Joe's Lawn and Snow service uses half as much salt as it used to. The University of Minnesota cut its salt use by 41 percent, and the city of Waconia by a whopping 70 percent — all without sacrificing safety for drivers and pedestrians.
As fish-killing chloride continues to rise in Twin Cities lakes, streams and groundwater, many communities are finding that they can do more to balance public risk on streets and sidewalks with the ecological damage caused by winter applications of road salt — while saving money at the same time.
In a new economic analysis, the Minnesota Pollution Control Agency says that just a 10 percent reduction in application would save metro area cities and counties at least 35,000 tons of salt and $8 million a year in winter maintenance — along with one or two lakes.
That doesn't include the tens of millions of dollars spent to fix salt damage to roads, bridges, cars and lawns.
But judging by the increasing number of lakes that are contaminated by chloride, there is still a long way to go, said Brooke Asleson, chloride project manager at the MPCA.
"The water quality suggests we have a lot of work to do," she said.
Some 40 lakes, streams and wetlands in the Twin Cities are contaminated with chloride, and that number is expected to rise when the state completes its assessment of another 38 targets later this year.
And after decades of winter salt use, now even groundwater is contaminated. Thirty percent of state monitoring wells in the Twin Cities exceed the standard established to protect aquatic life, and 27 percent are above the level set to protect the taste of drinking water.
Most of the metro area's drinking water comes from much deeper aquifers, but it's a warning sign that as salt spreads through the environment, eventually salty water could be coming out of the tap in many homes, Asleson said.
It's already happening in Madison, Wis., where a city well that supplies 10,000 people is so contaminated that residents are complaining about salty-tasting water.
Lasting pollution
Unlike many other pollutants, which eventually break down or end up in the Mississippi River and the Gulf of Mexico, chloride stays in the watershed indefinitely. One teaspoon is enough to permanently pollute 5 gallons of water.
In a Midwestern winter, however, salt de-icing of roads is what drives modern urban life.
"It's difficult," said Diane Spector, water resource planner for the Shingle Creek Watershed District on the northwest side of the metro area.
"Unlike some other pollutants, this is a public health and safety issue. It's a tough reduction to try to achieve."
In the drainage area for two Twin Cities streams that are contaminated — Shingle Creek and Nine Mile Creek — salt use would have to come down by 62 percent or more to improve conditions for everything from aquatic insects on up to fish.
Nevertheless, there has been some remarkable progress, from the smallest operators up to the Minnesota Department of Transportation, the state's largest salt user.
For Joe Mather, owner of Joe's Lawn and Snow in south Minneapolis, the simplest tool proved to be critical — a hand-held salt shaker that he found in a hardware store.
Mather removes snow for about 120 customers, and the shakers distribute salt only where it needs to be, he said. Now he buys them by the case.
"That salt shaker thing has been a miracle," he said.
He and his employees have all participated in the "smart salting" training the MPCA provides to operators. He's also invested in road surface thermometer guns so he knows what kind of salt to use; he calibrates the spreaders on his trucks, and even installed a $600 light on the back so he can see how much salt he's using and where it goes.
So far he's cut his salt use in half — and saved his business about $10,000 per year.
Chris Link, street operations manager for the city of Richfield, at first thought it would be impossible to cut salt use enough to protect Nine Mile Creek. But after training the staff, investing in calibration equipment and adopting a standard practice of pre-treating city roads with brine before a storm, the city has reduced its salt by half.
Driver resistance
The biggest barrier to reducing salt use could be public attitudes, according to environmental and municipal officials.
"Whether I like it or not, we are living in an age of ever increasing impatience by motorists," said Mark Maloney, operations director for the city of Shoreview, which has changed its salting practices.
While major county roads and interstate highways may require bare pavement for safety reasons, it's not necessary for residential and local streets, Maloney said. "But [some drivers] think they are entitled to it. It's hard to have a rational discussion with people about it," he said.
Mather said most of his customers are "floored" when he explains the relationship between de-icing and water pollution, and most are happy if he uses the minimum salt necessary, he said.
But there are those who just don't care, he said. One customer insisted that Mather apply more and more salt to a parking lot in order to get the "biggest bang for the buck," he said.
"I told him it didn't work that way," but the customer wouldn't listen, Mather said. "So I dropped that account."
Josephine Marcotty • 612-673-7394
