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Photo of Josiah Chase Water Filtration Plant in York, ME.


The Josiah Chase Water Filtration Plant (JCWFP) started producing drinking water in mid-1990. It was designed to produce a maximum of 4 million gallons (at 2,800 gallons per minute) of treated water per day that meets or exceeds US EPA Primary and Secondary drinking water standards. The standards are health-based (known as Primary) and aesthetic quality (Secondary: appearance and taste). 

There are other requirements and guidelines for the treatment methods used. Guidelines are meant to ensure optimum treatment performance and comply with requirements under other EPA programs. 

These programs include, “Surface Water Treatment Rule,” “Disinfection Byproduct Rule,” “Lead and Copper Rule,” among others.

The treatment process at JCWFP is known as “Direct Filtration.” This process consists of a series of multiple treatment techniques. It was chosen specifically based on treating the water quality at Chases Pond.

The various treatment unit processes consist of:


•    Aeration/circulation
•    Straining
•    Pretreatment (when needed)
•    Coagulation and Flocculation
•    Clarification
•    Filtration
•    Primary Disinfection
•    Corrosion Control
•    Secondary Disinfection


Finally, water is sent out to our customers—Distribution.

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