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On-Site Wastewater Treatment Systems (OWTS)

On-site Wastewater Treatment Systems (OWTS), more commonly known as septic systems, have traditionally been called Individual Sewage Disposal Systems (ISDS) in Colorado.  Regulation 43: On-site Wastewater Treatment System Regulation (Regulation 43) was adopted May 13, 2013 and became effective June 30, 2013.  The On-site Wastewater Treatment System Act can be found on the Water Quality Control Commission website.
The implementation of Regualtion 43 will be phased in.  The schedule is dependent on the design capacity of the system.
For OWTS with design capacities less than 2,000 gpd:
  • Permitting of individual OWTS is conducted at the local level, although an initial State acceptance of equipment and technology is required.
  • The exisiting local OWTS/ISDS/septic system regulations will remain in place until the local Board of Health has adopted new OWTS regulations.  The local Boards of Health have one year from the effective date or June 30, 2014, to adopt new local regualtions.
  • For Local Public Health Agencies submitting draft regualtions for review, we can more efficiently track and review your regulation if you would please use the:
  • Implementation of the soil test pit excavation procedure can occur over three years.
  • State acceptance of equipment and technology is required under Regulation 43.  To submit a distribution product, tank, treatment or other equipment/technology for acceptance, please use the appropriate Review Submittal Form below so we can more efficiently track and review your informaiton.
For questions related to OWTS with design capacity less than 2,000 gpd, please contact Chuck Cousino, On-site Wastewater Treatment System Coordinator, at chuck.cousino@state.co.us.
For OWTS with design capacities equal to or greater than 2,000 gpd, the following policy will be followed:
  • For projects with site location applications submitted on or after July 1, 12013, the design engineer must use Regulation 43 as the design criteria.
  • The individual system approval process follows the Domestic Wastewater Facility Approval process.  To access the DWFA page, please click here.
For questions related to OWTS with a design capacity of 2,000 gpd or larger, please contact David Kurz, Lead Wastewater Engineer, at david.kurz@state.co.us.