Snow removal on campus at the University of Wisconsin-Whitewater is no easy task. It requires a large staff, a variety of jobs and equipment, and literally tons of salt. Salt use is particularly significant because it has the potential to suck the life out of our precious waterways. Any kind of salt is a chloride, which is harmful to fish and plant life at high concentrations. This affects local waterways when salt washes into them through melting snow into storm drains. It also can affect plant life and soils where salt is distributed onto land areas in high concentrations. This chloride can also percolate into the groundwater supply and pollute our drinking water. Chloride pollution can even affect pets and wildlife that encounter de-icing materials or try to ingest them. This issue is taken very seriously on campus because of these environmental impacts as well as the economic cost of salt use during times of declining budgets and its corrosive impact on infrastructure and vehicles. To develop effective strategies to deal with snow and ice, much time and effort is spent preparing and planning for snow removal before the work even starts on removing the snow itself.
The main goal of the University of Wisconsin-Whitewater Facilities Planning and Management (FP&M) Grounds Crew snow and ice control operation is to maintain adequate traction for pedestrians and vehicles properly equipped for winter conditions. Snow and ice storm control and removal efforts always attempt to make the campus accessible by 7:00 am. Accessible typically means “one pass” completed by motorized snow and ice removal equipment or hand shoveling in the following areas: roadways and service drives, walks, commuter lots, residence hall lots, stairs in academic zones. and curb cuts for wheelchair accessibility throughout campus. When a forecast predicts a snow or ice event, it is the Grounds Crew’s intent to spread salt brine solution over heavily used traffic areas on roads, walks, and parking lot lanes within 24 hours of the predicted precipitation event. Brine solution is used as an effective as a pre-treatment solution and granular salt is used on sidewalks, roads and parking lots to deal with ice build-up after plowing for storm events.
The magnitude of salt used on campus during a typical winter would probably surprise most people. Estimated salt used in brine or direct granular applications on campus roadways and sidewalks in the winter of 17-18’ (up to February 26th, 2018) was 168,000 pounds and can be spread at rates up to 38 pounds per minute. This total does not include salt used on stairs, entrances, or other areas close to buildings where hand-removal is completed by building staff. More data, dating back to 2005 indicates that anywhere from 66.31 – 386.94 tons of salt was used on campus in recent winter seasons. To spread rock salt for ice build-up, the FP&M Grounds Crew snow and ice control operation uses five ToolCat machines with .5 cubic yard each to spread at least 2.5 tons of rock salt for each storm event. Additionally, sand is also used on campus and is beneficial because it is not as damaging to the environment as salt. Sand is useful to increase traction, but does not have the same ice-melting properties as salt. According to the same data for roadways and sidewalks, anywhere from 32.94 – 762.18 tons of sand were used on campus in recent winter seasons.
At UW-Whitewater, the FP&M Grounds Crew makes the salt brine solution in a large two-part mixing tank for pre-treatment applications prior to predicted storm events. According to salt brine usage statistics for 2017-18, the crew uses four main setups for dispensing salt brine one roadways, parking lot lanes, and sidewalks. Setup 1 is a flat-bed truck with a gravity-fed boom connected to a 225-gallon tank to cover all roads and parking lot lanes south of Starin Road with 450 gallons of brine used per storm. Setup 2 is a dump truck with a gravity-fed boom connected to a 525-gallon tank to cover all roads and parking lot lanes north of Starin Road with 625 gallons of brine used per storm. Setup 3 is a ToolCat with a pressurized boom connected to a 225-gallon tank to cover all sidewalks south of Starin Road with 400 gallons of brine used per storm. Setup 4 is a ToolCat with a pressurized boom connected to a 300-gallon tank to cover all sidewalks north of Starin Road with 300 gallons of brine used per storm. Added together, the pretreatment uses 1,775 gallons of brine.
The switch from rock salt to brine in pre-treatment applications has economic implications. Previously, rock salt was used as a pre-treatment and 2.5 tons of salt was needed to cover all roads, parking lot lanes, and sidewalks. On the other hand, to formulate the 1,775 gallons of brine about 1.5 tons of salt is needed. Based on current prices of $64/ton, this saves the university the cost of one ton per storm event. If there is a storm event occurring bi-weekly from December-February alone, this saves the campus nearly $400 in salt costs. There is some additional labor involved with formulating the brine, but often the pre-treatment can help save labor costs in other areas. Brine solutions can help avoid ice build-up and make snow removal operations more efficient.
It is clear that the future of winter maintenance involves proactive liquid-only strategies instead of granular salt. Liquid solutions can melt snow and ice faster than granular salt due to its more even distribution patterns and is more effective at lower temperatures. Liquid solutions can be extremely cost effective since it takes less product and reduce overall application time if done correctly. It also helps crews stay on target by eliminating bounce, scatter, and tracking problems associated with granular products. Finally and most importantly, liquids lessen environmental impact. The lower salt concentrations of liquid deicers are less damaging to our lakes, rivers, and groundwater. They also have less likelihood of runoff into our local storm drains, which lead directly to Whitewater Creek on our campus. The particle size is also not as impactful to pets and wildlife.
Besides the economic and practical benefits of liquids and other best practices for granular salt applications, there is one simple reason why minimizing salt use matters: salt usage drastically impacts our environment, especially our waterways. Just one teaspoon of salt pollutes five gallons of water forever and just one pound of salt contains about 80 teaspoons. This is why the work done by the FP&M Grounds Crew to minimize salt usage in the winter is so important and crew leaders are optimistic about future snow removal tactics using even less salt. They have upgraded calibration on their ToolCat machines to minimize unnecessary salt usage for sidewalks of various widths by controlling “bounce and scatter,” which also reduces the impact on the vegetation along the edge of sidewalks. Additionally, Bobcat does make gear that they can use to reduce amounts of salt dumping. Granular salt can also be wetted as it comes off the truck to help it stick to pavement areas better. More advanced methods include switching to GPS electronic controls that adjusts distribution rates of liquid or granular salt to vehicle speed and maintaining pressurized brine pumping systems on all of the equipment will help more even distribution of brine solution and avoid the challenges introduced by manual, gravity-fed systems.
Municipal crews like UW-Whitewater FP&M Grounds Crew have been adopting best practices to meet snow and ice removal needs and increasing expectations by residents. While these removal techniques have yielded drastic improvements in the safety and accessibility of roads and sidewalks in winter, the overall expectation has also risen accordingly. Increasing expectations and improper preparation for traveling in winter weather often forces crews to increase their salt usage to meet these demands. Even with these best practices, salt use can be further reduced by homeowners understanding the proper application rate for their own hand-removal efforts and by preparing for traversing the winter landscape with adequate footwear or vehicle tires. Salt is a useful tool to create a safe winter landscape for travel, but should be used sparingly and with its harmful impacts on the environment and our local watershed in mind.