According to http://209.94.197.2/dec99/dec21/finance.htm Trinidad has found
(Mr. Assam is the Consumer Affairs Minister);

<quote>

After much suasion from several quarters, Assam last Friday named bottled
waters which had "unacceptable levels of heterotrophic plate counts'' based
on tests conducted by the Caribbean Industrial Research Institute (Cariri).

The plate counts, Assam said, "indicate the general cleanliness of the water."

</quote>

Hetertrophic plates are apparently bacteria (never heard of those either :-) );

http://www.who.int/water_sanitation_health/GDWQ/Microbiology/hpc.htm

Marilyn