​Holiday Closing: all county offices are closed Monday, May 30, for the Memorial Day holiday, and will re-open Tuesday, May 31. This includes parks offices, public works, courts and all other administrative offices.

OSSF Permits and OSSF Related Information

On Site Sewage Facility (OSSF) Permits

OSSF Information Sheet

Permit Application

ETJ Platting Verification Form

Aerobic Wastewater Treatment Systems Information

911 Rural Addressing Application

Culvert Permit Application

Affidavit of OSSF Requiring Maintenance

Inspection Handout

Site Evaluator Information Sheet

TxDOT Driveway Permit Information Sheet

The Dirty Dozen: 12 Tips to Prevent Storm Water Pollution Brochure

Preventing Stormwater Pollution at Construction Sites Brochure

TCEQ Construction General Permit Requirements Brochure

Maintain your septic system to protect well water

To save the form to your computer, right click on the link and select "Save As". To view form in your browser, simply click the link.

OSSF Information

To determine if the on-site sewage facility on your property is due for an inspection, view the report below:

Aerobic System Maintenance Due Report (Sorted by Installer/Maintenance Company)

For the rules and regulations pertaining to on-site sewage facilities, please review the court order provided below:

On-Site Sewage Facilities Rules and Regulations (CO# 2008-187-03-11)

Subdivision Plat OSSF Review Application


On Site Sewage Facilities (AKA "Septic")

Do I need to apply for OSSF (On-Site Sewage Facility) through Collin County?

  • If your property is located OUTSIDE of city limits – you are required to apply for an OSSF permit through Collin County Development Services.  You can find the permit application, as well as other helpful information, Here.
  • If your property is located INSIDE of city limits – you MAY BE required to apply for an OSSF permit through Collin County Development Services.  The Texas Commission on Environmental Quality (TCEQ) maintains a List of the permitting agency (Authorized Agent) for each city.  If your city is not listed, Collin County is your Authorized Agent.

Where do I find a Registered Sanitarian or Professional Engineer to design a new OSSF or design a repair to an existing OSSF?

Collin County maintains a courtesy List of local individuals that have the approved, required credentials to perform OSSF design work in Collin County.  The list is provided solely for your convenience.  Collin County in no way recommends or guarantees the work of any of the individuals on the list.  You may choose any currently licensed Registered Sanitarian or Professional Engineer to perform your work.

Where do I find an Installer or Maintenance Provider for my OSSF?

The Texas Commission on Environmental Quality (TCEQ) maintains a List of certified/licensed providers.

What rules do I have to follow for OSSF?

In addition to the State Rules (scroll down and choose Chapter 285) for OSSFs, Collin County has a Court Order that details additional, more stringent rules that must be followed.

Where do I file the OSSF Affidavit?

The Affidavit must be filed with the County Clerk's Office located at 2300 Bloomdale Rd., Suite 2104, McKinney, TX.

Does my OSSF permit have an expiration date?

OSSF permits expire after 365 days of no activity (from date of issuance)

I have purchased a property that has an aerobic OSSF system.  How do I register the OSSF in my name?

Collin County requires three (3) forms when property is sold that has aerobic system:  (1) Change of Ownership (2) Aerobic Wastewater Homeowner's Information sheet (3) Maintenance contract in new owner's name (must be obtained from your licensed maintenance provider). 

Where do I send OSSF Contracts, Maintenance Reports or Change of Ownership Forms?

You can either mail them to:  4690 Community Ave., Suite 200 McKinney, TX 75071, fax to 972/548-5555

or by email.