Publications & Research

Soil Resources

Soil Observation Log

Soil Texture Chart

Profile Hole Criteria

Design Guidance

The Colorado Department of Public Health and Environment (CDPHE) Clean Water: On-site Wastewater Treatment System Website has many resources including approved septic tanks and technology as well as clarification documents and design aids.

 

CDPHE OWTS Website

https://cdphe.colorado.gov/OWTS

Regulation 43 – effective 6/15/2025

CPOW Guidance Document for NDDS October, 2024

 

Training Videos

Soil Hand Texturing

Colorado Soil Texturing

Colorado Test Pit Demonstration

NDDS Installation Video

OWTS Pressure Distribution

CPOW Logo

CPOW Logo for Member Use

Research

There are many institutions and organizations that are researching various areas of onsite wastewater treatment systems. Here are just a few:

• Colorado School of Mines
• Decentralized Water Resources Collaborative
• University of Tennessee
• University of Minnesota
• Water Environment Research Foundation
• Water Environment Federation

Related OWTS links

• EPA, Septic System Frequently Asked Questions(opens in new window).
• EPA Onsite/decentralized systems(opens in new window).
• USDA Natural Resources Conservation Services (NRCS) Soils(opens in new window).
• National Association of Wastewater Technicians (NAWT)(opens in new window).
• National On-site Wastewater Recycling Association (NOWRA)(opens in new window).
• Colorado Professionals in On-site Wastewater (CPOW)(opens in new window).