Cheyenne Water Distribution System
The water distribution system in Cheyenne includes four prestressed concrete cylinder pipelines (PCCP), approximately 13.5 mi long. The 16 to 30 in. dia., lined-cylinder pipes (LCP) were installed between 1950 and 1962. Three of the PCCP carry raw and treated water, and the fourth is a part of the distribution system. SGH assessed the condition of all four lines while they remained in service.
Highlights of SGH’s work include the following:
- Data collection and review of historical records
- Corrosion survey including electromagnetic conductivity testing
- Geotechnical and groundwater investigations
- External test-pit inspection of pipe
- Testing of mortar coating and prestressing wire samples
- Hydraulic transient analysis
- Structural evaluation of LCP
- Failure risk analysis of pipe assuming broken prestressing wires and corroded steel cylinder
We found that the lines had performed well, and there were no systematic factors that presented a significant risk of future failure.