In New England, most of the water main networks first went into service in the early 1900’s. In many municipalities, this water main is still providing service today; even after a century of use. However, cast iron water main installed prior to 1950 almost always was installed without an internal cement coating to prevent internal corrosion. Corrosion of the internal cast iron surface results in formation of turbicules of iron oxide that reduces the effective diameter of these pipes. In most New England water systems with typical low hardness and low alkalinity water, the old unlined cast iron pipe can now only carry about 40% of what a new pipe of the same diameter can carry. In some cases, replacement is warranted but in many cases, these pipes can be returned to service at costs much less than replacement using cleaning and lining techniques. With the financial challenges facing water customers, every option for meeting regulations at the lowest lifecycle cost must be evaluated.
An invaluable tool in the assessment of water distribution systems is the water system computer model. Dufresne Group owns and maintains several different types of models for this analysis including WaterGEMS® that interfaces with GIS based mapping and database management systems. Dufresne Group has completed water models for over twenty New England Communities.