Central Massachusetts Regional Stormwater Coalition Part 7 Sand and Salt Calibration September 26, 2013 Community Innovation Challenge Grant 2013

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 Task Original: 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 Benchmarked Current Chloride Loading (pounds of chloride per lane-mile) Suggested Recommendation This loading rate is protective of water quality 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