County road crews have dumped more than 195,000 tons of salt on central Wisconsin highways over the past five years, with much of it running off into nearby water systems.

The chloride from the salt is particularly toxic for wildlife, plant life, pets and humans.

Those who oversee county highway departments say they're quite aware of those dangers, and it's why they're increasingly using less-harmful materials to clear the roads for motorists.

Marathon County used about 90,700 tons of salt for state and county highways in the past five years — equivalent to 1,300 pounds of salt for every man, woman and child in the county — but has been using more brine as an alternative each year, said Russ Graveen, maintenance supervisor.

Brine is a mixture of salt and water or other liquid that is sprayed on the road. The liquid causes the salt to stick to the road and stay in place to do its job, rather than bounce to the shoulders and ditches.

Wood County also plans to convert from a mostly salt to a salt-brine system, local Highway Commissioner Doug Passineau said. Wood County has used about 42,500 tons of salt during the past five years. The county has ordered a 40,000-gallon tanker to make the switch to mostly brine, Passineau said.

The county now uses tanks on plow trucks to pre-wet the pavement for salt. When the temperatures drop below 12 to 15 degrees, the county changes to beet juice or a calcium-chloride mixture for the brine, which allows the solution to work at a lower temperature and reduces the amount of salt the plows are spreading.

"The county is trying to do what it can to make things better," Passineau said.

The beat juice and similar solutions used by highway departments have sugars that prevents them from freezing. The solution creates a film on the road that causes the snow to freeze as slush rather than as ice, Graveen said, which creates safer driving conditions while allowing the counties to use less salt or no salt.

Since 2012, all new Portage County trucks have been outfitted with a pre-wetting system to allow liquid deicing agents to be applied immediately before spreading salt and sand on the pavement, said county Highway Commissioner Nathan Check. The Portage County fleet is equipped for applying anti-icing to roads prior to storms.

Portage County also uses underbody plows, which are more effective in removing packed snow and ice than front-mounted plows, Check said. By keeping the roads clean of extra ice and packed snow through more efficient plowing, the county uses less salt. All newer Portage County trucks have ground speed controllers, which control the amount of salt or sand used based on the speed of the truck, an efficiency that also reduces salt use.

Portage County used 64,142 tons of salt for state and county highways during the past five years.

Every year, there is a little improvement in technology that allows for better mixing and applications of anti-icing compounds to roads, Graveen said. Highway workers understand the effect on the environment when a lot of road salt gets into the groundwater, he said.

"Anything to make public travel safer and environmentally friendly are all good things," Graveen said.