Septic and Well Information

Onsite Wastewater Treatment Systems (Septic Systems)

The Department of Public Health is responsible for the regulation of Onsite Wastewater Treatment Systems (OWTS) in Gilpin County. 

2026 Updates to Regulation 43

On-site wastewater treatment systems (OWTS), also known as septic systems, are governed in Colorado by Regulation 43.  The Colorado Department of Public Health and the Environment (CDPHE) adopted a new version of Regulation 43 on March 10, 2025 and requires all Colorado counties adopt a version that is as strict or stricter.  There will be a public hearing regarding Gilpin County’s new regulations on January 27th   at 9:30 am at the Gilpin County Board of Commissioners meeting held at the Gilpin County Old Courthouse, 203 Eureka St, Central City. The draft version of Gilpin County’s new version of Regulation 43 is posted below for comments and feedback. Written comments may be submitted via email to awitt@gilpincounty.org, or mailed to Gilpin County Public Health 15193 CO-119, Black Hawk, CO 80422. Comments must be received by January 19, 2026 to be considered.  If these regulations are adopted on January 27th, they will go into effect in Gilpin County on March 13th, 2026.

Gilpin County Draft Updated Regulation 43

*Please note that the Draft Regulation 43 document has not been remediated to meet full accessibility standards. Under the Gilpin County Accessibility Plan (See 8 CCR 1501-11:11.5.D), and pursuant to 8 CCR 1501-11:11.5.C., Gilpin County will provide reasonable modifications or accommodations, when requested, to remove accessibility barriers (unless exempt under 8 CCR 1501-11:11.10) at no cost to the requestor.

If you require a print copy of the draft regulations for accessibility purposes, please email mlarson@gilpincounty.org.*

Onsite Wastewater Treatment System Construction Permits and Major and Minor Repair Permits

Inspections are done on Tuesdays and Thursdays. You can request an inspection online through the permit portal. If you need assistance scheduling an inspection, please contact Environmental Health Specialist Mack Yaun at (720)-617-7779.

Apply to Construct/Repair/Modify an OWTS

A construction permit will be required for the following: 

• new system installations
• existing system upgrades and expansions
• existing system replacements

Major system repairs are defined as the repair/replacement of system components not matching the recommended components from the original engineered design plans. New engineered design plans will be required. Any work performed on system components for a system older than 30 years or systems without an engineered design plan will be considered a major system repair and engineered plans will also be required.

Minor system repairs are defined as the repair/replacement of system components matching the recommended components from the original engineered design plans. New engineered design plans will not be required.

Permits will not be required for replacing sewer line not entering a system component and routine O&M work such as replacing effluent filters.

Use Permits for Title Transfer/Selling a Property

If you are selling a property with a home in unincorporated Gilpin County, you must have the property's septic system inspected and obtain a Use Permit prior to going under contract. Failure to obtain a Use Permit prior to the date of a covered transaction can subject you to daily accruing penalties under Colorado law. 

Do you need to obtain a use permit when:

1. You are selling a home in unincorporated Gilpin County? Yes.
2. You are selling a home in unincorporated Gilpin County with an OWTS (septic system) that was permitted and installed 5 years or less from the date of sale? No.
3. You are selling vacant land? No.
4. You are selling vacant land with an installed OWTS but it is not connected to a permitted home or commercial structure and not operational? No.
5. You are selling vacant land with a permitted but unfinished/unconnected/non-operational OWTS? No.
6. You are selling a property with a permitted but unfinished home or commercial structure that is connected to a permitted but non-operational OWTS? No.
7. You are selling a home or property with limited use structures such as seasonal cabin or home that is not connected to a permitted OWTS? Yes.
8. You are selling a home that is connected to a sealed vault type OWTS? Yes. 

There are two separate use permit applications. One for conventional treatment level systems (TL1) and one for higher level treatment systems (TL2+) that require the property buyer or title grantee to obtain a maintenance contract and Operating Permit. It is your responsibility as the seller/title grantor to inform the buyer of these requirements. Failure to do so can result in enforcement action against you. Use permits are valid for 6 months and must be obtained prior to the transaction date of the transfer of property subject to the use permit requirement. Active and unexpired use permits can be easily extended as long as you request the extension prior to expiration of the permit. 

Apply for Use Permit TL1 Conventional System

Apply for a Use Permit & Operating Permit TL2+ Higher Level System

Operating Use Permits and Maintenance Contracts without Title Transfer/Selling a Property

All high level treatment systems (TL2+) are required to have an operating use permit. A maintenance contract from a licensed septic contractor must first be obtained. Then apply for the operating use permit TL2+ higher level system. On step 3, select “Operating Permit Only (I’m the property owner and I am not currently selling or transferring the property)”. Upload the current signed maintenance contract in the attachments step. There is no fee for this permit.

OWTS Property Records

Homeowners may request copies of their OWTS records by emailing mlarson@gilpincounty.org. 

If you are not the property owner, copies of a property's OWTS records can be obtained by filling out a Colorado Open Records Act Requests form on the Clerk and Recorder’s webpage. CORA requests may take up to three business days. 

Onsite Wastewater Regulations and Fees

Comprehensive Fee Schedule 2025

Gilpin County OWTS Regulations 2018

Colorado Regulation 43

Wells

View the recorded webinar from February 11th, 2025 on Radon, Well, and Septic information presented by Gilpin Public Health and the Gilpin CSU Extension Office

The use and construction of private wells is regulated by the State of Colorado Division of Water Resources. To apply for construction of a well, locate permitted well records, and to view the state's well permit map click below: 

DNR Well Permitting

Well Water Testing Services 

Resources

CSU Private Well Fact Sheet

EPA Site for Septic Information