The Basics about Lead in Drinking Water
What you need to know
- Lead is a heavy metal that can enter drinking water.
- Lead exposure is a public health risk, especially for pregnant women and children under age six.
- Lead in drinking water can affect each home in the District differently. Drinking water is essentially
lead-free in the distribution system and prior to entering your individual water service pipes.
- Lead can enter water that travels through a lead service pipe, lead solder or household plumbing containing lead.
- Lead exposure can be minimized and involves the shared responsibility of DC Water and individual residents.
Lead exposure and health
Lead can cause serious health problems if too much enters your body from drinking water or other sources. The greatest
risk of lead exposure is to infants, young children, and pregnant women. Lead can cause damage to the brain and kidneys,
and can interfere with the production of red blood cells that carry oxygen to all parts of your body.
Scientists have linked the effects of lead on the brain with lowered IQ in children. Adults with kidney problems
and high blood pressure can be affected by low levels of lead, more than healthy adults. Lead is stored in the bones,
and it can be released later in life. During pregnancy, the child receives lead from the mother's bones, which may
affect brain development.
Sources of lead in drinking water*
- A lead service pipe
- The pipe that connects the water main in the street to your household
plumbing. A portion of this pipe is in public space (DC Water's responsibility)
and a portion is on private property (property owner's responsibility).
A "partial" lead service pipe replacement is where a portion of the pipe
is replaced, but a portion made of lead remains in public or private space.
Lead service pipes were installed until the mid-1950s.
- Lead solder
- Connects pipes in household plumbing. In 1987, lead solder was banned from use
in household plumbing. If your household was built before 1987, your plumbing
may have lead solder.
- Brass faucets, valves or fittings
- Almost all faucets, valves and fittings have brass components. Until 2014, brass
faucets and fittings sold in the United States that are labeled "lead-free"
can contain up to eight percent lead.
- Galvanized iron pipes
- Household galvanized pipes are old, corroded pipes that were installed in many
homes before the 1960s. These pipes can release lead in water if you have, or
once had, a lead service pipe. Galvanized pipes are made with a protective
layer of zinc. However, overtime, the zinc layer erodes and results in corrosion.
When lead is released from a lead service pipe and passes through galvanized
plumbing (particularly over decades of use), lead can accumulate on the inside,
corroded walls of this plumbing.
- Lead release from galvanized pipes can vary from home to home and can continue
to occur even after a lead service pipe is replaced. Galvanized pipes can cause
other water quality problems, such as low water pressure and discolored water.
For additional information on household plumbing
click here.
- * To minimize lead release in water, the Washington Aqueduct adds a food-grade chemical,
known as orthophosphate during the water treatment process. Orthophosphate creates a thin
protective coating inside pipes and plumbing fixtures in the distribution system and individual
households. It is very effective in reducing the presence of lead and other metals in household
water. However, it is less effective on corroded galvanized pipe.
How to identify lead sources
- Test your water for lead:
- DC Water offers free lead testing for customers. We will deliver a lead test kit to your
household and provide follow-up guidance based on your test results. Contact Customer
Service at (202) 354-3600.
- Learn about your pipes and plumbing:
- A lead service pipe: Contact Customer Service at (202) 354-3600 to request information
about your water service pipe. DC Water maintains records of water service pipes in public space.
Please note that this historical data may be incomplete and does not include information about
the service pipe material on private property.
Homeowners are responsible for the water service pipe and household plumbing on private property.
To determine the material of the service pipe material on your private property, check your
household water service connection, typically located in the basement. Lead is a gray metal
and easily scratched with a coin. You can also contact a licensed plumber to determine your
service pipe material.
- Household plumbing:Use our household plumbing guide or contact a licensed plumber to
inspect your pipes. Check out DC Water's guide to household plumbing
here.
- Brass faucets, valves or fittings: Check with the manufacturer of your fixtures about the
percentage of lead in your plumbing. Install fixtures and fittings that contain 0.25 percent
lead or less.
How to minimize lead exposure
- Remove lead sources
- Replace a lead service pipe with copper. DC Water will replace your lead service pipe in public
space if you choose to replace the private portion. To find out more about lead service pipe
replacements, contact Customer Service at (202) 354-3600.
- Replace household galvanized plumbing.
- Install lead-free plumbing fixtures. It is important to know that fixtures may be labeled
"lead-free" and still contain up to eight percent lead. Make sure you install fixtures and fittings
that are at or below 0.25% lead.
- Flush cold water taps after installing new household pipes or fixtures. New plumbing can release
metals after installation. Flush for five minutes at a high flow rate once a day for three days.
- Use filtered tap water
- Be sure to select a filter certified to meet NSF Standard 53 for lead removal. The filter package
should specifically list the device as certified for removing the contaminant
"lead."
- We recommend devices that are installed at your faucet tap (also known as point-of-use) or
pitcher-style filters.
- If you are pregnant or have children under age six, use cold, filtered tap water for drinking
and cooking until all sources of lead are removed.
- Use cold, filtered tap water for preparing infant formula, beverages and ice.
- Be sure to routinely replace filter cartridges according to the manufacturer's instructions.
- DC Water Filter Guide - A guide to selecting and using a drinking water filter.
- Do not use your hot water tap for drinking and cooking
- Always use cold tap water, then heat water if necessary.
- Hot tap water can cause a greater amount of lead to release from plumbing. Always use cold tap water,
including water used for making ice, beverages and infant formula.
- Run the cold water tap when water is not used for several hours
- Run your cold water tap for two minutes before using it for drinking or cooking.
- Lead and other metals can dissolve in water when it sits in pipes for a few hours.
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