SERDP Predicting DNAPL Source Zone and Plume
Response Using Site-Measured
Characteristics
Environmental
Restoration
ER-1613
Background:
The difficulty and expense associated with source-zone
and plume characterization of dense nonaqueous phase
liquid (DNAPL) represents a challenge at Department of
Defense (DoD)-contaminated sites. Identification of
cost-effective remedial options that decrease human
health and ecological risks, provide regulatory
compliance, and minimize the need for long-term
stewardship is a priority. Predicting the relationship
between DNAPL source-zone changes and down-
gradient plume response is critical to making informed
site management decisionsespecially those related to
remedial actions. Thus, it is vital that source zone and
plume characterization be conducted within a framework
that is consistent with appropriate predictive models.
Objective:
The objective of this project is to demonstrate effective
field-scale approaches that forge linkages between
characterization, prediction, and decision making at
DNAPL sites.
Process/Technology Description:
This project will develop source-strength functions,
using existing historical site data supplemented with
limited flux- and core-based sampling, for site
management purposes. Based on "a priori"
characterization of the source zone architecture,
researchers also will extend the ability to predict
DNAPL source depletion through dissolution to the
field-scale. Additionally, this project will characterize
near-source plume response to source-mass depletion to
provide the understanding needed to predict long-term
plume responses and to link characterization of the near-
source, short-term responses to likely long-term
behavior of the dissolved plume. The knowledge gained
from the field site data and experiments will be
synthesized to provide guidance on the recommended
level of source zone characterization needed to
adequately predict source-strength functions and plume
response.
Expected Benefits:
Cost-effective approaches to DNAPL site
characterization will allow DoD users and site managers
to more accurately assess the benefits of costly
aggressive source zone treatment technologies. In
addition, the accurate assessment of near-source flux
changes and the magnitude of "back diffusion" expected
will help DoD by avoiding costly remedial efforts with
inadequate benefits. Also, guidelines will be produced
on site characterization to provide an established
methodology for defining the source strength function
and how it defines predicted plume responses.
(Anticipated Project Completion - 2012)
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