PUBLIC WORKS DEPARTMENT 2198 GLENDALE AVENUE GREEN BAY, WI PAUL A. FONTECCHIO, P.E. PHONE (920) FAX (920) DIRECTOR bc_h

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68 PUBLIC WORKS DEPARTMENT 28 GLENDALE AVENUE GREEN BAY, WI PAUL A. FONTECCHIO, P.E. PHONE (920) FAX (920) DIRECTOR TO: FROM: PD&T Committee Paul Fontecchio, P.E. DATE: September 25, 2017 RE: Director s Report PROJECTS: Courthouse Dome: Copper continues to be placed and clock faces are being installed. The majority of the copper should be placed by the first week of October. The project in on schedule and on budget. West Side Transfer Station: On Friday August 25 th and Saturday August 26 th the excavation was performed for the Port and Resource Recovery Department at the west side transfer station. Asphalt paving took place the week of September 11 th. The entrance was widened and failing areas of the roadway were repaired. CTH D: On September 18 th concrete work began at the Hickory Road roundabout. Earthwork continues from Hickory Road to Barrington Drive. CTH HS: Resurfacing CTH HS from Glendale Ave. to CTH B is completed. WINTER HIGHWAY MAINTENANCE MANUAL: Attached please find the Brown County Public Works Winter Highway Maintenance Manual that will be distributed to highway crew employees this fall. TWELVE-HOUR DAYS: Highway Division: Highway incurred 1,771.0 hours of overtime in August. Substantially, all overtime was related to roadway maintenance/reconstruction projects. The amounts in excess of 12 hours per day for August are attached. Facility Management Division: Facilities incurred 87.5 hours of overtime in August. The overtime was related to longer cleaning shifts to cover vacancies and mechanical repairs. The amounts in excess of 12 hours per day for August are attached. STAFFING REPORT: See Attached Table.

69 Public Works - Highway Division 12-Hour Work Days 8/1/17-8/31/17 DATE EMPLOYEE OPERATION PREFORMED HOURS WORKED 8/1/2017 Dixon, Darrell Signing, Traffic Control for PBM-7 Rubber 12 8/1/2017 Goral, Nick State Rubber (PBM-7) 12 8/1/2017 Ledvina, Jason State Rubber (PBM-7) 12 8/1/2017 Sequin, Scott D-18, State Rubber (PBM-7) /1/2017 Taicher, Kevin D-18, State Rubber (PBM-7) 16 8/1/2017 VanDeHei, Jamie State Rubber (PBM-7) /2/2017 Goral, Nick State Rubber (PBM-7) /2/2017 Hennes, Pat Traffic Control for PBM-7 Rubber 12 8/2/2017 Sequin, Scott D-18, ERC Call-in 12 8/2/2017 Thompson, Nick State Rubber (PBM-7) 12 8/3/2017 Dixon, Darrell Signing, ERC Call-in 12 8/7/2017 Goral, Nick D-17 Storm Sewer 12 8/7/2017 Messerschmidt, Bill D-17 Storm Sewer /7/2017 Umentum, Matt D-17 Storm Sewer 13 8/8/2017 Messerschmidt, Bill D-17 Storm Sewer 12 8/8/2017 Umentum, Matt D-17 Storm Sewer /9/2017 Liss, Tim Paintstriping / Centerlining 12 8/9/2017 Maus, Todd Paintstriping / Centerlining /11/2017 Liss, Tim Paintstriping / Centerlining 13 8/11/2017 Maus, Todd Paintstriping / Centerlining 13 8/14/2017 Cisler, Mike HS-9, D-17 - Grading, Tree Down 14 8/14/2017 Dixon, Darrell I-43 Closure, Signing 12 8/14/2017 Gussert, Tim D /14/2017 Ledvina, Jason I-43 Closure, Paintstriping /14/2017 Maus, Todd Paintstriping / Centerlining /15/2017 Cisler, Mike HS-9, D-17 - Grading /15/2017 Goral, Nick D /15/2017 Reedy, Jason D-17 & D /15/2017 Schraufnagel, Dan HS-9, D-17, Tree Down 15 8/15/2017 VandenBush, Ken Signals, Prepare for BC Fairgrounds 12 8/16/2017 Cisler, Mike D /16/2017 Dixon, Darrell Signing, ERC Call-in /16/2017 Melbauer, Charlie D /16/2017 Schraufnagel, Dan D /16/2017 Williams, Tim D /17/2017 Hennes, Pat Signing, ERC Call-in 12 8/23/2017 Corrigan, Chad Seal Bridge Decks - State /23/2017 Dallas, Chris Seal Bridge Decks - State 16 8/23/2017 Dixon, Darrell Signing, Seal Bridge Decks - State /23/2017 Haumschild, Dan Seal Bridge Decks - State /23/2017 Hennes, Pat Signing, Seal Bridge Decks - State 16.5

70 12-Hour Report 8/1-8/31/17 Page 2 8/23/2017 McEwen, Bryan Seal Bridge Decks - State 16 8/23/2017 Oettinger, Tim Sweeping, Seal Bridge Decks - State /23/2017 VanDeHei, Jamie Mowing, Seal Bridge Decks - State /23/2017 Zellner, Aaron Seal Bridge Decks - State /24/2017 Collins, Robbie Paintstriping / Centerlining 14 8/24/2017 Corrigan, Chad Guardrail, Seal Bridge Decks, ERC Call-in /24/2017 Dixon, Darrell Paintstriping / Centerlining 14 8/24/2017 Drewiske, Doug Paintstriping / Centerlining 14 8/24/2017 Ferry, Jim Mechanic Shop / Fuel Truck 13 8/24/2017 Karbon, Dan Paintstriping / Centerlining 14 8/24/2017 Ledvina, Jason Paintstriping / Centerlining 14 8/24/2017 Liss, Tim Paintstriping / Centerlining 14 8/24/2017 Zellner, Aaron Paintstriping / Centerlining 14 8/29/2017 Maus, Todd Paintstriping / Centerlining 12 8/30/2017 Cisler, Mike Grading - Town, County and Landfill 12

71 PUBLIC WORKS FACILITY MANAGEMENT DIVISION 12-HOUR WORK DAYS 8/1/17 thru 8/31/17 DATE EMPLOYEE OPERATION PERFORMED # HOURS WORKED 8/5/17 Liz Schroeder Coverage for a vacant PT position /6/17 Liz Schroeder Coverage for a vacant PT position /20/17 Liz Schroeder Coverage for a vacant PT position 12.0

72 BROWN COUNTY PUBLIC WORKS STAFFING SUMMARY AS OF 8/31/2017 HIGHWAY DIVISION: Position Vacancy Date Reason for Leaving Fill or Hold Filled Date Unfilled Reason Highway Crew 4/27/17 Resigned Fill 8/7/17 N/A Highway Crew 4/28/17 Resigned Fill 8/14/17 N/A Highway Crew 5/4/17 Resigned Fill In Process N/A Highway Crew 6/1/17 Resigned Fill In Process N/A Highway Crew 8/3/17 Resigned Hold (Reclass to Mechanic) N/A N/A Highway Crew 8/4/17 Resigned Fill In Process N/A Budgeted FTE s Actual #FTE s Mgmt / Admin Electrician Engineering Mechanics / Shop Highway Crew Sign Crew Summer * LTE TOTAL FACILITY MANAGEMENT DIVISION: Position Vacancy Date Reason for Leaving Fill or Hold Filled Date Unfilled Reason Facility Worker (0.5) 4/21/17 Resigned Fill 8/14/17 N/A Housekeeper 5/20/17 Transferred Hold per Vacancy Committee --- Hold Budgeted FTE s Actual #FTE s Mgmt / Admin Facility Technicians Facility Mechanics Facility Workers Housekeeping Electrician Summer Help * TOTAL * NOTE: All of the summer students have returned to college numbers reflected in Actual FTE s for both divisions.

73 BROWN COUNTY PUBLIC WORKS DEPARTMENT Winter Highway Maintenance Manual September 25, 2017

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137 BrownCountyPlowingSchedules Schedule1 Midnight7AMSnowStart Snow/BlowingDoneby3PM AM PM AM PM AM Either1AdditionalHourfor8 HoursorEveningCleanup. CrewCGrader/Other CrewA(14Hr) IfCritical CrewB(12Hr) CrewC/GraderCrews(12Hr) CrewA(12Hr) CrewB(8Hr) CrewC(4Hr) 4OvernightCrewC Town(14Hr) Town(12Hr) 4OvernightCrewC CrewC IfStormOngoing> CrewA(14Hr) IfCritical CrewB(12Hr) CrewC/GraderCrews(12Hr) Town(14Hr) Town(14Hr) Schedule2 7AMNoonSnowStart Snow/BlowingDoneby3PM AM PM AM PM AM OvernightCrewC CrewC(4Hr) Either1AdditionalHourfor8 HoursorEveningCleanup. CrewC/GraderCrews(12Hr) <NonOvernightCrew CrewA(12Hr) CrewB(12Hr) CrewA(12Hr) CrewB(8Hr) CrewC(4Hr) 4OvernightCrewC Town(12Hr) Town(12Hr) IfCritical IfStormOngoing> CrewA(14Hr) CrewC/GraderCrews(12Hr) Town(14Hr) CrewB(12Hr) Town(14Hr) Theseschedulesaretemplates(andexamples)thatwewillbeusingforsnowevents.Justaseverystormisunique,thescheduleswillbeadjustedaccordingly. Note: InGeneral: CrewAcanexpecttoworkduringthe3AMto7PMtimerangeduringasnowevent. TownsectionsfollowCrewAtimes. CrewBcanexpecttoworkduringthe7AMto7PMtimerangeduringasnowevent. CrewCcanexpecttoworkduringthe7PMto7AMtimerangeduringasnowevent.CrewCtransitionstonightsandbacktodayswiththesnowevent. GraderCrewsarefillinsforanyopenCrewA,B,orCposition.GraderswillgenerallyfollowtheCrewCscheduleifstaffisavailableandgradersareneeded.

138 BrownCountyPlowingSchedules Schedule3 Noon7PMSnowStart Snow/BlowingDoneby3PM AM PM AM PM AM CrewC(4Hr) <NonOvernightCrew 4Overnight Either1AdditionalHourfor8 HoursorEveningCleanup. CrewA(12Hr) CrewB(12Hr) CrewC/GraderCrews(12Hr) CrewA(12Hr) CrewB(8Hr) CrewC(4Hr) 4OvernightCrewC Town(12Hr) Town(12Hr) IfStormOngoing> CrewC/GraderCrews(12Hr) Town(14Hr) CrewA(14Hr) IfCritical CrewB(12Hr) Town(14Hr) Schedule4 7PMMidnightSnowStart Snow/BlowingDoneby3PM AM PM AM PM AM Overnight Either1AdditionalHourfor8 HoursorEveningCleanup. CrewA(12Hr) CrewB(8Hr) CrewC/GraderCrews(10Hr) CrewC(6Hr) <NonOvernightCrew CrewANormalShift CrewBNormalShift CrewC(4Hr) 4OvernightCrewC Town(12Hr) IfStormOngoing> CrewA(14Hr) IfCritical CrewB(12Hr) CrewC/GraderCrews(12Hr) Town(14Hr) Town(14Hr) Theseschedulesaretemplates(andexamples)thatwewillbeusingforsnowevents.Justaseverystormisunique,thescheduleswillbeadjustedaccordingly. Note: InGeneral: CrewAcanexpecttoworkduringthe3AMto7PMtimerangeduringasnowevent. TownsectionsfollowCrewAtimes. CrewBcanexpecttoworkduringthe7AMto7PMtimerangeduringasnowevent. CrewCcanexpecttoworkduringthe7PMto7AMtimerangeduringasnowevent.CrewCtransitionstonightsandbacktodayswiththesnowevent. GraderCrewsarefillinsforanyopenCrewA,B,orCposition.GraderswillgenerallyfollowtheCrewCscheduleifstaffisavailableandgradersareneeded.

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140 Figure 3.6. Counties Using Anti-Icing BEST PRACTICES Anti-Icing ( ) Douglas Bayfield Iron Ashland Vilas Burnett Washburn Sawyer Florence Price Oneida Forest Polk Saint Croix Pierce Rusk Barron Taylor Chippewa Dunn Eau Claire Clark Pepin Buffalo Trempealeau Jackson Wood Lincoln Marathon Portage Langlade Menominee Shawano Waupaca Marinette Oconto Door Kewaunee Brown Outagamie Anti-Icing Use Heavy Some None Monroe La Crosse Juneau Adams Marquette Waushara Winnebago Manitowoc Calumet Green Lake Fond du LacSheboygan Vernon Columbia Ozaukee Sauk Dodge Richland Washington Crawford Dane Iowa Jefferson Waukesha Milwaukee Grant Racine Lafayette Green Rock Walworth Kenosha 42 // WisDOT Annual Winter Maintenance Report

141 Figure 3.7. Counties Using Closed Loop Ground Speed Controllers BEST PRACTICES Closed-Loop Ground Speed Controllers Douglas Bayfield Iron Ashland Vilas Burnett Washburn Sawyer Florence Price Oneida Forest Polk Saint Croix Pierce Rusk Barron Taylor Chippewa Dunn Eau Claire Clark Pepin Buffalo Trempealeau Jackson Lincoln Langlade Menominee Marathon Shawano Marinette Oconto Door Kewaunee Wood Portage Waupaca Brown Outagamie Monroe La Crosse Juneau Adams Marquette Waushara Winnebago Manitowoc Calumet Green Lake Fond du LacSheboygan Vernon Columbia Ozaukee Sauk Dodge Richland Washington Crawford Ground Speed Controller Status Entire fleet equipped Grant Iowa Lafayette Green Dane Jefferson Waukesha Milwaukee Racine Rock Walworth Kenosha Some trucks equipped No trucks equipped Strong El Niño Brings a Warm Winter // 43

142 Figure 3.8. Counties Using Underbody Plows BEST PRACTICES Underbody Plows Douglas Bayfield Iron Ashland Vilas Burnett Washburn Sawyer Florence Price Oneida Forest Polk Saint Croix Pierce Rusk Barron Taylor Chippewa Dunn Eau Claire Clark Pepin Buffalo Trempealeau Jackson Wood Lincoln Marathon Portage Langlade Menominee Shawano Waupaca Marinette Oconto Door Kewaunee Brown Outagamie Underbody Plow Status Have Do not have Monroe La Crosse Juneau Adams Marquette Waushara Winnebago Manitowoc Calumet Green Lake Fond du LacSheboygan Vernon Columbia Ozaukee Sauk Dodge Richland Washington Crawford Dane Iowa Jefferson Waukesha Milwaukee Grant Racine Lafayette Green Rock Walworth Kenosha 44 // WisDOT Annual Winter Maintenance Report

143 Figure 3.9. Counties Prewetting BEST PRACTICES On-Board Prewetting Douglas Bayfield Iron Ashland Vilas Burnett Washburn Sawyer Florence Price Oneida Forest Polk Saint Croix Pierce Rusk Barron Taylor Chippewa Dunn Eau Claire Clark Pepin Buffalo Trempealeau Jackson Wood Lincoln Marathon Portage Langlade Menominee Shawano Waupaca Marinette Oconto Door Kewaunee Brown Outagamie On-board Prewetting Status Entire fleet equipped Some trucks equipped No trucks equipped Monroe La Crosse Juneau Adams Marquette Waushara Winnebago Manitowoc Calumet Green Lake Fond du LacSheboygan Vernon Columbia Ozaukee Sauk Dodge Richland Washington Crawford Dane Iowa Jefferson Waukesha Milwaukee Grant Racine Lafayette Green Rock Walworth Kenosha Strong El Niño Brings a Warm Winter // 45

144 Figure Counties using Route Optimization BEST PRACTICES Route Optimization Douglas Bayfield Iron Ashland Vilas Burnett Washburn Sawyer Florence Price Oneida Forest Polk Saint Croix Pierce Rusk Barron Taylor Chippewa Dunn Eau Claire Clark Pepin Buffalo Trempealeau Jackson Wood Lincoln Marathon Portage Langlade Menominee Shawano Waupaca Marinette Oconto Door Kewaunee Brown Outagamie Route Optimization Status Underway Planned None La Crosse Vernon Crawford Monroe Grant Richland Juneau Iowa Sauk Lafayette Waushara Manitowoc Winnebago Calumet Adams Marquette Green Lake Fond du LacSheboygan Green Columbia Dane Rock Dodge Jefferson Ozaukee Washington Waukesha Racine Walworth Kenosha Milwaukee 46 // WisDOT Annual Winter Maintenance Report

145 BEST PRACTICES REFERENCE GUIDE II.A.1 Title: Before You Hit the Road Section: Winter Operations Winter Preparation Planning/Guidelines Source: Snow and Ice Control Originator: Ohio DOT Date: October, 95 Page 1 of 2 BEFORE YOU HIT THE ROAD: Make sure you consider the following items: - Know the expected weather forecast - Dress for the conditions - Bring extra clothing - Make sure you have all the necessary safety equipment - Get your route assignment and instructions from your supervisor Check out your truck: - Complete your CDL walk around inspection - Check the condition of your plow and plow shoes. Look for loose bolts, worn shoes and blades and damaged or leaking hydraulic hoses - Check out your tailgate spreader or hopper - Verify all lights and wipers are functioning properly - Check fuel level DURING YOUR SHIFT: - Periodically stop and clean your fights and wipers - Report unusual conditions - Adjust spinner to place salt on middle third of pavement - Periodically, get out and stretch your legs - watch out for obstructions - Pill out M&R 661 DO'S AND DON'T'S OF SNOW AND ICE REMOVAL: DO use Automatic controls DO apply chemicals to the center third of the pavement DO begin applying chemicals to the high side of curves DO check plow blades and plow shoes for wear DO lift your plow when crossing railroad tracks DON T apply chemicals when crossing railroad tracks DON'T forget to treat ramps DON T apply chemicals to shoulders or berm areas DON T apply chemicals to wet or bare pavements unless refreezing is occurring DON T drive at excessive speeds when plowing DON T apply chemical in deep snow

146 DON T plow snow over the sides of bridges Page 2 of 2 AFTER THE STORM: - Empty your remaining salt into the stockpile - Wash your truck - Refuel your truck - Fill out EMS-44 form II.A.1 3/02

147 Wisconsin Transportation Bulletin No. 6 Using Salt and Sand for Winter Road Maintenance To make winter roads passable, maintenance personnel usually must either apply chemical deicers to melt ice and snow or spread sand to provide traction. Since chemicals and sand are costly and may have negative environmental impacts, you need to know how they work. This publication gives you basic information and practical tips on how to use deicing chemicals and sand. Deicing with salt Plowing is the best way to remove snow and slush from pavements. However, clearing winter roads to bare pavement usually requires deicing chemicals. In Wisconsin the most common chemical is salt (sodium chloride), usually mined rock salt that has been crushed, screened, and treated with an anti-caking agent. Rock salt is relatively light about one ton per cubic yard and comes as a mixture ranging from 3 8 granules to fine crystals. Deicing chemicals work by lowering the freezing point of water. A 23.3% concentration of salt water will remain liquid to -6 F. Before a dry deicing chemical can act it must dissolve into a brine solution. It uses moisture from water, snow or slush on the road surface. Changing ice or snow into water also requires heat from the air, the sun, or the pavement. Chemicals only lower the melting temperature; it takes heat to change ice to water. Even when pavement is below freezing, it holds some heat which can help melt snow and ice. Factors affecting deicing action Many factors affect the process of melting snow and ice. Decisions on how and when to apply materials are best left to field supervisors and operators who can assess conditions and adjust to changes. Concentration If too much chemical is used, not all of it will dissolve into solution, and some will be wasted. Too little chemical may not sufficiently lower the solution s freezing point. When salt is dissolved into brine on the road it is near 23% concentration and freezes at -6 F. As snow and ice melt, the extra water dilutes the solution, raising its freezing point. For example, a 10% salt brine solution will stop melting ice and can refreeze at about 20 F, which may require more salt. The ice will not melt or melted snow may refreeze, wasting the chemical. See page 2 for more on spreading rates. Temperature Salt s effectiveness is directly related to the surface temperature of a snow- or icecovered road. As temperatures go down, the amount of deicer needed to melt a given quantity of ice increases significantly. Figure 1 shows that salt can melt five times as much ice at 30 F as at 20 F. Small differences in pavement temperatures have a noticeable effect. Truck mounted temperature sensors give operators information to make better application decisions. Time The longer a deicing chemical has to react, the greater the amount of melting. At temperatures above 20 F both salt and calcium chloride can melt ice in a reasonable time. However, at 10 F it takes an hour for salt to melt 1 8 of ice. Time (minutes) Pounds of ice Figure 1: Amount of ice melted by one pound of salt Temperature F Salt Figure 2: Time to melt 1/8 of ice 3:1 Salt:CaCl Temperature F CaCl 2 1

148 Weather When sun warms the pavement, the heat speeds up melting. Radiant heat may raise pavement temperature 10 F or more above the air temperature. On clear nights, pavements will be colder than the air. Use less chemical when temperatures are rising and more when they are falling. Applying chemicals during blowing snow and cold temperatures will cause drifting snow to stick to the pavement. If chemicals are not used, the dry snow is more likely to blow off the cold road surface. Road surface type Snow and ice may melt more rapidly on a concrete surface because it gives up heat more rapidly. Because asphalt absorbs more solar radiation it may have more heat available for melting snow. This is why snow melts rapidly next to bare asphalt pavement areas. Bridges cool down and warm up faster than road surfaces because air reaches both sides of the deck. This can create varying conditions, such as icing on the bridge deck when the adjacent road is clear. Topography Ice tends to form where topographic conditions, like high banks or dense vegetation, screen the road surface from the sun. The longer the area is shaded, the more likely that ice will form. Since pavement temperatures are lower in shaded areas, you may need more chemicals there. Road cuts may cause snow to drift and blow across the road; the snow will lower pavement temperatures. Traffic effects Traffic aids deicing by spreading and mixing chemicals into the snow and ice. Tire action also breaks up ice layers weakened by salt and can throw slush off the road. Roads with light traffic can be more difficult to maintain because they lack this mixing and breaking action. However, traffic can also trap blowing snow or can melt snow and cause it to refreeze in the wheel tracks, if not treated again. Application width Studies show that snow melts faster when salt is applied in narrow strips. The total amount of snow melted over several hours is the same, however, regardless of application width. If you concentrate spreading (windrowing), you can expose a portion of road surface to the sun quickly. It can then absorb heat and speed up the melting rate. After a road is first plowed, deicing chemicals are usually applied in a windrow 2-4 wide down the middle of a two-lane road. To remove glare ice or keep snow in a plowable condition, you may want to apply chemicals across a broader portion of the roadway. Timing of application Timing is the most important factor in successfully clearing snow by chemical treatment. Early application is critical. Spreading a small amount of chemical deicer when snow is loose and unpacked melts a little snow and turns the rest to slush. Traffic cannot pack down slushy snow which is 15% to 30% water. This lets plows remove it, and plowing is the best way to clear roads. If snow continues to fall, more salt may be needed. Environmental impact A major concern in using chemicals for winter road maintenance is environmental impact. Studies show that soils, vegetation, water, highway facilities, and vehicles are all affected, so it is very important to use these chemicals wisely. Most soil and vegetation impacts occur within 60 of the road and are greatest close to the pavement. Deicing chemicals are highly soluble and will tend to follow any water flow. Salt concentrations in Wisconsin s surface and ground water have increased since the early 60s, the Department of Natural Resources reports, but aquatic life has not yet been affected that we know of. In drinking water sources, which the WDNR also monitors, salt concentrations are within recognized safe limits. In some reported cases, groundwater carrying deicing chemicals has contaminated wells and carried heavy salt concentrations into nearby streams. Deicing chemicals can accelerate deterioration in concrete and steel structures. New construction methods are reducing this impact, but highways and bridges do suffer from chemical damage. Vehicle corrosion is also accelerated. Corrosion on vehicles and structures is estimated to be the largest cost impact of chloride-based chemicals. Even relatively small amounts of chloride will significantly accelerate existing corrosion. Salt storage requirements Localized environmental damage from salt has come largely from stockpile runoff due to the effect high concentrations of salt have on exposed environmental elements. For that reason, it is necessary to prevent stockpile runoff from contaminating ground or surface water by covering the salt and storing it on an impermeable base so rain or melt runoff can t seep in. Wisconsin regulations require highway agencies to store salt inside a covered, waterproof structure. If this is not possible, facilities with stockpiles over 1,000 pounds must be covered with waterproof material, stored on an impermeable pad, and reported to the Wisconsin DOT. Spreading Spreading rates No two storms are alike, so no single set of standards will give the proper spreading rate for all storm conditions. Generally, however, only apply enough chemical deicer to permit plows to remove the snow or to melt glare ice. Experience shows it is most 2

effective to spread 100 to 300 pounds per single lane mile. Do not use any deicer when temperatures are below its effective range. Normally, the lower limit for salt is 15 to 20 F.

149 effective to spread 100 to 300 pounds per single lane mile. Do not use any deicer when temperatures are below its effective range. Normally, the lower limit for salt is 15 to 20 F. If deicing is necessary at lower temperatures, it will take more salt and melting will take much longer (see Figure 2). Alternative chemicals, such as calcium chloride or magnesium chloride, may be a better choice for low pavement temperatures. Other conditions that affect salt application rates: Precipitation type Additional salt is helpful if the snowfall is heavy and the snow is wet, or if freezing rain is expected. Snow accumulation Roads already covered with snow or ice require more salt. Time before next application If it will be 2 hours or more until the next plowing and salting, the section will probably need extra salt. Service level More salt may be justified on a road with heavy traffic requiring a higher service level than on lower volume roads with slower speeds. Melting action spreads across the pavement to lower areas, so concentrate deicers on the center (crown) of two lane roads and on the high side of curves. Chute vs. spreader A spreader with a spinner is the most common way of applying deicers. A spinning circular plate throws the deicer out in a semicircle. Alternatively, a chute applicator can distribute the deicer in a windrow on the road, usually along or near its centerline. Higher truck speeds will cause the salt to roll and spread further across the road. Tests have shown that a chute will do a better job of keeping salt on the road if spreading speed is 25 MPH or greater. Spreaders can be equipped with automatic or ground-oriented controls. These adjust application rates to changing truck speeds, so the driver need not alter the spreader settings. They effectively cut waste and are recommended for spreading straight salt. Spreader calibration It is important to apply the correct amount of salt for the current storm conditions. In order to control application rates, each spreader must be calibrated for each material you intend to use. Different materials will spread at different rates at the same spreader control setting, and individual spreaders, even identical models, can vary widely in how much they spread at the same control setting. Furthermore, spreaders operate in a very hostile environment low temperature, lots of moisture, corrosive chemicals so, they need to be cleaned and checked every year. Alternative chemicals Salt is the most efficient deicing chemical if road temperatures remain above 20 F. Calcium chloride (CaCl 2 ) and magnesium chloride (MgCl 2 ) are common alternatives for use in colder temperatures. Figure 2 shows how effectively CaCl 2 melts ice at low temperatures. Since these alternative chemicals cost up to 10 times more than salt, mixing some dry CaCl 2 or MgCl 2 with dry salt can be an efficient approach. Figure 2 shows the benefits of a mixture of 3 parts salt to one part CaCl 2. These alternative chemicals are effective at road temperatures below 0 F. Dry calcium chloride and magnesium chloride require special handling. They actually give off heat when they dissolve into brine a very beneficial characteristic. They also draw moisture from the air, providing water for the initial brine formation. These unique properties make them a valuable tool during severe conditions. They are usually stored in moisture proof bags until needed. Otherwise their ability to draw moisture can cause the material to cake and form into large chunks. Pre-wetting Pre-wetting salt is becoming common. Wetting provides moisture to make brine. Faster melting action may be expected. In addition, the wet salt will be less likely to bounce or be blown off the road by traffic. Savings in lost or wasted salt of 20%-30% are possible. Common pre-wetting liquids include salt brine, calcium chloride, and magnesium chloride. Some liquid pre-wetting chemicals may contain additives to inhibit corrosion. Applications of 8-10 gallons of liquid per cubic yard of salt are recommended. Some agencies spray the salt as it is loaded into the truck or pre-treat the salt. However, it is most common to use truck-mounted equipment to spray the salt as it leaves the spreader. Savings from losing less salt can more than pay for pre-wetting. However, these benefits only result if the operator actually reduces the application rates. Anti-icing Anti-icing is a pro-active road maintenance strategy that tries to keep the bond between ice and the pavement surface from forming. It involves applying ice control chemicals before or at the very beginning of a storm. 3

150 Using this strategy often reduces the total chemical used and allows a higher level of service to travelers. The strategy most commonly used now is deicing breaking the bond between the ice and pavement. Obviously, this technique is required once the snow or ice covers the pavement. More chemicals are needed to cut through the ice and break the bond than presumably would be needed to prevent the initial formation of the ice to pavement bond. Various ice control chemicals are being used for anti-icing including liquid salt, liquid magnesium chloride, liquid calcium chloride, CMA, and potassium acetate. See Wisconsin Transportation Bulletin No. 22, Pre-wetting and Anti-icing Techniques for Winter Road Maintenance. Abrasives Sand and other abrasives improve vehicle traction on snow- and ice-covered roads. They can be used at all temperatures and are especially valuable when it is too cold for chemical deicers to work. Abrasives are normally used on gravel roads because chemicals will soften the surface and cause plows to scrape off the gravel. Low volume roads commonly receive only abrasives. Sand is the most common abrasive, but slag, cinders, and bottom ash from power plants are also used. Abrasive quality Some sand and abrasives perform better than others. For better traction, use material with crushed or angular particles. Rounded particles are less effective. Very small particles and dirt are actually harmful to traction. Material larger than the #50 sieve is most effective. To minimize windshield damage, use materials in which all particles are less than 3 8 diameter. Abrasive application Abrasives are usually applied only at hazardous locations such as curves, intersections, railroad crossings, and hills at rates of 500 pounds (0.18 cubic yard) to 2 cubic yards per mile. It is important to calibrate spreaders to control application rates. Since abrasives must stay on the surface to be effective, they should not be used when they will be covered with snow or blown off quickly by traffic. Heavy traffic reduces their effectiveness, requiring repeat application. Combining chemicals with sand Treating sand with pounds of salt per cubic yard is necessary to prevent freezing and keep it workable. If slag, cinders or other abrasives are wet they also require salt, in the same amount, to be usable. Pre-wetting sand with a liquid deicing chemical just before spreading has proven effective in embedding the abrasive on icy pavements. Some agencies mix more salt with their abrasive than is needed for freeze-proofing. This practice is often wasteful and ineffective. Blending does not produce a new material. It is still just salt that melts and sand that can aid traction if it stays between the tire and the ice. In a blend, sand and salt often work against each other. IF the goal is for sand to stay on the surface for traction, the salt in the mix either blows off and gets wasted or does its job and melts the snow. However, tires can then push the sand down into the slush, making it ineffective for improving traction. IF the goal is for salt in the blend to melt snow and ice so plows can clear the pavement, then the sand gets removed too, wasting it. In addition, salt melts less ice when mixed with sand. Avoid waste. Use straight salt when it will work best and apply freeze-proofed abrasive when salt is not effective or not needed. Environmental impacts Abrasives used for winter road maintenance have some negative environmental impact. They can clog storm water inlets and sewers. Cleanup may be necessary in urban areas, on bridge decks, and in ditches. The materials may wash downstream and end up in streams and lakes which can have a negative impact on fish habitat. Salt mixed with abrasives to keep them unfrozen and usable has the same potential impacts as described earlier. In particular, salt-treated abrasives can accelerate vehicle corrosion. Documented pollution from particles less than 10 microns (pm 10) has led to concern about the impact of winter abrasive use on air quality. As a result, cleaner abrasives and quicker cleanup after storms are being required in areas with severe air pollution. Abrasive storage requirements Wisconsin regulations require that abrasives treated with salt meet certain storage requirements. All salt-treated abrasives must be covered from April 1 to October 1 each year. If the abrasive has more salt than 5% by weight (approximately 140 pounds per cubic yard), it is considered the same as salt and must be covered at all times and stored on an impermeable base. Salt and abrasive storage facilities holding more than 1,000 pounds must be reported to the Wisconsin DOT which conducts an annual inspection. Revised August 2005 Wisconsin Transportation Information Center. Wisconsin Transportation Bulletin is a series of fact sheets providing information to local town, municipal and county officials on street and highway design, construction, maintenance, and management. These fact sheets are produced and distributed by the Wisconsin Transportation Information Center LTAP, a project of the University of Wisconsin-Madison, Department of Engineering Professional Development, funded by the Federal Highway Administration and the Wisconsin Department of Transportation. UW-Madison provides equal opportunities in employment and programming, including Title IX requirements. Print copies are available free while supplies last from the Transportation Information Center, UW Madison, Department of Engineering Professional Development, 432 North Lake Street, Madison, WI PHONE 800/ FAX 608/ tic@epd.engr.wisc.edu. Download as a PDF from 4

151 Wisconsin Transportation Bulletin No. 22 Pre-wetting and Anti-icing Techniques for Winter Road Maintenance Maintaining safe roads during winter storm conditions requires skill and knowledge. Recent developments in the use of liquid chemicals offer new options to road maintenance agencies beyond what they can do with dry salt and sand. Chemicals other than salt are being used more and more. This publication describes these new options and gives basic information on pre-wetting and anti-icing. Pre-wetting is a strategy of applying a liquid deicing chemical to a dry solid before or during its application to the pavement. When a liquid is applied to a rock salt particle, the particle absorbs a minor amount of the liquid which increases its density. The liquid also encapsulates, softens, and begins dissolving the salt particle. The wet salt stays on the road surface better, bouncing less and resisting traffic action. Pre-wetting salt Pre-wetting salt has been used since the late 60s. It has several advantages: Reduced loss of salt from bounce and scatter. (Savings up to 30%. See Figure 1) Quicker melting. Better salt penetration into ice and snow pack. Melts at a lower temperature if wetted with other deicing chemicals. Any deicing chemical can be used for pre-wetting. Liquid salt, calcium chloride, magnesium chloride, or blends are commonly used. Chemicals with lower eutectic temperatures (lowest temperature at which it can still cause melting) help extend salt effectiveness on lower temperature pavements. Figure 2 shows the difference between dry salt and salt pre-wetted with calcium chloride. Note that the melting effectiveness of both dry and pre-wetted salt decreases as road temperatures drop. Below 10 F there is almost no melting benefit. 100% 75% 50% 25% 0 Volume (ml) Center 1 /3 of 24 ft pavement 46% Dry 78% Outside 2 /3 of 24 ft pavement 24% 18% Not retrieved from pavement 30% 4% Pre-Wet Dry Pre-Wet Dry Pre-Wet Figure 1: Salt retrieved from pavement surface F Dry salt Salt pre-wetted with calcium chloride 20 F 15 F 10 F 5 F Ice temperature Figure 2: Ice melted in 20 minutes Source: Michigan Highway Department Transportation Research Record 1157, p. 43, 88 1

Salt is usually pre-wetted with 8-12 gallons of liquid per ton of salt. Pre-wetting can be done in the stockpile; as spreader trucks are loaded; or by spraying the salt as it is spread on the road.

On-board pre-wetting at the auger shows better coverage than spray at the spinner.

Field research has documented equal or improved performance of 20% less pre-wetted salt compared to dry salt.

152 Salt is usually pre-wetted with 8-12 gallons of liquid per ton of salt. Pre-wetting can be done in the stockpile; as spreader trucks are loaded; or by spraying the salt as it is spread on the road. Pre-wetting at the shop requires less equipment but reduces flexibility of use. Pre-wetting on board the truck allows better coverage and treatment as needed. On-board pre-wetting at the auger shows better coverage than spray at the spinner. Savings are possible if operators reduce application rates when spreading pre-wetted salt to take advantage of its faster action and lower salt loss. Field research has documented equal or improved performance of 20% less pre-wetted salt compared to dry salt. Tanks for pre-wetting liquid: saddle-bags on a hopper spreader LEFT, and at the front of a dump body with a tailgate spreader RIGHT. bridge deck and pavement frost. Specialized equipment is needed to apply small amounts of liquid chemicals. Detailed weather predictions are also helpful. Faster melting action is the main benefit of pre-wetting salt. After 20 minutes the difference is significant. This photo shows two salt particles penetrating ice. The one on the right was pre-wetted. Pre-wetting abrasives Pre-wetting sand and other abrasives is done to hold them on the pavement. Pre-wetting at rates of gallons of liquid chemical per ton of abrasives has proven effective. Agencies report that higher truck spreading speeds are possible with pre-wetted sand. Research on the use of very hot water (heated on-board) for pre-wetting is very promising. Anti-icing Anti-icing is a proactive snow and ice control strategy. A small amount of liquid chemical is applied to pavements and bridge decks before a storm to prevent ice from bonding with the surface. By contrast, the more commonly used strategy is deicing: applying chemical during or after a storm to break the ice/pavement bond so plows can clear the road. Anti-icing is commonly used on pavements where the policy is to provide a high level of service or a bare pavement. It has proven very effective at preventing Benefits of anti-icing An anti-icing strategy can produce significant benefits: Better pavement conditions (improved friction) can be achieved, reducing the number of crashes. (One study in Idaho reported 83% fewer crashes Less chemical is required to prevent ice bonding than to remove ice after it has bonded to the pavement. Anti-icing applications are reported to last for several days, particularly in preventing frost on bridge decks. Clean-up after a storm may be easier with less ice bonded to pavement. Application can be made during regular working hours, reducing some overtime costs. Fixed liquid spray systems at bridges and intersections are possible. A Michigan DOT report covering found that anti-icing can reduce salt, reduce materials costs, and improve safety (Research Report R1418, 2002). Costs and concerns about anti-icing Implementing an anti-icing system involves costs for equipment, weather forecasting services, and training. Concerns about slippery roads and environmental effects must also be addressed. New or better equipment for applying the anti-icing liquid to roads may be needed, including bulk storage tanks, on-board tanks, pumps, and spray applicators. If your weather forecast is poor and a storm does not arrive, you may waste the resources; if the storm hits sooner than expected you may lose the opportunity. Most state DOTs have extensive Road Weather Information Systems (RWIS) that you may be able to tie into. Specialized weather forecast services are available that 2

provide improved storm timing and pavement temperature forecasts. Radar and additional forecast information from the National Weather Service is available through the Internet.

153 provide improved storm timing and pavement temperature forecasts. Radar and additional forecast information from the National Weather Service is available through the Internet. The low tech approach is to call the agency that is up-storm from you and ask what s happening. Changing to any new system requires training. Fortunately, anti-icing has been in use quite a while now and many resources are available including manuals, online newsletters, and national and local workshops. Also, you can learn to use new equipment by practicing application and by taking advantage of vendor training. When a crash occurs before the storm hits and the road has been sprayed, fingers quickly point at the liquid chemicals. This isn t common, and many of the crashes blamed on anti-icing turn out to be situations where dilution and refreeze occurred, or even that the road wasn t slippery at all. Some conditions, especially in early winter, do produce slipperiness; agencies using anti-icing learn to recognize and accommodate for them. Of course everything that goes on the road is in the environment, so it is important to be careful what and how much you use whether it is traditional salt and sand or corrosive chemicals. If you implement antiicing properly, you will use fewer chemicals than with deicing, and less abrasive material. This makes it anti-icing environmentally beneficial. Guidelines for anti-icing The Wisconsin Department of Transportation offers the following anti-icing guidelines to counties, which maintain all state highways. When to anti-ice Anti-icing should be the first in a series of strategies considered for each winter storm. Anti-icing should be conducted prior to forecasted frost, freezing fog, or black ice events on bridge decks and pavement trouble spots as a minimum, assuming conditions in this guideline for anti-icing are met. Other areas (hills, curves, shaded areas, ramps, or intersections) may be treated as determined by the county, on an as-needed basis. Treatment for frost or black ice incidents can be made on a regular schedule; twice per week during the typical frost season (beginning and end of the winter months), or in accordance with weather forecast information. Applications in anticipation of a possible frost incident or snow event on a Saturday or Sunday may be made on the preceding Friday. Typically anti-icing is a light application to dry pavement from streamer nozzles hours before a predicted frost or snow event. Anti-icing should be done during normal, low traffic volume, non-overtime work hours. In the case of a county with normal overnight working hours, antiicing could be done at night or other off peak traffic times. In counties where split shifts are not used, antiicing should be done so as to minimize disruption to the traveling public. Applications should normally be made hours prior to a predicted frost or snow event depending on the material used. Some anti-icing agents will last longer than others. When traffic volumes are high, use of a following vehicle for traffic control may be necessary. Due to high traffic volumes, additional application may be required if the anti-icing agent residue is worn off the bridge deck or pavement surface. Anti-icing may also be conducted prior to predicted light sleet and light (less than 0.5 /hr) or moderate ( /hr) snow events. If precipitation persists, additional anti-icing applications may be necessary to prevent refreeze due to dilution of the chemical or switching to deicing applications may be necessary. Anti-icing should be conducted when the pavement temperature is at or above 23 F or the pavement temperatures are forecast to rise or stay above 23 F. Liquid agents are the preferred material for anti-icing treatments. Although applying pre-wetted salt prior to an event can technically be considered anti-icing, liquid agents work more effectively than solids and there is also less waste with liquid applications. 3

154 When not to anti-ice Liquid anti-icing should not be conducted: Prior to forecast of rain or freezing rain events. When winds are more than 15 MPH. When the anti-icing agents have the potential of causing snow to stick to the roadway under blowing and/or drifting snow conditions. When the pavement temperature is below 20 F or forecast to fall below 20 F. After the bond between the snow and the pavement has already occurred. Liquid should never be applied onto an icy or snow-packed surface. Use discretion in applying anti-icing agents before heavy (over 1 inch per hour) snowfall events, due to limited experience. It may become a more viable option with greater experience. Precautions Calibration Liquid anti-icing application equipment should be calibrated at the beginning of every winter season. Application equipment that has been transferred to another truck, modified, or repaired should be recalibrated. Equipment should be monitored during use and recalibrated when performance appears questionable. Drifting To minimize drifting of liquid anti-icing agents drip or pencil spray type nozzle heads are preferred over fan type nozzle heads. When truck speeds will exceed MPH, consider adding drop rubber tubing extensions to drip or pencil spray nozzle heads to reach the surface. Persistence If not diluted by rain or snow, residues of liquid anti-icing agents can remain on the surface for up to four days after application. When rain, snow, or moisture in the air dilutes the residual anti-icing agent on the surface, refreezing can occur. Reapplication may be needed. Slipperiness Reduce application rates after dry spells, especially when pavement temperatures are warm (45-50 F), when humidity is 45%-55%. Bridge decks and pavement surfaces where residues of oil products and/or rubber have built up may become slick when sprayed with an anti-icing liquid. The guidelines above and on page 3 were excerpted from the Wisconsin Department of Transportation, State Highway Maintenance Manual, Guideline 32:35, October 1, Using liquid chemicals Winter maintenance liquids are solutions of water with one or more chemicals such as road salt (sodium chloride, NaCl), calcium chloride (CaCl 2 ), or magnesium chloride (MgCl 2 ). Ordering, handling and applying liquid chemicals requires special knowledge. However, their action on the roadway is similar to solid deicing chemicals since solid chemicals must first be dissolved into solution before they can begin their melting action Advantages of using liquid chemicals include: They are already in solution; their melting action is nearly instantaneous. They can be used to both pre-wet solid chemicals and anti-ice pavements. Liquid salt (NaCl) can be made at local highway shops and cost is low (5 cents/gal). They can be applied at lower rates than solids and adhere better to the pavement. Vendors offer corrosion inhibiter additives. Disadvantages of using liquid chemicals are: They will become diluted (and may refreeze) more quickly than solid salt during heavy snow or ice storms. Transporting chemicals that are mostly water (68%-78%) can be costly. They cannot be used for anti-icing when freezing rain, glare ice, or snow pack conditions exist. Their anti-icing use is generally limited to pavement temperatures above 20 F. They require special equipment for liquid storage, pumping, and application. Application Application rates in the range of gallons per lane mile are being used. This is equivalent to 60 to 120 pounds per lane mile of dry chemical. Even smaller applications of 15 gallons per lane mile have been reported effective in anti-icing for frost. The actual liquid chemical application will depend on the choice of chemical, air and pavement temperatures, and storm conditions. Figure 3 gives a comparison of equivalent application rates for calcium chloride and Temperature Salt Calcium Chloride Magnesium Chloride Degrees F Solid Liquid Solid Liquid Solid Liquid lb/lane mile gal/lane mile lb/lane mile gal/lane mile lb/lane mile gal/lane mile Figure 3: Equivalent application rates Source: Snow Removal and Ice Control Technology, Transportation Research Circular E-C063, page 48. 4

Often anti-icing programs start small with tanks on the back of a patrol truck LEFT. A large tanker RIGHT is more efficient for anti-icing a larger road system. magnesium chloride to salt.

Streamer nozzles ( 1 8 to 3 8 ) are preferred to fan spray nozzles. Applications can be made at 25 MPH to 55 MPH.

They are necessary to ensure that you gain the full cost savings of the anti-icing strategy.

155 Often anti-icing programs start small with tanks on the back of a patrol truck LEFT. A large tanker RIGHT is more efficient for anti-icing a larger road system. magnesium chloride to salt. At lower road temperatures the application rates for calcium chloride and magnesium chloride become less compared to salt. Special spreading equipment is required for low volume liquid applications. Streamer nozzles ( 1 8 to 3 8 ) are preferred to fan spray nozzles. Applications can be made at 25 MPH to 55 MPH. Equipment that allows applications in more than one lane and ground-oriented (computer-controlled) equipment are useful. They are necessary to ensure that you gain the full cost savings of the anti-icing strategy. Phase diagrams The lowest point at which a specific chemical suppresses freezing depends on temperature and concentration. Figure 4 helps illustrate this. This diagram shows the temperature at which various concentrations stop thawing or change phase for salt. Temperature 32 F 20 F 0 Solution + Ice ICE + SALT Salt solution Solution + Salt -20 F 0% 10% 20% 30% 40% Figure 4: Phase diagram of salt. Solution concentration (% by weight) Spray bar with hose extensions on nozzles, shown here tied up for transport. During application hoses drag on road. Concentration and freezing point Like salt and other solid chemicals, liquids work by depressing the freezing point on the pavement. Choosing which specific chemical or blend of chemicals to use depends on the characteristics of the chemical, temperature and weather conditions, available moisture, and cost. In order to make this choice, you need to understand the characteristics of each chemical. At 20 F, salt will melt ice at an 11% solution. At 10 F, it must be at 18% solution. The freezing point continues to decrease with higher concentrations until the maximum freezing point, or eutectic point is reached. Salt brine stops working at about -6 F and 23% concentration (23% salt, 77% water by weight). At 23% solution there is lbs of salt per gallon. The total weighs about 10.6 lbs per gallon. Notice that at higher concentrations (25%), the freezing point of the liquid chemical increases sharply. It is important to understand the concept of phase change in order to use liquid chemicals effectively and 5

156 avoid waste. The curved lines on the diagram separate the phases of the solution: Above the curve all liquid solution; melting action. Below the curve mixture of solution and ice or salt; refreezing action. Below the eutectic point solid ice. Thus, the diagram describes the freezing point of salt brine as a function of the solution s concentration. Note particularly that the freezing point of the brine solution is lowered (has more melting capability) as the concentration increases, until the eutectic point is reached. Beyond the eutectic point the freezing point will increase (has less melting capability) as the concentration increases. In snow and ice control operations, and particularly during anti-icing treatments, it is important to know what chemical concentrations you are applying. In addition, it is important to monitor the pavement conditions after it is applied to watch for conditions where refreezing may occur. Refreezing The phase diagram shows how deicing and refreezing can occur on a pavement. When a liquid chemical is applied, snow or ice on the pavement will melt as long as the temperature on the roadway is above the freezing temperature for the concentration of the chemical. As ice is melted the water combines with the solution already on the pavement, causing dilution. Dilution lowers the concentration, meaning that the freezing point goes up. Melting and dilution continue until either all of the ice is melted or the solution is too diluted to work. Snow, rain or freezing rain after application will also cause dilution. Refreezing will occur if the chemical concentration is not adequate to produce melting at the actual pavement temperatures. For snow and ice control: Adjust initial application rates depending on both pavement temperature and the amount of snow and ice on the road. Monitor the dilution process by tracking pavement temperature, melting, and additional precipitation. If solution concentration on the pavement decreases into the pavement s freezing temperature range before the pavement is clear, refreeze will take place. Additional applications, a different chemical or blend of chemicals, or other winter maintenance treatment will be needed. Temperature Cost and quality control Liquid salt is the least expensive product but it has the normal temperature use limitations. Liquid calcium chloride, magnesium chloride and potassium acetate with corrosion inhibiting additives are significantly more expensive but can be used at lower temperatures. Figure 5 shows the phase diagrams for commonly used chemicals. When purchasing liquid chemicals or producing your own liquid chemicals from dry products, be aware of the percentage solution that is being delivered. Liquid magnesium chloride products may vary between 23% and 30%. At 30% solution there is 2.36 lbs of magnesium chloride per gallon, weighing 10.7 lbs per gallon total. Higher chemical concentrations allow vendors to ship more material at less cost. The cost effectiveness of liquid chemicals must also take into account the percentage concentration to determine the best value. Liquid chemicals usually contain some degree of impurities. They are not directly a concern for effectiveness, but they can settle out and clog nozzles and pumps. Different chemicals settle or coagulate at different temperatures. In addition, the viscosity of a chemical changes with temperature. At very low temperatures the chemical may not freeze, but may become too thick for pumps and applicators to work. 60 F 40 F 20 F 0-20 F -40 F -60 F -80 F Magnesium chloride Salt Calcium chloride Potassium acetate 0% 10% 20% 30% 40% 50% Solution concentration (% by weight) Figure 5: Phase diagrams of four chemical solutions 6

Quality control is important when purchasing and using liquid chemicals. Hydrometers can be used to field check the specific gravity of the chemical.

Storage and handling procedures for liquid chemicals must comply with state regulations. Tanks must be designed to handle liquids heavier than water. Agitation or recirculation may be necessary.

157 Quality control is important when purchasing and using liquid chemicals. Hydrometers can be used to field check the specific gravity of the chemical. Readings must be adjusted for the actual temperature of the liquid. This test will determine if the delivered chemical is in the allowable range of concentration. Storage and handling procedures for liquid chemicals must comply with state regulations. Tanks must be designed to handle liquids heavier than water. Agitation or recirculation may be necessary. Check for storage and pumping recommendations from your supplier. Preparations and precautions Before you send out the anti-icing equipment, let the public know about it. Include it in pre-storm announcements along with other reminders about driving near winter equipment. Signs on the back of trucks are also helpful. Use the most accurate weather predictions you can get to avoid applying chemicals when no storm occurs. Low temperatures, below 20 F, strong winds, and heavy snowfall or freezing rain conditions all make anti-icing problematic or ineffective. Slippery pavements may develop with anti-icing due to refreezing or to chemical slipperiness. Refreezing can occur if the chemical is diluted, temperatures drop, or blowing snow is trapped. Warm temperatures and high humidity can dilute chemicals with calcium or magnesium because of their high attraction for moisture. Pavements wet with deicing chemicals have slightly less friction than pavements wet with water. Some chemicals also go through a slurry stage when they either dry out and return to a solid state or then hydrate and go from solid to liquid state. This slurry stage is very temporary but causes an additional drop in friction (15%) on the pavement. This so-called chemical slipperiness is not usually enough by itself to cause loss-ofcontrol problems for highway traffic. However, when pavement temperatures are warm (45-50 F ) and dirt and oil come to the surface of the pavement, slippery conditions may develop for a short time, leading to claims of chemical slipperiness. Very few cases of slipperiness have been reported where salt brine was used. Follow-up Winter storms are notoriously variable. The treatment used early in a storm may have to be modified as it proceeds, especially if light snowfall is interspersed with periods of heavy snowfall. Continue monitoring weather conditions to determine your actions. Consider snow buildup on road edges, time of day or night, temperature trends, traffic volumes and when rush hour may begin, and predictions from weather services. Re-application may be needed or you may transition into plowing and normal deicing. Snow pack may still develop and a bond may form between the pack and pavement even when anti-icing was successful. Usually the bond will not be as strong. After the storm, when operations are normal, take time to review the anti-icing operation. You may identify potential improvements in operations or equipment. Involve all levels of maintenance personnel from district level supervisors to equipment operators. Many times a supervisor and an operator will see different things during a storm and both perspectives are useful. Consider how you measure effectiveness or success in your winter maintenance operation, and review costs and results for both traditional plowing/deicing and anti-icing strategies. When learning to use liquid chemicals, evaluation of field performance is critical. Some agencies have found a TAPER form useful in this evaluation. It provides an organized way to collect data on conditions and materials applied. The key is to collect actual roadway performance information which allows your agency to develop its own future guidelines. TAPER stands for Temperature, Application, Product, Event, Results. Sample TAPER forms are available from the TIC Web site publications page, Summary Pre-wetting and anti-icing practices are a means for maintaining roads in the best condition possible during a winter storm. They are also a way to do so efficiently. However, do not assume that they will automatically result in reduced overall costs. Use operator training, sprayer calibration, ground oriented spreader controls, pavement temperature sensors, and accurate weather information to keep liquid chemical use at the lowest effective amount. Review and evaluate your operations and keep up to date with improvements. 7

158 References Anti-icing Technique, Guideline 32.35, State Highway Maintenance Manual, Wisconsin Department of Transportation, Bureau of Highway Operations, October 1, Anti-Icing Techniques for Winter Maintenance, December 2002, The Road Ahead, Virginia Transportation Technology Transfer Center. Agricultural By-products for Anti-Icing and Deicing Use in Michigan, December 2002, Michigan Department of Transportation, Research Report R1418. Field Trials of Pre-wetted Salt and Sand with MgCl 2 and CaCl 2 Brines: Efficiency and Effects, September 94, Province of British Columbia, Ministry of Transportation and Highways, Project No Manual of Practice for an Effective Anti-icing Program: A Guide for Highway Winter Maintenance Personnel, June 96, Federal Highway Administration. FHWA-RD Salt Management Guide, December 99, Transportation Association of Canada. Snow Removal and Ice Control Technology, Sixth International Symposium on Snow Removal and Ice Control Technology, June 7 9, 2004, Transportation Research Circular E-C063, Transportation Research Board, Washington, DC 20001, December 2005 Wisconsin Transportation Information Center. Wisconsin Transportation Bulletin is a series of fact sheets providing information to local town, municipal and county officials on street and highway design, construction, maintenance, and management. These fact sheets are produced and distributed by the Wisconsin Transportation Information Center LTAP, a project of the University of Wisconsin-Madison, Department of Engineering Professional Development, funded by the Federal Highway Administration and the Wisconsin Department of Transportation. UW-Madison provides equal opportunities in employment and programming, including Title IX requirements. Print copies are available free while supplies last from the Transportation Information Center, UW Madison, Department of Engineering Professional Development, 432 North Lake Street, Madison, WI PHONE 800/ FAX 608/ tic@epd.engr.wisc.edu. Download as a PDF from 8

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186 BEST PRACTICES REFERENCE GUIDE II.L.2 Title: Application of Snow and Ice Chemicals Section: Winter Operations Snow Plowing Source: Snow and Ice Control Originator: Duane E. Amsler, Cornel Local Roads Program, New York State Date: 96 Page 1 of 2 Snow Plowing and Removal Removal of accumulations of snow from highways and other transportation facilities by plowing is usually the first step in restoring friction. However, if the anti-icing strategy was successfully employed, it may be the last step. Snow Plowing Procedures Snowplow operators use a variety of techniques that depend on highway configuration and environmental conditions. There are some general guidelines that apply: Fresh snow is easier to plow than consolidated snow. Try not to leave berms of snow on the traveled way for long periods of time. Maximize the use of right turns in routing. Where possible, cast snow downwind. Do not plow recently applied ice control chemicals off the road. Do not plow snow off bridges and overpasses except where no traffic passes beneath. Use close echelon plowing (where the plows are close enough together that traffic cannot pass) to the extent possible on one-way (divided) highways. Minimize backing maneuvers. Plow snow well beyond the high point on banked curves and other similar sections. Do not cast snow into traffic. Try to plow before peak traffic. When visibility is reduced to near zero by falling or blowing snow, get the plow vehicle safely well off the road and shut all lights off. Resume operations when visibility improves to a reasonably safe distance. Benching and Shelving Benching and shelving are usually accomplished with wing plows. It may be part of a pushingback operation to provide additional snow storage, improve sight distance, or widen an existing plowed path. Here, the wing plow is near horizontal and several feet off the ground. This operation usually requires placing locking pins in the wing plow push arms. These pins must be removed when performing normal plowing operations.

187 Page 2 of 2 Snow Removal Snow removal operations usually require significant relocation of snow as opposed to simple displacement provided by plowing. Snow blowers and large wheel loaders are the primary pieces of equipment used for this purpose. Snow blowers can cast snow well away from the working location or deposit it into a truck for subsequent disposal. In the highway environment, try to cast snow downwind. This will minimize the snow cloud and make the operation more visible to motorists. If it is calm, cast the snow into the direction of the prevailing wind. The resulting snow berm will act like snow fence and capture some blowing snow that would otherwise reach the highway. When using snow blowers, care must be exercised to avoid involvement with non-snow objects. Large loaders can also relocate snow into trucks or elsewhere in the immediate area. This is a slower operation, but it works. Safety Restoration and Clean-up Operations After snowplowing and the return of the pavement surface to the appropriate level of service, safety restoration and clean-up operations should commence. In general, safety-related tasks should precede mobility and commerce related tasks. The following list of clean-up operations is in approximate priority order: 1. Snow removal at locations that could melt and run onto the pavement (banked curves, superelevated ramps, etc.). 2. Snow removal on bridges (melt water concerns). Do not cast snow on features below. 3. Snow removal in areas of reduced sight distance (intersections, curves, interchanges, etc.). 4. Snow removal at "high probability locations" around safety features (impact attenuators, guiderail, close median barriers, etc.). 5. Removal of accumulated snow that may be causing traffic to use other than intended pavement areas. 6. Snow removal in limited storage areas (narrow median, shoulders, gores, etc.). 7. Snow removal from recessed drainage features, culverts, channels, gutters, sag curves, etc., that may cause melt water to flow onto the pavement and freeze at night. 8. Snow removal from shallow cuts that may have drifted in. 9. Snow and ice removal at railroad crossings. 10. Snow removal on raised islands, medians, shoulders, gores, bridge sidewalks and guiderail support. Also rumble strips, curbs, raised pavement markings, buried delineator posts, etc. 11. Snow removal from buried or obscure signs. 12. Snow removal in restricted areas that may impact mobility. 13. Snow removal in business/commercial areas. II.L.2 3/02

188 BEST PRACTICES REFERENCE GUIDE II.L.3 Title: Removal of Snow from Special Areas Section: Winter Operations Snow Plowing Source: Highway Maintenance Guidelines Originator: New York State DOT Date: December, 93 Page 1 of 3 Removal of Snow from Special Areas A. General After the storm is over, the shoulders, crossovers and gore areas have been plowed, and benching and pushing back operations are underway or complete, the removal of snow from special areas should commence. These operations require loading equipment and hauling vehicles. Front end loaders, snowblowers and heavy dump trucks are usually used f or this purpose. If necessary, rental equipment should be considered. This may be available under a Municipal contract or through private rental. B. Bridges When possible, accumulated. snow should be removed from locations that could melt during the day, drain across the deck, and freeze at night. Bridge drainage features should be cleared to facilitate the designed discharge of water. Also, bridges having features to prevent plowed snow from leaving the bridge should have the accumulated snow removed to make room for the next storm. C. Impact Attenuators When possible, accumulated snow should be removed from areas that could effect the performance - of impact attenuators. D. Banked Curves When possible, accumulated snow on the high side of banked curves should be removed to minimize the risk of melt water freezing on the pavement. E. Sags (Vertical Curves) When possible, drainage channels should be created in the snowbanks on both sides of the highway at the low point in sag vertical curves to minimize the risk of melt water accumulating on the pavement. F. Ditches and Culverts When possible ditches and culverts having a history of snow melt-water runoff problems should be cleared of accumulated snow prior to anticipated thawing weather.

189 Page 2 of 3 G. Closed Drainage Systems The inlets to closed (underground) drainage systems should be cleared prior to anticipated thawing weather. H. Narrow Median Areas Accumulated snow should be removed from narrow median areas if it poses possible melt water problems or otherwise interferes with the traffic control function of the medians. I. Guardrail and Median Barrier Snow should be removed as close to guardrail and median barrier as reasonably possible with plow equipment. The complete removal of snow from the traffic side of guid6rail and median barrier is not possible with available resources. Snow Removal from Municipal/Commercial Areas Within Municipal and commercial areas, "reasonable passage and movement" may require loading and hauling snow. This work is to be done only to the extent necessary. Need will be determined by the Regional Highway Maintenance Engineer. State forces shall be used to the extent necessary and available. Any combination of State, County, Town and Village forces that is most practicable and applicable under current policy and contract agreements should be used. The clearing of Municipal sidewalks is not intended to be performed or paid for by the State. Prior to disposing of snow removed from municipal/commercial areas, a check of local rules and ordinances relative to snow disposal should be made for reasonable cooperation. Additionally, a check should be made for applicable watershed rules and regulations made or approved by the New York State Department of Health (P.H.L. 1100) for required compliance purposes. Snow Control During Blizzard and White-out Conditions Some snow and wind events produce snowfall intensity that severely limits the visibility and performance factors of the plow operator(s). Temporarily curtailing operations under these conditions may be prudent to preserve the safety of plow operators) and other vehicles using or stranded on the highway and pedestrians that may be in the vicinity of the highway. Most of these events are associated with localized squalls of lake effect snow and are usually of relatively short duration. During these conditions, operators may drive their trucks to a safe location, well off the highway, turn all exterior lights off and contact a supervisor for further direction. Some intense low visibility snowfall/wind events (blizzards) are more sustained and can last from several hours to several days. During these events the overall level of service may be limited to that necessary for supporting local emergency situation response. During this pullback phase, operators waiting for further direction should make appropriate II.L.3

190 Page 3 of 3 preparations and equipment should be made ready for intense operations when the visibility and/or other difficult conditions improve. Generally, this pullback option should only be used in conjunction with declared states of emergency when non-essential highway travel is prohibited. II.L.3

191 BEST PRACTICES REFERENCE GUIDE II.L.4 Title: Maximum Speeds for Safe Plowing Section: Winter Operations Snow Plowing Source: Guideline for Liquid Chemical Application for Snow and Ice Control Originator: Illinois DOT Date: September, 98 Page 1 of 1 Truck speed for plowing snow or spreading salt should be governed by the type of highway, traffic conditions, and pavement conditions. The following speeds are maximums that should be decreased to a safe operating speed when poor conditions are encountered: Maximum 1. Shoulders (earth, gravel, or narrow) 20 Miles per hour 2. Two-lane pavements and shoulder (paved full width) 25 Miles per hour 3. Four-lane (individual pavements) 30 Miles per hour 4. Plows mounted, but raised and not in use 45 Miles per hour 5. Anti-icing 50 Miles per hour

192 BEST PRACTICES REFERENCE GUIDE II.L.5 Title: Snow and Ice Control at Railroad Crossings Section: Winter Operations Snow Plowing Source: Highway Maintenance Guidelines Originator: North Dakota DOT Date: Unknown Page 1 of 1 Snow and Ice Control at Railroad Crossings Special attention should be given to all at-grade railroad crossings during and after snow and ice control operations. Personnel should take care to prevent *now or slush from being carried onto the track5. It may become packed in the rail flanges and create an obstruction that could derail a train or cause a malfunction of signals. If necessary, hand tools can be used to remove all ice and compacted snow at the rail flanges during plowing operations, Sand or chemical deicer should not be dropped on a crossing. The blade of a snowplow should be raised enough to clear the rails. After snow plowing operations have been completed, and during the cleanup operations, all railroad crossings should be inspected to he sure that no visible obstruction to rail traffic exists. If there is such an obstruction, it should be immediately removed if possible. If the obstruction cannot be removed, personnel should contact their District office or Railroad as soon as is feasible. A list of railroad contact persons is included in Appendix A. Personnel may plate red flags to warn the railroad engineer of the obstruction. Such flags mandate that the train stop as soon as possible and not resume, travel until the flag is removed or written permission is received.

193 HANDBOOK Manual Number Minnesota Snow and Ice Control Field Handbook for Snowplow Operators University of Minnesota Center for Transportation Studies Minnesota Department of Transportation Minnesota Local Road Research Board

194 Minnesota Snow and Ice Control Field Handbook for Snowplow Operators August 2005 Published By Minnesota Local Road Research Board (LRRB) Web: Mn/DOT Office of Maintenance Mn/DOT Research Services Section MS 330, 395 John Ireland Blvd. St. Paul, Minnesota Phone: Fax: The University of Minnesota is an equal opportunity educator and employer. This publication is available in alternative formats upon request. This document represents the authors summary of practice and does not necessarily represent the views or policy of Mn/DOT or the LRRB. This report does not constitute a standard, specification, or regulation. Printed with 20 percent postconsumer waste.

195 Acknowledgments This field handbook is dedicated to the plow operators who keep our roads safe all winter long. It is based on the Manual of Practice for an Effective Anti-icing Program, produced by the Utah LTAP Center. Thanks to the following sponsors and participants for their valuable input in the production of this document. Funding Sponsors: Minnesota Local Road Research Board (LRRB) Minnesota Department of Transportation (Mn/DOT) Circuit Training and Assistance Program (CTAP), Minnesota Local Technical Assistance Program (MN LTAP), Center for Transportation Studies (CTS), University of Minnesota Technical Advisory Panel: A Technical Advisory Panel was convened to provide input and review drafts of this handbook. Technical and project leaders: Wendy Frederickson, Mn/DOT Statewide Winter Maintenance Coordinator Jim Grothaus, MN LTAP Kathleen Schaefer, CTAP Committee members: Tom Broadbent, Envirotech Services, Inc. Jeff Dubay, City of Minnetonka Bernie Fasnacht, City of Mankato Greg Felt, Scott County James Klessig, Mn/DOT Central Office Dave Redig, Mn/DOT District 6, Rochester Tim Sheehy, Mn/DOT District 1, Virginia Brian Wolfgram, Mn/DOT District 6, Rochester Other Contributors: Bob Vasek, Mn/DOT Central Office Production: Minnesota Local Technical Assistance Program, Center for Transportation Studies (CTS), University of Minnesota Writing: Connie Fortin and Carolyn Dindorf, Fortin Consulting, Inc. Editing: Pamela J. Snopl, CTS Graphic Design: Cadie Wright, CTS

196 Contents Basic Concepts... 1 Before the Winter... 3 Before the Storm... 5 During the Storm... 9 After the Storm Application Rate Guidelines Materials and Quality Control... Bibliography and Additional Resources Appendix... A-1

197 List of Tables and Figures *Fine-tuning your program *Pounds of Ice Melted Per Pound of Salt *Anti-icing Application Rate Guidelines *Deicing Application Rate Guidelines *Chemical Melting Temperatures... *Material Conversions *Salt Moisture Worksheet *Example Daily Salt/Sand Use Ticket... A-2 *Example Loader Ticket: Daily Salt/Sand Issued... A-3 *Example Documentation Form For Anti-Icing... A-4 *Bare Lanes Data Collection Sheet... A-5 *Duplicates are provided in the pocket of this handbook for ease of use and photocopying.

198 Purpose of this Handbook The purpose of this field handbook is to help promote the understanding of the tools, best practices, and limitations for snow and ice control. The handbook will also help you understand when to use and when not to use these tools and practices. In addition, it encourages progressive changes in snow and ice control practices that will help you reduce salt/sand use and environmental impacts while meeting the safety and mobility needs of roadway users. Less material on roads means less material in lakes and streams. Improved practices such as anti-icing, prewetting, and pretreating are emphasized in this field handbook. Also included are standard best practices expected in a quality snow and ice control program. Throughout the field handbook you will find environmental tips shown with this fish symbol. These tips are provided to help you reduce environmental impacts from snow and ice control operations. A blanket approach will not work for the broad range of conditions Minnesota experiences; different strategies are needed for different regions and different conditions. We encourage you to continue to test, document, and refine the practices from this field handbook.

199 Basic Concepts WEATHER Knowing existing and potential weather conditions is very important for a successful snow and ice control operation. Six pieces of information are especially valuable: 1. Start of precipitation 2. Type of precipitation 3. Total precipitation expected 4. Expected event length 5. Wind conditions (speed, gusts, directions) 6. Temperature trend Monitor the weather closely so that you are available and prepared to act early in storm situations. Weather information sources Phone 511 to get road condition and travel information or visit the Web: Talk to neighboring agencies and share information on conditions. Subscribe to a value-added meteorological service (VAMS). These are useful for viewing weather forecasts. Check the National Weather Service. Check all available weather sources. PAVEMENT TEMPERATURE Most weather stations measure temperature and other conditions 30 feet above ground, which means these conditions can differ substantially from pavement temperatures. Thus, use the pavement temperature not the air temperature to determine your application rate. You ll notice changes in pavement temperature first on bridge decks; pavement temperatures will also be lower in shady areas. Measuring with sensors or RWIS There are two ways to measure pavement temperatures: with sensors or with the Road Weather Information System (RWIS). 1 Pavement temperatures can be substantially lower or higher than air temperatures. Basic Concepts Before the Winter Before the Storm During the Storm After the Storm Application Rate Guidelines Materials and Quality Control Bibliography and Additional Resources Appendix

200 Basic Concepts Sensors can be hand-held or truck-mounted. Hand-held infrared laser sensors are pointed at the pavement to get a pavement or surface temperature while your vehicle is stopped or moving slowly. Truck-mounted temperature sensors measure pavement or surface temperatures while your truck is moving. Ideally, every agency should own at least one truck-mounted unit. RWIS is an Internet service provided by Mn/DOT and available to everyone. The RWIS is a predictive system that consists of a network of towers and temperature sensors embedded in state highways. If you do not have road sensors in your truck, look up the road temperature from the closest state highway on RWIS. This will give you an idea of the local road temperatures. DILUTION: THE CAUSE OF REFREEZE An ice control product will work until product dilution causes the freeze point of the brine to equal the pavement temperature. At this point, the material will stop melting and you may experience refreeze if pavement temperatures are dropping. This process is Dilution of Solution. How long an application will last depends on five factors: pavement temperature, application rate, precipitation, beginning concentration, and chemical type. These factors explain why one application rate will not fit all storm events. 2

201 Before the Winter Take some time before the season to plan your routes and learn the plowing policies. A little planning up-front can help you do a more efficient job in keeping the roads safe. POLICIES Make sure you have a plowing policy and meet to discuss it. Your level of service may be based on average daily traffic, environmental concerns, safety, mobility, economics, and other factors. Inform your citizens of policies. Learn to record what and how much you apply on each shift. Be prepared to analyze and make adjustments to your process based on what you learn. PLAN YOUR ROUTES During the fall, inspect and make sure ditches, culverts, and surfaces are free from obstructions and ready for the spring melt. Remove potential snow traps, such as tall grasses, that will catch and accumulate snow. Drive the assigned routes prior to winter to identify critical areas and find the most efficient way to cover the routes. Inventory all the areas prone to drifting and have a plan to manage them. Know your routes. Plan which way you will start. Be flexible. Conditions could change the way you plow your route. Using less salt doesn t have to reduce safety, but it does protect our lakes. Basic Concepts Before the Winter Before the Storm During the Storm After the Storm Application Rate Guidelines Materials and Quality Control Bibliography and Additional Resources 3 Appendix

202 Before the Winter All good programs include calibration. If you don t calibrate your sander, the application rates will not be accurate. CALIBRATE YOUR EQUIPMENT Calibration is an essential procedure to measure the pounds of salt and sand applied to the roadway at various auger settings in relation to truck speed. No matter how sophisticated or simplified your operations, always calibrate yearly. Because spreaders vary, calibrate each truck. Re-calibration is required if changes are made to the hydraulic system, if the augers have extensive wear or are resurfaced or replaced, or a different material is used. Follow the manufacturer s guidelines for calibration, and contact the manufacturer for training. For manual sander controls, refer to instructions at /publications or see the insert in the pocket of this handbook. Calibrate separately for salt/sand mix vs. salt or sand only. Remember: The auger plate must be in place during calibration. You are not calibrating the truck properly if the material is gravity-flowing. Place the chart in your truck and check it to see how much material will be applied at each setting, or ask your supervisor. 4

203 Before the Storm ANTI-ICING Anti-icing is often the most cost-effective and environmentally safe practice in certain winter road maintenance situations. You should consider heading in this direction. Anti-icing a proactive approach should be first in a series of strategies for most winter storms. By applying chemical freezing-point-depressant materials before a storm, you can prevent snow and ice from bonding to the pavement. Anti-icing requires about ¼ the material of deicing at 1 10 the overall cost, making it the least expensive option for improving traffic safety. Anti-icing is effective and cost-efficient when used correctly and approached with realistic expectations. Guidelines for anti-icing Anti-icing is often effective for heavy frosts. Anti-icing works best when combined with accurate road weather information. Early application is particularly important for frost or light freezing drizzle. Liquids are the most efficient and may be applied days in advance of an event. Pretreated salts will work at lower applications (lowest possible setting, less than 100 lbs/two-lane mile) closer to the expected event. See the Application Rate Guidelines on page 16 of this field handbook. What to do Apply only with stream nozzles to maintain some bare pavement between sprayed areas to reduce slipperiness. Fan spray is not recommended. Schedule applications on bridge decks and critical areas if temperature and conditions could produce frost or black ice. Consider spot-applications on hills, curves, and intersections if predicted conditions warrant. Use appropriate chemical for your pavement temperature range. See the chart on page of this field handbook. 5 Anti-icing can reduce airborne dust and salt particulates. Basic Concepts Before the Winter Before the Storm During the Storm After the Storm Application Rate Guidelines Materials and Quality Control Bibliography and Additional Resources Appendix

204 Before the Storm Use wisely. Chlorides can increase the salinity of soil, which can lead to compaction and erosion. Apply an anti-ice product during non-rush-hour traffic periods. When frost on the shoulder starts to move into the travel lanes, reapply anti-icing product. What not to do Don t anti-ice under blowing conditions, in areas prone to drifting, and anywhere else you would refrain from using salt. Be aware of areas that are prone to wind issues. Reapplication isn t always necessary if there is still a residual. The residual effect can remain for up to five days after application if precipitation or traffic wear-off does not dilute the initial application. Remember that the surface can refreeze when precipitation or moisture in the air dilutes the chemical. Don t apply MgCl 2 or CaCl 2 to a warm road (above 28 F pavement temperature). It can become slippery and cause crashes! Don t apply before predicted rain. For the first application or after a prolonged dry spell, apply liquids at half the rate (not half the concentration). On dry roads, liquids tend to mix with oil from vehicles and cause slippery conditions. Don t apply too much or the roadway may become slippery. Less is better. Always follow application recommendations. Equipment Anti-icing unit, i.e., transport vehicle with tank. Fan spray is not recommended. 6

205 PRETREATING AND PREWETTING SALT AND SAND Dry material bounces or blows off the road, so everyone should be either pretreating or prewetting dry material. Liquids also increase salt s effectiveness by jump-starting the melting process. Depending on the liquid used, it can lower salt s effective working temperature. Because pretreating and prewetting cause material to stick to the road, 20 to 30 percent less material is used saving money and reducing environmental impacts. Guidelines for pretreating Pretreating is mixing a liquid into the stockpile of salt or sand before it is applied. Unlike prewetting, it does not require equipment changes and requires no new capital investment for equipment. You can also switch from dry application to wet application immediately just turn down the application rate. Salt stockpile Treat the salt stockpile with a liquid deicing chemical. It may be purchased pretreated or mixed on site by the vendor. When treating the stockpile at the shop, apply at 6 to 10 gallons/ton. Because leach risk at a stockpile is increased, store it covered on an impervious pad. Sand stockpile Pretreat the stockpile to keep it flowable. Apply to stockpile at 4 to 6 gallons of salt brine/ton sand. Store the stockpile under cover. Before the Storm If you must use dry material, follow best practices to reduce bounce and scatter. Chemicals leaching from a stockpile into groundwater is a common problem. Basic Concepts Before the Winter Before the Storm During the Storm After the Storm Application Rate Guidelines Materials and Quality Control Bibliography and Additional Resources 7 Appendix

206 Apply wisely. We will never have a chance to recover the chlorides applied. Guidelines for prewetting Prewetting is adding a liquid to the salt as it is being applied either at the spinner or through a soaker pipe in the auger box to help it stick to the road better. Although prewetting requires some equipment changes, it provides flexibility to switch the chemical makeup depending on conditions. Salt brine, calcium, magnesium chlorides, and acetates may be used as prewetting agents. The optimal application rate is 8 to 14 gallons/ton for salt brine. Prewetting with other chemicals at the spinner can help reduce the application rate. Below 15 F, salt brine is less effective than other liquids and may freeze hoses and valves. Salt brine should be mixed at 23.3%. 8

207 During the Storm DEICING Deicing is a reactive operation in which a deicer is applied to the top of an accumulation of snow, ice, or frost that is already bonded to the pavement surface. Deicing generally costs more than anti-icing in materials, time, equipment, and environmental damage. Removing ice that has already bonded to the pavement can be difficult, and removing it mechanically can damage equipment and roads. Generally, enough ice must be melted chemically to break the bond between the ice and the pavement, which requires larger quantities of chemical than anti-icing. Use an appropriate amount of salt. Most oversalting can be prevented by using calibrated, speed-synchronized spreaders and good judgment in selecting application rates and truck speed. It is not necessary to melt all the snow or ice on the road with salt. This is an overuse of materials. Apply just enough to loosen the bond between the road and the ice so it can be plowed off. See the Application Rate Guidelines on pages of this handbook. Dilution of Solution (see page 2) also applies to deicing. Use cautiously. Many chemicals contain trace metals including cyanide, arsenic, lead, and mercury. The goal is not to melt everything. The goal is to penetrate through the ice and snow and break the bond so the pavement can be plowed. Basic Concepts Before the Winter Before the Storm During the Storm After the Storm Application Rate Guidelines Materials and Quality Control Bibliography and Additional Resources 9 Appendix

208 During the Storm Winter abrasives use has been documented as an air pollution concern. If you use a 50/50 salt/sand mix, you re generally either half right or half wrong. Using a salt/sand mix leads to overapplication of both materials. Sand that washes into a stream or lake may smother some small aquatic organisms. USING ABRASIVES Use winter sand and other abrasives when temperatures are too cold for deicing chemicals to be effective. But be aware that sand does not melt anything. It provides temporary traction, and only when it is on top. Sand also clogs sewers, ditches, and streams. As a result, avoid sand use as much as possible. A salt/sand mix is generally not recommended. Salt reduces the effectiveness of sand, and sand reduces the effectiveness of salt. However, a salt/sand mix may be helpful in limited situations such as a long freezing rain event where the salt is washed away quickly. A 25 to 50 percent sand/salt mix has been documented as effective in increasing friction by sticking the sand to the surface, like sandpaper. Use abrasives in slow-moving traffic areas such as intersections and curves. If your purpose is melting, use salt only. Salt is ineffective in cold weather, so use sand or an alternative chemical. Sand is not cheap when you consider the handling, cleanup, and disposal costs. Sweep up sand frequently, after each event if feasible. STANDARD PRACTICES Know the pavement temperatures and trends to help you use the right application at the right time. Generally use less chemical when temperatures are rising and more when they are falling. Don t apply dry salt (sodium chloride) at below 20 F pavement temperature. It will not melt fast enough to help and it will blow off the road into the ditch. Below 20 F, switch to other tools like CaCl 2 and MgCl 2 at curves, hills, and intersections to obtain maximum melting. If unavailable, use sand for traction. Adjust your spinner speed to the lowest setting possible, except at intersections. Drive at the slowest possible speed 17 to 25 mph slightly higher if prewetting. Don t let the traffic dictate your speed. Keep it slow to keep material on the road. Apply deicers in the center of the road or high side of the curve. 10

209 Set spinners lower to the ground to reduce bounce and scatter. Turn off auger when stopped, even briefly. Loading/hauling Set up and load on a level surface wherever possible. Maintain loading area. Keep it clear and smooth. Don t overload. Avoid spilling on units. Remove loose material from the exterior of the dump body. Watch for co-workers/pedestrians in or near the loading area. Effective use of plows Plow to remove snow and loose ice before deicing applications. If snow accumulates before or after applications, plowing directly before your next application will minimize product dilution. Plow first before applying deicers to avoid dilution of the salt. Coordinate plowing activities to eliminate windrows at intersections and prevent plowing off another operator s material. Never plow or blow snow over a bridge into the water or onto traffic below. Remove snow from roads as quickly as possible to reduce compaction; use of underbody blades helps remove compacted or slushy snow. Make use of carbide plow blade edges. Adjust blade angle to maximize cutting efficiency or snow throwing capabilities. Public safety/operator safety Perform your required CDL pre- and post-trip inspections. Make sure you re mentally and physically prepared to drive. Obey traffic laws. Use the seat belt. Clean lights and windows frequently. Flow with traffic as much as possible. Avoid sudden moves. Be alert to all surroundings. Demonstrate courtesy toward other drivers and pedestrians. 11 During the Storm Never use calcium chloride to open drains it is extremely toxic to aquatic systems. When slush begins to stiffen and kicks to the rear from vehicle tires, it s time to plow and then reapply chemical. Once chlorides enter the ground or surface water, they never go away. Basic Concepts Before the Winter Before the Storm During the Storm After the Storm Application Rate Guidelines Materials and Quality Control Bibliography and Additional Resources Appendix

210 During the Storm Make sure a shield is in place to control the application or you ll overapply salt. Be aware of spinner discharge at all times. Avoid pushing snow over bridge rails and onto roads below. Be alert to hazards such as downed power poles, stop lights, overhead structures, power lines, etc. Know the height of your truck box. Raise box only to move material to the back of the box. When raising the box, be certain no overhead obstacles are present. Be aware of changing braking abilities from a loaded box to an empty one. Keep others informed of changing conditions. Assist/report stranded motorists as necessary. Snow cloud Be aware of wind conditions and potential problems. Snow clouds can form during any plowing operation. A very slight snow cloud can temporarily block out any lighting configuration and increase chances of being hit from the rear. Reduce your speed to minimize snow clouds. Don t plow just to plow. If plowing (shoulder) isn t necessary when the wind is blowing, don t do it. 12

211 After the Storm After the storm, when snow and ice control operations have ended, evaluate what was done, how well it worked, and what could be changed to improve operations. Accurately record your material use at the end of your shift (see below). Attend a post-storm meeting in the shop to evaluate your operations. Look for opportunities to try new and improved practices. Clean and check all equipment. Report any hazards such as low-hanging branches, raised utilities, snow accumulation on bridges, or other potential problems. At the end of the season, clean and maintain the truck, tanks, brine-making systems, and pumps according to manufacturer specifications. Place all piles on an impervious pad and cover them. This includes salt and salt/sand mixes. STANDARD PRACTICES Documenting and charting Good documentation helps you use less material, reduce costs and environmental impacts, and run a more effective snow and ice control program. Unless you document and chart, you can t measure what you are doing. Track your material use. Understand the storm conditions and the target level of service for each route. Refine your procedures and material use based on observations. Share observations to improve operations and learn from each other. Use forms like those shown in the appendix of this field handbook to record and track your work and observations. Complete forms at the end of your shift. Turn in documentation forms to your supervisor. You can t manage what you don t measure. Some fish species are affected by impaired water, which is equivalent to about 1 to 1.5 tablespoons of salt in 5 gallons of water. Basic Concepts Before the Winter Before the Storm During the Storm After the Storm Application Rate Guidelines Materials and Quality Control Bibliography and Additional Resources 13 Appendix

212 After the Storm Fine-tuning your program Calibrate Yearly Use Application Rate Guidelines (pages 15-18) and Best Practices Check Weather and Pavement Conditions Track and Evaluate Treat Adjust Rates and Methods 14

213 Application Rate Guidelines Develop your own application rates using the guidelines on pages as a starting point and modify them incrementally over time to fit your needs. You can summarize information gathered from your truck logs into application rates for your area. Be aware, though, that sample rate charts vary greatly from one area to another, and most are very high. Make it a goal to reduce application rates while keeping our roads safe. You can reduce rates by following anti-icing and other strategies covered in this field handbook. GUIDELINES FOR DETERMINING APPLICATION RATES Sand/salt mix isn t advised but may help in some situations such as freezing rain. Always plow before applying chemical. For reapplication, start with the lowest rate in the range. High traffic volume will work salt into the snow and aid in melting so use a lower rate. Higher traffic speeds will blow salt off the road and hinder melting so increase use of prewetted materials. Use sand for short-term traction only. It will never melt anything. For application on a single lane, cut rates in half. For an 18- foot-wide road, use ¾ of the listed rate (i.e., multiply rate by 0.75). It is usually not cost-efficient to apply salt (sodium chloride) at pavement temperatures below 15 F. Salt spray damages roadside vegetation. Basic Concepts Before the Winter Before the Storm During the Storm After the Storm Application Rate Guidelines Materials and Quality Control Bibliography and Additional Resources 15 Appendix

214 Application Rate Guidelines Anti-icing Application Rate Guidelines These guidelines are a starting point. Reduce or increase rates incrementally based on your experience. Gallons/Lane Mile Condition MgCl 2 Salt Brine Other Products 1. Regularly scheduled applications 2. Prior to frost or black ice event 3. Prior to light or moderate snow Follow manufacturers recommendations Pavement Temp. F Pounds of Ice Melted Per Pound of Salt One Pound of Salt (NaCl) melts Melt Times lbs of ice 5 min lbs of ice 10 min lbs of ice 20 min lbs of ice 1 hour lbs of ice Dry salt is ineffective and will lbs of ice blow away before it melts anything lbs of ice lbs of ice It is not cost-efficient to apply salt (sodium chloride) at pavement temperatures less than 15 F. 16

215 Application Rate Guidelines Deicing Application Rate Guidelines 24 of pavement (typical two-lane road) These rates are not fixed values, but rather the middle of a range to be selected and adjusted by an agency according to its local conditions and experience. Pavement Temp. ( F) and Trend ( ) Weather Condition Maintenance Actions >30 Snow Plow, treat intersections only Lbs/ two-lane mile Salt Salt Dry Salt* Winter Sand Prewetted/ Prewetted/ (abrasives) Pretreated Pretreated With Salt With Other Brine Blends * Not recommended Frz. rain Apply chemical * Not recommended 30 Snow Plow & apply * Not chemical recommended Frz. rain Apply chemical * Not recommended Snow Plow & apply * Not chemical recommended Frz. rain Apply chemical * Not recommended Snow Plow & apply * Not chemical recommended Frz. rain Apply chemical * Snow or Plow & apply * 400 frz. rain chemical Snow Plow & apply * Not chemical recommended Frz. rain Apply chemical * Snow Plow & apply chemical * Not recommended Frz. rain Apply chemical * Snow or Plow & apply * 500 for frz. rain Frz. rain chemical 0 to 15 Snow Plow, treat Not with blends, recommended sand hazardous areas < 0 Snow Plow, treat with blends, sand hazardous areas Not recommended Not recommended ** Not recommended *Dry salt is not recommended. It is likely to blow off the road before it melts ice. **A blend of 6 8 gal/ton MgCl 2 or CaCl 2 added to NaCl can melt ice as low as spot treat as needed spot treat as needed Basic Concepts Before the Winter Before the Storm During the Storm After the Storm Application Rate Guidelines Materials and Quality Control Bibliography and Additional Resources 17 Appendix

216 Application Rate Guidelines How to use the table on page 17: 1. Select the row with the appropriate pavement temperature, temperature trend, and weather conditions. 2. Select the column that has the type of material you are using. 3. Find the box where the row and columns intersect to find the application rate. These rates are not fixed values, but rather the middle of a range to be selected and adjusted by your agency according to your local conditions and experience. 4. Compare those values to the calibration chart for your truck. 5. Dial the correct setting for the rate indicated on the Application Rate Guidelines. 6. If you are not treating a 24-foot-wide road (typical two-lane road), adjust the rate as follows: for application on a single lane, cut rates in half. For an 18-foot-wide road, use ¾ of the listed rate (i.e., multiply rate by 0.75). 18

217 Materials and Quality Control Chemical Melting Temperatures Multiple products can be used in a snow and ice control program. This chart helps you choose the correct product and apply it at the correct times. Chemical *NaCl (Sodium Chloride) Delivered as solid rock salt; also can be made into a brine. The basis of most deicing materials. Very corrosive. Inexpensive. *MgCl 2 (Magnesium Chloride) Delivered as flakes, pellets, or liquid. Often used to wet NaCl crystals to increase adherence to road and reduce melting points. Corrosive. Higher cost. *CaCl 2 (Calcium Chloride) Delivered as flakes, pellets, or liquid. Powerful deicer but extremely corrosive. Sometimes used incorrectly to open storm drains. Higher cost. CMA (Calcium Magnesium Acetate) Delivered as a powder, crystals, pellets, or liquid. Liquid CMA is used mainly on automated bridge deicing systems. Noncorrosive, biodegradable. Sometimes added to sodium chloride as a corrosion inhibitor. Alternative for areas where chloride use must be limited. Higher cost. Lowest Practical Melting Temperature 15 F 23.3% Concentration -10 F 27 to 30% -20 F 30% 20 F 32% Basic Concepts Before the Winter Before the Storm During the Storm After the Storm KAc (Potassium Acetate) Delivered as a liquid. Used on automated bridge deicing systems. Use for anti-icing, deicing, and prewetting. Non-corrosive, biodegradable. Alternative for areas where chloride use must be limited. Higher cost. -15 F 50% Application Rate Guidelines Winter Sand/Abrasives Winter sand is sand treated with brine or another blend. It is often used as an abrasive for low-temperature conditions when chemicals are not effective. Sand provides temporary traction and only works when it is on top of the ice. *Liquid chlorides are available with corrosion inhibitors. Never melts traction only Materials and Quality Control Bibliography and Additional Resources Appendix

218 Materials and Quality Control Material Conversions The following quick reference table and the formulas below will help you convert between tons and cubic yards. Weights will vary depending upon moisture content. Sand Salt Yards Tons Yards Tons To convert tons of clean sand to cubic yards: #tons divided by 1.4 = cubic yards 2. To convert cubic yards of clean sand to tons: #cubic yards multiplied by 1.4 = tons 3. To convert tons of winter sand to cubic yards: #tons divided by 1.37 = cubic yards 4. To convert cubic yards of winter sand to tons: #cubic yards multiplied by 1.37 = tons 5. To convert tons of straight salt to cubic yards: #tons divided by 1.08 = cubic yards 6. To convert cubic yards of straight salt to tons: #cubic yards multiplied by 1.08 = tons 20

219 MATERIALS TESTING Test your materials to ensure that they are delivered as ordered and will perform as needed. Refer to your contract or Material Safety Data Sheet (MSDS) for specific gravity. Testing liquids Before unloading the tanker truck, use a clean container to obtain a small sample (about 2 cups). Measure the specific gravity or percent saturation using a hydrometer or salimeter. Make sure you have the correct hydrometer for your material. Salt brine should have a salimeter reading of 85% or a hydrometer reading of 1.176, which equates to 23.3% salt in the brine. If the specific gravity is not within specifications, don t unload, and notify your supervisor. Testing sand Conduct a visual inspection of the material to make sure it is clean. Note that each user has its own specifications based on available materials. Materials and Quality Control Protect our roadside vegetation. Chlorides can damage vegetation at concentrations greater than 70 ppm (about 1/3 teaspoon of salt in 5 gallons). Basic Concepts Before the Winter Before the Storm During the Storm After the Storm Testing solid salt Make sure someone is present to watch the load being dumped and observe if it is wet. Test salt for moisture content. You are looking for a moisture content of less than or equal to 1.6%. (Check your agency s specification.) How to measure the moisture content of rock salt: Get your supplies: an accurate scale and ½ cup to 1 cup of salt taken from the pile, away from the outer edge. Microwave on high for 1 ½ minutes, stir and repeat. Record the information on the worksheet on page 22 and calculate % moisture. Application Rate Guidelines Materials and Quality Control Bibliography and Additional Resources 21 Appendix

220 BEST PRACTICES REFERENCE GUIDE VIII.B.2 Title: Ten Commandments for Snow Fighting Section: Personnel Training of New Employees Source: Unknown Originator: Unknown Date: Unknown Page 1 of 1 TEN COMMANDMENTS FOR SNOW FlGHTING 1. Thou shalt present thyself to thy job physically and mentally fit and properly clothed for any emergency in order to withstand the rigors of thy task 2. Thou shalt never enter thy cab without inspecting thy lights, windshield wipers, defrosters, flares, and other safety equipment. 3. Thou shalt know thy spreading and plowing routes as well as the performance of thy spinner and the life of thy plow blade. 4. Thou shalt faithfully remain alert in order to avoid guardrail, headers, stalled cars and mail boxes. Otherwise thee may smite thy windshield with thy head. 5. Thou s halt contain thy temper even though cars and trucks pass thee on both sides and tailgate thee too close for comfort. Anger only multiplies thy prospects of coming to grief by accident. 6. Thou shalt use thy radio as briefly as possible. Remember thy fellow workers may need to communicate in an emergency. 7. Thou shalt interrupt the flow of power to thy spreader before attempting to free any foreign objects or blockages if thee treasures thy fingers. 8. Thou shalt render thy truck and spreader out of gear and stoutly set thy brakes before dismounting from thy cab. 9. Thou shalt govern thy speed according to conditions, else thee may wind up with thy truck upside down. 10. Thou shalt mind thy manners on yon roadway, clearly signaling thy intentions and rendering assistance to stranded motorists, remembering that it is more blessed to give than to receive. If thee is alert, thee will remain safe and alive to render service to thy fellow man another day.

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Region NC. Page 1 of 6. Total Salt. Total Salt. Severity Index. Total Salt. Salt. Total Sand. Total Clear- Total Thaw- Lane.

Region NC. Page 1 of 6. Total Salt. Total Salt. Severity Index. Total Salt. Salt. Total Sand. Total Clear- Total Thaw- Lane. Notes: 1) Costs shown in table are estimated and do not include the 4.44% Administrative Costs; 2) Material Costs includes,, and other Deicing and icing Agents; 3) Equipment Costs are based on $60 per