Enclosure (1) TO COMDTINST 16478.12
after battery removal was addressed by post-removal sediment sampling. These
techniques are documented in the site investigation program results (CH2M Hill
Maughan) 1993, 1994a, 1994b, 1995). However, the primary purpose of the
sampling program was to assess the effect of spent primary batteries on human
health and the environment.
Fixed AtoNs were examined in the Chesapeake Bay, Tampa Bay, Tennessee River,
and Puget Sound. Two terrestrial locations were also examined in the Tampa
Bay area.
The Chesapeake Bay study included two visits to AtoNs. During the first
visit, a group of AtoNs was selected for survey, based on the high estimated
battery use at the AtoN, maximizing the likelihood that batteries were
present. These lights were surveyed using a remotely operated vehicle (ROV)
to document AtoN characteristics and locate batteries. Very useful data were
collected, allowing the Volpe Center to describe the dispersal of batteries at
typical AtoNs, and to identify the area where most batteries were found.
AtoNs where batteries were found were revisited to collect sediment and
biological samples. During the second visit, only AtoNs known to have
discarded batteries nearby were chosen for characterization. The Coast Guard
had conducted independent surveys of the bottoms near AtoNs in these areas,
and provided data identifying the number of batteries at each location. A
subset of this group of surveyed AtoNs was characterized in the same manner as
the AtoNs in the Chesapeake Bay; selection was based on representation of
various AtoN characteristics, including salinity, bottom type, and depths.
Research scientists designing the aquatic characterization supposed that
battery movement might result in casing deterioration with resulting low, but
detectable mercury releases around the disposal field. During the many years
following battery disposal, events such as storms and dredging have, in all
likelihood, moved the batteries from their original resting place. The
researchers hypothesized that battery movement could result in a dispersed
mercury release rather than the "concentration spots" expected by Mason and
Morel. Alternatively, some batteries remain at or near their original
position, as indicated by biologial overgrowth or burial in sediment. These
batteries were more likely to have "concentration spots" of mercury near them.
Location and variation in disposition of the batteries were studied by
sampling near batteries and at random locations in varying distances around
the AtoN base. Sediments were collected at randomly selected locations
representing 5-meter strata up to the field perimeter around the AtoN (CH2M
Hill, 1993a). The field perimeter was set at 20 meters, based on the results
of the reconnaissance of battery locations in the Chesapeake Bay.
Other phenomena, in addition to battery movement, might effect the measured
levels of mercury in sediments and biota. Just as some batteries become
buried in sediments due to sedimentation, mercury
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