Travis County Septic Permit Guide: Process, Documents and Tips

Part of Travis County looks like the city, and part looks like ranch country. Drive west on SH 71 or RR 620 and you pass subdivisions on sewer, then a few miles later you reach acreage on septic. That mix is why many owners are unsure who to call when they need a septic permit.

This Travis County septic permit guide explains who issues permits, how the process works for a typical residential system, what documents to prepare and which questions to ask before you hire anyone. It draws on information published by Travis County and the Texas Commission on Environmental Quality (TCEQ). Procedures and fees change, so confirm current details with the county.

Who issues septic permits in Travis County

TCEQ sets the statewide rules for on-site sewage facilities (OSSFs) in 30 TAC Chapter 285. Local governments that act as authorized agents run the permit programs.

In unincorporated Travis County, that is the Travis County Transportation and Natural Resources department, or TNR. Its development services group reviews applications and inspects the work.

The county’s permit instructions begin with a simple question: is your property outside the city limits? The county website notes that it handles development outside corporate city limits. If your address is inside the City of Austin or another incorporated city, a different office applies. The City of Austin handles septic inside its own jurisdiction. Some cities also have their own arrangements or sewer service, so check before you start.

A good first step is to confirm your jurisdiction. Call TNR, check the county’s address lookup or ask your title company or surveyor. Owners in Bee Cave, Lakeway and Southwest Austin often find that two parcels on the same road fall under different authorities.

When you need a permit

You generally need a permit to build a new on-site sewage facility, to replace a system and to alter an existing one. The county confirms that damaged or replacement septic systems require an OSSF permit. If you are not sure whether a repair triggers a permit, ask TNR before work starts. A licensed professional can also help you decide. Our septic system repair page describes common repairs that may or may not need approval.

Routine pumping and basic maintenance do not require a permit.

Before you apply: check sewer availability

Travis County asks applicants for the distance from the property to the nearest sewer. This matters because rules can limit septic where sewer is close and available. The county’s instructions list distance to sewer among the information to gather.

If you live in a growing area, it is worth asking whether a sewer extension is planned. A septic permit does not always protect you from future requirements, and local utilities have their own rules. Ask your designer to look into it.

Information and documents to gather

According to the county’s residential OSSF page, you should collect:

The property address
The legal description from the Travis Central Appraisal District (TCAD)
The type of development (new home, addition or replacement)
The distance to the nearest sewer
A site plan
An OSSF checklist
A soil evaluation form
A floor plan
A maintenance contract, where maintenance is required

After inspection, the designer provides a certification letter.

For commercial projects, the county asks for more. The plot plan must show property lines, buildings, wells and OSSFs within 150 feet, floodplain status and the proposed location of sewage components. An erosion and sediment control plan is also required. Commercial and multi-unit properties follow a separate permit path, so ask TNR which one applies to you.

Gather everything before you apply. Missing items cause delays.

Working with a designer and installer

Most Travis County applicants hire a licensed professional to evaluate the site and prepare the design. They dig test pits, describe the soil, measure slopes and setbacks and decide what system the site can support. The soil evaluation form comes from this work.

Western Travis County has the kind of ground that demands careful design. Limestone close to the surface, caliche layers and clay pockets are common on lots near Lake Travis, Barton Creek and the Hill Country edge. Steep slopes add complications. Our post on septic systems in limestone and caliche soil explains how those conditions shape what is allowed.

A licensed installer builds the system. Ask both professionals for their license numbers and verify them with TCEQ or the county. For aerobic systems, a licensed maintenance provider also holds the contract.

The application process

Travis County lists a step-by-step process on its website. In broad terms:

Verify your address. Confirm the property lies outside incorporated city limits.
Gather the required information and documents. Use the list above.
Create or log in to the county’s online permitting platform. You select the On-Site Wastewater (Residential) permit type.
Upload documents and pay fees. Fee amounts appear in the county’s current fee schedule. We do not quote them here because they change and sources differ.
Wait for review. County staff review the application. The county can pause review until you answer comments.
Receive approval to build. Once approved, your installer can begin work.
Schedule inspections. Inspections are requested through the online system. The county notes that requests must be filed before 2 p.m. on the previous working day.
Complete the final inspection. The designer submits a certification letter after the work is checked.
Receive the final documentation. Keep it with your records.

Do not begin construction until the county says you may. Work done without approval can be ordered redone.

Reviews, comments and delays

Reviews often come back with comments. A reviewer might ask for a revised setback to a well, a corrected floor plan, a clearer site plan or a detail on the soil evaluation. Reply promptly and completely. The county can hold the review until it hears from you, so a slow response adds time.

Common reasons for delays include missing signatures, mismatched bedroom counts between the floor plan and the design, unclear legal descriptions and setbacks that do not work on the lot. Your designer can often prevent these problems by checking the package before filing.

Aerobic systems and maintenance contracts

Many western Travis County lots end up with aerobic treatment units because of shallow rock and tough soils. In Texas, aerobic systems require a maintenance contract with a licensed maintenance provider. TCEQ says the provider must test the system and report to the owner and permitting authority at least every four months, or every six months where the system has electronic monitoring that alerts the provider to failures.

Travis County’s application materials call for a maintenance contract where maintenance is required. Ask TNR about any county-specific terms, including how long an initial contract must run and when homeowners may maintain their own systems. TCEQ notes that local authorities can be stricter than the state minimum. Our guide to Texas aerobic septic maintenance contract rules covers the statewide basics.

Special conditions in Travis County

Certain parts of the county carry extra constraints.

Edwards Aquifer recharge and contributing zones. Parts of southwest Travis County are over or draining toward the Edwards Aquifer. On the recharge zone, state rules require at least one acre for each lot using an on-site system and a 150-foot setback from recharge features. Your designer must check the map for your parcel.

Floodplains and creeks. Properties near Barton Creek and other waterways may have floodplain limits. Setbacks apply to creeks, drainage ways and slopes.

Lakes and shorelines. Land near Lake Travis may face additional controls. Ask your designer to check.

Lot size. An older county document mentions a one-acre minimum from rules adopted years ago. That is dated, so verify the current lot size and density rules with TNR before you rely on them.

Disaster assistance. After the July 2025 flood, the county approved a waiver of development and septic permit fees for affected residents who submit a waiver request with their application. Check with TNR to see whether that program is still available for your situation.

Fees and budgeting

Permit fees are set by the county and may differ for residential and commercial projects. Published figures differ and some are undated, so the safest approach is to check the county’s published fee schedule or call TNR. Other costs include the designer, soil evaluation, installer, tanks and equipment, electrical work and the maintenance contract. Total costs vary widely by site. Our septic system installation page explains what goes into a project.

Sale and transfer

If you are buying or selling in Travis County, request the permit file and any maintenance records. Ask the county what it has on file for the address and whether any affidavits are recorded with the deed. If the home has an aerobic system, ask for service reports. Our post on buying a home with septic in the Hill Country offers a full checklist.

Common mistakes

Assuming the City of Austin or a nearby city handles your address
Hiring a contractor before getting a soil evaluation
Starting construction before approval
Not checking distance to sewer
Submitting a floor plan that does not match the design
Forgetting the maintenance contract for an aerobic system
Missing the 2 p.m. cutoff for inspection requests
Filing the wrong permit type

Who to call

For permit questions, contact Travis County TNR. The county lists 512-854-4215 on its permit pages. Have your address, parcel number and a description of the work ready.

If you want help thinking through system options before you apply, we can talk through the soils, the lot and the likely path. If you are near Lakeway or elsewhere in western Travis County, request a free estimate and share your plans. We will explain what we can, and point you back to the county for anything only it can answer.