I figure it is time for a change of pace post on this blog. For the last little while I have gotten into some relatively heavy technical stuff that has scared some of my most faithful readers (including my mom) away. Today I am going to discuss something that is much more approachable and applicable to our daily lives in a post about water quality. The idea for this post comes from an unexpected visit I had this week from a salesman for a water treatment system company. The visit started with mis-direction, was filled with mis-information and ended with me realizing how easy it is for someone using the right combination of words to scare families into buying an expensive system they simply do not need.
The visit was preceded by an official sounding telephone call. Months ago my wife got a telephone call from someone purporting to be associated with the Township (we live in the Township of Langley) who asked her a bunch of questions about our water. Tuesday night we got a follow-up call from a woman who said she was following up on the survey. She talked to my wife and made it sound as if the Township had hired their company to come out and sample our tap water. There was no indication that this was a sales call but rather she made it sound like we were being asked to do our civic duty by allowing their professional to come into our house to do some testing. Since it was a rare night when we didn’t have any children’s sports scheduled, and I was going to be home, my wife suggested that they come that night and we scheduled a time. At the end of the phone call my wife was asked our occupations (purportedly for demographic purposes), she said she was a teacher and I was a Chemist. Now any sensible company would have had red flags flying upon hearing my profession (like the lawyer in the jury pool who gets tossed without any other consideration) but maybe the woman thought I was a pharmacist so who knows.
At the scheduled time a gentleman arrived at our door. He was soft-spoken and wearing a pair of khakis, looking every bit the part of an environmental technician (and I should know) with a clamshell briefcase full of supplies. He gave me a card with his company’s name (for the purpose of this blog I am not going to use the company or tester’s name as the point is not this person in particular but the approach in general) and we welcomed him in. The card indicated that the company was a “Gold Seal Approved – Canadian Water Quality Association Member” which sounded sufficiently official to belay our concerns. He efficiently set up his testing station and cleaned his supplies with a bottle of water marked as “reverse-osmosis water” (ROW) all the time chatting about water. I moved back to give him space (I didn’t want to interfere with his testing) and instead he invited my wife and I forward. First he pulled out a hand-held total dissolved solids (TDS) meter. A TDS meter measures the level of TDS in your water and is a pretty straightforward tool. He first measured his ROW water and got a reading of 4 parts per million (ppm) which is a very low reading consistent with a distilled/RO water. He then measured our tap water and got readings a reading of 14 ppm, he then re-filled the water and got a 21 ppm and started tut-tutting. At this point I started to tweak into the fact that this was not a Township water test as he didn’t have a notebook and wasn’t recording anything anywhere. Now as a Chemist who used to do this type of testing for a living (I now have technicians who do my testing for me) I can say TDS values from 14 to 21 from our tap is absolutely tremendous number. The Canadian Drinking Water Guidelines are 500 ppm (ref) and at 21 ppm I am almost ready to retire my Brita. The tester however was quite concerned and pointed out how our value was “elevated” I almost chocked when he used the word “high” at one point. He pointed out that the water system he uses can get your number down to single digits (as low as 1) which he made sound pretty significant. At this point I smiled to my wife as we knew this was no water test and we got ready for the sales pitch.
The next test was the addition of a single drop of “Agent #5” (I admit I might have the number wrong) which turned the water purple. Our water was darker purple which he informed us was a bad thing. He then cleaned his glassware and re-filled the two beakers (one with his water one with ours) and added two drops of our dish soap. He shook the two beakers vigorously and lo-and-behold his had more suds. He added two more drops of our soap to our water and shook it and the suds were still not as fluffy. He attributed this to the TDS in the water. In this he was almost right in that one benefit of reverse osmosis is that it softens water a tiny bit and anyone who has dealt with water softeners knows, the softer your water the better your soap bubbles. That being said, if your water is too soft it can seem almost impossible to wash the suds off your body. So now we have had three tests none showing anything slightly wrong with our water. He then moved to our soap pointing out that our dish soap was not organic and likely had sulfonic acids in it. How he knew is an interesting question as our dish soap is from a container without any labels, but even then sulfonic acids are a feature of detergents that are completely unspectacular. Soaps need surfactants to deal with oils and it is just one of many alternatives. It is like being made to fear your vinegar because it has acetic acid in it...for the non-chemist vinegar is simply a mix of acetic acid and water. He then informed me that the chlorine in municipal water mixes with sulfonic acid to make mustard gas, which of course, is chemically impossible.
His next line of discussion was the chlorine in our municipal water and how this chlorine can make people sick. He pointed out that when we shower we are exposed to chlorine gas. This is a common ploy and one that while chemically true is completely deceiving. I discussed the concept in detail in an earlier post: How Big and Small Numbers Influence Science Communication Part 2: Understanding de minimis risk how minimal concentrations of compounds are essentially ignored by your body. Except in exceptional cases, like when the municipality is flushing the lines with chlorine (which they announce in the papers), the amount of chlorine gas in your shower would not harm a fly, let alone a human. At this point it was clear to him he was losing us. I kept turning and smiling to my wife when he said something chemically impossible/improbable so he cut to the chase and informed us that he was a representative of a water treatment company and provided us with a quotation for a system at our water intake and a second system by our kitchen sink, total cost only $8000 and as a bonus they would supply us with all the soap (organic soap he said) for 5 to 7 years....I never figured out why it was such an imprecise number. He showed me the soap samples and the ingredient list looked no different from the list from your grocery store...although one of the soaps did include goat milk? He then told us about a recent stop where he had visited a $5 million mansion with a reverse osmosis system treating well water that had TDS levels of 140 ppm...for shame...for shame...and that he was going to convince them to buy a better system from him. As I mentioned above the water quality guidelines are 500 ppm so 140 ppm from well water is pretty darn good. After this discussion it was time to thank the representative for his visit and welcome him to leave.
Once the representative was gone, I had a sit-down with my wife who asked me about all the things she had been told. Having lived with me long enough, she knew that much of what he had said was wrong but did not know in what way. It struck me that this gentleman’s scientific sounding patter would likely sway the uninformed and could convince someone that they needed a water treatment system when all the data he presented proved that we had no use for such a system. A Brita water system would get our drinking water as clean as theirs and frankly leaving a pitcher of water in the fridge does just as good a job at getting rid of chorine as either their system or a Brita. We live in a society where we are constantly informed that everything around us is unsafe. Chemicals are not scary things, they make up everything around us. For a really easy read on the topic I would direct you to a post at “the Logic of Science” titled 5 simple chemistry facts that everyone should understand before talking about science. As for your drinking water? If you live in the British Columbia lower mainland and get your water from the Metro Vancouver water system then no you don’t likely need a reverse-osmosis system costing $8000 when a $1.50 water pitcher you leave in your sink will give you essentially the same quality water.