Thread by @estolte

Council starting its debate on the road salting and calcium chloride pilot project.
Goal was to reach bare pavement last year with various techniques. Calcium chloride provider Tiger Calcium is in the audience for chemistry questions 😏
edmontonjournal.com/news/local-new… #yegcc #yegtraffic

Chemistry 101 - Salt works by disrupting the crystal structure of water molecules as they form ice, melting it, officials tell council.
A corrosion inhibitor works by creating a film on the metal to protect it while the salt still melts the ice.
#yegcc

Did the city see any impacts from the increased road salt on the city fleet? No, says director Janet Tecklenborg.
"We have seen no significant and measurable impact to date." #yegcc

But there was definitely an impact to the city budget ... they saved roughly $5 million by not using so much sand, says Tecklenborg. #yegcc

City officials have learned better when to use which product, says Tecklenborg. At roughly -20 C, the calcium chloride no longer works. Sand works at that point, but is ineffective on roads where the speed is greater than 50 km/h. #yegcc

Who else uses calcium chloride on their roads? Pretty much everyone, say officials. This is not an exhaustive list. Many cities have been using this for 20 years. #yegcc

So what did Edmonton actually use on the roads last year? City officials just presented this graph.
They've always been using some calcium chloride but both it and traditional salt increased last year in an attempt to get to bare pavement. #yegcc

.@MikeNickel2019 selected the item but declines his turn to ask questions. "I'll just be moving cancelation of the pilot project."
So we know that's coming. Will council support it?
#yegcc

.@_TimCartmell points to a line in the city report that suggests Edmonton used nearly five times as much traditional salt last year than the year before.
So the damage people are seeing could be from regular salt, no? he asks. #yegcc

Sorry, that was nearly five times as much as two years ago. #yegcc

"Are we telling people when we asked if we should continue this that we're using 4.8 times as much salt as two years ago?" says @_TimCartmell.
City officials say it's closer to 1.5 times more than some other high-snow years. Salt-use is higher but variable. #yegcc

"I don't think we're being forthright," says @_TimCartmell.
City's Gord Cebryk says they don't know what salt is causing the damage for people but the goal is to reduce all salt across the board while still getting to bare pavement. #yegcc

Council getting a nice lesson in chemistry. The inhibitor works because molecules have one part with a charge that attaches to metal, 2nd part that has no charge. That part sticks out like a tail and protects the metal, says the visiting chemist. "It gives like a skin." #yegcc

This is new "best-in-class" inhibitor Edmonton will be using for the first time, says the chemist.
Most cities using calcium chloride are using the same inhibitor that Edmonton used last winter, say officials. #yegcc

.@bevesslinger asks about the city's motivation for trying to reduce the sand.
They had a bad audit on their sand recycling program a short while back, and now throw it out each winter.
That's one factor among others for reducing sand use, says city's Gord Cebryk. #yegcc

.@AndrewKnack says for years Calgary has been using double the amount of salt Edmonton used last year.
"What have we learned from Calgary?" Are their residents/industry partners as worried? #yegcc

"I'm feeling a little bit of governance anxiety," says @MichaelWalters, wondering about how deep council wants to go into this fairly nerdy chemistry lesson.
The original intent was to seek bare pavement to get safer roads with less sand.
#yegcc

If Edmonton cancels this project, what does the city do. Go back to sand? says @MichaelWalters. "We had this dirty sludge over the city all winter."
City's Gord Cebryk says yes, there are limited options. They can plough as much as possible but you have to apply something #yegcc

Is it conclusive that Edmonton's salting pilot project is contributing to the private corrosion residents are complaining about? says @MichaelWalters.

Yes, it can contribute. It opens the door, says the chemist. #yegcc

City officials says their tests indicate concrete that's been cured properly should be safe. It should not see increased spalling from the road salt.
But everything has pros and cons, she says. #yegcc

"I don't know if we have a communications problem or a corrosion problem," says @Scott_McKeen. Can you actually see corrosion that quickly?
Yes, says the chemist, if you have an older car without the protective coatings. But this new inhibitor should protect everything. #yegcc

.@Scott_McKeen seems concerned about how much the city is still learning. "We could create more of a financial burden on the city than this is worth."

But that's it for the debate now. They're breaking for lunch and coming back for a vote later this afternoon. #yegcc

Council ready to vote on the road salt and calcium chloride pilot now.

@MikeNickel2019 has his motion to cancel the project on the floor. Cancelling it means the city would have to find that $5 million in savings elsewhere. #yegcc

.@ben_hen asks how the city would handle freezing rain if calcium chloride and other increased road salt isn't available to it.
City says that's still unclear.
@AndrewKnack asks about increased sidewalk treatment around seniors centres. That's part of this pilot. #yegcc

.@JonDziadyk suggests Edmonton is making decisions on this without having enough data and information. He suggests they can cancel the pilot now and revisit it after studying what's used in other cities again.
City say that means no "in field" data locally. #yegcc

.@MichaelWalters says he won't support cancelling the pilot project.
The city is addressing concerns by adopting the new corrosion inhibitor. He's frustrated research wasn't done earlier but it's being done now.
They asked for a safer, cleaner way of dealing with snow.
#yegcc

"I also think we should keep on going with this," says @ben_hen. Edmonton's climate is changing, including more freezing rain. "Being adaptable is the real key. Adapting to the next winter rather than responding to the last."
Keeping more tools available is key. #yegcc

"Would I prefer to be in an accident of have my vehicle corrode?" says @ben_hen. He prefers corrosion.
"I'm scared if we step back now, we're going to be right back here in 3 to 4 more years. ... I don't think this is the time to be taking tools out of the tool box." #yegcc

"We've had a communication gap right from the word go here," says @_TimCartmell.
People wondered why there was corrosion. City told them they used less sand. That doesn't answer the question.
The answer is that the city used much more salt. #yegcc

"My concern with not proceeding with a pilot is, winter started on Saturday and we don’t have a plan," says @_TimCartmell.
Says he doesn't know how to vote. There were too many unanswered questions and council is reduced to researching other city's practices on the fly. #yegcc

"We have heard a lot from seniors across the city," says @AndrewKnack. They wait up to a week for sidewalks to be sanded so they can cross the street to update a prescription.
If they end the pilot today, status quo or major budget increases are the only options. #yegcc