the new OSSF owner and ask about the proper startup procedures. Obtain the maintenance records, learn the alarm and service requirements, locate the system before landscaping or construction, and keep a file of permits and service receipts. [2]

What should acreage buyers avoid?

Don't assume “septic” means a single system type, that a large lot guarantees room for a replacement field, or that the seller's permit proves current performance. Don't confuse a routine tank pumping with a full evaluation. And don't buy a property intending to build a second home without confirming wastewater feasibility for that use.

Looking at a rural home near Cleburne, Joshua, or Godley?

Before you make an offer, contact Texan Heritage Realty Group. We can help build an acreage due-diligence checklist around the specific property, coordinate with qualified septic professionals and the correct permitting authority, and identify issues to resolve before closing. You can also browse North Texas homes and land.

Frequently Asked Questions

Is a septic inspection required to sell a home in Texas?

Not automatically by TCEQ for every resale. A lender may require an evaluation, and a buyer may choose to arrange one. Check the transaction and applicable local requirements. [2]

Who handles septic permits in unincorporated Johnson County?

Johnson County Development Services says it issues OSSF permits and handles related review and inspections in its jurisdiction. Verify the specific property's permitting authority. [1]

Can I buy a house with an older septic system?

Possibly. Age is only one factor. Evaluate the system's actual condition, maintenance history, design, repair needs, and suitability for the home's use.

Is an aerobic septic system more expensive to maintain?

It may involve more mechanical components, periodic inspections, and contract requirements than a simple conventional system. Get a system-specific service quote and verify local requirements. [3]

Does a ten-acre property automatically qualify for a septic permit exemption?

No. TCEQ's narrow 10-acre exception has several additional conditions, and the local authority should confirm applicability. [4]

Can I build a shop over my septic drainfield?

Do not assume you can. TCEQ warns against constructing improvements or driving over system components. Have the site plan reviewed before placing a building or driveway. [2]

Can a seller credit pay for a septic replacement after closing?

An allowable seller contribution may reduce eligible closing expenses, but it is not unrestricted repair cash. Financing and property-condition requirements may prevent closing with an unresolved deficiency. Confirm any proposal with the lender and title company. [5]

What if the septic system is working but there are no records?

Ask the permitting authority what records exist, clarify whether a lawful exemption may apply, and consider an evaluation. Missing records are a due-diligence issue, not automatic proof of failure.

Ready to buy acreage with your eyes open?

The land, the house, and the systems serving them all matter. Texan Heritage Realty Group, affiliated with Fathom Realty, helps buyers throughout Johnson County and North Texas understand what they're purchasing before they sign the final paperwork. Integrity. Tradition. Excellence.

About Jason Cech

Jason Cech is the Owner and Broker Associate of Texan Heritage Realty Group at Fathom Realty. Licensed since 2017, he has participated personally in more than 550 transactions, including acreage, land, and farm and ranch real estate. The team serves Cleburne, Joshua, Godley, Burleson, Alvarado, Grandview, and surrounding North Texas communities. [7]

Disclaimer: Texan Heritage Realty Group is affiliated with Fathom Realty. This article provides general real estate information, not legal, septic-system design, engineering, environmental, lending, tax, or inspection advice. Septic requirements vary by system, jurisdiction, and intended use. Consult the applicable permitting authority, TCEQ, qualified OSSF professionals, and a Texas real estate attorney when appropriate. TREC does not endorse individual license holders. Equal Housing Opportunity.