Survey: Pittsburgh Water High in Chromium-6
Pittsburgh Tribune-Review
27 December 2010
By Matt Neistein
A study released by a nonprofit public health group found only eight
cities in America have higher levels of a potentially deadly chemical
compound in drinking water than Pittsburgh, but local experts say
residents shouldn't panic.
Hexavalent chromium, known as chromium-6, can leach into water sources
from natural deposits and is contained in discharges from steel and
pulp mills. The Environmental Protection Agency, which does not have a
standard allowance specifically for chromium-6, is reviewing its policy
on the compound.
A draft of that policy says hexavalent chromium is "likely to be
carcinogenic to humans" when ingested orally.
The Environmental Working Group tested drinking water in 35 cities and
detected chromium-6 in 31 of them, according to the report released
last week. In Pittsburgh, the measurement was 0.88 parts per billion
(ppb). The worst finding was in Norman, Okla., at 12.9 ppb.
However, Leonard Casson, associate professor of environmental
engineering at the University of Pittsburgh, said it is unlikely that
local faucets pose an imminent threat.
"If the EPA felt that there was an urgent need to change that maximum
contaminant level, if there was an existing health problem that they
knew about, they would do that," he said. "Our public drinking water is
more highly regulated than some small bottled-water producers."
Chromium-6 was at the center of the movie "Erin Brockovich," about a
woman who helped build a lawsuit against a power company whose
indiscriminate use of the compound tainted groundwater in Hinkley,
Calif. That state since suggested enforcing a standard of 0.06 ppb for
chromium-6 levels in drinking water.
The EPA requires water treatment plants to test for total chromium, of
which chromium-6 is a part, and keep levels below 100 ppb.
Stanley States, the Pittsburgh Water and Sewer Authority's director of
water quality and production, said the authority typically finds 1 to 2
ppb of total chromium in its samples.
"Realistically, that's at the limit of the ability to detect it
analytically," he said. "We have no problem at all with any of the
heavy metals in the river. What makes (chromium-6) a newer issue now is
there's some more recent data that indicates ingestion may be a
problem."
States said the EPA asked the water authority — and similar agencies
nationwide — to monitor water for chromium-6 as part of the ongoing
review. That information will be used if and when the EPA develops a
policy for the compound, which States expects to occur in about a year.
The federal agency could make its total chromium standard more
stringent without specifically creating one for chromium-6, he said.
Casson notes that several factors would be considered in that decision,
including cost and detection levels.
For example, the Pittsburgh Water and Sewer Authority doesn't have
available methods to test for chromium-6 down to the levels the
Environmental Working Group report found, States said. And if the EPA
creates a standard as low as California's suggestion, it would have
wide-ranging impact.
"To remove something like this, if it's at really low concentrations,
could really result in significant change in treatment," he said.
That "significant change" likely would require millions of dollars of
equipment and training, the cost of which almost certainly would be
passed along to customers.
"You have to realize that PWSA, in their treatment plant, is doing 100
million gallons of water," Casson said.
States said if water customers are worried about the level of
chromium-6 — or any harmful trace elements — in drinking water, using a
reverse-osmosis filtration device in the home removes them. The
starting price for such systems typically is about $200.
Matt Neistein can be reached at mneistein@tribweb.com or 412-380-5683.