Benthic Flux Sampling Device
Description
The Benthic Flux Sampling Device (BFSD) is an
instrument for measuring the flux rates (i.e., rates of change or movement) of contaminants in sediment. (Benthic refers to a
narrow zone of water and sediment at the bottom of a body of surface water.) Benthic organisms are bottom
feeders and the small organisms that live in sediment. The BFSD collects
samples from a sealed volume of water at the sediment/water interface for 2 to
4 days. A flux rate is measured by analyzing the samples for an increase or
decrease in contaminant concentration. Increases in concentration indicate that
the contaminant is moving out of the sediment; decreases in concentration
indicate that the contaminant is moving into the sediment.
Limitations and Concerns
Sampling with this device should be followed
with more thorough analysis if contaminants are indicated.
The results should not be relied on to provide
information on ecological effects.
Applicability
BFSD is an on-site screening tool used to determine
whether contamination in sediments is moving to surface water. It is primarily
used to detect the presence of heavy metals (e.g., lead, mercury, chromium,
zinc, and copper), polychlorinated biphenyls (PCBs), dioxins, and petroleum products. It can be
used to help determine whether dredging will increase environmental risks or if
contaminants are being deposited in the sediment from surface waters.
Technology Status
The technology and methods are well developed.
They can be considered commercial.
Web Links
http://costperformance.org/monitoring/pdf/metalinsediments_2.pdf
http://www.serdp-estcp.org/content/download/8158/100114/file/ER-199712-C&P.pdf
http://t2.serdp-estcp.org/t2template.html#tool=BFSDDS&page=Intro
Other Resources and Demonstrations
See
https://ert2.navfac.navy.mil/printfriendly.aspx?tool=contaminatedsediment
for documents on contaminated sediment.