# computing well volume for sanitation?

**URL:** <https://boards.straightdope.com/t/computing-well-volume-for-sanitation/641252>\
**Category:** Factual Questions\
**Created:** [November 16, 2012, 11:23pm UTC](https://boards.straightdope.com/t/computing-well-volume-for-sanitation/641252 "2012-11-16T23:23:12Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![cedman](https://avatars.discourse-cdn.com/v4/letter/c/da6949/32.png) [@cedman](https://boards.straightdope.com/u/cedman)\
**Post date:** [November 16, 2012, 11:23pm UTC](https://boards.straightdope.com/t/computing-well-volume-for-sanitation/641252/1 "2012-11-16T23:23:12Z")

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Hello,

I need to sanitize our well but the instructions are for a 6" casing and our well has a 24" casing.

So, if a 6" well casing holds 1.47 gallons of water, how many gallons of water does a 24" well casing hold?

(I just KNOW that the figure I came up with is WRONG so I’m turning to the math minds here. Wouldn’t want to poison us by using too much calcium hypochlorite!)

Thanks!

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<div class="post-metadata">

**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\
**Post date:** [November 16, 2012, 11:41pm UTC](https://boards.straightdope.com/t/computing-well-volume-for-sanitation/641252/2 "2012-11-16T23:41:18Z")

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Volume of a cylinder = ∏r^2 \* H

Assuming H (height) is a constant, a 6" (diameter) casing holds 3.14 (3\*3) = 28.26H units and a 24" casing holds 3.14 (12 \* 12) = 452H, so 16 times as much water.

ETA, 23.52 gallons