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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Water Quality

Providence Water owns and operates a RI Department of Health certified Water Quality Laboratory which is located at the Philip J. Holton Water Purification Plant in Scituate, RI. The mission of this laboratory is to administer a water quality monitoring and quality control program to meet the ever expanding and evolving requirements of the Safe Drinking Water Act and to ensure a safe and potable water supply for all our customers.

The laboratory occupies approximately 800 sq. feet of space and is divided into three functional areas:

  1. Wet Chemistry Laboratory - Routine water chemistry examinations including electrochemical analysis and spectrophotometric procedures.
  2. Microbiology Laboratory - Microbiology enumerations involving selective media cultivation.
  3. Instrumentation Laboratory - Trace metal analysis and treatment chemical purity analysis.

The laboratory staff is comprised of Sanitarians, Lab Technicians, Chemists, and Microbiologists who collectively process over 800 water quality samples each and every month. The majority of the laboratory's testing efforts are concentrated among four main monitoring programs:

  1. Treatment Quality Assurance Monitoring Program:

    Chemical and bacteriological quality control testing of our water as it passes through the various stages of the treatment process. Monitored treatment stages are as follows:

    • Raw Water - Monitored for water quality changes and treatment chemical dosage requirements
    • Aerated Influent - Monitored for proper ferric sulfate coagulant addition
    • Mix Water - Monitored for proper mixing of coagulated influent, addition of quicklime corrosion inhibitor, and final treatment chemical dosage adjustments
    • Settled Water - Monitored to determine efficiency of sedimentation process and proper chlorine disinfectant addition
    • Filtered Water - Monitored to determine efficiency of filtration and proper chlorine residual concentration
    • Effluent Water - Monitored to determine potability of final product as per regulatory requirements
  2. Distribution System Quality Assurance Monitoring Program:

    Safe Drinking Water Act required monitoring intended to ensure the safety of our water after it has left the treatment plant and entered the transmission and distribution network of holding reservoirs and water mains. Forty-two water quality monitoring locations are routinely sampled for chemical and bacteriological testing. These locations include the interior and perimeter areas of our distribution system, wholesaler connections, and all water transmission reservoirs. Results of monitoring are reported to the RI Department of Health. See also Total Coliform Rule and Lead and Copper Rule.

  3. Watershed Water Quality Monitoring Program:

    Monthly, quarterly and annual chemical and bacteriological monitoring of thirty-five brooks, streams and reservoirs located within the Scituate watershed. Testing is conducted to identify water quality related issues and chart trends which may affect future treatment operations. A Source Water Assessment Program is being conducted by Providence Water and the RI Department of Health to identify all potential and known sources of pollution within the Scituate water basin. Upon completion, a full report will be made available to the public.

  4. SDWA Compliance Monitoring Program:

    Non-routine Safe Drinking Water Act compliance sampling and monitoring for regulations such as the Lead and Copper Rule, Disinfection By-Products Rule and the Unregulated Contaminant Monitoring Program.