Enclosure (1) TO COMDTINST 16478.12
The sediment and biotic sampling sistes for the Puget Sound study were chose
from Budd Inlet, which is a shallow estuary at the extreme southern end of
Puget Sound. Located north of the city of Olympia, Budd Inlet is the majro
waterway connecting Olympia and Tumwater, and the Deschutes River is its major
freshwater source. The inlet is approximately 6.9 miles long, with an average
width of 1.15 miles and a maximum width of 1.61 miles. It is a partially
mixed shallow estuary with muddy substrates. The average depth is 27 feet at
mean low water. The shoreline and intertidal areas are moderately steep, and
only the intertidal mud flats are located at the southern end of the inlet
near Olympia Harbor. Puget Sound enters Budd Inlet through the Tacoma Narrows
and Dana Passage, and is diluted at the inlet head by the Deschutes River.
Water properties in Budd Inlet refelct these saltwater and freshwater sources.
At times of high runoff, a surface layer of low-salinity water is observed in
the inlet.
Development of Sampling Design
Environmental risk assessments involve numerous and complex receptors,
endpoints, levels of acceptable risk, and methods of estimating risk. As a
result of the complexity, there is no standard set of procedures applicable to
all situations. Reference books on the subject strongly recommend a phased
approach to environmental risk assessment. For instance, EPA guidance (EPA
1993) recommends a phased investigation allowing for the identification of
potential problem areas before conducting detailed investigations of specific
environmental media and receptors. This phased approach focuses attention and
resources on areas of potential risk, eliminating media and receptors
determined to be of no risk based on adequate data and simple screening
techniques.
The environmental characterizations were designed to measure two types of AtoN
battery risk; the direct effect on humans due to ingestion of mercury, and the
environmental risk due to mercury releases into nearby sediments. If evident,
human health risk results inhalation of mercury vapor or from bioaccumulation
of mercury-i.e., consumption of marine animals that consume smaller biota
contaminated with mercury from batteries. Environmental risks to the
biological community in nearby sediment at AtoNs results from release of the
contents of spent batteries. These two types of risk are inter-related since
lower-level organisms are the food of higher-level (trophic) organisms, and
evaluation of the impact on the benthic community translates into an estimate
of broader marine animal effects.
Benthic biota and attached organisms were chosen for study to evaluate both
human health and environmental risk because they were the best indicators of
battery-specific effects. While humans normally consume larger marine
animals, analysis of these species alone is an insufficient indicator of
bioaccumulation risk directly attributable to mercury releases from spent
batteries. The aquatic
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