A. ST. MARY'S MEDICAL CENTER
1. Build Support
St. Mary's Medical Center is a 326-bed hospital located in Duluth, Minnesota.
To begin the mercury reduction project, WLSSD staff met with hospital
management to ensure their interest and commitment to the project. Once
support was assured, an existing team of hospital employees (who had already
implemented an excellent solid waste reduction program) worked with WLSSD
staff on the project.
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2. Form team
The team was made up of representatives from different areas of the hospital.
This was important because of the wide variety of different activities
performed in a hospital. Representatives from maintenance and purchasing
were particularly important. The maintenance staff has knowledge of the inner
workings of the hospital which is especially helpful when conducting
monitoring. Toxics reduction projects often require that changes be made in
the use of certain products. For this reason, a representative from the
purchasing department is essential to the team.
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3. Perform an Assessment
As a first step in the project, the mercury reduction team completed a
survey on mercury use provided by WLSSD. The survey disclosed that St. Mary's
had already replaced some mercury containing items, such as thermometers and
blood pressure cuffs, with alternative electronic devices. In addition,
mercuric chloride, a common reagent used in pathology labs, was being captured
and handled as hazardous waste instead of being flushed to the wastewater
treatment plant.
A wastewater monitoring plan was then developed to try to pinpoint mercury
sources within the hospital. Often several discharge points may enter the
sanitary sewer system from an older building like a hospital. Meeting with
maintenance staff to review old blueprints is essential before beginning a
monitoring program. Particularly in facilities that have undergone expansion,
the use of dye tablets may be needed to verify source information.
Monitoring results found mercury concentrations varying from 0.3 ppb to
1.2 ppb. The monitoring also identified the days on which mercury
concentrations were high, and where it came from in the hospital. In this
case, the monitoring results were valuable in educating the reduction team.
The team felt they had already solved their mercury problem, and did'nt
anticipate additional discharges. Once they saw the numbers, however, a
"can do" attitude quickly developed.
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4. Take Action
At this point, the mercury in the wastewater appears to be coming from the
hospital laboratories and from the laundry services. Reagents and bleach are
the suspected sources. These products are being investigated and where
possible, alternatives will be substituted. Historic sources are also under
investigation. In older buildings where there has been high mercury use in
the past, items such as broken thermometers may have been disposed of down
the drain. The mercury accumulates in waste traps and is discharged in small
amounts each time water is used. Traps in nursing stations and in the labs
are being cleaned as part of the reduction effort.
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5. Document Share Results
WLSSD staff will continue to work with St. Mary's on future reduction
efforts. New information about sources of mercury and additional wastewater monitoring results are shared with the team in regular meetings. Reductions
in mercury discharge will continue to be documented and shared.
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