The sources of drinking water (both tap water and bottled
water) include rivers, lakes, streams, ponds, reservoirs,
springs, and wells. As water travels over the surface of
the land or through the ground, it dissolves naturally occurring
minerals and, in some cases, radioactive material, and can
pick up substances resulting from the presence of animals
or from human activity. Contaminants that may be present
in source water include:
Microbial Contaminants, such as viruses and
bacteria, that may come from sewage treatment plants, septic
systems, agricultural livestock operations, and wildlife.
Inorganic Contaminants, such as salts and
metals, that can be naturally-occurring or result from urban
stormwater runoff, industrial or domestic wastewater discharges,
oil and gas production mining, or farming.
Pesticides and Herbicides, which may come
from a variety of sources such as agriculture, urban stormwater
runoff, and residential uses.
Organic Chemical Contaminants, including synthetic
and volatile chemicals, that are by-products of industrial
processes and petroleum production, and can also come from
gas stations, urban stormwater runoff, and septic systems.
Radioactive Contaminants, which can be naturally-occurring
or be the result of oil and gas production and mining activities.
Regulations: In order to ensure that tap
water is safe to drink, USEPA and the California Department
of Health Services (Department) prescribe regulations that
limit the amount of certain contaminants in water provided
by public water systems.Department regulations also establish
limits for contaminants in bottled water that must provide
the same protection for public health.
Important Health Information: Some people
may be more vulnerable to contaminants in drinking water
than the general population. Immuno-compromised persons
such as persons with cancer undergoing chemotherapy, persons
who have undergone organ transplants, people with HIV/AIDS
or other immune system disorders, some elderly, and infants
can be particularly at risk from infections. These people
should seek advice about drinking water from their health
care providers. USEPA/Centers for Disease Control (CDC)
guidelines on appropriate means to lessen the risk of infection
by Cryptosporidium and other microbial contaminants are
available from the Safe Drinking Water Hotline. Drinking
water including bottled water may reasonably be expected
to contain at least small amounts of some contaminants.
The presence of contaminants does not necessarily indicate
that water poses a health risk. More information about contaminants
and potential health effects can be obtained by calling
the EPA’s Safe Drinking Water Hotline (1-800-426-4791).
The Facts About Radon
Radon is a radioactive gas that you can’t see, taste, or
smell. It is found throughout the U.S. Radon can move up
through the ground and into a home through cracks and holes
in the foundation. Radon can build up to high levels in
all types of homes. Radon can also get into indoor air when
released from tap water from showering, washing dishes,
and other household activities. Compared to radon entering
the home through soil, radon entering the home through tap
water will in most cases be a small source of radon in indoor
air. However, radon is a known human carcinogen and breathing
air-containing radon can lead to lung cancer. If you are
concerned about radon in your home, test the air in your
home. Testing is inexpensive and easy. You should take remedial
action if your indoor air level of radon is 4 picocuries
per liter of air (pCi/L) or higher. Drinking water containing
radon may also cause increased risk of stomach cancer. There
are simple ways to fix a radon problem that aren’t too costly.
For additional information, call your State Radon Program
or call the EPA’s Radon Hotline (800-SOS-RADON).
