News Release, Maryland Department of the Environment
Residents urged to stay safe in winter weather but cut back on salt when possible
BALTIMORE, MD (January 18, 2019) – As winter weather impacts the state, Maryland is working to reduce the use of road salts that can threaten public health and the environment – including the water that we drink – while keeping traffic moving safely.
The Maryland Department of the Environment (MDE) is taking steps to reduce salt in rivers, streams and groundwater to protect aquatic life and drinking water sources while roads are made safe for winter travel. MDE has been working for several years with state agencies and local jurisdictions on best practices for salt application, including use of improved weather forecasting, using the right amount of salt, targeting roads in most need of treatment, using brine to reduce overall salt usage and increasing training for employees and contracted equipment operators. The Maryland Department of Transportation State Highway Administration (MDOT SHA) employs a range of strategies to reduce its use of salt while continuing to keep roads safe – and over the past five years has reduced its overall salt usage by half.
“The Maryland Department of the Environment congratulates and thanks the State Highway Administration for leading by example when it comes to reducing the use of road salts that can threaten public health and our environment,” said Maryland Environment Secretary Ben Grumbles. “This winter, we urge all Marylanders to make smart decisions on the use of de-icing chemicals to help protect aquatic life and drinking water quality without ever compromising public safety.”
“MDOT SHA leverages innovation, modernized tools and continual training for the responsible use of salt on the network,” said MDOT SHA Administrator Greg Slater. “The health of the Chesapeake Bay watershed and Maryland’s environment is something we all value, and we prioritize that philosophy as we balance treatment of the roads for safety and an overall reduction in salt usage.”
Clearing roads and highways of ice and snow helps to ensure safe travel and the timely transportation of goods and services to keep Maryland’s economy moving. Sodium chloride – or salt – is effective, relatively inexpensive, readily available and easily stored. But salt can destroy a soil’s structure and cause erosion, can damage and kill vegetation and can contribute to the corrosion of metal bridges and motor vehicles. It can also seep into groundwater and run off into surface waters, contaminating wildlife habitat and potentially affecting drinking water.
Some Maryland streams are identified as being polluted by chlorides, which affects freshwater aquatic life. MDE has increased monitoring for chlorides to gain information that can be used in developing restoration plans.
Salt in drinking water can be a health threat to people on sodium restricted diets due to concerns about high blood pressure. Chloride can add a salty taste to water and corrode pipes. Road de-icing can cause increases in sodium and chloride concentrations in drinking water reservoirs, rivers that are sources of drinking water and private and public water system wells.
MDOT SHA has moved to using proactive strategies to reduce road salt use. The agency uses salt brine – a liquid solution that is 22 percent salt and 78 percent water – before, during and after winter weather events. Pre-treating roads with brine prevents the initial bonding of snow or ice, giving road crews time to mobilize. The agency now has three “tow plows” – separate plows towed behind a salt/plow truck to clear an additional travel lane – which enhances snow clearing operations. More plowing means less salting.
MDOT SHA has also designated routes where only salt brine is used for the duration of a storm, using less salt overall when compared to routes where rock salt is used. The agency pre-wets rock salt to reduce the “bounce and scatter” effect of salt solids ricocheting off the highway. MDOT SHA also works with weather forecasters to develop a treatment plan and employs nearly 100 infrared sensors at key locations, along with mobile sensors, to determine conditions and target its storm deployment – greatly contributing to salt reduction efforts.
MDE, in addition to its work to monitor streams to help improve water quality, has issued municipal stormwater permits to the largest local jurisdictions that include requirements for programs to reduce winter de-icing materials used. The next round of municipal stormwater permits will build on the lessons learned to require improved road salt management strategies and additional water monitoring plans to measure environmental progress.
Many Maryland residents use salt to reduce ice accumulation on steps, walkways and driveways. In addition to the effects on water quality and vegetation, de-icers can also be dangerous for children and pets. Tips for reducing or eliminating the use of excessive de-icers at home include:
- Clear walkways and other areas before the snow turns to ice to avoid the need for chemical deicers.
- Track the weather and only apply deicers when a storm is imminent. If a winter storm does not occur, sweep any unused material and store it for later use.
- Only use de-icers in areas where they are critically needed and apply the least amount necessary to get the job done.
- Store de-icing materials in a dry, covered area to prevent runoff.
- Reduce salt use by adding sand for traction, but take care to avoid clogging storm drains. Natural clay cat litter also works well.
- If your source of drinking water is your own private well, avoid applying salt near the well head.
- Don’t use urea-based fertilizers as melting agents. Runoff can increase nutrient pollution