Winter Snow and Ice Management Reducing environmental Impacts. Connie Fortin

Transcription

1 Winter Snow and Ice Management Reducing environmental Impacts Connie Fortin

2 What s the problem?! %1

3 We have a limited supply of freshwater Less than 1% is available to us

4 How does salt impact the environment?

5 The U.S. Government has standards for pollutants Chronic standard for Chlorides: 230 mg/l = 1 teaspoon salt in 5 gallons water

6 1 tandem load of salt can easily contaminate 8 million gallons of water YIKES!

7 Chloride levels in twin city metro area ground water was among the greatest in the 29 urban areas studied in the United States. ( USGS)

8 Alters the seasonal turnover of our lakes Mixed waters Too heavy with salt Won t mix properly

9 The trend toward increased salinity of urban lakes appears to be strongest in inner city lakes (Novotny et al. 2007)

10 1 ton of rock salt ($50) causes greater than $1,450 in corrosion damage to bridges, vehicles, and environment (TRB Report) Ali Akbar Sohanghpurwala- Road Salt Symposium 2008 (photo and fact)

11 Shingle Creek in Hennepin County. First creek in MN listed for chlorides. 71% reduction is required

12 Chloride impairments in 2010 draft list: Miller Creek - Lake superior Basin Bass Creek - Upper Miss. Basin Bassett Creek Battle Creek Crow River, South Fork Jewitts Creek Minnehaha Creek Shingle Creek Unnamed creek Bevens Creek - MN River Basin Nine mile Creek Raven Stream Raven Stream, East Branch Redwood River Sand Creek Joe River Red River Basin " 1

13 We have a serious problem but we also have many ways to reduce impacts.

14 The total amount of road salt applied in TCMA is approximately 350,000 tons per season. "Research by Eric Novotny, Andrew Sander, Omid Mohseni and Heinz Stefan at SAFL, University of Minnesota, and sponsored by LRRB/MNDOT". Polluting about 200 billion gallons of water each year Fortin Consulting

15 Best Practices Information that you, as a leader, should know. Excerpts from the training class

16 All salt and winter sand piles should be placed on a waterproof base and covered. Source of groundwater contamination

17 Use heat not chemicals to open storm drains

18 Anti-icing is the light application of a liquid de-icer prior to a storm IT IS THE FUTURE!

19 Pavement Invest in Anti-icing technology. It is proactive. It will prevent a bond from forming between the road and the ice. Ice

20 Pavement Traditional De-icing It will take 10 times more work and/or 4 times more chemical to break a bond than to prevent a bond Ice

21 Progressive maintenance includes Wet Salt

22 Salt Retrieved from 24ft. pavement 12% 78% P r e - w e t 46% D r y 9% 9% 12% Unretreived salt 4% 30% Michigan Highway Department Outside 1/3 Center 1/3 Outside 1/3

23 GET SALT WET It increases the speed of melting! You get faster results with less WOW

24 Potential Cost Savings Hypothetical Example: Material Cost/ton Amt. needed Total cost Dry salt $70 10 tons $700 Wet salt $ tons $594

25 Rock salt is not for cold temps Pavement Temperature º F One Pound of Salt (NaCl) Melts 46.3 lbs of ice 14.4 lbs of ice 8.6 lbs of ice 6.3 lbs of ice 4.9 lbs of ice 4.1 lbs of ice 3.7 lbs of ice 3.2 lbs of ice Melt Times 5 min. 10 min. 20 min. 1 hour Dry salt is ineffective and will blow away before it melts anything

26 How much de-icer do I need? Follow these steps.

27 1. Calibrate equipment every year.

28 2. Know pavement temps

29 Try application rates in training manual Application Rate in Lbs/per 1000 square foot area Weather Condition Maintenance Actions Salt Prewetted/ Pretreated With Salt Brine Salt Prewetted/ Pretreated With Other Blends Dry Salt Winter Sand (abrasives) Pavement Temp. (ºF) and Trend (!") >30! Snow Plow, treat intersections only not recommended Frz. Rain Apply chemical not recommended 30 " Snow Plow & apply chemical not recommended Frz. Rain Apply chemical not recommended 25-30º! Snow Plow & apply chemical not recommended Frz. Rain Apply chemical not recommended

30 Training Results

31 In Class survey of Best Practices averaged from 14 training classes BMPs already followed 31% New BMPs that will be tried 45% Total BMPs adopted 76%

32 In Class Rate Reduction Exercise averaged 18 road training classes 2008/2009 Average potential reduction in salt rates 36% *For 2008/2009 parking lot/sidewalk training classes average potential reduction was 63%

33 Rock salt: 617 tons (68%) MgCl 2 : 80 tons (65%) Photo taken by Bobak Ha Eri

34 U of M in one year saved $55,000) MATERIAL #3 - SAND 1997 to 2005 avg 1965 tons 1997 to 2005 avg 18 tons Net Reduction: 1947 tons % Reduction: 99% MATERIAL #1 - ROCK SALT 1997 to year avg: 775 tons of salt 2006 to 2008 avg : 462 tons of salt Net avg. Reduction: 313 tons % Reduction: 41% MATERIAL #2 - ICE MELT (Magnesium Chloride - MgCl2) 1997 to 2005 avg: 131 tons 2006 to 2008 avg: 64 tons Net avg Reduction: 67 tons % Reduction: 51%

35 You can help! Educate the public - we are paying for instantly clear roads with our lakes and drinking water Very little activity in this area Constantly requested by maintenance workers at our training classes No better group than Watershed Partners to take this on!

36 Winter Maintenance for Homeowners

37 Encourage training of snow and ice professionals

38 Take the pressure off of public works

39 Use less salt yourself

40 Look out 10 years can we help promote non-chemical methods for winter maintenance

41 Questions & Discussion