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On-Site Sewage Facility (OSSF) Regulation & Inspection
OSSF Fee Increase - effective February 1, 2016, a $200 increase per permit, a $20 increase for extra inspections and a $25 increase for a new design review went into effect. Read more...
OSSF Fee Schedule
On-Site Sewage Facility Rules
Williamson County and Cities Health District (WCCHD) adopted a new Order to update the On-Site Sewage Facility Rules. The Order became effective on April 28, 2015. WCCHD has regulatory jurisdiction in all areas of Williamson County, with the exception of those areas that are located within the City of Austin. Below are links to the new OSSF Order, a Summary of Changes from the 2008 WCCHD OSSF Order and a document containing Frequently Asked Questions regarding the new Order.
WCCHD Environmental Health Services is the authorized agent of the Texas Commission on Environmental Quality (TCEQ) for Williamson County.
The following property types must be connected to an approved On-Site Sewage Facility (OSSF), or be connected to an authorized wastewater disposal system:
- New or altered single family dwelling
- Multi-family dwelling
- Business, commercial, or industrial structure
Review the OSSF Guide for Williamson County for complete regulations and application process.
How to Apply for a Permit
If you are installing a new OSSF, or modifying (i.e. repair or enlargement) an existing OSSF on your property, an application is required. In addition to the application, please complete and submit the permitting requirements checklist. A complete submittal of Part I of the checklist is required before WCCHD can begin the application process. Please review the Instructions/FAQs document before completing the forms.
- Instructions/FAQs for Submitting an OSSF Application
- OSSF Permitting Requirements Checklist
- Application for Williamson County OSSF [ .pdf ] [ .doc ]
- Flood Plain Management
- Proposed Subdivision Regulation
In addition to the above residential requirements, a completed Commercial Use Questionnaire must be submitted with the design packet for a commercial building. [ .pdf ] [ .doc ]
Re-Inspection of an Existing Residential OSSF:
Most mortgage lenders require a re-inspection of an OSSF whenever a property is sold. Environmental Health Services staff perform a surface inspection for this purpose. The Application for Evaluation of an Existing On-Site Sewage Facility form describes the scope and limitations of this inspection.
More information: For more about the Residential OSSF permit process, contact Paul Walter at 512-943-3620, for Commercial OSSF information, contact Steve Gilmer at 512-943-3620.
- Application for Evaluation of an Existing On-Site Sewage Facility
- Chapter 285 Changes 9-1-12, Prevention of Unauthorized Access
- WCCHD Approved Aerobic Control Panels Prior to 2015
- WCCHD Approved Aerobic Control Panels Effective 4-28-2015
- OSSF ATU Transfer of License/OSSF Renewal Application
- WCCHD Aerobic On-Site Sewage Facility Affidavit
- Your Proline Aerobic Treatment Unit (ATU)
- NSF Update for Proline (ATU)