JUST THE FACTS FOR CONSUMERS
ARSENIC IN YOUR DRINKING WATER
is arsenic;
Arsenic is a toxic chemical element
that is unevenly distributed in the
Earth's crust in soil, rocks, and
minerals.
How does arsenic get into my drinking
water?
Arsenic occurs naturally in the environment and as
a by-product of some agricultural and industrial
activities. It can enter drinking water through the
ground or as runoff into surface water sources.
How is arsenic in drinking water
regulated?
In 1974, Congress passed the Safe Drinking Water
Act. This law directs EPA to issue non-enforceable
health goals and enforceable drinking water
regulations for contaminants that may cause health
problems. The goals, which reflect the level at
which no adverse health effects are expected, are
called maximum contaminant level goals (MCLGs).
The MCLG for arsenic is 0 parts per billion (ppb).
The enforceable standard for arsenic is a maximum
contaminant level (MCL). MCLs are set as close to
the health goals as possible, considering cost,
benefits, and the ability of public water systems to
detect and remove contaminants using suitable
treatment technologies.
Why should I be concerned about
arsenic in my drinking water?
Although short-term exposures to high doses (about
a thousand times higher than the drinking water
standard) cause adverse effects in people, such
exposures do not occur from public water supplies
in the U.S. that comply with the arsenic MCL.
Some people who drink water containing arsenic in
excess of EPA's standard over many years could
experience skin damage or problems with their
circulatory system, and may have an increased risk
of getting cancer. Health effects might include:
* Thickening and discoloration of the skin, stomach
pain, nausea, vomiting, diarrhea, and liver effects;
* Cardiovascular, pulmonary, immunological,
neurological (e.g., numbness and partial
paralysis), reproductive, and endocrine (e.g.,
diabetes) effects;
* Cancer of the bladder, lungs, skin, kidney, nasal
passages, liver, and prostate.
What is EPA's standard for arsenic in drinking water?
To protect consumers served by public water systems from the health risks of long-term (chronic)
arsenic exposure, EPA recently lowered the arsenic MCL from 50 ppb to 10 ppb.
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JUST THE FACTS FOR CONSUMERS
What types of public water
systems must comply with the
standard?
The 10 ppb arsenic standard applies to all
community water systems. The standard
also applies to non-transient, non-
community water systems.
How will I know if there is
arsenic in my drinking water?
Every year, your community water system
sends you a consumer confidence report
(sometimes called a water quality report),
listing any levels of arsenic detected. EPA
also requires all community and non-
transient, non-community water systems to
give you public notice when their water
supply violates the arsenic standard. You will
be given information about what is being
done to correct the situation.
How much is 10 ppb?
10 parts per billion (ppb) of
arsenic in water means that
there are 10 molecules of
arsenic for every
999,999,990 molecules of
water. That is roughly
equivalent to a few drops
of ink in an Olympic-sized
swimming pool.
What is a community water
system?
A community water system is a system that
serves 15 locations or 25 people year-round,
including most cities and towns, apartment
buildings, and mobile home parks with their
own water supplies.
What is a non-transient, non-
community water system?
Non-transient, non-community water
systems serve at least 25 of the same
people more than six months of the year,
such as schools, churches, nursing homes,
and factories.
Should I have my water tested for arsenic?
If your water comes from a municipal or privately-owned water company
that has more than 15 service connections or serves 25 people more
than 6 months of a year, they are already testing for arsenic in your water.
If you have your own household water supply, you are responsible for
maintaining and testing it. Contact your local health department to find
out whether arsenic is a contaminant of concern in your area. Your state's
drinking water agency can give you names of laboratories that are certified
to test drinking water.
NSF International (www.nsf.org/certified/DWTU), the Water Quality
Association (www.wqa.org), and the Underwriters Laboratories, Inc.
(www.ul.com/water) web sites list certified home treatment units.
FOR MORE INFORMATION
Safe Drinking Water Hotline
1 -800-426-4791
Arsenic in drinking water
http://www.epa.gov/safewater/arsenic
Arsenic health effects
http://www.atsdr.cdc.gov/toxprofiles/phs2.html
Your private well
http://www.epa.gov/safewater/privatewells
Lh'HlHll SUCd
Office of Ground Water & Drinking Water
www.epa.gov/safewater
EPA816-F-07-002
March 2007
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