John Garver kneels on a rock in the middle of the woodsy creek that runs through the Union College campus and lowers a syringe, drawing water into the plastic device.
When he's done, he transfers the water into a plastic tube and brings it back to his office for further study.
This isn't the first time that Garver, a Union College geology professor, has visited the Schenectady creek, known as the Hans Groot Kill.
He's been taking samples from the creek since last May, with the goal of learning more about the stream's overall water quality. This month, his focus is salt. And while he hasn't analyzed his results yet, he suspects that the creek's salt content will be high.
That's a problem, because salt can be enormously damaging.
It can alter the ecosystems of rivers and streams, making them less habitable for the freshwater species that inhabit them, speed the corrosion of bridges, roads and other infrastructure and threaten drinking water.
The amount of salt - chloride and sodium - in the Mohawk River has increased dramatically in recent decades, a trend driven by heavy use of road salt in the winter.
Last month, Garver wrote a widely circulated blog post on his website, "Notes From a Watershed - the Mohawk River," aimed at raising awareness of the problems posed by road salt in freshwater rivers and streams.
The post draws upon research from a wide range of sources, such as the U.S. Geological Survey and a group of Union College students who measured the salt content of local rivers as part of a thesis project.
Above all, the piece makes it clear that the prodigious use of road salt comes with consequences.
"The environmental cost of this regional salinization is profound," Garver wrote. "There is no question that road salt saves lives and reduces accidents. But the environmental cost appears to be enormous and I sense we are nearing a tipping point."
In his blog post, Garver estimates that the Mohawk River's chloride levels have risen over 300 percent since the early 1950s - an alarming finding that raises real questions about whether we're oversalting our roads and what, if anything, should be done about it.
Garver has long been an advocate for the Mohawk River.
He organizes an annual conference, the Mohawk Watershed Symposium, focused on issues related to the river, such as water quality and flooding. Road salt in the watershed is a relatively new topic for him, but one he believes merits more attention.
"A clean, healthy river is something we should all want," Garver told me. "And salt is part of the equation."
Of particular concern is the fact that Mohawk Watershed's salt content is high year-round, not just during the colder months when road salt is being applied.
This suggests that there's salt in both the surface water - the rivers and lakes we can see with our eyes - but also the groundwater found in the cracks and spaces in soil, sand and rock.
Mason Stahl, an assistant professor of environmental engineering at Union College, supervised a group of Union College students who studied the water quality in the Mohawk Watershed.
They found that sodium and chloride are increasing in the watershed, and that the elevated salt levels observed in spring, summer and fall is likely caused by contaminated groundwater seeping into rivers and streams.
"It will take many years to flush that (sodium and chloride) from the system," Stahl told me.
Like Garver, Stahl believes it's time to consider ways to reduce road salt use.
"We're not going to stop using road salt," he said. "But can we apply it more efficiently than it's being applied? Can we optimize its use?"
It's a good question.
Personally, I'd like to see us try to use road salt more judiciously, and to consider other methods of clearing the roads in the winter. There are alternatives to road salt. Live-edge plow blades do a better job of removing snow and ice from the roads.
Keeping the roads safe is important, but so is protecting the Mohawk River.
I'd like to think we can do both.
Reach Sara Foss at [email protected]