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Wrong Chemical Dumped Into Olympic Pools Made Them Green (arstechnica.com)
Z00L00K writes: [Ars Technica reports:] "After a week of trying to part with green tides in two outdoor swimming pools, Olympic officials over the weekend wrung out a fresh mea culpa and yet another explanation -- neither of which were comforting. According to officials, a local pool-maintenance worker mistakenly added 160 liters of hydrogen peroxide to the waters on August 5, which partially neutralized the chlorine used for disinfection. With chlorine disarmed, the officials said that 'organic compounds' -- i.e. algae and other microbes -- were able to grow and turn the water a murky green in the subsequent days. The revelation appears to contradict officials' previous assurances that despite the emerald hue, which first appeared Tuesday, the waters were safe." I would personally have avoided using the green pools, but that's just me. "Hydrogen peroxide is sometimes used in pools -- often to de-chlorinate them," reports Ars. "Basically, the chemical, a common household disinfectant, is a weak acid that reacts with chlorine and chlorine-containing compounds to release oxygen and form other chlorine-containing compounds. Those may not be good at disinfecting pools, but they still may be picked up by monitoring systems. Hydrogen peroxide can also be used to disinfect pools but must be maintained in the waters -- not a one-time dumping -- and can't be used in combination with chlorine." Apparently, the green water irritates eyes and smells like farts.
Not on the news in every part of the world. And it took a while from submission to presentation where the editor obfuscated the content as well, original submission here: https://slashdot.org/submissio...
The fact that someone screwed up is one thing, but it's good to also get some information on what the screwup was and the consequences of it - that it wasn't entirely safe from a health point of view. At least it didn't create mustard gas.
If builders built buildings the way programmers wrote programs, then the first woodpecker would destroy civilization.
It's not nearly as simple as that. In terms of outdoor water supplies, I'm not sure it's particularly dangerous. Bacteria break down quickly in tropical water, though viruses are a bigger problem. But there are plenty of nasty water supplies in other places. For example, there are brain eating amoebas that live in deeper water in the United States. While water treatment means human activities don't pollute the water like in Brazil, plenty of other nasty things can live there, including things that don't die as readily outside of the tropics.
As for the diving well, it's a mistake that shouldn't happen, but sounds like the result of human error. Can you trust pools in the United States to be sanitary? Human error and incompetence can occur anywhere. It might be a good thing that this happened in an outdoor pool in Rio, where at least the rapid growth of the algae quickly alerted everyone that something wasn't right. It's less likely that algae would have grown quickly in an indoor pool, which might have allowed harmful things like bacteria and viruses to grow more before it became obvious there was a problem. Once the algae bloomed, adding a large amount of chlorine is one of the recommended steps to treat the problem in any pool. I don't see why human error and incompetence are inherently less likely in, say, Beijing or London. It could happen in Indianapolis, where Olympic trials take place. Can you trust a hotel pool to be safe and clean? There was at least a lot of monitoring at the Olympics to quickly test for safety and then to act accordingly. I'd bet many hotel pool are far more unhealthy than the diving well ever became. Back in 2008, one in eight public swimming pools in the United States were immediately shut down after inspection because of unsafe water or other dangerous conditions.
Also, the chemical smell that pools sometimes get is actually from chloramines, which develop from the interaction of chlorine with things like bacteria. If a pool has a strong smell, it's quite possibly unsafe. And chloramines aren't safe, either. Thats also what forms when you mix ammonia and bleach.
As for my statement about public pools: http://abcnews.go.com/Health/Wellness/cdc-swimming-pools-pose-infection-risk/story?id=10711137
While the green algae blooming drew a lot of attention, I don't see this as being a result of incompetence from hosting the Olympics in Rio. I'd much rather swim in the diving well in Rio than take my chances with many public pools in the United States.
While I don't care what the Athletes themselves do I pretty much have to agree the Olympics are a huge money pit for their hosts. In the Sydney games for example the games not only failed to stimulate economic growth they effectively reduced consumption. At the end of the day the games ended up costing every Australian household around $400...
Since the "officials" had no knowledge of how the pool was treated, they cannot offer assurances that it's "safe." They just don't know.
Dumping in a lot of chlorine is not sufficient to sanitize a pool. The PH also needs to be in the proper range (7.2 - 7.8). The water also needs to be pumped through the filter for 8 - 12 hours a day (24 if cleaning up a green pool). The surfaces of the pool need to be brushed to move dead algae from the pool surface into the water (after which the filter will catch it).
The fact the pool turned green, yes. However, the actual reason for it (hydrogen peroxide being dumped in it) was only revealed today everywhere. In between then and now, it was pure speculation as to why the pools turned green, though most people suspected algae. Most people also thought it was a shortage of chlorine and muriatic acid causing the pH to rise, not that someone dumped a pile of hydrogen peroxide.
Of course, it isn't rocket surgery how to maintain the chemical balance of a swimming pool, and most pools generally err on the side of being over chlorinated than under to keep the nasties at bay.
Um, no. This is basically putting your fingers in your ears and yelling la-la-la-la-la to avoid hearing the actual science.
Pools are treated with hypochlorite, which is one way to kill bacteria. It's one measure, in addition to filtering systems. Hydrogen peroxide can also kill bacteria, but it isn't used with hypochlorite. The result is the production of water, oxygen, and sodium chloride. Instead of hypochlorite, you'd get chlorine ions in the water. Chlorine ions won't kill bacteria and algae.
Though algae can form in indoor pools, it's more common outdoors. Testing for chlorine in the water didn't reveal anything anomalous, probably because of testing for free chlorine instead of hypochlorite. The conditions allowed the rapid growth of algae, which turned the water green. If the testing didn't reveal anything anomalous, it's possible that the contractor responsible for maintaining the pool wouldn't have noticed. The algae made it blatantly obvious there was a problem. The response was to shock the pool with calcium hypochlorite, which would make it easy to remove the algae. This also increased the hypochlorite in the pool, making it safe again. The fart smell was hydrogen sulfide, a result of the algae. The irritation was from the large amount of hypochlorite used to shock the pool.
The algae caused officials to act, which probably mitigated any impact from microbes in the pool. I'm not convinced the water in the diving well was ever particularly unsafe.
One in every eight public pools inspected in 2008 in the United States was shut down from unsafe and unsanitary conditions. I'd bet that swimming in many public pools is far more like swimming in a toilet bowl than anything that ever happened in the Olympic pool. The real issue is the complete ineptitude of the IOC and their inability to get their story straight. That said, you're probably far more likely to get sick from swimming in a public pools in the United States than swimming in the diving well in Rio. I'd much rather swim in the diving well than a hotel pool, that's for sure.
Unfortunately, there are too many knee-jerk reactions like yours that are based on an ignorance of science.
Over the last 15 years, good chemists all over the world have been losing their jobs. Wages have been stagnant for 20 years. Those MBA types keep thinking any jackass can be hired to do the job. Well, this is what happens when you hire a jackass to do chemistry. You get green pools to put out for the whole freaking world to see. And you end up looking cheap and stupid. Well, us chemists are laughing our asses off while we stand in the unemployment line.
Ok, I'll plow into this.
Pool chemistry is, well, chemistry. And despite the offhand IOC statement that "chemistry is not an exact science", chemistry is science. And it's an excellent topic for /.
Maintaining my little 10,000 gallon play pool has been an interesting adventure;
- In Arizona, sunlight and temperature conspire to make pool maintenance a challenge; sunlight by itself both encourages everything you don't want in your pool (algae and bacteria for two) and decomposes chlorine, your most common disinfectant and algaecide.
- Cyanuric Acid (CYA), used as a chlorine stabilizer, also binds chlorine so that it is ineffective as a disinfectant etc. And it does not, itself, decompose easily or quickly. CYA is used in residential pools to simplify management (intermittent filtering and circulation mean chlorine levels would fluctuate without stablizer) and to reduce cost (burnt off chlorine requires adding more). Commercial pools don't typically need this, and indoor pools even less.
- Chlorine tablets (most commonly Trichloro-S-Triazinetrione) and much granulated chlorine (commonly Calcium Hypochlorite, so-called 'shock') contain CYA, and each bit you use adds CYA to your pool, eventually increasing the concentration to the point that it renders chlorine ineffective.
- Now you get to increase the amount of chlorine you use, also increasing the CYA, and the effect compounds itself.
- The solution is to drain the pool, reducing the concentrations, and add your chlorine sources to restore the level, starting the cycle again. Yes, you do.
- I now use an erosion dispenser that doesn't float, and it works insanely well. CYA levels of 110ppm force my free chlorine levels to test 1ppm, but the pool is clear and free of algae and detectable contaminants.
- Commercial and Olympic pools would never use erosion dispensers. I expect them to use gas systems. And using CYA is wrong for these pools because they should be constantly dispensed, constantly monitored, and chlorine expense is
So my challenges are different than those at the Games, but similar in some details.
I tried liquid chlorine (Sodium Hypochlorate, Clorox without the perfume and higher concentrate) for a while, but it's not as effective and requires constantly measuring and pouring, whereas tablets dissolve (erode, hence those floaters called erosion dispensers) without intervention or attention beyond filling it when they are gone. I gave that up without buying or trying to build an automated dispenser, just not worth it yet.
The problem at the Olympics has been well discussed, but from my view as a residential pool owner:
0. They let the chemistry get out of hand. I expect such a pool, at such an event, to be constantly monitored. Inexcusable.
1. Having let it get out of hand, a proper shock by adjusting the pH and alkalinity, using, for instance, a disodiumsalt of ethylenediaminetetraaceticaciddihydratediammoniumsulfate (this is a proprietary product that works), then Calcium Hypochlorate or other chlorine should have cleared the pool overnight. It does mine, even in 90 overnight temps, the only difference being quantities. A filter aid would clear the milky residue that we saw on TV. This process can be used to successfully clear a pool in 12 hours.
2. Using Hydrogen Peroxide wasn't just a mistake, it was malpractice, and I would fire the nimrod that decided that. It is incompatible with chlorine, period. Huge mistake.
3. the filters should be running constantly, not because of demand but because of the critical nature of maintenance. These are used throughout most of the day, are critical to the Games, and no excuses. Similarly the disinfectant systems. It's not about the cost, it's about the money.
4. Each pool should have had its own filtration and disinfectant systems. Of course.
I give the maintenance teams a grade of F. Just incompetent in these pools, and no such failure is acceptable.
deleting the extra space after periods so i can stay relevant, yeah.