Road salt in water: It’s a worry

Are we systematically despoiling our own drinking water?

The routine use of salt as a melting-agent on roads in winter was decried by a well-driller at a recent Board of Selectmen’s meeting, prompting board members to wonder if the practice should be reconsidered — though there appear to be no good substitutes or easy alternative solutions.

“Every town truck is a killer,” said well driller Henry Boyd. “… salt water.”

Salt put on roads in winter ends up in groundwater, he said, threatening the quality of wells people rely on.

“There is no natural purification for salt, when all that salt is in the ground,” Boyd said. “Everybody here has a well.”

Board members didn’t take action, but their interest was peaked.

“I think we should have a discussion about salting our roads,” said Selectwoman Maureen Kozlark.

“Is there an alternative?” asked Selectman Steve Zemo.

“Straight sand,” said First Selectman Rudy Marconi. “It doesn’t melt anything.”

Using salt rather than sand on roads promotes melting. Regular salt lowers the freezing point from 32 degrees Fahrenheit to about 24 or 26 degrees, Marconi said, and the salt product the town uses now — with a molasses-based additive — lowers the freezing point to about 17 degrees.

Instead of ice formulating at 32 degrees, it forms around 25 degrees. Fewer truck runs are needed.

“It’s allowed us save some money,” Marconi said.

“At the cost of contaminating our water,” added Zemo.

Marconi, who gets the phone calls, was skeptical.

“The residents will not like this at all. They want to see pavement,” Marconi said. “For us to make a decision without any support from environmental organizations is going to be a tough argument.”

Marconi later acknowledged the well driller’s point.

“You look at the amount of salt that’s on our state roads and local roads, that is being fed into our aquifers,” he said. “Our aquifers are the filtration beds for all of our drainage. Eventually, what we are doing is inevitably going to have a negative impact on the quality of our water.”

But road salt works.

“We used to use sand for traction and our roads were ice-packed, but sand was put down along with the use of chains for traction in the winters. With the introduction of salt we then went to a sand-salt mixture, which gave a benefit of both products, the sand for traction and the salt for melting,” Marconi said.

“And finally, today, we are using straight salt treated with a by-product for the molasses process, that allows our roads to become bare in a very short period of time. In essence we are pre-empting mother nature.

“The question is: This process, is it hurting and will it have a negative impact on the quality of our drinking water?

“So, we have a choice: Do we allow our roads to become ice-packed? Do we continue to monitor our wetlands, our aquifers, to benchmark them? Or do we find another product, and hopefully the latter is what will happen. Unfortunately, this product is not available today.”

Marconi thought the town could study the environmental effects.

“We could probably, in some of our concentrated areas of discharge from our roads, do some soil testing once every two years, to see what the salt content is,” he said. “It may not be bad to begin thinking about how we can monitor the potential negative impact on our drinking water.”


For Aquarion Water Company, supplying 3,300 households and businesses in Ridgefield, road salt isn’t a major problem — but it’s a concern.

“It hasn’t been an issue for us,” said Aquarion spokesman Peter Fazekas. “We have a source protection program in place, which is probably why is it isn’t an issue for us.”

Most Ridgefield customers get water from Aquarion’s system of reservoirs — Hemlocks Reservoir in Fairfield, Aspetuck Reservoir in Easton, Saugatuck Reservoice in Weston and Redding — which are connected to Aquarion’s “greater Bridgeport system” with five other reservoirs in Easton and Shelton. With storage capacity of close to 19.5 billion gallons of water, the system also draws from the Oscaleta, North Street and Beechwood wells in Ridgefield and the Canal Street and Coleytown wells in Westport.

Fazekas said Aquarion works with towns and the state to assure road salt is properly stored, limit the use of salt near reservoirs, and limit land development in watersheds.

“Our source protection program monitors land use in the watershed area, and it also monitors salt piles to make sure they are adequately protected from runoff,” Fazekas said.

“We’re checking to make sure they’re covered and protected, to avoid runoff. We definitely work with the towns on this.”

Aquarion limits the state’s spraying of roads with a saltwater mixture.

“We do have an agreement with CT DOT not to spray the roads along our reservoirs,” Fazekas said. “It does require continuous education. The spraying is sub-contracted, so contractors are always changing.”

And Aquarion monitors the water quality.

“We have not seen a significant increase over the last several years, as far as sodium levels in our water supplies,” Fazekas said.


Conservation Commission member Tim Bishop, a working environmental consultant for over 15 years, has studied long- and short-term road salt studies in Lewisboro and Putnam Valley towns in New York.

One study for the New York State Department of Health (NYSDOH) has gone on almost 15 years. “The water is so undrinkable, the town has been provided bottled water to over 20 homes over that period,” Bishop said.

“My experience with road salt monitoring and sampling at these two ‘case studies’ was that both sodium chloride plumes (the affected areas) were directly related to the frequency and volume of road salt being applied to the roads during winter months and/or improper storage of historic salt stockpiles,” Bishop said.

During rain, or snow melt, “highly concentrated runoff washes off of the roads” and into “fractured bedrock,” he said.

“Both sites (and Ridgefield would be similar based on the geology) were similar in that private drinking water wells were located close to the road and if they weren't, they were geologically connected to the impacted aquifer,” he said.

“Sodium and chloride concentrations were elevated well over the NYSDOH standards and hazardous to people with heart of other health concerns or salt-restricted diets. Highly saline water is also very damaging to home infrastructure such as submersible well pumps and internal plumbing and appliances … Residents I spoke with every three months when I went into each house would go through appliances almost annually.”

Road salt is “a difficult issue,” he said.  

“We have residents’ private drinking water and human health on one side, and driver safety and general commerce/business on the other … Costs are usually the driving factor of local or state governments. It's difficult enough to drive to/from work or (for) personal reasons in the winter with road salt, without it can be even more challenging or impossible.”

UConn professor

Michael Dietz, Ph.D, from the University of Connecticut, is a water resources educator and director of the Connecticut Institute of Water Resources.

He’s looked at water contamination with road salt.

“It’s big problem,” he said.

“There’s over 400 sites across the state that had levels of chloride above the state drinking water standard,” he said.

The big issue is corrosion, but it does have health implications.

“It’s not like other things, that are known to cause cancer, where that level is set for a health reasons. This level was set primarily for corrosion of pipes and taste in the water,” he said,

“It can destroy your hot water heater, erode yor plumbing...

“At high enough level it would be toxic, but we’re unlike to see it at those levels in groundwater,” he said.

Still, there are serious concerns.

“The issue that can come up — this happened in Flint, Michigan, — when you have high concentrations of chloride, it can leach other things out of the plumbing.”

In Flint, “it was lead” that leached out of pipes, he said.

To save money the hard-pressed city of Flint switched from buying Detroit city water to pumping water from the highly polluted Flint River, and failed to treat it with corrosion inhibitors.

The untreated water created a health crisis because lead leached from pipes into the drinking water. Lead is a neurotoxin that in high concentrations can cause serious health problems, especially for young children.

Salt — sodium chloride — can results in contamination plumes of both its components.

“The sodium also becomes an issue for hypertension,” Dietz said.

People worried about their water can take action.

“I’d recommend to get your water tested,” said Dietz. “The DPH (Department of Public Health) has a list of labs across the state that do a basic potability test, and that would include sodium and chloride in that test.

“If you have a shallow well, that’s especially vulnerable to road salt runoff from the street. But if you have a drilled well, that can also be high (in sodium and chloride) as well...

“It is a big issue, the salt running off the roads,” Dietz said. “It’s a broader issue than just Connecticut. It’s regional — all the northern parts of the country. Anywhere road salt it is used on the roads, it runs off into the streams. And it runs off the surfaces into the soil, too. It goes into the groundwater that way.

“It’s entering our surface water and our groundwater,” Professor Dietz said..

“There are impacts to aquatic life, there are impacts to vegetation, and to drinking water.

“I don’t have a magic bullet that can solve this. The main thing is to reduce the amount of salt that gets placed on the roads.

“There are programs in New Hampshire, and we’re trying to adapt this to Connecticut, training people in how to more efficiently apply salt.,” Dietz said.

A pilot training program is planned this summer at UConn in Storrs, to eventually be followed by programs around the state.

“The goal is to have the public works guys to come — it’s a day or two long — and learn how salt works, how to more efficiently apply it and still keep people safe,” Dietz said.

“Cutting down on the application is the only way to address this problem. There no way to get it out of the water after.”

If well water is contaminated, homeowners can get “reverse osmosis” filtration systems that would clean the water at point of use, but “the systems are expensive,” he said, and the groundwater remains polluted.

Highway department

Public Works Director Peter Hill, who oversees RIdgefield’s Highway Department operations, says it wouldn’t be easy to stop using salt on the roads.

“Until there’s something else out there that’s going to melt ice and make the roads safe, I think we’ll be using salt,” he said.

“When we were using a sand and salt mixture, each truck would have to put out four loads to cover their route. Now each route, we do it with one load, with salt. There’s a big difference there, because of the trucks having to empty out, sit in line, get loaded, they do that four times.”

There are other advantages to not having sand in the mix.

“We don’t fill the catch basins up. We’re not contaminating the streams,” he said.

“People used to complain about ponds being filled in with the siltation with the sand washing into the ponds and streams. And that doesn’t happen anymore — we’re not using sand.

“There used to be a big dust issue around the schools because of all the sand dust, but we’re not using the sand any more,” Hill said.

“We can sweep the whole town with one sweeper. Where we used to have to rent out a gang of sweepers.”

“The salt makes a big difference all the way around.”

Hill said he doesn’t dispute well driller Henry Boyd’s argument that there may be long-term environmental concerns.

“I’m not going to argue his point, he might have a point,” Hill said. “Right now, my concern is making roads safe for travel.”