By Adam Davis
An event at the Rutland Recreation Community Center held last week by local and state officials and sparsely attended by the public outlined potential solutions to the rising levels of haloacetic acids in the city’s water supply.
The city is now looking to change how it will decontaminate its tap water as the recent study showed the water contains more haloacetic acid levels than are currently allowed under state regulations.
As more members were on the panel than public attendees, moderator and Alderman Joe Barbagallo strongly encouraged the public to attend the second meeting at the Recreation Center on Wednesday, Nov. 20, at 7 p.m.
City and state officials firmly pointed out that the city’s water is safe to drink and that the potentially harmful effects stemming from haloacetic acids, or HAA5, are only linked with long-term exposure. Haloacetic acids are carcinogenic at higher levels and are a common contaminant in disinfected drinking water. They form when the chlorine used to treat the water chemically reacts with other naturally occurring organic matter, such as dissolved plant material.
“If it wasn’t safe to drink, Josh [Gravelin, of the Vermont Department of Environmental Conservation’s Public Drinking Water Program, who also spoke at the event] would be calling me right away and issuing a ‘do not drink’ order,” said Tom Garofano, the chief operator of the city water plant.
Haloacetic acid levels were at an all-time low in 2011 after Tropical Storm Irene decimated Mendon Brook and its vegetation, which has been Rutland’s water source for over a century. As vegetation around the brook has grown back over the past 13 years, so have the higher concentrations of HAA5. The city tests the water at its most vulnerable areas based on the water’s age in its mains.
Rutland has typically tested above or below the state’s regulation limit but never for a long enough period to force any changes until now.
While the current slow sand filtration facility removes nearly all existing bacteria and other pathogens from the water source, a final disinfection process protects against the recurrence of bacteria as it flows throughout Rutland’s 70 miles of water mains.
State officials presented three potential solutions to counter the rising levels of HAA5. The first two options would require the city to build new filtration systems at a total cost of $10 million and $6 million, each with annual operating expenses of $400,000. The first is a granulated activated carbon filtration system or GAC, often used to remove various organic pollutants such as fuel oils, radon, PFAS, and others.
“Carbon is very effective at removing contaminants,” said city engineer Mark Youngstrom. “It would involve large vessels or tanks of activated carbon the water would pass through.”
The second option is an ion exchange process involving the filtered water flowing through tanks that absorb the organic compounds like GAC.
“It’s an extremely complex process. Picture a brewery or something like that; lots of stainless steel equipment, piping, and pumps,” Youngstrom said.
Both of these options would require additional testing, 24-hour operator attendance, 3-phase power to the site, and other additional facilities.
The city’s third and most cost-effective option is implementing chloramine disinfection in the water supply. This option involves injecting liquid ammonium sulfate (LAS) before the water is treated with chlorine. This combination forms monochloramine, a less reactive form of chlorine, and, therefore, has less risk of creating a byproduct such as HAA5. This solution would likely cost between $300,000 and $600,000 to construct and would only increase the facility’s annual operating costs by $20,000 per year.
Some of the few citizens who attended the first meeting raised concerns about the overall health effects of monochloramine in the water supply.
Youngstrom assured them that it’s an old but proven technology invented in Denver over a century ago and still used by most of the country’s largest public water systems, including Boston and New York City. Joe Duncan, the general manager of the Champlain Water District, said that they began using it in 2006 to treat water for their 83,000 customers. He pointed out that correct dosing of monochloramine is critical, and the district’s water system has become refined to the point where the Rutland system has won awards for having New England’s best-tasting water.
Also on hand was Bridget O’Brien, a toxicologist with the Vermont Dept. of Health, who further explained that monochloramine has been considered safe for some time.
“Monochloramine is a very well-studied chemical. As long as the system is running smoothly, that’s what’s going to come out. It really isn’t a toxic compound,” said O’Brien.
O’Brien went on to explain that reports of chloramine use in public pools that resulted in breathing problems and skin irritation were directly related to tri-chloramines, not monochloramines and that the risks associated with monochloramines were very rare.
