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Lead
in Drinking Water
EPA estimates that more than 40 million people in the United
States drink water contaminated by lead at concentrations
higher than the federal standard of 15 micrograms per liter
(or parts per billion — ppb). Most of this contamination
comes from the lead used in old pipes and plumbing fixtures;
as water sits in these pipes and fixtures, lead leaches into
it. Although federal regulations banned the use of lead in
pipes and other plumbing fixtures in 1986, lead in drinking
water can still be a problem in homes with plumbing installed
prior to that date. Drinking water from the tap in very new
homes may also contain lead if brass faucets and fittings
were used.
* How does lead get into drinking water?
* How do you know if your water contains
lead?
* What health problems does lead cause?
* What is EPA doing to regulate lead in drinking
water?
* What can you do?
How does
lead get into drinking water?
Lead is found in both public and private drinking water. The
metal contaminates drinking water by either entering source
water (ground water or surface water) or by corrosion of lead-bearing
pipes and plumbing fixtures. The latter is the primary source
of lead in drinking water except in areas where lead is mined
and smelted or where steel is manufactured.
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Many pipes and plumbing fixtures manufactured before 1986
contain lead, and water can cause the pipes to corrode and
leach lead into water standing in the pipes. The longer the
water sits in the pipes, the more lead it contains. Grounding
electrical equipment to water pipes – a common practice
– can increase corrosion. Unfortunately, lead contamination
from household plumbing goes undetected by public water utilities
because they cannot monitor for contamination once water leaves
the treatment plant.
Lead in source water is not a very widespread problem. According
to EPA, 88% of the lead mined and smelted in the U.S. comes
from seven mines in southeastern Missouri. Other areas where
lead and copper are mined are Arizona and Montana. An EPA
study performed between 1987 and 1993 indicates that close
to one million pounds of lead was released to water during
that six year time span. The largest releases during this
six year interval occurred in Ohio and Indiana, home to many
steel manufacturing plants. Lead releases to water were also
found in Illinois, Tennessee, Utah, Missouri, Texas, Wisconsin,
and Arizona.
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How do
you know if your water contains lead?
Lead is difficult to detect in water because it has no smell,
taste, or color. Your water might contain lead if your home,
but particularly your plumbing and water pipes, was built
or installed prior to 1986. Lead pipes are dull gray in color
and are soft enough that they easily scratch with a house
key.
Your water utility is required to notify you if your water
exceeds the regulated limit for lead. Between 1993 and 1995,
EPA required water utilities to sample water from household
taps twice a year and analyze it for lead content. If lead
was present above the 15 ppb standard in more than 10% of
the homes tested, the utility had to continue to monitor household
water for lead twice a year.
But the best way to detect lead in your tap water is to have
it tested by a laboratory. Tests costs between $20 and $100
typically. If you use well water, you should also have your
water tested by a laboratory. Look under "Water Analysis"
in the Yellow Pages for a lab near you, or contact your state
or local health department. Some local health departments
test private well water for free. Look under the government
listings in your phone book for their number.
If you call a water testing lab, be sure it is certified by
your State. You may call your State Certification Officer
to get a list of certified water testing labs in your state.
Click here to find out how to contact your State Certification
Officer.
Remember: A water test will only tell you what is in your
water that day. Many pollutants or public water treatment
plant failures can occur intermittently (e.g., during spring
runoff) and not necessarily the day your are having your water
tested.
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What health
problems does lead cause?
Ingestion of lead contaminated water can cause both short-
and long-term health problems. Short periods of exposure to
lead at levels above the 15 ppb federal standard can cause
problems with physical and mental development in children;
slight deficits in the attention span, hearing, and learning
abilities of children; and slight increases in blood pressure
in some adults.
Over the long term, exposure to lead over the federal limit
can potentially cause stokes, kidney disease, and cancer.
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What is EPA
doing to regulate lead in drinking water?
In 1974, Congress enacted the Safe Drinking Water Act. Under
this law, EPA is mandated with determining safe levels of
chemicals, which may cause health problems, in drinking water.
These levels are referred to as maximum contaminant level
goals – MCLGs. Using these levels as goals, EPA is also
required to set enforceable limits, called maximum contaminant
levels (MCLs), which become the national primary drinking
water standards for regulated chemicals.
For lead, EPA set a MCLG of zero because the agency believes
that lead contamination at levels higher than zero could cause
potential health problems. However, given present technology
and the cost of achieving this goal, the agency initially
set the MCL at 50 ppb.
In 1986, as part of the Safe Drinking Water Act Amendments,
Congress passed what is known as the Lead Ban. This ban requires
that lead solder, pipes, or flux in drinking water systems
be "lead free." "Lead free" is defined
as not more than 0.2% lead in solders and flux, and not more
than 8% lead in pipes. This ban was effective in all states
in June 1988. As part of the rule, public water utilities
must identify and provide notice to customers that may have
lead contaminated drinking water.
Since lead contamination typically occurs when water corrodes
household lead-bearing pipes and fixtures, water utilities
have a difficult time detecting it. Instead, EPA requires
water utilities to control the corrosiveness of their water
if the level of lead at home taps (determined by the 1993-95
survey described above) exceeds the lead standard. In 1991,
EPA lowered this level from 50 ppb to 15 ppb. This new standard
became effective in 1992.
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What can
you do?
If you think your drinking water may contain lead, or if you
are concerned about the possible health effects of contamination,
you should consider the following options:Install a filter
at the "point of use" (i.e., under your sink, on
the countertop, or at the faucet) that is certified by the
National Sanitation Foundation for lead reduction.
OMNI's undersink filters — CBF3 and OT32, countertop/faucet
mount filters — LN3 and WP1, or water cooler filter —
WCF1, are NSF certified for lead reduction.
Flush your tap water until it becomes as cold as it will
get (about 5 to 30 seconds if you have used the faucet recently;
2 minutes or more if the water has been sitting in the pipes
for over 6 hours). The more time water has been sitting in
your pipes and plumbing, the more lead it may contain. Also,
only use COLD water for drinking and cooking. Hot water will
leach more lead into it.
Purchase bottled water, but be sure this water had been adequately
treated. This is a more expensive and not necessarily effective
option
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