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Lead piping was popular in plumbing
systems until the early 1900’s. There is little danger of
encountering excessive levels of lead in the pipes of a
house constructed using modern materials and methods but
lead in drinking water can be a problem in houses that are
very old or very new.
Sources
The most common source of lead in the water delivery
system of old homes is the piping, but even in newer homes,
piping is not the only area from which lead can enter a
plumbing system. Common sources of lead in the water
include:
Made entirely of lead, highly corrodible and
susceptible to the chemicals found in tap water
Contain small amounts of lead used in their
casting, can be corroded by water. Both "hard" and
"soft" water can contain chemicals that can be slightly
corrosive after long exposure, have an excessively low
or high pH, or contain corrosive minerals
Often joined with lead-based solder
Brass or bronze pumps that can leach lead
Well screens with a "lead packing collar"
Wells that were packed with lead shot or lead wool
to keep out sand
Some public service connections installed before
1930 used lead piping
If your home was built before 1930, it is likely to
contain lead piping. If it was built before 1988, it is
likely to contain copper piping joined by lead-based solder.
In homes with pipes that are joined using lead solder, it
is likely that water run through the pipes after a long
period of non-use (such as first thing in the morning) will
pose the greatest threat of lead contamination.
Health Effects
Lead in the human body can be toxic and cause serious
damage to many areas of the body including:
- The brain
- Kidneys
- The nervous system
- Red blood cells
Children are more susceptible to damage caused from a
buildup of lead in the body. They can suffer such serious
health effects as:
- Damage to the nervous system
- Behavior and learning problems
- Slowed growth
- Hearing problems
Problems can also occur in adults:
- Ill effects during pregnancy
- Reproductive problems
- High blood pressure
- Digestive difficulties
- Nerve disorders
- Memory and concentration problems
- Muscle and joint pain
Testing
Lead cannot be seen, tasted, or smelled if it is
dissolved in water, but if you suspect that your water
supply may be contaminated by lead, or if you are not sure
about the condition of your water, it should be tested to
make sure that lead levels are within a safe range. Home
test kits are available but may not provide accurate results
regarding lead levels in your water. For a completely
accurate evaluation of your water supply, a certified
laboratory should perform the testing. This usually
costs between $20 and $100. Some laboratories will send a
trained and certified technician to make sure that water
samples are correctly collected, but most will not. In this
case you will be asked to collect tap-water samples
yourself. It is important that you follow the procedures
specified by the laboratory so that your water quality can
be accurately determined. The most common procedure for
taking water samples is to obtain a "first draw" sample and
a "fully flushed" sample:
First draw - A sample collected after the water
has sat motionless in your system for six or more hours.
No water must be allowed to run before the sample is
collected or the sample will not be accurate.
Fully flushed (purged-line) – A sample collected
after the water has run through the tap for at least five
minutes.
The laboratory will compare these two samples. If the
lead content of the first draw sample is higher than that of
the fully flushed sample, then the water is leaching from
the in-house plumbing system. If both water samples contain
the same amount of lead, then the contaminated water most
likely originates from a source outside the household
plumbing system.
Control/Remediation
Temporary Measures
If the water in your plumbing system is contaminated with
harmful levels of lead, there are several steps that can be
taken to control or remove the hazard. The first and most
important step to take is that of attempting to determine
the source of the lead contamination and remove it
completely. In many cases, steps can be taken to
eliminate enough of the lead in water to make it potable
until measures can be taken to permanently remove the source
of lead.
Water from a system having lead piping should not
be consumed under any circumstances, as the possibility of
severe corrosion in old, all-lead pipes is too great to
bring to completely safe levels. The only way to
completely remove the hazard of lead contamination in the
water of homes having lead piping is to remove and
completely replace all of the lead pipes in the system.
- Lead solder, copper fixtures, wells
The water in systems having these types of potential
hazards can be "flushed" to safer lead content levels in
many cases, until the proper measures can be taken to
completely remove the source of the hazard.
Do not consume water that has been standing in the
pipes for more than six hours
"Flush" water sources before use until the water is
as cold as it is likely to get (this must be done for
each drinking water faucet or tap before use)
If the lead contamination originates from a lead
service connector, flush for at least an extra 15
seconds after the water is running cold
Never consume or cook with hot water as it is
more likely to contain higher levels of lead
NOTE: These methods are only temporary measures of
reducing the risk of lead poisoning. They should only be
employed as long as it takes for the source of lead to be
removed and replaced.
Treatment
In lieu of replacing the hazardous parts of a plumbing
system, there are several methods of treating water to make
it less corrosive, or to remove lead from water.
Water treatment
Several devices are available to treat water to make
it less corrosive, including:
- Calcite filters
- Carbon cartridge filters
- Ion exchange resin cartridge filters
- Activated alumina cartridge filters
-
Lead removal
Lead removal devices are typically applied
individually to faucets and are not 100% effective,
but can usually remove at least 85% of lead from a
water system. They may employ such methods as:
-
Reverse osmosis
-
Distillation
-
Carbon filters
These procedures may not be appropriate for your plumbing
system; you should consult a professional to make sure these
measures are sufficient to reduce the lead content to
acceptable levels before implementing them.
Exposure Guidelines
In accordance with the Safe Drinking Water Act, the EPA
sets the minimum acceptable level for lead at under 15 parts
per billion (1 part per billion = 1.0 microgram per liter or
.001 milligram per liter). Utilities are required to
maintain standards meeting this regulation. You should be
concerned about water lead levels if your water supply tests
at or around 15 ppb (parts per billion).
To find a qualified lead testing company
in your area, look under "Laboratories" in your local yellow
pages, or contact your state or local health or
environmental department.
For more information about lead, call:
EPA Safe Drinking Water Hotline:
1-800-426-4791
National Lead Information Center:
1-800-LEAD-FYI
On the web:
http://www.epa.gov/safewater/drinklink.html
http://www.epa.gov/lead/nlic.htm
www.hud.gov/offices/lead
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