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newsletter summer 2002 |
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Site Visit Story—Sniffing
Out Mercury
helping businesses reduce waste &
maximize efficiency
Story: Burr
Technology Inc., of Little Canada, received a notice of violation
from the Metropolitan Council Environmental Services (MCES)
after submitting its required water test results in January.
Specializing in mechanically polishing and removing burrs
from metal parts, Burr Tech exceeded the legal wastewater
limit of two parts per billion of mercury—a toxin associated
with nervous system disorders. Burr Tech was given 30 days
to reduce wastewater mercury levels before MCES would order
the facility not to discharge to the sewer.
“I hadn’t realized we were in
violation. I was totally surprised by it,” said owner,
Remi DuCharme. “I thought perhaps it was from a job we
were running at the time we were tested.”
No mercury was found after looking at material
safety data sheets and testing deburring chemicals used on
the days yielding high mercury levels. Not knowing where else
to look, DuCharme contacted MnTAP engineer Karl
DeWahl for help.
Karl suggested Burr Tech look at chemicals
containing sodium hydroxide, which can be contaminated with
mercury. But, none of the chemicals tested were a source.
Karl’s mercury research pointed to
mineral abrasives, thermoset plastic liners—made of polyurethane—and
plastic polishing media as possible contaminant sources. Consulting
Ed Swain, Minnesota Pollution Control Agency (MPCA) mercury
expert, confirmed his theory. To zero in on the mercury source
Burr Tech had MPCA use its Lumex, a mercury vapor analyzer,
and Clancy, a mercury detecting dog, to scan the facility.
Results:
The Lumex detected mercury vapors coming from two of Burr
Tech’s 11 tumblers. Clancy was unable to identify the
contamination. Mercury fumes in the tumblers may have dissipated,
or Clancy was not able to get close enough to the tumblers’
elevated doors to identify them as a mercury source.
Burr Tech tested the polyurethane liners
of the two tumblers and found that the samples contained 24
parts per million of mercury. Burr stopped using the problem
tumblers and passed the next three-day wastewater test ordered
by MCES.
“We have quit using the two tumblers
for wet processing,” said DuCharme. This has kept mercury
levels within the legal limit. As the economy and business
continues to improve DuCharme plans to replace the tumbler
linings—a cost of $6,000 each.
Prevention Tips:
Companies using or manufacturing urethane components should
use mercury-free urethanes to avoid contamination.
“I knew turning up water flow
when samples were taken was not the right way to solve the
problem. It is not fair to the environment or to the industry,”
said DuCharme.
Turning up water flow may increase
a company’s problems. Consistent differences between
test results submitted by a company and MCES can lead to increased
sampling frequency and enforcement actions.
Information about the Lumex
and Clancy
can be found on their respective Web sites.
For more information about preventing
mercury contamination, or to request a site visit from a MnTAP
engineer or scientist to get customized suggestions for your
operation, call 612.624.1300 or 800.247.0015 from greater
Minnesota.
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