The Crisis: Cloudy water, and sometimes, very little water at all.
The City of McKinney had received occasional complaints regarding potable water clarity and low-pressure concerns for 9 years. The city has miles of unlined cast iron water mains, which are more than 65 years old. The lines were starting to experience internal corrosion. Temporary solutions had been employed including maintenance flushing of mains and installation of water filters at meter boxes. However, complaints continued to increase with as many as 140 discolored water claims in a four-month period.
The Solution: CuraFlo Spincast.
In January 2007, the City Council approved additional funding through its Capital Improvements Projects budget to initiate a multi-phase replacement of the deteriorating water mains. Harlyn Farrell, Water Superintendent for the City of McKinney, evaluated various methods of replacement and renewal and in July 2007, an additional contract was entered with CuraFlo Spincast Services to rehabilitate an additional 14,000 feet with an epoxy lining.
The majority of pipes were located along the roadway under asphalt and concrete. The mains also ran along the front of properties and in some cases in the rear yards between properties. Excavation was made possible at either end of the street, in the roadway or common areas to gain access to the pipe and avoid any excavation on private properties or driveways. We were also able to avoid the removal of boundary fencing and walls and the excavation of newly laid concrete driveways -- extensively landscaped areas.
Although no major incidents were encountered during construction, various unforeseen issues arose causing schedule changes on short notice. Due to the flexibility of the CuraFlo system and the cooperation of the city, crews worked to alter the lining lengths or amount of linings per day to reduce customer disruptions and maintain overall project scheduling.
The outcome.
This three-year multi-phased project has a completion target of October 2009. The City Council approved $1 million per year for 3 years. Based on historical in-house line replacement data and estimated per-foot costs from trenchless contractors, an average cost of $45 per foot was budgeted. As of January 2008, 24,800 feet of the estimated 68,000 feet has been completed.