Best Management Practices for homeowners – Rock salt sold in hardware stores is usually the same substance that municipalities spread on roads. Just like on the roads the salt spread at home remains in your yard affecting your well water, animals, soil, and gardens.
You can also reduce the salt you need by creating a brine solution by mixing a little salt and warm water and applying it to your driveway and walkways.
Try to apply salt only on patches that you know are icy. Consider buying cleats that you can put over your shoes or boots to avoid slips and falls.
Explore alternative de-icing products made from organic minerals such as Eco Traction.
If you need to use salt, remember these five tips developed by the University of Vermont Seagrant Lake Champlain:
- Shovel first – You should always shovel any snow or ice away before putting salt onto a hard surface. It takes less salt to do the same job and works more quickly.
- Maintain 3-inch spacing between grains of salt – A rule of thumb is that grains of salt should be about 3 inches apart. This graphic from the Lake Superior Regional Stormwater Protection Team helps to visualize this. If you prefer to measure salt, a general guideline is to use no more than 1 to 1.5 cups per every two parking lot spaces or 10 sidewalk squares.
- Measure pavement temperature – Since rock salt works only down to pavement temperatures of 16F (-9C), you can use an infrared thermometer to determine pavement temperature.
- Sweep up extra salt to reuse – If you accidentally used too much salt during one storm and see piles of salt on the pavement following the storm, sweep up the extra salt and reuse it during a future storm. If you leave it on the pavement, it will runoff to nearby vegetation, to a local storm drain, or into a local water body.
- Ask contractors to limit salt use – If you hire contractors to maintain your driveway and/or sidewalk, speak with them about how you would like to have your property managed. Some private contractors may have the ability to use a 23% salt-water mixture ahead of a storm (called anti-icing) to prevent a bond from forming between the ice and snow and the pavement. Anti-icing can reduce salt use (as compared to using dry salt) by as much as 45%. Even if the company who maintains your property cannot anti-ice, being proactive to communicate with them about your interest in limiting salt use will allow them to feel comfortable salting only where they have a concern or using an alternative to sodium chloride during very cold weather.
Best Management Practices for Road Salt Applicators
Many departments of transportation have begun using a 23% salt brine solution to pre-treat roads before the onset of storms. Estimates suggest that road pre-treatment with brine can yield a 75% savings in total salt applied
Pre-wetting salt before roadway application can reduce salt infiltration to aquifers by 5%. Bounce and scatter of dry rock salt is reduced when the salt is pre-wetted. Pre-wetting salt allows it to stick better to the road, which minimizes spray and kick-up of salt grains.
Calibration of equipment
Calibration allows you to measure the exact amount of material you apply, facilitating more accurate and efficient de-icing, with less total salt used. You don’t need a regulator to calibrate your equipment.
Calibration procedures – which are readily available in online manuals – should be a standard component of trainings for salt truck operators.
Variable application rates for salt distribution systems
Automated spreader controls allow salt truck operators to program salt application rates so that the amount of salt being applied changes with ground speed, which reduces bounce and scatter. These programs can also account for curves and hills, which require more salt than flat or straight roads. Vehicle location sensors can target salt distribution to a precise location along a route. This kind of information can allow for fine adjustments and keep track of total salt distribution for salt monitoring purposes.
Proper salt storage
To minimize salt loss and pollution, salt piles should be contained. Municipalities and privately- owned facilities can protect salt investments and the environment by adopting storage best practices. These include building salt storage sites on impervious surfaces, implementing secondary containment measures, completely enclosing salt piles, and regularly inspecting structures for breaks or tears.
Unintended spills and releases of road salt from vehicles are inevitable. Allowing time to clean up spills will reduce unwanted release of salt to the environment. Also, collection systems are now available to promote the recycling of vehicle wash water, which can be used to produce brine for anti-icing applications.
Road condition information systems
High quality data on road and weather conditions should be shared between transportation officials and weather forecast providers to facilitate targeted, coordinated road salt application. In addition, smart phone apps, cell phone text alerts, and web-based platforms are increasingly allowing travelers to make informed decisions about road conditions before travelling.
Modern plows are designed to reduce the amount of road salt needed to maintain ice-free roads. For example:
- Live edge blades have articulated segments that conform to uneven road surfaces.
- Flexible plow blades conform to uneven surfaces thus reducing the overall amount of salt needed. They also extend the life of a plow
Pavement temperature sensors
Pavement temperature determines whether frozen precipitation will stick and how much salt is needed to maintain safe winter roads. They can help guide salt application by road crews and inform the public about the safety of road conditions.
Adjusting levels of service
Several states adjust levels of service to conditions. For example, the Vermont Transportation Department seeks to provide ‘safe winter roads at safe speeds’ – not necessarily bare roads. New Hampshire, Ohio, Colorado, and other states define varying levels of service based on traffic volume.
Surveys can help gauge the public’s expectations and comfort level with varying levels of service. For example, after surveying the public, the Minnesota Department of Transportation was able to adjust its practice of maintaining bare pavement during a storm to maintaining bare lanes.
Expanding the practice of adjusting levels of service to match expectations and traffic volume has the potential to drastically reduce the overall amount of salt released into the environment.
In the state of New Hampshire, parking lots and other surfaces maintained by commercial salt applicators are the largest source of chlorides.
Identify no / low salt areas
Some road service agencies have identified areas of low or no salt near sensitive freshwater bodies such as reservoirs, lakes, rivers, streams, and well fields that feed public water supplies. Educating travelers in these areas is critical.
Commercial Salt Applicators certified by NHDES Green SnowPro under RSA 489-C, and property owners or managers who hire them, are granted limited liability protection against damages arising from snow and ice conditions under RSA 508:22. To learn more about becoming a Green SnowPro certified salt applicator and learn more about responsible salt application visit: https://www.des.nh.gov/land/roads/road-salt-reduction/green-snowpro-certification
For a list of Green SnowPro certified contractors working in New Hampshire click HERE.