Lead in Drinking Water, What You Should Know

[Around the Water Cooler interview March 17, 2010,  excerpted and edited for clarity by Jonathan O. Hall.]
Professor Mark Edwards, PhD is the Charles Lunsford Professor of Civil Engineering at Virginia
Tech University. The Journal Environmental Science and Technology has selected a paper
written by Dr. Edwards and his associates as the best science paper of 2009 and this is among
about 1500 papers that they publish annually. Prof. Edwards is the fourth recipient of the
Villanova University’s Praxis Award in Professional Ethics. Mark has won a McArthur Fellow,
and in 2007 was awarded a five-year grant of a half million dollars to expand his research into
safe drinking water. Prof. Edwards was a keynote speaker at the Water Quality Association
Conference in March 2010.
JONATHAN: Welcome to the show, Mark.
MARK: Thank you for having me, Jonathan.
JONATHAN: Mark, the American Society of Civil Engineers, and you’re an engineer, has rated
the drinking water infrastructure in the US as a D-minus. And on this show, just a couple weeks
ago, Professor Edward Bauer, the Abel-Wolman Professor of Environmental Engineering and
Chair of the Department of Geography and Environmental Engineering at John Hopkins, said
that there’s greater uncertainty now than in the past in terms of the safety of our drinking water.
And we’re not trying to promote fear here, but do you agree that the lack of investments and an
infrastructure in this country is compromising efforts to provide high qualify safe drinking
MARK: Well, in general citizens in the US can have great faith in the quality of their tap water.
But it is true that we have failed to invest in our water infrastructure, particularly the pipes that
bring water from the treatment plan to your home. So even if you have the very best water
treatment plant in the world and, you know, you operate at highest efficiency, if that clean water
goes through a series of rusty old pipes full of bacteria and holes, the drinking water that you get
out of your tap can have bacteria, rust, and potential contaminants in it as well. So this is
something that we could and should do more with, in terms of spending money to upgrade this
JONATHAN: Well, you and I both know that one of the biggest challenges here, when you’re
talking about old pipes failing, are leaks. Approximately 15-40 percent of treated water from
plants in the U.S. is leaked prior to reaching customers. How do leaks pose a danger to water
supply and how serious are water main breaks?
MARK: Well, one issue is just the lost resource itself. You know, as we tried to make our water
go further and we try to conserve at home, it makes little sense to just waste 15-to-40 percent of
the water through these leaks in pipes, and this has a big value, too, on the order of $3-5 billion a
But about a decade ago, what we discovered is contrary to your popular wisdom, where a leak in
a water pipe will shoot out into the ground surrounding it, that there are occasionally things
called pressure transients, negative pressure waves, which can essentially suck that water back
into the pipe and so if the pipe is in soil or it’s near a sewer line, potentially during these unusual
hydraulic events, you can suck dirt and contaminants into the water supply and that’s a public
health concern.
JONATHAN: You know, you spoke at the American Public Health Association meeting last fall,
and I was there, but the comment that was not attributed to you, but to someone else, is that
drinking water regulations in the US were developed primarily for relatively clean water, but
during the past couple decades, lots of new compounds have been invented to make life better,
but these are finding their way into drinking water and they’re dangerous to human health and
they’re not regulated. Can you comment?
MARK: Well, this is a very important, emerging concern, that we’re only beginning to get a
handle on. Most of these new contaminants, which include pharmaceuticals, antibiotics,
endocrine disrupters, are present in the water supply at extremely low concentrations, and so we
have to learn a lot more about potential health risks, how we can remove these contaminants
from water and when they occur. And so the water (industry) and the EPA are currently funding a
great deal of research on the subject and as we learn more in the years ahead, you’ll learn more
about the dangers and the cost benefits of trying to address and remove these contaminants.
JONATHAN: Yeah, if I’m reading you correctly, Mark, or hearing you correctly, it’s not
something where the general public has to be scared or afraid right now, but at the same time, the
jury’s still out, is that fair?
MARK: Yes, I mean, we’re always learning more, and again, realize these contaminants are
present at extremely low levels, but nonetheless, there is evidence emerging that they can
sometimes have significant health effects at these low levels, and so we do need to invest in
research, we do need to improve our knowledge about these contaminants.
To listen to the entire Around The Water Cooler broadcast with Prof. Mark Edwards, go to
www.blogtalkradio.com/aroundthewatercooler and select the March 2010 broadcasts.

About Me

Jonathan Hall is a drinking water advocate. He blogs at hallwater.com and has worked as an independent strategy and social media content consultant.