Talkin’ UCMR3 Blues…
Risk, Regulatory “Risk” and Public Health
By Bruce A. Macler
So you’ve been collecting samples for
your federal Unregulated Contaminant
Monitoring Rule 3 requirements.
The results are starting to come in.
You didn’t find any of the estrogens or androgens,
no perfluoro compounds, no pesticides,
no 1,2,3-trichloropropane. You did
get a detection for 1,4-dioxane. But, that
was it for the organics. Not too bad.
The inorganics were quite different,
however. Every sample had strontium and
hexavalent chromium. More than half had
chlorate, vanadium, and molybdenum. The
levels were low; none reached the Health
Reference Levels USEPA provided. But they
are in your drinking water. Are your customers
One of my colleagues at USEPA remarked
about the UCMR3 data that, “It is
heartening that we can now detect materials
in drinking water at levels well below
their harmfulness.” It’s certainly true that
detection limits are continually getting
lower and lower. However, there are other
people who would say, “You found hexavalent
chromium, a known carcinogen, in our
water. You’re poisoning us!” What you find
from Internet searches are answers just as
diverse, if you can understand the technical
jargon at all. You may be getting calls already
from the media and the public. What
do you tell them?
One of the CA-NV AWWA’s goals is to
inform the public about the water it drinks.
Here are some thoughts on what you
26 SOURCE summer 2014
could say—and maybe not say—regarding
detection of these materials.
1) First off, I’m assuming that you are actually
concerned, as you should be. You,
and probably your family, drink the
water, too. It’s an honest and appropriate
thing to note that it’s a utility’s job
to provide safe and reliable water to its
customers. That’s part of its service to
the public. Almost all utilities do a very
good job, comply with all standards, and
work to meet their customers’ needs
and desires. If and when the regulatory
agencies advise or direct you to do more,
you will endeavor to do so.
2) Second, your utility isn’t a public health
agency. While understanding the general
health and risk implications of what’s
in your water is appropriate, there are
others better suited to discussing this in
detail. Don’t assume the public will trust
what you or others in your organization
might opine about the safety of your
water. Why should they? You are
probably not a public health officer or
medical doctor. It’s best to leave the
judgment call on safety to the public
health community. Say what you know
and refer to others when you don’t.
The U.S. Centers for Disease Control
and Prevention have information on its
website that can be helpful: www.cdc.
useful are the Public Health Statements
on the Agency for Toxic Substances and
Disease Registry website: www.atsdr.
Public Health Statements are in plain
English and provide useful information.
But, while these should be helpful,
your customers may still be skeptical.
Establishing a relationship with your
County’s Health Officer, discussing
these issues and arranging for their
participation in your communication
efforts would be worth your effort.
3) WWhile USEPA and the California Office
of Environmental Health Hazard
Assessment (OEHHA) are not public
health agencies, they do regulatory risk
assessments to help guide development
of drinking water standards. By convention
or statute, these assessments are
designed to be conservative with respect
to data quality, human exposures
and individual variations in sensitivity.
In general, they try to estimate exposure
levels to contaminants that would
pose a very low (de minimus = without
consequence) risk to the more-sensitive
members of the public. These risk
goals are most often far lower than the
risks associated with available toxicological
and epidemiological data for a
given contaminant. A variety of policies,
assumptions, models and statismanager’s