The late December 2021 snowfall that brought traffic, business and a host of other activities to a halt also tested Edmonds’ snow removal plan to the limit.

“At least we knew several days in advance that this was coming,” said Tod Moles, street and storm manager for the Edmonds Public Works and Utilities Department.  “It gave us the chance to gear up and be ready before the first flakes hit.”

Moles has seen a lot of snowstorms over his 25 years in this position and is personally proud of Edmonds’ commitment to an environmentally sound snow removal plan. But with two severe, multi-day snow events in less than a year, the time has come to take a critical look at how Edmonds deals with major winter storms, city officials say.

According to Acting Public Works Director Rob English, Edmonds’ snow removal standard operating procedure (SOP), adopted “around 2007,” continues to provide overall guidance for snow response (read the snow response SOP here). It calls for a phased approach, with the four action phases triggered by conditions varying from freezing temperatures to forecasts of snow to the onset of weather events. It also identifies which streets get first and second priority for clearing in the event of snow (see snow removal priority map here), and de-icing regardless of accompanying snow (see ice removal priority map here).

“The routes and priority streets were updated around 2011,” English added. “The plan and the priority maps haven’t changed since then.”

“The current plan provides a standard framework for snow response,” observed Moles. “But that said, each situation is different. Mother Nature didn’t look at the plan, and we need to stay nimble and adapt to the conditions at hand. It’s historically rare that we have snow events lasting five to seven days, but now we’ve had two of them in a row. It’s worrisome.”

Concerned that this might signal a shift to more extreme winter storms in the future, Mayor Mike Nelson has directed that Edmonds’ snow response plan be re-evaluated to ensure that it positions the city to best respond to whatever the future holds.

“I appreciate how hard our public works crews worked during the recent significant snow event,” said the mayor. “With these types of extreme winter weather events increasing every year, it is a priority to reevaluate our overall snow response to meet these new challenges. Our Public Works Acting Director Rob English has started this process with his team to assess what improvements need to be made to our city snow response plan.

“I have asked for an update in 30 days,” Nelson continued. “Part of their assessment will include hiring an expert to evaluate our snow response equipment, materials usage (liquid de-icer, sand, salt), training procedures and protocols for our snow response staff, an evaluation of our snow response maps, and produce an updated snow response plan.”

Like most cities where snow is an occasional event, Edmonds does not maintain a fleet of dedicated plows and other snow removal vehicles that would sit idle at other times. Rather, Public Works outfits its three utility dump trucks with plows, sanders and spreaders for deploying sand and chemical deicer. These are the same trucks that haul dirt, equipment, gravel, asphalt – anything that’s needed – at all times of the year.

During the December snow event, these vehicles worked full time in round-the-clock rotation, providing 24-hour coverage beginning Christmas night. It was an all-hands-on-deck event, with the full complement of 18 employees working 12-hour shifts (actually 13 hours to provide overlap during transition, Moles points out), plowing, sanding and performing other activities to keep streets clear. Many were out ahead of the freeze applying deicers to roadways to keep ice from building up on the pavement, only to return once the snow started falling with plows and sanders to keep critical arterials open.

“I can’t say enough good about the job our crews did,” added Moles. “During this entire event we kept our two hilliest and most critical arterials – Main Street and Puget Drive – open continuously. And I’d be remiss not to give a big shout-out to our fleet maintenance crews who maintain these vehicles – some of which have been in service for 20 years — in top operating condition and for performing critical repairs on the fly to keep the trucks rolling. We don’t have backup trucks, and when we’re in the middle of a major response we need to keep going.”

And with Edmonds’ hilly topography and maze of serpentine streets, plowing can be a challenge.

“It’s a misconception to think that a plow truck can go anywhere,” Moles pointed out. “They can get stuck too, and in the middle of a major event we can’t afford to have a truck out of service.”

Moles also stressed that another common misconception is that plows can just cut right down to the pavement and scrape it clean.

“We, like all our neighboring cities, have plows with rubber-surfaced blades over a ceramic core – not steel,” he explained. “These not only help maintain our street surfaces (steel blades would destroy our streets), but are much safer to operate. Hitting a manhole cover with a steel plow is like running the truck into a wall – very dangerous for the driver, not to mention damaging our equipment and taking the plow out of service just when it’s needed.”

Where Edmonds differs from our neighboring cities is in our strict use of environmentally safe chemical deicers.

In lieu of the traditional rock salt, Edmonds uses CMA (calcium magnesium acetate) to control snow on roadways. Inert and without deleterious environmental effects, CMA is the standard for Edmonds, and is specifically called for in the 2007 SOP. Edmonds purchases it in 1,000-lb. bags and mixes it with water before deploying it on street with sprayer trucks.

One big downside to CMA is cost. A ton of CMA costs $650. The same amount of rock salt? Fifty bucks.

It’s also trickier to use.

With salt, you just spread it and it melts the snow and ice, penetrating through to the roadway surface. But CMA does not penetrate well. According to Moles, it’s great if it can be spread prior to a snowfall (see Phase I of the SOP), where it will do a great job preventing the snow from sticking to the roadway surface. But after the snow has fallen and become compacted, it will tend to melt only the surface, which can leave roads very slippery (a detailed comparison of rock salt vs CMA is available here).

“Salt breaks up snow and ice better than CMA,” Moles explained. “But you also have to be careful with CMA – it can actually create a slicker surface in declining temperatures.  The best time to use CMA is before the snow starts to fall when there’s no rain ahead of it.  All it takes is a little bit of rain to wash the CMA away, and it’s all for naught.”

But the downsides of rock salt are arguably much worse, including accelerating the corrosion that causes steel bridges, pavement and other infrastructure to fail, and, for a city like Edmonds with salmon-bearing streams, poisoning the waters that are critical to the salmon’s life cycle.

According to an article published in the Columbia University Climate School’s State of the Planet, road salt is “a ticking time bomb for freshwater.” The article goes on to point out that salt levels in soils and aquifers nationwide “have been building up for years [as a] result of road salt spread decades ago which reached groundwater, and is only now slowly reaching surface waters,” adding that “once salt gets into the soil, or into a waterway, there really are no biological processes that will remove it.” It goes on to explain that “if runoff containing salt goes into a freshwater lake or stream, it will tend to sink towards the bottom, creating a dense layer that can inhibit gas exchange with the overlying water. This can lead to the development of low oxygen conditions that are detrimental to fish and other aquatic organisms.”

Locally, this could mean a potentially fatal setback to recent efforts to enhance salmon runs in our streams, restore the Edmonds Marsh, and other environmental initiatives.

“In the Northwest, the winter months are when salmon eggs and alevin are in the gravel in salmon-bearing streams,” pointed out Edmonds retired fisheries biologist and Edmonds Marsh advocate Joe Scordino. “Research has shown that higher salinity levels can prevent or interfere with the normal early development of salmon eggs, thus [we must use] caution in use of salt on roadways that drain into streams in the winter.”

Until last year, no rock salt at all was used on Edmonds streets, but according to Moles during the last two major snow events (February and December 2021) a very limited amount mixed with sand was used on Main Street and Puget Drive to keep traffic moving.

“We mixed it 3-1 with sand and adjusted the spreader chute to release the bare minimum,” explained Moles. “We had obtained 50 yards of it from the state. We didn’t use it all up in February, but kept some in reserve. That was all used during the December event. I begged the crews to go sparingly, and they were outstanding – all our priority roads remained open.”

And this exemplifies the challenges we face in developing an “Edmonds kind of” snow response plan that balances our community values and priorities with the need to keep streets open as winter snow events become more extreme. When does our need to maintain open streets justify environmental trade-offs? Do we allow limited use of salt, or do we tolerate less passable roads for the duration of a snow event?

Mayor Nelson recognized this in his call for a full review of our snow response plan.

“Edmonds has been in a leader in protecting our environment,” he said. “It is important we consider the environmental impacts with any snow/ice removal techniques that we adopt. Keeping our residents and streets safe is our top priority when winter weather hits.”

— By Larry Vogel