What is chromium?
· Chromium
is a benign element found in nature. It
is commonly used in manufacturing activities such as steel hardening, aerospace
manufacturing, making of paint pigments, and electroplating. When chromium is used in industrial
processes, it’s often converted to chromium VI.
·
Chromium may be present in water as chromium III and
chromium VI. Chromium III is an
essential nutrient at trace concentrations.
Chromium VI can be present in many forms, some of which are carcinogenic
when inhaled at high concentrations. At
this time, tests do not identify the form of chromium VI that may be present in
drinking water. Scientific studies
performed to date have not shown evidence of illness associated with drinking
water which contains chromium VI.
·
Current regulatory standards assure safe levels of total
chromium—the combination of chromium III and chromium VI—in drinking water to
protect against any possible inhalation hazard. In fact, as an added measure of safety, the state has established
a very stringent health protective
level for chromium in drinking water even before all of the necessary health
studies have been completed to set a formal regulation.
Why the recent interest in chromium VI?
·
A recent movie has focused massive public attention on the
potential dangers of chromium VI. The
movie was based on events that took place in the town of Hinkley, California,
where an extraordinarily high concentration of chromium VI was found in the
drinking water. However, there is a lack of factual evidence to
substantiate the claim that a multitude of illnesses in the town were linked to
chromium VI.
·
There is an unfortunate perception that this is a new
problem. In fact, chromium health
effects have been studied for years with a focus on the inhalation of airborne
chromium VI particles—the primary source of risk. The first health effects study on chromium dates back to 1948,
and studies continue through to the present day.
Is my drinking water safe?
·
Yes. Calleguas water
meets all state and federal standards, maximum contaminant levels, public
health goals, and health protective levels for total chromium and chromium
VI.
·
Calleguas’ source is surface water from the State Water
Project, which contains concentrations of chromium VI which are barely
measurable with the latest laboratory technology. None of Calleguas’ water supply comes from groundwater basins,
which are the sources most vulnerable to chromium VI contamination through
industrial pollution.
·
Metropolitan and Calleguas conducted special sampling for chromium VI. Average levels of chromium VI detected are
0.08 parts per billion (ppb), and ranged from 0.03 to 0.11 ppb. These samples were analyzed with a reporting
limit of 0.01 ppb. These concentrations
are considered safe according to state and federal drinking water standards.
·
Based on the California Department of Health Services’
recommended reporting level of 1 ppb, chromium VI would have been reported as
“None Detected” for all Calleguas and Metropolitan samples.
·
Calleguas also monitors its sources annually for total
chromium with no detections.
·
Chromium occurrence is regulated through a federal maximum
contaminant level of 100 ppb, a state maximum contaminant level of 50 ppb, a
state public health goal for total chromium of 2.5 ppb, and a state “health
protective level” of 0.2 ppb for chromium VI.
·
Calleguas concerns itself first and foremost with the
protection of public health. We support
state and federal regulators in their efforts to set water quality standards for
drinking water based on good science with consideration for available
technology and costs. For those
interested in more information, a reference database of
reports on chromium may be found at www.calleguas.com.