Each water corporation shall make reasonable efforts to prevent interruptions of service. When interruption occurs, the water corporation shall reestablish service within the shortest possible time period consistent with the general safety and public welfare. Whenever service is to be interrupted for the purpose of scheduled maintenance, this work shall be done at a time which will cause the least inconvenience to customers provided that the schedule is compatible with local ordinances and does not result in substantial additional costs.

A record shall be kept by each water corporation of all interruptions to service having a duration of one hour or more, from any cause whatsoever, except those resulting from violation of the company's filed tariff regulations or customer-requested disconnections. Such records shall describe the nature, location, time, cause, extent and duration of the interruption. A record of that information shall be open for public as well as department inspection during the water corporation's normal business hours. Each water corporation shall immediately notify the fire department of each municipality affected, and upon written request of the municipality concerned the police department as well, of existing and/or proposed interruptions to service which may affect the continuity of service to fire flows for a period of one hour or longer. Where planned interruptions in water service, which are likely to exceed one hour in duration are anticipated, all customers who will be affected thereby shall be notified at least four hours in advance to permit them to prepare for the interruption in water service. As used in this section, a planned interruption is any interruption of which the company has prior knowledge and which has an anticipated time and duration. This would normally include all interruptions which are not of an emergency nature. Immediate notice by telephone or telefacsimile shall be given to the department by each water corporation of all interruptions to, or major impairments of, service of a duration of four hours or more which affect the continuity of service to five or more customers or one percent of the total number of customers served, whichever is larger, or which affect available fire flows. Notice shall also be given of any accident or damage to portions of the plant which might lead to such interruptions of service. If such interruption occurs after 4:45 p.m. and before 8:30 a.m., and notice is to be transmitted by telephone, such notice shall be given promptly on the next business day following the interruption. A written report of all such interruptions shall be filed with the department within five business days following that in which the interruption occurred.