Who issues a septic permit in Texas for a barndominium?
The local authorized agent issues it. An OSSF permit is required to construct, install, alter, extend or repair a septic system, and local programs may be stricter than the state minimum. An authorized agent is responsible for implementing 30 TAC 285 in its jurisdiction, has to run its program under the OSSF order, ordinance or resolution approved by the TCEQ executive director, and has to enforce chapter 285 and Health and Safety Code chapter 366. Delegation to a municipality is limited to the incorporated area, so a city agent stops at the city limit and the county agent picks up outside it.
That is why this page is county by county. The statewide chapter is the same everywhere. The office applying it, and what that office layers on top, change from lot to lot. A local authorized agent may adopt on-site sewage disposal standards stricter than state law or TCEQ rules, and those stricter standards control where they give greater public health and safety protection.
Septic is one approval inside a longer chain. The order the approvals come in, and which of them gate the others, is laid out in the full walkthrough of building a barndominium in Central Texas.
The agent: found by county in TCEQ's authorized agent lookup, which returns every agent in the county and the area each one serves.
The permit: required to construct, install, alter, extend or repair a system.
The planning materials: ruled on by the agent alongside the permit application.
The decision: approve or deny within 30 days of receipt, in writing on a denial, with an appeal to the agent's supervisory body.
The installer: anyone working as an OSSF installer, apprentice, maintenance provider or maintenance technician in Texas must be licensed or registered by TCEQ. Installer I covers standard systems. Installer II covers all system types.
Source: TCEQ, Getting a Permit for an On-Site Sewage Facility, read 2026-09-13.
Source: TCEQ publication RG-472, 30 TAC 285.10(a), read 2026-09-13.
Source: Texas Health and Safety Code Sec. 366.032(b), read 2026-09-13.
Source: TCEQ, Occupational Licenses: On-Site Sewage Facilities (Septic Systems), read 2026-09-13.
Source: TCEQ, On-site Sewage Facilities: Information for Regulators, read 2026-09-13.
Source: TCEQ On-Site Activity Reporting System, search by county, read 2026-09-13.
Does the 10 acre septic exemption apply to your tract?
In these six counties, assume it does not. The state rule is real and it is narrow. 30 TAC 285.3 exempts an OSSF from planning materials, permit and inspections when it serves a single family dwelling on a tract of ten acres or larger, meets all Subchapter D construction standards, causes no nuisance or groundwater pollution, keeps all parts at least 100 feet from the property line, disposes of effluent on the property, and is the only dwelling on the tract. Every one of those has to hold at the same time. A tract can clear the acreage easily and still fail on the 100 foot setback.
Then comes the override. 30 TAC 285.10 lets a local governmental entity adopt OSSF standards more stringent than the state chapter. Each stricter requirement has to be justified in writing on public health and safety grounds and reviewed by the TCEQ executive director before public notice. So a county cannot adopt a stricter rule casually, but it can adopt one, and several here have. Where the local standard is stricter, the local standard controls.
Here is where each of the six lands on it, in the counties' own words. Five state a position and all five set the acreage exception aside.
Near the water another layer sits on top. Inside LCRA's jurisdiction a permit is required before constructing or installing any on-site sewage facility, no matter the lot size. Acreage buys no exemption there.
Travis County: states no lot-size exemption at all. Every system in its jurisdiction is covered whatever the size of the lot, and the minimum lot size for a home on a septic system is one acre.
Burnet County: permits and inspects every on-site system whatever the size of the tract. It will not issue the septic permit without a building permit first.
Llano County: the county is the state's authorized agent and permits every system whatever the tract size.
Bastrop County: every septic installation or modification needs a county permit regardless of acreage. Minimum lot size is half an acre with a public water supply and one acre without one.
Caldwell County: requires an application, permit and inspection whatever the size of the tract. Minimum lot size is one acre.
Williamson County: the record here states no position on the ten acre exemption. Ask the Williamson County Engineer's Office whether it recognizes the state exemption on your tract, before you plan around it.
Source: TCEQ adopted rule text, 30 TAC Chapter 285, Rule Project No. 2021-030-285-CE, section 285.3, read 2026-09-13.
Source: TCEQ publication RG-472, On-Site Sewage Facility Rules Compilation, 30 TAC 285.10(b)(4), read 2026-09-13.
Source: Texas Health and Safety Code Sec. 366.032(b), read 2026-09-13.
Source: LCRA On-Site Sewage Facilities Rules, Section 10.05(b), read 2026-09-13.
Source: Travis County Transportation and Natural Resources, Development Services, read 2026-09-13.
Source: Burnet County On-Site Sewage Facilities and Development Services, read 2026-09-13.
Source: Llano County Development Services, read 2026-09-13.
Source: Bastrop County Development Services, read 2026-09-13.
Source: Caldwell County Development Ordinance, revised February 14, 2023, read 2026-09-13.
Source: Williamson County frequently asked questions, County Engineer, read 2026-09-13.
Which office holds the septic permit in each of the six counties?
It depends on the county and, near the lakes, on the address. The number of authorized agents runs from one across a whole county to eight inside a single county. Run the county through TCEQ's authorized agent search first. It returns every agent in that county and the area each one serves, which is the fastest way to see whether a city or the river authority sits between you and the county office.
Travis County has seven OSSF authorized agents: Travis County (the unincorporated county plus Leander, Manor, San Leanna and Webberville), the City of Austin, the Lower Colorado River Authority, West Lake Hills, Bee Cave, Mustang Ridge and Rollingwood. Travis County TNR is the state's authorized agent for the unincorporated county, and LCRA is the agent near Lake Travis. A separate trap sits on the other lake: any property with water frontage on Lake Austin or its tributaries is inside Austin Water's septic jurisdiction, no matter how the lot or the house or the drainfield sits. The whole permit chain is on the Travis County permit page.
Williamson County is the simple one. It has a single OSSF authorized agent, Williamson County, covering the entire county. No city or special district is separately authorized and LCRA does not appear. The program runs through the County Engineer's Office, applications go through the county's online portal only, and a Certificate of Compliance from the County Engineer has to be processed before the septic application is.
Burnet County has eight authorized agents: Burnet County, LCRA, Cottonwood Shores, Bertram, Burnet, Granite Shoals, Marble Falls and Horseshoe Bay. Granite Shoals is administered by LCRA and Bertram by Burnet County. The county publishes a link to the river authority's jurisdiction map and does not say which lake lots fall inside it, so the map is the check and not the county. The sequence and the two building permit classes are on the Burnet County permit page.
Llano County has three authorized agents: Llano County (the unincorporated county plus Horseshoe Bay outside LCRA jurisdiction), LCRA, and the City of Horseshoe Bay. Llano County Development Services permits the system, or LCRA does inside its water quality zone. The county's subdivision rules point lots inside the river authority's zone at that agency's rules.
Bastrop County has two authorized agents: Bastrop County for the entire county except the City of Bastrop, and the City of Bastrop for its city limits. LCRA does not appear. The permit comes from Bastrop County Environmental and Sanitation, and the development permit and the septic permit are applied for at the same time where there is no public sewer. Caldwell County has five: Caldwell County for the unincorporated county, plus Mustang Ridge, San Marcos, Uhland and Niederwald for their city limits. LCRA does not appear there either, and the Caldwell County Sanitation Department is the agent.
Source: TCEQ OARS county search, Travis County (CNTY_CD 227), read 2026-09-13.
Source: TCEQ OARS county search, Williamson County (CNTY_CD 246), read 2026-09-13.
Source: TCEQ OARS county search, Burnet County (CNTY_CD 27), read 2026-09-13.
Source: TCEQ OARS county search, Llano County (CNTY_CD 150), read 2026-09-13.
Source: TCEQ OARS county search, Bastrop County (CNTY_CD 11), read 2026-09-13.
Source: TCEQ OARS county search, Caldwell County (CNTY_CD 28), read 2026-09-13.
Source: TCEQ OARS county search, identical entry returned for Travis, Burnet and Llano counties, read 2026-09-13.
Source: TCEQ On-Site Activity Reporting System, search by county, read 2026-09-13.
Source: Austin Water, On-Site Sewage Facilities, read 2026-09-13.
Source: Travis County Transportation and Natural Resources, Development Services, read 2026-09-13.
Source: Williamson County frequently asked questions, County Engineer, read 2026-09-13.
Source: Burnet County On-Site Sewage Facilities and Development Services, read 2026-09-13.
Source: Llano County Development Services, read 2026-09-13.
Source: Bastrop County Development Services, read 2026-09-13.
Source: Caldwell County Development Ordinance, revised February 14, 2023, read 2026-09-13.
Does LCRA hold your septic permit on a Highland Lakes lot?
If the lot is inside LCRA's jurisdiction, yes. TCEQ designated LCRA as an authorized agent to administer TCEQ's on-site sewage facility rules and standards there. Five lakes are named in LCRA's OSSF rules: Lake Buchanan, Inks Lake, Lake Lyndon B. Johnson, Lake Marble Falls and Lake Travis. Buchanan, Inks, LBJ and Marble Falls are the four upper Highland Lakes. LCRA appears as an authorized agent in Travis, Burnet and Llano counties. It does not appear in Williamson, Bastrop or Caldwell, so on a lot in those three the lake question does not arise.
Inside that jurisdiction a permit is required before constructing or installing any on-site sewage facility, whatever the lot size. Allow up to 30 days from the date the application is submitted for a new system permit, not counting design or site complications. Build that into the closing calendar, not the construction calendar.
A second LCRA rule catches buyers. An inspection is required on every transfer of ownership before LCRA will approve the new owner for continued use. If you are buying a lake lot with a house and a system already on it, that inspection can turn up work you did not price. Ask for the result before you close.
The address settles it. LCRA publishes an address-searchable OSSF and watershed jurisdiction map at waterquality.lcra.org/ossf. Run the address through it first, and do the same on any lot you are still only considering. That map and the county agent search are the first two checks on a lake lot, and they sit at the front of a proper land and lot evaluation.
Source: LCRA On-Site Sewage Facilities Program, read 2026-09-13.
Source: TCEQ OARS county search, identical entry returned for Travis, Burnet and Llano counties, read 2026-09-13.
Source: LCRA On-Site Sewage Facilities Rules, Section 6, Area of Jurisdiction, read 2026-09-13.
Source: LCRA On-Site Sewage Facilities Rules, Section 10.05(b), read 2026-09-13.
Source: LCRA On-site Sewage Rules Frequently Asked Questions, read 2026-09-13.
Source: LCRA Water Quality Jurisdictions map, read 2026-09-13.
Source: TCEQ On-Site Activity Reporting System, search by county, read 2026-09-13.
Source: Travis County Transportation and Natural Resources, Development Services, read 2026-09-13.
Source: Burnet County On-Site Sewage Facilities and Development Services, read 2026-09-13.
Source: Llano County Development Services, read 2026-09-13.
How far inland does the lake septic zone reach?
LCRA regulates on-site sewage facilities within a 2,200 foot zone around the upper Highland Lakes and within a 2,000 foot zone around Lake Travis. The regulated area is built from two layers: a Restricted Zone at each lake, plus a Water Quality Zone extending 2,000 feet horizontally beyond the outer boundary of that Restricted Zone. The boundary is drawn, not stepped off a plat by eye.
There is a recorded conflict here, and it is worth knowing before someone gives you a number on the phone. LCRA's own pages say the Lake Travis OSSF zone is 2,000 feet. Travis County is reported to say 1,000 feet. Nothing on lcra.org checked in this session says 1,000 feet. That conflict is recorded, not resolved. Do not settle it with a tape measure or a mapping app. Ask LCRA and Travis County TNR which agency holds your specific address, take the answer from the jurisdiction map, and if the two offices disagree, get it in writing from both.
A different LCRA approval can apply to the same lot, and it is not a septic permit. The Highland Lakes Watershed Ordinance regulates construction of buildings, roads, paved storage areas and parking lots, plus any land-disturbing and construction activity including clearing, excavating, grading, contouring, mining and depositing refuse, waste or fill. It covers the Lake Travis watershed in Travis County, the Colorado River watershed in Burnet County, and a portion of Llano County, above the Regulated Pool Elevation of the Highland Lakes, as drawn on the official Ordinance Map.
A development permit under that ordinance is required if impervious cover will exceed 10,000 square feet and/or land disturbance will exceed one acre. A single-family residence may be built without that permit by filing a written notification with LCRA instead, if it creates under 10,000 square feet of impervious cover and disturbs under one acre. If it creates more than 10,000 square feet but still disturbs under one acre, the written notification route stays open only if the site meets the downstream buffer guidelines in the LCRA Technical Manual. The permit may not even be LCRA's to issue: eleven local governments administer part or all of the ordinance under interlocal agreements.
Source: LCRA On-Site Sewage Facilities Program, read 2026-09-13.
Source: LCRA On-Site Sewage Facilities Rules, Section 6, Area of Jurisdiction, read 2026-09-13.
Source: LCRA Water Quality Jurisdictions map, read 2026-09-13.
Source: LCRA Highland Lakes Watershed Ordinance program page, read 2026-09-13.
Source: LCRA Highland Lakes Watershed Ordinance, Section 1, Title and Scope, read 2026-09-13.
Source: LCRA Highland Lakes Watershed Ordinance program page, Required notifications and permits, read 2026-09-13.
Source: LCRA Highland Lakes Watershed Ordinance, Section 4.1(b), Written Notification, read 2026-09-13.
Source: LCRA Highland Lakes Watershed Ordinance program page, Interlocal agreements, read 2026-09-13.
Source: Travis County Transportation and Natural Resources, Development Services, read 2026-09-13.
Source: Burnet County On-Site Sewage Facilities and Development Services, read 2026-09-13.
Source: Llano County Development Services, read 2026-09-13.
What does the septic review decide, and what does a denial mean for the lot?
The agent rules on the planning materials and the permit application together, within 30 days of receipt. A denial arrives with a written explanation and an appeal to the agent's supervisory body. What the agent wants inside those planning materials, who may prepare them, and what site work has to happen before they are filed varies by office. Ask the office named for your county what its planning materials require and who is allowed to perform the site evaluation. Get that list before you pay anyone to walk the lot.
Three counties already tell you something about who draws the system and who builds it. In Williamson County a septic system over the Edwards Aquifer recharge zone has to be designed by a registered sanitarian or a professional engineer. In Caldwell County only a licensed installer may build the system. In Travis County the septic approval is a permit to construct first and a license to operate after.
The ground changes across these six counties. On the Edwards Plateau the soils are shallow and underlain by limestone, with many springs, stony hills and steep canyons, and faulting along the Balcones Fault Zone followed the uplift of that plateau, with streams crossing the zone recharging the aquifer where permeability is enhanced by dissolution of limestone. The Llano Uplift, whose core counties include Burnet and Llano, is a large granite batholith and the major structural feature of central Texas. At Inks Lake State Park in Burnet County, on the east edge of the uplift, pink Valley Spring gneiss juts up through the limestone. East and south the problem changes from rock to clay: Post Oak Savannah uplands are sands and sandy loams with a dense clay pan almost impervious to water under all soil types at only a few feet deep, and in the Blackland Prairies region Houston Black soil cracks 0.5 to 4 inches wide from the surface down 12 inches or more when dry. None of that decides the permit. The office holding your file does, on the planning materials it approves or denies.
Minimum lot sizes are the part no redesign gets around. One acre in Travis County for a home on a septic system. One acre in Caldwell County. In Bastrop County, half an acre with a public water supply or one acre without one. Ask the permitting office three questions in the same call: what a denial lets you resubmit, whether a different system type is allowed on this soil, and whether the drainfield can move elsewhere on the tract. Know the knock-on effect before you file. In Caldwell County the approved septic permit is one of the papers the Residential Construction Permit requires, so a septic denial stops the house permit too. In Burnet County the order runs the other way, and the building permit has to exist before the septic permit will issue.
Source: TCEQ, Getting a Permit for an On-Site Sewage Facility, read 2026-09-13.
Source: Texas Parks and Wildlife Department, Texas Ecoregions, read 2026-09-13.
Source: USGS, Karst Aquifers: Edwards Balcones Fault Zone Aquifer, read 2026-09-13.
Source: Texas Water Development Board, Report 360 Chapter 9, Paleozoic Aquifers of the Llano Uplift, read 2026-09-13.
Source: Texas Water Development Board, Report 360 Chapter 9, read 2026-09-13.
Source: Texas Parks and Wildlife Department, read 2026-09-13.
Source: Texas Parks and Wildlife Department, read 2026-09-13.
Source: USDA NRCS, Official Series Description, Houston Black Series, read 2026-09-13.
Source: Williamson County frequently asked questions, County Engineer, read 2026-09-13.
Source: Caldwell County Development Ordinance, revised February 14, 2023, read 2026-09-13.
Source: Travis County Transportation and Natural Resources, Development Services, read 2026-09-13.
Source: Bastrop County Development Services, read 2026-09-13.
Source: Burnet County On-Site Sewage Facilities and Development Services, read 2026-09-13.
Aerobic or conventional, and what maintenance follows the septic permit?
The office that holds your permit decides, on the planning materials it approves or denies. What you can check yourself is the installer's license class. Anyone operating as an OSSF installer, apprentice, maintenance provider or maintenance technician in Texas must be licensed or registered by TCEQ. Installer I covers standard systems, Installer II covers all system types. So if a lot may need an aerobic treatment unit, ask an installer which class they hold before you let them bid it, and verify it yourself in TCEQ's public license lookup for OSSF professionals rather than taking the card at face value.
The maintenance obligation starts after the house is finished, and it recurs. Inside LCRA's jurisdiction a maintenance contract is required for the first two years on an aerobic treatment unit. After two years the owner may do the maintenance, but only after taking the class and passing the test. That is a real fork: keep paying a provider, or go and get trained.
Outside LCRA's jurisdiction, ask the county office that holds your permit what maintenance it requires and for how long, and ask before you sign anything with an installer. The TCEQ license requirement is statewide. The maintenance rule attached to a system type is a local program question, and the record here states it only for LCRA.
One more license to check on the same call. Plumbers in Texas are licensed by the state through the Texas State Board of Plumbing Examiners, which runs a public license lookup. Electricians are licensed by TDLR, non-exempt electrical work must be done through a licensed electrical contractor, and TDLR runs its own license search. The independent builder running your job holds no state license, because Texas does not require one, so the trade licenses are the documents that actually verify.
Source: TCEQ, Occupational Licenses: On-Site Sewage Facilities (Septic Systems), read 2026-09-13.
Source: TCEQ, On-site Sewage Facilities: Information for Regulators, read 2026-09-13.
Source: LCRA On-site Sewage Rules Frequently Asked Questions, read 2026-09-13.
Source: Texas State Board of Plumbing Examiners, read 2026-09-13.
Source: Texas State Board of Plumbing Examiners, read 2026-09-13.
Source: Texas Department of Licensing and Regulation, Electricians program, read 2026-09-13.
Source: Texas Department of Licensing and Regulation, read 2026-09-13.
Source: Office of the Texas Governor, Business Permit Office, Texas Business Licenses and Permits Guide, read 2026-09-13.
What happens if the septic system fails and needs an emergency repair?
Emergency repairs need no permit, but they must be reported to the permitting authority in writing within 72 hours after repairs begin. Read that timing carefully. The clock starts when the repair work starts, and the report goes to whichever office holds your file. Know that office and its address before anything fails, because a failure is not the moment to start working out whether the county or the river authority is your agent.
Everything short of an emergency repair is a permit. An OSSF permit is required to construct, install, alter, extend or repair a septic system. A second dwelling, a line extended to a shop with a bathroom, a replaced field: all inside that list. Local programs may be stricter than the state minimum, so the local rule is the one to read.
Selling later brings one more requirement on a lake lot. Inside LCRA's jurisdiction an inspection is required on every transfer of ownership before LCRA will approve the new owner for continued use. Keep one file with the permit, the planning materials, every maintenance record, and in Travis County the license to operate that follows the permit to construct. That turns the inspection into a formality instead of a negotiation.
Source: TCEQ, Getting a Permit for an On-Site Sewage Facility, read 2026-09-13.
Source: Texas Health and Safety Code Sec. 366.032(b), read 2026-09-13.
Source: LCRA On-site Sewage Rules Frequently Asked Questions, read 2026-09-13.
Source: Travis County Transportation and Natural Resources, Development Services, read 2026-09-13.
Does the Edwards Aquifer add a second approval in Travis and Williamson?
On parts of those two counties, yes, and it is separate from the septic permit with its own clock. The Edwards Aquifer Protection Program covers eight Texas counties: Kinney, Uvalde, Medina, Bexar, Comal, Hays, Travis and Williamson. In the Austin region it covers Williamson, Travis and Hays counties, handled by the TCEQ Austin Regional Office at (512) 339-2929. Burnet, Llano, Bastrop and Caldwell are not on that list.
The zone the parcel sits in sets which plan applies. On the recharge zone, where the aquifer rock units crop out, a Water Pollution Abatement Plan is required for any regulated activity, approval is required before construction starts, and there is no acreage floor at all. In the contributing zone, the watershed upgradient of the recharge zone, a Contributing Zone Plan is triggered when activities disturb at least five acres or are part of a larger plan of development or sale, and below that no Edwards Aquifer protection plan is needed. The five acre trigger is a contributing zone concept only. If a site sits partly on each, the whole site is treated as recharge zone and a WPAP is required, and the same escalation applies to a transition zone site that drains back to the recharge zone.
The timeline is the reason to check this before the septic application, not alongside it. Administrative review takes up to 30 days, technical review of an administratively complete application takes 90 days, and construction cannot begin until approval issues. There is relief for a single house: a single-family residence may not need its own plan if it is in a master community with an approved plan, or sits on a lot larger than five acres with only that one residence, or keeps impervious cover to 20 percent or less of the legal property. Check the parcel in the TCEQ Edwards Aquifer Map Viewer and print the map to submit with an application. And remember the Williamson rule that ties the two approvals together: a septic system over the recharge zone there has to be designed by a registered sanitarian or a professional engineer.
Source: TCEQ GIS metadata, Edwards Aquifer Recharge Zone - Chapter 213 Rules (TSMS), quoting 30 TAC 213.3(8), read 2026-09-13.
Source: TCEQ Edwards Aquifer Protection Program home page, read 2026-09-13.
Source: TCEQ GIS metadata, quoting 30 TAC 213.3(25), read 2026-09-13.
Source: TCEQ GIS metadata, quoting 30 TAC 213.22(2), read 2026-09-13.
Source: TCEQ GIS metadata, quoting 30 TAC 213.3(34), read 2026-09-13.
Source: TCEQ, Water Pollution Abatement Plan page, read 2026-09-13.
Source: TCEQ, What Plans You Might Need, recharge zone branch, read 2026-09-13.
Source: TCEQ, Contributing Zone Plan page, read 2026-09-13.
Source: TCEQ, Edwards Aquifer Protection Program: What Plans You Might Need, read 2026-09-13.
Source: TCEQ, What Plans You Might Need, contributing zone branch, read 2026-09-13.
Source: TCEQ, Edwards Aquifer Private Residences page, read 2026-09-13.
Source: TCEQ, Edwards Aquifer Map Viewer page, read 2026-09-13.
Source: Williamson County frequently asked questions, County Engineer, read 2026-09-13.
Source: Travis County Transportation and Natural Resources, Development Services, read 2026-09-13.
What should you do first on a lake lot?
Two lookups, in this order, before you talk to anyone. Run the address through LCRA's address-searchable OSSF and watershed jurisdiction map at waterquality.lcra.org/ossf. Then run the county through TCEQ's authorized agent search, which returns every agent in the county and the area each one serves. Between them you will know whether the county, a city or the river authority holds your septic permit. If the lot sits near Lake Travis, call both Travis County TNR and LCRA, because the zone distances on record disagree and the map is the tiebreaker.
Then follow your county's sequence. These are not interchangeable, and getting the order wrong costs weeks:
A driveway approval sits near the front of several of these chains, because the 911 address can depend on it. In Burnet County driveway approval must be in hand before a 911 address is assigned, and the precinct commissioner sets culvert location, length and diameter at a site meeting. In Llano County nothing may be installed on a county right of way, driveways and culverts included, without the precinct commissioner's written permission. TxDOT approves a driveway onto a Farm to Market, Ranch Road or State Highway.
Do this work before the lot closes, not after. The septic answer changes what the site costs, and on some lots it changes whether the house you drew will fit at all. Once the permit path is known it feeds into the build sequence and the contract, which is where barndominium construction picks it up.
Burnet County: 911 address first, then the building permit, then the septic permit. The county will not process an incomplete packet.
Llano County: a county development permit, which is also how the property gets its 911 address, then the septic permit from the county or from LCRA inside its zone. The county asks for seven to 10 business days on a review outside the floodplain, and longer for floodplain work, septic and commercial projects.
Williamson County: a Certificate of Compliance from the County Engineer's office first, which is the floodplain check and has to be processed before a septic application will be. Applications go through the county's online portal only. A lot in a recorded subdivision may already carry a Certificate of Compliance in its plat notes.
Travis County: any development in the county requires a permit, and the county's definition of development includes on-site sewage facilities, driveways, clearing and grading. Septic is a permit to construct, then a license to operate.
Bastrop County: the development permit and the septic permit are applied for at the same time where there is no public sewer, and the driveway and 911 address ride on the same county application.
Caldwell County: the 911 address is required for the septic permit, and the approved septic permit is one of the papers the Residential Construction Permit requires, so the chain runs address, septic, then house.
Source: LCRA Water Quality Jurisdictions map, read 2026-09-13.
Source: TCEQ On-Site Activity Reporting System, search by county, read 2026-09-13.
Source: LCRA On-Site Sewage Facilities Program, read 2026-09-13.
Source: Burnet County On-Site Sewage Facilities and Development Services, read 2026-09-13.
Source: Llano County Development Services, read 2026-09-13.
Source: Williamson County frequently asked questions, County Engineer, read 2026-09-13.
Source: Travis County Transportation and Natural Resources, Development Services, read 2026-09-13.
Source: Bastrop County Development Services, read 2026-09-13.
Source: Caldwell County Development Ordinance, revised February 14, 2023, read 2026-09-13.
Questions people ask
- Do I need a septic permit in Texas if my barndominium sits on more than ten acres?
- In these six counties, assume yes. The state exemption in 30 TAC 285.3 requires every one of its conditions at once, including the 100 foot setback from every property line and being the only dwelling on the tract, and 30 TAC 285.10 lets a local agent adopt stricter standards. Travis, Burnet, Llano, Bastrop and Caldwell each state that they permit every system whatever the tract size. Williamson states no position in this record, so ask the Williamson County Engineer's Office. Inside LCRA's jurisdiction a permit is required at any lot size.
- Who holds my septic permit if the lot is near Lake Travis?
- Either Travis County TNR or the Lower Colorado River Authority. Travis County has seven OSSF authorized agents and LCRA is one of them. Check the address on LCRA's jurisdiction map at waterquality.lcra.org/ossf, then call both offices. LCRA's own pages put the Lake Travis OSSF zone at 2,000 feet while Travis County is reported to say 1,000 feet, and that conflict is unresolved, so do not decide it with your own measurement. Separately, any property with water frontage on Lake Austin or its tributaries falls under Austin Water.
- How long does a septic permit take?
- The permitting authority must approve or deny the planning materials and the permit application within 30 days of receipt. LCRA asks for up to 30 days from the date the application is submitted for a new system permit, not counting design or site complications. Llano County asks for seven to 10 business days on a review outside the floodplain, and longer for floodplain work, septic and commercial projects. A denial arrives with a written explanation and an appeal to the agent's supervisory body.
- Can I repair a failed septic system without a permit?
- Emergency repairs need no permit, but they must be reported to the permitting authority in writing within 72 hours after repairs begin. The 72 hours runs from when the work starts. Anything that is not an emergency repair does need a permit: constructing, installing, altering, extending or repairing a system all require one, and local programs may be stricter than the state minimum.
- Who is allowed to install the system?
- Anyone operating as an OSSF installer, apprentice, maintenance provider or maintenance technician in Texas must be licensed or registered by TCEQ. Installer I covers standard systems and Installer II covers all system types, so ask which class an installer holds before letting them bid a lot that may need an aerobic unit. Caldwell County states that only a licensed installer may build the system. Verify the license in TCEQ's public license lookup for OSSF professionals.
- Does an aerobic system come with a maintenance contract?
- Inside LCRA's jurisdiction, yes. A maintenance contract is required for the first two years on an aerobic treatment unit. After those two years the owner may do the maintenance, but only after taking the class and passing the test. Outside LCRA's jurisdiction, ask the county office that holds your permit what maintenance it requires and for how long, and get the answer before you sign an installer's contract.
Four fields, no email
Get a free estimate for your build
Your county and what you want to build. Free. No obligation. No fee to you at any point.
Tell us where the land is and what you want to build: the pad, the septic, the shell, the finish. Your request goes to one independent builder, and taking the project is their call.