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

Transcription

1 ISCO of TCE-Impacted Groundwater in Bedrock through an Enhanced Fracture Network Omer J. Uppal, Brian Blum, P.G., Kyle Warren, Erica Sterzinar, Stewart Abrams, P.E.

2 PRESENTATION OUTLINE Site Background COCs, geology/hydrogeology, remedial objective previous ISCO remedial actions/timeline ISCO Implementation Enhanced Fracture Network Permanganate Injections Post-Remediation Results Next Steps Technical Impracticability

3 SITE BACKGROUND 200-Acre Industrial R&D Facility since the 1940s Trichloroethene (TCE) plume identified in the early 1980s The plume occupies an area of approximately 3 million square feet. ISRA triggered in Acre Site within the Newark Basin` Chatham, New Jersey U.S.G.S. Topographic Quadrangle

4 G:Data9\ \Cadd Data\Dwg\Powerpoint\Langan Env Wkshp\TCE Contours-Intermediate2.dwg INTERMEDIATE ZONE TCE PLUME SOURCE ZONE B SOURCE ZONE A

5 This image cannot currently be displayed. INTERMEDIATE ZONE TCE PLUME SOURCE ZONE B SOURCE ZONE A G:Data9\ \Cadd Data\Dwg\Powerpoint\Langan Env Wkshp\TCE Contours-Int Oct 2003.dwg

6 SITE GEOLOGY Four stratigraphic units Glacial Till Saprolite Columnar Basalt Target Formation Feltville Formation Vertical faults and columnar nature of joints likely facilitated vertical migration of contaminants. Poorly connected fractures form a complex network with low hydraulic connectivity.

7 SITE CONCEPTUAL MODEL

8 PREVIOUS REMEDIAL ACTIVITIES DNAPL Source Zone Pilot Tests Implementation of SVE Pilot Test 2003 Implementation of ISCO Pilot Test 2003 Blast fracture trenches installation ,024 gallons (31,320 lbs.) 2.5% Potassium Permanganate & 10% Sodium Permanganate solution injected from 2003 to 2009 INTERMEDIATE ZONE TCE PLUME NOVEMBER 2005 JANUARY 2008

9 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 INTERMEDIATE ZONE TCE PLUME JANUARY 2008 SEPTEMBER 2011

10 TRENCH CROSS SECTION KMnO 4 /NaMnO 4

11 TRENCH LAYOUT

12 ISCO INJECTION 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

13 ISCO INJECTION ,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.

14 ISCO INJECTION Techniques used to facilitate oxidant delivery Specially designed oxidant distribution manifolds High pressure wellhead assemblies Overnight gravity feed injection scheme

15 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.

16 HYDRAULIC FRACTURING OVERBURDEN WEATHERED BEDROCK OVERBURDEN WEATHERED BEDROCK BASALT BASALT 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.

17 ISCO ACTIVITIES TOTAL OF ALL ISCO ACTIVITIES Potassium Permanganate (lbs.) Sodium Permanganate (KMnO 4 equiv. lbs.) 1 10% Modified Fenton's Reagent (gallons) Pilot Test October 2003 to December , Interim Remedial Measure June 2006 to November ,870 18,480 1,270 DNAPL Entry Zone Oxidant Placement October , Supplemental Injections October to November Additional Injections October to November , Totals 21,790 18,680 1,270 GRAND TOTAL 40,470 pounds

18 REMEDIAL ACTION RESULTS INTERMEDIATE ZONE

19 REMEDIAL ACTION RESULTS DEEP 1 ZONE

20 REMEDIAL ACTION RESULTS

21 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

22 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

23 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

24 Planned Polishing Injection ONGOING ACTIVITIES 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

25 VIDEO

26 QUESTIONS?

27 THANK YOU