Hexavalent Chromium (Cr6)

May 2016--CMUA
Hexavalent Chromium (Cr6)
in Drinking Water
Implications of New MCL of 10ppb in California
Chromium in
California
Drinking Water
1/3 of drinking water sources in
the state have Cr6 at or above 1
ppb, which in most cases is
naturally occurring.
448 drinking water wells
statewide contain Cr6 levels
exceeding the new 10 ppb Cr6
MCL.
All but 9 of these sources are
below 50 ppb
• The PHG was based on data from a 2008
National Toxicology Program (NTP) 2-year
drinking water ingestion study.
Evaluation of
Cr6 in
Drinking
Water
Science
• The NTP study observed small intestine
tumors in mice only at the highest Cr6 doses
tested (60,000 and 180,000 ppb).
• The new Mode of Action (MOA) research
on Cr6 health effects was not evaluated in the
PHG risk assessment because the new studies
were not completed at the time the PHG was
adopted in 2011.
• The new MOA research, now complete,
investigated potential for adverse health
effects across a broad range of exposure
levels, including levels far lower than those
investigated in the 2008 NTP study—down to
100 ppb.
The MOA
Research
• The MOA findings provide a large
body of new, peer reviewed
scientific evidence showing Cr6
presents a materially lower risk
to public health than determined
in 2011.
• A risk assessment based on the
new MOA research concluded
that a drinking water standard in
the range of 210 ppb, over 20
times the level of the current Cr6
MCL, would be protective even of
sensitive populations such as
infants and children.
Petition to
Reconsider the
PHG
• In 2013, a petition was filed with
OEHHA to re-open the PHG and
examine the new MOA data.
• OEHHA denied the petition in
early 2015, stating that it would
reconsider the available science on
the 5-year anniversary of the PHG
(July 2016), as required by California
drinking water law.
Regulation of
Cr6 in Other
Jurisdictions
• U.S. EPA has acknowledged the
significance of the MOA research and has
committed to reviewing the new studies.
• Health Canada has proposed a
maximum acceptable concentration (MAC)
for total chromium in drinking water of 100
ppb - a revision upward from the 1986 MAC
of 50 ppb.
• The Texas Commission on Environmental
Quality (TECQ) recently published a
reference dose of 100 ppb.
Health Canada
• Both reviews are based on the MOA
research.
Economic
Impacts of New
Cr6 MCL–The
Bottom Line
• Establishing the Cr6 MCL at 10 ppb means
hundreds of California drinking water sources
will need to be taken out of production or
treated.
• Yet the new research indicates these actions
will not yield a public health benefit.
• Recent state-wide annualized cost estimates
to achieve a 10 ppb drinking water level have
been reported at up to $2 billion, far higher than
CDPH’s 2014 estimate of $156 million.
• Given the extent of natural occurrence of Cr6
in California, the financial burdens of MCL
compliance will fall heavily on families and
businesses connected to water systems,
particularly small systems serving low-income
areas.
Increasing
Water RatesNot a Viable
Option
• Even CDPH’s cost estimate, which underrepresents impacts on small water systems, amounts
to an annual cost of compliance of $5,627 per
connection for systems serving less than 200
connections.
• This per connection cost represents 10% of the
statewide median household income, 12% of the
median household income in disadvantaged
communities, and over 16% of the median household
income in severely disadvantaged communities.
• At a more realistic annualized cost of compliance
of $2 billion the impacts on all systems would be far
greater.
• In many service areas, Governor Brown’s
mandatory water conservation orders are already
forcing steep rate increases, so raising drinking water
rates further to cover removal of low level naturally
occurring contaminants is not a sustainable option.
Human Right
to Water
• Guaranteed access to, and
affordability of, drinking water are
new mandates under California’s
Human Right to Water Act that must
be balanced with the need for safe,
clean water.
• This balance can be best achieved by
setting drinking water standards at
safe exposure levels identified by the
best available scientific evidence,
rather than at levels far below what
is necessary to provide public health
benefits.
Competing
Demands on
Limited Drinking
Water Budgets
• Cr6 not an isolated case – arsenic, nitrate,
perchlorate and other new and revised standards
amount to billions of dollars in new liabilities for
water utilities and their ratepayers.
• The alternative to raising water rates is to
forego spending on projects that provide
immediate health benefits to ratepayers:




Alternative water supplies for groundwater
dependent systems in over-drafted areas;
System consolidation to support struggling
disadvantaged communities;
Long overdue infrastructure repair and
replacement to ensure system integrity and
reliability; and
Water conservation projects to gird systems
against current and future drought cycles.
Limited Benefit
from Compliance
Extensions
• New legislation (SB 385, Hueso)
gives drinking water utilities up to
five years to comply with the new
Cr6 standard.
• The legislation simply delays the
inevitable water rate increases,
water utility budget cuts or curtailed
spending on more urgent system
needs.
Revisiting the
Cr6 PHG
• The 5-year anniversary (July
2016) of the 2011 PHG decision is
the right time to reopen the Cr6 PHG
of 0.02 ppb to fully consider the new
body of peer reviewed scientific
evidence that is directly relevant to
humans exposed to low levels of Cr6
in drinking water.
• A revised PHG will support a
more responsible and sustainable
MCL