Bangor Water

Article Title: Treating and Testing

Article Content


Since 1959, Floods Pond in Otis has been the source of supply for Bangor Water.   Because the pond is so protected and clean

  • It does not need to be filtered
  • It requires minimal treatment

The disinfection process is two-part:

  • Ozone/ultraviolet light disinfection systems are used on the untreated water
  • Chloramines are added to maintain the “disinfected state” as water travels into the 200 miles of water mains  in our distribution system

The treatment process finishes with

  • pH adjustment for corrosion control
  • fluoride for dental health (0.70 mg/L – lowest level recommended by the CDC)

In 2017, the drinking water met or surpassed all state and federal drinking water quality requirements. Thanks to the pristine nature of Floods Pond, very few regulated compounds are found in the water before or after it is treated, and many are naturally occurring at low detection levels.


We have maintained our Exemption to Filtration for 25 years. There are fewer than 60 unfiltered systems in the United States, and eight–including Floods Pond–are in Maine. In comparison, filtration is required for the approximate 12,500 surface water supplies across the nation.

A large part of the exemption is due to the well-protected nature of Floods Pond.  Bangor water owns or protects 99 percent of acreage within the watershed, including conservation or protective easements for land not owned outright.

  • Gated access helps protect the area within the watershed boundary.  It provides security for our facilities, and minimizes erosion caused by vehicular traffic.
  • There is no boating or swimming on the pond; that minimizes bodily contact with drinking water, gasoline spills from boats, invasive plants.
  • There are no buildings other than Bangor Water facilities within the watershed; that eliminates industrial toxins, runoff from pesticides and fertilizers, and domestic livestock as carriers for contamination.

Being unfiltered has saved ratepayers significantly over the years. The estimated cost for a filtration plant 25 years ago was $30,000,000, and annual operating costs would have required additional monies. The source water protection plan we have for Floods Pond allows us to receive additional waivers as appropriate.

We undergo an annual watershed survey by the State of Maine to ensure that we continue to meet all criteria for an unfiltered public water system.


Testing the water we deliver to you is an ongoing daily part of ensuring water quality, and we’re required to test for more than 120 contaminants with known health effects.  We draw samples every work day from

  • Approved sampling locations throughout our distribution area
  • The last stop in the treatment process in our facilities at Floods Pond
  • Floods Pond before the water makes its way into the treatment process

We typically pull between 2,400-2,500 samples annually, and since multiple tests are performed on each sample, we check more than 11,000 sets of results every year.

Bangor Water maintains a certified lab; that means training personnel, performing quality assurance testing, having the facilities inspected by the state, and following detailed “standard operating procedures.”

  • We test only our samples and those of other local water utilities.  We’re certified for bacteria and certain chemical analysis.  We’re not a public lab.
  • We’re not certified for complicated tests, such as testing for lead. These we send to qualified labs for analysis.
  • We test more samples than we are required to by the State to get more information about our water system.