Providence Water, although a department of the City of Providence, is regulated by state and federal agencies in addition to city policies and procedures. The quality of our treated drinking water is regulated by the US Environmental Protection Agency and the Rhode Island Department of Health. Our revenue and rate structure is regulated by the Rhode Island Public Utilities Commission.

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Alum Treatment

A recent scientific assessment has shown that Providence Water’s Moswansicut Reservoir, a tributary to the main Scituate Reservoir, is showing signs of stress or degrading water quality. The Moswansicut Reservoir is located in the northeast corner of the Scituate Reservoir watershed near North Scituate village and along the Scituate-Johnston town line.

The water quality issue is caused by high levels of phosphorus being constantly cycled and recycled within the reservoir. Excess phosphorus is problematic because it provides nutrients leading to bacteria growth. Some of these bacteria can be harmful to humans. The solution is to trap or encapsulate the phosphorus on the bottom of the reservoir where it is unavailable to the bacteria. This result is best achieved by applying a chemical compound commonly known as alum (aluminum sulfate) to the water.

Providence Water has hired a contractor to apply alum to the Moswansicut Reservoir this spring. The firm, HAB Aquatic Solutions of Lincoln, Nebraska, will conduct the treatment. Their work will include the use of sophisticated in-reservoir instrumentation and all activities will be closely monitored by Providence Water staff and a third party consultant.

Our longstanding watershed protection efforts will continue in order to minimize the amount of phosphorus entering the reservoir through brooks and streams and direct runoff. These efforts include:

  • Acquiring land and conservation easements
  • Educating nearby landowners
  • Providing testimony at local planning and zoning boards
  • Monitoring water quality samples from brooks and streams
  • Managing the woodlands around the reservoirs in ways that minimize runoff
  • Enforcing our “No Unauthorized Access” policy.

More detailed information and updates on the Moswansicut Reservoir alum treatment are available on a project website provided by HAB Aquatic Solutions: