Comments on: Agua Non Potable

Question: Agua Non Potable

yankeefog — Thu, 29 Sep 2005 07:55:13 -0800

Many lavatories on trains have signs warning that the water in the sink is not safe to drink. If it's not clean enough to drink, am I really making my hands cleaner by washing with it?

By: horsewithnoname

horsewithnoname — Thu, 29 Sep 2005 07:59:31 -0800

It is if you've got poop on your hand.

By: cyphill

cyphill — Thu, 29 Sep 2005 07:59:50 -0800

I'm pretty sure it's because they used lead piping, which would cause perfectly clean water to be poisonous but would not effects its cleaning ability that much. I wouldn't take a bath in the stuff though.

By: DevilsAdvocate

DevilsAdvocate — Thu, 29 Sep 2005 08:06:55 -0800

Soap is not safe to eat; do you therefore conclude you shouldn't wash with it either?

By: taumeson

taumeson — Thu, 29 Sep 2005 08:07:56 -0800

on an airplane i saw readouts for "black water", "grey water", and "clean water"

i made the following assumptions:

clean water - brand new water out of storage. may be potable.
black water - contaminated water
gray water - recycled, like they use on the lawns here in tampa. it's been filtered to get particular matter out and most bacteria, but it's still not safe to drink because of chemicals and some small bacteria.

so on the trains it's probably recycled.

By: Pollomacho

Pollomacho — Thu, 29 Sep 2005 08:08:27 -0800

It's because the tank that the water is kept in may contain microbes. Those microbes may make you sick, but they aren't as bad as the ones on your poopy hands or on the hand rail you touched or your shoe laces that you just tied, etc. The train people don't want to be liable if you decide to risk drinking the water, so they put up a warning.

The soap you use will also help to lift them and the particles they hang out on off of your hands.

Unless water is REALLY dirty or contaminated, washing your hands in it is always better than not.

By: anastasiav

anastasiav — Thu, 29 Sep 2005 08:14:55 -0800

gray water - recycled, like they use on the lawns here in tampa. it's been filtered to get particular matter out and most bacteria, but it's still not safe to drink because of chemicals and some small bacteria.

Nope. Grey Water.

Black water probably has human waste in it. Grey water is water that has been used for dishes, shower, sink, washing, laundry -- it normally has some detergent in it and possibly particulate food matter as well. Clean water is just what it sounds like.

By: spicynuts

spicynuts — Thu, 29 Sep 2005 08:17:27 -0800

clean water - brand new water out of storage. may be potable.
black water - contaminated water
gray water - recycled, like they use on the lawns here in tampa. it's been filtered to get particular matter out and most bacteria, but it's still not safe to drink because of chemicals and some small bacteria.

Obviously you've never owned a Winnebago. ;)

Anastasiav has the correct definittions.

By: Pollomacho

Pollomacho — Thu, 29 Sep 2005 08:18:17 -0800

Incidentally, a teenager in the US saw water being loaded into planes from a tank labeled "non-potable" and decided to test the water himself. He tested samples from dozens of flights and found only a couple that met drinking water standards. He turned his results over to the EPA who forced airlines to put warnings on their lavatory sinks.

It has to do with the unsealed tanks.

By: Optimus Chyme

Optimus Chyme — Thu, 29 Sep 2005 08:32:19 -0800

That's really cool, Polomacho. Any links?

By: goethean

goethean — Thu, 29 Sep 2005 08:54:48 -0800

may be potable.

Speaking of which, why do we call drinkable water "potable"?

By: Pollomacho

Pollomacho — Thu, 29 Sep 2005 08:59:12 -0800

I was just looking for some links! His name is Zach Bjornson-Hooper. Apparently this same kid is working on an energy source derived from the growth of e. coli bacteria.

Here's a google cache of an article on him.

By: desuetude

desuetude — Thu, 29 Sep 2005 09:18:08 -0800

Speaking of which, why do we call drinkable water "potable"?

Because potable means "fit to drink."

[Middle English, from Old French, from Late Latin pMtbilis, from Latin pMtre, to drink, from pMtus, a drink.]

All liquids are "drinkable."

By: Aknaton

Aknaton — Thu, 29 Sep 2005 09:28:22 -0800

All liquids are "drinkable."

Glass? Silly Putty?
Just hasslin' you, now that the OP question seems to be answered.

By: yankeefog

yankeefog — Fri, 30 Sep 2005 04:44:01 -0800

Thanks, Pollomacho. Your reward for giving such helpful answers is you get asked a followup question.

The article you linked to included the following:

Skinner suggested that airline passengers who have weakened immune systems avoid drinking airline water, coffee and tea, and use bottled water instead. Those people also should avoid using airline water to wash their hands, added Benjamin Grumbles, the agency's acting water director.

I realize this is directed at people with compromised immune systems--but it does seem to imply that if the water is contaminated, you are better of NOT washing your hands with it... Does that contradict your original answer, or am I just confused?

By: ikkyu2

ikkyu2 — Fri, 30 Sep 2005 14:26:36 -0800

Well, if you take a huge dump and smear coliform bacteria from your crap all over your hands, now your hands are covered in coliforms.

Where did those bacteria come from? Inside your body, that's where. That suggests to me that it's probably not such a big deal if you're exposed to them.

Other people's bacteria, though - look out, immunocompromised guy.