Safeguarding the Water We Drink

By J. Gregory Gerdel

Photo by J. Gregory Gerdel.

Before the implementation of Montpelier’s Water Filtration Plant in June 2000, people not having screens on their taps would occasionally notice some flotsam and jetsam (bits of plant matter, usually) floating atop a settled pot of water. And those with screens on their taps would occasionally need to rinse that accumulation from the screen. While the Berlin Pond water, treated with chlorine, was safe to drink, aesthetics and palatability could have been better.

Jeff Wilson, chief operator of the team of three certified technicians at the plant on Paine Turnpike in Berlin, is charged with ensuring that the city’s tap water is safe and pleasant to drink—in other words, potable and palatable. The other longtime certified operators are Michael Farnham and George Hood.

Wilson was quick to urge the citywide boil-water notice in February when the rupture of a main at the intersection of Elm and Spring streets caused a significant pressure loss through most of the system. The protocol for calling a boil-water notice is established by the Vermont Drinking Water and Groundwater Protection Division. “Our mission is customer service. A risk of contamination comes with low pressure in the system,” Wilson explains, “and we are going to err on the side of caution.”

How Sampling Works

In the case of the unusual citywide notice in February, canceling the boil notice required sampling tap water at nearly a dozen locations throughout the city, the first time such broad sampling has been required since the opening of the filtration plant. Wilson says the sampling is planned in coordination with the state’s water protection division and testing is done by both the state lab and Endyne, a private lab in Williston.

Water samples are collected from the taps—with permission, of course—in buildings, including residences, at locations that will be representative of water quality throughout the system. It’s notable that the proactive response by the city has been successful: No samples have failed in the 18 years since the opening of the filtration plant.

About the Source

While the Berlin Pond source of Montpelier’s water has been the subject of controversy about recreational access, Wilson notes that the water treated at the plant is “moderately hard” and scores well for palatability, another standard of water quality that is maintained at the plant. The relatively high alkalinity of the water makes it comparatively easy to maintain the targeted pH of 7.6–7.8.  The system uses six to eight gallons of sodium hydroxide to adjust the 900,000 gallons of water processed, on average, each day, Wilson explained.

Montpelier’s water is very low in the problematic level of carcinogens found in some water sources around the state. The city has water analysis data available on request. “People are sometimes curious about the water the city provides, particularly if they are home brewers, growing plants, or maintaining an aquarium,” Wilson said.

Wilson has mixed feelings about the increased recreational access on Berlin Pond, which has increased the turbidity of the water coming into the plant. He notes that the turbidity has declined some after the initial rush of activity slacked, but it has required an increase in the frequency of the backwashing needed to clean the sand filters the plant uses at the beginning of the treatment process.

Point-of-Use Filters

If only because they improve the palatability of city water by removing the odor and taste of chlorine, point-of-use filters, such as Brita or PUR, are widely popular. In fact, water technicians note that chlorine will gas off from water in a relatively short time: “If you fill a quart jar with water, put it in the fridge for about 20 minutes, then put the lid on, the chlorine odor will have evaporated,” Wilson said. Of course, the carbon and resin filters in these devices remove toxins, but they are not designed to provide disinfection.

Tour the Plant

With advance notice (one week is preferred), the team of certified operators is pleased to provide tours of the facility. They have regularly hosted school groups, other water treatment professionals, and interested citizens. The best times are 9 am to 2 pm Tuesday through Thursday.

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