Septic in Navarro County, TX

Last updated: Mar 21, 2026

If you've driven around Navarro County, you've probably noticed a mix of well-kept yards, big oaks, and the occasional visible septic drain field—because in many parts of the county, wastewater isn't sent to a city sewer. Welcome to your Navarro County septic guide, where practical, neighborly advice comes with a hands-on experience you can trust.

Is septic common in Navarro County? Should I expect septic if I own or buy a home?

  • Yes. Outside the city limits, most single-family homes rely on septic systems.
  • If a home has a yard, a well for water, and isn't hooked to a municipal sewer line, chances are there's a septic system in place.
  • When you're buying, ask for septic specific details: past pumping records, maintenance history, and the seller's disclosure. A quick inspection can save surprises later.

Why homes typically use septic systems here

  • Rural and semi-rural layout: Large lots and dispersed development made centralized sewer easier to extend in the city, but many Navarro County neighborhoods and farms sit far enough from town lines that on-site systems are the practical option.
  • Cost and feasibility: Extending sewer mains across farmland and rolling terrain can be expensive and slow. Septic offers a reliable, on-site solution that fits local land and water use.
  • Groundwater and wells: Many homes rely on private wells and use septic to keep wastewater separate from drinking water sources, aligning with sensible, site-specific design.

County growth history and how that has impacted septic coverage

  • Navarro County has long roots in farming, small-town life, and later oil activity around Corsicana, with growth pattern concentrated along highways and town corridors.
  • In recent decades, steady population increases and new subdivisions spilling outward from Corsicana and surrounding towns have increased the number of homes not served by centralized sewer systems.
  • As the county has grown, so has the need for well-designed, well-maintained septic systems. The mix of aging systems and new installations means homeowners are more likely to encounter different maintenance schedules, replacement timelines, and inspection requirements.

High-level explanation (why septic exists here)

  • On-site wastewater treatment is a practical, land-based solution that works with Navarro County's mix of rural lots, soil types, and existing water wells. It allows homes to function safely where municipal sewer isn't readily available or cost-effective.

Think of this page as a friendly, local starting point. I'm here as your neighbor and a licensed septic professional to help you navigate inspections, maintenance, and the basics of keeping your system reliable.

How Septic Is Regulated in Navarro County

The State Regulator: TCEQ's On-Site Sewage Facility (OSSF) Program

  • The Texas Commission on Environmental Quality (TCEQ) is the primary state regulator for OSSFs. They set the design and performance standards, permit requirements, and enforcement rules that govern septic systems statewide.
  • OSSFs include conventional septic tanks, drain fields, and any approved alternative systems. Homeowners must meet the applicable rules in Texas Administrative Code for OSSFs.
  • Design plans, system modifications, and new installations typically require review and approval to ensure soil, groundwater, and setback considerations are met.
  • Licensed professionals (designers/installers) work under TCEQ regulations; verification of current licenses is advisable.
  • Official resource: Texas Commission on Environmental Quality — On-Site Sewage Facility Program:

Local Oversight in Navarro County

  • Navarro County Health Department coordinates with the state program to review plans, issue permits, and inspect OSSFs within the county.
  • Local records (permits, inspection results) are maintained by the county; they may require additional forms or fees beyond state requirements.
  • If you live inside a city within Navarro County, the city's environmental health or building department may impose extra local permits or requirements—check with your city office.
  • For unincorporated areas, Navarro County Health Department is typically your primary contact.
  • Official local resource: Navarro County Government (general site): https://www.co.navarro.tx.us/

Do I Need a Permit? How to Apply (Steps)

  1. Confirm jurisdiction: determine whether your property falls under unincorporated Navarro County or a city within the county to know which permit path applies.
  2. Hire licensed professionals: engage an OSSF designer licensed in Texas to prepare plans; hire a licensed OSSF installer to perform the work.
  3. Prepare the design package: include site evaluation, soil data, tank size, drain field layout, setback distances, and any required drainage or utility details.
  4. Submit for review: take plans and supporting documents to the Navarro County Health Department (and your city if required); pay any applicable fees.
  5. Plan review and permit: wait for approval to proceed; you will receive a permit to install the system (some projects may require additional state clearance).
  6. Install and inspect: schedule required inspections during construction; a final inspection yields authorization to operate.
  7. Recordkeeping: keep all permits, inspection reports, maintenance schedules, and pumping records; these may be needed for property transactions or if the system is ever evaluated by the county.

Licensing and What to Verify

  • Ensure designers, installers, and service providers hold current Texas OSSF licenses or registrations.
  • Confirm license numbers and expiration dates; request references or project examples if helpful.
  • Record the contact information for your service provider for routine maintenance reminders.

Ongoing Maintenance and Compliance

  • Follow recommended pumping intervals (often every 3–5 years, but follow your system's specific guidance).
  • Use only approved products in the system and dispose of fats, oils, greases, solvents, or non-biodegradable materials away from the septic system.
  • Keep the drain field area clear of heavy vehicles, deep-rooted trees, and construction activity.
  • Retain maintenance records (pumping receipts, inspection notes) since they can be requested during property sale or county inspections.

Learn More and Confirm Details

Soil, Groundwater & Environmental Factors in Navarro County

Local soils and how they affect septic systems

Navarro County soils range from sandy loams to heavier clays, and soil texture plus structure greatly influence how wastewater is absorbed and treated. Percolation tests help gauge whether the soil will drain quickly enough for a drainfield to function or if a more elevated design is needed. In soils with slow permeability, restrictive layers, or shallow depth to bedrock, a conventional drainfield may underperform. An alternative such as a mound system or other design may be appropriate. To preview soil properties on your property, consult the NRCS Web Soil Survey to identify your soil map units and their drainage class, depth to groundwater, and other factors:

  • NRCS Web Soil Survey:

    • Typical Septic System Types in Navarro County

    Conventional gravity septic systems

    • How it works: Wastewater flows from the house into a septic tank, then by gravity into a perforated drainfield (usually trenches filled with gravel or chamber media).
    • When it's a good fit: Suitable soils with adequate depth to the water table and good percolation.
    • Pros: Simple design, lower upfront cost, durable when soils are right.
    • Cons: Requires properly drained soil and a sizable drainfield; performance undermined by heavy groundwater, compacted zones, or poor soil.
    • Maintenance basics: Regular pumping every 2–3 years (or more often with high daily use); keep trees, vehicles, and heavy loads off the drainfield area.

    Chamber and bed systems

    • How it works: Plastic chambers or modular beds replace some gravel in the drainfield, expanding usable area without heavy trench excavation.
    • When it's a good fit: Narrow lots or sites where conventional drainfields are hard to fit; soils that need more surface area to infiltrate effluent.
    • Pros: Easier installation in limited space; can be more adaptable to slope and site constraints.
    • Cons: Still soil-dependent; need proper configuration and cover to protect from compaction.
    • Maintenance basics: Similar to conventional systems—inspect, avoid parking or digging over the field, and have the system pumped as recommended.

    Mound systems

    • How it works: A raised, engineered drainfield built above the native soil on a sand-soil mixture; a pressure or gravity distribution system sends effluent into the mound.
    • When it's a good fit: Shallow soils, high groundwater, or poor native soil where a traditional drainfield won't function.
    • Pros: Allows septic treatment where soil conditions would otherwise prevent disposal.
    • Cons: Higher installation cost; requires space and proper design; routine maintenance by a licensed installer.
    • Maintenance basics: Regular professional inspections; protect the mound from compaction, landscaping changes, and heavy use.

    Aerobic Treatment Units (ATUs) and other advanced options

    • How it works: ATUs introduce oxygen to the treatment chamber, producing a higher level of wastewater treatment before it reaches the drainfield.
    • When it's a good fit: Sites with restrictive soils, high-strength wastewater, or limited drainfield area; can reduce the size of the final disposal field.
    • Pros: Higher quality effluent, potential for smaller or alternative disposal layouts; robust performance in challenging soils.
    • Cons: Requires electricity and regular servicing by an approved provider; higher ongoing maintenance costs.
    • Maintenance basics: Routine service checks (often monthly or quarterly) and annual professional inspections; keep venting and electrical components clear.

    Maintenance basics you'll hear about in Navarro County

    1. Schedule and document pumping every 2–3 years for typical systems; more frequent pumping may be needed with higher usage.
    2. Have a licensed professional perform annual or semiannual inspections; follow local requirements and TCEQ guidance.
    3. Protect the drainfield zone: no vehicles, landscaping, or deep-rooted plants on or over the drainfield.
    4. Conserve water and avoid flushing non-biodegradable items, solvents, or chemicals that can harm treatment processes.
    5. Keep good records: system layout, pump dates, repairs, and any soil or effluent concerns.

    Official guidance and resources

    Typical Septic Issues Across Navarro County

    Common signs your Navarro County system is telling you something's wrong

    • Frequent toilet or drain backups and slow drains throughout the house.
    • Gurgling sounds in pipes after flushing or running water.
    • Foul odors near fixtures, vents, or the septic area.
    • Standing water or soggy, unusually green patches over the drain field or absorption area.
    • Remedy attempts like excessive pumping without improvement.
    • Puddling or wet spots above or around the septic tank or drain field.

    Regional factors that influence septic performance in Navarro County

    • Clay soils and high clay content can slow drainage and hamper drain-field performance.
    • Heavy rainfall and groundwater fluctuations can saturate the drain field, leading to backups.
    • Tree roots near underground lines can invade and damage pipes.
    • Older systems near aging neighborhoods may be nearing end-of-life and need evaluation or replacement.
    • Common household practices (garbage disposals, large laundry loads, and high water use) stress systems sooner.

    Quick, practical steps if you suspect a problem

    1. Minimize water use to reduce load on the septic system until inspected.
    2. Avoid driving or placing heavy loads over the drain field and keep pets and kids off the area.
    3. Locate the septic tank lid and access points, but do not opener attempt without proper training.
    4. Call a licensed septic professional in Navarro County for a pump inspection and diagnostic.
    5. If you notice sewage surfacing, strong odors, or environmental risk, contact the Navarro County Health Department for guidance.

    Maintenance and prevention to reduce issues

    • Schedule pumping based on tank size and household usage (typical household service every 3–5 years; more people or a larger tank may require earlier pumping).
    • Use water-saving fixtures and distribute laundry over several days to avoid peaks.
    • Think twice before flushing wipes, diapers, grease, solvents, or chemicals; only human waste and toilet paper should go into the system.
    • Keep the drain field protected: avoid parking vehicles or heavy equipment on the area; plant only shallow-rooted, non-invasive vegetation at a safe distance.
    • Use septic-safe household products and avoid introducing large quantities of fats or chemicals that kill beneficial bacteria.
    • Do not rely on aftermarket additives; they are not a substitute for proper pumping and maintenance.

    When to call for professional evaluation or replacement

    • The system is older (often 20–30+ years) and shows repeated failures after pumping.
    • The drain field shows persistent wet spots, odors, or surface surfacing despite maintenance.
    • There is backflow into the home after a pumping or if the system has structural damage.
    • Local health department guidance indicates issues that may require upgrades or replacement to meet code.

    Official resources

    • Texas Commission on Environmental Quality (TCEQ) – Onsite Sewage Treatment Systems:
    • U.S. Environmental Protection Agency (EPA) – Septic Systems: https://www.epa.gov/septic

    Septic Inspection, Permits & Local Oversight

    Permitting and Oversight in Navarro County

    In Texas, OSSFs are governed by state rules, but Navarro County handles local administration under those rules. The Texas Commission on Environmental Quality (TCEQ) sets statewide requirements for design, permitting, installation, operation, and maintenance of on-site septic systems. Navarro County Health Department administers the local OSSF program, processes permit applications, conducts inspections, and maintains records for the county.

    • When you need a permit: For new systems, replacements, substantial repairs, system relocations, or changes in usage that affect the system, a permit is typically required before work begins.
    • Where to start: Contact Navarro County Health Department's Environmental Health team to confirm permit needs, submit plans, and schedule inspections. Official county site:
    • What you'll submit: A site plan showing tank locations and leach field layout, a soils/percolation evaluation by a qualified professional, and system design documentation from an OSSF designer/installer.
    • Timelines and costs: Review and permit issuance timelines vary by project size and workload. Permit fees are set by the county per TCEQ guidelines.
    • Local flexibility: Some municipalities within Navarro County may have additional requirements or local amendments. Always check with the county office early.

    Step-by-Step: Getting a Permit

    1. Determine permit needs by checking with Navarro County Health Department or the TCEQ.
    2. Hire a licensed OSSF designer/installer to prepare plans and soil evaluations.
    3. Prepare required documents: site plan, soils report, and system design documentation.
    4. Submit the permit application and fees to Navarro County Health Department.
    5. Await review; respond to any requested changes or additional information.
    6. Once approved, receive the permit, schedule inspections, and complete installation with a final inspection for an approved as-built.

    Inspections & Maintenance

    • Pre-construction evaluation: A qualified professional should assess soil suitability and site constraints before design work begins.
    • Installation inspections: Local inspectors verify tank placement, trenching, backfill, and component installation during construction.
    • Final inspection and as-built: An as-built drawing is often required to verify the as-installed system matches the approved plan.
    • Ongoing maintenance: Homeowners should follow the maintenance schedule specified by the designer/installer and local requirements. Regular pumping (typically every 3–5 years for a standard residential system) and keeping records are essential. Protect the drainfield from driving or heavy equipment, and avoid dumping chemicals, grease, or non-biodegradable materials into the system.
    • Local operating permits: Some Navarro County OSSFs require periodic inspections or an annual operating permit. Check with the county to confirm any ongoing oversight requirements.

    Local Oversight: Roles and Contacts

    • County role: Navarro County Health Department administers the permit process, inspections, and record-keeping for OSSFs under state rules.
    • State role: TCEQ provides the overarching regulations and guidance for all OSSFs in Texas.
    • How to reach them: For permit questions, inspections, and records, contact Navarro County Health Department through the county's official site or the Environmental Health page.

    Resources

    • TCEQ On-Site Sewage Facilities (OSSF) program: (Title 30, Part 1, Chapter 285)

    Cost Expectations for Septic Services in Navarro County

    Septic Tank Pumping and Cleaning

    Regular pumping removes accumulated sludge and prevents backups. Navarro County's clay-heavy soils can influence how quickly tanks fill and how accessible the tank is, especially on older properties.

    • What's included: pump out the tank, clean around the lids, inspect inlet/outlet baffles, measure sludge and scum levels, check for leaks or alarms, and note when the next pumping is advised.
    • Typical cost in Navarro County: roughly $200-$450 for a standard 1,000-gallon tank; $350-$650 for larger tanks or difficult-to-access sites.
    • Navarro-specific notes: plan for travel or equipment-access fees on remote properties; combining pumping with an inspection can save trips.

    Septic System Inspection (Residential/Real Estate)

    Inspections are essential for buying a home or keeping on track with maintenance. Local soils and older tank designs in Navarro County can affect findings.

    • What's included: visual inspection of lids and components, odor checks, pump and float verification, field inspection, and a concrete plan for the next 2–5 years; camera inspection if needed.
    • Typical cost in Navarro County: basic inspection $150-$300; with a camera or detailed report $350-$500.
    • Navarro-specific notes: if the system is older or lacks accessible risers, expect a more thorough inspection and possible recommendations for upgrades.

    New Septic System Installation

    Costs vary widely with soil conditions and system type. Navarro County's clay soils and potential mound requirements can drive prices higher than ideal soil sites.

    • What's included: site evaluation, percolation tests, system design, permits, tank and field installation, startup and pass-through testing.
    • Typical cost in Navarro County: ballpark $7,000-$18,000 for conventional gravity systems; $15,000-$25,000+ for mound or advanced distribution systems.
    • Navarro-specific notes: lot size, slope, and soil tests strongly impact final price; expect a longer permitting timeline if environmental health review is required.

    Drain Field Repair/Replacement

    A failing drain field is common in older Navarro properties; root intrusion and soil compaction can necessitate rehab or replacement.

    • What's included: diagnosis of failed absorption area, soil tests, field modifications, trench or bed repairs, possible upsizing of lines, and system re-start.
    • Typical cost in Navarro County: repair $3,000-$10,000; replacement $10,000-$25,000+ depending on size and access.
    • Navarro-specific notes: availability of replacement soil beds and mound options may influence cost; proximity to trees and roots often raises prices.

    Drain Line Jetting/Cleaning

    Used to clear stubborn clogs or buildup that impede effluent flow; not a cure-all for a failing system.

    • What's included: high-pressure jetting of lines from tank to field, sometimes camera inspection afterward.
    • Typical cost in Navarro County: $300-$600 per service, depending on line length and access.
    • Navarro-specific notes: frequent in homes with tree roots or long, buried lines; budget for additional camera inspection if problem persists.

    Tank Baffle Repair/Replacement

    Damaged baffles allow sludge to slip into the drain field, speeding field failure.

    • What's included: assessment of damaged baffles, replacement with PVC or epoxy options, resealing and testing.
    • Typical cost in Navarro County: $350-$1,200 depending on material and tank access.
    • Navarro-specific notes: older concrete tanks may require more extensive work or partial rebuildups.

    Tank Risers, Lids, and Accessibility Improvements

    Risers improve access for routine maintenance and inspections.

    • What's included: installation of concrete or plastic risers, new lids, and secure sealing.
    • Typical cost in Navarro County: $500-$1,500 for parts plus labor.
    • Navarro-specific notes: improving accessibility can reduce future service costs and simplify inspections.

    Camera Inspection of Drainage Lines

    In-depth evaluation helps pinpoint root intrusion, cracks, or sags.

    • What's included: video crawl of lines from the tank outlet through the field to identify trouble spots.
    • Typical cost in Navarro County: $100-$300 for basic inspection; $300-$500 for a full diagnostic with report.
    • Navarro-specific notes: recommended when symptoms persist after pumping or unusual odors are present.

    Maintenance Plans and Service Contracts

    Regular care helps prevent big failures and provides predictable budgeting.

    • What's included: scheduled pumping, annual inspections, priority scheduling, and reduced rates for additional visits.
    • Typical cost in Navarro County: $150-$300 per year for basic plans; some providers offer monthly options in the $15-$25 range.
    • Navarro-specific notes: bundling pumping with inspections often yields the best value.

    Holding Tanks (Residential/Small Business)

    Some rural Navarro properties use holding tanks; pump-outs are less frequent but essential.

    • What's included: pump out, tank integrity check, alarm verification, and a plan for wastewater disposal.
    • Typical cost in Navarro County: $400-$800 depending on tank size and access.
    • Navarro-specific notes: ensure local permits and disposal options are aligned with county regulations.

    Official guidance and resources

    • Texas Commission on Environmental Quality (OSSF program):
    • U.S. Environmental Protection Agency – Septic Systems: https://www.epa.gov/septic
    • For local context, consult Navarro County Environmental Health resources or the county website for any county-specific permit or inspection requirements.

    Cities & Communities in Navarro County With Septic Systems

    Corsicana & Surrounding Rural Areas

    • Corsicana city itself uses municipal sewer, but many homes on the outskirts and in nearby unincorporated neighborhoods rely on septic systems. If your property sits outside city limits, assume you may have a septic system unless you've confirmed otherwise.
    • Look for a septic tank and a buried drain field on the property map or through the county records.
    • Common maintenance needs: regular pumping every 3–5 years, careful disposal of oils and waste, and keeping the drain field free of heavy equipment or planting trees directly over it.

    Kerens & Surrounding Rural Areas

    • The Kerens area includes several rural pockets where septic systems are typical. Verify with the county or prior owners if you're unsure whether your home connects to a sewer line.
    • Typical signs of septic use: a buried tank, visible cleanout access, or a field with sparse, well-maintained vegetation.
    • Maintenance tips: avoid flushing non-biodegradable items, spread out water usage, and schedule inspections if you notice slow drains or wastewater odors.

    Frost & Surrounding Rural Areas

    • Many Frost-area properties on larger lots rely on septic systems. If you're renting or buying in these pockets, confirm your sewer situation with official records.
    • Key checks: locate the septic tank lid and drain field layout; review maintenance history and pumping records.
    • Best practices: conserve water, protect the drain field from traffic, and plant only shallow-rooted vegetation nearby.

    Mildred & Surrounding Rural Areas

    • Rural subdivisions around Mildred often rely on septic rather than municipal sewer. Property records or the Navarro County Health Department can confirm system type.
    • Common configurations: conventional gravity septic tanks or mound systems in high-water-table zones.
    • Care reminders: monitor for gurgling drains, back-ups, or damp spots—these may indicate a failing system needing professional service.

    Blooming Grove & Surrounding Rural Areas

    • In Blooming Grove's outlying areas, septic systems are a practical reality for many homes. Confirm with official records if your home is on private septic.
    • What to look for: a buried tank access port, a drain field, or maintenance paperwork from a licensed professional.
    • Maintenance focus: regular pumping, limit high-fat, oil, and grease inputs, and keep heavy equipment off the drain field.

    Purdon, Rice & Other Rural Pockets

    • Purdon and other small Navarro County communities with rural lots frequently rely on septic systems. If you live in an unincorporated part of the county, expect septic to be common unless you're connected to a sewer district.
    • Verification steps: check property deeds, recent permits, and any county health department notes about OSSFs (onsite sewage facilities).
    • Practical tips: install a tank riser if you don't have easy access to the septic, and keep a simple pumping schedule documented.

    Maintenance & Resources

    1. Get a current septic system assessment if you're buying, selling, or renovating. Request records from the Navarro County Health Department or a licensed septic contractor.
    2. Pump every 3–5 years, or as advised by a licensed inspector, to prevent solids buildup and scum accumulation.
    3. Practice water efficiency and protect the drain field from heavy loads, tree roots, and chemical exposure.
    4. Use official resources for guidance:
    5. Texas Commission on Environmental Quality (OSSF program): https://www.tceq.texas.gov/permitting/ossf
    6. Navarro County official site: https://www.co.navarro.tx.us/
    7. US EPA septic systems overview: https://www.epa.gov/septic

    Septic vs Sewer Across Navarro County

    How septic systems work vs sewer

    • Septic: a home-specific underground tank that holds wastewater, with a drain field where treated water percolates into the soil.
    • Sewer: wastewater is collected via local sewer lines and treated at a centralized facility.

    Key takeaway: septic is on-site, sewer is centralized. Your property's location and nearby infrastructure largely determine which option is practical.

    Where Navarro County homes typically connect

    • Rural areas tend to rely on private septic systems.
    • More urbanized pockets and towns with established municipal services are served by city or district sewer systems.
    • If you're outside a sewer service area, connecting to sewer may require significant infrastructure work or may not be an option.

    Pros and cons at a glance

    • Septic system
      • Pros:
        • Independence from monthly sewer bills.
        • Often lower ongoing costs in rural settings.
        • Flexibility in location on larger lots.
      • Cons:
        • Requires regular maintenance (pumping every 3–5 years, usage-dependent).
        • Risk of failure from improper care, heavy groundwater, or tree roots.
        • Local soil and groundwater conditions matter; not suitable for all sites.
    • Municipal sewer
      • Pros:
        • No septic tank pumping or field failures to manage.
        • Predictable monthly cost as part of a utility bill.
        • Typically better for homes with large wastewater loads (garbage disposal, baths, laundry).
      • Cons:
        • Ongoing monthly or quarterly charges, even if usage is low.
        • Connection and infrastructure costs if you're not yet connected.
        • Possible outages or maintenance disruptions in the network.

    What affects the choice in Navarro County

    • Proximity to an active sewer service area (costs and feasibility of connection).
    • Soil type, bedrock depth, and groundwater conditions (affect septic design and performance).
    • Lot size and slope (impact drain-field placement and feasibility).
    • Local permitting rules and timelines (OSSF considerations when septic; permitting for new sewer connections).
    • Long-term plans (property resale, development, or rural improvements).

    Steps to determine the best option for your property

    1. Identify your service status
      • Contact your city hall or county office to confirm whether your property is within a sewer service area.
      • Check any available service-area maps or contact the local utility.
    2. Compare costs and timelines
      • Get quotes for septic system replacement or upgrades.
      • Get quotes for connecting to municipal sewer (including any hookup fees and connection costs).
    3. Review maintenance and regulations
      • For septic: understand pumping schedules, inspections, and required setbacks from wells or structures.
      • For sewer: understand monthly rates and any backflow or outage policies.
      • Verify permits with the appropriate agency (see official resources below).
    4. Make an informed choice
      • Balance upfront costs, long-term expenses, maintenance requirements, and reliability.
      • Consider soil suitability, lot constraints, and future plans for the property.

    Maintenance and long-term considerations

    • Septic: pump every 3–5 years or as advised by a licensed professional; avoid flushing wipes, grease, solvents, or chemicals that damage bacteria.
    • Sewer: monitor for flood risk or sump pump backflow during heavy rains; report overflows promptly to the utility.
    • Regular inspections and professional servicing help prevent costly failures and protect shared water resources.

    Where to find official guidance

    • Texas Commission on Environmental Quality (TCEQ) – On-site Sewage Facilities (OSSF) program: