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Arsenic (As) is a naturally occurring contaminant found in many ground waters. Arsenic in water
has no color, taste or odor. It must be measured by an arsenic test kit or lab test.
Public water utilities must have their water tested for arsenic. You can obtain the results from your
water utility contained with in your consumer confidence report. If you have your own well, you
will need to have the water evaluated. The local health department or the state environmental
health agency can provide a list of test kits or certified labs.
There are two forms of arsenic: pentavalent arsenic (also called As (V), As (+5)) and trivalent
arsenic (also called As (III), As (+3)). In well water, arsenic may be pentavalent, trivalent, or a
combination of both. Although both forms of arsenic are potentially hazardous to your health,
trivalent arsenic is considered more harmful than pentavalent arsenic.
RO systems are very effective at removing pentavalent arsenic. A free chlorine residual will
rapidly convert trivalent arsenic to pentavalent arsenic. Other water treatment chemicals such
as ozone and potassium permanganate will also change trivalent arsenic to pentavalent arsenic.
A combined chlorine residual (also called chloramine) where it does convert trivalent arsenic to
pentavalent arsenic, may not convert all the trivalent arsenic in to pentavalent arsenic. If you get
your water from a public water utility, contact the utility to find out if free chlorine or combined
chlorine is used in the water system.
This Premier reverse osmosis system is designed to remove up to 98% of pentavalent arsenic.
It will not convert trivalent arsenic to pentavalent arsenic. Under laboratory standard testing
conditions, this system reduced 0.30 mg/L (ppm) pentavalent arsenic to under 0.010 mg/L (ppm)
(the USEPA standard for drinking water). Actual performance of the system may vary depending
on specific water quality conditions at the consumer’s installation. In addition to the independent
laboratory standard testing conditions Premier has conducted additional field testing on our
reverse osmosis units to determine trivalent arsenic reduction capabilities. Based upon Premier
field testing, it has been determined that the RO units are capable of reducing up to 67% of
trivalent arsenic from the drinking water.
The RO membrane component of this Premier reverse osmosis system must be maintained
according to its recommended maintenance cycle. Specific component identification and ordering
information can be found in the installation/operation manual maintenance section, by phone at
1-800-752-5582 or online www.premierH2o.com
Arsenic Fact Sheet
