Public water systems are regulated by the Massachusetts Department of Environmental Protection, and the federal Environmental Protection Agency.
​
According to the state, a public water system is one that “for the provision to the public of water for human consumption…the system has at least 15 service connections or regularly serves an average of 25 individuals daily at least 60 days (about 2 months) of the year.” - Mass.gov 
​
In addition to residential areas, public water systems also serve mobile home parks, apartments, daycare facilities, campgrounds, dining establishments, nursing homes, etc. The Holiday Inn, Boxborough, Heritage Country Club, Charlton, and Country Hills Plaza Mendon are a few examples of privately owned public water suppliers throughout central Massachusetts.
PUBLIC WATER SUPPLY
From River to Tap
In most cases, the reservoir providing your home's drinking water in a public water supply is miles away, pumped to you through a series of pipes (with gravity's help). Check out our interactive map of most public water suppliers in Massachusetts to see just how far some of this water travels.
The MWRA is the largest public water supplier in Massachusetts, and controls the 412 billion gallon Quabbin Reservoir. The Quabbin provides drinking water for 3 million Massachusetts residents in the Boston metro area. Learn more from the MWRA about how that water travels 65 miles from Belchertown to Boston >>
Other cities have their local reservoir systems too. For instance, Gloucester obtains its water from six reservoirs, and Cambridge uses four.
Water sitting in those reservoirs is treated before it is pumped to homes and businesses. Iron, manganese, organic material, algae, virus, and bacteria are all removed at this stage.
​
Like other systems, all water used within homes and businesses is considered wastewater and sent to a treatment plant in the same system before re-entering the ecosystem (rivers or the ocean) as clean water.
Who is Responsible for Maintaining Public Water Supplies?
The Safe Drinking Water Act was enacted by Congress in 1974 as a framework for public water regulation. The Environmental Protection Agency (EPA) creates additional provisions to guarantee safe, clean drinking water. The EPA requires annual water quality reports as one measure to ensure municipalities are adhering to its regulations.
MassDEP oversees more than 1,700 public water systems across the state in accordance with state Drinking Water Regulations. The Massachusetts Drinking Water Program and the MassDEP Drinking Water Regulations are the two primary rules and guidelines for public water systems. Water quantity falls under the MassDEP Water Management Act Program which regulates water withdrawals in Massachusetts. 
Effects on Water Cycle
Surface water (lakes, rivers, and streams) and groundwater, are both sources of drinking water. Almost 220,000 acres of protected land is used solely for the Commonwealth's drinking water supply. These conserved lands are shielded from construction, preserving water quality.
Aging water infrastructure statewide continues to threaten the stability of our water systems. The pipes, pumps and storage tanks that deliver water are among the oldest in the nation at some over 100 years old. As the infrastructure reaches the end of its useful life, pipes become vulnerable to erosion. Pipe erosion can introduce harmful contaminants such as lead that can negatively affect the health of anyone who uses water from those pipes.
This aging infrastructure needs to be updated. However, a 2012 Water Infrastructure Finance Commission Report found that Massachusetts had a $10.2 billion gap in resources for drinking water infrastructure (and an $11.2 billion Gap in resources for wastewater projects) over the next 20 years.
The Commission’s gap estimates include capital investment, repair and replacement, operations, maintenance and debt service. Estimates do not include the cost of evolving regulatory requirements or investments to accommodate economic growth; so these estimates are understate rather than overstate the Gap and the funding need. In the 10 years since this report came out, it's safe to say that our infrastructure needs remain about at that level with the infrastructure itself deteriorating.
​