Reducing chloride at the source is needed throughout the entire TCMA, not only to restore already impacted waters but also to protect all water resources. There are multiple sources to consider, a variety of options to reduce chloride, and a large geographical area to address. This section is intended to provide guidance, resources, and information to assist in making the important decisions of the what, how and when for managing chloride. The available data indicates that surface waters and groundwater that exceed the state’s chloride standards, as well as many lakes and streams that are considered to be at high risk for chloride impairment. Many lakes, streams, and wetlands have minimal or no data available, especially during critical times of the year, which makes it difficult to determine the current chloride status. Reductions in chloride loads not only benefit surface and groundwater quality, but may also reduce damage to infrastructure and vehicles due to corrosion, and reduce impacts to vegetation along roadways. Finally, improved winter maintenance practices that reduce salt usage also result in direct cost-savings to winter maintenance organizations and private applicators. Without making efforts to reduce chloride loads, the trend of increasing chloride concentrations in lakes, wetlands, streams, and groundwater is expected to continue and the cost-savings related to improved winter maintenance practices will be lost. Treating waters already contaminated by chloride through RO or distillation is impractical and cost-prohibitive.
Deicing salt is currently the most common and preferred method for meeting the public’s winter travel expectations. There is currently not an environmentally safe and cost-effective alternative that is effective at melting ice. Therefore, the continued use of salt as the predominant deicing agent for public safety in the TCMA is expected. Setting a specific chloride load reduction target for each individual winter maintenance chloride source is challenging, as is measuring actual chloride loads entering our surface and groundwater from deicing salt and other nonpoint sources in the TCMA. Therefore, priority should be put on improving winter maintenance practices to use only a minimal amount of salt, also referred to as Smart Salting, across the entire TCMA. With these considerations in mind, the implementation approach for achieving the TMDLs and protecting all waters in the TCMA is to focus on performance of improved winter maintenance practices as well as continuing to monitor trends in local waterbodies.
A standard approach to TMDL implementation is to translate the wasteload allocation (WLA) component of the TMDL directly to a numeric permit limit, which is typical for permitted facilities with monitoring requirements. In the case of urban stormwater regulated through a Municipal Separate Storm Sewer System (MS4) Permit, the WLA may be presented in the form of a percent reduction from a baseline condition. The specified percent reduction is then included in the MS4 Permit. With a performance-based approach, the numeric WLA is translated to a performance criterion. This can include the development and implementation of winter maintenance plan which identifies a desired level of the BMP implementation and a schedule for achieving specific implementation activities. Progress made towards those goals are documented and reported, along with annual estimates of salt usage and reductions achieved through BMPs implemented.
In cases where it is not feasible to calculate a numeric effluent limit, federal regulations allow for the use of the BMPs as effluent limits (40 CFR § 122.44(k)). Such a performance-based or BMP approach to compliance with WLAs is being taken by states to address the Chesapeake Bay TMDL for nutrients. The TMDL is being implemented through state Implementation Plans. Some states are taking a performance-based approach to addressing urban stormwater sources, requiring minimum levels of the BMP implementation rather than requiring specific levels of pollutant load reductions.
A performance-based approach will be tracked through documentation of existing winter maintenance practices, goals for implementing improved practices including schedules, and reporting on progress made. Entities may choose to use the Winter Maintenance Assessment tool (WMAt), which is a winter maintenance BMP tracking tool, to assess and document practices and set goals, or another approach of their choice. Entities should track progress and document efforts, including, to the extent possible, estimates of reduced salt usage as a result of improved practices. Entities that have achieved their goals for winter maintenance will have documented their practices in a winter maintenance plan. Entities that have already made significant progress in winter maintenance activities will be able to demonstrate this through their documentation of existing practices. This plan should be reviewed annually and evaluated against the latest knowledge and technologies available for winter maintenance.
The performance-based approach doesn’t focus on specific numbers to meet, but rather on making progress through the use of BMPs. Progress is measured by degree of implementation and trends in ambient monitoring. In a traditional approach with numeric targets, progress would be measured by accounting for salt applied and comparing to the targets. The performance-based approach is intended to allow for flexibility in implementation and recognize the complexities involved with winter maintenance. Because the performance-based approach does not provide a specific numeric target, a limitation of the approach is that it is not definitive on when enough progress has been made. This can only be determined by continued ambient monitoring that demonstrates compliance with water quality standards.
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This plan has been developed for many different audiences. Organizations interested in reducing the amount of salt in waters should start with an effort to fully understand the problem and determine what role the organization plays in contributing, preventing, or remediating the growing trend of increased chloride in surface and groundwater.
Prioritization of efforts to reduce chloride may be based on current water quality conditions. Waters found to exceed the state standard and their contributing watersheds should be given top priority for chloride reduction efforts. Many waters are considered to be high risk, but do not exceed the standard at this time. These areas may be given second priority unless there are no known chloride impairments in the watershed, and then the high risk waters could be given highest priority.
Prioritization of reduction efforts may also be based on the relative size and impact of the source of chloride, such as prioritizing winter maintenance activities in areas with a high density of impervious surfaces, or putting emphasis on residential water softeners for those watersheds where wastewater treatment facilities are identified as a major contributor of chloride. There may also be other ways that are more appropriate for each organization to determine where to prioritize reduction efforts.
Critical areas have been identified where chloride reduction efforts are necessary to achieve water quality goals. Two strategies have been used based on the source of chloride to identify critical watershed. The first strategy identifies watersheds with road densities of 18% or greater to identify watershed where chloride concentrations are typically above water quality standards. The maps illustrate critical watersheds statewide, in southern Minnesota, and in the norther part of Minnesota. An interactive map showing these critical areas is available on the MPCA Road Salt & Water Quality website. The second strategy used to identify critical areas for chloride reduction focuses on areas with drinking water supply wells with hard and very hard water. Through these two strategies critical areas have been identified across the state where chloride loadings are to be expected high and therefore implementation efforts to reduce chloride should be focused. For the protection of surface and ground waters implementation is encouraged statewide.
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This section provides the overall framework for the implementation strategies that are necessary to protect and restore our water resources. These high-level strategies are intended for both protection and restoration and are described by audience. The next section will provide more detailed implementation activities for the various sources of chloride. The over-arching implementation strategy is a performance-based approach. This approach allows stakeholders and regulators flexibility in the type of BMPs and the timing of implementation, and allows individuals an opportunity to develop chloride management strategies that are practical for their individual situation. Success under the performance-based approach will be measured in terms of the BMPs implemented.
A tool called the WMAt has been developed by the MPCA and is available for use by winter maintenance professionals across the state. The WMAt can be used voluntarily to understand current practices, identify areas of improvement, and track progress. While optional, everyone involved in winter maintenance is highly encouraged to use the WMAt. The tool is intended to streamline and simplify implementation goals and strategies. The tool can also be used to compare practices with other entities and learn from each other in order to achieve the greatest chloride reductions while providing a high level of service. Utilization of this planning tool will allow the user to track their progress over time and show the results of their efforts. The tool can serve as both a reporting mechanism to understand the current practices and as a planning tool to understand future practices. The planning side of the tool will help understand the challenges and costs associated with improved practices.
The overall performance-based implementation strategy for the primary audiences and a suggested timeframe is presented in the Performance-Based Chloride Reduction Strategies table with descriptive text following the figure. Secondary audiences are described at the end of this section and are not presented in a table.
Performance-Based Chloride Reduction Strategies
Link to this table
Audience | years 1-2 | years 1-2 years 3-5 | years 6-10 | Beyond year 10 |
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Winter Maintenance Leadership (state, county, city, schools, private): those not involved in day to day operations of maintenance crew. |
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Winter Maintenance Professionals (state, county, city, schools, private): plow drivers, mechanics, supervisors of crew. |
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WMOs/WDs, Environmental Organizations and Institutions, and Educators |
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Municipalities |
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Wastewater Treatment Plants and Industrial Dischargers |
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Water Treatment Facilities (water supply) |
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Citizens |
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MPCA |
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Policy Makers (city, county, state, other) |
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Winter maintenance leadership is the group responsible for hands-on efforts and operation management. This group includes the individuals in charge of the shop facilities, selling winter maintenance services, determining the type of pavement overlays, or organizing the “getting ready for winter” refresher training. This group does not include the plow drivers or their direct supervisors.
Winter maintenance leadership is a very diverse group that plays a variety of roles across many organizations. Their influence is significant and they have great potential to positively impact reductions in salt use. This group can advocate for change by understanding the economic benefits of salt reduction, including the direct cost savings as a result of using less salt.
The following table presents example activities and timelines for winter maintenance leadership to consider. Throughout implementation, goals and practices should be reviewed, assessed, and adaptively updated to reduce the use of chloride. Examples presented in this section include specific possible actions. However, these actions are intended to be examples and are not meant to put emphasis on the specific actions. Each entity will need to assess the most relevant and cost-effective actions to take in their situation to reduce salt loadings.
Examples of Implementation Strategies for Winter Maintenance Leadership
Link to this table
Assessment Items | Goals | Actions |
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Does salt leave storage sites in ways not intended? | No salty runoff water from salt sheds. | Storage sheds 1, 2, 4 are ok. Re-grade floor of storage shed 3 so water that enters the shed stays in shed. |
Do customers know that salt harms the environment and that improved practices are being implemented to reduce salt use yet provide great service? | Give all customers the opportunity to learn about efforts to reduce salt. | Meet or talk to all customers when bidding on work explaining approaches to winter maintenance and environmental protection (private contractors) or run cable TV infomercials about salt reduction reasons and strategies during November (municipal). |
Do trucks contribute salt to the truck wash water? | Re-use 50% of winter truck wash water for brine making or have less salt on truck prior to entering the wash. | Install filter system to remove wash water oils and solids, install tank to capture wash water, integrate filtered wash water in brine making system or Install a truck cleaning station before the truck wash to encourage thorough truck emptying in an area where granular salt can be easily reclaimed. |
Which organizations have been most successful in reducing salt and what are the lessons learned? | Identify outstanding success in areas of interest (i.e. storage buildings, contracts that don’t bill by the ton, using non-traditional plow drivers to get 24 hour coverage). | Look at Clear Roads research, Snow and Ice Management Association (SIMA) research, APWA research, AASHTO research, attend the Freshwater Society’s annual Road Salt Symposium and other winter maintenance conferences to identify the leaders. Talk to them directly. |
Are lower salt use pavements being installed (permeable, heated, narrower)? | Find some sort of pavement surface that requires 20% less salt on it. | Install permeable asphalt in parking lot near "Smith" lake. |
Is payment based on amount of salt applied? | Have a profitable contract without billing by the ton which encourages overuse of salt. | Look at SIMA website for example contracts that do not charge by volume. |
Is concern over liability resulting in over applying salt? | See if other states have a law to reduce liability for private companies doing winter maintenance. | Encourage legislators to look at New Hampshire’s law that limits liability of private contractors in winter maintenance. |
Watch a video: This video, produced by the MWMO and the UMN, is used to train seasonal and full-time property employees as well as business owners, front desk staff and anyone else who needs to control snow and ice in or near entrances and on sidewalks-
Winter maintenance professionals are responsible for performing outdoor, hands-on winter maintenance and those who supervise them. The primary duties include snow and ice removal from roads, sidewalks, parking lots, and trails, and applying a variety of deicers and abrasives. Some are part of emergency services and have exemption for laws that may cover weight restrictions on trucks or hours of consecutive work.
Winter maintenance professionals are employed by the public and private sectors, working for very small organizations to large organizations. Unusual hours and working in a variety of difficult winter weather conditions are typical in this industry. All of these professionals are under public scrutiny and receive comments about their work, because it directly and visibly impacts the public. There is a lot of pride within this sector as they are called on repeatedly, in the most difficult weather, to get the traveling public to their destinations safely.
The state, county, and city winter maintenance operations in the TCMA are under the extreme pressure of moving people safely on high volume, high speed roads, during all times of the day and night. Although their job is difficult, they often have the advantages of more sophisticated equipment, bigger support staff, less staff turn-over, and access to better and more frequent training than their private counterparts.
Private winter maintenance companies are very diverse and have a unique set of challenges. They often assume legal liability for “slip and falls” at their customer sites. They cannot bill clients when they attend training and have fewer incentives for training their crews. It can be difficult to locate this segment to invite them to Smart Salting trainings. The equipment used for small sites is less sophisticated and prone to over application of material. Their customers are spread out geographically, creating problems for proper and efficient storage and the transport of materials. Part-time seasonal workers fill many of the positions in these companies, which makes proper training an additional challenge for the employer.
The areas of maintenance vary greatly from seldom used sidewalks to the interstate. It ranges from concrete bridge decks to the marble steps of the capitol building. Each maintenance area has unique challenges that must be understood and mastered. The public generally does not understand or appreciate the difficulty of winter maintenance, and certainly does not understand the increasing challenges and changes coming to this industry as it moves towards conservative use of salt.
Maintenance professionals should become educated on the environmental impacts of salt and how their practices contribute to it. Maintenance professionals could attend training on lower salt use strategies, keep an open mind towards change, and look for ways to make salt use more efficient.
Operators could attend training and learn about changes that can be made on an individual basis. Many salt saving strategies do not need the cooperation of an entire agency; they can be incorporated into daily work. Other salt savings actions can be led by supervisors that will involve teamwork within the department, such as moving from manual controlled spreaders to computer controlled spreaders.
Supervisors may assess their current maintenance program using the WMAt, or other assessment techniques, to assess advanced, standard, and remedial practices. The remedial practices could be prioritized then followed by working towards improving good practices to make excellent practices.
Training opportunities, tools, and other resources for winter maintenance professionals can be found in Appendix D.
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The WMOs, WDs, and SWCDs play a significant role in the management of the TCMA waters and provide an opportunity to combine the goals and recommendations of the CMP into watershed plans. This important group, together with environmental organizations, agencies and educators are the key organizations to help increase awareness of the problem and encourage reduced salt use across the TCMA. Much of the changes in attitudes and environmental awareness has stemmed from this group of organizations. There are a wide range of possibilities for incorporating key elements of this CMP into watershed plans, as well as important roles that the WMO/WDs can take to help reduce salt use.
The WMOs/WDs/SWCDs play an important role in developing funding programs specifically for private entities, who may have limited funding options.
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Expectations for all municipalities will begin with an assessment of the existing winter maintenance practices and designing a plan to improve practices. The MS4s will have an additional requirement to report progress on the use of improved winter maintenance practices to the MPCA.
The purpose of this assessment is to determine where opportunities exist to make reductions in salt use. The information in the CMP may be used by municipalities to assess existing practices, specifically the assessment criteria in Appendix B. For a quicker and more thorough assessment, the online WMAt, currently under development, could be used. The WMAt designed to be an easy-to-use web-based tool. This tool will allow municipalities to evaluate their current winter maintenance program at a very detailed level and create a customized plan for implementing salt savings. The tool will allow an individual to assess their current practices and speculate on potential future practices to understand how to reduce the use of chlorides while still providing an acceptable level of service.
This tool is developed for winter maintenance professionals with a broad and detailed understanding of the winter maintenance operations. These professionals should conduct the assessment, then set and share the goals so that the organization can work to meet the goals.
Municipalities can choose to assess existing practices using any means. Municipalities should identify practices to improve winter maintenance activities, with priority on eliminating remedial or unacceptable practices. The implementation goal for each MS4 will be specific to the MS4.
Each municipality will have a unique implementation goal. Some municipalities have already made substantial improvements in practices and require minor effort to improve practices. For leading edge operations it is worthwhile to note the technology and tools for further reductions of salt use are constantly evolving and changing. Organizations currently demonstrating the best practices will still have to dedicate time and resources to stay current with the industry. Leading edge operations could consider sharing their experiences with other organizations that are attempting to lower salt use. For organizations that are just beginning reductions, it may be worthwhile to observe the operations and equipment of those who have already made progress on reducing salt. Networking with other operators could be part of the organization’s plan. Organizations outside of Minnesota may also have valuable insights. Many municipalities in the Midwest and Canada have developed expertise in different areas of winter maintenance and are recognized by their peers across the nations.
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This section addresses municipal and industrial WWTPs that either create saline water in their operations or receive saline water and discharge it. The concentration of chloride present in the waste stream will vary for every facility and is dependent on the source of chloride. The major source of chloride to municipal WWTP is from residential water softeners (>90% in some municipalities).
If WWTPs effluent chloride concentrations demonstrate a reasonable potential to exceed 230 mg/L, the MPCA will work with the permitted entity to include appropriate permit conditions, including monitoring requirements, compliance schedules, and possible effluent limits. If a permitted facility receives a chloride limit they will be required to identify sources of chloride.
For municipal wastewater facilities, technologies capable of removing chloride from wastewater are either cost-prohibitive, technologically infeasible, or a mix of the two. The RO and evaporation of the resulting brine is the most viable option for removal of chloride at the WWTP. The MPCA analyzed the cost and implementation concerns of using RO treatment and evaporation to remove chloride for WWTPs in 2012 (Henningsgaard 2012), which is also summarized in the section addressing costs. Based on the assessment, RO treatment and evaporation are cost prohibitive and pose significant implementation concerns.
The most feasible option for reducing chloride loading to the WWTPs is upstream source reduction. The two primary sources of chloride to WWTPs are industrial users and residential water softeners. If a facility has a chloride limit or would like to voluntarily reduce chloride, WWTPs should work through their Industrial Pretreatment Program (IPP) to identify significant users who may be contributing chloride. The WWTPs can review existing data from industrial users or can require industrial users to collect chloride data. If industrial users are identified as a significant source of chloride, the WWTP can work with the industrial user through the IPP to develop and implement a plan to reduce chloride loads
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One option for municipalities includes the potential of providing lime or membrane water softening at the water treatment plant (WTP) in an attempt to eliminate water softening at individual residences. This option assumes that all WTP users would be connected to city drinking water and would have taken their water softener offline. Water softening at the WTP has the potential to be more cost efficient than individual residential water softening for many users.
The MPCA supports any effort to reduce chloride loading to the WWTPs, including encouraging residential users to switch to high efficiency ion exchange softeners. However, the MPCA does not believe that switching residents to high efficiency softeners will automatically allow a WWTP to come into compliance with chloride permit limits. The MPCA is developing a guidance document that will provide WWTPs chloride source reduction methods, treatment alternatives, and permitting strategies that will help WWTPs to come into compliance with the chloride water quality standard. The following steps will help to reduce the amount of salt being discharged to a WWTP:
Homeowners with water softeners with an on-site septic system, salt reduction strategies should also be taken. Chlorides in on-site septic systems will infiltrate to groundwater and may result in elevated levels of chloride in groundwater which can impact water supplies as well as groundwater recharge of lakes, streams, and wetlands.
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This sector draws water from groundwater or surface water sources and tests and treats it before distributing it to residents. Municipalities that soften the water before it is distributed to households or municipalities that are considering this, care should be taken to minimize salt use and salt waste. Assess the need for soft water in the area and look for non-salt approaches such as lime softening. Consider the mass balance of how much salt is used by individual water softeners versus centralized water softening. However, users may be unaware the water from the municipality is softened or may be accustomed to having a residential softener leading to double softening. Municipalities can also evaluate how high saline water is disposed of in the cleaning and flushing process.
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This group includes everyone living or working in the TCMA. Each person contributes to the attitudes and practices that have created a high and steadily growing volume of salt to be used each year. In order to reverse this situation each person must contribute to changing attitudes and practices that are more sustainable and require less salt. The list of actions that this group can take is extensive. Citizens form public policy, set the expectations that our maintenance crews must live up to, and use salt on their own property such as water softening and salting their sidewalks in the winter. Engaging the citizenry in the TCMA offers the best chance to get salt use under control.
There are many ways to reduce salt use while maintaining high safety standards. Below are a few simple steps that residents can take to help reduce the amount of chloride entering waters. More ideas are listed on the MPCA’s website.
Citizens can look for ways to reduce salt use. Every teaspoon of salt reduction prevents five gallons of water from being polluted. Small changes can have big results. Typically the biggest salt uses are sidewalk/driveway/steps (winter maintenance) salt and water softeners, with the outdoor use for winter maintenance being the largest use.
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The MPCA will continue to provide support to stakeholders to address chloride impacts on surface water and groundwater resources, as resources allow. The MPCA will continue to monitor lakes, streams, and groundwater for chloride, in cooperation with the TCMA partners, to track progress and better understand water quality trends. The MPCA recognizes the importance of the MPCA Smart Salting (S2) training program and will continue to support and improve the training as new technologies and resources are available. The MPCA will also continue providing necessary technical assistance, resources, tools including supporting and hosting the WMAt, to its permitees, stakeholders and local partners, and to facilitate forums discussing progress of implementation of the CMP and adaptive management strategies in the TCMA as resources are available.
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State, county, city policy makers, and those that make policy to govern other entities have an important role to play in chloride management. Policy is the tool that helps speed up behavior change in areas where behavior change is not progressing or progressing fast enough. One of the challenges facing policy makers is that they may not fully understand the environmental impacts of salt. In order to enable policy makers to be more active in this area, information about the environmental impacts of salt and awareness of the existing voluntarily efforts to improve salt reductions is necessary. There are many policies and actions that can be considered to assist with reducing salt use.
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This group includes those that have a smaller, but important, role in reducing the amount of salt entering surface and ground water.
The property manager or contracts department for any organization hiring winter maintenance services should consider requiring those bidding on work to have successfully completed the MPCA Smart Salting training. When crews are on-site conducting maintenance work a high percentage (to be determined by contracts department) should have successfully completed the training within the past five years. Here are things to consider when negotiating a contract for winter maintenance services:
MPCA’s training program.
Snow plowing and deicing of parking lots will be done in a manner similar to guidelines provided under both the Minnesota Pollution Control Agency and the Minnesota Department of Transportation Winter Parking Lot and Sidewalk Maintenance manual provided to LESSOR.
LESSOR shall request LESSOR’S vendor to attend Smart Salting training offered by the Minnesota Pollution Control Agency. The following link provides information about the Minnesota Pollution Control Agency’s Road Salt Education Program.
Ensure that grant opportunities are available for protection and restoration of surface and ground waters for chloride. Consider ways to ensure a simple application process and equal access to funds for non-traditional source reduction (pollution prevention) projects addressing chloride. Possible areas include:
For all new drivers, those getting additional licenses such as commercial or motorcycle licenses, and those moving into Minnesota, consider educating about winter tires, appropriate winter driving, and the environmental impacts of salt. Include training on winter driving, the temperature range at which salt does not work, how bridge decks and ramps freeze before the roads, and other tips for safe winter driving. Teach drivers to respect the plowing operations and take pressure off of public works departments for instantly cleared surfaces. Send information with driver license renewals to current drivers on tips for winter driving.
Become educated on the issues with high-salt-use surfaces and the impacts to water resources. Look for opportunities to invent, test, and implement lower-salt-use pavement surfaces. This includes sidewalks, parking lots, roads, bridges, ramps, trails, parking ramps, steps or other highly salted surfaces in the winter months. Possible areas include, but are not limited to:
Understand the impacts of chloride to water resources and the pathways it takes to get there. Look for opportunities to invent, test, and implement techniques to prevent salt from entering water resources after application or for strategies to mitigate for it. Problem areas to consider include:
The primary source of chloride from agricultural lands in the TCMA is from fertilizers and land application of food processing waste and biosolids from municipal sewage treatment. Excessive chloride concentrations on agricultural lands can be harmful to crop growth in addition to contributing to elevated levels of chloride in surface runoff and groundwater infiltration. Conservation practices and nutrient management not only protect water resources, but can save farmers money. Development and implementation of nutrient management plans could potentially be conducted for agricultural lands. Conservation practices and nutrient management planning information and guidance can be found at the Minnesota Department of Agriculture website.
The Minnesota Department of Health (MDH) should continue to monitor chloride in drinking water, as resources allow. The Metropolitan Council may continue to monitor chloride in lakes, wetlands, streams, and groundwater, as well as chloride in wastewater discharges in the TCMA. The Minnesota Department of Natural Resources (DNR) could continue to monitor chloride impacts on aquatic life, plants, and animals. The Board of Water and Soil Resources (BWSR) will continue to administer grant programs to protect, enhance, and restore water quality in lakes, rivers, and streams in addition to protecting groundwater and drinking water sources from degradation, as resources allow.
The MnDOT should continue to provide in-house training and leadership throughout the state in an effort to enable the implementation of effective chloride reducing BMPs. This includes research on innovative technology and passing the knowledge on to others. The Minnesota Department of Agriculture could potentially work with farmers to develop nutrient management plans, which include methods to reduce chloride-based fertilizers.
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Chloride management is a challenging issue in Minnesota and requires a balance between public safety and the environment. In addition to the balance, chloride management is complex since every winter event is different. The different events can be a result of the type of precipitation, temperature, longevity of the event, timing of the event, etc. In addition to variations in each event, winter seasons can be highly variable from year to year.
Snow and ice maintenance practices vary between road authorities and private applicators. Training, equipment, available resources, client expectations, and political pressure all factor into the amount of deicer being applied.
There is no single BMP that can cost-effectively remove snow and ice and maintain an appropriate level of service for all of the various situations. Chloride management can only be achieved through implementation of an array of different BMPs. The BMPs vary by effectiveness in reducing chloride application and cost of implementing the BMP.
The CMP includes an arsenal of BMPs, which give chloride applicators multiple ways to reduce chloride. This provides BMPs that can be used by high-use/high-experience entities all the way down to low-use/low-experience entities. A wide range of BMPs also allows greater flexibility in the timing and extent of implementation of BMPs.
Traditional BMP strategies can be implemented by chloride applicators. The primary recommended strategies include, but are not limited to:
These strategies are centered on the continued use of chloride containing products in the most efficient and effective manner possible. This approach assumes maintaining the same level of service. There are several industry shifts that are needed to reduce salt waste. These changes are applicable to all winter maintenance areas in which a high level of service is expected: roads, parking lots, and sidewalks. Implementing the strategies above will lower salt use, but it may not be reduced enough to protect or restore all water resources.
As part of the stakeholder process to develop the CMP, a TechEx was developed and consists of hands-on salt applicators and suppliers. The TechEx was engaged to better understand the state of the practice and the BMPs available to the winter maintenance industry. The TechEx provided valuable information on specific BMPs that are currently being used by various entities and the benefits of implementing these salt reducing BMPs. This team has been instrumental in the development of the WMAt that will assist winter maintenance organizations in developing their own customized salt reduction plan. Their knowledge, experience, and dedication to using smart salting techniques has been utilized to create this first ever comprehensive evaluation of all available chloride BMPs. Utilization of this planning tool will allow the user to track progress over time and show the results of the efforts.
The tool can serve as both a reporting mechanism to understand the current practices and as a planning tool to understand future practices. The planning part of the tool will help the user understand the challenges and costs associated with improved practices. The WMAt provides a more detailed and comprehensive list of the BMPs available to winter maintenance professionals.
While the preferred and most effective approach for developing a chloride reduction plan for individual winter maintenance programs is to utilize the WMAt, here are a few BMPs that have been proven to reduce salt use.
These BMPs may not be practical for all winter maintenance programs and should not be considered the best or only options for salt reducing activities, but rather a list of BMPs that many programs have already begun implementing and are seeing reduced salt use as a result. To determine the activities appropriate for each organization please visit the MPCA’s Stormwater Manual to utilize the WMAt.
The MnDOT is a leader in winter maintenance related research in the state. Research reports and technical summaries on the latest research can be found on the MnDOT Research Services website.
The continued use of chloride containing deicing materials to provide safe winter conditions may not be a sustainable long-term solution. Therefore, considering practices that fall outside the current and common methods for winter maintenance are worth evaluating. When evaluating non-traditional methods, it is important to consider the environmental impacts of the methods.
Non-traditional approaches require public acceptance in terms of costs, expectations, and changes in behavior. Implementation of these practices will require a combination of messaging to the public which includes discussion of the potentially significant costs to individuals and government. Five of the main areas where change may be considered include:
In this scenario, the public would be given a lower level of service on the roadways, parking lots, and/or sidewalks. Physical removal of snow would likely remain the same but the salting would diminish. There are many ways in which winter maintenance professionals could change their level of service. For example, roads could be salted less frequently or perhaps less of the road could be salted. Instead of roads free of ice and snow from shoulder to shoulder, the melted zone could be reduced, perhaps to the middle of the drive lane. Salting could be restricted to critical areas such as intersections, ramps, hills, and high speed roads. Road salt would still be used, but to a lesser extent.
Winter speed limits – alter the speed limits to match the driving conditions during winter storm events or super cold weather times when black ice is present. The MnDOT currently uses a managed traffic lane approach for dealing with high traffic volumes and congestion on the interstate system within the TCMA. It provides a way for the MnDOT to suggest a speed that will reduce braking and further congestion. This same approach could be utilized to manage the expectations of drivers in terms of speed during snow and ice conditions. The temporary winter speed limit approach has been taken in several states including Illinois, Pennsylvania, Colorado, Maine, and Oregon.
In this scenario, government transportation agencies and private industry would adopt different forms of pavement that can be kept clear with less or without the use of salt. This could include various forms of heated roadways, new types of improved traction surfaces, surfaces constructed with internal anti-icing features, solar roadways which could generate heat as well as electricity, permeable pavements, and flexible pavements. Narrower roadways may also allow for less application of deicing material.
Urban design methods such as parking ramps and covered parking, skyways or covered walkways, porous paving, public transit, transit-oriented development, and higher density development may also help to reduce impervious surfaces, reduce impervious surfaces requiring deicing, and reduce the overall chloride use.
Use of winter tires or other types of tires with improved traction could be required. This might possibly reduce the expectations for a high level of service, and any salt savings would need to be linked to this secondary step of diminished road melting. There remain concerns that driver behavior would not change enough to allow less salt use. Some types of tires have been associated with increased road wear and subsequent pollution, and Minn. Stat. 169.72, prohibits studded tires. The challenge with this approach lies again with public acceptance and driver education on how to safely use winter tires. There would also be a direct cost to consumers and the enforcement of such a requirement. Increased maintenance to roads would likely be an indirect cost associated with this approach, which the resulting salt savings would be modest at best.
Work with large employers to establish a work from home policy during snow events for employees who have suitable jobs. Possibly this will reduce traffic enough during critical times to allow maintenance to be more effective with less salt.
There is a fairly wide variety of other chemicals that can be used for anti-icing and/or deicing, chemicals which do not contain chloride. However, there are significant environmental concerns with most of the existing alterative products. In general the toxicity of non-chloride based deicers is often more severe to surface water organisms in the short term as the chemicals breakdown. There are fewer long-term concerns with non-chloride deicers, which should be evaluated against the long-term permanency with chloride. Of the four strategies, this may be the easiest to implement, but the environmental impacts of these alternatives are the highest of the options listed and needs to be better understood.
See MnDOT’s Transportation Research Synthesis Report: Chloride Free Snow and Ice Control Material for further information on non-chloride deicers and other non-traditional strategies such as permeable pavement, reducing road widths, solar, and others.
Snow melting equipment may be a viable solution in some cases. However, the costs, practicalities, and other environmental consequences of snow melting equipment should be explored further before implementing this method.
http://stormwater.pca.state.mn.us/index.php/Smart_Salting_(S2)_training_certificate_holders
More training and professional development opportunities can be found in Appendix D. MS4 Permit Implications/Strategies/Reporting
One of the challenges for public road authorities is the variability in road types, conditions, and meeting driver expectations. Each municipality is faced with unique challenges and circumstances that will play a role in determining the specific BMPs implemented. Development of winter maintenance policies/plans that are proactive and aim to minimize salt use is a critical first step for all winter maintenance programs to begin implementing the BMPs in an effective and strategic way. Training and regular professional development for all applicators is another key strategy to allow winter maintenance programs to reduce overall chloride use while providing an appropriate level of service.
Municipalities in the TCMA make up the most significant portion of salt applicators and would be expected to take on the majority of the BMP activities for reducing chloride. Those municipalities with a National Pollutant Discharge Elimination System (NPDES) Permit with the MPCA in a chloride impaired watershed will be required to report progress on the implementation of the salt reducing BMPs beginning after issuance of the next Phase 2 MS4 permit, which is expected to occur in 2019. The Phase 1 MS4s, (St. Paul and Minneapolis) will be asked to report their progress in 2016.
The WMAt is a valuable resource to MS4s in terms of prioritizing and implementing the BMPs. Use of the WMAt is not a requirement but will allow each MS4 to determine their own priorities that may be based on cost, location, ease of acceptance, or other important factors unique to the MS4’s particular situation. The WMAt provides the specific BMPs related to all areas of winter maintenance to aid in the development in a detailed plan that meets the unique conditions of each individual program and can be prioritized and implemented according specific needs and constraints.
Another valuable resource for public road authorities is their peer group. Several public road authorities have improved practices, significantly reduced chloride use, and have recognized cost savings by implementing BMPs. These success stories, when shared between entities can be a great way to demonstrate specifically how chloride reductions have been successfully achieved. Case studies describing some of these local success stories and specific areas of improvement are discussed below in Section 3.5.
The MS4 reporting will consist of discussion of the BMPs that have already been implemented and the BMPs that are planned, including a timeline for implementation. Further information on reporting requirements can be found on the MPCA MS4 program website.
A major challenge in the overall reduction of chloride use in the TCMA is getting private applicators to reduce chloride usage. There are five primary hurdles related to this effort:
Two potential approaches to educating/training private applicators include a required training approach and a voluntary training approach, both discussed further below. A required training assumes that an ordinance or other regulatory mechanism is adopted by a governing body that requires training. A voluntary approach assumes that there is no ordinance or regulatory mechanism in place.
Potential Required Training Approach: for watersheds with chloride impairments (or suggested reductions)
Voluntary Training Approach:
The winter maintenance industry has changed since the MPCA Smart Salting training program started in 2006. The training itself has also changed. By making the training valid for a fixed number of years, this will encourage on-going awareness of the winter maintenance BMPs, keep the industry current with regulations, and strengthen communication between maintenance organizations and strengthen communication between the environment and maintenance. For optimal success these considerations should be made:
In addition to education, legislation that limits liability for private applicators that are certified under the Smart Salting training program would enable them to use less deicer without fear of litigation. An important aspect to a statute like this is requiring training in order to maintain an appropriate level of service. The State of New Hampshire passed a new law, RSA 489-C effective November 1, 2013, which limits the liability of business owners who contract for snowplowing and deicing as long as the applicator is certified through the New Hampshire Green SnowPro Program. The entire law can be found at: www.gencourt.state.nh.us/rsa/html/NHTOC/NHTOC-L-489-C.htm.
Feedback from stakeholders in Minnesota has indicated that many of the private applicators over-apply salt because of concerns about litigation. A law similar to New Hampshire’s RSA 489-C could change salt application behaviors of private applicators by limiting their liability.
In some cases, compensation for winter maintenance is based on the amount of salt used, which can incentivize over-application of salt. In this case, a boilerplate should be developed and performance based contract for private entities to use when contracting for winter maintenance services. Performance based contracting methods and the boilerplate contract could be part of the education and training programs for private applicators.
A clear message on why reducing chloride is important for the environment, important for saving money, and how to effectively apply chloride will be the key to changing salt application behaviors by homeowners and small businesses. This messaging should be carried out by various state and local governmental entities in order to reach a broad range of people in the TCMA.
Nine Mile Creek approached this by providing a measuring cup type salt scooper to homeowners and small businesses in order to raise awareness of the amount of salt they are using. Homeowners currently not using salt should be encouraged to continue without salt. See detailed survey results in Appendix C and Section 3.4 for additional information on public education.
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The average Minnesotan values having clean, healthy water resources. The same Minnesotans value safe driving conditions on roads and bridges. These two public goods are in direct conflict and create a serious dilemma for local government and businesses. Driving in difficult winter road conditions is a problem that directly impacts daily life for nearly all members of the public. It is immediately recognized and felt. Conversely, the problem of chloride pollution causing permanent damage to local waters is something that must be imagined and may not be felt until much later. Extreme public pressure is often brought to bear on local officials to address the immediate problem of icy roads, in spite of the long-term consequences of permanent damage to water resources that will have severe and wide impacts.
When confronted with this dilemma, most citizens will acknowledge this challenge needs to be resolved. However, the expectation is this is government’s problem to solve. This dynamic – the government must solve this problem, while the public simply observes – is at the root of this challenge. Changing this expectation is needed to change the over use of chloride to manage winter roads, parking lots, and sidewalks.
Traditional information and education campaigns are important tools in raising awareness about chloride impairments in lakes, rivers, and groundwater. However, if the goal is to create long-term, sustainable change in the practices surrounding the use of salt and other chloride products (e.g., sidewalk deicers, water softening agents) additional strategies will be needed. Research shows that education may be effective in altering some citizens’ behaviors for the short-term, but these changes are not likely to be widespread or sustained unless they are coupled with organizing strategies that provide supportive structures for citizen collaboration and public action (Dietz and Stern, 2002).
In order to ensure that a new mindset and social norm are achieved around winter road expectations and the use of chloride, a long-term approach to organizing stakeholders will be needed. Changing attitudes will require significant, long-term, and small-scale organizing of homeowners to work in partnership with WDs, WMOs, lake associations, and neighborhood organizations. These community-based organizations are best poised to deliver outreach and programs.
Outreach and education programs remove the barrier of lack of information and encourage people to make changes in their day-to-day practices. However, research has found that there are often other barriers that keep people from changing their existing practices. One effective strategy for overcoming these barriers is to couple information with relationship-building and collaboration support systems in small-scale settings. Community associations, civic groups, and lake associations that already organize neighbors around the issue of water quality can expand their learning and strategies to include addressing chloride pollution. The trusting relationships that develop in these contexts and citizens openness to learn and act, increases the possibility they will consider new information and assistance
Trusted local leaders delivering information will likely have greater impact than blanket media campaigns, fact sheets, or other educational materials. This approach can be especially effective when coupled with an effort to develop a sense of citizenship and common good while addressing water quality as part of an overall outreach and organizing strategy. Inspiring citizenship and caring for the common good and community, is showing promise in sparking interest in participation.
Development and implementation of public education and involvement is critical and necessary to the success of chloride management in the TCMA. Based on feedback from stakeholders, a multi-agency approach to public education and involvement is needed to reach a large and diverse group of salt applicators with a range of motivations related to salt application. Public education and involvement can be accomplished through multiple venues such as mainstream news media, social media, permanent and variable message signs, elementary and high school education, and other resources aimed at reaching the general public. The MPCA road salt and water quality website maintains a list of available educational resources. Educational resources for educators and citizens are also available in Appendix D.
Changes in personal practices and attitudes can be the most challenging and time consuming and require short- and long-term strategies. Current winter driving expectations is a result of decades of increasing road salt use and improvements to the level of service. The improved level of service has allowed the traveling public to drive faster with greater confidence during snow and ice events. A long-term strategy is needed to reverse this expectation. Education of young drivers could be an important starting point in changing driver behaviors to expect a lower level of service during snow and ice events.
As part of the TCMA Chloride Project, an education committee was created to identify the principal audiences for winter maintenance education and discuss potential opportunities and strategies to increase awareness about salt use and associated water quality issues. The EOC included state and local education specialists from the MPCA, counties, the UMN, The Freshwater Society, WDs, WMOs, conservation districts, and MnDOT which met four times over the duration of the TCMA Chloride Project.
The following is a summary of recommendations provided by the EOC and other stakeholders. These recommendations should be considered by professionals in relevant organizations and roles. In addition to the great information and recommendations gathered from local education specialists, there is a need for government and citizens to collaborate to make effective policy choices for reducing salt use.
Strategies for Recruiting for Training
Demonstration projects can be used to test the organizing approaches for building partnerships between citizens and government or property owners to work together to solve the challenge of chloride use and water resource impairments. The demonstrations will likely be most successful where community capacity around environmental issues exists. Local leaders should be supported to experiment with building partnerships across sectors to co-develop strategies for chloride reductions by municipalities, businesses, and households. The demonstrations can employ pre- and post-evaluation to determine whether the approach achieves meaningful outcomes over time. The outcomes will determine whether the efforts should expand past the pilot stage. If defined outcomes are significant, the plan should be developed to scale to metro-wide and beyond application.
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Reductions in the use of deicing salt are possible through smart salt use and adoption of winter maintenance BMPs. Many winter maintenance organizations have already begun implementing salt reduction practices across the state. Examples of local efforts to implement smart salting strategies are included in this section to provide ideas that may work for other winter maintenance programs and to highlight the great work already being done.
Curt Pape presented this information at the 2012 Road Salt Symposium.
The Automated Vehicle Location (AVL) uses GPS equipment to track where and how much salt is applied. The Maintenance Decision Support System (MDSS) is used in conjunction with the AVL will use multiple factors to decide when, where, and how the salt should be applied. The average savings achieved through the use of the MDSS and AVL is 53 percent.
Over 11 ice and snow events, a total of 71,745 tons of salt was applied at a total cost of $4,356,351. Using the projected average savings from implementing MDSS and AVL of 53 percent, the total savings would be approximately $2,308,866, which would also prevent over 38,000 tons of salt from entering lakes, streams, wetlands, and groundwater.
This information was taken from the Dakota County Smart Salting training KAP Study Report (Eckman et al. 2011).
The snowplow drivers in Dakota County, Minnesota, attended the MPCA sponsored Smart Salting training course presented by Fortin Consulting and the Minnesota LTAP in 2008. To test the effectiveness and impact of the course, a knowledge, attitudes and practices (KAP) was administered to these drivers before the course to establish how the snowplow drivers approached the job. After two winter seasons, approximately 14 months after the initial training, the same KAP test was administered again to measure any change. Steps were taken to maintain confidentiality of the respondent and to insure the same people were compared. Seasonal and temporary employees were not used in the comparison.
In September 2008, the results of the survey showed that Dakota County plow drivers had good general knowledge and good practices, but they were in need of some improvement. While the drivers were aware of the county’s winter maintenance policy, the independent judgement factor was a little more difficult. For example, only 60% agreed they “minimize the use of deicers during a snow storm.” Although this type of information is useful, the goal was to evaluate how effective the training was to actually make a difference in all three facets of knowledge, attitudes, and practice.
The follow up survey in November 2010 showed mixed results. Most importantly, some of the significant improvements were under knowledge and practices.
Dakota County plow driver survey
Link to this table
Question | 2008 Response (Yes) | 2010 Response (Yes) | +/- percentage change |
---|---|---|---|
I minimize the use of deicers during a snow storm | 60% | 96% | +36% |
During calibration I have set the computer speedometer to match my trucks speedometer. | 40% | 73% | +33% |
I use an application rate chart to determine the amount of salt/sand to apply | 35% | 76% | +41% |
I avoid using road salt when pavement temperature is below 15 degrees F | 27% | 88% | +60% |
I document my winter maintenance actions | 73% | 69% | -4% |
The policy encourages plowing before two inches of snow accumulation | 92% | 84% | -8% |
Equipment is calibrated for each type of deicing material used | 92% | 88% | -4% |
I have ground-speed controlled sanders-the auger is installed and working | 84% | 77% | -7% |
I plow before applying deicers to minimize the dilution of the chemical | 96% | 92% | -4% |
I avoid salt/sand mixes | 72% | 68% | -4% |
The areas that showed declines were areas that either additional training or clearer policies could produce better outcomes. The majority of the questions indicate there has been a positive shift in knowledge, attitudes, and practices since attending training. In addition to the KAP survey, the amount of actual salt has been reduced to further underscore the success of the training. The county used an average of 405 tons of salt per snow event in 2007, the winter season before attending the training. Post training, the county reduced their usage by about 50 tons per event to 355 tons of salt per snow event. This reduction correlates to about 40 million gallons of freshwater protected from chloride contamination per snow event.
This information was supplied by Scott County.
The past practice of Scott County was to use a mixture of 1:1 sand and salt that was applied with uncalibrated spreaders. No policy or guidelines were in place for mixture ratios or spread rates.
The county started a training program for the supervisors and operators to familiarize them with the effectiveness of salt depending on pavement and air temperatures. After attending the training, treated salt was added to the county’s material options. Each plow truck was supplied with information about the route, how many lane miles, and tables for each material and its spread rate based on the temperature.
It took several events to convince the members of the team of the effectiveness. There was not an instant buy-in from the drivers, but after several events, most of the drivers were impressed with the results using the treated salt. During the course of 8 to 10 events, the usage of the sand and salt declined. The winter maintenance teams stopped using the sand/salt mixture, although small cities and townships continued to purchase the sand/salt mixture from Scott County.
By implementing the new practices and policies, the drivers found a single load, or less, was enough to treat the route. Anecdotally, the drivers reported the usual practice would be to apply three or four truckloads of the sand/salt mixture in a single event. The County estimates that 1,500 to 2,000 pounds of the sand/salt mixture was applied per mile lane each event. After the change, the usage dropped to about 424 pounds per lane mile per event. The savings of over 1,000 pounds per lane mile paid for the increased costs of the treated salt. This correlates to a 25-30% reduction of chloride entering lakes, streams, wetlands, and groundwater. Scott County maintenance believes this is the most economical and environmentally sound approach available.
St. Louis County began working on reducing salt contamination by erecting dome buildings and coverall type buildings where they store their salt and sand. This has been accomplished by the county alone and through partnerships with Net Lake Indian Reservations, Hibbing, Ely, and the state. They now have all of their salt and sand supplies covered. Hibbing, Pike Lake, and Ely have built-in storm water drainage ponds to stop runoff into lakes and streams.
In 2008, trucks with calibration technologies were purchased to make the application of materials more precise. They will continue to purchase trucks with this technology. In addition to this technology, the newest trucks in the fleet have pre-wetting equipment and GPS/AVL technology. Forty-six trucks purchased prior to 2008 have been retrofitted with the calibrated controls and pre-wetting equipment. Plans to add the GPS/AVL have been made, depending on available funds. St. Louis County has expanded their salt brine making capabilities to five additional facilities by partnering with MnDOT to share capabilities in Hibbing and Pike Lake.
St. Louis County currently uses approximately 19,265 tons of salt each year and 67,440 cubic yards of sand, at a cost of around 1,207,338 and 202,320 dollars respectively. Through the addition of new equipment and implementation of better practices, St. Louis County projects they will reduce their salt use by as much as 45%. The projected monetary savings is 634,346 dollars per year. The environmental savings is the prevention of 8,669 tons of salt from entering the environment, and saving 7 billion gallons of freshwater. By reducing the application of the less effective sand/salt mixture, St. Louis County will be responsible for reducing 30,348 cubic yards of sand from entering the rivers and streams.
Cottage Grove saw a significant decline in salt usage after attending training. Their usages for the past few years, per event have declined steadily.
The City realized a savings of 694 tons of salt for the 2011-2012 winter season. This translates into a savings of 40,000 dollars in one season.
This information was gathered from Tom Struve’s presentation notes, 2011.
The city of Eagan discontinued mixing sand and salt in the 2005-2006 winter season. Without dropping the level of service to residents, the city was able to eliminate a five year average purchase of safety grit. The elimination of the 3,249 tons of grit led to a 65% reduction in spring street sweeping hours. This elimination saved Eagan 70,000 dollars per year.
In 2008, Eagan began using EPOKE winter chemical application technology. This enabled the city to use a precise chemical application of up to 90 gallons of brine per one ton of salt and realize immediate improvements. Also, the addition of AVL allows snowplow drivers to inform the police of the location of cars remaining on the streets during snow emergencies. The police receive a map by 8:00AM showing the exact location of the cars, which makes the mechanical removal of snow much more efficient and effective for the snowplow drivers.
The city of Eagan implemented additional practices including: pre-wetting material at the spinner; using salt brine to 10-15 degrees and substituting magnesium chloride when the temperature falls below 10 degrees; limited uses of Clear Lane for severely cold temperatures; and, managers directing the lane mile calibrated application rates. Eagan still has a stockpile of sand, which they rarely apply. Most importantly, Eagan has the buy-in of the operations staff, which has been very important for their success.
Despite the new practices, the level of service that Eagan provides for residents remains high. The residents have high expectations for winter road maintenance and Eagan has been able to make changes to reduce salt use, while also meeting the expectations of the community.
The winter maintenance operators and managers for the city of Minnetonka are committed to the need to reduce salt to protect the environment. This city delivers high service and the residents expect excellent service. Minnetonka Public Works maintains 254 centerline miles of streets which includes 562 cul-de-sacs. During full scale snow events of 2 inches or greater, 20 plow trucks, 2 loaders, and 7 pickups are mobilized to perform snow removal.
Prior to the 2010-2011 winter season, Minnetonka installed a Cargill Accubrine automated brine production system. The system can blend up to two other products with the brine produced to aid in temperature suppression of the brine when needed. There are five 6,500 - gallon tanks to store the finished products or purchased additives. The City currently uses a corrosion inhibited 32% calcium chloride to pre-wet salt when temperatures are below 15 degrees F. Outside agencies, including Hennepin County and neighboring cities, purchase brine for use. The brine is used to pre-wet the salt before it is applied to the road and for anti-icing prior to a snow event.
Prior to snow events, Minnetonka uses a 2,000 gallon tanker truck and a truck with a 900 gallon tank that are used to pretreat the highest volume streets with brine at a rate of 30-35 gallons per lane mile. The fleet is currently being retrofitted with new technology: pre-wetting equipment, on spot chains, Force America data, and AVL.
All 20 plow trucks and 1 spare truck in the snow fleet are equipped with ground speed controllers to accurately apply and track salt used. The trucks are also equipped with brine tanks so that the salt that is discharged from the trucks is treated with brine at a rate of 10 gallons per ton of salt.
The City subscribes to a web-based weather service that provides a 48-hour weather forecast which is updated every hour. Information provided includes air and pavement temperature, wind speed, dew point, snow and ice accumulation totals and rates/hour, when the precipitation will start and stop, and also provides recommendations for salt and liquid application rates. This information supports decisions for properly staffed crews for the event, application of anti-icing liquid, and the application of the correct liquid for pre-wetting the salt. City staff can compare information from around the state with regards to road temperatures, wind speed, and radar to see how an approaching storm will affect Minnetonka operations.
The AVL is used on all mobile snow equipment to track vehicle location and salt application. A real-time, citywide map shows progress of snow removal operations and allows movement of plows around the City to address any missed areas or areas that are running behind schedule. The system will also send an email notification if an error occurs with a salt controller on a truck. Depending on the status of the plowing and storm, staff determines whether to bring the truck in for repair. Even if in an error state, the controller is able to track salt application provided the spreader is functioning. Four trucks are equipped with air and road temperature sensors which are monitored through the AVL system.
The city of Minnetonka has achieved its goal set by the Nine Mile Creek Watershed during the 2010-2011 season. They reduced application of salt to 4.2 tons per mile from 7.022 tons per mile. This was a reduction of 180% during a normal season.
Minnetonka is focused on improving the use of liquids. For the 2012-2013 winter season, the trucks averaged 3.5 gallons/ton of brine for pre-wet and the city realized that the nozzles were not calibrated for the gravity application system. The nozzles are now calibrated along with the salt controllers before winter and the average for 2014-2015 increased to 6.2 gallons/ton. This is still below the 10 gallons/ton rate the trucks are calibrated for but it is improving.
This information was provided by Freshwater Society, 2014 Environmental Leadership Award on February 6, 2014.
In 2009, Norwood Young America city employee’s attended an ice and snow workshop where they learned the importance of calibrating equipment. In 2010 staff attended another workshop on snow and ice control practices. After training, the city purchased tanks for pre-wetting salt. Through the implementation of recommended practices and attending the Smart Salting training, the city was able to reduce their salt usage by almost half in 2010. On average, the city had been using about 600 tons of salt per year.
After training, the city averaged 350 tons per year, saving 17,500. This success has encouraged the city to continue to improve their operations and practices.
The city of Plymouth began implementing salt reduction practices in 1996 by implementing the use of brine. At first, brine was used on a limited basis, but expanded through 2004. The city began implementing anti-icing and expanded its application by purchasing a 1,300 gallon tank in 2007. The AVL technology was added to the vehicles in 2009 to track the routes and salt application. The city continues to improve, and in 2014 purchased its most recent 1,300 gallon brine tank for anti-icing.
As with many municipalities, it is difficult to track the reductions with absolute certainty. The City has experienced growth in excess of 30% since the mid-nineties. Granular salt use has been decreased by 40% despite this growth. Despite the 40% reduction in granular salt, it should be noted that there is still salt applied in the form of brine for anti-icing. The City estimates that the overall reduction, since the mid-1990s, is approximately 25%
The information provided below is based on information provided by the city of Prior Lake for the 2010 American Public Works Association Excellence in Snow and Ice Control awards ceremony. The city of Prior Lake maintains approximately 100 center lane miles of street with 10 maintenance personnel and one supervisor. Starting in 2003, Prior Lake implemented a winter maintenance program which includes:
The staff buy-in and support was critical to the success of this program. Education was important for this; they started with supervisor training and researched other programs. Various training programs were attended or used including: LTAP, CTAP, Manual of Practice for an Effective Anti-icing Program, APWA Anti-icing/RWIS CD, AASHTO Clear Roads CD Series, and attending an APWA Snow Conference.
Since 2003 to 2011, the City invested about $250,000 in the program, including a $50,000 building addition. They recognized that the right equipment is the key to providing the flexibility to apply the right chemicals, in the appropriate amounts by the most efficient method.
Depending on conditions, Prior Lake keeps pre-mixed chemicals ready for use and bulk materials on hand. This allows the City to pre-mix and modify operations depending on weather conditions. Using the best available weather data for preparation and monitoring actual ground temperatures during operations is critical.
Equipment upgrades can be phased in over time. Prior Lake took seven years to fully upgrade the fleet. The new 5100/6100 controllers and new sanders can apply pre-wet material at rates down to 85 pounds per lane mile. Liquid application units can also apply at below 100 pounds per lane mile rates. Upgraded equipment includes:
Liquid anti-icing operations increased removal efficiency. The City found that applications are effective for 7-14 days after application, depending on the type of mixture and conditions. Equipment was also used for a liquid-only route with deicing application rates of less than 100 pounds per lane mile.
Efficient truck design and equipment including Elliptical Box, 200 gallons of Liquid Storage, Falls Salt Special Material Applicator, Force America 6100 Controller, and bed tarp allows for more efficiency with application rates of pre-wet salt as low as 85 pounds per lane mile.
Prior Lake had a reduction of average application rates from 500 pounds per lane mile of salt in 2005 lane to 200-250 pounds per lane mile using pre-wet salt in 2010.
This information was taken from the Six Cities Chloride Reduction Project.
The city of Centerville, after attending a winter maintenance workshop, collaborated with Lino Lakes, Hugo, Circle Pines, Lexington, and Columbus to purchase shared anti-icing equipment and to train the staff to use BMPs. The coalition was able to successfully apply for a Rice Creek County Watershed grant of 65,000 dollars to offset the costs. The new anti-icing equipment was used to apply liquid salt brine to 245 miles of paved roadways before the winter storms to reduce the need to apply salt during and after the storm. The training provided to the operators, reinforced the need to apply enough salt for public safety, but to avoid applying unnecessary amounts to pollute. The coalition plans on using the savings on materials to continue to fund the operational costs and program maintenance.
In the 2012-2013 winter season, the six participating cities reduced their salt use by 528 tons, or a 32% reduction based on the previous monitoring data. The six cities saved a combined total of $26,400 in a single winter, based on a conservative cost estimate of $50/ton of salt.
The information provided below is based on information presented at the awards ceremony at the 2013 Road Salt Symposium (Freshwater Society 2013).
In 2009, the Nine Mile Creek Watershed District (NMCWD) began a TMDL Analysis and Report process for the chloride impairment identified for the Nine Mile Creek. By 2010, they had prepared a draft TMDL report that called for a 62% reduction of salt application by the NMCWD MS4 cities, including Richfield. Along with other agencies, Richfield’s reaction to the reduction was the requirement was not only unreasonable, but impossible. They believed that public safety would be compromised and that the goal was too far to take seriously. However, the City eventually came to accept that they had to make efforts toward reducing salt usage.
The City Engineer learned that the NMCWD was working with Fortin Consulting and the LTAP to offer the free MPCA Winter Maintenance Certification Training. After attending the training the City Engineer found the training to be excellent. The entire snowplow operations staff was immediately enrolled in the next available training and all of the snowplow operators that plow parking lots have attended the MPCA Winter Parking Lot and Sidewalk Maintenance Training.
Despite the pride and effort that Richfield’s winter maintenance staff has in their work, the training showed them many ways to improve their operations. The education, along with the dedication of the staff, created a sense of urgency to change their practices and make the needed improvements. The changes needed were relatively small and simple to implement quickly
Richfield’s salt application process changes were:
These small changes reduced the amount of salt applied to roads by over 50%. It is projected this will improve over time, bringing the city closer to the TMDL of 62%. The Richfield operators have traditionally taken great pride in their work; the additional training provided them with the understanding of the importance of reducing salt for the environment and not just cost savings shown below.
1 The cost savings were based on the 2009-2010 price of salt.
This information was supplied from the city of Shoreview in 2015.
In 2006, the city of Shoreview stopped using a mixture of sand and salt and began using straight salt. This was the beginning of a continuous effort to reduce chloride.
Shoreview’s applicators and their supervisors each attend the annual “Snow and Ice Control Best Practices” training and are certified through the MPCA. The crew attends an annual meeting to discuss and review procedures and conservation methods. The operators are trained and allowed to make adjustments based on conditions and the pavement temperatures. The MPCA materials, guidelines, and BMPs have been successfully used throughout this effort.
A snow event begins with the city’s crew monitoring the surface temperature and road conditions. This information is critical to following their BMPs and application guidelines. This practice allows for preparation for the storm and the application of anti-icing to reduce the ice that requires treatment during and after the storm.
The goal of the anti-icing procedure is to apply calcium chloride to at least 28 lane miles of roadway before the storm to reduce the buildup of ice and allow for cleaner plowing. All of the city’s trucks are equipped with state-of-the-art spreading controls, pre-wetting tanks, and pavement sensors to ensure that each truck is calibrated and efficient. The use of the pre-wetting calcium chloride reduces the need for rock salt and minimizes the loss of salt from bounce or vehicle distribution. Pre-wetting allows the salt to be effective at lower temperatures.
The three-year average salt use for 2006-2008 was 786 tons and in the period of 2009-2011 the average amount of salt used dropped to 437 tons. The reduction continued during 2012-2014 to 444 tons. Although the tons of salt appear to increase, there were more snow and ice events during the 2012-2014 period. The total reduction of salt since 2006 is approximately 44%. The cost savings for 2014 is estimated at approximately 24,468 dollars.
This information was provided by Freshwater Society, 2014 Environmental Leadership Award on February 6, 2014.
St. Paul Street Maintenance has changed and updated its snow maintenance practices and equipment to reduce salt, increase driver safety and improve the service level. The city created its first Snow Plan in 2011 through the collaboration of the maintenance staff.
The following equipment has been upgraded:
Between 2012-2013, the following training was completed:
The city has had an average salt reduction of 30% per event over the past five years. The purchase of salt was reduced over the five years from 24,000 tons to 16,000 tons.
The information provided below is based on information presented at the awards ceremony at the 2013 Road Salt Symposium (Freshwater Society 2013).
The city of Waconia Public Services Department completes winter maintenance activities on 56 street center lane miles, portions of 14 miles of concrete sidewalk and 13 miles of bituminous trails.
Prior to the winter season, City staff attends an annual winter preparations meeting. They review the Winter Maintenance Policy, route assignments; discuss material use, and the service level expectations. All spreaders are calibrated for liquid and solid material applications. Calibration charts are prepared and placed in each vehicle for user review.
In 2010, the staff updated their 1999 “Snow and Ice Policy” to a “Winter Maintenance Policy.” The document title expresses a different, proactive approach to events. In the past, the city had a reactive approach to storms. The City changed from a 1:1 sand/salt mixture to straight salt and liquid anti-icing practices. Additional items reflected in the policy included:
By implementing calibration and equipment changes, the staff has been able to reduce materials rates of salt per-pound by 70%. Using pre-wetting practices and saving material by application rates based on weather and pavement conditions have saved 1.80 dollarsper-lane-mile and a yearly savings of 8,600 dollars.
As part of the winter maintenance practices for sidewalks and trails, the staff took the initiative to switch from hand-applied and truck-applied chloride products to liquid applications only. The staff conducts anti-icing and deicing activities as needed on sidewalks and trails leading to substantial savings. The staff obtained a “Local Operational Research Assistance Program” grant for 5,000 dollars. The research found a savings of 70% for activities related to recreational critical areas through the use of liquids for trails and sidewalks
The information provided below is based on information presented at the awards ceremony at the 2007 Road Salt Symposium (Freshwater Society 2007) and updated by Doug Lauer, a Landcare Supervisor with the University. The UMN Twin Cities Campus made changes to their winter maintenance program starting the winter of 2006. They began making their own salt brine and anti-icing and adopted several other salt reduction BMPs. The resulting reductions for each winter maintenance material are listed below in Table 10.
Twin Cities Campus – Winter Maintenance Improvements
Link to this table
Material | Tons/Year Used (1997-2005) | Tons/Year Used (2006-2008) | Tons/Year Used (2008-2014) | Reduction | Notes |
---|---|---|---|---|---|
Rock Salt | 775 | 262 | 40% | ||
Ice Melt (MgCl2) | 131 | 64 | 51% | Changed from MgCl2 to CaCl2 in 2008 | |
Ice Melt (CaCl2) | 131 (MgCl2) | 59 | 55% | ||
Sand | 1965 | 20 | 99% |
In addition to salt reductions, they invested about 10,000 dollars in new and saved 55,000 dollarsthe first year the BMPs were implemented. The UMN used an average of 1,965 tons of sand from 1997-2005; in 2006 to 2008, it was reduced to 18 tons. This is a 99% reduction. Between 2009 and 2014, the UMN used an average of 21 tons of sand in this five year period, showing a continuing decline.
The UMN continues to use brine to treat before the storm, as indicated in Table 10. The staff is aggressive with mechanical removal using blades and brooms. A change was made from magnesium chloride to calcium chloride because it mixes better with sodium and doesn’t clog their equipment when changing products. The product contains less corrosive beet juice.
Joe’s Lawn and Snow is a small lawn and winter maintenance company located in the TCMA. The following information was provided by Joe Mather, owner.
Joe’s Lawn and Snow plows and treats both sidewalks and parking lots. Prior to attending the MPCA Winter Maintenance Certification class, the staff relied on manufacturer recommended application rates and best judgment for application rates. Joe Mather attended the certification class in the winter of 2013-2014 and sent four employees. Joe and his staff were able to implement the practices learned in the first year.
Practices implemented included:
These changes, implemented for the last half of the 2013-2014 season, resulted in a reduction of salt by about 50% and did not reduce the level of service. Based on the 2014 cost of salt per ton, this saved Joe’s Lawn and Snow 770 dollars in material costs.
This page was last edited on 23 November 2022, at 16:13.