Center for Environmental Excellence by AASHTO CENTER HOME  
skip navigation
CEE by AASHTO Home | Compendium Home | Online Compendium Help | Recent Updates | Inquiries | FAQs | State DOT Links
About Best Practices | Comment on Best Practices | Suggest A Best Practice | Volunteer to Vet Best Practices
Printer Friendly Version Print This Page    
 
« Back to Chapter 7 | Go to Chapter 9 »
Chapter 8 (Revised August 2013)
Winter Operations and Salt, Sand, and Chemical Management
8.7. Winter Operations Facilities Management

8.7.1 Materials Storage
< back to top >

Sand, liquid and solid products should be stored in a manner to minimize any contamination of surface or ground water. In general:

  • As previously discussed, all known runoff receptors should be inventoried and protected.
  • Care should be taken to prevent runoff from tanks or treated stockpiles.
  • Stockpiles of winter materials should be maintained according to best management practices.
  • Covered storage for dry/solid products is preferred.
  • Low permeability pavements that are sealed, impermeable pavements and plastic liners that provide containment under and around the sides of the solid stockpiles can reduce the long term-loss of product.
  • All usage of sand, liquid and solid products should be continuously and accurately recorded.
  • Vehicle wash water should be managed, either treated or re-used.
  • Knowledge of local environmental regulations specific to material storage is recommended.

Practical considerations include: noting the prevailing winter wind direction and positioning building and doors with regard to sheltering loading operations, minimizing snow drifting around doorways, keeping precipitation out of the storage areas; avoid spillage during stockpiling and truck loading; etc. (TAC, 2003). Specific information on pile size and storage capacity, loading and storage styles and techniques can be found in The Salt Storage Handbook (Salt Institute, 2006).

Environmental stewardship practices for operation of maintenance facilities and maintenance of stockpiles are reviewed in Chapter 6 on Facilities.

8.7.2 Management of Snow Disposal Sites
< back to top >

The most efficient way to dispose of snow is to let it melt where it accumulates, but where space is limited snow can be transported to a designated disposal site where it can melt on its own or with a snow melter (TAC, 2003). When choosing a location to operate a snow disposal site some things to consider include:

  • Minimizing the impacts on the natural environment and control nuisance effects, including noise, dust, litter and visual intrusion on adjacent landowners.
  • Manage the discharge of meltwater to comply with local water quality regulations and protect surface and groundwater resources.
  • Collect and dispose of onsite litter, debris and sediment from the meltwater in accordance with local waste management legislation.
  • Snow handling, storage and disposal design should be practical (TAC, 2003).

Routine monitoring of the site including meltwater capacity, collection, and retention and discharge systems may be considered, including periodic collection of water and soil samples. This can be done using onsite monitoring equipment or samples can be sent to an accredited laboratory. If retention ponds are being used to hold meltwater, consider annual cleaning of the ponds to maintain capacity to handle the worst case year snow load (TAC, 2003).

The Municipality of Anchorage (MOA) conducted a four-year study (1998-2001) of snow disposal sites and found three factors that related to how pollutants are released during snow melting:

  • The initial source of hauled snow,
  • The melt processes of stored snowfall, and
  • The shape of the snow storage areas and the snowfills (Wheaton and Rice, 2003).

The study concluded that:

  • Chlorides can be controlled passively through detention and dilution.
  • Mobilization of metals and polynuclear aromatic hydrocarbons relates to chloride concentration, but a large fraction can be controlled with particulate capture.
  • Particulate loading in melt water relates to the shape of the snow fill and the pad on which it is situated and can be controlled by manipulation of these elements.

The City of Toronto uses stationary and mobile snow melters when they run out of the capacity to store the snow until it melts on its own (not necessarily every year) (personal communication, P. Noehammer, March 28, 2012). They have dealt with several important issues:

  • Treating all snow melt as stormwater runoff and handling it appropriately.
  • Consider site grading for appropriate drainage.
  • In the snow melt filtering processes, removing all the grit and oils and picking up all the debris.
  • The snow melters are burning hydrocarbons and so there are associated emission and noise issues that need to be dealt with (e.g., location should be considered).

8.7.2.1 Site Security and Environmental Controls

The sites should be secured to avoid illegal dumping, prevent unauthorized access, by both humans and animals, for safety reasons and to permit safe efficient operation of the site. Security and environmental considerations include:

  • Delineation of the site boundary using perimeter fencing with appropriate signage and a gate with controlled access.
  • Provision of adequate lighting for operations, with the lights focused away from adjacent land uses.
  • Provision of low permeability berms (with or without trees) around the site to prevent uncontrolled offsite release of meltwater. These berms and additional landscaping can also mitigate noise, litter, and visual impacts.
  • Use of low permeable surfaces at the site.
  • Avoiding spillage during stockpiling and truck loading, and encourage prompt clean-up when spills occur.

8.7.2.2 Site Management

Ensure that a single individual is assigned responsibility for the operation of the site and is accountable for its operation and environmental performance.

  • Litter control:
    • With any snow removal and disposal operation a significant amount of small, lightweight debris will be collected and dumped along with the snow. This litter is blown around by the wind and can be a problem both on and offsite.
    • Staff should collect litter regularly to prevent it from blowing onto adjacent properties.
    • The installation of a net or fence around the perimeter of a snow disposal facility can help contain the litter within the site.
    • All debris in the snow storage area should be cleared from the site prior to snow storage.
    • Collect and dispose of onsite litter, debris and sediment from the meltwater settling area in accordance with local waste management legislation.
    • All debris in the snow storage area should be cleared from the site and properly disposed of each spring by the conclusion of the winter season.
  • If a municipality provides locations for private contractors to deposit snow, they should require disposal according to these recommendations.
  • Control emissions (drainage, noise, dust, litter, fumes) to prevent offsite environmental impacts.

8.7.2.3 Pile and Meltwater Management

  • Efficient flow of meltwater to the collection area should be maintained.
  • Placing snow in high, compact masses with steep sides all around minimizes the exposure of accumulating sediment on the snowfill surface to seepage and flow.
  • Placing snow in a single snow mass rather than several isolated masses reduces exposure of sediment to up-gradient meltwater sources. Sites can also be operated to take advantage of aspect, with snow placed as compact masses at northernmost down-gradient locations so that a snowfill will preferentially recede from uphill to downhill. This practice will reduce exposure of down-gradient sediment to meltwater flows as the sediment settles to the pad surface in the final stages of melt (and becomes most vulnerable to erosion).
  • Rutting caused by heavy trucks should be kept to a minimum or repaired quickly.
  • Fast flowing, high volume channels of meltwater should not be allowed to develop near the piles, to avoid excessive erosion and rutting of the driving and snow pile surface.
  • Sheet flow of meltwater under and near the piles is preferred.
  • Avoid blowing, pushing or dumping snow into the watercourse.
  • Place hauled snow over the full width of each swale. Sequence placement of snow starting at the downslope side and working upslope.
  • Maintain snow in a compact mass with steep sides.
  • Maintain setback from all containment berms and from the discharge end of V-swales.
  • Maintain pad vegetative cover and re-grade only to ensure V-swale functionality.
  • Restrict access and prohibit off-season traffic and on-snow storage uses.

8.7.2.4 Monitoring

All parties involved should recognize that snow disposal sites will have an impact on the environment. Most activities should be focused on minimizing or mitigating the impacts.

Monitoring of snow disposal sites aids in the determination of the extent of the impacts, the effectiveness of the mitigation measures taken, and allows for adjustments that can be made.

  • Baseline condition (benchmarking) of site and surrounding area for future monitoring comparisons should be completed prior to the site being commissioned. Contaminant levels recorded once the site is operational will have to be compared to levels prior to the site opening to give a true indication of any environmental impacts.
  • Contamination levels may be monitored at various points around the site and surrounding area. Various factors can affect the number and location of monitoring points including - urban vs. rural location, intensity of site use, size of site, and local requirements.
  • Where warranted some or all of the following locations may be monitored:
    • Beneath the site (ground water and soil).
    • Above and around the site (where air quality is an issue).
    • In the snow being dumped.
    • In the melting snow piles.
    • In the collected melt water.
    • At the discharge site and in the discharged melt water.
    • Upstream (for comparison) and downstream of the discharge site (in the receiving area or mixing zone).
    • In the ground water downstream or downflow of the discharge site.

There are numerous potential contaminants that can be monitored. Important contaminants from a salt management perspective include chlorides, sodium, pH, - metals, Total Petroleum Hydrocarbons (TPH), and suspended solids (TAC, 2003). Additionally if agriculturally derived products are being used consider testing the melt water for biological oxygen demand (BOD) and potentially their co-products.

8.7.2.5 Site Operation

  • The efficiency and remaining capacity of the meltwater collection and treatment areas need to be monitored. Over time the collection and treatment ponds will silt-up reducing their capacity and ability to handle the meltwater. Regular removal of the material that has settled out will significantly extend the life of the areas.
  • The stability and condition of the snow storage and driving surface. If the surface deteriorates significantly a site may become unusable until major repairs are done.

8.7.2.6 Record Keeping

The following list includes items and issues for which records should be kept:

  • General site information:
    • Number of snow disposal sites and their capacity.
    • Snow disposal site run-off collection and/or treatment system(s).
    • Snow disposal sites with a monitoring program (groundwater, surface soil, etc.).
  • The volume of snow dumped and when it was dumped.
  • An estimate of the melt rate. Can use estimate of volume of snow left, flow into meltwater collection and treatment system or discharge volume. A record of basic atmospheric data is useful in helping to determine the melting rates.
  • Debris volume and type. Some sites have instituted a lost and found so residents and businesses can retrieve items such as mailboxes, garbage cans, signs, etc.
  • Contaminant monitoring records (point data, trends, levels, etc.). Benchmark and contaminate monitoring data may need to be kept on file even after the site has been decommissioned. Monitoring records may be subject to periodic audits and third party reviews and need to be kept appropriately.
  • Maintenance and operation records.
    • Regularly review site operations and look for ways to improve efficiency of dumping, pile management and melting.
    • Look for ways to reduce debris and litter by tracking type and source.
< back to top >
 
Continue to Section 8.8 »
 
Table of Contents
 
Chapter 8
Winter Operations and Salt, Sand, and Chemical Management
8.0 Introduction
8.1 Selecting Snow and Ice Control Materials to Mitigate Environmental Impacts
8.2 Reducing Sand Usage and Managing Traction Materials
8.3 Strategic Planning for Reduced Salt Usage
8.4 Stewardship Practices for Reducing Salt, Sand and Chemical Usage
8.5 Precision Application to Manage and Reduce Chemical Applications
8.6 Monitoring and Recordkeeping
8.7 Winter Operations Facilities Management
8.8 Training for Salt Management and Winter Maintenance Operations
  References
  Appendix A - Acronyms
   
Lists: Examples | Tables | Figures
Website Problems Report content errors and/or website problems
PDF Document Download Adobe Acrobat Reader