AWWA INF53963

In 1997, an engineering team consisting primarily of Montgomery Watson andParsons Brinckerhoff Quade & Douglas, Inc. began a pipeline rehabilitationproject in the Boston area for the Massachusetts Water Resources Authority. Theproject involves the inspection, evaluation, and rehabilitation of approximately100,000 feet of 48 and 60-inch diameter pipelines, mostly made up of gray cast iron pipes. These pipes, known as the East and West Spot Pond Water Supply Mainswere installed between 1896 and 1902. Over the years, these pipes have providedreliable service to eight communities in and around Boston. The purpose of theproject is to provide measures to ensure continued reliable service, improvedhydraulic performance and protect water quality, and if possible, extend theuseful life of the facilities by 50 years. Methods used to evaluate the pipecondition included soil borings, vacuum excavations, test pits, ultrasonicthickness measurements, and materials testing. A structural evaluation of thegray cast iron pipes established the extent of rehabilitation needed to achievethe project goals. The analysis revealed that the gray cast iron pipe was in goodcondition after 100 years of service and that with minimal rehabilitation effort,it should provide another 50 years of service. At present approximately 20percent of the rehabilitation contracts have been awarded. Includes tables, figure.