In 2009, UAF recognized their 60-year old sewer system was failing. Wood stave pipes had deteriorated, techite pipe was cracked, cast iron was severely corroded and emergency repairs were needed on a regular basis. PDC prepared a Campus-wide Sewer Assessment to analyze the condition and prioritize needed improvements. These improvements have included relining, replacement, and even complete rerouting in some cases. UAF has made a commitment to stick to the plan and as a result, about 85% of the entire campus sewer system is stable and mission-ready for the next 50 years.
The sewer assessment included video inspection of 27,000 feet of pipe, inspection of 140 manholes, and 15 lift stations. More specific tasks included:
- Surveying of all manholes
- Video inspection of pipes
- Visually inspecting all manholes
- Measuring flows at five locations using Flo-Dar flow meters
- Estimating future demands
- Assessing I&I
- Performing a hydraulic assessment using a SewerCAD system model
- Assessing facilities’ condition based on review of video inspections
- Developing a GIS system of the system evaluation and associated data
Based on the assessment, PDC developed system alternatives to prevent overloading of pipes and eliminate the need for 4 existing lift stations. Other alternatives we considered included comparisons of rehabilitation with cured-in-place pipe lining to complete replacement for selected segments of pipe. The preferred alternatives were prioritized and presented in the master plan.
The recommendations in the report were used to pursue funding from the state legislature. Since completion of the assessment PDC has assisted UAF in reviewing priorities on an annual basis.