Ha ha, well said geoffo,for future reference peeps may wish to...

Ha ha, well said geoffo,

for future reference peeps may wish to use the term "a layer of sediment that is not natural to that water body" rather than say "pollution". And can peeps also refrain from asking any questions that have been asked for 15 years, but for which no empirical answers seem to exist.

sorted that for u geoffo, we should get no more of those pesky questions that we cannot answer.

onwards and upwards peeps