Sarah Eisenstat, Peter Dyke
Papers # 2018 Las-Vegas
Many cities in the US are operating their water utility on a “manage to fail” basis, meaning they are replacing >100-year-old pipes at a cycle time of over 150 years. At this rate, most of the pipes will have failed before they can be replaced. Ft. Wayne, IN made the realization that PE pipe is the solution due to its durability and longevity. There has been extensive testing on why HDPE pipe is durable and there are standards and tests to ensure that it can last over 100 years in the ground.
Many municipalities treat their systems on a manage-to-fail basis. Replacement schedules are drawn out to where failures and leaks steadily increase over time placing a burden on water operations. Maintenance dollars and repair dollars could be used for capital improvement, but they are not because the needs for repair grow over time. Water system operations in Fraser, MI, the Oroville Dam, Los Angeles, San Antonio Water System, Louisville, KY, and the City of Philadelphia are used as examples to describe this “manage to fail” practice.
The Oroville Dam failure resulted in the evacuation of 188,000 people and an $850 million fix. The state was warned to go beyond a visual inspection as cracks were visible on the dam given the cracks had been found repeatedly since 2009. This dam was managed to the point of failure.
Fraser, MI bought a wastewater interceptor line from another utility with a known history of costly failures. In 2016, a sinkhole formed as a result of the failed large diameter sewage line. This failure affected sewage operations for 500,000 residents in 11 communities. The cost of rehab would have been $6 - $8 million had it been dealt with properly, but it turned out to be a $150 million repair bill.
Ft. Wayne, IN made the decision to rehab with HDPE due to the drastically increasing amount of water main breaks in their system. Since then, they’ve seen a steady decrease in main breaks. Utilities should consider the Ft. Wayne best practice model.
It is important to note that HDPE use has a positive effect on water treatment capacity, lowers electricity cost, and positively affects the social costs of roads that are undermined by water leaks. Water loss has been proven to be significantly reduced and water quality is preserved.