The Department's oversight of investor-owned water companies is based on G.L. c. 165, § 1 , which defines a water corporation or company as "every person, partnership, association or corporation, other than a municipal corporation, and other than a landlord supplying his tenant, engaged in the distribution and sale of water in the Commonwealth through its pipes or mains." In Massachusetts, Department-regulated water systems range from large corporations supplying thousands of customers to small systems supplying a few residences. There is no minimum size requirement for an investor-owned water system to be subject to the Department's oversight.

Most water systems in Massachusetts are owned by cities and towns. Because these water systems constitute municipal corporations as defined by G.L. c. 165, § 1 , the Department does not regulate these systems. Any dispute between a customer and a municipally-owned water system would have to be addressed by that water system.

Water and fire districts are self-governing districts created by special acts of the General Court. Water and fire districts are generally not subject to Department jurisdiction, unless otherwise specified in the district's enabling act. For example, the district's enabling legislation may provide that an intermunicipality price dispute may be brought to the Department for resolution. Water and fire districts are required to file their rates for informational purposes only pursuant to G.L. c. 165, § 2A.

There are a number of homeowner associations in Massachusetts that provide water service. Some associations are organized as nonprofit corporations, while others may operate on a more informal basis. The Department does not exercise jurisdiction over these water systems, provided all customers are members of the association. In cases where a water association is supplying non-member customers, the Department limits its jurisdiction to only those non-member customers.

This information is provided by the Department of Public Utilities