Deicing strategies

The snow and ice management industry is constantly changing as more data and information becomes available to the industry. In the past seven or eight years, the industry has seen two salt shortages, pricing structures becoming depressed (and rebounding), and available labor resources being squeezed by a recently energized and fast-growing economy.

Progressive snow and ice management contractors have learned and accepted that deicing is a profitable service and that providing a safe environment for vehicular and pedestrian traffic. Professional snow and ice management contractors now offer deicing services as a matter of course in their service offering. Some things have not changed though. Independent outsourced service providers tend to take better care of their equipment than hourly rate employees.

Ice control on parking lots requires some capital investment. While a truck is needed, it does not necessarily need to be a truck outfitted with a plow. In fact, there are some compelling arguments that having a truck plow and salt is not an effective use of resources. Pounding a truck into a pile of snow repeatedly can create maintenance issues that can become expensive. Trucks are designed to “haul things” and hauling and spreading salt is less taxing on rolling equipment.  At one point, this author believed that boom mounted salt spreaders affixed to backhoes would become popular. That did not catch on, and that idea has gone by the wayside.

Technically, salt still works the same way today as it did 10, 20, or 30 years ago. Salt, sitting on the paved surface, is inert unless moisture is introduced and comes in contact with the granular rock salt. Once it starts to snow, the moisture causes the salt to dissolve into solution. The resulting salt brine prevents ice and snow from bonding with the pavement surface. Since no bonding takes place, once plowing operations commence the snow or slush is easily removed. This leaves a cleaner surface than if you plow the site after the snow and ice has bonded to the pavement.

The nice thing is you can achieve this result by using only one-third the amount of product required for traditional deicing. If it does not continue to snow after completion of plowing operations, there is often no need to reapply salt to the cleared surface. If an additional application of salt is required, desired results can be achieved with considerably less material than you would have needed had you not been proactive.

Anti-icing has become more prevalent in the industry than it was 10 years ago in the private snow contracting business. It was a great process in 2011 and even more so now. As liquid products have grown in popularity, anti-icing (or pre-treating) has made quite an impact on the entire snow management industry. It is estimated that the use of liquids and anti-icing among the for-profit snow contracting business has tripled in the past 8 years. I don’t doubt that at all. Given the recent squeeze on salt supplies, the increased use of anti-icing (which requires only about a third the amount of product as deicing activities.  All things considered, the astute contractor can actually use half the normal amount of salt by having an anti-icing program in place. Most contractors who anti-ice (or pre-treat) also make a very light application of salt after the plowing has been completed.

As for what amount of product is needed to achieve desired results, the protocols have not changed. Don Walker from the University of Wisconsin, one of the leading authorities on deicing in the country, stated that 200 pounds of rock salt applied evenly on 1 acre of surface is adequate to reduce a light to medium buildup of ice to a liquid form.

Various DOT studies indicate that in a light-icing situation, 200 to 250 pounds of rock salt per acre is all that is required to reduce a light accumulation of ice to water at approximately 28 degrees. Under these conditions, the melting process will take 45 to 60 minutes to complete. A heavy accumulation of ice may require as much as 350 pounds of rock salt per acre. This may seem absurdly low, but these low application levels are attainable.

Studies performed in the early 2000’s showed us that as little as 75 pounds of rock salt will address a light icing on 1 acre of pavement. Unfortunately for contractors, the V-box, slide-in spreaders can only be calibrated down to about 300 pounds per-acre distribution. There are spreaders on the market that can go as low as 75 pounds per acre, but the cost of these units is well over $75,000. Normally, this is out of a commercial plowing contractor's price range, however with proper cost analysis it has become much easier to cost justify such an expenditure.

Educated contractors are no longer trying to convince customers they are applying one ton of salt per acre of pavement. The cost of rock salt has escalated dramatically in the past 10 years, which makes using that much product unnecessarily cost prohibitive to the customer as well as the contractor. Still, contractors often apply more salt than is necessary. Uneducated customers do not help the situation by insisting the pavement be “crunchy” under their feet, erroneously believing that “more is better.” In actuality, this has some negative consequences by doing more harm to the environment than is necessary. The next time you see a white parking lot the day after a snow storm, it is likely the contractor over applied salt to the lot – or has been told to do so by an uneducated customer.

The effective and efficient use of rock salt on parking lots can go a very long way towards providing a safe environment for vehicles and pedestrians. It can also reduce legal costs associated with slip-and-fall complaints. Ultimately, everyone benefits from a parking lot that is safe to drive or walk on. That fact has NOT changed since that September 2011 article.

The author is a full-time consultant to the snow industry and owner of John Allin Consulting.