Verified against county records · page updated September 28, 2026 · rules change — confirm with the agent before applying
A septic permit from Guadalupe County itself costs $400 for a standard system, $500 for an aerobic or other advanced-treatment system, and $600 for a multi-unit or commercial job, each including the state’s $10 fee. That price only applies outside city limits. Inside Seguin, San Marcos or New Braunfels, that city runs its own program with its own fee, and none of the three matches the county’s number.
Four separate TCEQ-authorized agents permit septic systems somewhere in Guadalupe County, and your address decides which one, not your mailing city.
Guadalupe County Environmental Health (Authorized Agent 620087) 310 W I-10, Seguin, TX 78155 Phone: (830) 303-8858 · Email: permits@guadalupetx.gov Covers all unincorporated county land and any incorporated area without its own program.
City of Seguin (Authorized Agent 620311) 108 E Mountain St, Seguin, TX 78155 Phone: (830) 401-2437 Covers inside Seguin city limits. Seguin’s own OSSF fee schedule could not be located online; call to confirm current pricing before budgeting.
City of San Marcos (Authorized Agent 620289) 630 E Hopkins St, Bldg. 5, San Marcos, TX 78666 Phone: 512-393-8444 · Email: healthinfo@sanmarcostx.gov Covers the Guadalupe County side of San Marcos city limits (a separate program covers the Hays County side).
City of New Braunfels (Authorized Agent 620343) 550 Landa St, New Braunfels, TX 78130 Inspection requests: 830-221-4031, option 5 Covers the Guadalupe County side of New Braunfels city limits (a separate program covers the Comal County side).
TCEQ’s 2025 authorization data confirms the split is real, not just theoretical: the county authorized 385 systems that year, Seguin authorized 20 inside its own limits, New Braunfels’ Guadalupe-side authorized 3, and San Marcos’ Guadalupe-side authorized none. For the statewide picture of who permits septic where, see our permitting-authority directory.
Outside any city, the county’s own fee schedule sets the price by system type, and it hasn’t changed since an October 2025 revision.
| Application type | Guadalupe County | City of Seguin | City of San Marcos | City of New Braunfels |
|---|---|---|---|---|
| Standard/conventional new system | $400 | Not published | $415 (new install or repair needing updated plans) | $160 |
| Aerobic / advanced treatment | $500 | Not published | $415 | $185 (proprietary) |
| Multi-unit / commercial | $600 | Not published | Not published | Not published |
| Repair, connection, alteration, or expansion | $200 each | Not published | $415 if plans need updating | Not published |
| Re-inspection | $200 (fee schedule) or $100 (process document — see note below) | Not published | $250 | Not published |
| After-hours inspection | Not published | Not published | +$250 | Not published |
The county’s $10 TCEQ state fee is folded into the three application totals above. Guadalupe County’s own documents disagree on the re-inspection fee: the current fee schedule prints $200, but the county’s own permit-process handout, revised more recently, states installers are charged $100 when a system isn’t ready at inspection time. This page states both numbers rather than picking one; confirm at (830) 303-8858 before budgeting a specific figure. Seguin’s fee could not be found published anywhere online; call (830) 401-2437 to get a current number rather than assuming it matches the county’s. Statewide fee context is in our Texas permit fee guide.
Guadalupe County publishes an eight-step sequence, and every step outside city limits runs through the same office.
San Marcos runs a comparable six-step sequence through its own MyGovernmentOnline portal rather than paper submission, with a field inspection at the reviewer’s discretion before the ATC issues and a required pass-before-cover inspection identical in spirit to the county’s step 7. New Braunfels requires the same core submittals, application, soil evaluation results, a scaled technical drawing, plus a copy of the installer’s TCEQ license attached up front, which the county and San Marcos don’t ask for at application time.
Site evaluation always requires a licensed professional; construction usually does, with one notable exception. A Registered Sanitarian, licensed Site Evaluator, or professional engineer must perform the site and soil evaluation everywhere in the county, no exceptions. Construction generally requires a TCEQ-licensed Installer I or II, matched to system complexity. The exception: Guadalupe County’s own FAQ states that a property owner may install or repair an OSSF on their own single-family dwelling without an installer license, under 30 TAC §30.244, provided all permitting, construction, and maintenance requirements are still met and the site evaluation still comes from a licensed evaluator. That’s a real option for an owner-builder here that isn’t available in every county; verify it still applies to your specific system type before planning around it. Aerobic and other maintenance-contract systems separately require an ongoing TCEQ-registered maintenance provider, unless the owner is themselves licensed, trained under the applicable statute, or holds a Class D+ wastewater license or a completed TOWA Basic Maintenance Course.
Some neighboring counties add a second state approval before the county can issue a permit; Guadalupe does not. Texas requires an Edwards Aquifer Protection Plan under 30 TAC Chapter 213 for construction over the recharge or contributing zones, but that chapter names exactly eight counties in both its general-provisions and contributing-zone subchapters: Medina, Bexar, Comal, Kinney, Uvalde, Hays, Travis and Williamson. Guadalupe isn’t on either list. That means a Guadalupe County application clears Chapter 285’s general rules and the county’s own Order, without a second TCEQ regional-office sign-off in the sequence. The county’s Order does still exceed the state floor on its own terms: Section 10(D) requires a permit “regardless of tract size,” so the state’s 10-acre exemption for a single dwelling doesn’t operate here, and Section 10(A) sets a one-acre minimum lot for new subdivisions using septic.
Everything below comes from each authority’s own site; nothing is paraphrased or summarized from a third party.
Find the county’s documents at guadalupetx.gov/page/eh.ossf; San Marcos at sanmarcostx.gov/4275/On-Site-Sewage-Facilities; New Braunfels forms are distributed by its Health and Food Safety division, 830-221-4031 option 5.
Outside any city, $400 for a standard system, $500 for aerobic or advanced treatment, and $600 for multi-unit or commercial, all including the state’s $10 fee. Inside Seguin, San Marcos or New Braunfels, that city’s own fee applies instead — San Marcos charges $415 for new installs or plan-affecting repairs, New Braunfels charges $160 (standard) or $185 (proprietary), and Seguin’s fee isn’t published online, so call (830) 401-2437 before budgeting.
Yes. Section 10(D) of the county’s OSSF Order requires a permit “regardless of tract size,” so the state’s 10-acre exemption for a single dwelling does not apply anywhere in Guadalupe County, in the county’s jurisdiction or inside any of the three cities.
On your own single-family home, yes — the county’s FAQ states a property owner may install or repair an OSSF without an installer’s license under 30 TAC §30.244, as long as the site evaluation still comes from a licensed evaluator and every permitting and construction requirement is met. This applies to the county’s own program; confirm the same holds if you’re inside Seguin, San Marcos or New Braunfels city limits, since each city runs its own rules.
No. The eight counties named under 30 TAC Chapter 213’s Edwards Aquifer rules are Medina, Bexar, Comal, Kinney, Uvalde, Hays, Travis and Williamson. Guadalupe County sits outside all of them, so no separate Edwards Aquifer protection plan is required here.
Up to 30 days from a complete application, per the county’s own FAQ and TCEQ rule §285.3(c). That clock only starts once the application is complete; an incomplete packet resets it. San Marcos publishes no fixed timeline beyond its six-step sequence; ask at application time.
The county’s fee schedule and its process document give two different re-inspection figures, $200 and $100, so this page can’t tell you which applies to your case. Either way, the system can’t be covered until it passes, and a second visit is billed. Call (830) 303-8858 to confirm the current amount before scheduling.
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