Wastewater treatment systems regulation – Environmental Health
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New OWTS regulation adopted April 13, 2026

septic leach field installation

Garfield County Public Health has updated its on-site wastewater treatment system (OWTS) regulation. This regulation is effective on May 28, 2026.
Request the Garfield County OWTS Regulation


Garfield County Public Health has included some administrative additions to the new Garfield County OWTS regulation to provide clarity on terms and processes.

Summary:

1. Definitions (OWTS Regulation Section 43.3)
Several definitions were added to provide clarity throughout the regulation and to define new terms specific to the Garfield County OWTS Regulation.

2. Inspections Required as Part of all Repair and Alteration Permits (OWTS Regulation Section 43.4.B)
These sections were added to codify an existing requirement that full system inspections are required as part of all repair and alteration permits. Inspections are necessary to determine if an existing system is functioning as intended per Section 43.4.B.7.a.

3. Denial of a Permit (OWTS Regulation Section 43.4.B.9).
This section was added to provide a process for applicants to appeal an application denial by Garfield County Public Health.

4. Demonstrations of Competencies for a Qualified OWTS Professional (OWTS Regulation Section 43.4.K)
This is a new definition specific to Garfield County that specifies competencies that demonstrate an individual is qualified to provide OWTS services. Certification and licensing with Garfield County is not a requirement to be a “Qualified OWTS Professional”.

5. OWTS Inspection Requirements (OWTS Regulation Section 43.4.L)
This section specifies what items shall be included in OWTS inspection reports as part of all repair and alteration permits.

6. Variance Procedure Guidance (OWTS Regulation Section 43.4.N)

These sections were added to provide clarity to all variance procedure applicants on what is required and expected from them in the variance procedure process.

View a detailed review of the changes to the Garfield County OWTS Regulation.

Garfield County Public Health has provided a summary of the state-mandated changes to the Garfield County OWTS Regulation. This is an educational tool and not an exhaustive list.

Summary:

  1. New definitions

Several new definitions have been added to clarify technical understandings of man made and natural structures and assist with accurate enforcement and interpretation of the OWTS Regulation.

  1. Additional new septic tank and pipe requirements

Safety devices and pipe strength requirements have been added for tanks, seepage pits, and vaults.

  1. Clean outs must be located within 50 feet of the outside wall

The previous requirement of 5 feet outside the building has been increased.

  1. New serial distribution systems are prohibited
  1. New soil classifications and soil treatment area design requirements

Minor changes and additions have taken place to the adjustment factor and long-term acceptance rate tables. Requirements for soil evaluation, profile pits, and sand have been added or changed. Significant edits have been made to the design criteria table for rock-type soils.

  1. New treatment Level TL3ND has been added

 A new treatment level requiring disinfection has been added in addition to requirements for the disinfection systems required to reach this level and provisions for reduced vertical separation requirements.

  1. New Final Document(s) requirements

 Sand gradation and squirt height documentation requirements have changed.

  1. Accessory Dwelling Units (ADUs) and Vacation Rental requirements have been clarified and added
  2. Pressurized distribution requirements have seen minor updates
  3. Sand filter allowable parameters and requirements have been updated
  4. Mound system requirements have seen major updates and clarifications

View a detailed review of the Colorado-required updates for Garfield County OWTS Regulation

 

  • August 5, 2025, Board of County Commissioners Work Session. Presented a summary of CDPHE changes to the Colorado OWTS Regulation 43.
  • February 3, 2026, Board of County Commissioners Work Session. Present the proposed Garfield County OWTS Regulation to the Board of Health.
  • February 4 through April 3, 2026: Solicit Stakeholder comments and feedback on proposed Regulation
  • April 13, 2026, Board of Health Public Hearing to adopt proposed Garfield County OWTS Regulation.
  • May 28, 2026, Adopted Garfield County OWTS Regulation becomes effective.
  • Per state law, Garfield County updated OWTS Regulation must be effective no later than June 15, 2026.

To view the adopted Colorado OWTS Regulation 43, please visit:

Colorado On-site Wastewater Treatment System Regulation 43

Colorado OWTS ACT