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HomeMy WebLinkAboutItem B - Ice and Snow PolicyEUGENE CITY COUNCIL AGENDA ITEM SUMMARY Work Session: Resolution 4826 Adopting Ice and Snow Removal Policies and Repealing Resolution No. 4278 Meeting Date: February 28, 2005 Agenda Item Number: B Department: Public Works Staff Contact: Jeff Lankston www. cl. eugene, or. us Contact Telephone Number: 682-4813 ISSUE STATEMENT This is a work session requested by the Public Works Department to consider revision of the current Ice and Snow Removal Policy. A policy change would allow the use of anti-icing and de-icing agents for the purpose of ice and snow control on specified street sections. BACKGROUND On January 12, 2004, the council approved Resolution 4784, essentially amending Resolution 4278, which was passed in 1991 and which did not allow for the use of anti-icing or de-icing agents for the purpose of ice and snow control on streets. Resolution 4784 was adopted on a temporary basis through April 1, 2005. This resolution allows the use of anti-icing and de-icing agents on streets for the purpose of ice and snow control. Prior to being used, these products needed to be approved by the City Manager. Before Resolution 4784, sanding rock was the only material used for traction control. The application of sand is a reactive approach to ice and snow control in that sand is only applied when freezing conditions exist. Displacement of sand by vehicles and wind makes application prior to freezing conditions ineffective. Sanding for traction control has economic and environmental ramifications. Although sand is relatively inexpensive, a significant portion of ice and snow control costs are related to placing abrasives on the streets and then cleaning them up. Depending on the severity of the storm, several applications may be necessary on snow and ice routes. By using anti-icing and de-icing agents for ice and snow control, cost reductions are anticipated due to the reduction in repeat applications and the elimination of the clean-up process. Environmental impacts due to excessive sand use are also of concern. Dust particles created by vehicles crushing sanding rock can cause air quality concerns. For example, Denver, Colorado, has been cited by the Environmental Protection Agency (EPA) for excessive particulate matter (PM 10), otherwise known as brown cloud. Denver is now required to use liquid ice and snow control materials to maintain appropriate air quality conformity and compliance to EPA standards. Other cities and counties require liquid agents to meet EPA standards. Silt build-up in waterways from sand entering the stormwater system is another environmental concern. Sediment runoff can harm aquatic life and vegetation. An effort to clean up abrasives is made following all weather events to minimize property, personal and environmental damages. However, all material is not reclaimed due to displacement onto road shoulders and into stormwater inlets. L:\CMO\2005 Council Agendas\M050228\S050228B.doc Anti-icing and deicing products can be applied proactively to improve driver safety. These products can be applied prior to inclement winter weather, preventing frost, ice and/or snow from bonding to the road surface. Deicers can also be used after a weather event to help accelerate the melting process. This type of proactive approach to ice and snow control helps reduce the number of potential auto accidents and personal injuries. The Colorado Department of Transportation found that increasing the use of liquid deicers in five areas around the Denver metro area over a two-year period reduced accidents by an average of 67 percent. A similar study published by the Federal Highway Administration shows an 83 percent reduction in accidents over the course of three-years on a section of highway in Idaho. Within the City of Eugene's Urban Growth Boundary (UGB), both the Oregon Department of Transportation and Lane County Public Works use anti-icing and de-icing products on major streets and highways they maintain. Using products similar to those used by these agencies will help provide continuous conditions for the traveling public. The City has had the opportunity this season to apply an anti-icing agent on designated snow routes and has found the results to be highly effective. RELATED CITY POLICIES The Eugene City Council has adopted policies that direct the City to pursue sustainability (Resolution 4618), protect natural resources (Growth Management Policy # 17) and recover threatened Upper Willamette Spring Chinook Salmon (Resolution 4615) in its activities. The City of Eugene is committed to promoting a sustainable future that meets today's needs without compromising the ability of future generations to meet their needs, and accepts its responsibility to: · Support a stable, diverse and equitable economy · Protect the quality of the air, water, land and other natural resources · Conserve native vegetation, fish, wildlife and other ecosystems · Minimize human impacts on local, regional and worldwide ecosystems. Ice and snow control practices and products have been reviewed by the City of Eugene's Environmental Policy Team. The overall conclusion of studies reviewed by staff on de-icing/anti-icing products currently being used by Public Works is that environmental impacts to air and water quality, and aquatic life are unlikely to occur when these products are applied in accordance to established application methods and quantity rates (see attachments B through E, environmental studies and guidelines). Furthermore, reducing the amount of abrasives used for traction control helps improve air and water quality. Fewer applications of abrasives reduces fossil fuel emissions associated with diesel trucks and street sweepers. Reducing the quantity of abrasives applied and reclaimed for snow and ice control has a direct positive effect on the county landfill. Another goal of the City Council is to provide a "safe community." The appropriate use of snow and ice control products and techniques will allow for a more proactive approach to maintain safe streets during winter storms. COUNCIL OPTIONS 1. Amend the City's Ice and Snow Removal Policy by repealing Resolution 4278 and replacing it with a proposed new resolution (see Attachment A). By adopting the proposed new resolution, anti-icing L:\CMO\2005 Council Agendas\M050228\S050228B.doc and de-icing chemicals will be permitted in quantities appropriate for ice and snow control on streets, and staff will be able to move ahead with the purchase of application equipment. 2. Adopt the proposed new resolution but amend Section 3 to allow for the use of anti-icers and de- icers through April 1, 2006. Amending Section 3 would allow for the use of anti-icing and de-icing agents for an additional year. This option would result in operating inefficiencies as staff will be unable to purchase equipment for liquid de-icer application and, further, would not realize the economy of scale in purchasing liquid de-icer due to limited storage capacity. Annual rental rates are approximately 15 percent of the cost of a new liquid applicator. With this option the City will have spent $3,500 on rental fees over the two-year trial period. 3. Allow Resolution 4784 to sunset, at which time Resolution No. 4278 will go back into effect. This resolution states that the City will not use anti-icing or de-icing chemicals in quantities required for ice and snow control on streets. De-icing chemicals with corrosion inhibitors may be used in quantities necessary to keep sand stockpiles and sanding equipment workable. With this option, maintenance staff is limited to using only plows and sanding rock for providing safe road conditions for the traveling public during winter storms. CITY MANAGER'S RECOMMENDATION The City Manager recommends that the City's Ice and Snow Removal Policy be amended by adopting the proposed resolution (Option 1). SUGGESTED MOTION Move to adopt Resolution 4826 adopting ice and snow removal policies and repealing Resolution No. 4278. ATTACHMENTS A. Proposed resolution (Resolution No. 4826) B. Studies of Environmental Effects of Magnesium Chloride Deicer in Colorado Prof. William M. Lewis Western Environmental Analysts www. dot. state, co.us/publications/PDFFiles/magchlorideenveffects.pdf C. Report on the Effects of Calcium Magnesium Acetate De-icing Materials on the Water Quality of Bear Creek, Clackamas County, Oregon, 1999 http ://or.water.usgs.gov/pubs_dir/Pdf/00-4092.pdf D. City of Boulder/Weekly Information Packet, January 24, 2002 E. Guidelines for Anti-icing/Deicing Note: Complete copy of attachments B and C can be found in the Council Office. FOR MORE INFORMATION Staff Contact: Jeff Lankston, Public Works Maintenance Director Telephone: 682-4813 Staff E-Mail: jeff. lankston~ci.eugene.or.us L:\CMO\2005 Council Agendas\M050228\S050228B.doc ATTACHMENT A RESOLUTION NO. 4826 A RESOLUTION ADOPTING ICE AND SNOW REMOVAL POLICIES AND REPEALING RESOLUTION NO. 4278. RECITALS: A. Ice and snow storms can cause a severe economic impact on the community, depending on the intensity and duration of the storm. It is important to keep transportation systems as operational and safe as possible during ice/snow storms while minimizing the economical impact of those operations on the community. B. Sections 5.677 to 5.687 of the Eugene Code, 1971 authorize the declaration of a Snow Emergency, and prescribe the manner in which parking may be restricted on certain designated priority routes. C. Streets are placed on these priority routes after reviewing criteria such as, but not limited to: traffic volumes, Lane Transit District bus routes, emergency service locations (fire stations, Roosevelt Maintenance Facility, police station, hospitals), geographic constraints such as steep hills, historical hazardous traffic locations, and elevated structures such as bridges and overpasses. D. At the request of the City Manager the City's Public Works Department developed an Ice/Snow Plan to facilitate achievement of the City's general goal of keeping the streets as safe as possible during ice and snow storms with the least economic and environmental impacts on the community, which was adopted by Resolution No. 4278 on October 31, 1991. The City Manager requested the City's Public Works Department to review the adopted Ice/Snow Plan to determine whether any revisions were necessary at this time. As a result of that review, a new Ice/Snow Plan has been developed that includes provisions allowing the use of deicers/anti-icers on City maintained streets. E. It would be in the public interest that Resolution No. 4278 and the Ice and Snow Removal Policies adopted therein be repealed, and the policies relating to the manner in which the City responds to ice and snow emergencies as hereinafter set forth be adopted by the Council. NOW, THEREFORE, BE IT RESOLVED BY THE CITY COUNCIL OF THE CITY OF EUGENE, a Municipal Corporation of the State of Oregon, that the following constitutes the City's policies for ice and snow control: Section 1. These policies apply to the City of Eugene street system and to streets for which the City has special maintenance agreements with other jurisdictions for ice and snow control. These policies do not apply to the Eugene Airport because snow removal practices and procedures such as plowing, anti-icing, sanding, and deicing operations at the Airport are Resolution- 1 influenced by the Federal Aviation Administration and the operating requirements of commercial air carriers. Section 2. Snow plowing, deicing/anti-icing, and sanding will be performed along designated snow routes as snowfall occurs. Priorities may be altered to address specific problem areas. Streets that are not designated snow routes will not receive ice and snow control measures. Section 3. The City does not have a bare pavement policy. Snow plowing, deicing/anti- icing, and sanding operations are intended to provide the prudent motorist with a reasonably safe traveling surface. During heavy snowfall or severe icing conditions motorists may need to install chains or other traction devices. Section 4. Deicing chemicals with corrosion inhibitors may be used in quantities necessary to keep sand stockpiles and sanding equipment workable. Section 5. Ice and snow control operations will consist of the application of deicing/anti- icing agents and abrasives along designated snow routes as deemed needed. When accumulated snow becomes compacted and plowing becomes ineffective, deicing agents and abrasives will be used as in normal ice and snow control operations. Section 6. During ice and snow control operations deiciers/anti-icers and abrasives will normally be applied within 100 feet of a controlled intersection, on bridges, overpasses and their approaches, and along curves and steep grades. The City Manager or designee may alter this policy to address unique storm conditions. Section 7. Resolution No. 4278 is repealed as of the effective date of this Resolution. Section 8. This Resolution shall become effective immediately upon its adoption. The foregoing Resolution adopted the __ day of ., 2005. City Recorder Resolution - 2 ATTACHMENT B Studies of Environmental Effects of Magnesium Chloride Deicer in Colorado , · by Principal Investigator Prof. William M, Lewis Westem Environmental Analysts Report No. CDOT-DTD-R-99-10 Final Report Prepared by Colorado Department of Transportation Research Branch November 1999 Colorado Department of Transportation Research Branch 4201 E. Arkansas Ave. Denver, CO 80222 (303) 757-9506 Technical Report Documentation Page 1. ReportNo. 2. Government Accession No. 3. Recipient's Catalog No. CDOT-DTD-R-99-10 4. Title and Subtitle 5. Report Date STUDIES OF ENVIRONMENTAL EFFECTS OF MAGNESIUM CHLORIDE November 1999 DEICER IN COLORADO 6. Performing Organization Code 7. Author(s) 8. Performing Organization Report No. William M. Lewis, Jr. 9. Performing Organization Name and Address 10. Work Unit No. (TRAIS) Western Environmental Analysts 2525 Arapahoe, Suite E4-282 Boulder, CO 80302 11. Contract or Grant No. 12. Sponsoring Agency Name and Address 13. Type of Report and Period Covered Colorado Department of Transportation 4201 East Arkansas Avenue Final Report, 3 years Denver, Colorado 80222 14. Sponsoring Agency Code 15. Supplementary Notes Prepared in cooperation with the U.S. Department of Transportation, Federal Highway Administration 16. Abstract The overall conclusion of the study is that application of magnesium chloride deicer having a chemical composition and application rate similar to those of 199%98 is highly unlikely to cause or contribute to environmental damage at distances greater than 20 yards from the roadway. Even very close to the roadway, the potential of magnesium chloride deicer to cause environmental damage is probably much smaller than that of other factors related to road use and maintenance, including pollution of highway surfaces by vehicles and use of salt and sand mixtures to promote traction in winter. Magnesium chloride deicer may offer net environmental benefits if its use leads to a reduction in the quantity of salt and sand applied to roadways. The environmental safety of magnesium chloride deicer depends, however, on low concentrations of contaminants and avoidance of rust inhibitors containing phosphorus. Appropriate specifications for vendors and routine testing can insure the continued environmental acceptability of magnesium chloride deicers. Implementation Deicers provided by vendors should be monitored independently by CDOT for chemical characteristics. Any significant changes in processing or source material should be disclosed by the vendor. Colorado-based specifications should be developed for vendors. Independent specifications for low elevation could be developed, or the more stringent high elevation specifications can be applied to all purchases. 17. Key Words 18. Distribution Statement winter maintenance, deicing, corrosion inhibitors, aquatic life No restriction. This document is available to the public through: National Technical Information Service 5825 Port Royal Road Springfield, Virginia 19. Security Classif. (of this report) 20. Security Classif. (of this page) 21. No. of Pages 22. Price None None 101 i Executive Summary 1. The Colorado Department of Transportation plans to increase its use of magnesium chloride liquid deicers. Advantages of deicer solutions on roadways at high elevation include reduction in the use of salt and sand mixtures and improvement of road conditions during storms beyond what is possible by the use of sand and salt mixtures alone. 2. In preparation for increased use of magnesium chloride deicers on roadways at high elevations, the Colorado Department of Transportation (CDOT) initiated environmental investigations during late 1996. These environmental investigations focused on the effects of magnesium chloride deicers on water quality and aquatic ecosystems. The studies included analysis of water quality and aquatic communities as well as biotoxicity testing. 3. The field and laboratory studies of magnesium chloride deicers were preceded by a literature review. The review showed that magnesium and chloride, the main ingredients of magnesium chloride deicers, are unlikely to produce adverse environmental effects except under very unusual circumstances. Chloride may damage vegetation very close to roadways, but is diluted by runoff to such an extent that it is very unlikely to exceed the concentrations that are known to be harmful to aquatic life. Aside from the main ingredients, magnesium chloride deicers can be expected to contain rust inhibitors as well as substances in lower amounts that are included inadvertently. Rust inhibitors and minor constituents of deicers have seldom been studied. 4. The expected dilution of deicers on roadways was estimated as one means of evaluating the expected concentrations of deicer components in runoff as it enters the environment. The median expected dilution of deicer is approximately 1 to 500 prior to its exit ii from the roadway, but dilution will vary considerably in relation to rate of application, amount of runoff, and other site-specific factors. 5. Analysis of the deicing mixtures that were in use by CDOT during the winter of 1996- 97 showed unexpectedly high concentrations of lead, zinc, and cadmium as well as phosphorus. Ratios of lead, zinc, and cadmium to stream standards exceeded the desired threshold of 500. CDOT tightened its restrictions on vendors for supplies purchased for the winter of 1997-98. 6. Deicers provided by vendors for winter 1997-98 showed lower concentrations of metals and phosphorus than deicer provided by the same vendors during the previous winter. Ratios of contaminants to maximum allowable chronic concentrations in stream water were all below 500, as necessary to assure appropriate dilution prior to entering the environment. 7. Organic materials are expected components of deicers because rust inhibitors may consist of organic compounds. An analysis of the deicing solutions in use during 1996-97 showed that the deicers contained between 280 and 850 mg/L of organic carbon, and that this amount of organic matter would be expected to induce a total oxygen demand between 750 and 2200 mg of oxygen for every liter of deicer applied to the roadway. Deicer supplied for winter 1997-98 contained between 1200 and 2800 mg/L of organic carbon, and would have had oxygen demand higher than that of the previous year (3150-7500 mg for every liter of deicer). Given the extensive dilution of the deicer on and very near the roadway prior to entering the environment, however, this potential oxygen demand appears to present no environmental threat through the depletion of oxygen in streams or other aquatic environments. 8. The biochemical oxygen demand of deicers was measured experimentally. Control sites (i.e., sites not receiving deicers) showed biochemical oxygen demand between 0.04 and 0.11 mg O2/L/day. No significant increase in BOD could be detected as a result of the addition of 111 0.3% deicer solution. In addition, no significant change in BOD could be observed as a result of the addition of salt and sand (0.6% by mass). 9. Tadpoles of the boreal toad were subjected to biotoxicity testing under controlled laboratory conditions through exposure to a range of concentrations of 1996-97 deicer. The boreal toad is of particular interest because of its status as an endangered species, and its presence in aquatic environments near roadways that receive deicer. The tadpoles showed no mortality over 96-hour intervals at deicer concentrations of 0.1%, which is close to the expected median concentration of deicer concentrations in runoff as it exits the roadway. The concentration of deicer required to cause 50°,4 mortality (LD$0) among tadpoles over a 96-hour period was estimated as 0.32%. Tadpoles were similarly affected by solutions of pure magnesium chloride (LD50--0.65%). Repetition of testing with 1997-98 deicer produced similar results. A sublethal (physiological stress) test was added for 1997-98 deicer; it showed physiological stress at or above 0.1% deicer. The no effect concentration for the sublethal test probably lies in the vicinity of 0.02% deicer. 10. Juvenile rainbow trout were tested with 1996-97 deicer for response to varying concentrations of deicer. The threshold for mortality over 96-hour exposure intervals was approximately 0.5%. The LDS0 for rainbow trout was estimated as 1.4% magnesium chloride deicer. Results were similar for 1997-98 deicer. 11. The aquatic invertebrate Ceriodaphnia was tested for response to a range of magnesium chloride deicer solutions over an interval of 48 hours. The threshold of mortality for Ceriodaphnia was approximately 0.1%. The LDS0 for Ceriodaphnia was estimated as 0.19°,4 (48 hours). A test of reproductive capability was also performed on Ceriodaphnia. The reproductive test indicates the onset of negative physiological effects for Ceriodaphnia at about iv 0.1% deicer. Both mortality and reproductive tests were repeated with 1997-98 deicer; results were similar to those of the previous year. 12. The algal genus Selenastrum was tested with 1997-98 deicer for response to magnesium chloride deicer over intervals of 96 hours. The test showed significant suppression of division rate for the algal cells occurring at deicer concentrations slightly in excess of 0.1%. Other indicators of physiological stress appeared at concentrations of approximately 1%. 13. In overview, toxicity tests show that various kinds of aquatic organisms differ in their sensitivity to magnesium chloride deicer. The most sensitive kinds of organisms included in these tests begin to show observable effects at about 0.1% magnesium chloride deicer during exposures ranging from 48 to 168 hours. Because of the presence of melt water, magnesium chloride deicer applied to roadways is diluted to approximately 0.2% prior to leaving the roadway, and an additional amount (to less than 0.1%) within short distances (e.g., 20 yards) of the roadway. 14. Mass transport was estimated from field data for magnesium, chloride, and sodium at 6 field sites (stream study segments) during 1997 and 1998. The amount of magnesium added in the form of magnesium chloride to roadways greatly increased the total annual transport of magnesium. Addition of magnesium chloride raised the concentrations of magnesium in streams by as much as three times above baseline concentrations of 2-3mg/L. Winter concentrations were most strongly affected bemuse stream discharge is low during winter, and thus dilutes the magnesium less than during spring. Even though changes in concentration were substantial, they fell well within the natural range of magnesium concentrations in Colorado waters and raise no specific environmental concerns. V 15. For chloride, two different sources are likely to raise concentrations and mass transport above background: magnesium chloride and salt with sand. Background concentrations of chloride are very low (0-2 mg/L); the combination of magnesium chloride and salt with sand raises these background concentrations by 50 to 100 mg/L during winter, when dilution is lowest. Even so, the peak concentrations were below concentrations that could be considered potentially hannfid to the most sensitive forms of aquatic life. Annual transport of chloride is accounted for mainly by chloride added to highways in the form of salt with sand. When deicer and salt with sand are applied together, magnesium chloride deicer accounts for 10 - 50% of the total. 16. Sodium is added to highways as salt with sand, but not as a component of magnesium chloride. Use of salt with sand raises the peak concentrations of sodium in stream waters from the range 2-5 mg/L to the range 20-:50 mg/L. These concentrations are not considered environmentally damaging, however. The sodium added as salt with sand can be a high percentage of the natural annual transport. 17. Concentrations of other inorganic substances were studied at the 6 field sites through routine monitoring extending from late 1997 to spring 1999. Substances that were monitored included arsenic, cadmium, chromium, copper, lead, mercury, and zinc. In addition, hardness of the water was measured at each site on each monitoring date because regulatory limits for some metals are determined on the basis of hardness. The amounts of substances in the water were undetectable or rarely detectable in most cases. Cadmium, copper, and zinc were detected commonly at some sites. The analysis, therefore, focused on cadmium, copper, and zinc. For sites that are unaffected by mine drainage (main stem of Straight Creek and Laskey Gulch), intersite comparisons show that the application of magnesium chloride deicer has no detectable effect on the concentrations of the substances that were analyzed; concentrations were vi consistently far below regulatory limits. The other four sites are affected to varying degrees by mine drainage. Mine drainage causes consistent exceedances of standards on upper Clear Creek and lower North Clear Creek. The amounts of metals transported in watersheds that are either affected or tm_affected by mine drainage far exceed the amounts that are added to roadways with magnesium chloride deicer. 18. Deicer contributed less than 5% to transport of phosphorus when no phosphorus- containing rust inhibitors were used. 19. Comparisons were made of algal communities at three locations receiving deicer and three locations not receiving deicer (controls). Analysis of the algal communities indicates no statistically significant difference in the algal communities of control and treatment sites. 20. During spring of 1998, samples were taken of runoff originating from portions of 1- 70 receiving magnesium chloride deicer. The samples were taken just following a storm during which deicer and salt with sand had been applied, and consisted of a series of transects beginning at the side of the highway and moving along drainage paths leading to the nearest large stream. The purpose of the sampling was to determine the degree and speed of dilution for deicers through chemical analysis ofrunoffwater. The results showed that dilutions were at a minimum 5000 fold and typically 10,000 fold or more at short distances from the roadway (e.g., 20 yds). 21. Water quality was studied in two wetlands, both of which support breeding populations of the boreal toad. One wetland (the north wetland) does not receive hi'ghway drainage because it is up slope of the highway, whereas a nearby wetland (south wetland) receives highway drainage from 1-70. Studies of the concentrations of major ions, and especially magnesium, indicate that the south wetland received concentrations of deicer not exceeding 0.002% during the toad breeding season (June to early July). Concentrations of metals and vii related substances were primarily undeteetable except for copper and zinc. Concentrations of copper and zinc were higher in the south wetland, below the highway, than in the north wetland. Mass balance studies showed, however, that the proportion of these elements that can be traced to deicing compounds does not exceed 0.002%. Other highway-derived water quality influences (wear of metallic parts, lubricants, salt and sand applications) may account for concentrations of copper and zinc reaching or exceeding the aquatic life standard, or geologic factors may be involved. 22. The overall conclusion of the study is that application of magnesium chloride deicer having a chemical composition and application rate similar to those of 1997-98 is highly unlikely to cause or contribute to environmental damage at distances greater than 20 yds from the roadway. Even very close to the roadway, the potential of magnesium chloride deicer to cause environmental damage is probably much smaller than that of other factors related to road use and maintenance, including pollution of highway surfaces by vehicles and use of salt and sand mixtures to promote traction in winter. Magnesium chloride deicer may offer net environmental benefits if its use leads to a reduction in the quantity of salt and sand applied to roadways. The environmental safety of magnesium chloride deicer depends, however, on low concentrations of contaminants and avoidance of rust inhibitors containing phosphorus. ApprOpriate specifications for vendors and routine testing can insure the continued environmental acceptability of magnesium chloride deicers. 70 especially since use of magnesium chloride might allow reduction in the use ofsalt and sand, and thus reduce the presence of trace materials that are carried by salt and sand. General Conclusions The overall conclusion of the study is that application of magnesium chloride deicer having a chemical composition and application rate similar to those of 1997-98 is highly unlikely to cause or contribute to environmental damage at distances greater than 20 yds from the roadway. Even very close to the roadway, the potential of magnesium chloride deicer to cause environmental damage is probably much smaller than that of other factors related to road use and maintenance, including pollution of highway surfaces by vehicles and use of salt and sand mixtures to promote traction in winter. Magnesium chloride deicer may offer net environmental benefits if its use leads to a reduction in the quantity of salt and sand applied to roadways. The environmental safety of magnesium chloride deicer depends, however, on low concentrations of contaminants and avoidance of rust inhibitors containing phosphorus. Appropriate specifications for vendors and routine testing can insure the continued environmental acceptability of magnesium chloride deicers. Acknowledgmems This study was supported by the Research Division of the Colorado Department of Transportation. The study benefitted from the advice and assistance of the Intemgency Planning ATTACHMENT C U.S. Department of the Interior U.S. Geological Survey Prepared in cooperation with the Oregon Department of Transportation The Effect of Calcium Magnesium Acetate (CMA) Deicing Material on the Water Quality of Bear Creek, Clackamas County, Oregon, 1999 Water-Resources Investigations Report 00-4092 U.S. DEPARTMENT OF THE INTERIOR BRUCE BABBIT, Secretary U.S. GEOLOGICAL SURVEY Charles G. Groat, Director Any use of trade, product, or firm names in this publication is for descriptive purposes only and does not imply endorsement by the U.S. Government. For additional information contact: Copies of this report can be purchased from: District Chief U.S. Geological Survey U.S. Geological Survey 10615 S.E. Cherry Blossom Drive Branch of Information Services Portland, OR 97216-3159 Box 25286, Federal Center E-mail: info-or@usgs.gov Denver, CO 80225-0046 Internet: http://oregon.usgs.gov The Effect of Calcium Magnesium Acetate (CMA) Deicing Material on the Water Quality of Bear Creek, Clackamas County, Oregon, 1999 By Dwight Q. Tanner andTamara M. Wood Abstract INTRODUCTION This report presents the results of a study by the Calcium magnesium acetate (CMA) is a useful deic- U.S. Geological Survey, done in cooperation with the lng material for roadways. Its advantages over sodium- and Oregon Department of Transportation (ODOT), to calcium-chloride salts include less corrosiveness to automo- evaluate the effects of the highway deicing material, biles and to highway materials, and. less toxicity to roadside calcium magnesium acetate (CMA), on the water qual- vegetation (Transportation Research Board, 1991). The ity of Bear Creek, in the Cascade Range of Oregon. main disadvantage of CMA is its higher cost, which is ODOT began using CMA (an alternative deicer that 20 times that of salt (Transportation Research Board, 1991, has fewer adverse environmental effects than road salt) in the mid-1990s and began this study with the USGS p. 1). The adverse environmental effects of CMA used as an to ensure that there were no unexpected effects on the anti-icing material are mainly related to the acetate ion, C2H302-. Acetate can increase the biochemical oxygen water quality of Bear Creek. Streamflow, precipitation, demand (BOD) of streams, causing the depletion of dis- dissolved oxygen, pH, specific conductance, and water solved oxygen (Connolly and others, 1990). The conductiv- temperature were measured continuously through the ity of the water may increase with the addition of calcium, 1998-99 winter, magnesium, and acetate ions, and the addition of acetate to There was no measurable effect of the applica- a stream may increase the alkalinity, and consequently the tion of CMA to Highway 26 on the biochemical pH (Homer, 1988). oxygen demand (BOD), calcium concentration, or magnesium concentration of Bear Creek and its tribu- The effects of CMA on an environmentally sensitive taries. BOD was small in all of the water samples, area such as the Cascade Range have not been fully evalu- some of which were collected before CMA applica- ate& In December 1998, the Oregon Department of Trans- tion, and some of which were collected after applica- portation (ODOT) entered into a cooperative agreement tion. Five-day BOD values ranged from 0.1 milli- with the U. S. Geological Survey to measure and evaluate grams per liter to 1.5 milligrams per liter, and 20-day the effects of CMA highway applications on the water qual- BOD values ranged from 0.2 milligrams per liter to ity of Bear Creek, a tributary to the Sandy River located on 2.0 milligrams per liter, the western slope of the Cascade Range in Oregon (fig. 1). Dissolved copper concentrations in a small Bear Creek drains a small watershed that supports a cold- tributary ditch on the north side of Highway 26 water fishery. It is an ideal site for this study because CMA exceeded the U.S. Environmental Protection Agency is applied to Highway 26 at this elevation several times a aquatic life criteria on three occasions. These exceed- year as part of ODOT's normal operations. The small size ances were probably not caused by the application of of the creek and the fact that it closely parallels the highway CMA because (1) one of the samples was a back- for about 1 mile represent the maximum probable effect for ground sample (no recent CMA application), and (2) direct runoff of CMA into a receiving stream. Therefore, if dissolved copper was not detected in Bear Creek water the impacts of CMA application on Bear Creek are small, samples to which CMA was added during laboratory ODOT can proceed with some confidence that impacts on experiments, other streams throughout Oregon will probably be small. SUMMARY AND CONCLUSIONS Connolly, J.P., Paquin, P.R., Mulligan, T.J., Wu, K.B., and Davanzo, L., 1990, Calcium magnesium acetate bio- There were no discernible differences in BOD (bio- degradation and its impact on surface waters: In Gold- chemical oxygen demand), calcium concentration, or mag- man, C.R., and Malyj, G.J., (eds.) The Environmental nesium concentration for Bear Creek and its tributaries Impact of Highway Deicing--Proceedings of a sym- before and after the application of CMA to U.S. Highway posium held October 13, 1989 at the University of 26. Concentrations of BOD in the water samples were California, Davis Campus: Institute of Ecology, no. small. Five-day BOD values ranged from 0.1 mg/L to 33, p. 140-156. 1.5 mg/L, and 20-day BOD values ranged from 0.2 mg/L Hem, J.D., 1989, Study and interpretation of the chemical to 2.0 mg/L. The samples from the North Ditch site had rel- characteristics of natural water (3rd ed.): U.S. Geo- atively large values for 20-day BOD, chemical oxygen logical Survey Water-Supply Paper 2254, 263 p. demand, and dissolved organic carbon, possibly due to Homer, R.R., 1988, National Cooperative Highway enrichment from sources of organic matter not related to Research Program Report 305: Environmental moni- CMA application, toting and evaluation of calcium magnesium acetate When CMA solutions were added to Bear Creek (CMA): Transportation Research Board, National water samples to make spiked samples of known concentra- Research Council, Washington D.C., 27 p. tion, the resulting BODs were so large that even after 20 Leonard, A.R., and Collins, C.A., 1983, Ground water in days of incubation, dissolved oxygen was still being con- the northern part of Clackamas County, Oregon: U.S. sumed. The ultimate BODs of the spiked samples were cai- Geological Survey Open-File Report 80-1049, 85 p. culated stoichiomettically, and they showed agreement with Owenby, J.R., and Ezell, D.S., 1992, Monthly station nor- the 20-day BOD values, mals of temperature, precipitation, and heating and Dissolved copper concentrations in North Ditch cooling degree days, 1961-90: Climatography of the exceeded the U.S. Environmental Protection Agency United States No. 81, National Oceanic and Atmo- aquatic life criterion on several occasions. These exceed- spheric Administration, variously paged. ances were probably not caused by the application of CMA Peck, D.L., Griggs, A.B. Schlicker, H.G., Wells, F.G., and because (1) one of the samples was a background sample Dole, H.M., 1964, Geology of the central and north- (no recent CMA application), and (2) dissolved copper was em parts of the Western Cascade Range in Oregon: not detected in the CMA spikes. U.S. Geological Survey Professional Paper 449, 56 p. The quality control portion of the study included field Transportation Research Board, 1991, Highway deicing-- blanks and replicate samples. Field blanks for BOD and Comparing salt and calcium magnesium acetate-- dissolved organic carbon showed no significant contamina- National Research Council: Washington D.C., Special tion. Field blanks for major ions and trace elements showed Report 235, 170 p. no detections, but dissolved nitrate and dissolved ortho- U.S. Environmental Protection Agency, 1999, National phosphorus were detected at or near the minimum reporting Recommended Water Quality Criteria--Correction: level. The replicate samples showed small variability. EPA 822-Z-99-001, 25 p. Wise, D.L., Levendis, Y.A., and Metghalchi, M., eds, 1991, Calcium magnesium acetate--An emerging bulk REFERENCES CITED chemical for environmental applications--Industrial Chemistry Library--Volume 2: New York, Elsevier American Public Health Association, American Water Science Publishers, 219 p. Works Association, and Water Environment Federa- Young, G.K, Stein, S., Cole, P., Kammer, T., Graziano, F., tion, 1998, Standard methods for the examination of and Bank, F., 1996, Evaluation and management of water and wastewater (20th ed.): Washington, D.C., highway runoff water quality, 1996: Federal High- American Public Health Association, [variously way Administration Final Report FHWA-PD-96-032, paged]. 480 p. 16 ATTACHMENT D WEEKLY INFORMATION PACKET DATE: January 24, 2002 TO: Mayor and Members of City Council FROM: Ron Secrist, City Manager Christine Andersen, Deputy City Manager for Environmental Services Tracy Winfree, Acting Director of Public Works for Transportation Stephanie Grainger, Transportation & Utilities Maintenance Coordinator SUBJECT: Information Item: Snow and Ice Control Materials and Environmental Impacts Purpose: To provide City Council with information on the materials used in our snow and ice control program and to address questions asked about impacts to aluminum and vegetation from these products. Background: The city of Boulder has been a leader in the Front Range in the use of alternative snow and ice control materials. The city has worked closely with and followed the recommendations of the Denver Regional Council of Governments (DRCOG) as well as the Regional Air Quality Council (RAQC) in its material choices. Transportation Maintenance used salt and sand in its snow and ice operations until 1995. In 1995, Transportation Maintenance began testing a new liquid deicer consisting of magnesium chloride mixed with a corrosion inhibitor. In 1996, the use of"Realite"- a lightweight, porous rock - began being used instead of sand for traction. Realite was treated with the magnesium chloride as a dust suppressant. The advantage of Realite over sand was that it did not break down as much as sand and, therefore, was less of a contributor to PM10 (tiny dust particles smaller than 10 microns). The Environmental Protection Agency set air quality standards for PM10 in 1987 to protect public health. In 1998, staff began testing a new crystallized deicer called "Ice Slicer." The advantages of using a crystallized deicer are that unlike other rock traction materials (1) the deicer works to melt the snow/ice, and (2) the crystals melt and do not need to be swept up following a storm. Since 1998, staff has been testing new liquid deicers as they come on the market. A product called "Ice Ban" has been used in extremely cold temperatures as it has the ability to melt down to -40 degrees. Ice Ban is used sparingly because it leaves a sticky residue and has an odor. In the 2001-2002 snow season, staff began testing a liquid deicer called "Caliber M1000." Material Contents of Products Being Used: Ice Ban is a liquid deicer that is derived from the concentrated liquid residue of the fermentation and distillation of alcohol and the processing of other agricultural products. This product is considered "organic" by the industry because it does not contain chlorides. Caliber MIO00 is a blend of a 30 percent magnesium chloride solution and 70 percent corn byproducts (basically magnesium chloride and Ice Ban mixed together). Ice Slicer is a naturally occurring complex chloride ice-melter consisting of synergistic trace minerals plus magnesium, potassium, sodium, and calcium chlorides, and grit. The material is mined in Utah. Realite is only used in limited snow situations. It is a lightweight shale material that has been baked at 2000 degrees to make it harder, lighter and more porous. It is saturated in a calcium chloride solution. Since Realite is coated with a dust suppressant, and due to the durability of the product, the degradation is delayed and dust particles tend to bind together, keeping the fines from becoming airborne and contributing to the "brown cloud." However, DRCOG and the RAQC recommend the crystallized deicers that dissolve over any traction material that breaks down. Environmental Effects: Numerous studies have been done over the years by the federal and state governments, departments of transportation, and by the material vendors to determine the environmental impacts of the deicers and traction materials being used throughout the country. On an ongoing basis, city water quality staff has conducted water quality testing of the materials the city is using in its snow and ice control programs and have found no significant impacts to-date. Staff tries to stay current on the latest reports and makes its decisions on material use based on recommendations of DRCOG and RAQC as well as on recommendations and standards set by the industry and environmental groups. Attached is a matrix from a study showing the effects of magnesium chloride on vegetation, soils, water quality, aquatic life, and humans and mammals (Attachment 1). Levelton Engineering Ltd of Richmond, British Columbia did this matrix in 1998 as part of a report to the Insurance Corporation of British Columbia. Corrosion: The industry measures corrosion based on "PNSDOT" standards. Transportation agencies within the states of Washington, Oregon, Montana and Idaho and the province of British Columbia formed a committee several years ago to develop specifications for chemicals related to snow and ice control. The committee has evolved to become the Pacific Northwest Snowfighters (PNS) Association. The association has developed performance specifications for corrosion. Caliber MlO00 deicer passes the tests developed by the National Association of Corrosion Engineers Standard TM-02-69 as modified by the PNS. The specification set by the PNS is that materials must be 70 percent less corrosive than salt. Caliber MIO00 corrosion rate is 22 for metals (78 percent less corrosive than salt). For comparison, the corrosion rate for distilled water is zero and 100 for rock salt (sodium chloride). Staff could not find a PNS rating for the Ice Slicerwe have been using and the product does not show on the PNS approved materials list. (PNS does show a rating for a new enhanced Ice Slicer.) However, other non-PNS tests and standards (including the Utah Department of Transportation approved testing method - American Standard Testing Methodology) show a corrosion rate of 30. Corrosion tests on cold rolled steel, galvanized steel, and aluminum show the following penetration rates per year for Ice Slicer. Type of Metal Penetration/Year Converted to Inches/Year Cold Rolled Steel 4.643 millimeters .18"/year Galvanized Steel 25.44 microns .001 "/year Aluminum 18.55 microns .00073'/year Testing was done on untreated steel and aluminum (100 hours of spray testing). VVhen materials are applied to a roadway, they become diluted as they melt the snow and ice. Dilution of the material will vary with the type of storm and amount of precipitation received. The city has not experienced increased rusting with its snow and ice control fleet, although we do normally experience some rusting due to the fact that the materials are in a concentrated form when we handle them. Staff has also not experienced an increase in rusting or wear on non- snow equipment and vehicles or their tire rims. The city fleet is washed as soon as possible following each storm event. According to a report on deicers done by Henry W. Kirchner P.E. consultant, "It appears that corrosion is most likely on unprotected (unpainted or non-sealed) iron, steel, and aluminum where moisture can be held against these exposed surfaces. Ordinarily, if the surfaces' paint, plating, or undercoating is not damaged or broken, corrosion will not occur when deicers are used in accordance with manufacturer recommendations." All of the products used in the city's snow and ice control program are water-soluble. VVheel rims and other aluminum or steel parts should be rinsed off periodically to help prevent any possible corrosion. If vehicle owners are concerned about corrosion (especially owners of vehicles with unpainted or non-sealed metal or already "pitted" metal) they should consider having tire rims or other exposed parts clear-coat sealed in order to help prevent corrosion. V g tation: Also according to the Kirchner report, "All deicers hold the potential for damaging grass and plant biota should their concentration within the soil become unusually high. Calcium, magnesium, and potassium can be beneficial to soil." Magnesium chloride is sold and used as a plant nutrient and a soil stabilizer. Ice Slicer consists of calcium, magnesium, sodium and potassium chlorides. Staff is unaware of any studies that have been done testing the effects of Ice $1iceron vegetation. However, the Air Force Academy staff in Colorado Springs says that it had to replace its grass and shrubs every year when using rock salt in its snow removal operations. Academy staff says it has not had to replace any vegetation since it started using Ice Slicer several years ago. Ice Ban is considered an "organic" deicer by the industry. According to the Levelton report, "There is no current published data on the environmental effects of using Ice Ban. However, it is not likely that this material would have any negative effect on vegetation, since it is produced from plant material." Transportation Maintenance staff has noticed what appears to be an effect of the deicers on evergreens. Since the materials started being used, staff has noticed more "burning" of this genus of plant and tree. It appears that the deicers can cause the evergreen needles/leaves to clog and stick together- reducing the amount of oxygen the plant can draw. Staff is not seeing the same effect on other plant life. VVhere we see most of the impact on vegetation is on major arterials that are high speed and high volume where splash up onto the medians and shoulders occurs. Staff has found that by trimming back the "burned" areas following each snow season, the evergreens are rejuvenated. Staff has also been looking into "flushing" the evergreens at the end of the snow season to help unclog the needles/leaves. Water Quality: City Water Quality staff has been monitoring the potential impacts of the deicers on the city's water quality for numerous years. Most recently, a study was done by Water Quality in 1998. The study found no significant impacts to water quality and aquatic life from the deicers. Water Quality will continue to evaluate and monitor water quality as materials continue to be used and as new materials are introduced. Numerous other studies have been done outside of the city regarding deicers and their impacts on water quality. Staff is unaware of any concerns of significance identified in these reports regarding the materials we use in our operations. New Products Being Tested: There are chloride-free liquid deicers on the market. These products are considered "organic" by the industry. However, their effectiveness is still being determined. These products are also extremely expensive. We are testing a liquid deicer this year called "NC3000." It is potassium acetate and contains no chlorides. However, it costs $2.50/gallon, 450 percent more than current liquid deicer costs per gallon. The product will be used sparingly until its effectiveness is determined. The product will also be used sparingly in order to stay within the appropriated materials budget. There is a new enhanced Ice Slicer product on the market called "Ice Slicer Elite." This product is treated with a corrosion inhibitor. Ice Slicer Elite passes PNSDOT standards with a corrosion rate of 30 (70 percent less corrosive than salt); however, it is significantly more expensive than Ice Slicer. Ice Slicer costs $59/ton and Ice Slicer Elite costs $138/ton. Staff believes that it might be able to "make" its own product by spraying the Ice $1icerwith Caliber (magnesium chloride and Ice Ban). There is a spray facility at the Municipal Service Center that can be used to create this new product. (In the past, the city used to spray its sand and gravel with the magnesium chloride in this spray facility). Staff will soon begin testing this process. Product Costs and Trade-offs: The city has been progressive in trying to use the best, most cost-effective materials to deal with snow and ice. The city has deliberately moved away from traction materials that do not melt and must be swept up. Traction materials that dissolve (crystallized deicers) help the city reduce PM10 and reduce sweeping costs for snow and ice. This allows the sweepers to be put to use on bike lanes and other high demand areas. Moving to new "alternative" materials is costly. "Freezgard" - the original magnesium chloride liquid deicer used by the city cost $.26/gallon. The deicer now being used, Caliber MIO00, costs $.56/gallon - doubling material costs. Chloride free deicers are very expensive - ranging from $2.50 - $4.00/gallon for liquid deicers and from $400 to $950/ton for crystallized deicers. For comparison, we currently pay $.56/gallon for liquid deicer and $59/ton for the crystallized deicer. The city uses on average 300,000 gallons of liquid deicer per year ($168,000) and on average 785 tons of crystallized traction material per year ($46,315) - for a total material cost of approximately $214,315/year. If the city were to move to the chloride free deicers it is anticipated that the material cost of the program will increase 500 percent or from $215,000/year to $1 million dollars per year. Staff has found that the price of materials comes down approximately 2-3 years after the product is introduced, and believes that the "chloride-free" products will be more reasonable within the next five years. 4 However, in the meantime, all of the products being used in the City's snow and ice control program meet industry standards for water quality, vegetation, and corrosion. Staff believes that the limited amount of potential damage to aluminum or other steel products does not justify a change in the products and a significant increase in product costs at this time. Direction: Unless otherwise directed by City Council, staff will continue to use the products identified above and continue to try new alternative products. Staff will continue to work toward finding a balance between cost and potential environmental impacts. If you have any questions or would like more information please contact Stephanie Grainger at 303-413-7118 or at .qrain.eers~ci.boulder.co.us ATTACHMENT E Public Works Maintenance Division Guidelines for Anti-icing/Deicing Introduction Public Works Maintenance Division (PWM) has established guidelines for the use of anti-icing and deicing agents as a tool to combat winter storms. The information contained herein is intended as a basic guideline only. This in no way constitutes a systematic process or procedure for the use of anti-icing/deicing materials, chemicals, or equipment. The successful use of anti-icing and deicing agents is a learning process through which knowledge, training and experience are gained. The use of anti-icing and deicing agents can be a very beneficial tool when used in conjunction with other best practices and methods for snow and ice control. PWM Anti-Icing/Deicing Guidelines 1. Guidance for Anti-Icing/Deicing Operations Guidance for anti-icing/deicing operations is presented in Tables 1-6 for six distinctive winter weather events. The six events are: 1. Light Snow Storm 2. Light Snow Storm with Period(s) of Moderate or Heavy Snow 3. Moderate or Heavy Snow Storm 4. Frost or Black Ice 5. Freezing Rain Storm 6. Sleet Storm The tables suggest the appropriate maintenance action to take during an initial or subsequent (follow-up) anti-icing/deicing operation for a given precipitation or icing event. Each action is defined for a range of pavement temperatures and an associated temperature trend. Application rates are suggested rates and should be adjusted if necessary to achieve effectiveness or efficiency, for local conditions. Comments and notes are given in each table where appropriate to further guide maintenance field personnel in their anti-icing/deicing operations. Included in the following charts are recommendations for the use of pre-wet aggregate. 2. Glossary of Terms: Anti-Icing: The application of liquid chemicals to prevent the formation of frost or the bonding of snow or ice to pavement. Initial application can be made either as a pretreatment in advance of freezing conditions and/or storm events. Black Ice: Popular term for a very thin coating of clear, bubble-free, homogenous ice which forms on a pavement with a temperature at or slightly above 32 F when the temperature of the air in contact with the ground is below the freezing-point of water and small slightly super cooled water droplets deposit on the surface and coalesce (flow together) before freezing. Deicing: The application of liquid chemicals which penetrate into, then accelerate the melting of already formed frost, ice or snow which is bonded to the road surface. Freezing Rain: Super cooled droplets of liquid precipitation falling on a surface whose temperature is below or slightly above freezing, resulting in a hard, slick, generally thick coating of ice commonly called glaze or clear ice. Non-super cooled raindrops falling on a surface whose temperature is well below freezing will also result in glaze. Frost: Also called hoarfrost. Ice crystals in the form of scales, needles, feathers or fans deposit on surfaces cooled by radiation or by other processes. The deposit may be composed of drops of dew frozen after deposition and of ice formed directly from water vapor at a temperature below 32 F (sublimation) Light Snow: Snow falling at the rate of less than lA in. per hour; visibility is not affected adversely. Liquid Chemical: A chemical solution; the volume of solution applied per lane mile is the chemical application rate used in this appendix. Calcium Magnesium Acetate (CMA): CMA is a biodegradable product made up of limestone and acetic acid (a compound of vinegar). CMA is normally applied in liquid form to lower the freezing point of water and to prevent it from turning to ice. Magnesium Chloride (as defined for ice control): Is a salt compound extracted primarily from the Great Salt Lake, with added rust inhibitors, used to prevent or remove the build up of ice and snow on roads Moderate andHeavy Snow: Snow falling at a rate of lA in. per hour or greater; visibility is significantly reduced. Pre-wet Aggregate: Liquid chemical applied to aggregate before it is placed on pavement. Sleet: A mixture of rain and snow, which has been partially melted by falling through an atmosphere with a temperature slightly above freezing. Slush: Accumulation of snow, which lies on an impervious base and is saturated with water in excess of its freely drained capacity. It will not support any weight when stepped or driven on but will "squish" until the base support is reached. 3. Winter Weather Event Tables Table 1. Weather Event: LIGHTSNOW Calcium Magnesium Acetate 25% Magnesium Chloride 27% Pre-wet Aggregate/Magnesium Chloride i~iti~ ~ ~ Mainte~ ction ~ Above 32 F, Dry, wet, ~ ~ *Monitor pavement temperature closely stead and slush or~ ~ *Treat icy patches if needed with rising light cover N/R N/R N/R ~ N/R N/R N/R CMA ~ 30-40/lm, MgC1 ~ 15-35/lm ory ' snow See See See ~ See See See ~ pre-wet aggregate comment comment comment ~ comment comment comment 32 F, Apply ~ Apply ~ ~ Reapply Reapply ~ *Application rates will depend on dilution or below is Dry 30-40/ 15-35/~ ~30-40/ ~15-35/~ potential imminent lm lm N/R ~ lm lm Apply ~ ~ plow- as plow- as ~ needed needed 25 to 32 F, Wet, slush, Apply ~ Apply ~ Plow- as ~ Reapply Reapply Plow- as ~ *Application rates will depend on dilution remaining in or light 40-50/ 20-40/ needed~ ~30-40/ ~20-40/ needed~ potential range snow cover lm lm and applym lm lm and apply ~ plow- as plow- as ~ needed needed 20 to 25 F, Wet, slush, N/R Apply ~ Plow- as ~ N/R Reapply Plow- as ~ *Application rates will depend on dilution remaining in or light plow- as 20-40/ needed ~ plow- as ~20-40/ needed ~ potential range snow cover needed lm and apply ~ needed lm and apply ~ *Do not apply CMA at this temperature ~ plow- as ~ range ~ needed 15 to 20 F, Dry, wet, N/R Apply ~ Plow- as ~ N/R Reapply Plow- as ~ *Application rates will depend on dilution remaining in slush, or plow- as 45-65/ needed~ plow- as ~45-65/ needed~ potential . range light cover needed lm and apply ~ needed lm and apply ~ *Do not apply CMA at th, s temperature snow ~ plow- as ~ range ~ needed Below 15 F, DW or N/R N/R Apply and ~ N/R N/R Plow- as ~ *Do not apply CMA or MgC1 at this stead or li ht snow plow- as plow' as plow' as ~ plow' as plow' as needed ~ temperature range Y g , · falling cover needed needed needed~ needed needed and apply~ Apply pre-wet abrasives only CHEMICAL APPLICATIONS: These application rates are starting points. Local experience should refine these recommendations. Time chemical applications to prevent deteriorating conditions or development of packed and bonded snow-. Monitor temperature and humidity to determine application timing. PLOWING: Before applying any ice control chemical, the road surf:ace should be clear of as much snow- and ice as possible. CHEMICAL RATES: The recommended snow- and ice control material application rates depend on atmospheric and pavement conditions at the time of treatment and on how- these conditions are expected to change over the time period (window) between the current treatment and the next anticipated treatment. Table 2. Weather Event: LIGHT SNOW STORM WITH PERIOD(S) OF MODERATE OR HEAVY SNOW Calcium Magnesium Acetate 25% Magnesium Chloride 27% Pre-wet Aggregate/Magnesium Chloride nt nt nt i~itiaJ Mai~ ~ ction Dot Above 32 F, Dry, wet, *Monitor pavement temperature closely steady and slush, or N/R N/R N/R N/R N/R N/R *Treat icy patches if needed with See See See See See See CMA ~ 30-40/lm, MgC1 ~ 15-35/lm or rising light cover comment comment comment comment comment comment pre-wet aggregate snow 32 F, Apply ~ Apply ~ Reapply Reapply *Application rates will depend on dilution or below is Dry 30-40/ 15-35/ N/R ~30-40/ ~15-35/ N/R potential imminent lm lm lm lm 25 to 32 F, Wet, slush, Apply ~ Apply ~ Plow- as Reapply Reapply Plow- as *Application rates will depend on dilution remaining in or light 40-50/ 20-40/ needed ~40-50/ ~20-40/ needed potential lm lm and apply lm lm and apply range snow cover plow- as plow- as plow- as plow- as needed needed needed needed 20 to 25 F, Wet, slush, N/R Apply ~ Plow- as N/R Reapply Plow- as *Application rates will depend on dilution remaining in or light plow- as 20-40/ needed plow- as ~20-40/ needed potential needed lm and apply needed lm and apply *Do not apply CMA at this temperature range snow cover plow- as plow- as range needed needed 15 to 20 F, Dry, wet, N/R Apply ~ Plow- as N/R Reapply Plow- as *Application rates will depend on dilution remaining in slush, or plow- as 45-70/ needed plow- as ~45-70/ needed potential range light cover needed lm and apply needed lm and apply *Do not apply CMA at this temperature plow- as range snow needed Below 15 F, Dry or N/R N/R Apply and N/R N/R Plow- as *Do not apply CMA or MgC1 at this steady or light snow plow- as plow' as plow' as plow' as plow' as needed temperature range needed needed needed needed needed and apply *Apply pre-wet abrasives only falling cover CHEMICAL APPLICATIONS: These application rates are starting points. Local experience should refine these recommendations. Time chemical applications to prevent deteriorating conditions or development of packed and bonded snow-. Monitor temperature and humidity to determine application timing. PLOWING: Before applying any ice control chemical, the road surf:ace should be clear of as much snow- and ice as possible. CHEMICAL RATES: The recommended snow- and ice control material application rates depend on atmospheric and pavement conditions at the time of treatment and on how- these conditions are expected to change over the time period (window) between the current treatment and the next anticipated treatment. Table 3. Weather Event: MODERATE OR HEA FT SNOWSTORM Calcium Magnesium Acetate 25% Magnesium Chloride 27% Pre-wet Aggregate/Magnesium Chloride cao Above 32 ~, DW, wet, *Monitor pavement temperature closely steady and slush, or *Treat icy patches if needed with rising light cover N/R N/R N/R N/R N/R N/R CMA ~ 30-40/lm or snow MgC1 ~ 15-35/lm 32 F, Apply ~ Apply ~ Reapply Reapply *Application rates will depend on dilution or below is Dry 30-40/ 15-35/ N/R ~30-40/ ~15-35/ potential imminent lm lm lm lm N/R *Do not apply CMA or MgC1 on heavy snow- accumulation or snow- pack 25 to 32 F, Wet, slush, N/R N/R Plow- as N/R N/R Plow- as *Do not apply CMA or MgC1 on heavy remaining in or light plow- as plow' as needed plow- as plow- as needed snow- accumulation or snow- pack range snow cover needed needed and apply needed needed and apply *Apply pre-wet abrasives only 20 to 25 F, Wet, slush, N/R N/R Plow- as N/R N/R Plow- as *Do not apply CMA or MgC1 on heavy remaining in or light plow- as plow' as needed plow- as plow- as needed snow- accumulation or snow- pack range snow cover needed needed and apply needed needed and apply *Apply pre-wet abrasives only 15 to 20 F, Dry, wet, N/R N/R Plow- as N/R N/R Plow- as remaining in slush, or plow- as plow' as needed plow- as plow- as needed *Do not apply CMA or MgC1 on heavy range light cover needed needed and apply needed needed and apply snow- accumulation or snow- pack snow *Apply pre-wet abrasives only Below 15 F, Dry or N/R N/R Plow- as N/R N/R Plow- as *Do not apply CMA or MgC1 at this steady or light snow plow- as plow' as needed plow- as plow- as needed temperature range falling cover needed needed and apply needed needed and apply *Apply pre-wet abrasives only CHEMICAL APPLICATIONS: These application rates are starting points. Local experience should refine these recommendations. Time chemical applications to prevent deteriorating conditions or development of packed and bonded snow-. Monitor temperature and humidity to determine application timing. PLOWING: Before applying any ice control chemical, the road surf:ace should be clear of as much snow- and ice as possible. CHEMICAL RATES: The recommended snow- and ice control material application rates depend on atmospheric and pavement conditions at the time of treatment and on how- these conditions are expected to change over the time period (window) between the current treatment and the next anticipated treatment. Table 4. Weather Event: FROST OR BLACKICE Calcium Magnesium Acetate 25% Magnesium Chloride 27% Pre-wet Aggregate/Magnesium Chloride ~ ~ Mainte~ ction ~ Above 32 F, *Monitor pavement temperature closely steady and Any level *Treat icy patches if needed with rising N/R N/R N/R N/R N/R N/R CMA ~ 30-40/lm or MgC1 (~ 15-35/lm 28 to 32 F, Apply ~ Apply ~ Reapply Reapply Remaining in < 100 20-30/ 15-30/ ~20-30/ ~15-30/ range or falling vehicles/hr lm lm lm lm 32 F or below, and equal to or Apply ~ Apply ~ Apply Reapply Reapply Reapply *Application rates will depend on dilution below dew > 100 30-40/ 20-35/ ~30-40/ ~20-35/ potential point vehicles/hr lm lm lm lm 25 to 28 F, remaining in Apply ~ Apply ~ Reapply Reapply range, a~d Any level 30-40/ 20-35/ Apply ~30-40/ ~20-35/ Reapply *Application rates will depend on dilution equal to or lm lm lm lm potential below dew point 15 to 25 F, remaining in *Application rates will depend on dilution Range, and Any level N/R Apply ~ Apply N/R Reapply Reapply potential equal to or 25-40/ ~25-40/ *Do not apply CMA at this temperature below dew lm lm range point Below 15 F, Any level N/R N/R Apply N/R N/R Reapply *Do not apply CMA or MgC1 at this Steady or temperature range falling Below 15 F, Dry or N/R N/R Apply and N/R N/R Plow- as *Do not apply CMA or MgC1 at this steady or light snow plow- as plow' as plow' as plow' as plow' as needed temperature range falling cover needed needed needed needed needed and apply *Apply pre-wet abrasives only CHEMICAL APPLICATIONS: These application rates are starting points. Local experience should refine these recommendations. Time chemical applications to prevent deteriorating conditions or development of packed and bonded snow-. Monitor temperature and humidity to determine application timing. PLOWING: Before applying any ice control chemical, the road surf:ace should be clear of as much snow- and ice as possible. CHEMICAL RATES: The recommended snow- and ice control material application rates depend on atmospheric and pavement conditions at the time of treatment and on how- these conditions are expected to change over the time period (window) between the current treatment and the next anticipated treatment. Table 5. Weather Event: FREEZING RAINSTORM Calcium Magnesium Acetate 25% Magnesium Chloride 27% Pre-wet Aggregate/Magnesium Chloride ~isl is/ ~ isl is/ Above 32 F, *Monitor pavement temperature closely steady and N/R N/R See N/R N/R See *Treat icy patches if needed w-ith pre-wet rising comments comments aggregate as needed for traction enhancement 32 F, or below is N/R N/R Apply N/R N/R Reapply *Apply pre-wet aggregate for traction imminent enhancement 20 to 32 F, remaining in N/R N/R Apply N/R N/R Reapply *Apply pre-wet aggregate for traction range enhancement 15 to 20 F, remaining in N/R N/R Apply N/R N/R Reapply *Apply pre-wet aggregate for traction range enhancement Below 15 F, steady or N/R N/R Apply N/R N/R Reapply *Apply pre-wet aggregate for traction falling enhancement CHEMICAL APPLICATIONS: These application rates are starting points. Local experience should refine these recommendations. Time chemical applications to prevent deteriorating conditions or development of packed and bonded snow-. Monitor temperature and humidity to determine application timing. PLOWING: Before applying any ice control chemical, the road surf:ace should be clear of as much snow- and ice as possible. CHEMICAL RATES: The recommended snow- and ice control material application rates depend on atmospheric and pavement conditions at the time of treatment and on how- these conditions are expected to change over the time period (window) between the current treatment and the next anticipated treatment. Table 6. Weather Event: SLEETSTORM Calcium Magnesium Acetate 25% Magnesium Chloride 27% Pre-wet Aggregate/Magnesium Chloride ~ai~ ~ ~ct~ ~ Mainte~ ction ~ is/i Above 32 F, *Monitor pavement temperature closely steady and N/R N/R See N/R N/R See for drops towards 32 F rising comments comments *Treat icy patches if needed with pre-wet aggregate as needed for traction enhancement 32 F, N/R N/R N/R N/R Reapply *Apply pre-wet aggregate for traction as needed enhancement or below is Apply and plow imminent accumula- tion 20 to 32 F, N/R N/R Apply N/R N/R Reapply *Apply pre-wet aggregate for traction remaining in as needed enhancement range and plow accumula- tion 15 to 20 F, N/R N/R Apply N/R N/R Reapply *Apply pre-wet aggregate for traction remaining in as needed enhancement range and plow accumula- tion Reapply Below 15 F, N/R N/R Apply N/R N/R as needed *Apply pre-wet aggregate for traction steady or and plow- enhancement falling accumula- tion CHEMICAL APPLICATIONS: These application rates are starting points. Local experience should refine these recommendations. Time chemical applications to prevent deteriorating conditions or development of packed and bonded snow-. Monitor temperature and humidity to determine application timing. PLOWING: Before applying any ice control chemical, the road surfhce should be clear of as much snow- and ice as possible. CHEMICAL RATES: The recommended snow- and ice control material application rates depend on atmospheric and pavement conditions at the time of treatment and on how- these conditions are expected to change over the time period (window) between the current treatment and the next anticipated treatment. 4. General Guidelines to Anti-icing/Deicing Operations The following list outlines basic decision making criteria, and lists some of the basic operational functions to consider and/or follow when applying chemical anti- icing/deicing agents or abrasives. Weather factors: · Do not apply chemicals prior to forecasted rain · Do not apply chemicals if temperatures are above 32 F and steady · Do not apply chemicals in strong winds · Do not apply chemicals if rain is predicted before a snow storm · Use caution when anti-icing/deicing in warm conditions with low humidity as a chemical slipperiness condition may occur especially using heavier application rates · Do not apply CMA on a heavy snow or ice packs · Do not apply CMA in temperatures below 25 F. · Apply only abrasives in temperatures below 15 F · Residual effects can remain for up to several days after application of chemicals if precipitation does not dilute the initial application. Refreezing of the surface can occur when precipitation or moisture in the air dilutes the chemical on the surface Operational considerations: · Always record time, location and rate of chemicals and abrasive application · Do not over apply chemicals within an intersection. · Avoid applying chemicals in heavy traffic. Application of anti- icing/deicing agents should be done if possible during slow commuting hours · Allows check spray operations prior to leaving Roosevelt facility · More is not always BETTER. High application rates can cause slippery conditions