Water department celebrates completion of treatment plant upgrade with open house

LACONIA — The Laconia Water Department held an open house Saturday morning at its treatment plant off from Stark Street marking the completion of its first major improvement to the facility since it was constructed in 1989.

Superintendent Seth Nuttelman said that improvements included replacement of filters and valves as well as enhancement of the electrical and SCADA (Supervisory Control and Data Acquisition) system at the plant.

The plant has three identical filter units, or trains, each capable of processing between 1,200 and 1,500 gallons of water per minute. Each train consists of a clarifier, which removes 80 percent of unwanted particles, and mixed media filers, containing coal, silica and sand, which polishes the water to remove the remaining particles. The materials were removed from the trains, which were sand blasted and painted before being replenished with fresh materials.

The city's water is drawn from Paugus Bay and pumped up the hill to the treatment facility by two vertical turbine pumps, each powered by 300 horsepower motors and each of which pumps around 4,000 gallons a minute.

When the water reaches the treatment facility the incoming water goes through a static mixer where alum (a coagulant) and chlorine (a disinfectant) are injected. It then flows to one of three trains.

The processed water passes from filters to a 180,000 gallon baffled clear well under the floor where it is treated with sodium hypochlorite for post chlorination, sodium hydroxide for pH adjustment and sodium fluoride for dental care.

The finished water is then pumped from the clear well to two storage tanks at the site, one holding 2 million gallons and another holding 1.3 million gallons. Other holding tanks in the system to meet customer demand and provide fire protection include Briarcrest, 690,000 gallons, and Long Bay, Weirs, Endicott and Lighthouse, all holding 500,000 gallons.

Nuttelman and Water Commission Chairman Greg Page said that the project took three years from start to finish. Originally estimated to cost $1.5 million, the work was undertaken primarily by the staff of the department, which Nuttelman said saved "at least $500,000".

He credited Jason Bordeau and Floyd Dungellman of the department with designing and fabricating an important part of the upgrade which allow the department to recover 95 percent of the water it uses to backwash the filter system twice day and which would have gone to the wastewater treatment plant in Franklin.

"The water has turbidity and is cloudy with suspended particles. But now we're able to recycle it by pumping the water from our waste tank back to the beginning of the system," says Nuttelman.