active artillery impact area, Eagle River Flats,
A simple field screening method to detect white
Alaska. USA Cold Regions Research and Engi-
phosphorus particles in sediment is described. A
thin layer of wet sediment is heated until all water
neering Laboratory, Special Report 9622.
evaporates. The presence of white phosphorus is
Remediation of sediments in permanently
indicated by visual detection of the inflammation
ponded areas at Eagle River Flats, a salt marsh
of white phosphorus particles that occurs at rela-
contaminated with white phosphorus (WP),
tively low temperatures (less than 40oC) once a
may require dredging. Because the Flats were
protective layer of water is removed. The field
used as a firing range impact area for over 40
screening method consistently gave positive
years by the U.S. military, there is much unex-
results for samples where solvent extraction fol-
ploded ordnance, which will require that any
lowed by gas chromatography indicated white
dredging equipment be remotely controlled. To
phosphorus concentrations above 1 g/g. A more
treat the sediment pumped from dredged areas, a
sophisticated method, based on solid-phase
spoils retention basin was designed, constructed,
microextraction and gas chromatography deter-
and tested. This basin contains several innova-
mination, was also tested. Concentrations less
tions, including a natural peaty-silt liner and a
than 1 g/kg were detectable.
geofabric barrier to inhibit reintroduction of
WP into the environment, and is designed for the
natural remediation of the WP. The dredging sys-
Walsh, M.E., S. Taylor, and P.G. Thorne (1996)
tem was deployed in October of 1994, with sam-
Development of an analytical method for white
phosphorus (P4) in water and sediment using
pling indicating that WP-contaminated areas
solid-phase microextraction. USA Cold Regions
were removed from the dredged area. An early
Research and Engineering Laboratory, Special
snowfall curtailed operations shortly after initia-
Report 9616.
tion.
Headspace solid-phase microextraction (SPME)
methods were developed for white phosphorus in
Walsh, M.R., and C.M. Collins (1998) Dredging
water and sediment/soil to minimize waste gen-
as remediation for white phosphorus contamina-
erated by methods based on solvent extraction.
tion at Eagle River Flats, Alaska. USA Cold
Headspace SPME provided a rapid, nonexhaustive
Regions Research and Engineering Laboratory,
extraction, based on equilibrium, of white phospho-
CRREL Report 985.
rus. Comparison of results obtained by headspace
The Eagle River Flats impact area is a Ft. Rich-
SPME and solvent extraction shows that head-
ardson Superfund site. It is a salt marsh that is
space SPME may be used quantitatively for some
contaminated with white phosphorus (WP), and
water matrices and qualitatively for more complex
remediation of sediments in permanently pond-
matrices such as sediment/soil. Because detection
ed areas may require dredging. A remotely pilot-
limits appear to be similar to those obtained by
ed dredging system was designed, constructed,
solvent extraction, headspace SPME can be used to
and deployed at the Flats as part of the overall
rapidly screen samples for contamination, elimi-
site remediation feasibility study. Experience
nating the need to solvent-extract most samples.
gained over 2 years of engineering study and
contract operation indicates that, although feasi-
ble and effective, this alternative is slow, difficult,
Walsh, M.R., E.J. Chamberlain, K.S. Henry, D.E.
Garfield, and E. Sorenson (1996) Dredging in an
and very expensive.
THESES
ior of particulate P4 in unsaturated sediments is
Hansen, T.A. (1995) The persistence of white
valuable in the development of remediation
phosphorus in unsaturated sediments. Master of
plans and estimations of persistence of P4 in sedi-
Science, Dartmouth College.
Particulate white phosphorus (P4) contamina-
ments.
tion is the cause of catastrophic waterfowl dieoffs
To gain insight into P4 persistence, particulate
at Eagle River Flats, Alaska. As this is the first
P4 persistence in unsaturated sediments was
documented case of P4 persistence in sediments,
modeled. Modeled processes include the subli-
little knowledge regarding processes affecting
mation of solid P4 to vapor, the diffusion and
persistence is available. Knowledge of the behav-
chemical reaction of P4 vapor and oxygen, the
88
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