Septic rules and requirements in Collin County, Texas
Septic permits in Collin County are issued by the Collin County Development Services. A new system permit costs $310. USDA rates most of the soil in the county Very limited for septic absorption fields — 98.9% of the rated acres. Collin County Development Services -- OSSF Aerobic Systems Information Sheet · checked 2026-09-23
Collin County Development Services
Issues the permit
checked 2026-09-23
$310
Septic system permit
checked 2026-09-23
Very limited
USDA rating, 98.9% of rated acres
checked 2026-09-23
Who issues septic permits in Collin County?
Collin County Development Services, at 4690 Community Ave., McKinney, TX 75071, (972) 548-5585. It is part of county government. The state writes the rules it applies.
Collin County Development Services -- OSSF Aerobic Systems Information Sheet · checked 2026-09-23
What does a septic permit cost in Collin County?
$310 for a septic system permit, on the county's own schedule.
Applies to a new gravity system for a home with no maintenance contract.
| On-Site Sewage Facility Re-Review | $50 | any system |
|---|---|---|
| Repair Existing Septic System | $100 | a system the source lists as less than 100' of line, with no exchange of tanks |
| Repair Existing Septic System | $150 | a system the source lists as over 100' of line, or with an exchange of tanks |
| Subdivision/Plat Review of Private Sewage Facilities | $100 | a system, per 15 per lot the source lists as $15 per lot, plus $100 |
| Wastewater Inspection - New Commercial Construction (no Maintenance) | $450 | a business with a conventional, no maintenance system |
| Wastewater Inspection - New Commercial Construction (w/Maintenance) | $475 | a business with a aerobic, with maintenance system |
| Wastewater Inspections - New Residential Construction (no Maintenance) | $310 | a home with a conventional, no maintenance system |
| Wastewater Inspections - New Residential Construction (w/Maintenance) | $335 | a home with a aerobic, with maintenance system |
| Wastewater Inspections - Re-Inspection | $75 | a system the source lists as after failure of the first inspection |
| Wastewater Review for Existing Septic | $50 | a system the source lists as if 50% of the system will be repaired or upgraded, the county requires a new-OSSF permit |
| Development Permit - New Construction | $75 | a system the source lists as total fee made up of a $20 Flood Plain Development Review fee, a $15 Lot Subdivision Check fee, and a $15 On-Site Sewage Facility Compliance Review fee |
Part of this fee goes to the state.
Collin County Adopted Fee Schedule FY 2026 -- Development Services · checked 2026-09-23
Is the soil in Collin County suitable for a septic system?
USDA rates most of the county Very limited for septic absorption fields — 98.9% of the rated acres. A rating describes the ground, not a parcel. The county's site evaluation decides each lot.
USDA NRCS Soil Data Access (SSURGO) · checked 2026-09-23
What Collin County inspects, and how often
Every 4 months for an aerobic system under a maintenance contract. The county checks it three times a year.
The county gets a copy of each report.
A licensed maintenance company checks it. The county also checks for spot visits and complaints.
Collin County Development Services -- OSSF Aerobic Systems Information Sheet · checked 2026-09-23
What Collin County sets itself
The state writes the code. Collin County adds the rules below. They are what makes this page differ from the Texas requirements.
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A lot must have at least one usable acre. A lot with a water well needs one and a half acres, with one acre usable.
Applies to a lot used for an on-site sewage facility.
The date the county platted the lot decides the exact rule. Development Services can confirm it for a lot.
Collin County Development Services -- On-Site Sewage Facilities · checked 2026-09-23
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Every septic system in the county needs a permit. The lot's size does not change this.
The county's order lists this as stricter than the state's rule.
Collin County Commissioners Court Order No. 2008-187-03-11 -- On-Site Sewage Facilities Rules and Regulations · checked 2026-09-23
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4 months
Applies to an aerobic system under a maintenance contract. The county checks it three times a year.
The county gets a copy of each report.
Collin County Development Services -- OSSF Aerobic Systems Information Sheet · checked 2026-09-23
Sources
Each figure above has a government source and a checked-on date. USDA's Soil Data Access service supplies the soil records. A script writes them, and nobody types them.
- Collin County Development Services -- OSSF Aerobic Systems Information Sheet
- Collin County Development Services -- On-Site Sewage Facilities
- Collin County Commissioners Court Order No. 2008-187-03-11 -- On-Site Sewage Facilities Rules and Regulations
- Collin County Adopted Fee Schedule FY 2026 -- Development Services
- Texas Administrative Code, Title 30, Chapter 285, Section 285.30, Site Evaluation
- Collin County Development Services -- How to Apply for a Permit (CSS Portal)
- USDA NRCS Soil Data Access (SSURGO)
Verify before you act. Septic rules are set locally and they change. Check anything here before you spend money on it. Call the Collin County Development Services, on (972) 548-5585.