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  • 02 Aug 2022 11:32 AM | Smart About Salt (Administrator)

    New York wants local governments to buy American-made road salt. Why some believe that could be a costly move | Local News | buffalonews.com

    Major local governments like Erie County buy tons of road salt every year to keep roadways safe and ice free during Western New York's frigid winters.

    But a state bill requiring that rock salt be purchased in only the United States has gotten the attention of highway superintendents around the state. The proposed law could cost Erie County hundreds of thousands of dollars, and other communities are facing the same type of increase.

    "It really boils down to two things: We’re concerned about the increased cost, as expressed in the letter, and we’re concerned that if you limit the number of suppliers, that we may have some problems getting supplies of road salt when we really need them at critical times during the winter," said Bruce Geiger, legislative representative for the New York State County Highway Superintendent's Association, which wants Gov. Kathy Hochul to veto the bill.

    The state's Buy American Salt Act, which has passed in the Assembly and State Senate, was co-sponsored by Sen. Timothy Kennedy, D-Buffalo.

    The concerns raised by the association led to changes in the bill that would allow local and state government to buy from foreign sources if the requirement to buy in the United States "would result in unreasonable costs." The bill also allows governments in New York to buy foreign salt if there is an insufficient domestic supply.

    That change should put everyone at ease, said representatives for Kennedy and other bill proponents.

    "The provisions of this bill would not apply if the American-mined cost is not reasonable, not in the public's best interest or not readily available," said Mario Cilento, president of the New York State AFL-CIO, in a statement to The Buffalo News. "This bill simply allows state and local governments to go above the lowest bid in order to support jobs right here in New York and in this country."

    New York State is home to two salt mines. One is owned by American Rock Salt, which produces 4 million tons of salt a year and is based in Livingston County. The other is the Cayuga Salt Mine in Tompkins County, owned by Minnesota-based Cargill.

    American Rock Salt is the larger of the two mines and is locally owned and operated, employing roughly 400 employees, said Chief Administrative Officer Mark Assini. The mine represents the single largest employer in Livingston County.

    "We are the largest salt mine in the United States," he said.

    Supplying rock salt in New York is not a problem, he said. But freighters docking in New York ports and bringing in rock salt from Egypt, Morocco and Chili is, he said.

    Those countries offer substandard pay and don't have the same regulatory oversight regarding environmental protection or miner safety, he said, citing Egypt in particular for human rights violations.

    Those imports have caused American Rock Salt to lose between 300,000 and 400,000 tons of salt business a year, he said.

    "That's a big deal for us," he said. "That's several weeks of work for our employees."

    Opponents of the bill cite two problems. The first is that for some New York counties near the Canadian border, like Erie County, the law makes it harder to purchase salt from Canada, which is geographically close and not comparable with overseas foreign suppliers.

    Erie County likes to have salt-buying options from multiple suppliers to safeguard against potential supply shortages, said Erie County Public Works Commissioner William Geary.

    Assini also conceded that the law was not meant to apply to countries like Canada, though he also said American Rock Salt is easily capable of supplying sufficient salt nationwide. The only snag that exists is the amount of salt that truckers can physically deliver.

    Geiger, of the highway superintendents association, also said he worried about the vague language that exists to allow governments to buy from foreign sources in certain circumstances.

    "Who makes that determination?" he said, expressing concern about municipalities' potential exposure to litigation.

    Geary said Erie County typically buys from domestic suppliers like American Rock Salt but also wants the flexibility of contracting with suppliers across the border. 

    A spokesman for Hochul said the governor is reviewing the legislation. Assini said he's hopeful the governor will sign the pro-American labor bill into law around Labor Day.

    Despite Erie County budget concerns expressed two weeks ago, the County Executive's Office said it has no opinion about the pending legislation. Officials with American Rock salt said the county contracted to buy salt from American Rock Salt earlier this month. An Ontario-based salt supplier, Compass Minerals, came in with a higher price this season. 



  • 29 Jul 2022 9:04 AM | Smart About Salt (Administrator)

    Road salt: The silent threat to urban lakes (innovationnewsnetwork.com)

    The use of de-icing salts to clear roads and sidewalks in winter is a stressor of lake ecosystems. New research from the Ecohydrology Research Group at Waterloo University has shown that increasing lake salinisation linked to urban growth exacerbates water quality deterioration usually ascribed to the proliferation of algae driven by nutrient enrichment.

    Eutrophication is one of the leading causes of water quality impairment in lakes. It is driven by increased inputs of anthropogenic nutrients, mainly nitrogen (N) and phosphorus (P), which stimulate the growth of algae in the surface waters of lakes. Rapid proliferation of algae can result in so-called algal blooms which, in turn, negatively impact aquatic life and water quality. It is commonly accepted that P is the principal ‘limiting nutrient’ in freshwater lakes, meaning that the supply of P to a lake (rather than that of N) controls how much algae can be produced.1 Lakes receive P (and N) from diverse sources, including runoff from agricultural fields, seepage from septic tanks, as well as effluent from wastewater treatment plants, urban stormwater runoff, and industrial discharges. Stormwater runoff is especially important in urban areas where rainfall events flush nutrients and contaminants from residential lawns and impervious surfaces into streams and, eventually, in nearby lakes.

    In addition to high concentrations of P and N and algal blooms, the most telling symptom of eutrophication of a lake is the depletion of dissolved oxygen (DO) in the deeper part of a lake, also known as the hypolimnion.

    Road saltFig. 1: Anoxic bottom waters accompanying a strengthening of the water column’s stratification triggers internal phosphorus loading from the deposited sediments.

    Oxygen depletion occurs because, after they die, the algae sink to the bottom. Bacteria living at depth decompose the algal detritus by using the available DO. In a lake with low algal productivity, the downward mixing of DO into the hypolimnion can resupply DO faster than it is respired by the bacteria, and the hypolimnion remains oxygenated. In a eutrophic lake, however, DO consumption may overwhelm its resupply, and the hypolimnion becomes hypoxic. When this happens, fish and other aquatic wildlife are forced to move out and, in extreme cases, may even die. Thus, the logical way to mitigate lake eutrophication is to take measures to reduce the external inputs of P. The latter forms the basis for most existing strategies to mitigate lake eutrophication.2

    However, our recent work demonstrates that, in urban areas where roads, sidewalks, and parking lots must be cleared of snow and ice during winter, the application of de-icing salts also contributes to the depletion of DO in lakes.3 In essence, the wash-off of salt from the surrounding urban landscape causes the salinisation of the receiving lake. As the water becomes saltier and therefore denser, more and more energy is required to mix the water column and, therefore, the resupply of DO to the hypolimnion slows down. Thus, even if the external input of nutrients to the lake remains the same or decreases, the depletion of DO may become more severe. Moreover, much previous research has shown that, under waters depleted in DO, P deposited at the bottom of a lake is more efficiently recycled back to the water column (Fig. 1).

    Fig. 2: Location of Lake Wilcox in Ontario, Canada (a), and sketch of its drainage area (b).

    This release of P from deposited sediments is known as internal P loading. In lakes where the external P loading is reduced, but, where DO depletion of the hypolimnion persists, internal P loading may delay the return of the lake to a less eutrophic state.

    Oxygen depletion in Lake Wilcox, Canada

    Oxygen depletion driven by salinisation is exactly what we found for Lake Wilcox – a lake in the greater Toronto metropolitan area in Ontario, Canada (Fig. 2). The originally forested watershed of Lake Wilcox has undergone significant development since the early 1900s, when the land was first converted to agriculture. This was followed by urban development starting in the 1950s and further accelerating in recent decades. As a result, the impervious land cover in the watershed is now over 60% (Fig. 3a). By the 1980s, worsening eutrophication, including declining DO levels and the appearance of cyanobacteria, became a major issue. To combat increasing algal productivity and avoid harmful algal blooms (HABs), a suite of stormwater management systems, notably sediment-retention ponds, were constructed in the watershed starting in the early 2000s. Over time, more and more of the urban and suburban developments have been connected to the stormwater sewer system.

    Environmental and societal impacts on water quality

    We analysed 22 years of lake water chemistry data, from 1996 to 2018, to identify the roles climate change, urbanisation, and P and N inputs play in the observed changes in water quality and algal productivity. It quickly became clear that a major change in water quality was the large increase with time of the chloride concentration in the lake (Fig. 3b). As road salt primarily consists of rock salt, that is sodium chloride, the chloride concentration is a measure of the salt input to the lake. As seen in Fig. 3b, salinisation significantly accelerated after 2010, likely due to the increasing connectivity of the urban landscape to the stormwater sewer system, which facilitates the wash-off of salt toward the lake. At the same time, the data shows an expansion of the annual period where the hypolimnion exhibits no, or very low, DO concentrations (Fig. 4).

    SaltFig. 3: Fraction of impervious land cover in Lake Wilcox’s watershed (a) and in-lake surface water chloride concentrations (b) from 1996 to 2018.

    Further analysis of the data indicates that the external P input to the lake from the watershed has been declining since the late 1990s as a result of P retention in the stormwater management infrastructure – especially sediment retention ponds. Despite the lower external P inputs, the hypolimnion shows an enrichment in dissolved P, which is consistent with a ramping up of internal P loading. Overall, the temporal trends seen in the water chemistry data can be explained by the increasing amount of de-icing salts used in the urbanising watershed. The resulting salinisation decreases the chemical exchanges between the surface waters and the hypolimnion, therefore increasing the vertical differences in chemical composition of the water column – a condition lake scientists refer to as stratification.

    There are increasing reports of lakes in temperate climate zones experiencing declining DO concentrations and more pronounced water column stratification. Thus far, these changes have been ascribed to climate warming. Our results, however, suggest that, in cold and cold-temperate regions, salinisation may be an additional driver of these changes. Other researchers have observed rising chloride concentrations of lakes in urban watersheds of North America and Europe, generally following trends similar to the one observed in Lake Wilcox (Fig. 3b).

    Fig. 4: Mid-lake depth distributions of dissolved oxygen concentrations (DO) between 1996 and 2018. Note the lengthening of the yearly period of anoxia (blue colour) after 2005.

    Thus, the proposed salinisation-driven water column stratification and DO depletion may be widespread. Efforts to control the external P loading to such lakes may be offset by the enhanced internal P loading caused by growing DO depletion of bottom waters. Management strategies aiming to protect lakes against the impacts of eutrophication should therefore consider the role of salinisation in changes in lake water quality, including those that traditionally are associated to increasing external nutrient loading.

    References

    1: O’Connell, D W, Ansems, N, Kukkadapu, R K, Jaisi, D, Orihel, D M, Cade-Menun, B J, Hu, Y, Wiklund, J, Hall, R I, Chessell, H, Behrends, T, and Van Cappellen, P (2020). Changes in sedimentary phosphorus burial following artificial eutrophication of Lake 227, Experimental Lakes Area, Ontario, Canada. Journal of Geophysical Research: Biogeosciences 125, 5713. DOI: 10.1029/2020JG005713

    2: Kao, N, Mohamed, M, Sorichetti, R J, Niederkorn, A, Van Cappellen, P, Parsons, C T (2022) Phosphorus retention and transformation in a dammed reservoir of the Thames River, Ontario: Impacts on phosphorus load and speciation. Journal of Great Lakes Research 48, 84-96, DOI: 10.1016/j.jglr.2021.11.008

    3: Radosavljevic, J, Slowinski, S, Shafii, M, Akbarzadeh, Z, Rezanezhad, F, Parsons, C, Withers, W, Van Cappellen, P (2022) Salinization as a driver of eutrophication symptoms in an urban kettle lake (Lake Wilcox, Ontario, Canada). Science of the Total Environment (in press). DOI: https://doi.org/10.1016/j.scitotenv.2022.157336


  • 19 Jul 2022 8:47 AM | Smart About Salt (Administrator)

    Salt resistant grass being tested in Winnipeg | CTV News

    Winnipeggers may not want to think about winter right now, but the West End BIZ is working to have grass that is better prepared to deal with the remedies for winter roads.

    Joe Kornelsen, the executive director of West End BIZ, said the organization is currently testing a new kind of grass that isn't impacted by salt that is used to help icy roads.

    So far, the grass is being tested along Wall Street.

    "We've found that over the years, grass has really struggled on our major thoroughfares," said Kornelsen. "We thought we would jump on the opportunity, see if we could try something that would work a little better than the grasses that have been here."

    He said this new grass is supposed to be more drought resistant and handle salt from the roads better, as well.

    "The idea is it is a grass that is more suited to the local environment, so it can put up with more hardship," he said. "Every winter, when we are making our streets a little better to drive on, one of those solutions is salt. When that comes, gets cleared and put up on the side of the road, it all ends up in the soil and it's really hard on some grasses."

    Kornelsen said the kind of grass being used is a little bit more expensive and that is why it is being tested on a small stretch of road, but added it doesn't require as much maintenance as other types.

    "It shouldn't need to be mowed as often. So in the longer-term, we expect there would be some savings resulting from not needing to be out, mowing the lawn as much."

    He said if the project is successful, the organization will look at advocating to have it in the entire city.

  • 16 May 2022 7:32 AM | Smart About Salt (Administrator)

    How a fleet of road sweepers remove sand from Sudbury roads each spring | CBC News

    Every spring a fleet of street sweepers patrol Greater Sudbury's roads to remove the salt and sand that accumulated over the long winter.

    Last year, the city spent $1.77 million to clear the extensive road network from road sand and salt ahead of the summer.

    Kerry Lokan, the city's manager for street sweeping, said 2022 looks to be a typical year, and should be on par with what was spent in 2021.

    The money covers 26 road sweepers, 11 sidewalk sweepers and eight water trucks that a group of 45 city staff and contractors operate. 

    Lokan said the Ramsey Lake watershed and areas with high pedestrian traffic are the top priorities for street sweeping once the snow melts. But she added the city tries to vary which outlying areas it covers each day to provide a consistent level of service.

    "The process is that we send out a water truck and they spread a layer of water to try to keep the dust down," she said. "And then we send out our street sweepers."

    The city has three primary depots where the trucks deposit their loads of salt and sand. That material is then used to cover waste in the city's landfill.

    "At the end of the day, when they've finished placing the waste, they're required to cover that waste with a granular material," Lokan said. "So this helps offset some of the city's costs."

    Lokan added it would be cost-prohibitive to filter the salt and sand for use next winter. 

    Mike Popowich, an equipment operator with the city for 12 years, said he enjoys the work during street sweeping season.

    "It's satisfying once you get a street fully swept," he said. "Going to a street that's full of sand and seeing it all cleaned up, and people enjoying it, yeah it is."

    He said it takes a full team of people to clear the streets each spring.

  • 09 May 2022 7:07 AM | Smart About Salt (Administrator)

    Our View: 11 tons per mile? Maine has to stop using so much road salt - Portland Press Herald

    The changing climate is making Maine’s winter roads more treacherous, but the rock salt used to clear them is polluting rivers and streams throughout the state. That’s the tension at the heart of a new report on winter road maintenance.

    The report, from University of Maine researchers in collaboration with the Maine Department of Transportation, builds on a similar study from a decade ago, and shows that the amount of salt in both freshwater and groundwater is increasing, putting life in those waterbodies at risk.

    But rising as well is the amount of ice, sleet and freezing rain we get every winter. It will take coordination between local and state officials to make sure that keeping roads safe doesn’t imperil important waterways across Maine – and even then, in some areas, people may have to change their expectations for traveling during a winter storm.

    As the report notes, rock salt, affordable and easy to handle, is the most commonly used winter road treatment in Maine, where about 493,000 tons of the stuff was used in the winter of 2019-20 – 787 pounds for every Maine resident, or 11 tons per lane mile of road.

    There has been a steady rise in salt use over the last 15 years, as climate change has brought more-messy storms – instead of the dry snow that is so easily plowed away – and people have become accustomed to getting around regardless of the weather.

    The salt keeps the road surface from freezing, but a lot of it is washed into the water. In Minnesota, a study found that 70 percent of the salt used every year in and around Minneapolis and St. Paul stayed in the watershed.

    So it’s no surprise that, according the Maine Department of Environmental Protection, 20 streams in Maine are chloride impaired, including the Bond Brook and Kennedy Brook watersheds around Western Avenue in Augusta, and the Long Creek area around the Maine Mall.

    Once a stream is impaired, it takes a lot of effort to fix. If Maine is going to allow these areas to heal, and keep others from getting worse, it’ll have to better manage winter road maintenance.

    That’s going to take a high degree of coordination. The DOT takes care of only about 20 percent of Maine roads, with the rest under the care of local governments. They’ll need resources, information and guidance to change the way they do things now.

    The report suggests stronger links between university research, environmental monitoring and road-maintenance workers. That would help the people on the ground locally better understand how each individual storm and adjust the amount and timing of salt as needed.

    Also, the DOT should make sure local operations are aware on the latest research and training for how to apply road salt. States across the country, including New Hampshire and Minnesota, are confronting the issue the same as we are, and we can learn a lot from their trials.

    On roads near vulnerable streams, however, there may be no choice but to cut back salt use to the point where it affects road safety, at least to some degree, making it difficult to drive during or immediately after a storm.

    It’s a tough trade-off, and one that a lot of communities are not used to making. Residents need to understand the damage that road salt is doing to their environment, and what that means for the health and well-being of their community.

    Otherwise, people will continue to demand that their road be clear, even in a storm, and Maine streams will continue to fill up with salt.


  • 25 Apr 2022 9:15 PM | Smart About Salt (Administrator)

    Report urges changes in Maine's use of road salt | Environment | unionleader.com

    Maine should develop a statewide plan for reducing the amount of salt it uses to treat roads in the winter, a new report said.

    The report, from the University of Maine's Margaret Chase Smith Policy Center and Department of Civil and Environmental Engineering, said the state needs to make salt reduction a priority in parts of the state that are environmentally sensitive. The study, done in collaboration with the Maine Department of Transportation, also said officials should increase the monitoring of chlorides in water bodies and set up a dashboard to inform the public about its findings.

    The report focused on road maintenance in an era of a changing climate and said the state should do an assessment of hazardous weather conditions based on hourly weather data to help determine how snow, rain, freezing rain and sleet intermix during storms in various parts of the state. That information, the report said, can help refine predictions of how long and intense a storm may be and that, in turn, can help with decision-making on when and where to use salt.

    The study, "Road Salt in Maine: An Assessment of Practices, Impacts and Safety," comes as state officials are trying to figure out how climate change will affect road conditions and maintenance, with a consensus emerging that a warmer climate will mean worse potholes and an increased risk of water pollution from excessive salting to treat roads in winter.

    Warming weather will have a big impact on the use of road salt in Maine, the report found. It has led to increased variability in winter weather with both record low and record high snowfall years occurring between 2010 and 2019.

    The University of Maine report urged greater cooperation and information-sharing among experts as a key to preparing for the impact of a changing climate. It said that stronger links between university research, environmental monitoring and road-maintenance workers can help prepare the state for changing conditions.

    It also suggests reaching out to towns and cities around the state, possibly through the Maine Municipal Association, to help keep local officials up to date on the latest research on the impact of using salt on roads and to provide training on to use it responsibly.

    In Maine, rock salt, or sodium chloride, is most commonly used to treat winter roads because it is relatively cheap and easy to handle. However, it can also get into fresh water supplies and the Maine Department of Environmental Protection said that 20 streams in the state are now on a list of chloride-impaired urban stream watersheds.

    It can take decades for a body of water to recover from chloride pollution, the report said.

    Maine used about 493,000 tons of road salt in 2019 — 20, equal to roughly 787 pounds of salt for every Maine resident, or 11 tons per lane mile per year, the report said.

    Other states, notably New Hampshire and Minnesota, are taking steps to reduce the amount of salt needed to treat their roads, the report said, and Maine should do likewise.

  • 24 Apr 2022 8:59 AM | Smart About Salt (Administrator)

    Report urges changes in Maine's use of road salt (yahoo.com)

    Apr. 23—Maine should develop a statewide plan for reducing the amount of salt it uses to treat roads in the winter, a new report said.

    The report, from the University of Maine's Margaret Chase Smith Policy Center and Department of Civil and Environmental Engineering, said the state needs to make salt reduction a priority in parts of the state that are environmentally sensitive. The study, done in collaboration with the Maine Department of Transportation, also said officials should increase the monitoring of chlorides in water bodies and set up a dashboard to inform the public about its findings.

    The report focused on road maintenance in an era of a changing climate and said the state should do an assessment of hazardous weather conditions based on hourly weather data to help determine how snow, rain, freezing rain and sleet intermix during storms in various parts of the state. That information, the report said, can help refine predictions of how long and intense a storm may be and that, in turn, can help with decision-making on when and where to use salt.

    The study, "Road Salt in Maine: An Assessment of Practices, Impacts and Safety," comes as state officials are trying to figure out how climate change will affect road conditions and maintenance, with a consensus emerging that a warmer climate will mean worse potholes and an increased risk of water pollution from excessive salting to treat roads in winter.

    Warming weather will have a big impact on the use of road salt in Maine, the report found. It has led to increased variability in winter weather with both record low and record high snowfall years occurring between 2010 and 2019.

    The University of Maine report urged greater cooperation and information-sharing among experts as a key to preparing for the impact of a changing climate. It said that stronger links between university research, environmental monitoring and road-maintenance workers can help prepare the state for changing conditions.

    It also suggests reaching out to towns and cities around the state, possibly through the Maine Municipal Association, to help keep local officials up to date on the latest research on the impact of using salt on roads and to provide training on to use it responsibly.

    In Maine, rock salt, or sodium chloride, is most commonly used to treat winter roads because it is relatively cheap and easy to handle. However, it can also get into fresh water supplies and the Maine Department of Environmental Protection said that 20 streams in the state are now on a list of chloride-impaired urban stream watersheds.

    It can take decades for a body of water to recover from chloride pollution, the report said.

    Maine used about 493,000 tons of road salt in 2019 — 20, equal to roughly 787 pounds of salt for every Maine resident, or 11 tons per lane mile per year, the report said.

    Other states, notably New Hampshire and Minnesota, are taking steps to reduce the amount of salt needed to treat their roads, the report said, and Maine should do likewise.


  • 20 Apr 2022 6:37 AM | Smart About Salt (Administrator)

    Fenton commits to buy 1,500 tons of road salt | News for Fenton, Linden, Holly MI | tctimes.com

    The Fenton City Council unanimously approved the cost to purchase bulk road salt for next winter’s road maintenance operations from Detroit Salt Company.

    City council approved the cost at its meeting Monday, April 11 at the recommendation of Department of Public Works (DPW) Director Dan Brisson, who explained the purchase in an April 6 memo.

    Brisson said the DPW has worked with the Genesee County Road Commission (GCRC) purchasing office for the past three years to participate in its bulk road salt purchasing consortium. The purchasing office negotiated with Detroit Salt and the GCRC Board of Commissioners approved purchasing salt from Detroit Salt Company for the 2022-2023 season.

    This year, the DPW committed to 1,500 tons for the season and pricing through the GCRC contract will be $69.90 per ton. This works out to be $104,850. Fenton will work directly with Detroit Salt to place the orders and invoicing will come directly from the Detroit Salt.

     Through the Genesee County purchasing consortium, salt cost $60.84 per ton ($91,260) for the 2020-2021 season and $62.66 per ton ($93,990) for the 2021-2022 season.


  • 27 Mar 2022 8:03 AM | Smart About Salt (Administrator)

    Accumulation of de-icing salts in lakes threatens those who live there – The Nizh Times

    The accumulation of de-icing salts in the lakes threatens those who live thereThe accumulation of de-icing salts in the lakes threatens those who live there

    Canada dumps millions of tons of de-icing salts on the roads each year and this causes salt pollution which can become toxic for certain organisms in fresh water. An article by Marie-Pier Hébert, post-doctoral fellow at the University of Vermont and UQAC.

    ANALYSIS – Like many countries with cold winters, Canada sprays millions of tonnes of de-icing salt on the roads every year. Although we no longer see them under our feet in the spring, road salts do not disappear by magic: they dissolve, run off and accumulate (in part) in bodies of water.

    Saline pollution can, however, quickly become toxic to certain freshwater organisms.

    Certain species of microscopic animals, such as crustacean zooplankton (including the famous “water fleas”), can be sensitive to the increase in salinity in their environment. The loss of these small aquatic grazers could lead to significant environmental consequences, such as the proliferation of algae (normally grazed by zooplankton) or the reduction of food intake for young fish.

    As an aquatic ecologist, I study how freshwater ecosystems and organisms respond to global change. With colleagues from some twenty universities around the world, including a team from the interuniversity research group in limnology (GRIL) at UQAM and McGill University, I participated in a series of international studies in order to to better understand the response of freshwater plankton to salinization.

    AN ENVIRONMENTAL ISSUE ON A GLOBAL SCALE

    Often measured as chloride (an ion commonly found in salts), the salinity of many lakes, rivers, ponds and wetlands is gradually increasing due to human activities. The causes are multiple. Runoff from de-icing salts (such as sodium chloride) applied in winter can play a major role in colder regions, but other practices such as agricultural fertilizer application, mining, raising the sea ​​level or land deforestation also contribute to the salinization of fresh waters.

    The catch is that once the salts infiltrate our freshwater supplies, it is difficult, if not impossible, to extract them. Chloride contamination can persist for decades. The accumulation of de-icing salts, for example, can, among other things, pose problems for the management of drinking water and the release of harmful substances into water bodies. In fact, the salinization of fresh waters today represents a global environmental issue.

    LOSS OF ZOOPLANKTON AND ASSOCIATED CONSEQUENCES

    To assess the plankton fragility threshold of large-scale lakes, our international research team coordinated to carry out the same study in experimental enclosures in 16 lakes in North America and Europe. Our research indicates that increased salinity can cause loss of biodiversity and high zooplankton mortality at chloride levels similar to those measured in lakes polluted by de-icing salts.

    Similarly, in nearly half of the experimental sites in the study, the massive loss of grazing zooplankton allowed algae to proliferate. In lakes, algal blooms can reduce water clarity (which can, among other things, harm organisms living deeper) and compromise certain “services” provided by these ecosystems, such as the quality of drinking water. , fisheries or recreational activities. In other words, the sensitivity of zooplankton to salt pollution can create a domino effect on other links in the aquatic food chain, thus destabilizing the ecological balance of lakes and harming their health.

    These research results reinforce the conclusions drawn from other studies, but on a larger scale. Most studies on the subject focus on a single body of water or on model species in the laboratory. By joining forces with researchers elsewhere in the world, this collective effort has made it possible to show that a multitude of zooplankton species commonly found in lakes are sensitive to salinization, even if the environmental conditions differ.

    As in many areas of science, there are always certain limits to what can be concluded from a study. That said, when you get the same results repeatedly and in multiple places, you can start thinking about the next step: the application of research findings and sociopolitical issues.

    APPEALS TO PUBLIC AUTHORITIES

    An important observation resulting from the work: the concentrations of chloride that can cause the mortality of 50% of zooplankton are often lower than the threshold concentrations established by government directives. In other words, whether in Canada, the United States or several places in the European Union, current water quality regulations are not stringent enough to protect lakes from pollution by salt.

    In their natural state, freshwater ecosystems contain very little chloride; say, usually less than 20 mg Cl–/L. The threshold concentration considered safe for aquatic life in Canada is 120 mg Cl–/L, while in the United States it is 230 mg Cl–/L (about one or two tablespoons (s) of table salt in a bucket of fresh water).

    Although adverse effects (especially on zooplankton) may occur below these chloride concentrations, one might still believe that the more conservative guidelines in Canada are safer. But it would still be necessary for these maximum thresholds to be maintained. This is not always the case, as the World Wildlife Fund of Canada (WWF-Canada) reminds us. In fact, chloride levels in lakes polluted by de-icing salts can reach several hundred, and sometimes even thousands, of mg/L.

    Every winter, more than five million tonnes of salt are dumped on Canadian roads, pavements and parking lots; the metropolises in the east of the country, such as Montreal and Toronto, can spread nearly 150,000 tonnes on their own. The researchers call for reducing the application of road salts and considering alternative options. A recent study has also suggested some practices to improve management, such as the use of brine-based liquids to reduce the amount of salt applied. One thing is certain, it seems to have become imperative to develop dialogue with decision-makers and political leaders in order to ensure road safety while protecting environmental health.

  • 24 Mar 2022 7:27 AM | Smart About Salt (Administrator)

    Road salt is terrible for lakes and streams. Minnesota may have a solution | Grist

    Environmental activist Sue Nissen wears a teaspoon on a string around her neck, which she likes to hand out to lawmakers during hearings in the Minnesota state legislature. That’s because one teaspoon of salt is enough to pollute five gallons of water, making it inhospitable for life. 

    Road crews dump more than 20 million metric tons of salt on U.S. roads each winter to keep them free of ice and snow – an almost unfathomable number of teaspoons. Now, Nissen’s organization, Stop Over Salting, is pushing for Minnesota to pass a bill to reduce that figure by helping applicators learn how to use less of it — a technique called “smart salting.”

    The reason, she said, is because the state’s freshwater bodies are in a crisis: 54 lakes and streams are “impaired” by high salt concentrations, meaning they fail to meet federal water quality standards, while dozens of others are drawing closer to that tipping point, according to the Minnesota Pollution Control Agency. But environmental activists and scientists argue that it’s possible to maintain winter safety while reducing the amount of salt spread on streets and highways.

    “There are solutions,” Nissen told Grist. “We can still have our winter mobility and be safe … with less salt.”

    Road salt, which works by lowering the melting point of ice, is cheap and effective, reducing car accidents by up to 85 percent. But aside from corroding metal and concrete — leading to an estimated $5 billion worth of damages each year — it also ends up in rivers and lakes, where it has toxic effects on aquatic life. In January, researchers from the United States and Canada found that even salt concentrations below the threshold considered “safe” by governments were causing severe damage to organisms.

    Warnings about the effects of road salt on freshwater bodies and ecosystems first started in the 1970s, said Bill Hintz, the study’s lead author and an environmental scientist at the University of Toledo in Ohio. But salt use has tripled since then. Now, with climate change encouraging excessive salting by making winter storms more unpredictable, officials in states like Minnesota are starting to realize the magnitude of the problem. 

    The Minnesota bill, if it passes, would be one of the first state laws to encourage “smart salting,” a way to reduce road salt use while still maintaining winter safety. New Hampshire passed a similar law in 2013, while Wisconsin also has  a “salt wise” training program. In New York, the Adirondack Road Salt Reduction Task Force launched a three-year pilot program this month to reduce freshwater salt contamination. 

    The concept of smart salting encompasses a range of technologies and techniques. Brining involves laying down a liquid mixture of salt before a storm, which prevents ice from sticking and reduces the need for repetitive salting. It also includes applicators learning how to calibrate their equipment to know how much salt they’re using in the first place, as well as when to stop salting (below 15 degrees Fahrenheit, for example, salt is much less effective). Minnesota has been training applicators in these techniques since 2005, but under the new bill, certified “smart salters” would be protected from liability, preventing them from being sued for slip-and-fall accidents. 

    Nissen hopes that this protection will encourage more private applicators to be certified in smart salting practices, which are not only better for the environment but help save money on salt. But convincing them is a challenge, she said, because people have come to associate the sight of salt with winter safety. “If anybody calls in and says, ‘I don’t see enough salt,’” she said, “they call the applicator and say ‘get out there and put more salt down.’”

    This overreliance on road salt has severe environmental consequences. The most common kind used for de-icing is sodium chloride — rock salt — but calcium and magnesium chlorides are sometimes used for colder weather. Once it enters a body of water, salt is almost impossible to remove, requiring expensive and energy-intensive processes like reverse osmosis. Chloride, in particular, binds tightly to water molecules, and can be highly toxic to organisms like fish, amphibians, and microscopic zooplankton, which form the basis of the food chain in a lake or river. 

    If the zooplankton die off, Hintz said, it can trigger a chain reaction that allows algae to flourish, causing toxic blooms and affecting native fish species that can’t survive in murky waters. That should trouble recreational fishers everywhere, he said, but salt contamination has also made it into drinking water, particularly in areas where people rely on deep wells to reach groundwater. In the Adirondacks in upstate New York, a 2019 study found that 64 percent of wells tested for sodium exceeded federal limits — which can be particularly dangerous for people with high blood pressure or others on sodium-restricted diets. 

    This makes salt-reduction programs like Minnesota’s crucial, Hintz said, to “flatten the curve” of freshwater salt concentrations. “Best management practices are critically important right now,” Hintz said. 

    But reducing salt use will only slow down the crisis, not stop it, Hintz warned. Salt that’s already been deposited might take years to show up in groundwater, and how much can be “safely” added without permanently damaging an ecosystem is an “open question,” he said. And non-salt alternatives, like sand or even beet juice, can come with their own problems, silting up rivers or introducing nutrients into ecosystems that can lead to algal blooms. 

    Some cities have opted for proactive solutions — preventing snow and ice from building up in the first place, rather than melting it with salt once it’s already a problem. Since 1988, the town of Holland, Michigan, has invested in a “snowmelt” system, which uses pre-heated water from a nearby power plant to warm sidewalks and roads through a network of pipes underneath the surface, eliminating the need for salting. But solutions like this one are expensive and labor-intensive, said Amy Sasamoto, an official with the city’s downtown development district. The town spent over $1 million to install the first 250,000 square feet of underground tubing, and the system still only encompasses a few streets in Holland’s main downtown shopping area, although Sasamoto said it could expand along with future development.

    These solutions may not be scalable to something like a four-lane highway, said Xianming Shi, an engineer and the ​​director of the National Center for Transportation Infrastructure Durability & Life-Extension at Washington State University. Shi studies how “connected infrastructure,” such as cars tapped into an information-sharing network, can increase winter road safety. For example, sharing real-time information about road conditions can help road maintenance crews know how much salt to use, reducing oversalting. 

    But even improved technology and data-sharing won’t be enough, Shi said, to stop the flow of salt. Instead, it’s going to be crucial to encourage safer winter driving habits — like asking people to stay home during storms whenever possible, or to drive more slowly even on a highway. 

    “People’s mindset is more of this moment, like ‘I want to drive fast through the winter,’” Shi said. “They don’t realize that this has a hidden consequence.” 


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