Results and evaluation for winter parking lot and sidewalk maintenance
Results and evaluation for winter parking lot and sidewalk maintenance

Information: We are in the process of migrating the Winter Parking Lot and Sidewalk Maintenance manual to the Minnesota Stormwater Manual. You can access a pdf version of the maintenance manual here. Other changes and updates to information on salt management will be posted in the What's new page in the manual. Information on road salt and water quality can be found on MPCA's website

The first winter maintenance training and certification workshops were held in 2005. After holding several classes, it was determined that a training manual was needed.

The Winter Parking Lot and Sidewalk Maintenance Manual was written in 2006 and the training classes using the manual started in the winter of 2006-2007. In order to evaluate the effectiveness of the training, three class exercises were created. These exercises show potential rate reductions, potential change in practices, and evaluate the training program. The results from the in class exercises were compiled at the end of the 2007-2008 winter season and are shown below.

Potential Changes

In 2007-2008, 345 people attended 14 Winter Parking Lot and Sidewalk Maintenance Workshops and filled out the forms used to evaluate the course. The summary of all the exercises is given below.

Rate Reduction

95% of attendees discovered the need to either reduce the amount of material that used, or to not use that material at all.
96% of attendees who used rock salt found that a need to reduce the application rates.
24% of all attendees used sand or salt/sand mix. It was discovered to be using the wrong material.
62% Average potential reduction in salt application rates.
20% - 89% Range of potential reduction

Best Management Practices (BMP)

Attendees were given a survey about the use of BMPs. Out of the recommended BMPs:

Before training: 31% of BMPs were already being used.
After training: 76% BMPs will be used in the future (as stated by participants).

Evaluation

Recommend class to colleagues? 93% yes
Was this class useful to you? 87% yes
Do you think you will be able to reduce the environmental impacts of the winter maintenance activities as a result of attending this class? 79% yes

Comments from those attending class:

It’s about time people got concerned about our water. Thanks for your work
Real world examples by people using these methods brings integrity to the presentation
Awesome job! I can see the wheels turning in people’s heads
Spread the word fast. This information is too important!
I am very surprised to learn so much about a subject that I thought I knew

Example interviews documenting actual changes

Following the winter season, follow up interviews were conducted to learn more about the winter maintenance changes made since training. The individuals interviewed had attended the training and volunteered to be part of our follow up research on the effectiveness of the training class. Several examples of these interviews are included below.

School District of Superior Wisconsin - Michael Soderlund - Maintenance Worker

Michael Soderlund attended the Parking Lot Training in October, 2007. After the training, many new successful changes were implemented. Overall, the District of Superior reduced their total use of deicers. One of the biggest steps forward was the production of their own brine. Michael said that everything is currently working well and there is no marked reduction in quality. Many District of Superior workers were initially hesitant about the new practices, but after a few tries they realized that the new methods work just as well or even better. The material application rates were greatly reduced, especially in the middle school and high school. The actual reduction rates are given below.

Rates:

2006-2007 - The district used 294 bags of ice melt (50 lb. bags); The total was $2,320.48 .
2007-2008 - The district used 196 bags of ice melt; The total was $1,552.32

Reduction in ice melt use: 33.3% Reduction in cost: 33.1%

University of Minnesota (UMN) - Twin Cities campus - Jim Weber - U of M Facilities Management

Over the past few years, the UMN recognized the need to become much more environmentally conscious with winter maintenance and storm water management. They made many changes in their snow removal program; two key areas were employee training and calibration of equipment. By increasing awareness of proper application rates, they were able to significantly decrease the amount of deicing chemical used. They started an aggressive anti-icing program with liquid magnesium chloride for their sidewalks and salt brine for the streets and loading docks. Pre-storm applications were extremely successful in reducing the bond of snow and ice to walks as well as giving them more response time on the front end of snow events. They focused on mechanical removal of snow as their first line of defense and they have changed the main deicer for walks from a blended material to straight magnesium chloride. They dramatically reduced the sand in their sidewalk and street program which has saved them time and money in spring clean-up and long term savings are expected in storm sewer maintenance. Small amounts of sand are still used as pattern indicators for their sidewalk trucks and for use during extreme cold weather. The numbers speak for themselves:

Material # 1 – Rock Salt

1997 - 2005 average: 775 tons of salt
2006 - 2008 average: 462 tons of salt
Net Average Reduction: 313 tons
Percent Reduction: 41%
Material Cost: $48.53/ton
Amount Saved: $15,193 average per year (2006 – 2008)

Material #2 – Ice Melt (Magnesium Chloride - MgCl2)

1997 - 2005 average: 131 tons
2006 - 2008 average: 64 tons
Net Average Reduction: 67 tons
Percent Reduction: 51%
Material Cost: $410/ton
Amount Saved: $27,470 average per year (2006 – 2008)

Material #3 – Sand

1997 - 2005 average: 1965 tons
2006 - 2008 average: 18 tons
Net Average Reduction: 1,947 tons
Percent Reduction: 99%
Material Cost: $8.30/ton
Amount Saved: $16,160 average per year (2006 – 2008)

Net-Work Services Company (NSC) - Bob Rush – Director of Operations

NSC is a national facility management company that services commercial properties in 22 states. NSC’s responsibility is to manage all building services which include hiring and managing winter maintenance contractors. While working in his prior role as Regional Manager for Minnesota and North Dakota, Bob Rush required all of his Minnesota winter maintenance contractors to be trained and certified on the best practices. As Director of Operations he has implemented a regional training program based on the Minnesota program. This allowed NSC to expand the best practices training to all winter maintenance contractors in cold weather states. Bob has taken many steps to reduce the impacts of winter maintenance and to improve the safety of his operations

Bob required all suppliers in the seven county metro area to switch to a standardized treated salt for parking areas. He helped calibrate all truck mounted spreading equipment to ensure they were not over-applying the deicer. Bob required all Twin City Metro and Duluth area suppliers to switch to a mag/hex for sidewalks. This standardized the deicer which helped the suppliers determine the correct application rates per sq. ft. based on temperature and location of the sidewalk.

He requested that all Twin City Metro suppliers attend the MPCA snow training program. He rewarded the suppliers that were able to show their certifications. NSC held regional training sessions with all contractors, reviewed best practice for snow removal, and discussed the proper techniques and timing for deicer application. Bob requires preseason re-training of large suppliers to refresh them on the best practices. He expanded the material that was developed by the MPCA and trained his 14 Regional Managers on best practices, impact on the environment, and the need for continual training. They, in turn, introduced the training material into the larger markets such Salt Lake City, Denver, Omaha, and Boise.

They eliminated sand use in Minneapolis and Denver and continue to educate the maintenance contractors on the impact that sand has on the environment. In the first year of the program, NCS reduced deicer use by 15-20% in parking lots and by 20-25% on sidewalks. They hope to see additional reductions in the amount of wasted material by continuing to help the teams understand the use of technology and best practices. Bob developed a working group to continue to research better practices and material with the goal of reducing deicer use and our impact on the environment.

Joe’s Lawn and Snow - Joe Mather - Owner

Joe’s Lawn and Snow is a small company located in the Twin Cities area. Joe attended the certification class in the winter of 2013-2014 and sent four employees. The changes were implemented for the last half of the season. They normally would have expected to use 20 tons of salt and only used 9 tons.

Prior to attending the class, they relied on application rates listed on the deicers and their best judgment to determine how much material to apply and did not calibrate their equipment. They learned a lot in the class and implemented many practices in their first year. Practices implemented included:

Purchased new spreader
Calibrated equipment
Made a “bowl” to catch any excess salt at spinner and reuse this
Made modifications to spreader to get more even spread and prevent salt piles
Reduced application rates
Tested application rates and results and kept refining
Purchased hand-held and truck mounted temperature sensors
Use temperature to help determine rates and materials
Identify drainage patterns and appropriate snow storage areas prior to winter
Use sediment traps to contain solids in runoff and they clean out manholes
Experimented with anti-icing using liquids and will continue to experiment

They were not able to reliably calibrate and adjust their old spreader so they purchased a new one. He plans to add mud flaps with pockets to prevent salt from going all over the truck and catch extra salt which they will reuse. They tested areas in parking lots to determine the best application rates. Before winter, they mark the edges of their parking lots with blue poles and used a different color to indicate where snow should be stacked. They have a covered salt storage area on one of their properties. It is a 20 x 30’ concrete walls and “tarp-type” top. It has a subfloor and a capture drain. It was a $20,000 investment. They had this prior to training. They do spring and fall sweeping.

They reduced their application rates by about ½ and then adjusted them up based on results as needed. With the changes made, they were able to reduce their salt usage by about 50% without reducing their results.

Cadwell Lawn and Landscaping - Charles Cadwell – Owner

After attending the Parking Lot Training in 2005, Charles Cadwell’s company examined their procedures for applying salt and deicing chemicals at Ridgedale Center and found areas that were candidates for improvement. Practices in previous years included using salt rather carelessly and applying it to attempt to keep snow from accumulating during a storm. As such, it was quite common to apply 12 to 14 tons of salt during a given storm. Since training, they examined their practices and have taken measures to reduce usage of salt products.

They reduced the speed setting on our auger to slow the feed rate of salt to the wheel. At the same time, they maintained the speed of the wheel and that made for better dispersion of the salt (more even dispersion of salt and greater coverage in a given load).

They inspected the truck tailgate because in previous years, they had a problem with spillage that resulted in "piles" of salt being dropped at random during turns or when hitting potholes or speed bumps. They found gaps between the tailgate sander and the truck bed that they filled with weather stripping. That forced all salt to be fed through the auger and baffle so that spillage was eliminated. That further increased the coverage per given load that was achieved.

Based on the information provided in training, they no longer apply salt or other chemicals during a storm. Salt is applied after the snow has been mechanically removed. The one exception to this is where some material might be needed to provide traction and permit traffic safety at stop signs or on slopes. In these situations, the materials are applied only sparingly after plowing is done.

Average salt usage for a given snow event is now five to six tons. That is based on the number of loader buckets put in the truck where one bucket is considered to be one ton (Ridgedale does not have a scale). That form of measurement is standard for what they did in previous years and from one contractor to another.

They were able to further reduce salt applications the winter of 2007 -2008 by educating the customer on the mechanical removal being the major step and only when that is complete is it reasonable to apply salt to the pavement. The mall was very receptive to only using salt when absolutely necessary. Supporting this approach, they were also able to maintain good performance in terms of the number of slip-and-fall incidents that occurred due to ice or snow. That supported the approach of using mechanical removal and then salt application as a standard process.

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Results and evaluation for winter parking lot and sidewalk maintenance Results and evaluation for winter parking lot and sidewalk maintenance

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