I have a degree in microbiology, albeit an old one, so I can't help but comment when such things as Cryptosporidium and water treatment arise.
On August 2, 2013, the Baker City Herald "Editorial Board" issued an editorial opinion, What's next with city's water, that recommended the city choose filtration over UV treatment, stating
"But in the wake of a week in which so many people were afflicted with stomach cramps, diarrhea and other unpleasant symptoms, in which restaurants and other businesses suffered during a busy weekend, we believe that extra cost is worth it."OK Herald, lets see the cost/benefit analysis. When McDonalds shut down for three days, I was told that Taco Time did a boom business. A neighbor I spoke with came down with Crypto, but he favors UV treatment.
The reasons given for the Herald's opinion were:
But UV is not as effective as a filtration plant in removing viruses, UV has no effect on chemicals, and a UV system would not protect the water from dirt and ash that could foul streams were a wildfire to burn in the city’s watershed.They also tell us:
The extra capabilities of a filtration plant come at a cost of perhaps $15 million, compared with an estimated $2.5 million for a UV system.There was no other discussion of costs, nor any reference for the source of their figures, or why their objections were relevant.
Then, after this very incomplete accounting, they put out a poll, What's Baker City's best water treatment option, as if everyone is informed, because, well, the Herald has informed us!
As I write, the vote stands, after 33 hours, as 59.8% in favor of filtration as the best option and 31.4% in favor of UV treatment. Only 102 people have voted, which I'm sure the Herald would agree, is not a number large enough to represent the 10,000 plus residents of Baker City. Perhaps all they had to go on was the Herald's recommendation. Why do they do these unscientific polls during a period of crisis right after they have issued an uninformative opinion that misleads the public? Kind of like asking Americans what they think of the passing something like the Patriot Act right after 911. These polls are almost completely worthless as gauges of actual, well thought out, public opinion, but I guess it gives people something to do and gives the Herald more web page hits while gathering support for their ill-advised notions.
And how is one to take the question? Does "best" mean the option that will do the job of treating Crypto while being one that we can afford, or does "best" mean the option that will possibly result in purer water than UV will provide (even though we will play hell paying for it)?
That is a problem, especially if the opinion they give to their few thousand readers is in error or incomplete. So let's "unpack" their information and reasons for recommending filtration.
There are three relevant questions:
What do we really need given the current and foreseeable conditions?
What can we afford given the the city's and the city resident's financial situation?
What is politically acceptable given the answers to the first two questions?
Do we want or need a water treatment system that can deal with every conceivable threat to human health, even when they don't currently exist in the watershed, and if we do, can a community struggling to finance other pressing infrastructure needs such as sewage treatment, streets, and aging water and sewer lines afford it? Do we need a Cadillac when a small hybrid car or Geo Metro will provide a solution to our problems? The Herald doesn't really address the question of whether we can afford it.
The Herald tells us that:
"UV is not as effective as a filtration plant in removing viruses"OK, so what? The Herald admits the city has a "long history of providing pure water." That water comes from a somewhat protected city watershed where human viruses are not a problem. Our watershed is not a source, such as the Colorado River, that has water passed through many communities and pastures where human viruses might be introduced to become a problem. Current conditions do not indicate that human viruses are, or will be a problem. They do indicate that Cryptosporidium is a problem, so we need a system like UV to treat it.
[Update 8/7/13: Turns out that while UV treatment for viruses may not be as effective as a pricey membrane filtration plant, the National Drinking Water Clearing House says "UV light effectively destroys bacteria and viruses" at the proper doses. See: Tech Brief--Ultraviolet Disinfection
For a more complete understanding, see: Section 13 Ultraviolet Light (p.258) in the EPA's LONG TERM 2 ENHANCED SURFACE WATER TREATMENT RULE TOOLBOX GUIDANCE MANUAL]
The Herald tells us that:
"UV has no effect on chemicals"OK, so what? Our last water quality report (2010-2012), and many before it, provides testing results that show chemicals, including nitrates, nitrites, trihalomethanes and halocacetic acids are far below the acceptable level--barely detectable.
The water quality report also states that:
There were "approximately 29 synthetic organic chemicals tested for and not detected."
There were "approximately 21 volatile organic chemicals tested for and not detected."
"The 2012 hardness value for untreated water was 75 PPM [parts per million = mg/L]" [barely out of the 0 to 60 PPM soft water category] I.E., our water is almost soft, not very mineralized by "calcium and magnesium, and by a variety of other metals." That's a good thing when you use UV treatment.
Levels for iron, manganese and flouride were all well within acceptable levels.
For more see: Interpreting Water Test Reports
Would levels of chemicals rise in case of a catastrophic fire? Yes, periodically, in which case we could switch to the well water we are using during the Crypto crisis, which would be safer when UV treatment is installed.
"a UV system would not protect the water from dirt and ash that could foul streams were a wildfire to burn in the city’s watershed."True, but both sand and ceramic filtration units can be overwhelmed by the same, and a complicated, yet supposedly effective, activated carbon and membrane filtration system could cost anywhere from $18M to $25M or more, 6 to 8+ times as much as a $3M UV system. [Update 8/7/13: (AND) membrane filtration "requires prefiltrations for surface water—may include removal of turbidity, iron, and/or manganese. Hardness and dissolved solids may also affect performance." So membrane filtration prefiltration would also be affected by dirt and ash from a wildfire. ] [Update 8/16/13: the city of Pendleton uses a flocculation tank] According to a 2009 engineering report I posted yesterday (See also Table 2 of the report), membrane filtration would cost something like 25 times as much to maintain as would a UV system! We would also be able to use the paid for well system for catastrophic fire emergencies (as in a drought--thank former Public Works director Fleming I believe), and we are following the recommended guideline for fuels reduction in the watershed which helps to prevent catastrophic fire. Over time, as budget allows, we could also create settling tanks or basins to let any sediments settle out prior to treatment.
The Herald tells us:
"The extra capabilities of a filtration plant come at a cost of perhaps $15 million, compared with an estimated $2.5 million for a UV system."
The Herald has been very consistent in reporting that a filtration plant will cost us $15 million. I would like to know where that figure comes from. The same 2009 engineering report I posted yesterday put the cost at 17.7 million dollars and that was four years ago. Those kinds of costs tend to go up--like everything else.
Is spending 18 to 25 million dollars for a Cadillac membrane filtration system, instead of a get-the-job-done $2 to 3.1M UV system going to be politically acceptable to the citizens of Baker City? Not if they are allowed to vote on it in an actual election--but now people are in crisis mode and we we'll not likely get a vote.
As a quibbling former microbiologist, there is another thing I'd like to mention. The Herald published an article today in which they reported statements from the senior state epidemiologist, Dr. Bill Keene.
The Herald says that Dr. Keene said “I’m pretty sure mountain goats have never been tested (for crypto).” I doubt that he said that, as the most easily found academic report (See Table 2), which I found on Google right after the Crypto outbreak had been reported (and sent to Councilor Coles last night), says that both mountain goats and humans are a minor host for one species of Cryptosporidium, that is, Cryptosporidium muris. Doesn't mean that the state will ultimately find that our furry friends are the "scapegoat" but it does seem to infer that they are a possibility, as I indicated days ago.
Oddly, the Herald chose to quote a passage from the same article that said "According to a 2004 article in Clinical Microbiology Reviews, crypto species "originating from wildlife... are mostly not human pathogens" instead of pointing out Table 2 which clearly states that both humans and mountain goats are a minor host for Cryptosporidium muris.
Additionally Dr. Keene confirmed my statement in the August 2nd blog that "These anecdotal reports seem to indicate that the number of cases in Baker City is far higher than the number of reported cases, quite possibly in the hundreds" when Dr. Keene told the Herald that "the total cases 'could easily be in the hundreds.'”