Connie Fortin – Fortin Consulting Incwww.fortinconsulting.com
The Latest in Smart Snow and Ice Control
This talk is based on excerpts from the Minnesota voluntary certification program
www.pca.state.mn.us/programs/roadsalt.html
The Situation
SALT USE forSAFE TRAVEL
Permanently Polluted
Water
WINTER
How does salt affect our waters and what can we do about it?
Salt becomes invisible but it doesn’t disappear.
It mixes with water and stays in solution.
• Chronic standard for Chlorides:230 mg/l= 1 teaspoon salt in 5 gallons
water
The U.S. Government has standards for pollutants
National: Exceedances of EPA Water Quality Criteria for Cl
6739/5266 1383/995
# of Sites 12 6 21 6 29 15 7 7 11 12 17 14 5 19 22 6 3 162 50
Comparison of lake chloride concentrations in 39 Minnesota lakes and rock salt purchases by the state of Minnesota (Novotny et al. 2007).
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)
Working with the maintenance industry is the key to safe surfaces and clean water
Storage areas are #1 risk for ground water contamination. If your pile contaminates the ground water you will be held responsible
Store on impermeable pad and covered
Storage: Liquids
Be safe: Secondary containment
or double wall tanks
Plan for year round storage
Do not use salt just to get rid of it at the end of the winter.
How salt works
Speed of MeltingPavement
Temperature º FOne Pound of
Salt (NaCl) MeltsMelt Times
30252015
46.3 lbs of ice14.4 lbs of ice8.6 lbs of ice6.3 lbs of ice
5 min.10 min.20 min.1 hour
1050-6
4.9 lbs of ice4.1 lbs of ice3.7 lbs of ice3.2 lbs of ice
Dry salt is ineffective and will blow away before it melts
anything
Know the Lowest practical melting temperature for each material
Chemical Lowest Practical Melting Temp.
Eutectic Temp. Optimal Concentration
Sodium Chloride 15º F -6º F 23%Magnesium
Chloride -10º F -28º F 27 to 30%CaCl2 (Calcium
Chloride)-20º F -60º F 30%
CMA (Calcium Magnesium
Acetate)
20º F -18º F 32%
KAc (Potassium Acetate) -15º F -76º F 50%Blends Talk to supplier Talk to supplier Talk to supplier
Winter Sand/Abrasives
Never melts -- traction only
Never melts -- traction only
Use application rate tables! www.pca.state.mn.us/programs/roadsalt.html
Our rates are low, they are a good target, not a starting point
Calibration should be the backbone of
your snow and ice program!
Yearly Calibration
Pg 10
Calibration separates the top performing organization from the
average organizations
If you are applying materials with only your eyes to judge. Look for better ways!
500 300
Almost twice the rate doesn’t “look” that different
Many types of equipment can be calibrated:
Projected Results
Average potential reduction in salt application rates: 62% for parking lot/sidewalk
36% for roads
Integrating Liquids• Good for public safety• Improved performance• Cost effective• Better for the environment• IT IS IN YOUR FUTURE
The purpose of deicers is to prevent the bond from forming between the pavement and the
ice, not to melt the ice. We only need to melt this little layer
Pavement
Ice
Without the bond the plow, shovel or snow blower will do a great job
Pavement
Ice
It will take 10 times more work and/or 4 times more chemical to
break a bond than to prevent a bond
Pavement
Ice
Anti-icing – Applying liquids before the storm
EnviroTech
LCS
4 Hours Later
• The snow will accumulate but the surface underneath is wet
• The bond is weak
The time to get your site back after the
storm will be reduced if you anti-ice
You will not have trouble with frost if you have anti-iced
Anti-icing is like frying eggs
Wet salt increases the speed of melting! Salt can start working NOW, no delay.
Mixing liquids with dry salt
Center 1/3Outside 1/3 Outside 1/3
9% 9%12% 12%
4%
30%
46%
78%
Pre-wet
Dry
Salt Retrieved from 24ft. pavement Unretreived
salt
Michigan Highway Department
With wet salt you can use 30% less….just turn down your application rate.
Two good options for adding liquids:On the truck or on the Stockpile
Pre-wet Pre-treat
Potential Cost Savings
Hypothetical Example:
Material Cost/ton Amt. needed
Total cost
Dry salt $70 10 tons $700
Wet salt $90 6.6 tons $594
Rock salt: 617 tons (68%)MgCl2: 80 tons (65%)
Photo taken by Bobak Ha’Eri http://creativecommons.org/licenses/by-sa/2.5/
Mississippi River
Saved $55,000 the first year
Reduced:
Road salt 41%
Mag chloride 51%
Sand 99%
1 year after Training:
Actual Results
• As for the state budget…The salt savings at the U of MN alone in one year ($55,000) more than paid for one year of training across the state.
Minnesota’s Next Steps
Twin Cities Metro Area Chloride Management Plan
•Minnesota is developing a Twin Cities metro area chloride management plan. Emphasizing working partnerships between industry and environment
•Will result in better understanding of our lakes and rivers
•Based on water quality information salt reduction targets will be given based on geographic areas (2014). They will be formulated to protect good water and to restore polluted water
•Tools are being developed to help organizations assess their operations and move towards lower impact practices
•No practices will be mandated. Maintenance operations will have flexibility in making changes appropriate to their organizations to achieve salt reduction targets.
For more information contact: Brooke Asleson MPCA Project Manager: 651-757-2205 [email protected] www.pca.state.mn.us/oxpg9f1
Housekeeping Section:Chart your current and near future practices
Now Near Future
Practices Internal Code
internal calculation
Bulk salt pile uncovered
1 Move from 1 to 2 = 1% reduction
Bulk salt pile tarped
2 Move from 1 to 3 = 5% reduction
Bulk salt pile indoors
3
standard best practice
Advanced best practice
Remedial practice
Move from 2 to 3 = 5% reduction
What type of training is available in your area?
Can you provide useful tools to help maintenance professionals make better decisions?
The future is in our hands
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