As snow melts, it is considered stormwater runoff, transporting road salt, sand litter, and other pollutants into surface water or through soil leading to groundwater, polluting waterways and drinking water supplies. But of course, making walking and driving areas safe is of high importance. Is it possible to maintain stormwater runoff quality while at the same time sustain safe conditions for pedestrians and vehicles? It is through a combination of using deicing alternatives and managing snow melt runoff.
Impacts of Salt and Sand
Salt and sand are the most common and least expensive materials for de-icing outdoor surfaces. However, they do have a negative environmental impact. Salt depletes the oxygen supply in waterways, leaches into the ground and changes soil composition, leaches into groundwater which may affect drinking water supplies, and deteriorates paved surfaces, building, and the environment. Sand can collect on aquatic floors, filling in habitats and clouding the water; erode stream banks; cause premature deterioration of floor surfaces as it is tracked into buildings; enters catch basins, storm drains, and surface waters; and contributes to plugged storm drains, potentially causing flooding.
Disposing of Snow
Municipalities and private industry often have to remove snow from their premises, and find a place to dispose of the collected snow. When selecting a site for snow disposal:
- Avoid dumping snow into any waterbody, including rivers, reservoirs, ponds, lakes, wetlands, bays, or the ocean.
- Do not dump snow within wellhead protection areas of a public water supply or within 200 feet of a private well.
- Avoid dumping snow in sanitary landfills and gravel pits, where there is little opportunity for filtration.
- Avoid disposing of snow on top of snow drain catch basins or in stormwater drainage swales or ditches, where sand and debris in the melting snow may block a storm drain, causing localized flooding.
After a disposal site has been selected, the site should be prepared:
- A silt fence or equivalent barrier should be placed on the downgradient side of the site.
- A vegetative buffer strip should be maintained during the growth season between the disposal site and adjacent water bodies to filter pollutants out of the meltwater.
- Debris should be cleared from the site before disposal.
Preparing Construction Sites
Construction sites often are temporarily closed during winter weather. Site preparations need to be completed before frozen conditions set in so that protection is in place during winter thaws and spring snow melt.
- Plant seed for spring which will help to stabilize soil, preventing erosion
- Repair silt fences and other sediment controls
- Clean sediment out of storm ditches, sediment basins, and stormwater inlets
- Cover all exposed soils with mulch
- Stabilize ditch bottoms
And remember, best management practices for dealing with runoff from snowmelt should be documented in construction site Stormwater Pollution Prevention Plans.
Considering Alternatives to Salt and Sand
There are alternative deicing chemicals that are more environmentally friendly than sand and salt, according to the U.S. Environmental Protection Agency. These alternatives include calcium chloride, magnesium chloride, calcium magnesium acetate, and products that are mixtures of chlorides and organic compounds.
Municipalities and facilities should also be looking to the future, and integrate green design, known as low impact development (LID), into their current infrastructure. For instance, porous pavement, which contains pore spaces that store and allow runoff to infiltrate into the ground, lasts twice as long as conventional asphalt and speeds snow and ice melt, dramatically decreasing the amount of road salt needed in winter. Through the integration of new technology and alternatives and thoughtful planning, some of the negative environmental impacts of winter weather management can be prevented.
Amanda Czepiel, J.D., is a Legal Editor for BLR’s environmental law publications. Ms. Czepiel has over 6 years of experience as an attorney and writer in the field of environmental compliance resources and has published numerous articles on a variety of environmental law topics, including wastewater and NPDES permitting, brownfields and contaminated sites remediation, oil spill prevention, wetlands, and corporate sustainability. Before starting her career in publishing, Ms. Czepiel worked in hospitality consulting and for various non-profit organizations and government agencies in the environmental field. Ms. Czepiel received her law degree from the University of Connecticut School of Law.