Biomedical Engineering Reference
In-Depth Information
It is assumed that it will take 5 years to reach remedial goals using EISB. Each application
of EVO will support dechlorination for 2-3 years, so a second application of EVO will be
required part way through the third year. The second application will deliver 100% of the initial
EVO loading using the same injection well network. No bioaugmentation will be necessary
during the second injection. No other operation and maintenance is required with this remedial
option. Quarterly monitoring will be performed for the first 5 years, followed by semi-annual
monitoring for another 5 years. The quarterly monitoring will include parameters specific to the
remedy, such as total organic carbon (TOC) and other relevant monitored natural attenuation
(MNA) analytes. The semi-annual sampling will include only volatile organic compounds
(VOCs).
In Case 2, EISB will be applied as a barrier, with the objective of reducing the contaminant
concentrations by 90-95% before leaving the site. It is assumed the barrier will need to operate
for 30 years. Five 5-cm (2-inch) diameter monitoring wells will be installed. EVO will be used as
the electron donor to promote reductive dechlorination of chlorinated VOCs within the zone of
influence of the shallow barrier. The EVO will be applied through a single row of 15 injection
wells spaced on 5-m (16.4 ft) centers along the length of the shallow barrier. The 5-cm (2-inch)
diameter injection wells will be screened across the saturated zone and developed prior to EVO
injection. Pre-design injection testing will be used to verify the injection rate, which is assumed
to be 10 L/min (2.6 gpm). EVO (185 kg [407 lb]) will be added to each injection point, along with
9,000 L (2,376 gal) of fluid (dilute EVO and chase water) to ensure complete distribution of the
EVO. EVO will be added in the same manner described in Case 1. The injections will be
performed by a two-person crew and will require 11 days, including set-up and breakdown.
Bioaugmentation will be conducted along with the first injection of electron donor to
provide maximum distribution of the initial culture and minimize additional costs for injection.
The injection will be conducted following the same procedure as for Case 1.
Each application of EVO will support dechlorination for 2-3 years, so that an additional
application of EVO will be conducted every 3 years. These subsequent applications will deliver
100% of the initial EVO loading utilizing the same injection well network. No bioaugmentation
will be necessary after the first injection. No other O&M is required with this remedial option.
Quarterly monitoring will be performed for the first 5 years, followed by semi-annual moni-
toring thereafter. Both the quarterly and semi-annual monitoring will include parameters
specific to the remedy, such as TOC and other relevant MNA analytes.
In Case 3, EISB also will be applied as a barrier using EVO with the objective of reducing the
contaminant concentrations by 90-95% before leaving the site, but the barrier depth will be
greater than in Case 2. The EVO will be applied through a single row of 15 paired injection wells
spaced on 5 m (16.4 ft) centers along the length of the deep barrier. A groundwater model will be
utilized in the design phase to verify well spacing and ensure flow will pass through the barrier.
Each set of paired wells will consist of two 5-cm (2-inch) diameter injection wells, one screened
across the upper 4.5 m (14.8 ft) of the saturated zone and the second screened across the lower
4.5 m (14.8 ft). All the wells will be developed prior to EVO injection. Pre-design injection testing
will be used to verify the injection rate, which is assumed to be 10 L/min (2.6 gpm). Commercial
EVO solution (280 kg or 616 lb) will be added to each injection point, along with 13,500 L
(3,564 gal) of fluid (dilute EVO and anaerobic chase water) to ensure complete distribution of
the EVO. EVO will be added in the same manner described in Case 1. The injections will be
performed by a two-person crew and will require 24 days, including set-up and breakdown.
Bioaugmentation will be conducted along with the first injection of electron donor to
provide maximum distribution of the initial culture and minimize additional costs for injection.
The injection will be conducted following the same procedure as for Case 1 and 2.
It is expected that each application of EVOwill support dechlorination for 2-3 years; therefore,
an additional application of EVO will be conducted every 3 years. These subsequent applications
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