By Brian Rohrig
Lead in Your Water : Is Any Amount Safe?
The Lead and
In the United States, the U.S.
Agency (EPA), which is the
governing body that oversees the
protection of the environment,
enforces regulations that are
meant to keep water safe. One
of them is the Lead and Copper
Rule (LCR). Although the rule
is relatively simple, what is less
clear is whether it is really effective in protecting consumers.
The LCR states the following:
After testing water taken from the
taps of consumers, if more than
10% of the samples exceed 0.015
milligrams per liter (mg/L) for
lead or 1.3 mg/L for copper, then
further steps must be taken. But
when these levels are exceeded,
a complete shutdown of the water
supply is not required. The ques-
By Adrian Dingle
tion then becomes, is the action
that is mandated when these
levels are exceeded enough?
Is letting the public know about
the problem, requiring additional
water treatment by the supplier,
and advising people about how
to avoid problems sufficient to
keep consumers safe? These are
some of the questions that some
people have been grappling with,
and you may want to consider
them, as well.
What does 0.015
mg/L really mean?
Because 1 L of
water has a mass
of 1,000 g or
1 million milli-
grams, then 1 mg
of a contaminant
in 1 L of water
is equivalent to
1 part per million
(ppm). Because 0.015
mg/L is 1,000 times
smaller than 15 mg/L, then
0.015 mg/L is equal to 15 parts
per billion (ppb). To give you an
idea of how small that amount is,
15 ppb is equivalent to approximately 45 seconds in a whole
The World Health Organization (WHO) says, “There is no
known level of lead exposure
that is considered safe.” In addition, the action level for lead
was never based on any medical research; rather it was what
water suppliers considered to be
a manageable number when the
LCR was issued in 1991.
After testing water taken
from the taps of con-
sumers, if more than
10% of the samples
exceed 0.015 mil-
ligrams per liter
(mg/L) for lead or
1.3 mg/L for copper,
then further steps must
Sometimes, the WHO and EPA recommendations vary (as is the case with lead),
but in other cases, there is more agreement.
For example, in the case of arsenic, 0.010
mg/L ( 10 ppb) is considered an acceptable
level by both organizations.
So what can you do? Ask the company that supplies your
drinking water for its annual water quality report. It will list all kinds
of chemicals that are found in your water supply, along with their concentrations. Then, find out if some of these chemicals exceed the WHO
or EPA recommendations. The number of chemicals that are in drinking
water might surprise you and, hopefully, they will all be below the levels
recommended by WHO or EPA.
The recent lead contamination problem in Flint, Mich., was not he first time there has been a severe public health issue
caused by a tainted water supply. As recently as February
2016, officials in Ithaca, N. Y., distributed bottled water to
children after lead levels that were hundreds of times
higher than recommended were detected in drinking
water in a local school. Similar cases have come to
light in Portland, Ore., Newark, N.J., and in Baltimore, Md.
As in Flint, many of the problems in these other
cases were due to the corrosion of pipes that carried
water to people’s homes, and, as in Flint, among the
main culprits were copper and lead. But the water we
drink everyday already contains small amounts of lead
and copper (along with other metals), so how do we know
when their amounts are too high to make water unsafe to drink?