Deicing impacts on water quality

If Punxsutawney Phil’s prediction is right, we may have some more snowstorms ahead of us this winter. While many of us have been spending less time on the roads this year because of the pandemic, it is still important to assess the use of deicing materials used to make the roads and sidewalks safe this time of year. While counties and cities are using their sand and salt trucks ahead of winter storms, residents have likely stocked up on deicing materials for their home driveway and sidewalks. You may be aware that deicers can be unhealthy for pets and may corrode driveways, cars and other items made of metal, but have you considered their impact to the environment, including your drinking water? While these deicers are effective, the improvement in vehicle and pedestrian safety may come at the expense of water quality if the materials are used improperly.

In line with Joint Base Myer-Henderson Hall’s commitment to protect the environment, the public and the installation’s resident animals, the Directorate of Public Works staff has been trained in the proper application of deicing materials and uses pet-friendly deicers. It is, however, important for the public to be aware of the potential impacts of deicers and how to minimize the risks.

What are common deicers and how do they work?

The most common materials used for deicing home driveways and walkways include abrasives such as sand or cat litter and commercial products that contain chemicals such as sodium chloride, calcium chloride, magnesium chloride, calcium magnesium acetate, potassium acetate and salt and other chemical deicers work by lowering the freezing point of water. As the minerals dissolve, they form a liquid layer in the ice that makes the snow and ice easier to remove. Abrasives, on the other hand, only help to break up the ice and provide traction. Unfortunately, while these materials improve our safety on roads and sidewalks, they can negatively impact water quality if they are carried off the surfaces on which they were originally applied and into storm drains and streams.

What are the potential impacts from using deicers?

When deicing materials used to melt snow and ice are washed off the road and sidewalks by rain or melting snow, the resulting runoff, called stormwater, is polluted with chemicals, minerals and sediments from the deicers. This polluted stormwater can then flow to vegetation alongside roads, streams and ponds or stormwater inlets, which carry the water to local water bodies. Deicer chemicals can also percolate through the soil to groundwater and contaminate well water in areas that use wells for drinking water supply.

According to the National Cooperative Highway Research Program, sodium chloride, calcium chloride and magnesium chloride deicers can impact water quality and aquatic life by adding too much chloride and metals. Many metals are toxic to aquatic life, even in low concentrations. Chloride deicers also often contain phosphates, which can cause algae to grow too quickly, smothering other aquatic organisms. Acetates tend to have a high impact on water quality by adding organic content, which uses up some of the oxygen needed by aquatic organisms. The abrasive deicers impact water quality by adding sediments and increasing the cloudiness in bodies of water. The sediments from abrasives can clog small spaces and smother underwater habitats that are important to aquatic life.

In addition to aquatic life, deicing materials can negatively impact pets by causing illnesses through ingestion and by irritating their skin and paw pads. Check the label of the deicing products and select “pet friendly” deicers to minimize the risk of your pets getting sick.

How can we prevent and reduce these impacts?

Many people are under the impression that more is better when it comes to applying deicers, but we need to consider these environmental impacts. Fortunately, there are several ways to reduce or prevent these impacts:  

·       Follow the directions on the packaging of the deicer and use the minimum amount possible. Deicers are meant to break the bond between the ice and the pavement or concrete to make it easier to remove, not to melt it all.

·       Use a small amount of a deicer or anti-icer (meant for pretreatment) on roads or sidewalks before or shortly after the start of a snowfall, preventing ice from bonding to the ground in the first place. This method can help reduce the total amount of deicing material applied. However, it is important to be conservative with how much pretreatment material is applied and when it is applied; avoid applying large amounts of pretreatment chemicals for just a few flurries.

·       Do some research and use the appropriate deicer. Certain deicers work better at different temperatures and in different locations. Choosing the right one can decrease the amount of deicer needed.

·       Pick up a snow shovel. Keeping up with shoveling the snow off driveways and sidewalks will help to prevent snow and ice from bonding to the pavement or concrete in the first place.

·       Store deicers in a covered area and in proper containers to avoid the material from being unintentionally spread to the environment by rain or wind.

Employing these methods can help to balance the need for improving safety during dangerous weather conditions with the need to protect our environment and drinking water quality.

To report conditions that could cause storm water pollution or to get more involved with stormwater activities on base, contact the JBM-HH Environmental Management Division by calling (703) 696-1222 or by emailing usarmy.jbmhh.asa.mbx.fort-myer-fort-mcnair-stormwater-program@mail.mil.

 

By Jen Tolbert, Environmental Management Division

JBM-HH Directorate of Public Works