The Warren Sanitary District’s 244,200 GPD ultraviolet disinfection wastewater treatment plant in Warren, Maine uses new technologies to operate as cost-effectively and efficiently as possible. The plant’s facultative lagoons are designed and operated to combine anaerobic, anoxic, and aerobic biological processes for effective operations and to reduce energy use and sludge production. Baffles and a recycle pump station in the primary lagoon further enhance process efficiency.

The sewage treatment system includes three pump stations and over 10 miles of collection system.

A dissolved air flotation system removes algae prior to disinfection and makes the effluent quality less susceptible to seasonal variations typical in lagoon systems. Woodard & Curran has operated the plant since 1991.

Thus far operations have been very successful.

Designed to take advantage of innovative developments in facultative lagoon and disinfection technology, the facility also blended funding sources to create low and stable user charges for users within the Warren Sewer District.

The use of the latest ultraviolet disinfection technology in the disinfection system was chosen due to advantages in the areas of safety, ease of operation, and the elimination of disinfection by-products and has proven very successful. Ongoing evaluation and monitoring by operations staff generates useful information shared with Maine DEP, other regional treatment plants, and even national journals and associations to expand the body of knowledge surrounding this application of synergistic technologies.