1. Former NAS Moffett Field
Site 26 Eastside Aquifer Treatment System
Neil Hey, PG
Shaw Environmental, Inc.
Valerie Harris, PE
Harris
Navy BRAC PMO West
September 8, 2011
S t b 8
RAB Meeting
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2. Presentation Overview
• Treatability Study Update
• Focused Feasibility Study
• Schedule
• Questions
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3. Site 26 Treatability Study - Location
Note – inset location not to scale
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4. Treatability Study Purpose
Evaluate the applicability and effectiveness of
EHC®, an in situ abiotic/biotic treatment
technology,
technology to reduce the chemicals of concern
(COC; PCE, TCE, DCE, & VC) concentrations in
g
groundwater to levels below the ROD cleanup p
standards at IR Site 26
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5. EHC® Treatment Technology
• A product of Adventus Americas, Inc.
• Patented combination of zero-valent iron (ZVI)
zero valent
particles & plant-based carbon
• Combination of chemical (abiotic) and biological
(biotic) reductive dechlorination processes
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6. Project Description
• Installed 5
observation wells
• Injected EHC® at
16 locations
• Performed 10
post-injection
groundwater
monitoring events
g
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7. EHC® Injection
Site Location
Total CEs ~80
µg/L
50 ft x 50 ft area
40 to 8 feet bgs
~6,600 gallons
6,600
hydrant water
~23,000
~23 000 pounds
EHC® Groundwater
Flow
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8. Treatment Area Results
82 µg/L total
4 µg/L total 2 µg/L total
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9. Treatment Area Results
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10. TS Conclusions
• EHC® easy to prepare but difficult to inject
• EHC® not di t ib t d uniformly due to h t
t distributed if l d t heterogeneous
nature of subsurface
• Complete reductive dechlorination observed in all
treatment area wells
• 98% reduction in total COCs concentration in treatment
area
• PCE, TCE, & DCE concentrations in treatment area
reduced below ROD cleanup standards in < 1 year
• Vinyl hl id
Vi l chloride concentration in treatment area remains
i i i
slightly above ROD cleanup standard but decreasing
• EHC® continues to treat on-flow of COCs 2 years after
y
treatment
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11. Focused Feasibility Study
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12. Site 26 Background
• Chlorinated solvents identified in groundwater near
Hangar 3 in 1983
• Record of decision (ROD) signed in 1996. Selected
remedy was groundwater extraction and treatment
to restore groundwater to cleanup standards.
• Cleanup standards – drinking water
– Tetrachloroethene (PCE) = 5 g/L
– Trichloroethene (TCE) = 5 g/L
–CCis-1,2-dichloroethene = 6 g/L
2 d hl h /
– Vinyl chloride = 0.5 g/L
12

13. Site 26 Background (continued)
• Eastside Aquifer Treatment System (EATS) began
q y ( ) g
operating in 1999.
– extracted 67 million gallons of water
– removed 23.7 pounds of chlorinated volatile organic
compounds (VOCs)
• Shut down in 2003 to evaluate:
– Evaluate plume stability
– Chemical rebound
– Natural attenuation
– HRC in plume hot spots
– Treatability study (almost completed)
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14. 2010 Groundwater Plume
Combined CVOC concentrations
• 85.9 g/L (maximum)
located near current treatability
study
• Max combined CVOC
concentration in other areas
about 25 g/L
b t /
TREATABILITY STUDY AREA
Groundwater
Flow
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15. Focused Feasibility Study
Purpose – to evaluate several technologies along with
the selected remedy
• Identify remedial action objectives and applicable
regulations
• Identify and screen treatment technologies
– Monitored Natural Attenuation
– Abiotic/Biotic Treatment (EHC®)
– In Situ Biostimulation/Bioaugmentation
• Develop and evaluate remedial alternatives against
seven of the nine NCP criteria
• Compare the remedial alternatives against each other
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16. Preliminary Remedial Alternatives
• Alternative 1 – No Action
• Alternative 2 – Monitored Natural Attenuation
(MNA)
• Alternative 3 – Optimized Pump and Treat
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17. Preliminary Remedial Alternatives
• Alternative 4 – Abiotic/biotic Treatment and
MNA
• Alternative 5 – In Situ Biostimulation
/Bioaugmentation and MNA
/Bi t ti d
Biotic PCE
TCE
Cis 1,2‐DCE Trans 1,2‐DCE
VC
Ethene
Ethane
α‐elimination 17
β‐elimination

18. Conceptual Treatment Areas
•Trend analysis
performed for
each well
•Identify areas
th t could b
that ld benefit
fit
from treatment
Natural
processes =
60 years Natural
processes >
60 years
(increasing
trend/no
trend)
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19. Sustainability
• An evaluation of sustainability will be included
in the feasibility study (FS)
• FS will use SiteWiseTM
– Streamlined life cycle analysis tool
life-cycle
– Developed by Navy, Army Corps and Battelle
– Available at http://www.ert2.org/t2gsrportal
• Sustainability metrics considered are:
– Energy and resource consumption
gy p
– Greenhouse gas and criteria pollutant emissions
– Water and ecological impacts
– Worker and community safety
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20. Schedule
• November 30, 2011- Draft FS Report
p
• December 1, 2011 to January 29,
2011 – Agency/RAB Review of draft
g y/
• April 30, 2012 - Final FS Report
Next Steps
– Proposed plan
– ROD amendment
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21. Questions?
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