The adage 'if a little is great, then a lot must be better' has been the practice and a UW lakes scientist says that is having an impact on Northwoods water.
UW-Madison Limnologist Hilary Dugan is speaking next week at Nicolet College in Rhinelander about the use of road salt on winter roads. The talk is called "Salting Our Freshwater Lakes".
Dugan says the amount of sodium chloride...table salt...is steadily increasing in lakes.,,
"....in small quantities it is environmentally safe, but like many other things when we are using millions of tons of it every year, it becomes unhealthy for our environment...."
She says when the salt hits the water it dissolves into both sodium and chloride ions and they move through the ecosystem quickly. She says over time the chloride concentrations are increasing over time and eventually could reach the groundwater...
"...what we found was that almost all lakes near roads or parking lots are seeing higher chloride concentrations than what we would see naturally in a lake not close to a road....."
She says to date, the salt concentrations are not at critical levels, but the levels are stressing some ecosystems. But road salt is critical to keeping winter roads open and commerce flowing.
Dugan says there is a relatively easy fix...
"...this is a public safety issue. Salt is still one of the cheapest and most effective ways to have safe roads in the winter. We've just been using way too much road salt for too long. We've had 60 years of applications at volumes two to ten times the volume that is needed to be effective. If we just scale that back I think we'd see rapid improvement in a lot of aquatic ecosystems...."
Dugan is appearing as part of Nicolet College's Learning In Retirement Ced Vig Nature Series. She will give her presentation at 9:30 a.m., Wednesday April 4 at the Nicolet College Theater.
That same day, Dugan will also be appearing as part of Mincoqua Brewing Company's Science on Tap series. That event will start at 6:30 p.m. on Wednesday, April 4.
