Three treatability studies were conducted, and
WP occurs in the sediments as soft, waxy parti-
the results presented in the EPA-CERCLA format.
cles of a wide range of sizes from less than 0.15 up
Geotextiles are an effective method for reducing
to 3.5 mm. The number of particles in the various
the exposure of waterfowl to WP poisonings.
size classes from small to large varies greatly
Chemical oxidation of WP in heavy ERF sediments
from one sediment sample to the next or from
is effective under certain conditions, but there is
place to place within a pond. Disturbance of con-
no simple means of mixing of the oxidant into the
taminated sediments (from traffic, wind, feeding)
heavy sediments in situ. Drying of wet contami-
results in the suspension of WP particles in the
nated sediments can eventually oxidize WP but
water column above contaminated sediments,
only at very low moisture levels, which may be
particularly where the majority of particles are in
unattainable in the field. Drying, however, may be
the small size ranges (0.15 mm or less). Sediment
a suitable treatment for dredge spoil.
cores 2030 cm deep showed that WP can be bur-
The large database being assembled on the con-
ied in the sediments to depths of 30 cm and prob-
tamination, effects, and environment of ERF was
ably more.
placed into a geographic information system. This
Waterfowl feeding in the pond bottom sedi-
permits the rapid generation of maps and dis-
ments ingest these particles as food items (or pos-
plays as well as monitoring of future changes and
sibly as gizzard grit). The ingestion by a 1-kg
related remediation actions.
duck of a single 1-mm particle (1.8 mg) can be
fatal.
Summary 19901992
WP transport. Surrogate sampling suggests that
In 1990 particles of white phosphorus (WP) in
suspended WP particles may be transported from
pond-bottom sediments were shown to be the
contaminated ponds into distributary channels
cause of the mortality of thousands of waterfowl,
connecting with the Eagle River.
documented since 1982 at Eagle River Flats, an
Although WP was not found in gizzards of 305
865-ha estuarine salt marsh and artillery range at
waterfowl shot in other Cook Inlet salt marshes,
Ft. Richardson Alaska. WP enters the pond sedi-
WP was found in the gizzards of four out of six
ments as a result of detonation of smoke projec-
teal shot on the wing in ERF and in two carcasses
tiles and is the first documented case of WP wild-
collected less than 0.5 miles from ERF, indicating
life poisonings in a U.S. Dept. of Defense Artillery
that once waterfowl ingest WP they are capable of
Training Area.
flying a limited distance.
Mortality monitoring. A simple and repeatable
Decomposing carcasses of WP-poisoned ducks
index of waterfowl mortality by which to evaluate
likely redeposit WP into the sediments.
the success of future remediation efforts was de-
Food chain risks. Predators in ERF, such as eagles,
veloped and applied during three migration peri-
ravens, and gulls, are ingesting WP-contaminated
ods using carcass and feather pile counts along
duck tissues and are likely at risk. The tissues of a
permanent transects through ponds and in the
dead eagle and a seagull egg contained WP.
adjacent woodlands.
Human health risks through consumption of
There is differential susceptibility to poisonings
ducks shot in nearby Cook Inlet marshes were
among the various species of dabbling ducks
found to be minimal based on the analysis for WP
feeding in ERF ponds. Green-winged teal, north-
in over 300 hunter-harvested duck gizzards col-
ern pintail, and mallards are frequently found
lected in September 1991.
dead, while northern shovelers and American
wigeon appear to be less susceptible. In addition to
Treatability studies. A test detonation of a high-
dabbling ducks and swans (waterfowl), several spe-
explosive projectile charge in WP-contaminated
cies of shorebirds are dying from WP poisoning.
ERF sediments did not reduce WP concentrations
and likely exacerbated the contamination prob-
WP forms and distribution. There are a large
lem. Geotextiles are an effective method for
number (75100) of small to large ponds covering
reducing the exposure of waterfowl to WP parti-
a total area of about 200 acres of ERF. However,
cles. Chemical oxidation of WP in heavy ERF sedi-
our analysis of over 1000 sediment samples for
ments is effective under certain conditions, but
WP suggests that the major contamination and
there is no simple means of mixing of the oxidant
hypothesized source of most of the waterfowl poi-
into the heavy sediments in situ.
sonings in ERF occur in two ponded areas cover-
Drying of wet contaminated sediments can
ing a combined area of about 60 acres.
eventually oxidize WP but only at very low mois-
58
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