Kendall County Septic Regulations: What Homeowners Need to Know in 2026

Kendall County septic permits cost $340, require 1-3 acre lots, and most properties need aerobic systems due to shallow Hill Country limestone bedrock.

Kendall County sits in the heart of the Texas Hill Country, and the geology shows it. Shallow limestone, steep slopes, and clay pockets make conventional septic systems impossible on a majority of properties. Add in Edwards Aquifer recharge zone requirements for parts of the county, and you've got some of the most complex septic permitting in Texas. According to TCEQ permitting data, Texas issued 43,215 new septic permits statewide in 2024, and a growing share of those are in fast-developing Hill Country counties like Kendall.

This guide covers who handles permits, fees, the application process, lot size rules, Hill Country geology challenges, Edwards Aquifer rules, aerobic maintenance, enforcement, and costs. If you're building or buying in the Boerne area, here's what you need to know.

Who Handles Septic Permits in Kendall County?

The Kendall County Environmental Health Department issues all septic permits in unincorporated Kendall County, operating as an authorized agent of TCEQ.

The office is in Boerne on East San Antonio Avenue. Staff handle plan reviews, permit issuance, and inspections for all septic systems in the county's jurisdiction. For properties in the Edwards Aquifer recharge zone, you'll also need separate approval from TCEQ's Edwards Aquifer Protection Program.

Contact information:

Detail	Information
Office	Kendall County Environmental Health Department
Address	204 E. San Antonio Ave, Boerne, TX 78006
Phone	(830) 331-8251 or (830) 331-8253
Hours	Monday-Friday, 9:00 AM - Noon and 1:00 PM - 5:00 PM
Website	kendallcountytx.gov/394/Onsite-Sewage

If you're building a new home, the permitting sequence matters. You need a 911 physical address first, then your development permit, then your septic permit, then your building permit. Getting these out of order can add weeks to your timeline.

What Are the Septic Permit Types and Fees in Kendall County?

Residential septic permits in Kendall County cost $340, which includes the TCEQ research fund contribution. Repairs and tank replacements run $100-$200.

Here's the current fee schedule:

Permit Type	Fee	Notes
New residential septic permit	$340	Includes TCEQ contribution
Commercial septic permit	$510	New installation
Tank replacement only (no field work)	$100	Existing field stays
Soil absorption system repair only	$200	Field repair/replacement
Re-inspection	$50	If initial inspection fails
Variance request	$70	For non-standard designs
Permit plan revision	$50	Changes to approved plans
Tank abandonment	$50	Proper closure of old system
Non-compliance fee	2x standard	Double fee for unpermitted work

These are county fees only. Professional site evaluation and system design add substantially to the total:

Professional Service	Cost Range
Soil site evaluation (certified classifier)	$800-$1,500
System design (Registered Sanitarian)	$1,200-$2,500
System design (Professional Engineer)	$2,500-$5,000

Aerobic systems require PE design rather than sanitarian design, which is why they typically incur the higher design costs. Budget $2,000-$5,500 for permits, evaluation, and design before installation even begins.

The 10-acre exemption: Under TCEQ rules (30 TAC Chapter 285), properties of 10 acres or more with a single home and single septic system may not need a county permit if the disposal area is at least 100 feet from all property lines. The system still must meet every technical standard. Kendall County has increased enforcement audits of claimed exemptions, so make sure you truly qualify.

How the Kendall County Septic Permit Process Works

The complete process from site evaluation to operating license typically takes 4-10 weeks. County review runs 10-14 working days for complete applications.

Here's the step-by-step process:

1. Get your 911 address. Before anything else, apply for a physical address through the Kendall County Development Department. This takes about one week.

2. Hire a site evaluator. A state-certified soil classifier evaluates your property by digging test pits, characterizing soil at various depths, measuring bedrock depth and water table levels, and assessing slope. In the Hill Country, this step is critical because it determines which system types are feasible.

3. System design. Based on the soil evaluation, a Registered Sanitarian or Professional Engineer designs your system. Plans must be drawn to engineer scale and show all buildings, structures, driveways, property lines, easements, wells, and any agricultural uses on adjacent properties.

4. Submit application. Bring the complete package to the Environmental Health office in Boerne: original soil analysis, three copies of design plans, completed application form, and permit fee.

5. County review. Applications are reviewed in order received. Standard review takes 10-14 working days. Incomplete applications trigger resubmission cycles that add 5-7 days each time. During peak season (March through June), expect 14-18 working days.

6. Authorization to construct. Once approved, you have 12 months to complete installation. Only a TCEQ-licensed installer can do the work.

7. Inspection. Call Environmental Health at least 24 hours in advance to schedule. The inspector verifies everything matches approved plans. Failed inspections require a $50 re-inspection fee.

8. License to operate. Pass inspection and you receive your operating license, which establishes your maintenance schedule and operational requirements.

What Are the Lot Size Requirements for Septic in Kendall County?

Kendall County requires 3 acres with a private well and septic, or 1 acre with public water and septic. These are among the strictest lot minimums in the Hill Country.

Water Source	Minimum Lot Size	Min. Road Frontage
Private well + septic	3 acres	250 feet
Public water + septic	1 acre	100 feet

These minimums are significantly stricter than the state baseline (0.5-1 acre under TCEQ rules). Kendall County set these higher thresholds to protect groundwater and account for the Hill Country's challenging soil conditions.

Coordination with the Cow Creek Groundwater Conservation District: If you're installing both a well and a septic system, both permits must show the 100-foot minimum separation between the two. Contact the Cow Creek GCD at (830) 816-2504 to coordinate.

Why Does Hill Country Geology Make Kendall County Septic Systems Different?

Roughly 60% of Kendall County properties hit limestone bedrock within 18-24 inches of the surface. This single factor rules out conventional septic systems on most lots and drives up installation costs.

The Hill Country's geology creates four major challenges for septic systems:

Shallow limestone bedrock. When your site evaluator finds limestone within 2 feet, conventional gravity drain fields won't work. You'll need an aerobic system, low-pressure dose system, or mound system instead. All of these cost more.

Steep slopes. Kendall County's rolling terrain means many properties have slopes exceeding 15-20%. Steep grades limit where you can place a drain field and often require low-pressure dosing or pumped systems rather than gravity flow. Terracing and grading add $1,000-$2,500 to the project.

Clay lenses. Even where bedrock isn't shallow, clay layers in the soil can create perched water tables that restrict infiltration. Wastewater builds up along the clay boundary rather than filtering down. These properties typically need aerobic treatment with surface application.

Seasonal high water table. Spring rains (March through June) and fall rains (September through November) can saturate soils and push water tables up. Systems must maintain proper separation from groundwater even during wet seasons, which often requires curtain drains or mound construction ($1,500-$3,000 additional).

Rock excavation costs: Cutting through limestone for tank placement and trenches typically adds $2,000-$4,000 to the project. Contractors unfamiliar with Hill Country conditions sometimes underestimate this.

How Do Edwards Aquifer Rules Affect Septic Systems in Kendall County?

Portions of Kendall County, including areas around Boerne, sit within the Edwards Aquifer recharge zone. Properties in these zones need separate TCEQ approval on top of the county permit.

The Edwards Aquifer supplies drinking water to roughly 2 million Central Texas residents. Because it's a karst aquifer (fractured limestone with caves and sinkholes), surface pollution can reach groundwater rapidly. As Susan Parten, PE, notes in her study published through the Hill Country Alliance, aquifer species are "quite vulnerable to even very low concentrations of contaminants from wastewater," which is why TCEQ imposes extra requirements through the Edwards Aquifer Protection Program (30 TAC Chapter 213).

What this means for homeowners:

• Dual permitting. Your septic plans need approval from both Kendall County and TCEQ's Edwards Aquifer Protection Program. TCEQ's administrative review can take up to 30 days, and technical review can extend to 90 days for complete applications.

• Enhanced system requirements. Properties in the recharge zone may face restrictions on conventional disposal and require enhanced treatment before wastewater reaches the ground.

• Additional design requirements. Site-specific geologic assessments, enhanced stormwater management, and best management practices may be required.

• Cost impact. Edwards Aquifer requirements can add $2,000-$5,000 to your total project cost through additional design work, enhanced system requirements, and longer timelines.

Check your property: Use the TCEQ Edwards Aquifer interactive map at tceq.texas.gov/gis/edwards-viewer.html to see if your property falls within a protection zone. You can also contact the TCEQ San Antonio Regional Office at (210) 490-3096.

What Are the Aerobic System Requirements in Kendall County?

Aerobic septic systems in Kendall County require a two-year initial maintenance contract, quarterly service visits, and reports filed to the county at least every 4 months. Annual maintenance runs $600-$900.

Given that most Kendall County properties end up with aerobic systems, this section matters for the majority of homeowners.

The Affidavit to the Public: Before your permit is issued, you must sign a notarized affidavit committing to ongoing maintenance. This is recorded at the Kendall County Clerk's office and becomes part of the public record tied to your property deed. Future buyers will see this obligation.

Initial maintenance: Your installer covers the first two years of maintenance. After that, you're responsible for keeping a maintenance contract active for the life of the system.

Quarterly service visits. Your licensed maintenance provider must visit at least every 3 months (4 times per year). Each visit includes checking:

• Control panel and electrical circuits
• Aeration system (compressor, diffusers, air flow)
• Pump operation
• Sludge levels
• Disinfection unit
• General system condition

The provider marks an identification tag at each visit to document service history.

Reporting schedule: Reports go to both Kendall County and you at least every 4 months. If your system has electronic monitoring, reporting can drop to every 6 months.

Budget $600-$900 per year for aerobic maintenance in the Boerne area. That's higher than conventional system pumping ($300-$500 every 3-5 years), but aerobic maintenance prevents the drain field failures that are common in Hill Country soils. As Dr. Anish Jantrania, Extension Specialist at Texas A&M AgriLife, notes in the Texas Groundwater Protection Committee FAQ, malfunction of a septic system "can lead to wastewater backing up into the home or surfacing of untreated effluent, both of which lead to public health concerns and environmental problems."

What Happens If You Violate Kendall County Septic Rules?

Kendall County takes septic violations seriously. Unpermitted work triggers double fees, and the county can file a Certificate of Non-Compliance on your property deed.

What triggers enforcement:

• Installing or repairing a system without a permit
• Failing to maintain an aerobic system contract
• Systems causing surface discharge or odors
• Failing required inspections
• Falsifying information on permit applications

The enforcement process: When the county identifies a violation, you receive written notice describing the problem and required corrections. You'll have a specified deadline to fix the issue.

Penalties under Texas law:

• First offense: Class C misdemeanor, fine of $50-$200
• Subsequent offense: Fine of $200-$1,000, possible jail up to 6 months
• Non-compliance fee: Double the standard permit fee for unpermitted work
• TCEQ civil penalties for serious violations: Up to $5,000 per day

Certificate of Non-Compliance: If violations continue after notice, Kendall County can file a Certificate of Non-Compliance in the real property records. This creates a public record tied to your deed that can complicate property sales, refinancing, and transfers. It's a powerful enforcement tool that gives the county real leverage.

Permit revocation: If the county finds false information in your application, or you violate county ordinances, your permit can be revoked. You'd need to start over with a new application and new fees.

How Much Does Septic Work Cost in Kendall County?

A conventional septic system in Kendall County runs $9,000-$16,000 installed, while aerobic systems cost $15,000-$25,000+. Hill Country geology adds $2,000-$7,000 in site-specific costs that you won't see in flatter parts of Texas.

Here's what homeowners in the Boerne area should budget:

Item	Cost Range
Conventional system install (where soil allows)	$9,000-$16,000
Aerobic system install	$15,000-$25,000+
Low-pressure dose system	$12,000-$18,000
Mound system (engineered)	$25,000-$30,000+
Site evaluation and soil testing	$800-$1,500
System design (sanitarian)	$1,200-$2,500
System design (PE, required for aerobic)	$2,500-$5,000
County permit fee (residential)	$340
Rock excavation (limestone)	$2,000-$4,000
Slope terracing	$1,000-$2,500
High water table management	$1,500-$3,000
Septic pumping (1,000-gallon tank)	$300-$450
Aerobic maintenance contract (annual)	$600-$900
Drain field replacement	$6,000-$15,000

Kendall County costs run significantly higher than most Texas counties because of the geology. The limestone, slopes, and limited soil depth force more expensive system types and add rock excavation costs. For comparison, a conventional system in Central Texas flatland might run $6,000-$10,000 installed, while the same home in Kendall County could require a $15,000-$25,000 aerobic system plus $2,000-$4,000 in rock excavation. Expect your total project to come in 30-50% higher than it would on flat land with good soil.

For a full breakdown of Texas septic costs, see our septic pumping cost guide.

Frequently Asked Questions

Do I need a permit for septic work in Kendall County?

Yes, all new installations, repairs, tank replacements, and modifications require a permit from the Kendall County Environmental Health Department. The 10-acre exemption applies under strict conditions, but the county has increased audits of claimed exemptions. Routine pumping does not require a permit.

How much does a septic permit cost in Kendall County?

A new residential septic permit costs $340, but total pre-installation costs run $2,340-$6,840 including soil evaluation and system design. Budget $800-$1,500 for soil evaluation, $1,200-$5,000 for system design (depending on whether a sanitarian or PE designs it), and the $340 permit.

Why are septic systems so expensive in Kendall County?

Hill Country limestone forces most properties into aerobic systems at $15,000-$25,000+, compared to $9,000-$16,000 for conventional systems in areas with better soil. Roughly 60% of properties hit bedrock within 18-24 inches, ruling out conventional designs. Rock excavation adds $2,000-$4,000, and steep slopes or high water tables add more. The same system that costs $8,000 in Central Texas flatland can easily hit $20,000+ in Kendall County.

Does the Edwards Aquifer affect my septic system in Kendall County?

It can, if your property is in the recharge zone. Portions of Kendall County around Boerne are in the Edwards Aquifer recharge, transition, or contributing zones. Properties in these areas need separate TCEQ approval through the Edwards Aquifer Protection Program, which can add 30-90 days to your timeline and $2,000-$5,000 to costs. Check the TCEQ Edwards Aquifer map viewer to see if your property is affected.

How often does my aerobic system need maintenance in Kendall County?

Every 3 months (quarterly visits), with reports filed every 4 months. Your installer covers the first two years. After that, you must maintain a contract with a licensed provider for the life of the system. Budget $600-$900 per year. The maintenance obligation is recorded on your property deed through a notarized affidavit.

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Last updated: February 7, 2026 Reviewed by: Texas Septic Guide Editorial Team, content verified against TCEQ regulations, Kendall County development regulations, Edwards Aquifer Protection Program (30 TAC Chapter 213), and 30 TAC Chapter 285

Need septic help in Kendall County? Get free quotes from vetted local providers

Sources: Kendall County Environmental Health Department; Kendall County Development Regulations; Texas Commission on Environmental Quality (TCEQ), 30 TAC Chapter 285; TCEQ Edwards Aquifer Protection Program, 30 TAC Chapter 213; Cow Creek Groundwater Conservation District; Texas Health and Safety Code Chapter 366.

Serving Kendall County communities: Boerne