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Groundwater Remediation: Combining Solar Technology with
Sustained and Controlled Release Reactants to Create Low-Cost, Low-
Maintenance, and Green Reactive Interceptor Zones
Lindsay Swearingen and Jason Swearingen
Specialty Earth Sciences, LLC
Abstract
The environmental science community has a collective interest in identifying viable and sustainable remedial
solutions for groundwater contaminant plumes which reduce carbon footprint, minimize waste generation,
and limit energy inputs required for remediation implementation, operations, and ongoing maintenance. DOE
and DOD sites in particular could benefit from Greener Cleanup technologies, especially in light of future
requirements to remediate vast dissolved phase plumes of emerging contaminants of concern such as 1,4-
Dioxane.
Sustained and Controlled Release reactant technology involves coating or encapsulating environmental
reactant materials to facilitate more efficient and user-friendly in situ remediation implementation. The result
is a passive approach to ground water remediation. Common problems encountered with traditional liquid
injection applications which lead to contaminant rebound and the need for multiple mobilizations are
addressed with this new approach. Sustained Release reactant technology harnesses the energy of
concentration gradient driven diffusion as well as natural groundwater movement to deliver oxidants in the
subsurface over long periods of time (years). These materials can be applied to the subsurface in a number
of forms and methods.
Sustained and Controlled Release reactant technology can be combined with solar technologies, for
example, to allow for wider spacing of reactant installation locations. A project will be featured where solar
powered pumps and programmed controls were used in conjunction with SOCORE encapsulated potassium
permanganate materials to enhance sub-surface mixing and distribution of oxidant. The result was the
construction of an effective, low-cost, low-maintenance, and sustained reactive zone to intercept a dissolved
phase CVOC contaminant plume migrating from an upgradient source area at the site. The system was
installed in June 2013 at a cost of less than $75,000 and has been in operation for over 2.5 years. The first
SOCORE permanganate material recharge event at an estimated cost of $10,000 is now due to occur.
Site Background
• After extensive Free Product Recovery activities and limited source excavation, 2 failed
RegenOx injections, client seeks cost-effective and low-impact remedial strategy utilizing
existing infrastructure
• PCE, TCE, DCE, VC impacted fill underlain by LPM clay formation
• Site logistics:
• Active industrial facility
• Remaining source zone soils are located at building foundation and adjacent to
sewer utilities.
Objectives
• Intercept contaminant migration from ongoing source area located beneath
the building footprint.
• Implement a remedial approach that addresses long-term, down-gradient
impacts from un-treated source area
• Reduce COC concentrations in groundwater at target monitoring well (MW-
10)
• No remedial activities allowed within the facility building or beneath the
building footprint
• Quick deployment with minimal site disruption
• Very limited remediation budget for initial activities and minimum funding
available for ongoing O&M or repeat events
• Utilize existing injection infrastructure, if possible, to reduce costs
Methods
3-Phase Remedial Implementation:
Materials
Results
Conclusions
• The result was the construction of an effective, low-cost, low-maintenance,
and sustained reactive zone to intercept a dissolved phase CVOC
contaminant plume migrating from an up-gradient source area at the site.
• The system was installed in June 2013 at a cost of less than $75,000
• The system has been in operation for over 2.5 years. The first SOCORE
permanganate material re-charge was performed in August 2016 at a cost of
less than $10,000.
Target MW-10:
PCE – 40,000 ug/L
TCE – 22,000 ug/L
DCE – 50,000 ug/L
VC – 4,000 ug/L
1) Injection – 40 gal of 10% NaMnO4
injected at each of 10 DPT boreholes from
4’-10’ bgs (top down), followed by 25 gallon
chase injections of clean water to assist
distribution. DPT boreholes placed on 3-foot
spacings.
2) SOCORE – Each DPT borehole was
completed with 2” ID PVC piezometer,
screened from 2’-12” bgs target interval..
Four (4) SOCORE Permanganate cylinders
with holders were deployed from 2’ -12’ bgs
at each piezometer location, for a total of
forty (40) 1.35-in x 2 ft SOCORE
Permanganate cylinders.
3) Recirculation – To aid and
accelerate permanganate
distribution across the reactive
interceptor zone, a low-flow
solar-powered recirculation
system was also constructed
and installed, including: piston
pump, manifolds, solenoid
valves, programmable timer,
and re-circulation lines.
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COC Monitoring Data at Target Well
Vinyl chloride Trichloro-
ethene
Tetrachloroethene (cis) 1,2-Dichloroethene Total Targeted VOs:
Date
VC
(ug/L)
TCE
(ug/L)
PCE
(ug/L)
DCE
(ug/L)
Total
Targeted
VOC’s
(ug/L)
6/27/12 3,880 17,000 61,600 43,900 126,380
7/31/12 4,100 17,000 60,000 36,000 117,100
9/18/12 ND 19,000 63,000 10,000 92,000
12/12/12 1,500 16,000 55,000 18,000 89,000
6/6/13 4,000 22,000 40,000 50,000 116,000
7/18/13 1,400 15,000 33,000 25,000 74,400
9/23/13 550 6,100 27,000 11,000 44,650
12/6/13 1,900 15,000 42,000 31,000 89,900
4/4/14 350 1,100 1,600 6,700 9,750
6/4/14 1,400 1,900 3,400 9,900 16,600
9/4/14 2,200 7,300 22,000 12,000 43,500
12/5/14 24 140 520 810 1,494
3/3/15 170 700 1,900 4,300 7,070
6/8/15 180 340 790 1,700 3,010
9/2/15 3,800 16,000 9,100 32,000 60,900
Baseline
2 year data
Remediation
Implementation
Re-charge
Event Due
SOCORE Permanganate Cylinders & Holders
Solar-powered
recirculation system
Specialty Earth Sciences
www.sesciences.com
Spent SOCORE cylinder
(ug/L)