Slurry store volume calculation

With some lateral thinking there is a connection between Youtube and EnCompass and slurry storage.

What is the formula for calculating the volume of a cylindrical slurry store?

Visit this link and find out:  http://www.youtube.com/watch?v=bON3X7UpFRE and watch for a simple and clear explanation.  Much easier than the explanation in the DEFRA NVZ leaflet 4.

Remember to reduce the actual height by 0.3 m to allow for freeboard as a safety margin.

Of course this assumes you know the radius of the slurry store.  Since it is probably hazardous to find the centre of the store and run a tape measure to the sidewall.  Walk around the store to measure the circumference and use this online calculator: http://www.csgnetwork.com/circlecalc.html

OK, that is roughly how a teenager studying for GCSE's would approach the problem.  For those of the BM generation:

Take one pencil, a used envelope and use these formulae:

Storage Volume = PI * r2 * (H - 0.3m)
And
r = C / (2 * PI)

where
PI = 3.14
R = radius in metres
R2 = radius squared
H = height in metres
C = circumference in metres
BM = Before Microsoft