Study looks at Sherman’s salty wells
SHERMAN — Using a winch, Gary Robbins lowered a probe 310 feet down the well at Sherman School.
Nearby, Meredith Metcalf sat on the grass and recorded water quality numbers every five feet, tracking a variety of measurements including conductivity, which indicates salt is present.
“We’re looking for a significant change,” said Robbins, a geology professor at the University of Connecticut, who is leading a study on Sherman’s wells.
So why is the water so salty?
The changes in conductivity might help researchers determine the answer.
For several years, water from wells in town was undrinkable because of high levels of sodium and chloride, which together create salt.
A sign has remained on the water fountain in town hall, advising people to not drink from it.
The salty wells resulted in $13,000 spent each year on bottled water at Sherman School and another $5,000 on maintenance for the school’s water, plumbing and heating systems because the salt has corroded the pipes, said First Selectmen Don Lowe.
“The salt is destroying the inner systems of the building,” Lowe said.
But relief could be coming. The ongoing study, for which Sherman residents allocated $60,000 in June, will explore why the salt is getting into the wells and recommend solutions.
It will examine a Sherman School well, the firehouse and senior center wells first and the town hall and another school well in a second phase.
Lowe said the well issue was first brought to the selectmen in 2015, when firefighters noticed the water tasted salty at the firehouse, but he said the problem could have been going on longer than that.
Higher levels of sodium can affect people who require low-salt diets. Too much salt can result in heart disease, high blood pressure and kidney disease.
More chloride is a taste or odor concern, rather than an actual health issue, said Lori Mathieu, who oversees drinking water for the state Department of Public Health.
“It’s displeasing,” she said, saying it tastes like pool water. “You’re not going to want to consume water at that level.”
The state limits on sodium is 100 milligrams per liter, and 250 milligrams per liter for chloride.
Of the five wells, only a well at Sherman School and one at town hall were within the limits in 2018. The limits were favorable in January and February, although the sodium in the school exceeded the limit in February.
The highest levels for 2018 were registered at the firehouse in May with 441 milligrams per liter for chloride and 181 milligrams per liter for sodium.
Mathieu and her team have met with Sherman officials to discuss their well situation and offered up the state lab for testing water samples, but isn’t taking a lead in the treatment. The department is working on a broader public information campaign, though that will launch this year, about how to protect wells and be more conscious about what is entering the groundwater.
“People don’t understand how important it is to protect the land casing of wellheads,” Mathieu said.
Why it’s happening
Officials are still unsure what’s causing the higher levels of sodium chloride in the wells, though the leading theory is salt from de-icing the roads.
“We seem to be using more and more salt,” Robbins said. “It’s very effective for saving lives, but unfortunately it gets into the groundwater.”
He said this isn’t the first time these spikes in conductivity, which show when salt is in the water, have happened. Levels increased in the 1950s, when the highway system was built, and jumped in the 1990s and in the last 10 years. These spikes can be attributed to a change in the salt-to-sand ratios for the road treatment, as well as officials just putting more down in some places.
Officials are still trying to find that balance between enough product to protect motorists in inclement weather and improving water quality.
Wells are fed by natural fractures in the bedrock. This is why it’s important to determine where the fractures are and note changes in water quality throughout the well before and after pumping so the source of the salt can be identified and a solution created.
The depth and angle of the fractures are more important than the type of bedrock itself, Robbins said, adding that Connecticut has a variety of rocks.
Preliminary findings from the work early this month suggest the salt is entering through fractures near the top of the well at Sherman School. This is evident because the water quality numbers are pretty consistent throughout the well, Robbins said.
Generally wells with shallow fractures are more vulnerable to salt and other contaminants entering from the land. Deeper fractures give the water more of a chance to be diluted by the time it enters the well, Robbins said.
The water table for this well also starts at about the same level as the paved driveway at the school, which would make it easier for salt to get in.
The well itself is weak, and had a casing placed in it when it was drilled to stabilize the weathered rock.
Many wells across the state have high salt levels, especially those along major roads.
Though the problem is not unique to Sherman, there does seem to be more salt than other spots.
“What we’re seeing in here is higher than most wells,” said Edwin Romanowicz, director of the Center for Earth and Environmental Science at the State University of New York, Plattsburgh, who is helping find the bedrock fractures in Sherman.
Many towns are looking to Sherman as a pilot to see if the steps taken in the town could be applied across the state.
“We’re kind of a leader on this in many ways,” Lowe said.
“The same concepts can be applied to other wells,” he said.
This study and more frequent sampling is already a step in the right direction, Mathieu said.
“We’re going to look at what’s going on there,” she said. “And if they have findings that can help other towns, and I suspect they will, they can learn.”
Lowe has reduced the salt put down on roads and parking lots near the wells, while still ensuring safety.
He’s hoping the state Department of Transportation might do the same on its roads.
“That’ll take some cooperation with the state, but I’m hopeful they’ll work with me,” Lowe said.
Mathieu cautioned that it’s not a one-to-one ratio, though, for reducing the road product and the resulting water quality numbers.
“It’s not a simple thing,” she said.
The action for the wells themselves will be determined after suggestions are presented in the final report. This could be a new casing at the top of the well if the fractures are shallow or putting concrete at the bottom if the salt is entering the well deeper down.
“I’m just delighted that the citizens of Sherman were forward-thinking to spend this money to remediate this water issue,” Lowe said. “My hat’s off to them.”