I am interested in finding out the "equivalent original water-sample volume"
that is examined by labs performing the IFA for cryptosporidium. This value,
I believe, would be equal to (original water sample vol.) (fraction of packed
pellet that was floated) (fraction of floated sediment that was actually
examined by IFA), or simply the (F V R) value presented in the EPA ICR
Microbrial Laboratory Manual.
I would be most interested in hearing from anyone testing raw (source),
finished and backwash test samples. I realize that the actual volumes will
vary somewhat depending upon turbidity. However, preliminary calculations
suggest approx. 10L for raw, 50L for finished, and 5L for backwashes samples.
Does this seem correct???
"Don't precipitate more than you can resuspend"