by Michael Arny, P.E., LEED EB, President — Looking ahead to the winter season, it is important that facilities managers pay attention to their de-icer purchasing choices, especially for buildings that are earning or maintaining certification under the LEED Operations + Management (O+M) rating systems. A recent LEED Interpretation has redefined the requirements for LEED-compliant de-icers.
Updated LEED Interpretation for De-icers
LEED Interpretation 10146, which clarifies the requirements for deicing products that are compliant under Sustainable Sites credit 2: Building Exterior and Hardscape Management Plan, was substantially updated on January 1, 2015. LEED Interpretation 10146 now reads as follows:
“Projects may use one of the following compliance paths to achieve the de-icer portion of the snow and ice removal requirements for the credit addressing: Building Exterior and Hardscape Management Plans.”
De-icer Compliance Path 1:
Only use de-icers that contain 100% calcium magnesium acetate.
De-icer Compliance Path 2:
- Demonstrate that environmentally preferred de-icers were used at least 20% of the time during the performance period, measured by weight, volume, or cost. Environmentally preferred de-icers are defined as:
- De-icers that contain less than 5% sodium chloride, calcium chloride, magnesium chloride, potassium chloride, potassium acetate, ammonia-based products, and ferrocyanide products.
- Implement a de-icer quality assurance monitoring plan during the performance period to track ongoing de-icer use and record its effects for every snow event:
- Monitoring could include: if de-icer was applied prior to snow events, if areas were shoveled prior to de-icer application, the amount of snow over the season, the temperature when de-icer was applied, the time for snow to melt, etc.
- Include a plan to phase out all de-icers that are not environmentally preferred within 3 years.
The new requirements apply to all projects registered after January 1, 2015, under any version of the LEED O+M rating system, including recertifications. For projects that may be using SSc2 as an Innovation credit path in a Building Design + Construction application, these requirements also affect the required building exterior and hardscape management plan. The requirements are applicable internationally, as well as to projects in the United States.
What Does this Mean for You?
The de-icing product you used last year may not be compliant this year.
Any de-icer that contains more than 5% sodium chloride, calcium chloride, magnesium chloride, potassium chloride, potassium acetate, ammonia-based products, and ferrocyanide products is not considered environmentally preferred. You will not qualify for this credit if it is used more than 80% of the time.
De-icers that contain less than 5%, in total, of these substances are considered environmentally preferred. However, if you use such a product, you must also track its use and its effects after every snowfall. This is a more onerous task than simply recording how much product you used each month. Additionally, you will have to plan to phase out your use of all non-preferred de-icers within three years.
Your alternative is to switch now to a product containing 100% calcium magnesium acetate (CMA).
How CMA Works
Rather than melting snow and ice, CMA prevents snow and ice from adhering to surfaces, allowing it to be cleared away more easily.
CMA is best applied before, or in the early stages of, a snow event. Since it does not run off, it has to be reapplied less frequently than some other de-icers. Because it is used differently than traditional de-icers, you may have to retrain your staff in the use of CMA.
Impacts on Surroundings
CMA is biodegradable and will not burn the surrounding vegetation. It is also less corrosive than de-icers that contain chlorides, but can still damage asphalt and concrete.
CMA comes with a much higher price tag than some other deicing products. For example, it costs about twice as much per pound as sodium chloride (rock salt).
The Bottom Line
If LEED certification or recertification is on the agenda for your building, make sure you have thought through how you plan to meet the de-icer requirements.