Safe roads and clean water: A balancing act

Kathleen Schaefer
Instructor, Circuit Training and Assistance Program (CTAP)
Minnesota Department of Transportation
St. Paul, Minnesota

When I first began working as a highway maintenance worker, my convictions as a backyard environmentalist were at odds with my need for a good, steady job. The diesel smoke and the galvanized steel gave me concern. But what nearly sent me over the edge were the tons of salt I saw pouring from the trucks onto the roads—salt that would eventually end up in our "sky-blue waters" here in Minnesota. I questioned whether I really wanted the job, since I realized this was not going to be one of those positions where you just go out, do the work, and then go home, without ever having to think about potential impacts.

My job was to maintain safe roads, and I recognized the importance of the task as my parents, my kids and my friends drive the roads I was hired to keep safe and passable. I couldn't allow my roads to become snow covered and compacted. That wasn't an option. Nor, however, did I want to apply large amounts of salt to our environment. I felt as though I had to choose between two equally disagreeable alternatives. As another maintenance worker once said to me, "What do you want, dead people or dead fish?" "Neither," I said. I hoped there was an alternative.

Luckily there was. Within a couple years after I started in 1997, our truck station began, on a very small scale, using magnesium chloride liquid for anti-icing some of our more difficult bridges. The following year a 10,000-gallon tank was installed at the truck station and drivers could choose to pre-wet their load of salt with mag before going out on the road. The early system, well... it had some flaws. Imagine this: It's January, we've gotten about six inches of snow and now it's letting up, which means the temperature is plummeting and we have a relatively short window of time to get the roads clear before we get compaction and a tight bond. The A-shift is on, it's 2:30 in the morning, and as trucks are being loaded with salt, some pull out of the yard and others drive over to the tank of mag along the north side of the shed. Drivers climb out of their trucks, up onto a platform about 15 feet high. The north wind is picking up. The driver takes hold of the three-inch diameter hose, hits the switch and turns the lever to start the flow of liquid onto the load. When the pump kicks in the mag gushes out, some of it spraying back onto the driver. This was not the most efficient method of pre-wetting the salt.

We hadn't received much training on application rates, just some information that mag was relatively safe to handle. We were told that the department was trying some new things to reduce our salt usage and that the mag would make the salt stick to the road better and could melt ice at lower temperatures than salt, thereby reducing our overall salt usage. Things were starting to look up.

Though it was mighty uncomfortable to climb up on the platform in that icy wind and spray down the load, more and more drivers began using the liquid as they saw that roads where the mag was used were clear faster and with fewer passes. A little effort up front made the rest of the job easier. Benefits were becoming apparent, even if it was only that it made the job easier. A reduction in salt was imminent.

Over the years we've come a long way. Now all our new trucks are outfitted with saddle tanks for onboard pre-wetting and calibrated so the proper amount of material is applied. Newer and better materials, application methods and equipment are being researched and tested all the time to help reduce salt usage.

Plow drivers attend training workshops to learn about new materials and equipment. They also learn of the negative impacts of salt on our lakes and rivers. They are taught that salt and other deicers have temperature limits beyond which it becomes wasteful and harmful to apply the materials. The message they receive is that they can turn down the application rate and still maintain safe roads through the use of the new technologies available to them. A balance can be achieved.

Though things are looking up, we still have a long way to go. Changing the mindset of folks who have been doing something one way for many years is always a challenge. Also, just the idea of applying a liquid to a road in Minnesota in the winter seemingly goes against all good judgment. In addition to getting people to accept liquids, we're seeing more and more cities and counties and private parking lot plow companies moving away from sand and going to straight salt. This is evident in the chloride levels in our urban streams in the St. Paul/Minneapolis area.

What I find most encouraging is that a serious dialogue has begun between the DOT, environmental groups, city and county public works, and watershed districts. The spirit of cooperation is evident between the representatives of these groups as all realize the necessity of working together to find the right balance to maintain safe roads and protect our water.

I've since left the position as a highway maintenance worker. Though I don't miss the 12-hour shifts from 1:30 a.m. to 1:30 p.m., I do miss the feeling of satisfaction I'd get when the sun would come up and traffic would start to move and suddenly my road was wet from shoulder to shoulder. I also miss the gang plowing when we'd have five to seven trucks all working together to pull the road, or the sight of the snow flying off the end of my wing (that was cool). I've moved on to a training position, a partnership between MnDOT and the University of Minnesota LTAP, where I can help others understand how to achieve a balance between maintaining safe roads while reducing the impact on our environment.

Kathleen Schaefer can be reached at (651) 282-2160 or at kathleen.schaefer@dot.state.mn.us.

Salt Brine: Breaking Snow and Ice Bonds on Your Pavement covers application rates for liquid treatments, what kind of equipment is needed, when to use salt brine and when not to, cost comparisons between salt brine and other chemical applications, and the challenges involved in setting up a liquid treatment program. Salt Management Guide addresses three key issues relating to road salting: the effects of transportation on the economy and quality of life in Canada, the environmental impact of road salting practices, and road salt management. Winter Roads: Effective Use of Chemicals and Abrasives for Winter Roads Maintenance discusses the basics of chemical and abrasive usage for snow and ice control. All are CD-ROMS and can be ordered online at www.apwa.net/bookstore or call the Member Services Hotline at (800) 848-APWA, ext. 3560.