Importance of not saving first of rainfall.

CactusCritter

19th January 2007 - 07:23 AM

http://www.physorg.com/news88268999.html

During the period from 1937 to mid 1944, I lived with my parents in a rural environment where we depended on rainwater for sustenance. I was startled when I first saw the title of this article. It never occurred to me that some folks would not divert the first period of a rainfall away from their cistern.

My parents would never thought of not diverting that first of a fresh rainfall. I"m astonished that doing so was/is not the norm everywhere.

adoucette

20th January 2007 - 06:13 PM

Was it an automatic system to divert the initial rainfall?

I can think of several simple designs to accomplish this such as a container on a pivot that has to fill up to a certain level before the opening to the cistern is exposed to the flow. The container could be designed to have a slow leak such that it would automatically reset itself before the next rain.

Arthur

kaneda

22nd January 2007 - 07:46 AM

I would have thought it obvious that rain from a roof would contain all the pollutants that had been on it. However if it falls into a rain barrel and is left for a few days to settle, pollutants would remain at the bottom and if you just took water from the top, it should be pure. The barrel would need emptying out occasionally to prevent build up of pollutants.

adoucette

22nd January 2007 - 06:45 PM

A number of pollutants would be soluble and so letting the water sit would not help.

Arthur

kaneda

23rd January 2007 - 11:28 AM

Add orange juice to a glass of water and leave it a few hours and you'll find the orange juice has all sunk to the bottom. Brownian motion will stop it settling completely but the top half of the glass is orange juice free.

ChaosTheory

23rd January 2007 - 02:00 PM

QUOTE (CactusCritter+Jan 19 2007, 07:23 AM)

During the period from 1937 to mid 1944, I lived with my parents in a rural environment

Good lord, how old are you? no offense intended i just find being over 80-90 years (as specified) is quite astounding and very commendable.

adoucette

25th January 2007 - 07:51 PM

QUOTE (kaneda+Jan 23 2007, 07:28 AM)

Add orange juice to a glass of water and leave it a few hours and you'll find the orange juice has all sunk to the bottom. Brownian motion will stop it settling completely but the top half of the glass is orange juice free.

You are talking about a suspension, not a SOLUTION.

Dissolve Salt in water.

Let sit for eternity.

Salt will remain in solution.

Arthur

kaneda

27th January 2007 - 08:27 AM

adoucette. So how many poisons which will dissolve in water do you keep on your roof? Just about everything involved is going to be a suspension, starting with dirt settling quickly and things like lead more slowly.

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