Salt Impacts & Our Environment
We rely on salt to keep our roads, walkways, and driveways safe and, in some instances, to treat our drinking water, but using more salt than is needed comes with a price both literally to our wallets and metaphorically to our environment. What can you do to reduce the amount of salt added to the environment?
TIPS FOR RESIDENTS | TIPS FOR MUNICIPALITIES & PRIVATE APPLICATORS
The key to minimize salt pollution is to use less salt in all applications
TIPS FOR RESIDENTS
Reducing Salt Applications
Be mindful of where you apply salt, what you apply, how you apply, and when you apply!
Where
When applying salt to walkways and driveways, think about how close you are to drinking water wells, planted gardens, trees, bodies of water like lakes or streams, and storm drains. Storm drainage systems likely discharge to water bodies and can travel all the way down to Long Island Sound. While it may seem harmless to discharge salty water to Long Island Sound, any salt water will first have to travel through freshwater systems down to Long Island Sound. The salty water can cause harm to freshwater animals and plants along the way.
What
|
Type of Salt/Material |
Ideal Conditions for Use |
|
Sodium chloride (NaCl) |
Effective down to 15° F. The most common de-icing salt commercially available, also known as “rock salt”. |
|
Calcium chloride (CaCl2) |
Effective down to -20° F (not very common in CT). Contains twice the chloride as sodium chloride, so it should be used sparingly. |
|
Magnesium chloride (MgCl2) |
Effective down to -10° F. Commonly used in “pet-safe” salts. Often mixed with NaCl in most commercial grade de-icing salts. Contains twice the chloride as sodium chloride, so there is no need to over apply. |
|
Calcium magnesium acetate |
Salt-free product effective down to 20° F. Safer for vegetation and concrete surfaces BUT can still impact freshwater organisms. Should be applied conscientiously. |
|
Sand |
Provides traction when dry. Traction effect lost once wet or displaced by vehicles. Does NOT melt snow or ice. |
How
No salt method – To minimize salt use, light snow can be cleared from surfaces with a hard-bristled brush or broom. Deeper snow can be cleared with a shovel or a snowblower. Ensure that melting snow and ice doesn’t pool in high traffic areas to leave puddles that may later refreeze. Ice breakers/choppers can be used to break up icy patches.
Salt method – “More isn’t always better,” particularly when it comes to salt. Applying thick layers of salt can actually attract water to the surface and make ice patches. When it comes to salt application “a little goes a long way.” If you need to use salt to manage snow/ice, there are two common salt application practices: scattering rock salt or spraying a diluted brine solution.
When
There are two “schools of thought” for managing snow and ice, anti-icing or de-icing:
|
Anti-Icing |
De-Icing |
|
This method requires applying brine and/or rock salt prior to a winter weather event. The purpose is to create a layer of salt on the pavement to prevent ice and snow from bonding to surface. |
This method requires applying rock salt after snow has been removed from a surface during, or after, a winter weather event. The purpose is to allow the salt to react with the solid ice/snow to form liquid water which creates a chain reaction to melt the solid ice/snow.
|
|
Considered “preventative” or “preemptive” |
Considered “reactionary” |
|
Brine can be applied 24-48 hours ahead of a winter weather event. Don’t apply if it is going to rain. |
Brine is not effective for de-icing applications because the solution can freeze when temperatures drop during a winter weather event. |
|
If using rock salt before a winter weather event, make sure to walk/drive on the salt to crush the salt crystals so that the salt will be ready to react with the snow/ice on contact. More surface area for the salt crystals is better. |
Rock salt crystals need time to react with snow/ice when applied during a winter weather event. |
|
Research has shown, on average, the anti-icing method helps to decrease the total amount of salt needed to be used during winter weather events. |
Smart Salt Storage
Store salt in airtight containers. Salt will absorb moisture from the air and become a solid mass over time making it difficult to work with.
Store salt inside away from the elements. You don’t want your salt to be exposed to rain or snow which can cause it to dissolve uncontrollably into the environment. Improper salt storage can impact groundwater and nearby water supply wells.
Water Treatment Management
If you own a well, you are your own water system manager, so you are responsible for deciding what water treatment systems you want to use based on your water quality needs.
Hard water and Ion exchange systems
Much of Connecticut’s bedrock and soil contains minerals such as calcium and magnesium which can make water “hard,” so hard water is relatively common throughout the state. Hard water can cause lime scale build-up on household plumbing and fixtures causing clogging and/or affecting water pressure. More information on hard water can be found on the DPH Private Well Program page.
One of the most effective and affordable treatment options for hard water (and other minerals/contaminants) is ion exchange. Ion exchange treatment systems are also known as “water softeners”. These systems use salt (either sodium chloride or potassium chloride) coated resin beads to swap out magnesium, calcium, and other minerals or contaminants out of the water and replace them with sodium or potassium.
Ion exchange systems periodically “backwash” with a concentrated salt-brine solution to recharge the resin beads. After the recharge process, the salt-brine backwash is discharged to a dedicated location outside of the home. This backwash process is another source of salt to the environment.
Salt-based water treatment management
If your goal is to minimize your salt footprint, you should discuss options with a licensed water treatment contractor. Water treatment contractors can help you determine if salt-based technology such as ion exchange is necessary based on the quality of your well water or if there are alternative salt-free water treatment options. They may also help you identify ways to improve the efficiency of your existing system or how to upgrade to a more efficient system that uses or produces less salt.
Sodium chloride vs. potassium chloride
Most often, residents use sodium chloride as the regenerant for their water softeners. However, some residents choose to use potassium chloride. Both sodium chloride (NaCl) and potassium chloride (KCl) are “salts”. When these materials dissolve in water they break up into sodium (Na) ions, or potassium (K) ions, and chloride (Cl) ions that stay in the water. While using potassium chlorides may decrease the amount of sodium in your treated drinking water, the backwash for the treatment system will be flushed with the potassium salt and still discharge a brine solution outside of your home.
Higher efficiency salt-based systems
Often salt-based technology can be the best tool for the job. However, there are different types of ion exchange systems commercially available; these are “timer-based” and “on-demand.” Newer, more efficient, ion exchange system technology includes the use of an “on-demand” backwash mechanism. The on-demand system sets the backwash to occur after a certain volume of water is used, rather than setting the backwash to occur at the same time every week. This minimizes the amount of backwashing that occurs when less water is being used, like when you are away on vacation.
Other northern states, such as Wisconsin and Minnesota have demonstrated consistent maintenance or upgrading of ion exchange systems can significantly reduce salt discharges to the environment and save homeowners money.
Alternative water treatment options
Fortunately, there are alternatives to salt-based ion exchange for addressing different types of water quality issues. In some areas of Connecticut, well water may have high concentrations of iron, manganese, arsenic, uranium, or other minerals. Each of these minerals can require different types, or combinations, of treatment. Talk to your water treatment contractor, local health department, or the DPH Private Well Program about possible alternatives to salt-based technologies to achieve your water quality goals.
Other Potential “At-Home” Sources of Salt
“Homeopathic” or “Natural” Weed Sprays
Made with household products such as table salt, kosher salt, and baking soda there is a common misconception that, because this solution is made with household products, it is “safe” for the environment. Unfortunately, this “homeopathic” weed spray does not discriminate between weeds and plants that you want to protect. Rather this spray adds unnatural sources of salt to the soil which can change the soil chemistry and structure which can impact plant health. Ultimately, this salt will wash away into the groundwater or into surface waters.
Lawn Fertilizers
It’s always best to first test your yard soil to see what nutrients your soil may be missing in your garden beds and lawn. Many lawn fertilizers contain some chloride-based salts as sources of plant nutrients, including salts that contain potassium, calcium, and magnesium, so using these fertilizers can introduce more salts to the environment than is needed. When using fertilizers, make sure to always follow the application instructions on the packaging and be mindful of where you use fertilizers, particularly if you have a water supply well on your property. Read more about impacts of excess salt on soil and plants here and best management practices around wells on the DPH Private Well Program page.
Car Washing
Many Connecticut residents prefer to wash their cars at home, but have you ever thought of what you’re washing off your car and putting into the ground? Often, we do not consider the possible environmental consequences of washing our cars. For example, by the end of the winter season, every car in Connecticut has likely been coated in some amount of salt. It is best to wash these salts off your car to protect and extend the life of your car. However, it’s important to consider where you wash your car. When you wash your car at home all the salt, and any other pollutants, soak into the ground and continue to cycle.
It’s recommended that residents use a water-only rinse at a commercial car wash to remove salt from your car to help minimize your salt footprint. Commercial car washes have wastewater collection systems designed to capture the dirty water. The captured water is either sent to a local sewer system for treatment or it is pumped out by a separate company and hauled off-site.
To read more information about how to wash your car while protecting the environment, go to Charitable Car Wash Guidance (ct.gov).
Reducing Your Salt Usage Can Save You Money!
It may not seem likely, but reducing your salt footprint can save money long-term from simply reducing how much salt you buy to reducing the potential damages to your property.
A 50 lb bag of deicing salt (sometimes called “ice melt”) can range from $10 to $25. Some bags recommend using 1 cup of salt per 20 sq ft of space! At that rate one 50 lb bag of salt would only treat up 1,600 sq. ft. Depending on the weather that could mean buying multiple bags of salt in a one season. But, as shown above, one 12 oz coffee cup is enough to treat 500 sq ft. If using reduced salt practices, you could make a 50 lb bag last much longer and save you money, time, and effort.
Over-applying salt can also cause damage to your home. Tracking in excess salt on your shoes can damage any metal door plates and make a mess inside your home. Any extra salt left on your walkway or driveway can be washed away into the groundwater and cause damage to gardens or trees on your property or even impact your drinking water if you have a private well.
With the costs of homeownership increasing, it is even more incentive to minimize damages to your property. By reducing salt use on your property you can minimize the chances of expensive repairs, replacing appliances, or even impacting your own drinking water.
TIPS FOR MUNICIPALITIES & PRIVATE APPLICATORS
Salt Application Best Management Practices
UConn’s CT Training and Technical Assistance Center (T2 Center) has provided CT Green Snow Pro training to support best practices and sustainable winter operations to state and municipal applicators since 2018. This training program was expanded in 2022 (Public Act No. 22-118) with the development of a class to meet the needs of private commercial applicators. There are two classes available. One class for the applicators who maintain roads (CT Green Snow Pro for Roadways) and one class for applicators who maintain parking lots and sidewalks (CT Green Snow Pro for Parking Lots and Sidewalks). While these classes are voluntary, it is highly recommended that all winter maintenance professionals enroll in the training. Using less salt not only benefits the environment but may also positively reduce salt budgets and expenditures, operational efficiency, and prolong the use of expensive equipment.
Best Management Practices for Salt Storage
Not only does salt melt ice and snow, but it also absorbs moisture from the air. When rock salt used for deicing is stored outside, it will pull water out of the air and over time turn into a solid brick. That’s why it is important to maintain salt piles under weathertight and waterproof structures.
As far back as the 1980s, DEEP (then CT DEP) investigated multiple cases of salt impacts to drinking water that originated back to improper salt storage in locations that allowed the salt to dissolve in the weather and leak into soil and groundwater. While not as frequent, improper salt storage has caused impacts to many wells across the state within the past decade. Any uncontrolled release of salt to the environment can cause unintended impacts. That is why proper storage of salt is always important.
To minimize any salt unintentionally getting into the environment, salt piles should be stored on an impervious (impenetrable) surface, such as asphalt, under a roof, and should have physical barriers, such as absorbent booms or haybales, around the salt to absorb any salt that may dissolve over time. Salt that is spilled while loading equipment (including trucks and other spreaders) should be swept up immediately and returned to the pile.
Guidance for proper salt storage can be found in DEEP’s “Connecticut’s Aquifer Protection Area Program: Municipal Manual” and in Technical Guidance jointly published by DEEP’s Stormwater and Aquifer Protection Programs.
Best Management Practices for Disposal of Street Sweepings
The Connecticut Department of Transportation (CT DOT) and many municipalities have shifted away from using sand/salt mixtures to using only salt products combined with anti- and de-icing practices. However, there are still CT municipalities who use sand/salt mixes as part of their winter maintenance practices. Any sand applied to roadways must be properly swept up from road surfaces and cleaned from catch basins every spring. While sand provides temporary traction in winter weather, it also picks up potentially harmful materials like heavy metals and petroleum chemicals from motor vehicles. These street sweepings can carry these potentially harmful materials through stormwater systems into waterways and they can clog catch basins and stormwater systems which can increase the risk of localized flooding.
More information about how to properly manage and dispose of street sweepings and catch basin materials can be found in DEEP’s Guideline for Municipal Management Practices for Street Sweepings & Catch Basin Cleanings.
Best Management Practices for Snow Removal
Often, we don’t think of where we pile our snow because it is going to melt and “go away.” However, whenever snow is removed, moved, or placed, it is important to consider if the snow may contain deicing salts because the final placement of that snow could become a hotspot for salt as the snow melts. DEEP has investigated cases where snow was piled up in locations that caused drinking water to be impacted. As a result, DEEP published a webpage that provides guidance for Best Management of Disposal of Snow. These guidelines were published for the benefit of municipalities and other applicators, but many of the practices included are useful for residents too!
Evaluating and Implementing Remedial Options in Cases of Salt Impacts to the Environment
DEEP staff can provide knowledge of salt geochemistry, hydrogeology, and geology to assist municipalities in evaluating source(s) of salt related impacts. While DEEP can provide technical assistance, DPH can provide health-based assistance when evaluating the source(s) of salt and potential remedial options.
Salt Tolerant Plants Ideal of Urban Landscaping
It is important to consider what type of conditions plants will endure when incorporated into urban landscaping such as along roadways and within sidewalks. Salt applications to walkways and roadways can impact both the soil around the plant and the plant itself leading to poor health or death which can affect “curb appeal.” Salt-tolerant plants may have a better survival rate along roadways, or in walkways. Planting more salt-tolerant plants may be a better overall investment for municipalities when considering urban planting. You can find more information on how salt impacts both soil and plants, along with a list of salt-sensitive and salt-tolerant plants .
Reducing Your Salt Usage Can Save You Money
In July 2015, the Connecticut Academy of Science and Engineering (CASE) published a report titled “Winter Highway Maintenance Operations: Connecticut.” This report reviews the effects of deicing salts and the implementation of anti-icing application techniques on vehicles, roadway infrastructure, the environment, and the economic costs of those effects. The authors of the CASE study compared the number injury-causing car accidents that occurred in the years prior to when CT DOT started using anti-icing techniques. They found the number of injury-causing car accidents decreased by >2,400! This means the number of vehicle-related injuries on state roads decreased when less salt was applied. Reducing the number of accidents combined with reducing the amount of salt used saved the State money both in health-care costs and the cost of salt.
Dr. Michael Dietz, UCONN Center for Land Use Education and Research (CLEAR), published a study in 2020 that showed both financial savings and positive environmental impacts when salt applications were reduced at the UCONN campus. The result of the study concluded that after receiving Green Snow Pro training, campus facilities staff applied 3,479 fewer metric tons (that’s over 7 million pounds!) of salt in the 2 years after receiving the training. This amounted to $459,251 in savings.
The cost of salt only continues to rise, so reducing the amount of salt can be significant to your Town’s budget.