Road Salt

The abundant natural resources of the Adirondack Park, positioned in a setting of interspersed public and private ownerships and multiple jurisdictional layers of management, make for a place in which the competing interests of human use and enjoyment of the landscape and protection of its resources can create significant challenges. It is also a place where there is a critical role for applied science in informing policy and management decisions. Here we describe four examples in which applied science, combined with education and outreach, have been used to inform management responses to critical threats impacting the Adirondack landscape. This paper describes the work of two organizations who have invested heavily in the region, using place-based and collaborative approaches to inform important policy issues. We describe each as a case study and draw conclusions across all of them that provide useful lessons for conservation in the region.

The abundant natural resources of the Adirondack Park, positioned in a setting of interspersed public and private ownerships and multiple jurisdictional layers of management, make for a place in which the competing interests of human use and enjoyment of the landscape and protection of its resources can create significant challenges. It is also a place where there is a critical role for applied science in informing policy and management decisions. Here we describe four examples in which applied science, combined with education and outreach, have been used to inform management responses to critical threats impacting the Adirondack landscape. This paper describes the work of two organizations who have invested heavily in the region, using place-based and collaborative approaches to inform important policy issues. We describe each as a case study and draw conclusions across all of them that provide useful lessons for conservation in the region.

The abundant natural resources of the Adirondack Park, positioned in a setting of interspersed public and private ownerships and multiple jurisdictional layers of management, make for a place in which the competing interests of human use and enjoyment of the landscape and protection of its resources can create significant challenges. It is also a place where there is a critical role for applied science in informing policy and management decisions. Here we describe four examples in which applied science, combined with education and outreach, have been used to inform management responses to critical threats impacting the Adirondack landscape. This paper describes the work of two organizations who have invested heavily in the region, using place-based and collaborative approaches to inform important policy issues. We describe each as a case study and draw conclusions across all of them that provide useful lessons for conservation in the region.

As chemicals are widely used for snow and ice control of highway and airfield pavements or aircrafts, recent years have seen increased concerns over their potentially detrimental effects on the surrounding environment. The abrasives used for winter operations on pavements are also a cause of environmental concerns. After some background information, this paper presents a review of the environmental impacts of chemicals used for snow and ice control, including those on: surface, ground, and drinking waters; soil; flora; and fauna. The paper provides a state-of-the-art survey of published work (with a focus on those in the last two decades) and examines mainly the impacts of abrasives, chlorides, acetates and formates, urea, glycols, and agro-based deicers. Finally, we conclude with a brief discussion of public perception of such impacts and best management practices (BMPs) to mitigate them.

Abstract: This document is a final report of the project Winter Impacts along Cascade Lakes in the Adirondacks (C-03-06), funded by the New York State Department of Transportation (NYSDOT). The Technical Working Group over-seeing this project included representatives from several NYSDOT units, the New York State Department of Environmental Conservation, and the Adirondack Park Agency. This research project was conducted at two sites along New York State Route 73 in Essex County, New York State: Upper and Lower Cascade ...

Laboratory snow melting experiments were conducted with actual late-winter snow samples, collected just before the final snowmelt, in two similar northern Swedish cities, Luleå and Umeå, to investigate releases of the selected heavy metals (HM) (Cu, Pb, Zn, and Cd) and 16 USEPA PAHs from melting snow. Metal concentrations were determined in three fractions: total, dissolved, and truly dissolved (defined as the fraction passing through a 3-kMWCO ultrafilter). Total HM concentrations in snowmelt were rather high at both sites and reflected the accumulation of pollutants in the roadside snowbanks over a period of about 5 months: Cd = 0.43, Cu = 303, Pb = 41.9, Zn = 817 (μg/l), and TSS = 2000 (mg/l) in Luleå samples and Cd = 1.87, Cu = 905, Pb = 165, Zn = 3150 (μg/l), and TSS = 4800 (mg/l) in Umeå samples. The difference between metal and TSS concentrations at the two sites of similar characteristics was attributed to a smaller volume snowbank in Umeå. The dissolved HM concentrations represented relatively small fractions of the total concentrations (0.3-6.9% in Luleå and 0.01-3.1% in Umeå). The truly dissolved fraction represented 71-90% of the dissolved fraction in Luleå and 74-98% in Umeå. At both sites, the dissolved fractions exhibited preferential elution from the laboratory snow piles. The PAHs studied (16 US EPA PAHs) were mostly particulate bound, with only 5-12% of the total burden contributed by the meltwater, and most dissolved concentrations below the reporting limits. PAH concentrations in the Luleå samples were about one-third to one-fourth of those in Umeå. In general, the releases of PAHs from the snowbank were delayed, compared with releases of meltwater, and showed similar release patterns as TSS.

The need for winter road maintenance (WRM) is changing in cold regions due to climate change. How the different modes of WRM will contribute to future overall emissions from infrastructure is therefore of great interest to road owners with a view to a more sustainable, low-carbon future. In the quest for near-zero-emissions transport, all aspects of the transport sector need to be accounted for in the search for possible mitigation of emissions. This study used 35 peer-reviewed articles published between 2000 and 2018 to map available information on the environmental impacts and effect of WRM and reveal any research gaps. The articles were categorized according to their research theme and focus. They were found to focus mainly on the local effects of WRM with emphasis on effects on water. Of the reviewed works, 27 contain information related to the environmental effects of deicers on a local level while five focused on global impact, which was mainly caused by fuel consumption. Only two articles took a holistic look at the system to identify emission sources and the effectiveness of possible changes in operations methods or material selection. In conclusion, WRM would benefit from further research to understand how it affects the natural environment in regions with a cold climate. Furthermore, a life-cycle approach could reveal ways to mitigate emissions through effectively comparing possible changes in the system without shifting the problem to other aspects of road transport.

Saline melt water from road salt applications that has percolated into a fine sandy soil in winter is rinsed out of the soil by infiltrating rainwater in the following warmer seasons. This sequence of saturated and unsaturated flow processes associated with saline water transport in a fine sandy soil was studied by simulation and exploratory laboratory experiments. Experiments in soil columns of 300-μm sand revealed that two rinses of pure water, each of one pore volume, were sufficient to reduce the salt concentration by 99% of its original value in the soil column. Simulated time variations of salt concentration in the effluent from the column agreed with experimental results. Based on simulated and experimental results, a sandy soil must become saturated to experience pore water flow in order to efficiently rinse saline snowmelt water. Depending on the saturated hydraulic conductivity and the soil depth, days, weeks, or months of freshwater infiltration in summer are needed to rinse saline melt water from an unsaturated sandy soil after road salt applications in winter. This explains findings of significant salt concentrations in surface and shallow groundwater during summer months, long after road salt application and infiltration has ceased.

Saline melt water from road salt applications that has percolated into a fine sandy soil in winter is rinsed out of the soil by infiltrating rainwater in the following warmer seasons. This sequence of saturated and unsaturated flow processes associated with saline water transport in a fine sandy soil was studied by simulation and exploratory laboratory experiments. Experiments in soil columns of 300-μm sand revealed that two rinses of pure water, each of one pore volume, were sufficient to reduce the salt concentration by 99% of its original value in the soil column. Simulated time variations of salt concentration in the effluent from the column agreed with experimental results. Based on simulated and experimental results, a sandy soil must become saturated to experience pore water flow in order to efficiently rinse saline snowmelt water. Depending on the saturated hydraulic conductivity and the soil depth, days, weeks, or months of freshwater infiltration in summer are needed to rinse saline melt water from an unsaturated sandy soil after road salt applications in winter. This explains findings of significant salt concentrations in surface and shallow groundwater during summer months, long after road salt application and infiltration has ceased.

The abundant natural resources of the Adirondack Park, positioned in a setting of interspersed public and private ownerships and multiple jurisdictional layers of management, make for a place in which the competing interests of human use and enjoyment of the landscape and protection of its resources can create significant challenges. It is also a place where there is a critical role for applied science in informing policy and management decisions. Here we describe four examples in which applied science, combined with education and outreach, have been used to inform management responses to critical threats impacting the Adirondack landscape. This paper describes the work of two organizations who have invested heavily in the region, using place-based and collaborative approaches to inform important policy issues. We describe each as a case study and draw conclusions across all of them that provide useful lessons for conservation in the region. 60 THE A DI RON DACK JOURNA L OF ENVIRONMENTAL STUDIES

Road salt deicing started in the United States during the 1940s and is still commonly used today (Glancy & Hinkle, 1986, p.1). The consequences of using road salt on infrastructure and the environment were discovered in the 1970s, and in 1976 the Environmental Protection Agency completed its first assessments on road salt. The results lead the Federal Highway Administration to seek an alternative to road salt (Glancy & Hinkle, 1986, p.1). This project shares the results of various studies that support calcium magnesium acetate as a noteworthy alternative to road salt. Several alternative deicers are analyzed. Based on several variables, calcium magnesium acetate is an environmentally friendly alternative. An implementation plan was devised for calcium magnesium acetate given the results of several studies. help road salt stick to the road and reduce the amount used. Machinery costs, inconsistency in effectiveness, and continued use of chloride are substantial reasons the brine solut...

The Indiana Department of Transportation (INDOT) spends approximately $30 to $60 million a year on deicing salt and operates a fleet of 1,000 winter operations trucks distributed among 140 locations. The entire fleet is now instrumented with location telematics, and all new trucks have integrated dash cameras, salt spreader application rate and plow up/plow down integrated into the telematics link. When winter storms occur, they have varying regional impacts and INDOT monitors several data sources including National Weather Service (NWS) live doppler, National Severe Storms Laboratory's (NSSL) Multi-Radar Multi-Sensor (MRMS) products, road weather monitoring stations, and connected vehicles (CV) that provide roadway segment operating speeds. This paper discusses how telematics has been integrated to provide a comprehensive view of conditions, truck asset locations, and material distribution maps. The telematics identified widely varying salt spreader rates for the same calibration settings and equipment in preliminary analysis. A calibration box is developed to allow offload calibration to occur within 10 minutes without weighing or transporting the fleet vehicle. The method is deployed across six districts at INDOT for over 1000 snowplows. A sampling of eight trucks in the fleet found the proposed calibration method reduced salt application on average of 45%. This paper describes a series of telematics dashboards for managing winter operations and details the methods developed for 140 geographically distributed truck units to conduct simple, fast, and effective calibration.

Table. 1 Data set information Title of data set Supporting dataset for chloride source delineation in an urban-agricultural watershed, deicing agents versus agricultural contributions Abstract Analyses (n = 535) of chloride (Cl-), bromide (Br-), nitrate as nitrogen (NO3-N), sodium (Na +), calcium (Ca 2+), and potassium (K +) in stream water, tile-drain water, and groundwater were conducted in an urban-agricultural watershed (10% urban/impervious, 87% agriculture) to explore potential differences in the signature of Cloriginating from an urban source as compared to an agricultural source. Water samples were collected on a weekly interval from February 2018 to February 2019 at three station along the stream and from tile drains and wells. Nearly all surface water and tile water samples had Clconcentrations above the calculated background threshold of 18 mg/l. Mann-Whitney U test revealed ratios of Clto Br-(p = 0.045), NO 3-N (p < 0.0001), Ca 2+ (p < 0.0001), and Na + (p < 0.0001) to be statistically significantly different between urban and agricultural waters. Cl-ratios indicate that road salt is the dominant source of Cl-in the watershed, while potassium chloride fertilizer is an important secondary source. This study demonstrated that while deicing in watersheds where urban land use is minimal can have a profound impact on Cldynamics, agricultural practices should not be ignored.

This study examined the effects of increased salinity on growth, development and survival of the Green toad, Bufotes variabilis during embryonic, hatching and early larval periods. Eggs from a single cohort of B. variabilis were subjected to acute and chronic toxicity tests for water salinity ranging from 0.20 to 10 g of salt per liter. Results obtained from this study showed that salinity over 3.70 g/l increased embryonic mortality and reduced percentage of hatching and survival rate of larvae. As larvae tolerated salinity 0.20 to 3.70 g/l with highest survival, but salinity of 10 g/l caused mortality of all individuals within 12 h, 7.70–8.70 (g/l) within 4.5 days, 5.70–6.70 g/l within 10 days and 4.70 (g/l) were tolerated within 14 days. Salinity less than 0.70 g/l did not affect survival and hatching success of the embryos. After a 3-week experiment, size of larvae exposed to salinities over 0.70 g/l was lower compared to larvae reared at lower salinity levels. Meanwhile increase...

Saline melt water from road salt applications that has percolated into a fine sandy soil in winter is rinsed out of the soil by infiltrating rainwater in the following warmer seasons. This sequence of saturated and unsaturated flow processes associated with saline water transport in a fine sandy soil was studied by simulation and exploratory laboratory experiments. Experiments in soil columns of 300-μm sand revealed that two rinses of pure water, each of one pore volume, were sufficient to reduce the salt concentration by 99% of its original value in the soil column. Simulated time variations of salt concentration in the effluent from the column agreed with experimental results. Based on simulated and experimental results, a sandy soil must become saturated to experience pore water flow in order to efficiently rinse saline snowmelt water. Depending on the saturated hydraulic conductivity and the soil depth, days, weeks, or months of freshwater infiltration in summer are needed to rinse saline melt water from an unsaturated sandy soil after road salt applications in winter. This explains findings of significant salt concentrations in surface and shallow groundwater during summer months, long after road salt application and infiltration has ceased.

This paper describes the design, calibration and testing processes of a new device named Automated Laboratory Infiltrometer (ALI). It allows to determinate in laboratory, under controlled conditions the saturated hydraulic conductivity (Ks) of altered or unaltered soil samples which is a key parameter to understand the movement of water through a porous medium. The ALI combines the advantages of three different approaches: measures vertical infiltration rates in a soil column, measures the actual volumes of vertically drained water through the soil column, and finally, uses heat as a natural tracer to determinate water flux rates through the porous medium; all those parameters are used to determinate Ks. The ALI was developed using the popular Arduino microcontroller board and commercially available sensors that give the whole system a low cost. Data from the ALI are recorded in a microSD memory so they can be easily read from any spreadsheet software helping to reduce time consumin...

Mike Borst for their efforts to make this the best possible document. We would also like to thank Mr. Nanda Srinivasan for his coordination and management of this project. A special thank you goes to Mr. Scott Jungwirth, Mr. Stephen Mery, and Mr. Yongxin Li for their efforts researching and writing sections of this report. And a final thank you to Ms. Marie Venner of Venner Consulting and Mr. Eric Strecker of Geosyntech Consultants for their efforts.

There are increasing concerns regarding the adverse environmental impacts of chloride from road salts. A web-based survey was conducted to determine how the Code of Practice for the environmental management of road salts has influenced the adoption of best practices in Ontario, Canada. The majority of large Ontario municipalities have salt management plans that adequately address safety and the environment. Most municipalities train a high percentage of permanent staff but only half of seasonal workers and 21% of private contractors are trained. Most training programs cover key learning goals defined by the Code of Practice. There is little improvement in the management of salt-vulnerable areas. Many existing snow disposal sites are poorly designed and do not manage snowmelt quality. The Code has strongly contributed to the adoption and improvement of salt management practices in Ontario by helping to standardize practices and advance the rate of implementation of best practices. Barriers to further implementation of the Code include understanding the Code, institutional will, liability, limited technical/financial resources and public expectation of high service levels. Further benefits can be achieved by aggressively promoting the Code and improving education and training programs for the public, private contractors and staff of road authorities.

The performance and impacts of several bio-based anti-icers along with a traditional chloride-based anti-icer (salt brine) were evaluated. A statistical design of experiments (uniform design) was employed for developing anti-icing liquids consisting of cost-competitive chemicals such as bio-based compounds (e.g., sugar beet extract and dandelion extract), rock salt, sodium metasilicate, and sodium formate. The following experimentally obtained parameters were examined as a function of the formulation design: ice-melting capacity and ice penetration at 25°F (−3.9°C) and 15°F (−9.4°C), compressive strength of Portland cement mortar samples after 10 freeze-thaw/deicer cycles, corrosion rate of C1010 carbon steel after 24-hour immersion, and impact on asphalt binder’s stiffness. One viable formula (“best performer”) was tested for freezing point depression phase diagram (ASTM D1177-88) and the friction coefficient of asphalt pavement treated by this anti-icing formulation (vs. 23 wt.% N...

Agriculturally derived products, or agro-based products, and complex chloride mineral (CCM) based products are increasingly employed in snow and ice control operations, either used alone or more commonly as additives or blended with traditional chloride-based products such as rock salt (solid sodium chloride) and salt brine (liquid sodium chloride). Past studies and manufacturers have claimed that agro-based or CCM based products provide benefits such as freezing point depression, prolong performance on the road surface, the ability to utilize UV light as an aid to ice prevention, and various environmental benefits. However, the measurement of the effectiveness of such products has been limited. To further investigate the role CCM and agro-based products may have in deicing and corrosion protection, a literature review and national survey were conducted to identify potential products, how they are typically used, performance characteristics, and pros and cons. Ten products were sele...

Winter roadway operations, commonly known as snow/ice control operations, are one of the most critical functions of state, provincial and local transportation agencies in cold regions. These operations aim to provide safety and mobility by timely and effective application of materials and plowing. The most common materials used are salt (sodium chloride, solid and brine), magnesium chloride-based, and calcium chloride-based deicers, agro-based additives and blends, and abrasives, with the specific choice and application method and rate dependent on temperature, precipitation type, level of service goals, budget, and environmental sustainability. Best practices of material application are designed to apply the right type and amount of materials in the right place at the right time. A companion document to this report, the "Material Application Methodologies Guidebook," synthesizes the use of materials, including application strategies, application rates, and application equipment. This report documents the literature review and agency interviews that were conducted to assemble the information for the Guidebook.

Winter roadway operations, commonly known as snow and ice control operations, are one of the most critical functions of state, provincial, and local transportation agencies in cold regions. These operations aim to provide safety and mobility through the timely and effective application of materials and mechanical removal. The most common materials used are salt (sodium chloride, solid or liquid brine), magnesium chloride-based, calcium chloride-based deicers, agro-based additives and blends, and abrasives. In practice, the specific choice and application method and rate of these materials are dependent on pavement temperature, precipitation type, level of service goals, budget, and environmental sustainability considerations. Best practices of material application are designed to apply the right type and amount of materials in the right place at the right time. This review presents a literature review and agency interviews that were conducted to gather information about the use of m...

The traditional use of the sand-salt mix for highway traction and safety enhancement in winter has resulted in severe problems of particulate matter in the air. The Colorado Department of Transportation (CDOT) has implemented its new winter roadway maintenance policy, which involves the increasing use of deicing chemicals and decreasing use of sand and sand-rock salt mix. This study addresses the cost impact of the new policy to the CDOT winter roadway maintenance practice and the general and traveling public. In the midst of the fastest population growth in the last decade, the CDOT new winter roadway maintenance policy has shown to benefit CDOT in the enhancement of its public image and appreciation and the winter roadway maintenance cost reduction, the traveling public in the reduction of insurance cost and the enhancement of highway safety, and the general public in the improvement of air quality.

Agriculturally derived products, or agro-based products, and complex chloride mineral (CCM) based products are increasingly employed in snow and ice control operations, either used alone or more commonly as additives or blended with traditional chloride-based products such as rock salt (solid sodium chloride) and salt brine (liquid sodium chloride). Past studies and manufacturers have claimed that agro-based or CCM based products provide benefits such as freezing point depression, prolong performance on the road surface, the ability to utilize UV light as an aid to ice prevention, and various environmental benefits. However, the measurement of the effectiveness of such products has been limited. To further investigate the role CCM and agro-based products may have in deicing and corrosion protection, a literature review and national survey were conducted to identify potential products, how they are typically used, performance characteristics, and pros and cons. Ten products were sele...

This project sought to document patterns of road deicing salts and the effects of these salts on the amount of carbon being sequestered passively along Montana Department of Transportation roads; it was designed collaboratively with a related roadside project that tested three different highway right-of-way management techniques (mowing height, shrub planting, disturbance) to determine whether they have the capacity to increase soil organic carbon. Our sampling did not reveal elevated salt levels at any of the nine locations sampled at each of the three I-90 sites. The greatest saline concentrations were found at the sample locations farthest from the road. This pattern was consistent across all three sites. The range of soil organic matter (SOM) was broad, from ~1% to >10%. Generally, SOM values were lowest adjacent to the road and highest farthest from the road. We found no or weak evidence of a relationship between our indices of soil salinity and SOM levels, with electrical conductivity, exchangeable calcium, and cation exchange capacity. Results imply that if road deicing salts are altering patterns of roadside SOM and potential carbon sequestration, this effect was not captured by our experimental design, nor did deicing salts appear to have affected roadside vegetation during our most recent sampling effort. Our findings highlight the value of experimentally separating the multiple potentially confounding effects of winter maintenance operations on roadside soils: roads could focus the flow of water, salts, and sands to roadside soils. How these types of mass inputs to roadside soils might influence medium-or long-term carbon dynamics remains an open question, but their fuller characterization and possible flow paths will be essential to clarifying the role of roadside soils in terrestrial soil organic carbon sequestration strategies.

As much as 40% of salt use in some areas is from private users. Salt is not only used on public roads, but on parking lots and internal roads of commercial and industrial establishments, schools, churches and other nonprofit institutions, apartment complexes and other residences, and by individual home and small business owners. Education about ways to improve efficiency among private contractors can go a long way toward reducing salt loadings to the environment. Highway superintendents should share educational materials and training and maintain open lines of communication with private salt users. Remember that the end result is cleaner surface water and groundwater, so it's for the public good. There's the added benefit of direct cost savings in using less salt. Some insurance companies may reduce liability rates if workers are trained in efficiently maintaining ice-free travelling surfaces. Municipalities can offer a certification program for sidewalk and parking lot contractors. Minnesota is the first state to offer this, but it should extend to other states. Public awareness campaign Every year at the onset of winter drivers should be informed about snow ordinances and safe driving habits in written communications or workshops.

Increased application of chemical deicers for winter maintenance has resulted in increased concentrations of deicer constituents in the environment. The runoffs from the deicing operation have a deteriorating effect on soil and water quality. But the degree of impact is localized and it depends on various climatic factors and can also be attributed to the type of salts used and their storage conditions. This paper presents a review of the environmental impact of deicing chemicals.

Increased application of chemical deicers for winter maintenance has resulted in increased concentrations of deicer constituents in the environment. The runoffs from the deicing operation have a deteriorating effect on soil and water quality. But the degree of impact is localized and it depends on various climatic factors and can also be attributed to the type of salts used and

The present study aims at modelling of soil moisture movement in Barchi watershed (Karnataka) using SWIM (Soil Water Infiltration and Movement). Field and laboratory investigations were carried out to determine the saturated hydraulic conductivity at eight locations using Guelph Permeameter and soil moisture retention characteristics using the Pressure Plate Apparatus. The van Genuchten parameters of soil moisture retention function and hydraulic conductivity function were obtained through non-linear regression analysis. Daily rainfall and evaporation data of Barchi for the period 1996-1997 to 1999-2000 were used for the simulations. Water balance components like runoff, evapotranspiration and drainage (groundwater recharge from rainfall) were determined through SWIM. The drainage was found to vary between 38% and 47% of rainfall (1241 mm to 1887 mm) while the runoff coefficient varied between 12% and 32% for the study period.

The general goal of this project was to assess the magnitude of environmental problems associated with winter road management (ie chemical deicer and abrasive applications) at these sites, and to make appropriate recommendations on how to ameliorate environmental impacts of winter road management (Note: Throughout the report, we will use the standard term chemical diecer, recognizing that materials may be used in pre-storm anti-icing (as is the normal practice at the Cascade Lakes), or for true deicing after precipitationsnow and ...

Saline melt water from road salt applications that has percolated into a fine sandy soil in winter is rinsed out of the soil by infiltrating rainwater in the following warmer seasons. This sequence of saturated and unsaturated flow processes associated with saline water transport in a fine sandy soil was studied by simulation and exploratory laboratory experiments. Experiments in soil columns of 300-μm sand revealed that two rinses of pure water, each of one pore volume, were sufficient to reduce the salt concentration by 99% of its original value in the soil column. Simulated time variations of salt concentration in the effluent from the column agreed with experimental results. Based on simulated and experimental results, a sandy soil must become saturated to experience pore water flow in order to efficiently rinse saline snowmelt water. Depending on the saturated hydraulic conductivity and the soil depth, days, weeks, or months of freshwater infiltration in summer are needed to rinse saline melt water from an unsaturated sandy soil after road salt applications in winter. This explains findings of significant salt concentrations in surface and shallow groundwater during summer months, long after road salt application and infiltration has ceased.

The general goal of this project was to assess the magnitude of environmental problems associated with winter road management (ie chemical deicer and abrasive applications) at these sites, and to make appropriate recommendations on how to ameliorate environmental impacts of winter road management (Note: Throughout the report, we will use the standard term chemical diecer, recognizing that materials may be used in pre-storm anti-icing (as is the normal practice at the Cascade Lakes), or for true deicing after precipitationsnow and ...

A greenhouse study was conducted on four roadside plants (Festuca rubra, Lolium perenne, Plantago lanceolata and Trifolium repens) to determine the effect of two de-icing salts {Sodium Chloride (NaCl) and calcium magnesium acetate, (CMA)} on their growth. Plants were grown in pots and supplied with solution of different concentrations of both the de-icing salts. Dry weight of shoot was determined by harvesting the plants after 45 days. Visual ranking of the plants showed that CMA is less harmful to plants than NaCl. At lower concentrations, CMA had no effect or even had favourable effect on the growth of plants. At higher concentrations, CMA decreased shoot biomass less than that caused by NaCl. Shoot weight of L. perenne, F. rubra and P. lanceolata watered by CMA was significantly (P<0.001) higher than those watered by NaCl. In another experiment, these plants were sprayed with same concentrations of de-icing salts using tap water as control. After 45 days, the effect of spraying on plant foliage was assessed by visual observation comparing with control plants. Spray with CMA showed no harmful effect on plants while spraying with NaCl showed various level of injury and damage in all the species. It was observed that CMA is less harmful to roadside plants than NaCl. However, its large-scale use is not possible due to its higher price. However, in environmentally sensitive areas, CMA can be used instead of NaCl. @JASEM

Approximately 349,000 tons of road salts (NaCl) are applied annually for road de-icing in the Twin Cities Metropolitan Area (TCMA) of Minnesota. To determine if and how 13 lakes in the TCMA respond to seasonal applications of road salt, the ionic composition of lake water samples was analyzed, and specific conductance and temperature profiles in the lakes were measured over a 45-month period. The lakes were selected based on four criteria one of which was their proximity to roadways.

Executive Summary:

Wolfville Harbour is a part of the Minas Basin, which is known to be a highly productive ecosystem. One would often visit Waterfront Park at the Wolfville Harbour and wonder what the sources were of the effluent being discharged into the Harbour. Questions rose as to what the effects were on populations such as Spartina alterniflora and Corophium volutator, which provide ecosystem services that benefit animals and humans. After doing some research, one would learn that the effluent is discharged into the Harbour untreated and unmonitored. This was alarming since stormwater effluents are derived from rainfall and snowmelt – essentially surface runoff, which can contain a myriad of pollutants, including debris and chemicals that can be detrimental to ecosystems.

A major component of stormwater effluent is road salt. As a result of this, in addition to available instrumentation for data collection, one focused this study on the effects of salinity. Spartina alterniflora and Corophium volutator can both tolerate wide ranges of salinity, however there are limits. Despite these limits, it was determined through research and review of literature that the volume of input of stormwater effluent in the Harbour is negligible in terms of its salinity. This is because the Harbour naturally experiences wide variations in salinity due to freshwater input from rivers and strong tidal influences from the Bay of Fundy that efficiently mix the water. However, it is recommended that further research be conducted to study effects of climate change on tidal influence, as well as concentrations of chemicals in stormwater effluent and their potential impact on the ecology in the Wolfville Harbour.

Michigan, like many other states, uses chemical deicers on roadways during the winter. Through meltoff and rainfall events, this road salt is washed off the roads, dissolved into runoff and drained into the surrounding watershed. In particular, the addition of chloride to surface and groundwater can affect local vegetation and biota. The purpose of the seminar project (Lynn) was to monitor water quality in a pond-well-stream system at the nearby Allendale Middle School and observe how the conductivity levels and chloride concentrations change during major meltoff and rainfall events. The small pond receives surface water runoff directly via pipe from an adjacent parking lot and road. This pond is near and upgradient from a small stream. A well was installed midpoint to intercept subsurface flow between the pond and the stream. Water samples were collected from each source every other day between mid February and early April of 2015 (daily during the meltoff event), and were then filtered and tested in the lab for conductivity and chloride. Water levels were recorded from stream and pond gauges and the well. When sampling started there was over a foot of snow and the pond surface was frozen.
Over the monitoring period, chloride concentrations ranged from 48  155 mg/l in the pond, 68  142 mg/l in the well and 22  87 mg/l in the stream. Higher chloride values were associated with elevated conductivity readings. The first major snow meltoff event occurred March 7-14, and was followed weeks later by several rainfall events. The chloride concentrations in the stream and well peaked during early snow meltoff but then decreased significantly as snow meltoff continued. Peak chloride concentrations in the pond were measured under ice cover and before meltoff. Our explanation is that the initial small amount of runoff from snow meltoff was heavily impacted by road salt and had a high concentration of chloride but that this chloride was later diluted by additional snow melt. This initial snowmelt peak was not observed in the pond, perhaps because melting ice cover enhanced the dilutional effect. Although chloride concentrations did not exceed the secondary drinking water standard of 250 mg/l, they do highlight the need for early meltoff monitoring and that dilution may mask the input of chloride to water bodies.

This section summarizes key findings from a yearlong study of the issues and practices in winter maintenance of Maine's roads. Please see the Executive Summary and the full report for additional details. Findings are grouped according to the major sections of the report.

Winter maintenance operations are crucial for achieving a reasonable level of motorist safety and public mobility on highways in cold regions. Such activities become essential when a storm with extremely cold temperatures hits the area, either as a result of normal fluctuations or as a result of climate change. Once the pavement temperature drops below 10°F, the traditional tools (e.g., granular salt) become ineffective. To achieve a drivable pavement friction condition, excessive amount of plowing, chemicals, and/or abrasives is often used, which leads to substantial cost increases and environmental concerns. The most severe 20 percent of the storms can cost 80 percent of an agency’s annual budget for winter maintenance. In this context, it is necessary to examine the best practices of highway winter maintenance operations with a renewed perspective, so as to target these extreme storms. This work presents a synthesis of relevant information in the published domain, with a focus on the traditional and innovative strategies potentially useful for highway agencies to fight extremely cold storms. This information can be valuable in the context of climate change, as certain areas may experience unusually cold snow or ice storms and face devastating consequences if unprepared for such scenarios.

As chemicals are widely used for snow and ice control of highway and airfield pavements or aircrafts, recent years have seen increased concerns over their potentially detrimental effects on the surrounding environment. The abrasives used for winter operations on pavements are also a cause of environmental concerns. After some background information, this paper presents a review of the environmental impacts of chemicals used for snow and ice control, including those on: surface, ground, and drinking waters; soil; flora; and fauna. The paper provides a state-of-the-art survey of published work (with a focus on those in the last two decades) and examines mainly the impacts of abrasives, chlorides, acetates and formates, urea, glycols, and agro-based deicers. Finally, we conclude with a brief discussion of public perception of such impacts and best management practices (BMPs) to mitigate them.

Calcium magnesium acetate (CMA) is environmentally benign deicing chemicals that can replace sodium chloride that is widely used on roads and highways at present for snow and ice control to provide safe driving conditions during winter. The price of CMA from petroleum-derived acetic acid is quite expensive. The bamboo vinegar is the by-product from bamboo charcoal production. The bamboo vinegar was used to prepare calcium acetate as raw materials, and its deicing and corrosive performances were studied in this paper. The results show that the freezing temperature of calcium acetate is lower than that of sodium chloride when they have same molar concentration, the deicing performance of calcium acetate is better than that of sodium chloride when they have same moles, while the deicing performance of sodium chloride is better than that of calcium acetate. The corrosion of sodium chloride on iron-nail and steel-nail is larger than that of calcium acetate whether they have same mass concentration or same molar concentration, and the corrosion of sodium chloride and calcium acetate on iron-nail is larger than that on steel-nail, and calcium acetate almost hasn't corrosion on steel-nail.