csm-2014 hydraulic fracturing and push-pull isco - pdf

2014 – Contaminated Site Management (CSM-2014) Sustainable Remediation & Management of Soil, Sediment and Water


AN INTEGRATED HYDRAULIC

FRACTURING AND PUSH-PULL ISCO

APPROACH FOR CRYSTALLINE

BEDROCK AQUIFER

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PRESENTATION OUTLINE

• Site Background

• Remedial Approach

• Phase I Pilot Test

• Phase II Pilot Test

• ISCO Remedy Design

• ISCO Implementation

• Conclusions


SITE BACKGROUND • 98 Acre Former Industrial R&D Facility

• Trichloroethene (TCE) impacts in soil and groundwater

Extent of TCE Plume (1 ppb)

Groundwater

Flow Direction

• Groundwater concentrations of TCE up to 59,000 ppb (PIW-1B, Nov 2011)

• Bulk of TCE impacts in the intermediate bedrock zone

• 155 tons of source area soil removed in 2006


• Unstratified Glacial Deposits

• Bedrock (Diorite)

SITE GEOLOGY

Photographer: Siim Sepp, 2005, Source: Wikipedia

Diorite fragments from well drilling

Shallow Bedrock

Intermediate Bedrock

Deep Bedrock

http://en.wikipedia.org/wiki/File:Diorite.jpg

http://en.wikipedia.org/wiki/User:Siim

http://en.wikipedia.org/wiki/User:Siim


REMEDIAL APPROACH Why Permanganate?

• Bedrock matrix had low SOD (0.5 g/kg), enabling chemical oxidation to be more cost effective.

• Known to be effective for removal of chlorinated ethenes

• Relatively short remedial timeframe

• MnO4- Relatively long subsurface

half-life (months to years)

2KMnO4 + C2HCl3 2CO2 + 2MnO2 + 3Cl- + H+ + 2K+

Permanganate MnO4

- + 4H+ + 3e- → MnO2(s) + 2H2O E° = 1.70 V


PHASE I ISCO PILOT TEST – NOVEMBER 2011

Automated Portable Bulk Feed System (Vironex)


PILOT TEST ACTIVITIES


INJECTION SUMMARY • Three injection wells

• 6,081 gallons of 2.5% potassium permanganate

• 1,260 lbs. of oxidant

• Three day operation

• 97% of solution injected into the Deep Bedrock Zone (Flow rate = 5 to 22 gpm at 60 psi)

• Shallow and Intermediate Bedrock: No measureable flow at injection pressures up to 100 psi


RADIUS OF INFLUENCE • Deep zone ROI is at least 25 feet - Observed

pink water at MW-12C.

• Observed groundwater mounding at MW-12C, MW-16B, MW-17B and MW-12D

• 99% reduction in TCE at PIW-1C, where the majority of the solution was injected

• 62% reduction in TCE at MW-12C, the directly downgradient deep monitoring well


GEOCHEMICAL PARAMETERS ORP

pH


PHASE I TESTING RESULTS

• ISCO is a feasible remedial technology for the site.

• Concentrations did not decrease significantly due to the inability to inject in the intermediate bedrock zone.

• Hydraulic fracturing needed to achieve reasonable injection rates in the intermediate bedrock zone


PHASE II ISCO PILOT TEST – APRIL 2012 Objectives:

• Obtain injection flow-pressure relationships for full-scale remedial design

• Evaluate strategies to increase chemical distribution

• Evaluate effectiveness of hydraulic fracturing to facilitate injection in the intermediate bedrock zone


FIELD IMPLEMENTATION Methodology and Operation:

• Installed an additional intermediate injection well (PIW-2B)

• Hydro-fractured PIW-2B

• Injected 2,000 gallons of 2.5% KMnO4 (452 lbs.) in PIW-2B


HYDRAULIC FRACTURING

• Fracturing of rock by a pressurized liquid

• Increases connectivity of aquifer and well yield

• Performed at PIW-2B at 100-150 bgs, where highest TCE concentrations were observed, by Northeast Water Production, Inc.

• Direct hydraulic connection was observed, as a function of water level fluctuations, between PIW-2B and PIW-1C, following hydro-fracturing.

OVERBURDEN OVERBURDEN

WEATHERED BEDROCK WEATHERED BEDROCK

DIORITE DIORITE

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INJECTION OBSERVATIONS • Hydraulic fracturing can achieve flow rates of up to 15

gpm at pressures less than 50 psi.

• Hydraulic influence was observed at distances up to 125 feet during injection.

• Groundwater daylighting was observed at PIW-1C.

Visual evidence of permanganate solution in PIW-1A


POST ISCO GROUNDWATER DATA • Oxidant distribution

at distances up to 125 feet downgradient

• Oxidant was present at several wells during the post injection sampling round

• No indication of rebound at PIW-1B

Notes:

‒ -- = Sample not collected

‒ Sampled via passive diffusion bag (PDB) samplers

‒ NJDEP GWQS for TCE = 1 ppb


PHASE II TESTING RESULTS

• ISCO is feasible for the intermediate bedrock zone.

• Hydro-fracturing can significantly enhance oxidant injection rates and distribution in the subsurface.


PUMP/WELL YIELD TESTING – APRIL 2013

• Performed at seven monitoring wells to verify achievable extraction rates that can be sustained during ISCO

• Specific capacity (step-drawdown) aquifer pumping tests - Flow rates at individual wells ranged from 0.15 to 1.5 gpm

• Constant-rate aquifer pumping test - Conducted at seven wells simultaneously at 5 gpm


FULL-SCALE ISCO REMEDY DESIGN Remedial Strategy:

• Installation of six additional intermediate bedrock zone injection wells, one extraction well

• Hydraulic fracturing of select injection wells

• ISCO with NaMnO4

• Groundwater extraction at select monitoring wells along the downgradient site boundary while injecting oxidant “Push-Pull ISCO Approach”


• Total mass of 40% NaMnO4 = 61,100 lbs.

• Target NaMnO4 injection solution concentration = 10%

• Total injection volume = 27,400 gallons

• Design injection rate = 10 gpm (over 6 hours/day)

• Design extraction rate = 3 gpm (over 8 hours/day)

INJECTION & EXTRACTION STRATEGY


INJECTIONS & EXTRACTION WELLS


EQUIPMENT LAYOUT


FULL-SCALE IMPLEMENTATION: OCTOBER – NOVEMBER 2014


INJECTION ACTIVITIES…


INJECTION VOLUMES Date Daily Total

PIW-1A PIW-1B PIW-1C PIW-2B IW-3B IW-4B IW-5B IW-6B IW-7B IW-8B (gallons)

10/16/2014 1,000 1,000

10/17/2014 1,200 1,200

10/20/2014 400 600 200 1,200

10/21/2014 1,200 1,200

10/22/2014 803 176 221 1,200

10/23/2014 779 217 296 108 1,400

10/24/2014 60 500 109 178 181 372 1,400

10/27/2014 75 900 160 180 145 140 1,600

10/28/2014 1,000 1,000

10/29/2014 1,600 1,600

10/30/2014 1,400 1,400

10/31/2014 650 200 850

11/3/2014 1,075 125 1,200

11/4/2014 1,300 1,300

11/5/2014 50 300 650 100 1,100

11/6/2014 70 665 665 1,400

11/7/2014 66 567 567 1,200

Well Total (gallons) 321 - 1,400 2,600 2,123 2,603 1,600 5,401 2,925 2,277 21,250

Proposed Volume 700 700 1,400 2,600 1,600 2,600 1,600 5,400 5,400 5,400 6,150

Injection Well


ISCO PERFORMANCE SAMPLING


GROUNDWATER SAMPLING RESULTS

Well MW-25B-1 MW-25B-2 MW-25B-3 MW-25B-4

Sampling Depth (ft bgs) 122.5 127.5 132.5 137.5

10/1/2014 1,400 440 230 200

10/20/2014 1,400 NS NS NS

10/23/2014 1,100 390 310 270

10/30/2014 850 540 280 270

Sa

mp

lin

g

Da

te

TCE Concentrations, ug/L


SIMILAR APPROACH ANOTHER SITE • TCE plume occupies an area of approximately 3 million

ft2.

• Poorly connected fractures form a complex network with low hydraulic connectivity.

• DNAPL Source Zone ISCO Pilot Test - 2003

• 9 blast fracture trenches and 327 blast/injection boreholes totaling approximately 21,400 linear feet installed to facilitate chemical oxidant injections - 2006

• 51,024 GALLONS (31,320 LBS.) OF 2.5% POTASSIUM PERMANGANATE & 10% SODIUM PERMANGANATE SOLUTION INJECTED FROM 2003 TO 2009

• 2011 RA: 43,200 GALLONS (9,151 LBS.) 2.5% POTASSIUM PERMANGANATE SOLUTION INJECTED INTO 32 INTERMEDIATE INJECTION WELLS AND 8 DEEP INJECTION WELLS – SEVERAL WELLS WERE HYDRO-FRACTURED TO FACILITATE CHEMICAL OXIDANT INJECTIONS.


BLASTING VIDEO


BLAST FRACTURE TRENCH LAYOUT

SOURCE ZONE “A”:

• 6 TRENCHES

• 2 DEEP INJECTION POINTS

• SOURCE ZONE EXCAVATION

SOURCE ZONE “B”:

• 3 TRENCHES

• 3 DEEP INJECTION POINTS


REMEDIAL ACTION RESULTS

Reduction in size of groundwater plume

Reduction in average TCE concentrations by 88%

Technical Impracticability Waiver

Substantial Cost Savings


Source: Google Maps

QUESTIONS?

csm-2014 hydraulic fracturing and push-pull isco - pdf

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