An On-Site Wastewater Treatment System (OWTS), commonly known as a septic system, treats sewage on an individual’s property in the ground. Septic systems are installed on properties that cannot be served by publicly-owned wastewater collection and treatment systems which move sewage away from properties. Proper site evaluation, system selection and layout, installation, inspections and maintenance are essential in the onsite treatment of sewage.
Tri-County Health Department regulates all OWTS in Adams, Arapahoe, and Douglas counties and the program includes:
- Issuance of permits to install, repair, expand, use, or operate a system
- Plan review, site evaluation(s) before installation, final inspection(s) after installation, and certification before the system is put into use
- Investigation of malfunctions of systems
- Septic Care & Maintenance Guidelines
- Recommendations for Selecting a Septic Professional
- Standing Water in Monitoring Pipes
- Vegetation Over Absorption Areas
- EPA SepticSmart
- Field Book For Sampling and Describing Soils - Natural Resources Conservation Service
- Mound Systems
- Distribution Networks
- Natural Resources Conservation Service Web Soil Survey
- Clarification Regarding the term “Infiltrative Surface” - Colorado Department of Public Health and Environment
- Clarification Regarding Soil Replacement - Colorado Department of Public Health and Environment
- EPA Onsite Wastewater Treatment Systems Manual - Environmental Protection Agency
- Clarification for Determining the Number of Chamber Units in OWTS Design Under Regulation 43 - Colorado Department of Public Health and Environment
Regulation, Applications, and Forms
- Regulation No. O-14, On-Site Wastewater Treatment Systems (revised effective February 23, 2015)
- Shallow Waste Disposal System/Well Inventory Request Form - Environmental Protection Agency (EPA). Required for commercial systems.
A septic permit is required for new installations, expansions, and repairs (with some exceptions). To obtain a permit, the following will be required: completed permit application, payment of permit fee, soil investigation and design document. Under certain conditions, the OWTS must be designed by a Colorado Licensed Professional Engineer. Tri-County can accept the applications at our Environmental Health Offices, or via email at: firstname.lastname@example.org. Tri-County staff will then review the information and make a site visit. If the application, engineer design (if applicable), design document and site meet our requirements, Tri-County will issue a permit to construct or repair an OWTS. Tri-County may require additional information depending on the conditions at the site. After the system is constructed (but before it's covered with soil) or is repaired, Tri-County staff will make a final site visit to ensure the work was completed per the OWTS Regulations. A green tag will be issued when the system is approved as well as a Use Permit.
A “Use Permit” expressly authorizes the use of a septic system. The most common circumstances that require obtaining or renewing a “Use Permit” include the sale or change of ownership of a property, change in use of the property (i.e., a residence is changed to a business), additional bedrooms added, or a separate “modular” home added. For more information review the Use Permit Questions and Answers document below.
Finding Septic Professionals
- How to Select a Septic Professional
- List of Septic Engineers
- List of Licensed Installers
- List of Licensed Cleaners / Pumpers
- Certified Use Permit Inspectors (Search)
Septic System Installers / Contractors
A person or company installing or repairing an On-Site Wastewater Treatment System in Adams, Arapahoe, or Douglas County must be licensed with Tri-County Health Department. To obtain a license, Tri-County must receive a completed application, affidavit of citizenship, and license fee. In addition, the applicant must take and pass the system’s contractor exam. The exam covers various sections of the Onsite Wastewater Treatment System Regulation and you can take an exam at one of our four Environmental Health offices during business hours. The license is valid from January 1 to December 31 and must be renewed every year. If your license is not renewed by January 31, then you will be required to retake and pass the exam.
Septic Tank Cleaners / Pumpers
A septic system cleaner / pumper must be licensed with Tri-County Health Department. To obtain a license, Tri-County must receive a completed application, affidavit of citizenship, and a license fee. The license is valid from January 1 to December 31 and must be renewed every year. Cleaners / Pumpers must also maintain a Septic Cleaners Log.
- How do I get a permit to build a new, or repair an on-site wastewater treatment system (OWTS)?
- Under what conditions must an on-site wastewater treatment system (OWTS) be designed by a Colorado Licensed Professional Engineer?
- How do I get a Use Permit?
- Who can do Use Permit inspections?
- I am moving and need to get my septic system certified. What do I do?
- What is the minimum lot size for an on-site wastewater treatment system (OWTS)?
- How often do I need to pump my septic tank?
- Will I be able to irrigate or have horses where my absorption field is located?
- Can I install a bathroom in a garage, barn, etc., and connect it to my existing on-site wastewater treatment system (OWTS)?
- I am unsure where my septic system is located. Do you have records of my system?
- I accidentally damaged some components of my septic system. Who should I call to inspect and repair the damage? Do I need a permit?
- Do I need a license to install and repair septic systems?
- How do I become a licensed septic system pumper/cleaner?
- How do I become a Certified Use Permit Inspector?
- Can Tri-County recommend an Septic System Professional such as an installer or pumper?