Winter maintenance, chlorides and parking lots: Managing more with less!

1. Dr. M. Stone Department of Geography and Environmental Management University of Waterloo Partnering for Snow Management Success2010 Snow and Ice Symposium Mississauga, Ontario Winter maintenance, chlorides and parking lots: Managing more with less!

2. Overview • Road Salt and the Environment • Winter Maintenance and Parking Lots • Clarkson Go Station Parking Lot Study • Smart About Salt Program • Barriers to Implementation

3. Impacts of road salt on source water Mass loading influenced by: Season Road type/class Snow clearing practices Drainage infrastructure Subsurface geology Lawn watering Highly spatially and temporally heterogeneous.

4. Historical Context Canadian Environmental Protection Act, 1999 (Environment Canada, 2001) – significant losses of chloride from road salt adversely impact - freshwater ecosystems - terrestrial ecosystems (soil, vegetation & wildlife) - drinking water supplies http://www.ec.gc.ca/substances/ese/eng/psap/final/roadsalts.cfm

5. Historical Context Code of Practice for the Environmental Management of Road Salt, 2004 Designed to help municipalities/authorities better manage salt use to reduce adverse environmental impacts of chloride while maintaining road safety. http://www.tac-atc.ca/english/resourcecentre/roadsalt.cfm

6. Historical Context Recommendations of the Code: 1. Develop salt management plans, based on a review of existing road maintenance operations, identification of means and goal setting to reduce the negative impacts of salt releases 2. Implement best management practices (BMPs) in areas of salt application, salt storage and snow disposal as reported in the Transportation Association of Canada’s (TAC) Syntheses of Best Management Practices.

7. Syntheses of Best Practices - Road Salt Management 1 Salt Management Plans 2 Training 3 Road and Bridge Design 4 Drainage and Stormwater Management 5 Pavements and Salt Management 6 Vegetation Management 7 Design and Operation of Road Maintenance Yards 8 Snow Storage and Disposal 9 Winter Maintenance Equipment and Technologies http://www.tac-atc.ca/english/resourcecentre/roadsalt.cfm

8. Historical Context Assumption: Voluntary, state-of-the-art salt management practices when applied as per Code recommendations will benefit the environment and road authorities by: - reduce chloride levels - improve water & soil conditions - increase operational efficiency - improve roadway safety - provide cost savings APPLIES TO ORGANIZATIONS THAT APPLY > 500 T SALT/YEAR

9. Mullaney, J.R., Lorenz, D.L., Arntson, A.D., 2009, Chloride in groundwater and surface water in areas underlain by the glacial aquifer system, northern United States: U.S. Geological Survey Scientific Investigations Report 2009–5086, 41 p. The link to the full report can be found on the NAWQA glacial aquifer system web page at: http://water.usgs.gov/nawqa/studies/praq/glacaq/index.html

10. Source: Mullaney et al (2009) USGS Scientific Investigations Report 2009–5086.

11. Groundwater Cl levels in the NE US Source: Mullaney et al (2009) USGS Scientific Investigations Report 2009–5086.

12. Groundwater Na levels in the NE US Source: Mullaney et al (2009) USGS Scientific Investigations Report 2009–5086.

13. Maximum Cl levels in NE US Mullaney et al (2009) U.S. Geological Survey Scientific Investigations Report 2009–5086, 41 p.

14. Historical Salt Loading Region of Waterloo

15. Greenbrook Well Field 0 5km

16. East West Greenbrook Well Field 0 5km

17. Waterloo Moraine Nith River Nith River GrandRiver 0 10 km Paul Martin, WHI

18. Greenbrook Well Field 10 year capture zone 0 1 km • 100 years of production history. • 5 wells pumping ~ 3 million gals/day. • average well depth, 180 ft. in glacial sediments. • progressive increase in Na and Cl concentrations • over past 30-40 years.

19. Chloride Concentration at the Greenbrook Well Field

20. Kitchener-Waterloo Road Network 1950 Greenbrook Well Field 2 km

21. Kitchener-Waterloo Road Network 2000 Greenbrook Well Field 2 km

24. ‘94 ‘98

25. Continuous Coring Well Installation Application of Bromide Tracer

26. Road Shoulder Profiles Water Table Well Screen Sarwar et al. 2002

27. Water Table Source Width Repeat Chloride Profiling Sarwar et al. 2002

30. Winter Maintenance and Parking Lots and Sidewalks

31. Over application of salt • Expectations of property owners for bare pavement • Lack of understanding of how deicers function • Fear of litigation

32. Improper drainage from buildings

33. Location of snow storage related to excessive salt application (Photograph by Bob Hodgins) Good example of snow storage(Photograph by Bob Hodgins)

34. Poor condition of pavement promotes loss of chloride by infiltration to the subsurface. (Photograph by Bob Hodgins)

35. Winter Parking Lot and Sidewalk Maintenance • Deicers melt snow and ice but provide no traction • Anti-icing prevents the bond forming between pavement and ice • Deicing works best if you plow before applying material • Pick the right material for the pavement temperature • Sand only works on top of snow as traction – provides no melting • Anti-icing chemicals must be applied before snowfall • Road salt does not work at temperatures < 15 º F

36. Melt times for salt (NaCl ) at different pavement temperatures

37. Melting Characteristics

38. Variables affecting application rates • Increase rate if • compaction occurs and cannot be mechanically removed • too much snow left behind • Decrease rate if • light snow on freezing rain • pavement temperature is rising • subsequent applications

40. Clarkson Go Station Parking Lot Study

41. 4 t of common road salt typically applied (~0.2 kgm-2) per event ~ 10 x the rate used on provincial roads Mountain Organic Natural Icemelter (~0.01 to 0.14 kg m-2)

42. GO 1 GO3

43. Conclusions • The hydrologic response from both parking lots was flashy and tightly coupled with the type and amount of precipitation inputs as well as the specific processes that induced the melt (i.e. chemical melt versus temperature induced melt). • The maximum discharge was 50 Ls-1 and 82 Ls-1 for the GO1 and GO 3 parking lots, respectively. • The event mean chloride concentration for the 26 monitored events was 14,561 mg L-1 and 6,816 mg L-1 for the GO 1 and GO 3 parking lots, respectively. • However, average chloride loads (g m-2) were higher by a factor of 2.3 for GO 1 (46 gm-2) compared to GO 3 (20 gm-2).

44. Leanne Lobe October 15/07

46. Salt Reduction Initiatives • Parking Lots and Sidewalks • Surveys • Barrier Analysis • Pilot studies • Guide to Salt Management • Self-assessment Tool • Salt Management Workshop

47. Sometimes less really is more • Safety is a priority • Building partnerships • Engaging the stakeholders • Overcoming the barriers • Identifying the motivators

48. 3 Years Designation Process Registered Company and/or Facility Snow Removal Contractor Certified Professional

49. Smart about Salt - Benefits • Insurance advantages • Access to data • Marketing opportunities • Program efficiency • Environmental stewardship • Leadership

50. Barriers to Implementation! • Lack of stakeholder interest/commitment • Lack of means • Lack of awareness and access to information • Dynamics of enforcement • Overcoming history and lack of experience • Lack of incentives for adoption of new technologies/actions • Inability to adapt • Uncontrollable external circumstances • Degree and speed of change