Revised OWTS Manual – May 21, 2019

The Onsite Waste Treatment Systems (OWTS) Manual provides the regulations, procedural and technical details governing individual onsite wastewater treatment systems (also referred to as septic systems). State law mandates the State Water Resources Control Board (State Water Board) adopt standards for regulation of onsite waste treatment systems ( State Water Board OWTS Policy). The OWTS Manual complies with the State Water Resources Control Board OWTS Policy Tier 2 Local Area Management Program (LAMP) requirements.

Below is the proposed OWTS Manual that was considered by the Board of Supervisors on May 21, 2019. It incorporates feedback from the public.

Go Back to main OWTS Manual Revision page

May 21, 2019 Version

Full Portfolio Version (PDF Portfolio: 9.02 MB)

The individual PDFs that are listed below, combined into a single Adobe Portfolio file. (Requires Adobe Flash installation to view.)

Revised Sections (Accessible)

Alternate version divided into separate sections in separate PDF files. All documents are in PDF format and fewer than 200 kB in size unless otherwise noted.

• OWTS Cover and Table of Contents
• Section 1 – General
• Section 2 – Sewer Connection Required
• Section 3 – Acronyms and Definitions
• Section 4 – Criteria for All OWTS
• Section 5 – Abatements, Abandonments and Repairs of Failing Systems
• Section 6 – Requirements for Approval of Building Permits
• Section 7 – Site Evaluation Methods and Investigation Requirements (Size: 393 kB)
• Section 8 – Criteria for OWTS Components (Size: 558 kB)
• Section 9 – Criteria for Standard OWTS
• Section 10 – Criteria for Water Reuse
• Section 11 – Criteria for Commercial, Industrial, and Institutional OWTS
• Section 12 – Non-Standard Experimental and Alternative OWTS Approval Process
• Section 13 – Non-Standard Experimental and Alternative OWTS Standards (Size: 2.57 MB)
• Section 14 – Non-Standard and/or Commercial OWTS Operational Permit and Monitoring
• Section 15 – Vesting Certificates
• Section 16 – Subdivisions and Lot Line Adjustment Requirements
• Section 17 – Variance Requirements
• Section 18 – Variance Prohibition and Special Standards Areas (Size: 3.35 MB)
• Section 19 – Dispute Resolution
• Section 20 – Tier 3 Treatment, Monitoring, Inspection and Sampling for Supplement Treatment Units
• Section 21 – Waterless Toilets
• Appendix A