United Water New Rochelle (UWNR) has over 400 miles of water mains serving a heavily populated area in Westchester County, just north of New York City. UWNR has embarked on a multi-year water main rehabilitation program to continue providing quality service to its customers. UWNR had a comprehensive study performed to evaluate the water main system needs. This study included computer modeling. The work was prioritized and scheduled according to the data developed by the study.
Buck, Seifert & Jost, Inc. (BS&J) designed the first two (2) contracts, which included cleaning and cement-mortar lining of existing cast iron water mains which had been in service for approximately 100 years. CONTRACT A included approximately 12,000 lineal feet of 8″ cast iron water main and CONTRACT B included approximately 4,700 lineal feet of 16″ cast iron water main. A recent flow test on these water mains indicated that tuberculation had reduced the “C” factor to approximately 60. Also, a sample of the water main was tested and was found to be structurally sound.
These projects are currently under construction and the resulting lined pipe will provide a “C” factor of approximately 120. Also, the cement-mortar lining will protect the pipe from further corrosion and tuberculation build-up, thereby providing many years of additional service at a quality approaching that of new piping but at a fraction of the cost.