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Part 7 Sand and Salt Calibration September 26, 2013. Community Innovation Challenge Grant 2013. Why did CMRSWC Address This?. Focus on chloride impairments is strong in NH, along I-93 corridor. Increased R&D into new deicing materials and methods in recent years. - PowerPoint PPT Presentation
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Central Massachusetts Regional Stormwater Coalition
Part 7
Sand and Salt Calibration
September 26, 2013
Community Innovation Challenge Grant2013
Central Massachusetts Regional Stormwater Coalition
Why did CMRSWC Address This?
1. Focus on chloride impairments is strong in NH, along I-93 corridor.
2. Increased R&D into new deicing materials and methods in recent years.
3. Project partner Oxford, MA had developed detailed calibration procedure, reduced total chloride application and cost. Other Towns interested in learning how they did it.
Central Massachusetts Regional Stormwater Coalition
Objectives of the TaskOriginal: • Develop a “decision tree” that would use information
such as traffic conditions, pending weather, ambient temperature, and material melting temp to recommend loading (lbs per lane mile)
Revised: • Captured “decision tree” information done
elsewhere.• Developed “rough” loading estimate. • Documented Oxford’s detailed procedure.
Central Massachusetts Regional Stormwater Coalition
“Rough” Loading Estimate
• Input required for method: - Total material used in year (tons and gallons)- Total lane-miles managed- Number of storm days (days deicing was completed)
• Output: estimated pounds of chloride per lane mile.
Disadvantages: doesn’t account for variation in loadings from different vehicles or differences in storm
events; storm days not always known.
Central Massachusetts Regional Stormwater Coalition
“Rough” Loading Estimate: Example
Central Massachusetts Regional Stormwater Coalition
Calibrated Loading Calculation• Benchmarks loading from each vehicle; sum entire
fleet• Input required for method:
- Material weight/volume, distance traveled in one trip, and settings on each device for that vehicle.
- Alternately: set up tarp, time device for five minutes and extrapolate.
• Output: estimated pounds of chloride per lane mile for that vehicle.
Disadvantage: Time consuming.Advantage: Very accurate.
Central Massachusetts Regional Stormwater Coalition
Calibrated Loading Calculation: Example
Central Massachusetts Regional Stormwater Coalition
Once Application is BenchmarkedCurrent Chloride Loading(pounds of chloride per
lane-mile)
Suggested Recommendation
0 - 300 This loading rate is protective of water quality.
301 - 500
This loading rate is above-average.It is likely that chloride loading can be reduced without
adversely impacting public safety.Re-calibrate equipment to deliver 90% of current loading rate.
Make additional reductions on an iterative basis.
> 500
This loading rate is elevated.It is likely that chloride loading can be reduced without
adversely impacting public safety.Re-calibrate equipment to deliver 80% of current loading rate.
Make additional reductions on an iterative basis.
Central Massachusetts Regional Stormwater Coalition
Calibrated Loading Calculation
• Choose a target delivery rate. • Review and document settings on each application
device on vehicle. • Adjust settings to reduce delivery toward target. • Test reduced delivery rate during storm event, ensure
that public safety is not impacted. • Continue to recalibrate and make additional
reductions on an iterative basis.
Central Massachusetts Regional Stormwater Coalition
Other Salt Application Resources
Minnesota “Clipboard
Sheet”
Central Massachusetts Regional Stormwater Coalition
Other Salt Application Resources
Cornell Application
Rates
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