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

Hays County requires septic permits for all properties with no 10-acre exemption. Edwards Aquifer zone properties must install aerobic systems with two-year maintenance contracts.

Hays County is one of the fastest-growing counties in Texas. According to U.S. Census Bureau estimates, the county's population reached roughly 312,000 in 2026, nearly double its 2010 count of 158,086. Cities like Kyle, Buda, and San Marcos have exploded over the past decade, and new construction in unincorporated areas keeps pushing into Hill Country terrain with shallow soils and karst limestone. That growth means more septic systems going into sensitive ground, and the county has responded with strict permitting requirements.

If you live in unincorporated Hays County with a septic system, the rules here have some notable differences from other Texas counties. The biggest: there's no 10-acre exemption. Every property needs a permit. This guide covers the full picture, from permits and fees through aerobic requirements and enforcement.

Key Requirement	Hays County Rule
10-acre exemption?	No. All properties need permits.
Permitting authority	Hays County Development Services (TCEQ authorized agent)
Permit application	Online only, via MyGovernmentOnline
Permit cost	$400-$700 (plus $600-$1,200 site evaluation)
Aerobic system required?	Yes, in Edwards Aquifer Recharge Zone
Maintenance contract	2-year initial + ongoing for aerobic systems
Cluster systems	Prohibited
Penalties	Class C misdemeanor for willful violations

Who Handles Septic Permits in Hays County?

Hays County Development Services issues all septic permits in unincorporated areas of the county, acting as an authorized agent of TCEQ.

Per the Hays County Rules of On-Site Sewage Facilities, the county administers its septic program by adopting TCEQ's 30 TAC Chapter 285 and 30 TAC Chapter 30 (Subchapters A and G). The county operates as a TCEQ authorized agent under Texas Health and Safety Code Chapter 366, giving it authority over the location, design, construction, installation, and operation of septic systems.

One thing to note: these rules only apply to unincorporated Hays County. If your property is within the city limits of San Marcos, Kyle, Buda, Dripping Springs, or Wimberley, check with that city's permitting office first. Some incorporated areas handle their own septic permits.

Contact information:

Detail	Information
Office	Hays County Development Services
Phone	(512) 393-2150
Complaints	(512) 393-2150, option 3
Online portal	hayscountytx.gov/septic-permits
Application system	MyGovernmentOnline

All permit applications go through the MyGovernmentOnline platform. You'll need to create an online account and submit documents digitally. Paper applications are not accepted. The county's Documents and Forms page has the full application packet, including the site plan template and checklists.

What Are the Permit Types and Fees in Hays County?

Septic permits in Hays County cover new installations, repairs, and modifications, with fees varying by system type. Budget $400-$700 for the permit alone, with total costs including site evaluation running $1,000-$1,900.

Here's what to expect for common permit types:

Permit Type	Estimated Fee	Notes
New residential septic install	$400-$700	Varies by system complexity
Repair/modification	$300-$500	Must reference original permit
Commercial/institutional	$500+	Higher review fees apply
Site evaluation and soil testing	$600-$1,200	Professional engineer required

Exact fees are listed on the Hays County Fee Schedule, available for download on the Development Services website or at their office. Fees change periodically, so check the current schedule before budgeting.

No 10-acre exemption in Hays County. This is the biggest difference from many other Texas counties. Under standard TCEQ rules, properties of 10 acres or larger with a single home and proper setbacks may be exempt from local permitting. Hays County has eliminated this exemption. Every property with a septic system needs a permit, no matter how big the lot is. This applies to new installations, repairs, and modifications.

How Does the Hays County Septic Permit Process Work?

The permit process runs through MyGovernmentOnline, with administrative review taking several business days followed by technical review and authorization to construct.

Here's the step-by-step process:

1. Site evaluation. Hire a Professional Engineer (PE) or Licensed Professional Sanitarian to evaluate your soil conditions, run percolation tests, and design the system. In the Hill Country portions of Hays County, rocky shallow soils often push designs toward aerobic or drip irrigation systems.

2. Gather documents. You'll need: the septic system application form, site plan and system design, location map, floor plan of the home, and your TCAD tax account summary. For aerobic or advanced treatment systems, also include a Maintenance Affidavit and a two-year initial maintenance contract.

3. Submit application online. Create an account on MyGovernmentOnline and upload all documents with your application fee. Paper applications are not accepted.

4. Administrative review. Hays County Development Services reviews your application for completeness. This takes several business days. Incomplete applications get returned.

5. Technical review. An inspector reviews the technical details of your system design against the Hays County Rules of On-Site Sewage Facilities and 30 TAC Chapter 285.

6. Authorization to construct. Once approved, you receive authorization to begin installation. Only a TCEQ-licensed installer can do the work.

7. Inspections. The county inspector checks the installation at required stages. No components can be covered or buried until the inspector approves them.

8. Notice of Approval (permit). After the system passes final inspection, you receive the Notice of Approval, which is your official permit to operate.

The county can deny permits for properties that violate Hays County Development (Subdivision) Regulations, even if the septic system design itself is compliant.

What Rules Does Hays County Add Beyond State Minimums?

Hays County imposes stricter rules than base TCEQ standards, including no 10-acre exemption, mandatory maintenance contracts for aerobic systems, and prohibition of cluster systems.

These are the key differences between Hays County and what you'd face in many other Texas counties:

No 10-acre exemption. Worth repeating because it catches people off guard. In most Texas counties, large-lot homeowners can skip the local permit process. Not here. Hays County requires permits for all septic systems, period.

Cluster systems prohibited. Shared septic systems serving multiple properties (cluster systems under Section 285.6) are not authorized in Hays County. Each property needs its own system.

Mandatory ongoing maintenance for advanced systems. Aerobic and other advanced treatment systems require ongoing maintenance contracts for the life of the system, not just during the initial period.

Setback requirements:

Feature	Minimum Distance
Property lines (effluent dispersal areas)	20 feet
Water wells (sewer pipe with watertight joints)	20 feet
Water wells (tanks)	50 feet
Public water wells (effluent dispersal areas)	150 feet

Drip irrigation dispersal areas with percolation rates of 0.1 or less may qualify for reduced setbacks. Check with Development Services for specifics.

Edwards Aquifer Recharge Zone: Significant portions of western Hays County, including areas around Dripping Springs and Wimberley, sit within the Edwards Aquifer Recharge Zone. According to TCEQ's Edwards Aquifer Protection Program, properties in these areas typically can't install conventional systems and must use aerobic treatment or engineered alternatives. TCEQ's 30 TAC Chapter 213 (Edwards Aquifer rules) applies on top of the county's own requirements. As Texas A&M AgriLife Extension water resources specialists note in their OSSF guidance (Publication B-6077), all on-site sewage facilities in the Edwards Aquifer recharge zone face heightened requirements to prevent groundwater contamination.

What Are the Aerobic System Requirements in Hays County?

Aerobic septic systems in Hays County require a two-year initial maintenance contract submitted with the permit application, plus ongoing maintenance for the life of the system.

Given the Hill Country terrain and Edwards Aquifer protections, a large share of Hays County properties end up with aerobic systems. Here's what the county expects:

Two-year initial maintenance contract is mandatory. When you apply for your permit, you must include a signed maintenance contract with a TCEQ-licensed provider covering the first two years of system operation. You also need to submit a Maintenance Affidavit.

Ongoing maintenance after two years. Hays County requires ongoing maintenance for all aerobic and advanced treatment systems. After the initial two years, you may be able to maintain your own system. Hays County and the Plum Creek Watershed Partnership have offered online training courses for homeowners who want to handle their own aerobic system maintenance.

Inspection and reporting. Under TCEQ rules enforced locally, maintenance providers must inspect aerobic systems every 3-4 months and file reports with the county. Reports cover system operation, component condition, effluent quality, and any needed repairs.

What the maintenance provider checks:

• Aerator and blower operation
• Alarm system function
• Disinfection unit (chlorine or UV)
• Spray heads or drip emitters
• Effluent quality
• General system condition

Budget $500-$700 every two years for a standard aerobic maintenance contract in the Hays County area.

What Happens If You Violate Hays County Septic Rules?

Hays County enforces septic violations through its Development Services office. Under Texas Health and Safety Code Chapter 366, willful violations are Class C misdemeanors.

The enforcement process in Hays County follows the standard Texas framework:

What triggers enforcement:

• Operating without a permit (remember: no 10-acre exemption)
• Installing or modifying a system without authorization
• Failing to maintain an aerobic system contract
• Systems causing surface sewage, odors, or contamination
• Failing required inspections

How to file a complaint: Call (512) 393-2150 (option 3), email, or submit through the county's web portal.

Penalties: Under Texas Health and Safety Code Chapter 366, willful septic violations are Class C misdemeanors. TCEQ can pursue civil penalties for serious or ongoing violations. Because Hays County has no 10-acre exemption, homeowners on large lots who assumed they didn't need permits are sometimes caught off guard during enforcement sweeps or real estate transactions.

Unpermitted work: All installation, repair, and modification work requires a permit and a TCEQ-licensed installer. Homeowners can perform basic maintenance on their own conventional system. For aerobic systems, self-maintenance may be possible after completing an approved training course.

How Much Does Septic Work Cost in Hays County?

A conventional septic system in Hays County runs $6,300-$7,500 installed for a 3-bedroom home, while aerobic systems cost $7,800-$20,000. Add $1,000-$1,900 for permits and site evaluation.

Here's what homeowners in the San Marcos, Kyle, and Buda area should budget:

Item	Cost Range
Conventional system install (3-bedroom)	$6,300-$7,500
Aerobic spray system	$7,800-$9,800
Aerobic drip system	$9,800-$12,000
Site evaluation and soil testing	$600-$1,200
County permit fee	$400-$700
Septic pumping (1,000-gallon tank)	$235-$276
Aerobic maintenance contract (2 years)	$500-$700
Typical repair (per hour + materials)	$275-$375/hour
Drain field replacement	$3,000-$7,000

Costs in the Hill Country portions of Hays County (Dripping Springs, Wimberley) tend to run higher than the I-35 corridor (Kyle, Buda, San Marcos).

Cost Factor	I-35 Corridor (Kyle, Buda, San Marcos)	Hill Country (Dripping Springs, Wimberley)
Most common system type	Conventional	Aerobic (spray or drip)
Typical install cost	$6,300-$7,500	$7,800-$12,000+
Edwards Aquifer zone?	Rarely	Often
Extra permit requirements	Standard TCEQ	TCEQ + Edwards Aquifer rules (30 TAC 213)

Rocky soils and Edwards Aquifer requirements push many properties toward aerobic systems, which cost $2,000-$10,000 more than conventional. If you're building in western Hays County, plan for aerobic system pricing from the start.

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 Hays County?

Yes, always. Hays County requires permits for all septic systems regardless of lot size. There is no 10-acre exemption in Hays County, unlike many other Texas counties. New installations, repairs, and modifications all need a permit through the MyGovernmentOnline system. Routine pumping does not require a permit.

How much does a septic permit cost in Hays County?

Budget $400-$700 for the permit alone. Exact fees depend on system type and complexity. Check the current Hays County Fee Schedule on the Development Services website. Add $600-$1,200 for the required site evaluation and soil testing. Your licensed installer often handles the permit application as part of their service.

Who inspects septic systems in Hays County?

Hays County Development Services inspectors handle all septic inspections. Your licensed installer coordinates inspection appointments with the county. The inspector must approve the installation at each required checkpoint before components can be covered. For aerobic systems, your maintenance provider handles ongoing inspections and files reports with the county every 3-4 months.

Can I do my own septic work in Hays County?

Installation and repairs must be done by a TCEQ-licensed installer. For conventional systems, homeowners can perform basic maintenance on their own single-family home's system. For aerobic systems, you can take over maintenance after the initial two-year professional contract ends. Hays County and the Plum Creek Watershed Partnership have offered online training courses to help homeowners learn proper aerobic system maintenance.

Why doesn't Hays County have a 10-acre exemption like other Texas counties?

Hays County eliminated the 10-acre exemption to protect groundwater in one of Texas's fastest-growing regions. Large portions of the county sit on the Edwards Aquifer Recharge Zone and Trinity Aquifer, where improperly designed or maintained septic systems can contaminate drinking water. By requiring permits for all properties, the county can verify that every system meets design standards and that aerobic systems in sensitive areas have proper maintenance contracts. If you're buying rural land in Hays County, factor in the permitting cost and timeline from day one.

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Last updated: February 7, 2026 Reviewed by: Texas Septic Guide Editorial Team, content verified against TCEQ regulations, Hays County Rules of On-Site Sewage Facilities, and 30 TAC Chapter 285

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Sources: Hays County Development Services; Hays County Rules of On-Site Sewage Facilities; Texas Commission on Environmental Quality (TCEQ), 30 TAC Chapter 285; Texas Health and Safety Code Chapter 366; TCEQ Edwards Aquifer Protection Program, 30 TAC Chapter 213; U.S. Census Bureau Population Estimates; Texas A&M AgriLife Extension OSSF Program (Publication B-6077).

Serving Hays County communities: San Marcos | Kyle | Buda | Dripping Springs | New Braunfels