Enclosure (1) TO COMDTINST 16478.12
characterizations have focused on measuring the concentration of mercury in
the benthic sediment layers and biota attached to or near batteries.
In addition to the selection of sediments and biota to characterize, the field
sampling design had to account for variation in battery condition and
dispersal around the base of the AtoN. Batteries were routinely found in
varying states of decay, and varying locations near AtoNs. It was thought
that concomitant variations in the exposure of battery contents to the
environment and resulting measured mercury concentrations could result. The
result of the program design effort was a detailed Sediment and Aquatic Biota
Tissue Sampling and Analysis Plan (including Health and Safety Plan and
Quality Assurance and Quality Control Plan) for each prototype investigation.
The field investigation program was modeled after Superfund sampling and
analysis efforts and incorporated approved methodologies and critical Quality
Assurance/Quality Control Measures such as:
Collection and analysis of duplicate samples
Analysis of blank and spiked samples
Complete chain of custody procedures
Independent supervision of sample collection
Decontamination and sealing of all sample containers
An aquatic sampling and analysis effort, evaluating both sediment and
rganisms, was implemented at all prototype locations (Chesapeake Bay, Tampa
Bay, the Tennessee River and Puget Sound). The objective of the sediment
collection was to determine:
Whether mercury was being released from the batteries to the sediments
The extent that it accumulated and migrated
The form in which it occurred in the sediments
The investigation was designed to address these questions by collecting
sediments close to discarded batteries, at increasing distances from batteries
and AtoNs, and at background locations where batteries had never been used.
Sediment samples were collected using a tube that was carefully inserted into
the sediment. When extracted, the tube contained an undisturbed core of
sediment in the same state and configuration as it had existed on the sea
floor. This procedure allowed analysis of sediment at increasing depths to
describe mercury migration.
Sampling Densities
The number of samples and their spatial distribution addressed the general
distribution of potential contamination at AtoN sites. The sample design also
reflects NOAA's recommendation to determine the overall effects from
contamination immediately around the ATON site, not to characterize the
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