Tri-County Health Department regulates all individual sewage disposal systems (ISDS) in Adams, Arapahoe and Douglas Counties. Proper site evaluation, system selection and layout, installation, inspections and maintenance are essential in the onsite treatment of sewage on properties that cannot be served by publicly-owned collection and treatment systems. (Publicly-owned systems collect and move sewage from many properties to a single sewage treatment plant, located away from the properties it serves.)

The scope of the ISDS program includes:
1) Issuance of permits (after plan review and site evaluation)
2) Final installation, inspections and certification before the system is put into use
3) Investigation of malfunctions of established systems
4) Enforcement (issuing orders to correct problems and actions against system installers and cleaners)
5) Activities to assure that ISDS are inspected and maintained by responsible management entities

Rules and Regulations
Regulation No. I-11, Individual Sewage Disposal Systems (adopted by the TCHD Board of Health April 5, 2011, effective July 1, 2011). (3MB - 105 pages)

For more information, contact one of our field offices:
Administration: 720-200-1670
Commerce City: 303-288-6816
Aurora: 303-363-3055
Castle Rock: 303-663-7650

Downloadable Forms and Referrals:

New/Expand/Repair Permits:
• Application to install, expand or repair
• Requirements for submitting application
• Policy on submittal of documents
• Sample plot plan

Use Permits:
• Application
• Agreement to repair
• Use permit inspection form
• Guide to use permit inspection form
• Repair verification form
• Use permit questions and answers Q&A
• List of certified use permit inspectors

Guidelines/Regulations:
• How to select an ISDS Professional
• Septic care and maintenance guidelines
• Regulation No. I-11 (3MB - 105 pages)
• Standing water in monitoring pipes
• Vegetation over absorption areas

Engineers:
• Percolation test result form
• Percolation test and soils data form
• List of licensed engineers

Installers/Contractors:
• Onsite systems as-built drawing form
• Application to install a lift station
• List of licensed installers
• Affidavit of Citizenship

Cleaners:
• Septic cleaners log
• List of licensed cleaners
• Affidavit of Citizenship

Related Tri-County Pages:
• Environmental Health Homepage
• A–Z Index of Topics and Services
• Animal-Borne Diseases
• Body Art Establishment Inspections
• Child Care Center Inspections
• Disease Prevention
• Emergency Preparedness
• En Español / In Spanish
• Going "Green"
• Health Inspections
• Household Hazardous Waste Roundups
• Indoor Air Quality / Mold
• Industrial Hygiene / Occupational Health
• Land Use and Planning Services
• Meth Lab Cleanup
• Restaurant Inspections
• Rocky Mountain Arsenal
• Swimming Pools and Spas
• Water Quality
• West Nile Virus

Related Links and Fact Sheets:
• Drinking Water from Wells - EPA (Website)
• Drinking Water from Wells - EPA - (Brochure)
• Medication Disposal Sites
• Septage Brochure
• State Regulations
• Waterborne Diseases

Kids Pages:
• Chemicals Around the House
• Drinking Water and Groundwater (EPA)
• Environmental Explorers (EPA)
• EPA Student Center
• Water Treatment Cycle (EPA)

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