Controlling dust a costly proposition

Road chemical desired by residents, but townships can’t afford the price tag

By Susan Larson | The Daily Journal

Published 01:25 p.m., March 15, 2007

At least one township is weighing the cost of laying a chemical on gravel roads to control dust against requests from residents.

At approximately $2,000 a mile, application of magnesium chloride is more than many townships can afford to spend to keep its rural neighbors dust-free.

The chemical, a salt-byproduct, helps keep dust kicked up from traffic at a minimum by drawing moisture from the air and keeping the road surface moist, according to Otter Tail County Highway Engineer Rick West. Application of the chemical is usually paid for by the township and residents along the road.

“We started two years ago putting it on two high-traffic roads,” Otto Township Clerk Russ Kadow said. “Then we put it on a dead end road to Rush Lake” at the request of the residents who lived there. “We want to put it on more roads we have to rebuild because it will take less to maintain them in the long run. But when you’ve got a road where it’s needed but there’s only two residents there, it won’t work. We’re trying to come up with a way we can do it that will be fair to everyone.”

Newton Township has discontinued its use altogether.

“We used it for several years,” Christopher Roberts, Newton Township chairman, said. “We haven’t for the last two or three years because it’s so expensive. It costs about $1 a linear foot.

The county uses it on its roads as a de-icer in the winter. It costs about $1.01 per gallon, West said. The county budgets $40,000 a year for it, so approximately 40,000 gallons are used each year, “depending on what kind of winter we have.”

“It’s good stuff, but we don’t have the funding for it,” Roberts

said. “It holds the roads together, but it’s hard to tell if it’s really saving us any money in the long run. For now, we do nothing. We just live with (the dust) — that’s how it is. But we still maintain our roads pretty well with gravel. As long as a road is graveled, it will be OK.”

Environmental concerns and expense have curtailed the use of magnesium chloride in Rush Lake Township.

“It’s become expensive the past five years,” Andy Klinnert, township chairman, said. “And even though it’s a naturally occurring compound and it’s a safe product, obviously it contains a certain amount of heavy metal (magnesium). We used to use it more, but some residents were opposed to it, so that’s why we’ve limited its use. We do about four miles of road a year at residents’ request (who share costs with township 50/50). It’s up to the people.”

Only the green in the wallet and not the green of the environment concerns Roberts.

“It’s salt, so it just rusts the vehicles,” he said.

Magnesium chloride is extracted from saltwater solutions, such as sea water, according to the Center for Transportation Studies, University of Minnesota. Besides dust control, it can also be used for color retention and firming agent for canned vegetables; a coagulant of soy milk with magnesium sulfate (epsom salts) to make tofu; in infant formula; as a dressing agent in cotton fabrics; in sugar beet processing; and as a disinfectant.

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