e SPR 691 OCTOBER 2015 Development of ADOT Application Rate Guidelines for Winter Storm Management of Chemical Additives through an Ambient Monitoring System Arizona Department of Transportation Research Center Development of ADOT Application Rate Guidelines for Winter Storm Management of Chemical Additives through an Ambient Monitoring System SPR‐691 October 2015 Prepared by: Ed Latimer, Richard Bansberg, Scott Hershberger, Theresa Price, Don Thorstenson, and Phil Ryder AMEC Environmental & Infrastructure 4600 E. Washington St., Suite 600 Phoenix, AZ 85034 Published by: Arizona Department of Transportation 206 S. 17th Ave. Phoenix, AZ 85007 In cooperation with U.S. Department of Transportation Federal Highway Administration Disclaimer This report was funded in part through grants from the Federal Highway Administration, U.S. Department of Transportation. The contents of this report reflect the views of the authors, who are responsible for the facts and the accuracy of the data, and for the use or adaptation of previously published material, presented herein. The contents do not necessarily reflect the official views or policies of the Arizona Department of Transportation or the Federal Highway Administration, U.S. Department of Transportation. This report does not constitute a standard, specification, or regulation. Trade or manufacturers’ names that may appear herein are cited only because they are considered essential to the objectives of the report. The U.S. government and the State of Arizona do not endorse products or manufacturers. Technical Report Documentation Page 1. Report No. 2. Government Accession No. 3. Recipient's Catalog No. FHWA‐AZ‐15‐691 4. Title and Subtitle 5. Report Date Development of ADOT Application Rate Guidelines for Winter Storm October 2015 Management of Chemical Additives through an Ambient Monitoring 6. Performing Organization Code System 7. Author 8. Performing Organization Report No. Ed Latimer, Richard Bansberg, Scott Hershberger, Theresa Price, Don Thorstenson, Phil Ryder 9. Performing Organization Name and Address 10. Work Unit No. AMEC Environmental & Infrastructure 4600 E. Washington Street, Suite 600 11. Contract or Grant No. Phoenix, AZ 85034‐1917 DT11‐003009 12. Sponsoring Agency Name and Address 13. Type of Report & Period Covered Arizona Department of Transportation 206 S. 17th Avenue 14. Sponsoring Agency Code Phoenix, Arizona 85007 15. Supplementary Notes Prepared in cooperation with the U.S. Department of Transportation, Federal Highway Administration 16. Abstract The Arizona Department of Transportation (ADOT) is responsible for keeping state and federally owned/operated transportation corridors safe and operational during winter months when snow and ice accumulate on these roads. A common practice is the application of anti‐icing and deicing chemicals, primarily sodium chloride (salt). ADOT’s Winter Storm Management Operations Manual (WSMOM) presents guidelines for the application of anti‐icing and deicing chemical based on specific storm events and roadway conditions. Sodium and chloride can be dispersed to areas adjacent to roadways though melting snow and ice and by vehicle splash and spray. Upon reaching vegetation and soil, these compounds can negatively impact the environment. To evaluate the relationship between salt applications and potential impacts to soil and vegetation, data from winter storm management activities (frequency of application, quantity of salt applied, and adherence to ADOT WSMOM guidelines) were compared to sodium and chloride concentrations in soil and vegetation samples collected at varying distances from the roadway. Data collection and review included 16 sites along State Route 260 and U.S. Routes 180 and 191, all in ADOT’s Globe District. Analyses of soil and vegetation samples show that sodium concentrations are greatest nearest the roadway and decrease with increasing distance from the roadway. There is no evidence that sodium concentrations in the soil exceed levels considered tolerable for vegetation, nor is there a significant seasonal difference between fall readings and spring readings of sodium and chloride concentrations in soil and vegetation. Additionally, sodium concentrations in soil samples did not appear to have a statistically significant impact on the level of sodium in vegetation samples. Therefore, it cannot be concluded that sodium concentrations in soil are directly impacting sodium concentration in vegetation near the roadway. There is no evidence to support that ADOT should deviate from its current chemical application rate guidelines. 17. Key Words 18. Distribution Statement 23. Registrant's Seal Application rate guidelines; winter storm Document is available to the U.S. management; road salt; sodium concentration, Public through the National chloride concentration; ambient monitoring Technical Information Service, system; anti‐icing; deicing Springfield, Virginia 22161 19. Security Classification 20. Security Classification 21. No. of Pages 22. Price Unclassified Unclassified 113 SI* (MODERN METRIC) CONVERSION FACTORS APPROXIMATE CONVERSIONS TO SI UNITS Symbol When You Know Multiply By To Find Symbol LENGTH in inches 25.4 millimeters mm ft feet 0.305 meters m yd yards 0.914 meters m mi miles 1.61 kilometers km AREA in2 square inches 645.2 square millimeters mm2 ft2 square feet 0.093 square meters m2 yd2 square yard 0.836 square meters m2 ac acres 0.405 hectares ha mi2 square miles 2.59 square kilometers km2 VOLUME fl oz fluid ounces 29.57 milliliters mL gal gallons 3.785 liters L ft3 cubic feet 0.028 cubic meters m3 yd3 cubic yards 0.765 cubic meters m3 NOTE: volumes greater than 1000 L shall be shown in m3 MASS oz ounces 28.35 grams g lb pounds 0.454 kilograms kg T short tons (2000 lb) 0.907 megagrams (or "metric ton") Mg (or "t") TEMPERATURE (exact degrees) oF Fahrenheit 5 (F-32)/9 Celsius oC or (F-32)/1.8 ILLUMINATION fc foot-candles 10.76 lux lx fl foot-Lamberts 3.426 candela/m2 cd/m2 FORCE and PRESSURE or STRESS lbf poundforce 4.45 newtons N lbf/in2 poundforce per square inch 6.89 kilopascals kPa APPROXIMATE CONVERSIONS FROM SI UNITS Symbol When You Know Multiply By To Find Symbol LENGTH mm millimeters 0.039 inches in m meters 3.28 feet ft m meters 1.09 yards yd km kilometers 0.621 miles mi AREA mm2 square millimeters 0.0016 square inches in2 m2 square meters 10.764 square feet ft2 m2 square meters 1.195 square yards yd2 ha hectares 2.47 acres ac km2 square kilometers 0.386 square miles mi2 VOLUME mL milliliters 0.034 fluid ounces fl oz L liters 0.264 gallons gal m3 cubic meters 35.314 cubic feet ft3 m3 cubic meters 1.307 cubic yards yd3 MASS g grams 0.035 ounces oz kg kilograms 2.202 pounds lb Mg (or "t") megagrams (or "metric ton") 1.103 short tons (2000 lb) T TEMPERATURE (exact degrees) oC Celsius 1.8C+32 Fahrenheit oF ILLUMINATION lx lux 0.0929 foot-candles fc cd/m2 candela/m2 0.2919 foot-Lamberts fl FORCE and PRESSURE or STRESS N newtons 0.225 poundforce lbf kPa kilopascals 0.145 poundforce per square inch lbf/in2 *SI is the symbol for the International System of Units. Appropriate rounding should be made to comply with Section 4 of ASTM E380. (Revised March 2003) CONTENTS EXECUTIVE SUMMARY .................................................................................................................................. 1 Recommendations ........................................................................................................................... 1 Conclusion ........................................................................................................................................ 2 CHAPTER 1. INTRODUCTION ................................................................................................................... 3 Purpose of Study .............................................................................................................................. 3 Study Area ........................................................................................................................................ 4 ADOT Winter Storm Policies and Procedures .................................................................................. 4 Environmental Concerns .................................................................................................................. 5 CHAPTER 2. BACKGROUND ..................................................................................................................... 7 Western Region DOT Guidelines ...................................................................................................... 7 Summary of DOT Guidelines ............................................................................................................ 8 Best Management Practices .......................................................................................................... 11 CHAPTER 3. REVIEW OF CASE STUDIES ................................................................................................. 13 Literature Review ........................................................................................................................... 13 CHAPTER 4. METHODOLOGY ................................................................................................................ 21 Study Sampling and Analysis Plan .................................................................................................. 21 Field Sampling ...............................................................................................................................