Verified against county records · sources last read September 3, 2026 · rules change — confirm with the agent before applying
A new septic permit in Kendall County costs $300 for a system designed under 500 gallons a day and $600 at or above it, from a fee schedule the Commissioners Court approved on August 28, 2023. The county also requires a professional engineer or professional sanitarian to design every septic system, including the standard ones Texas lets an installer or site evaluator plan, and it requires a permit on every tract regardless of acreage. Both rules have been in the county’s TCEQ-approved Order since 2006.
Kendall County took the owner-and-installer planning option off the table in 2006, and the design it requires instead costs more than the permit. Under state rule 30 TAC §285.5(a)(1), the owner or installer may prepare the planning materials for a conventional system on a suitable site. Kendall County’s Order No. 03-13-2006-B, section 10(D), removes that option for on-site sewage facilities (OSSF, the rules’ term for a septic system): “All OSSF planning materials shall be prepared by a professional engineer or professional sanitarian (with appropriate seal, date, and signature) including those systems excluded in 30-TAC 285 Appendix B, Table IX.” The county’s application form repeats it in plain words: “Design required by Registered Sanitarian or Licensed Engineer as applicable in State & County rules on all septic types.”
Budget for the permit, the design and the site evaluation before any digging starts; our new septic system cost guide puts design fees in statewide context. The Order was adopted March 13, 2006 and approved by TCEQ’s executive director on March 24, 2006. The county’s 2022 Development Rules restate its four local amendments word for word in section 5.5.C.9.
You cannot apply for the septic permit first. The county’s own pages set the sequence: “The 911 Rural Address and Access Permit must be obtained before applying for Development, Septic, and/or Well Permits,” and “A Development Permit is required to proceed with any property development and the issuance of septic or well permits.”
That is three steps, all handled by the County Engineer’s Office at 400 E. Blanco Road in Boerne:
Nothing is filed online. The Development Rules require every application “in both printed and digital form,” and “No hand drawn plans will be accepted.”
The OSSF fee is set by design flow in gallons per day (gpd), not by system type. From the schedule effective September 1, 2023:
| Line item | Fee |
|---|---|
| OSSF permit, system under 500 gpd | $300 |
| OSSF permit, system 500 gpd or more | $600 |
| OSSF reinspection, under 500 gpd | $150 |
| OSSF reinspection, 500 gpd or more | $300 |
| Residential access permit | $100 |
| Address request / verification | $100 |
| Floodplain development permit, residential | $200 minor / $300 major |
| Commercial development permit | $1,000 |
A typical single-family home designs under 500 gpd, so an aerobic spray system and a conventional trench pay the same $300 here. Neighboring Comal County also prices by flow; most Texas counties price by technology. “Reinspection fees are due prior to scheduling reinspection,” the sheet says.
The schedule omits two things. It has no repair, alteration, transfer or commercial OSSF line; the Development Rules require a septic permit “prior to the installation, repair or retrofit of any septic system,” and the application form lists Repair, Modified and Replacing Failed OSSF as reasons, so a repair goes through the same application. And the $10 state fee that Texas Health and Safety Code Chapter 367 attaches to every permit appears nowhere on the sheet or the form. The county does collect and remit it (the April 14, 2026 bills list carries a $1,060 “TCEQ Septic Fee” line), but whether it sits inside the $300 or is added on top is not published. Ask the office before you pay. Statewide fee comparisons are in our Texas permit fee index.
The state’s ten-acre exemption does not operate in Kendall County, and it has not since 2006. Order section 10(C): “A permit shall be required for all On-Site Sewage Facilities within Kendall County’s area of jurisdiction regardless of acreage.” Two of the three competitor pages we checked still tell readers the exemption “may” apply here. It does not. The state rule and the counties that keep it are covered in our Texas ten-acre rule guide.
For a subdivision created after March 13, 2006, a lot on public water needs at least 1 acre, and a lot on its own well needs at least 3.00 acres. Those are Order sections 10(A) and 10(B); the state floors are half an acre and one acre. Plats the Commissioners Court approved before that date are exempt from the county minimum. The Development Rules’ Table 5-1 adds road frontage of 100 feet for a public-water lot and 250 feet for a well-and-septic lot, and sets 1 acre as the minimum commercial site on septic.
The 3-acre well rule sits beside a groundwater concern. The Development Rules open by noting the county lies in a Texas Water Development Board Priority Groundwater Management Area, with Cow Creek Groundwater Conservation District regulating wells. Kendall County is not, however, an Edwards Aquifer county. TCEQ’s protection program runs in Williamson, Travis, Hays, Comal, Bexar, Medina, Uvalde and Kinney counties, and 30 TAC §213.3 draws the regulated aquifer through those same eight. No TCEQ aquifer plan gates a Kendall County permit, whatever a competitor page says about Boerne.
Every aerobic system needs a maintenance contract and a recorded affidavit, and the affidavit follows the deed. The county’s Onsite Sewage page: “Affidavit to the Public form required on all aerobic septic systems. The original Affidavit to the Public must be recorded at the Kendall County Clerk’s office. A maintenance contract signed by the property owner is also required on all aerobic septic systems. The contract is provided by the licensed septic installer.”
The affidavit puts the next buyer on notice that the system “requires a maintenance contract with an approved maintenance company for use of the system,” and commits the seller to request a transfer of the permit to operate at sale. Contract contents are in our aerobic maintenance contract guide, running costs in the aerobic system cost guide. Whether the county lets a homeowner take over maintenance after the initial term, as the state rule allows, is not stated in any county document; ask before you sign a contract you expect to drop.
The permit itself lasts a year. The application form: “If the installer does not request a construction inspection by the permitting authority within one year of the issuance of the authorization to construct, the authorization to construct expires, and the owner will be required to submit a new application and application fee.”
The county commits to 30 days, counted from a complete application. Development Rules section 3.6.D: “The County shall approve or deny a Septic Permit within 30 days of determination of application completeness.” The county’s web page and the form say “within 30 days of receiving an application,” but the Rules also say an incomplete application “will not be processed,” so completeness is the clock. A competitor prints “10-14 working days.” The county publishes no such figure.
Three things no county document states: how much notice the installer must give to schedule the construction inspection, who makes that call, and whether Boerne, Fair Oaks Ranch or Comfort have a contract for the county to permit inside city limits. TCEQ’s agent record says the county serves the “entire County” and lists no city agent. If your lot is inside a city limit, ask the county office which desk permits you before hiring a designer.
Of the 224 systems the county authorized in 2025, 146 were surface-irrigation aerobic units and only 8 were standard trenches or beds. TCEQ’s report for calendar 2025, dated April 27, 2026, gives the rest: 38 leaching-chamber systems, 22 absorptive mounds, 10 drip. Leaching chambers jumped from 4 in 2024 to 38, and mounds fell from 65 to 22, so the conventional share is moving even as spray stays dominant. The county’s own annual report counts 261 OSSF permits for 2025; that counts permits issued, a different measure from TCEQ’s authorizations to construct.
The soil explains the spray share. In the NRCS soil survey for Kendall County, every major soil component rates “Very limited” for a septic tank absorption field, and our analysis of that survey puts depth to bedrock as the lead limitation on about 85 percent of county acreage, the Brackett-Real, Eckrant-Comfort and Doss-Brackett uplands. Slow water movement in the Krum and Denton clays limits most of the rest. On this ground the site evaluation decides what you may build. The Census Bureau’s Vintage 2025 estimates put the county at 53,289 residents on July 1, 2025, up 1,312 from 2024, almost all domestic migration.
One office handles every form.
| Office | Kendall County Engineer’s Office (Development Management) |
| Address | 400 E. Blanco Road, Boerne, TX 78006 |
| Phone | (830) 249-9343 |
| development@co.kendall.tx.us | |
| Hours | Monday–Friday 8 a.m.–4 p.m., closed noon–1 p.m. |
| OSSF records | Joy Cameron, (830) 331-8253 |
| TCEQ agent record | Kendall County Authorized Agent, AR 620117, entire county |
Forms, all on the county’s Forms & Permits page: Septic Permit application, Affidavit to the Public, Agent Designation Form, Development Permit Application and Checklist, Address Request Form, Access Application, and the Notice to Development Applicant for flood zones. The Order itself is not hosted by the county; TCEQ serves it through its authorized-agent database. The state rules beneath it are in our Texas septic regulations guide; provider listings are on the Kendall County hub; every other county’s permit desk is in who issues septic permits in Texas.
$300 for a system designed under 500 gallons per day, $600 at or above that; reinspections are $150 or $300. The schedule took effect September 1, 2023 and prices by design flow, so aerobic and conventional pay the same. Whether the $10 state fee is included is not published.
Yes, an engineer or a registered sanitarian, for every system. Order section 10(D) requires sealed planning materials on all systems, including the conventional ones the state would let an installer plan. Budget for the design before the permit.
No. Order section 10(C) requires a permit “regardless of acreage,” and has since 2006.
Thirty days from the day the county decides your application is complete. That is the Development Rules’ wording. Incomplete applications are not processed, so the address, access and development permits need to be in hand first.
A maintenance contract and an Affidavit to the Public recorded with the County Clerk, on every aerobic system. The county says the contract comes from the licensed installer. If you are inside Boerne city limits, confirm with the county office which authority permits your lot.
Every fee on this page was read from the county’s fee schedule approved August 28, 2023 and effective September 1, 2023, the only engineer’s schedule the county linked on September 3, 2026. Rule text is quoted from Kendall County Order No. 03-13-2006-B as served by TCEQ’s authorized-agent database, which is the only copy online; the county’s Development Rules of November 14, 2022 restate the same sections, and the two were compared line by line. The $10 state fee question, the repair-fee question, homeowner self-maintenance, inspection notice and city-limits jurisdiction are all unpublished by the county and are logged as calls rather than guessed.
System counts come from TCEQ’s Types of Systems Installed reports for 2023, 2024 and 2025; in each year the type columns sum to the stated county total. Soil limitation figures are our own analysis of the NRCS SSURGO survey for Kendall County (TX259, saved September 4, 2025) queried through Soil Data Access; the survey is association-level, so the percentages describe map units, not individual lots. Population is from the Census Bureau’s Vintage 2025 county file dated March 26, 2026, and no growth rank is stated because none is published for this county.
Three competitor pages were read against the county’s documents; one prints a $340 fee and eight sub-fees that do not exist, and all three place the county on the Edwards Aquifer recharge zone, which TCEQ’s program map does not.
Pumping, an inspection, or help fixing a septic system: tell us once and we send it to up to 3 verified pros. Free, no spam, delete your request anytime.
Secure form. Sent over an encrypted connection to up to 3 verified pros. Never sold to data brokers, and you can have your request deleted anytime.