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Home > Environment
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Lead in Water Information
Frequently Asked Questions (FAQ)
About Drinking Water and Lead
Note: Some of the information contained in this document reflects best
available, but evolving scientific, health, and policy on lead. As additional
information becomes available, it will be updated.
A. Regional Sources of Drinking Water
- Where does my drinking water come from?
The Washington metropolitan region gets nearly 90% of its drinking water from
the Potomac River. This supply is further augmented by water from the Patuxent
and Occoquan Rivers, Goose Creek (a Potomac tributary), Lake Manassas (tributary
to the Occoquan), and groundwater. A relatively small percentage of the region
obtains water from individual groundwater wells.
Three major water supply agencies treat about 95% of the metropolitan region’s
drinking water: the Washington Aqueduct Division of the U.S. Army Corps of
Engineers, the Fairfax County Water Authority, and the Washington Suburban
Sanitary Commission. Several other agencies treat the remaining 5% of the
water, including the City of Fairfax, Frederick County and the City of Frederick,
the Town of Leesburg, the City of Bowie, City of Rockville, and several small
utilities that provide water to towns in Loudoun County.
Parts of the region receive their water directly from the water utilities
that treat the water. Others receive their water from a water distributor,
i.e., the District of Columbia Water and Sewer Authority, the City of Falls
Church, Arlington County, the Loudoun County Sanitation Authority, the Prince
William County Service Authority, the Virginia American Water Company, the
Town of Herndon, and the Town of Vienna. The water distributors may receive
their water from more than one water utility that is responsible for water
treatment.
To contact the agency that provides your water, or if you do not know or are
unsure of which agency provides your water, please see the water
utility distribution map or go to the table
of utility and health agency contacts by jurisdiction.
- How is my drinking water treated?
Your public drinking water is generally treated in the following way: Dirt
and suspended particles are removed through a chemical process called coagulation.
Then heavy particles are settled out of the water. The remaining water is
passed through filters (sand, gravel, charcoal) to remove smaller particles.
The final treatment step is disinfection with chlorine, chloramines or other
disinfection method. Once purified, the water is either stored or pumped to
the customer through a pipe distribution system.
This flowchart above shows the path that water takes from the intake of the
water treatment plant (from the raw source water) to the storage tank, from
which it is pumped to homes, businesses, and industries. The specific steps
and their sequence may vary somewhat from one treatment plant to another.
Many systems add additional chemicals (e.g., lime, orthophosphate) to minimize
corrosion of pipes and thus reduce the amount of lead leaching into the water.
For specific information on your water provider, please see the water
utility distribution map or go to the table
of utility and health agency contacts by jurisdiction.
- How was the development of the RECPSM funded?
The Washington Regional Association of Grant Makers (WRAG) awarded COG a $75,000
grant to begin the planning process. Later, COG received a $5 million appropriation
from the federal government to address regional emergency preparedness, including
communications, vulnerability threat assessment, regional training and community
outreach.
B. General Facts about Lead
- What is lead?
Lead is a naturally occurring bluish-gray metal found in small amounts in
the earth’s crust. It has no characteristic taste or smell. Metallic
lead does not dissolve in water and does not burn. It can combine with other
chemicals to form lead compounds or lead salts. Some lead salts can dissolve
in water. It is known to be harmful to humans if inhaled or ingested. Because
of the use of lead in manmade products, including past use as a gasoline
additive, it has become widespread in the environment. Lead can be found
in the air, in the water, and on land.
- What are the uses of lead?
Lead has many uses. Lead is found in some types of batteries and is used
in the production of ammunition, sheet lead, solder, some brass and bronze
products, pipes, paints, medical equipment, and some ceramic glazes. Lead
was also found in the chemicals added to gasoline to increase octane ratings,
but its use was banned in 1996.
- What happens to lead when it enters the environment?
When released to land, lead binds with the soils and does not migrate to
ground water. In surface waters it binds to sediments. It does not accumulate
in fish, but does accumulate in some shellfish, such as mussels.
C. Lead and Health Issues
- What are the primary sources of lead exposure in humans?
Nationally, the primary source of lead exposure is lead paint. The
two primary lead exposure routes for humans are inhalation and ingestion.
Lead from airborne sources has been reduced since the phase out
and elimination of lead additives in gasoline. Lead is also found
in urban areas with older homes containing leaded paint which is
also a source of soil contamination. Once lead enters the soil it
adheres to the soil particles. Soil containing lead may also be
blown by the wind, exposing people to lead containing dust. Movement
of lead into groundwater is unlikely unless the water is acidic;
a common situation in acid mine drainage areas. Sources of lead
in surface water or sediment include deposits of lead-containing
dust from the atmosphere, waste water from industries that handle
lead (iron and steel and lead producers), urban runoff, and mining
piles.
Foods such as fruits, vegetables, meats, grains, seafood, soft drinks,
and wine may contain lead. Cigarette smoke also contains small amounts
of lead. Lead gets into food from water during cooking and into
foods and beverages from dust that contains lead falling onto food
during processing. The amount of lead found in canned food (lead
solder joints) decreased 87% between 1980 and 1988.
Levels of lead may build up in plants and animals in areas where
air, water, or soil are contaminated. If animals eat contaminated
plants or animals, most of the lead they eat will pass through their
bodies.
In general, very little lead is found in the groundwater or surface
waters sources of drinking water (lakes, rivers, streams). Groundwater
that is acidic may cause lead found in pipes, leaded solder, and
brass faucets to enter water. Public water systems are required
to treat water to make it less corrosive; this may include decreasing
the acidity of the water.
- What are the health impacts from lead?
Lead can cause a variety of adverse health effects when people are
exposed to it at levels above the U.S. EPA drinking water Action
Level of 15 parts per billion for relatively short periods of time.
Short term health effects may include interference with red blood
cell chemistry, delays in normal physical and mental development
in babies and young children, slight deficits in attention span,
hearing, and learning abilities of children. Long-term exposure
to lead levels above the U.S. EPA drinking water Action Level may
cause stroke, kidney failure, and cancer. See questions C3 and C5
for additional information.
- What is the relationship between the EPA Action Level
for water and lead levels in blood?
This is not easily answered and not fully understood. First of all,
the EPA Action Level for lead of 15 parts per billion (ppb) in water
was established based on reasonable risk assessments. It is the
level that, when reached, EPA requires additional corrective and
educational actions. It does not necessarily directly correlate
to blood lead levels, because lead levels in water may be only one
of a number of contributors to lead to humans. As for blood lead
levels, they are reflective of a variety of factors, i.e., age,
pregnancy, nursing, diet, other lead exposure (dusts, paint chips,
soil), and the amount of water consumed daily. In addition, there
are health studies that demonstrate that various health effects
may be correlated to blood lead levels.
- How much lead is harmful?
Blood lead levels of 10 micrograms of lead per deciliter
of blood (mcg/dL) or greater are considered harmful. This level
has been associated with decreased intelligence, behavior problems,
reduced physical stature and growth, and impaired hearing. A child
is estimated to lose 2 IQ points for each 10-mcg/dL increase lead
in blood lead concentrations. A variety of intervention actions
are taken at various thresholds above 10 mcg/dL.
Pregnant women and women who are nursing are also at risk from lead
exposure. Fetuses have been shown to receive lead from their mothers
and nursing mothers can pass lead through their breast milk. In
both cases, the unborn and young children are taking in levels of
lead that have more of an impact due to their smaller size.
It should be noted that local and state health departments recommend
that children be routinely screened for lead at 9 months and again
at 24 months.
- Does a high level of lead in tap water cause health effects?
High levels of lead in tap water can cause adverse health effects
because the lead may enter the bloodstream and cause an elevated
blood lead level.
Most studies show that exposure to lead-contaminated water alone
would not be likely to elevate blood lead levels in most adults,
even with exposure to water with lead content close to the EPA “Action
Level” of 15 ppb. Risk will vary depending upon the individual,
the circumstances, and the amount of water consumed. For example,
infants who drink formula prepared with lead contaminated water
are considered to be at higher risk because of the large volume
of water they consume relative to their body size.
- Are some people more at risk than others from lead in
drinking water?
Yes. Children under the age of 6, pregnant women, and nursing mothers
are considered to be most at risk. Children because of their smaller
body size and pregnant and breast feeding mothers because of leads
ability to pass through the placenta and through breast milk to
the child. If you fall into one of these categories and are concerned,
contact your local health department or physician.
- What can I do to minimize my exposure to lead contaminated
water?
| If you have lead service lines: |
| • |
The best option is to work with your water supplier,
and/or licensed plumber to replace any service lines and plumbing
containing lead. |
| • |
Other effective option include: |
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- Run your cold water flushing the system for 10 minutes
(see also Section E: Water Conservation). After flushing
for ten minutes, flush the kitchen tap for 60 seconds
before using the water for drinking or cooking. (boiling
water will not remove lead)
- As part of recommended pipe flushing and to minimize
wasted water bathe, use the bathroom, run your dishwasher
or washing machine.
- Use only cold water or bottled water for cooking and
drinking. Heated water tends to concentrate more lead.
- Once your lines are flushed, fill some clean containers
with water and refrigerate for drinking water later on.
- Periodically, remove and clean the strainer/aerator
device on your faucet to remove debris.
- Install and use NSF certified water filters (see C8
below).
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| If your house does not have lead service
lines and was built prior to 1986: |
| • |
Let your cold water run from the faucet for
60 to 90 seconds prior to drinking or cooking, if the water
in your faucet has not been used for more than 6 hours. Leaded
solder may have been used prior to 1986. |
| • |
Periodically, remove and clean the strainer/aerator device
on your faucet to remove debris |
| General guidance for minimizing exposure
to lead: |
| • |
Avoid paints and pigments used in make-up, or
hair coloring that contains lead. |
| • |
Wash children’s hands and faces often to remove potential
lead dusts and soil, and regularly clean the house of dust
and tracked-in soil. |
| • |
Avoid exposure to sources of lead. |
| • |
Do not allow children to chew or mouth painted surfaces
that may have been painted with lead-based paint (homes built
before 1978). |
| • |
For specific guidance related to drinking water, contact
your water utility. View a map
of water utilities. |
| • |
For additional ways to reduce exposure to lead visit the
EPA
lead Web site. |
- Do lead water filters work to remove lead, and where can
I get one?
Yes. There are a variety of water filters on the market certified
to remove lead. They come in a variety of shapes, sizes, and technologies.
They range from units that filter all the water entering the house
to units that attach to the faucet, to units that water drips through
into a pitcher. These filters in general remove about 98% of the
lead. When purchasing a filter, look for filters certified to remove
lead by the National Sanitation Federation International. Finally,
be sure to maintain the filter as instructed by the manufacturer.
You might also check with your water provider to find out if they
have a list of recommended brands. Go to NSF
International for additional information.
EPA Region III has recently suggested that residents, who have been
advised to filter water, filter water after the appropriate flushing
procedures have been performed. Flushing is to ensure that lead
levels entering the filtration devices are within the range that
can be removed by most commercially-available filters.
- Can I bathe, wash clothes, or wash dishes with water that
has lead?
Yes. Bathing and showering, and washing dishes or clothes should
be safe for you and your children, even if the water contains lead
over the EPA Action Level. Human skin DOES NOT absorb lead from
the water. The primary route of lead exposure is through ingestion.
- Is lead contaminated water safe for my pet?
Changes in pet behavior as a result of drinking lead contaminated
water are not likely be noticeable. In general, pets are more likely
to obtain lead as a result of eating an object containing much higher
lead levels (lead paint chips). To be safe check with your veterinarian
and/or give your pet filtered or bottled water if elevated levels
of lead are found in your drinking water.
- How does lead get into my drinking water?
Although sometimes found in natural deposits near drinking water
sources, lead contamination generally occurs from the corrosion
of lead pipes either between the water main and a customer’s
home (lead service lines) or in a home or building’s plumbing
system. Even in homes not served by a lead service line, corrosive
water may cause lead to leach from lead pipes, lead solder, and
brass fixtures.
- What is my water provider doing to reduce the likelihood
of lead in my drinking water?
All water utilities are regulated under U.S. EPA drinking water
regulations, including requirements that help limit lead in drinking
water. Actions taken by utilities to reduce lead exposure may include
replacement of lead water service lines, water treatment to control
corrosion, as well as regular testing and monitoring to ensure compliance
with EPA drinking water regulations.
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What is orthophosphate and why is it being added to my drinking
water? Orthophosphate is a food-grade chemical and is generally
recognized as safe by the Food and Drug Administration. It is
certified for use in drinking water treatment by the National
Sanitation Foundation, and is used widely as a food acidifier
in soft drinks.
Orthophosphate, is a commonly used as a "corrosion inhibitor,"
which when added to finished drinking water will form a protective
coating on the inside of service lines and household plumbing
reducing lead leaching into drinking water. Starting August 23,
2004, it is being added to the drinking water supplies in DC,
Arlington, Falls Church, Vienna, and in parts of northeast Fairfax
County served by Falls Church.
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How long will it take to see reduced lead levels once the
orthophosphate has been added?
According to EPA, there should be noticeable results within
a year in areas with lead drinking water problems, although it
could take longer before lead levels below the federal safety
action level are achieved.
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The addition of orthophosphate may cause drinking water to
temporarily turn reddish-orange (red water). What causes this
color change and what should I do?
The addition of orthophosphate in drinking water may cause
iron to dissolve from water pipes into the water. The color change
is temporary and will normally go away by running your cold water
until it is clear. Do not drink, cook, wash clothes or use hot
water that is discolored. If after repeated flushing the problem
persists, then contact your water utility.
-
4. Will the addition of orthophosphate impact sewage plants
or pollute the Chesapeake Bay?
According to EPA no it will not.
- If I have a groundwater well for drinking water, do I
have to worry about lead contamination?
Drinking water from wells using submersible pumps made of brass
or copper may contain lead at levels that could pose risks to human
health. If the submersible pump is made of plastic or stainless
steel components, lead from the pump should not be a concern. If
you have an individual household well, you will need to test the
water yourself; if you are concerned see question D8 for information
on water testing labs.
- How can I tell if there are lead pipes, lead solder, or
other lead components in my household plumbing?
The existence of lead service lines is often difficult to determine
unless the lines are dug up and examined or unless there are records
available. The first thing to do is to check with your water provider.
They should be able to tell you if you have lead service lines to
your house. Homes that are more likely to have lead lines are generally
those built either in the early 1900’s, during the 1930’s,
or during World War II when there was a copper shortage, and lead
service lines were used. Inside the home, the use of lead service
lines and lead solder is not generally known by the water provider
and would be up to the homeowner to investigate. Brass fixtures,
fittings and valves can contain up to 8% lead. Even new brass fittings
can leach a considerable amount of lead in contact with corrosive
water. The use of lead solder for plumbing was banned in 1985.
- What does the EPA Action Level for lead in drinking water
mean?
EPA has established an Action Level for lead in drinking water of
15 ppb. The Action Level was not designed to measure health risks
from water represented by individual samples. Rather, it is a statistical
trigger value that if exceeded, may require additional types of
treatment, public education, and possibly lead service line replacement.
- How much is a part per billion?
A part per billion (ppb) is a measure of concentration, the amount
of one material contained in a larger amount of another material.
To look at it differently, a pinch of salt in ten tons of potato
chips or one drop of an impurity in 500 barrels (about 26,500 gallons)
of water would represent a part per billion.
- How do I know if I should be concerned about lead in my
drinking water?
The only way to know whether your tap water contains lead is to
have it tested. Lead can normally not be seen, tasted, or smelled
in drinking water. First, check with your water provider to find
out what testing has been done in your area. For homes served by
public water systems, information on lead in tap water may be available
on the internet from your local water provider. If not call your
water provider to find out. For more information on how to test
your water system see question D8.
- How can I get my water tested?
If you are concerned about the possibility of lead in your drinking
water, first contact your water provider. Unless there is a recognized
lead problem, most water providers will not offer testing for individual
homes or businesses. Nevertheless, they may be able to provide you
with a contact list of private laboratories certified to perform
a lead water test.
- Are there limits on how much lead can be in drinking water?
Yes. The U.S. EPA has set an Action Level for lead at 15 ppb. Given
present technology and resources, this is the level to which water
systems can reasonably be required to control this contaminant should
it occur in drinking water in homes. Fewer than 1 in 10 homes sampled
are allowed to exceed this Action Level. If the Action Level is
exceeded in 10 % or more of the homes tested, then additional corrective
actions are required under federal regulation.
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What do you recommend I do if I want to conserve
water and follow the guidance to flush my water lines?
There are a number of simple steps you can take to conserve water
and also follow the recommendation to flush your water line prior
to use. In the morning take a shower or run your washing machine
or dishwasher and flush your tap for 60 seconds prior to drinking
any tap water. When you run water from the faucet, fill up jugs
or other containers with water and use it later to water your
garden or household plants. Once your lines are flushed, you should
fill up several clean jugs of water and place them in the refrigerator
for drinking. For more information on using water wisely visit
the campaign Web
site.
Wise
Water Use Tips: A guide for those with lead service lines
Wise
Water Use Tips: A guide for those without lead service lines
(concerned about lead in water and/or live in a house built prior
to 1986)
Click
here for a PDF verison of these wise water use tips
F. For Further Information
Water Utilities Map or System
Description
Jurisdictional table of water utility and health
agency contact information
Health
Departments (local, state, federal)
EPA Drinking Water Hotline 800-426-4791
Community Right to Know
800-535-0202 or l or EPA Region
III
CDC
MWCOG
American Nurses Association
District
of Columbia
Arlington County
City of Falls Church
USGS
The Maryland Department of the Environment;
(410) 537-3000, or toll free in Maryland (800) 633-3101
The Virginia Department of Environmental
Quality; (804) 698-4000, or toll-free in Virginia 1-800-592-5482
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