ECONOMICS AND VALUATION OF BIOAUGMENTATION - Bioaugmentation for Groundwater Remediation - page 313

Additional costs associated with injection of a bioaugmentation culture include delivery of
the culture vessels to the site, purchase or rental of additional equipment required for the
bioaugmentation process, and labor for the field technicians. These costs are generally small
relative to costs for injection of electron donor. The cost of injection equipment and related
activities will vary depending on the volume of culture being injected, but for a typical, medium
sized application of 80 L of culture, these costs may add $50-$100 per liter to the cost of
bioaugmentation (Jeff Roberts, SiREM Laboratories, personal communication, 2010).
A rough planning level cost estimate for bioaugmentation can be developed based on the
information presented in this chapter. Assuming that 1 L of culture is used to bioaugment
35,000 L of groundwater, the culture costs $200 per liter to purchase and $100 per liter to inject,
and the porosity is 30%, the cost to bioaugment a site would be $2.60/m 3 of aquifer (roughly
$2.00/cubic yard).
11.3.2 Value of Bioaugmentation Relative to a “Wait and See”
Approach to Degradation of DCE and VC
As stated earlier, the key potential economic benefits or value of bioaugmentation are:
(1) reduction in the time required to achieve complete dechlorination of chlorinated solvents
(or complete degradation of other target compounds), thereby reducing the overall costs for
injection of electron donor (or capturing more of the value of the electron donor initially
injected) and groundwater monitoring; (2) reduction in regulatory oversight by achieving
treatment objectives sooner; (3) reduction in the time required to return the groundwater to
beneficial use by achieving treatment goals in a shorter period of time; and (4) the ability
to apply EISB at sites where bioremediation would not be effective otherwise, and where other
more expensive approaches would be required.
It is difficult to quantify the actual cost savings or value of these benefits, but the
magnitude can be significant. Reducing the time to achieve degradation also has the potential
to reduce other costs. These costs may be associated with increased monitoring or evaluation of
risks that may be considered necessary by site owners, regulators or other stakeholders if EISB
is not meeting goals in a timely fashion. Every site will be different and it is not possible to
predict what these additional costs may be, but it is clear that site owners, regulators, and other
stakeholders are likely to be more confident that the EISB application will be successful if they
see data showing complete degradation soon after EISB is implemented.
The “Principles and Practices of Enhanced Anaerobic Bioremediation of Chlorinated
Solvents” (AFCEE et al., 2004 ) states that, “it has been observed at numerous locations that
dechlorination species require as long as 12-36 months of substrate addition to grow to
concentrations that provide timely and complete dechlorination of dichloroethene (DCE) and
VC to ethene.” The document later states that, “bioaugmentation can shorten lag times or
improve the rate of dechlorination in environments where native dechlorinating species are
poorly distributed, present at low population densities, or not an ideal strain.”
There are no definitive tools that can quantitatively predict how much a specific remedia-
tion time frame can be reduced through the use of bioaugmentation. However, given that the
time to achieve remedial objectives with bioaugmentation can be on the order of months to
several years (AFCEE, 2004 ), significant cost savings can result from shortening the duration
of active treatment (Dennis et al., 2009 ). The potential cost savings to consider when evaluating
bioaugmentation include:
1. Reducing the cost to purchase and inject electron donor . If aggressive treatment of
a targeted key area is being conducted and it is expected that 5 years of active addition