T&T: Watermaker suggestions and experiences?

[Bob Austin]

I think a little "medical" clarification is in order in reference to John's
suggestion that:
 "And, if there's fecal matter in the seawater, a membrane will not remove
the danger. "

A water maker will remove the E coli and any other bacteria--the pore size of
the membrane is such that virius, let alone bacteria will not get thru it. Any
harbor which has faecal contamination runs the risk of the bacteria growing on
the supply side membrane.  It is basically a mass effect.  Standards are
related to the number of colonies of E. Coli cultured in a lab. E coli are
measured because they are relitatively easy and cheap to grow and generally
are found in most faecal material and are a general measurement of
contamination.

There are hundreds of E. coli strains and most are relatively harmless,
causing illnesses such as traveler's diarrhea only when consumed in
exceedingly high numbers. A notorious exception is E. coli strain 0157:H7, an
emerging pathogen that produces a powerful toxin and can cause severe illness.
There is a reasonable possibility that the toxin can cross the membrane.  The
0157:H7 strain is apparently what is causing the current spinach illness and
death.

I concurr, that a watermaker should not be used down stream of a head (I made
sure that my intake was on the opposite side of the boat)--and in a harbor
with a number of boats.  E coli don't live a long time in salt water, but with
enough--such as a crowded harbor--there is a risk.

Bob Austin