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://www.serdp-estcp.org/content/download/8159/100122/file/199712%20C&P%20(Metals).pdf
Other
Resources and Demonstrations