Arsenic Fact Sheet - Culligan Aqua-Cleer Owner's Manual

Arsenic
Arsenic (abbreviated As) is found naturally in some well water. Arsenic in water has no
color, taste or odor. It must be measured by a lab test. Public water utilities must have
Fact Sheet
their water tested for arsenic. You can get the results from your water utility. If you have
your own well, you can have the water tested. The local health department or the state
environmental health agency can provide a list of certified labs. The cost is typically
$15 - $30. Information about arsenic in water can be found on the internet at the US
Environmental Protection Agency website:
www.epa.gov/safe water/arsenic.html.
There are two forms of arsenic: pentavalent arsenic (also called As (v), As (+5), and
arsenate) and trivalent arsenic (also called As (III), As (+3), and arsenite). In well water,
arsenic may be pentavalent, trivalent, or a combination of both. Special sampling
procedures are needed for a lab to determine what type and how much of each type of
arsenic is in the water. Check with the labs in your area to see if they can provide this type
of service.
Reverse osmosis (RO) water treatment systems do not remove trivalent arsenic from water
very well. 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) may not convert
all the trivalent arsenic. If you get water from a public water utility, contact the utility to find
out if free chlorine or combined chlorine is used in the water system.
The Aqua-Cleer system is designed to remove pentavalent arsenic. It will not convert
trivalent arsenic to pentavalent arsenic. The system was tested in a lab. Under those
conditions, the system reduced 0.050 mg/L (ppm) pentavalent arsenic to 0.010 mg/L (ppm)
(the USEPA standard for drinking water) or less. The performance of the system may
be different at your installation. Have the treated water tested for arsenic to check if the
system is working properly.
The RO component of the Aqua-Cleer system must be replaced every 3-5 years to
ensure the system will continue to remove pentavalent arsenic. The component
identification and locations where you can purchase the component are listed in the
installation/operation manual.
The system has been tested for the treatment of water containing pentavalent arsenic (also
known as As (V), As (III), or arsenate) at concentrations of 0.050 mg/L or less. This system
reduces pentavalent arsenic, but may not remove other forms of arsenic. This system is
to be used on water supplies containing a detectable free chlorine residual or on water
supplies that have been demonstrated to contain only pentavalent arsenic. Treatment with
chloramine (combined chlorine) is not sufficient to ensure complete conversion of trivalent
arsenic to pentavalent arsenic. Please see the Arsenic Fact section of the Performance
data Sheet for further information.
60