Bleach Soup
Feb. 12th, 2009 01:12 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
snousleYesterday we undertook a shock chlorination of the water system. For people with wells, it's not such a big deal, but tanks complicate the situation considerably. Our water is probably OK without it, but the spring is completely unprotected, and I wanted to make 100% sure that when the health inspector comes to test the water it comes out clean. Otherwise, he could totally shut down our operation.
There were a whole bunch of things that could go wrong. We had to avoid wasting excessive amounts of water, poisoning the stream (or our septic tank), ruining the carbon filter, or - worst of all - ending up with no drinkable water at all. I had a very careful checklist, and it turned out to be a fairly elaborate procedure with little room for error. We finally managed to get the whole system chlorinated, the potable tank emptied, and everything set up so that the lines to and within the house could disinfect overnight while the tank refilled with sterilized water.
One sticky point was that the potable water only empties down to about 5% of its capacity, so I didn't know how to get all the chlorine out after the treatment. However, John turned up a sump pump that was able to bring it to a nearly empty state. So we only had to chlorinate about 200 gallons of water, with just 150 gallons dumped into the ditch - less than a liter of bleach overall. I'm sure a few frogs bit the dust but that's about all.
Another thing that held it up was that in some of my initial tests, our chlorine test strips have turned out to be 10x too sensitive. 10 PPM registers at 100 PPM on the strip. I triple-checked all the calculations and that was the only thing I could conclude. Either that, or we somehow got a bottle of super-bleach with 50% chlorine, which is a chemical impossibility. I will have to ask the test strip manufacturer about this, since it's obviously a health hazard to think you have enough bleach when you don't.
A little bleach goes a long way! Bleach is at about 5% chlorine, or 50,000 PPM, while shock chlorination happens at 200, and anything over 10 PPM is completely undrinkable. (That's even too high for swimming pools.) I wanted to get the residual down to at most 1 after it was all over.
Everything went flawlessly. Almost. In the morning, I ran all the faucets until the strips showed nothing, and was pleased to find we had nice, fresh, chlorine-free water again.
So I go to make lunch - duck and rice soup, using some nice duck leg confit I'd made earlier. But something was very, very, very wrong. Then it hit me - d'oh! I'd overlooked the flushing of the whole commercial kitchen, and all the lines were still full of bleach! Wow, that was an awful experience. One tiny little sip of the broth, and I can't even get the taste out of my mouth with whiskey. Bleach plus organics makes a huge number of horribly carcinogenic compounds, but I don't think I tasted enough to actually cause a problem. Hopefully. I can't believe that a lifetime of weakly-chlorinated water isn't already worse than a half a teaspoon of bleach soup.
Amazing how even the most careful plans can fuck up just when you least expect it.
There were a whole bunch of things that could go wrong. We had to avoid wasting excessive amounts of water, poisoning the stream (or our septic tank), ruining the carbon filter, or - worst of all - ending up with no drinkable water at all. I had a very careful checklist, and it turned out to be a fairly elaborate procedure with little room for error. We finally managed to get the whole system chlorinated, the potable tank emptied, and everything set up so that the lines to and within the house could disinfect overnight while the tank refilled with sterilized water.
One sticky point was that the potable water only empties down to about 5% of its capacity, so I didn't know how to get all the chlorine out after the treatment. However, John turned up a sump pump that was able to bring it to a nearly empty state. So we only had to chlorinate about 200 gallons of water, with just 150 gallons dumped into the ditch - less than a liter of bleach overall. I'm sure a few frogs bit the dust but that's about all.
Another thing that held it up was that in some of my initial tests, our chlorine test strips have turned out to be 10x too sensitive. 10 PPM registers at 100 PPM on the strip. I triple-checked all the calculations and that was the only thing I could conclude. Either that, or we somehow got a bottle of super-bleach with 50% chlorine, which is a chemical impossibility. I will have to ask the test strip manufacturer about this, since it's obviously a health hazard to think you have enough bleach when you don't.
A little bleach goes a long way! Bleach is at about 5% chlorine, or 50,000 PPM, while shock chlorination happens at 200, and anything over 10 PPM is completely undrinkable. (That's even too high for swimming pools.) I wanted to get the residual down to at most 1 after it was all over.
Everything went flawlessly. Almost. In the morning, I ran all the faucets until the strips showed nothing, and was pleased to find we had nice, fresh, chlorine-free water again.
So I go to make lunch - duck and rice soup, using some nice duck leg confit I'd made earlier. But something was very, very, very wrong. Then it hit me - d'oh! I'd overlooked the flushing of the whole commercial kitchen, and all the lines were still full of bleach! Wow, that was an awful experience. One tiny little sip of the broth, and I can't even get the taste out of my mouth with whiskey. Bleach plus organics makes a huge number of horribly carcinogenic compounds, but I don't think I tasted enough to actually cause a problem. Hopefully. I can't believe that a lifetime of weakly-chlorinated water isn't already worse than a half a teaspoon of bleach soup.
Amazing how even the most careful plans can fuck up just when you least expect it.
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Date: 2009-02-12 09:36 pm (UTC)