ISCO of TCE-Impacted Groundwater in Bedrock through an Enhanced - - PowerPoint PPT Presentation

ISCO of TCE-Impacted Groundwater in Bedrock through an Enhanced Fracture Network

Omer J. U Uppa ppal, , Bria ian B Blum, P , P.G., K ., Kyle yle W War arren, , Erica S a Sterzin inar ar, S , Stewar art A Abram ams, s, P P.E.

PRESENTATION OUTLINE

• Site Background
• COCs, geology/hydrogeology, remedial objective

previous ISCO remedial actions/timeline

• ISCO Implementation - 2011
• Enhanced Fracture Network
• Permanganate Injections
• Post-Remediation Results
• Next Steps
• Technical Impracticability

SITE BACKGROUND

• 200-Acre Industrial R&D

Facility since the 1940s

• Trichloroethene (TCE) plume

identified in the early 1980s

• The plume occupies an area
• f approximately 3 million

square feet.

• ISRA triggered in 1996

Chatham, New Jersey U.S.G.S. Topographic Quadrangle

200 200-Acr cre S e Site w e withi hin the New ewar ark B k Basi sin` n`

INTERMEDIATE ZONE TCE PLUME

SOURCE ZONE “B” SOURCE ZONE “A”

SOURCE ZONE “B” SOURCE ZONE “A”

INTERMEDIATE ZONE TCE PLUME

SITE GEOLOGY

• Four stratigraphic units
• Glacial Till
• Saprolite
• Columnar Basalt – Target Formation
• Feltville Formation
• Vertical faults and columnar nature
• f joints likely facilitated vertical

migration of contaminants.

• Poorly connected fractures form a

complex network with low hydraulic connectivity.

SITE CONCEPTUAL MODEL

PREVIOUS REMEDIAL ACTIVITIES

• DNAPL Source Zone Pilot Tests
• Implementation of SVE Pilot

Test – 2003

• Implementation of ISCO Pilot

Test – 2003

• Blast fracture trenches

installation – 2006

• 51,024 gallons (31,320 lbs.) 2.5%

Potassium Permanganate & 10% Sodium Permanganate solution injected from 2003 to 2009

NOVEMBER 2005 JANUARY 2008

INTERMEDIATE ZONE TCE PLUME

REMEDIAL ACTIVITIES

• 9 Blast fracture trenches totaling

approximately 21,400 linear feet were installed onsite to facilitate chemical oxidant injections.

• 327 blast and injection boreholes

SEPTEMBER 2011 JANUARY 2008

INTERMEDIATE ZONE TCE PLUME

TRENCH CROSS SECTION

KMnO4/NaMnO4

TRENCH LAYOUT

ISCO INJECTION - 2011

• Additional Injections

October through November 2011

• The objective was to

mitigate the residual “source” of TCE groundwater plume with concentrations greater than 1,000 ppb.

INTERMEDIATE ZONE TCE PLUME

SEPTEMBER 2011

ISCO INJECTION - 2011

• 43,200 gallons (9,151 lbs.) 2.5%

Potassium Permanganate solution injected into 32 intermediate injection wells and 8 deep injection wells

• Hydraulic fracturing
• Injection pressures were up to

100 PSI.

ISCO INJECTION - 2011

• Techniques used to

facilitate oxidant delivery

• Specially designed
• xidant distribution

manifolds

• High pressure

wellhead assemblies

• Overnight gravity

feed injection scheme

BEDROCK INJECTION STRATEGY

• Six deep injection wells and 1

Intermediate injection well were hydro-fractured to facilitate chemical oxidant injections.

• Overnight gravity feed to facilitate

improved injection rates.

• The project scope was finished

several weeks ahead of schedule and under budget due to these aggressive injection strategies.

HYDRAULIC FRACTURING

• Fracturing of rock by a pressurized liquid
• Increases connectivity of aquifer and well yield
• Performed by Northeast Water Production, Inc.
• Direct hydraulic connection was observed at several injection wells, as a

function of water level fluctuations, water table mounding in well casings, and limited daylighting (surfacing) following hydro-fracturing.

OVERBURDEN OVERBURDEN WEATHERED BEDROCK WEATHERED BEDROCK BASALT BASALT

ISCO ACTIVITIES

TOTAL OF ALL ISCO ACTIVITIES Potassium Permanganate (lbs.) Sodium Permanganate (KMnO4 equiv. lbs.)1 10% Modified Fenton's Reagent (gallons) Pilot Test October 2003 to December 2003 4,320

• Interim Remedial Measure

June 2006 to November 2007 5,870 18,480 1,270 DNAPL Entry Zone Oxidant Placement October 2007 1,600 200

• Supplemental Injections

October to November 2009 850

• Additional Injections

October to November 2011 9,150

• Totals

21,790 18,680 1,270 GRAND TOTAL 40,470 pounds

REMEDIAL ACTION RESULTS

INTERMEDIATE ZONE

REMEDIAL ACTION RESULTS

DEEP 1 ZONE

REMEDIAL ACTION RESULTS

• Reduction in size of groundwater plume
• 71% reduction in intermediate bedrock zone
• 21% reduction in deep 1 bedrock zone
• Reduction in average TCE concentrations by

88%

• Elimination of DNAPL Source Zones
• Remaining plume TCE concentrations are

expected to decrease over time

REMEDIAL ACTION RESULTS

TECHNICAL IMPRACTABILITY WAIVER

• Groundwater contamination depth extends up to 585 feet bgs.
• Fracture diameter, spacing, orientation, vertical extent, and

connectivity within and between formations cannot be accurately determined.

• Dissolved TCE contamination has diffused into interstitial

spaces, dead-end fractures and solution voids along contaminated fracture flow paths.

• Approximately 1.6 million square feet of the plume underlies a

developed residential area.

• Limitations of subsurface remediation technologies

ONGOING ACTIVITIES

• Polishing Injection – August 2014
• Injected 2,711 gallons of 5% sodium permanganate
• 16 IW’s
• Two rounds of post-injection sampling
• Concentrations up to 30,000 ppb remaining in limited

areas approximately 100 feet into the bedrock

ONGOING ACTIVITIES…

• Planned Polishing

Injection

• Scheduled for October 2014
• Injection of 8,650 gallons of

5% sodium permanganate

• 8 converted MW’s and 21

IW’s

• Gravity feed injection
• Post-injection sampling

VIDEO

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