Yesterday the Salem City Club learned how officials at the City of Salem are planning to prevent a repeat of last year's horrendous toxic algae infestation in the water supply.
Horrendous, because city officials delayed notifying people about the cyanotoxins that had entered the water supply following a toxic algae bloom in Detroit Lake. This led to a lot of anxiety among both vulnerable populations and the rest of the citizenry that largely could have been avoided with more transparency from city staff.
City Manager Steve Powers was appropriately contrite in his opening remarks, before he introduced the speakers who would describe the details of improvements to the Geren Island water treatment facility on the North Santiam River.
"Last year was humbling for me," Powers said.
The principal speakers were Heather Dimke (Public Works Department) and Jude Ground (water treatment expert with the Carollo company). Lacey Goeres-Priest (Water Quality Supervisor) and Brian Martin (city engineer) chimed in during the Q&A period.
I came away impressed with how the City of Salem has learned from its 2018 mistakes, and has come up with expensive, but necessary, upgrades to the current water treatment system (which basically is slow sand filtration basins using a biological means to remove pathogens).
The central piece of the improved system will be ozone treatment that's projected to come on line in Spring 2021 at a cost of $40 million. A Statesman Journal story, "Salem spending $75 million to protect drinking water from toxic algae," describes $35 million in additional enhancements that weren't discussed at the City Club meeting.
This slide shows the main components of the ozone treatment system. Note that the ozone is destroyed before drinking water reaches consumers.
However, for a number of years my wife and I had a small scale ozonator as part of our well-water treatment system (our untreated water is very high in iron). Sometimes water in our house would have lots of tiny bubbles, when an ozone release valve wasn't working properly. We suffered no ill effects.
In fact, one of the City Club presenters joked that ozone in water makes people feel good. Sadly, I don't recall that happening to me, though I recall ozone having a sort of fresh small, like before a thunderstorm (when ozone can be transferred to ground level from high up).
What ozone does, basically, is enhance the ability of the current water treatment system to deal with toxic algae and other noxious stuff. I don't recall how this happens in enough detail to describe it accurately. The following slide shows how the ozone treatement fits into the current system.
It isn't completely clear why toxic algae in becoming an increasingly prevalent problem -- not only locally, but elsewhere in the country. Higher water temperatures and nutrient run-off from forest fires are likely culprits, both arising from global warming, which unfortunately isn't going away anytime soon.
So city officials are wisely planning for the long-term. Yes, 2018 was the first time toxic algae entered Salem's water system. But almost certainly it wouldn't have been the last time absent the improvements to the water treatment system.
Pleasingly, we were told that the City of Salem now has the equipment to test for toxic algae on site. This will give one-day results for water samples rather than the previous three days. And the Oregon Health Authority has issued rules for toxic algae testing, notification, and such that didn't exist in 2018.
A poignant part of the City Club presentation came in the Q&A portion.
A man said that he had gone blind in one eye at the same time the toxic algae cyanotoxins were reported in the Salem water supply. He seemed to believe the blindness was caused by ingesting toxic algae.
That's possible. However, we need to remember that in a city Salem's size many people are suffering from new medical maladies every day. Just because they occurred during the toxic algae infestation doesn't mean cyanotoxins were the cause.
That said, I deeply sympathize with this man, since he and many others continued to drink city water that contained toxic algae during the period between the time it entered the water supply and the time city officials notified the public of the problem. From what was said yesterday, this will never happen again.