t19 chlorinated solvents-bienkowski

A World of Solutions

Remediation of Chlorinated Solvents in Groundwater

Lee Bienkowski, PhD, PG Jacksonville, FLApril 23, 2013

Safe Harbor Statement

This presentation contains forward-looking statements regarding CB&I and represents our expectations and beliefs concerning future events. These forward-looking statements are intended to be covered by the safe harbor for forward-looking statements provided by the Private Securities Litigation Reform Act of 1995. Forward-looking statements involve known and unknown risks and uncertainties. When considering any statements that are predictive in nature, depend upon or refer to future events or conditions, or use or contain words, terms, phrases, or expressions such as “achieve”, “forecast”, “plan”, “propose”, “strategy”, “envision”, “hope”, “will”, “continue”, “potential”, “expect”, “believe”, “anticipate”, “project”, “estimate”, “predict”, “intend”, “should”, “could”, “may”, “might”, or similar forward-looking statements, we refer you to the cautionary statements concerning risk factors and “Forward-Looking Statements” described under “Risk Factors” in Item 1A of our Annual Report filed on Form 10-K filed with the SEC for the year ended December 31, 2012, and any updates to those risk factors or “Forward-Looking Statements” included in our subsequent Quarterly Reports on Form 10-Q filed with the SEC, which cautionary statements are incorporated herein by reference.


Introduction

4A World of Solutions

Tetrachloroethene (PCE) – also known as perchloroethene, a colorless to pale yellow liquid with a pungent chloroform-like odor (Cl2C=CCl2)

Trichloroethene (TCE) – a colorless or blue-dyed liquid with a chloroform-like odor (ClCH=CCl2)

What is a Chlorinated Solvent?

PCE TCE

Cl

Cl

Cl

ClC

C


1,2-dichloroethene (1,2-DCE) – a colorless liquid with an acidic chloroform-like odor (ClCH=CHCl); comes in cis and trans isomers

Vinyl chloride (VC) – a colorless liquid or gas with a slightly sweet odor (CH2=CHCl)

More Chlorinated Solvents

1,2-DCE VC

Cl Cl Cl

H H H H

H

C C C C


PCE is used in dry cleaning and textile processing; dry cleaners are the most common source of PCE in the environment

TCE is used in degreasing metal parts and in consumer products such as white-out and carpet cleaners; auto service facilities are the most common environmental source

1,2-DCE is mostly an intermediary between other compounds; cis is more common than trans

VC is used for making polyvinyl chloride (PVC) and in the past was used as a refrigerant

Common Sources of Chlorinated Solvents


PCE – chronic ingestion of PCE in drinking water increases the risk of birth defects; it is classified as a likely human carcinogen, targeting mainly the liver and kidneys

TCE – ingestion of TCE in drinking water has been shown to impact the liver, kidneys and immune and endocrine (hormones) systems; TCE is not currently classified as a human carcinogen, but new data suggest that it may cause kidney cancer

1,2-DCE – no scientific studies have linked exposure to 1,2-DCE to health effects in humans, but rodents show decreased liver and kidney function after ingesting high concentrations

VC – vinyl chloride is classed as a known human carcinogen; it has been implicated in a rare form of liver cancer

*Source – USEPA Technology Transfer Network

Health Impacts of Chlorinated Solvents*


PCE – USEPA Maximum Contaminant Level (MCL) = 5 micrograms per liter (ug/L); Florida Groundwater Cleanup Target Level (GCTL) = 3 ug/L

TCE – USEPA MCL = 5 ug/L; GCTL = 3 ug/L 1,2-DCE – USEPA MCL cis-1,2-DCE = 70 ug/L; trans-1,2-DCE =

100 ug/L; GCTLs same as MCLs VC – USEPA MCL = 2 ug/L; GCTL = 1 ug/L

Chlorinated Hydrocarbons Environmental Standards


Reductive Dechlorination


TCE– Relative density (water = 1) – 1.5– Solubility (77o F) – 0.1%– Boiling point – 189oF– Sinks in water– Somewhat volatile

VC– Relative density (water = 1) – 0.91– Solubility (77o F) – 0.1%– Boiling point – 7oF– Rises in water– Very volatile

Physical Characteristics


Ex-Situ Methods– Pump and treat air stripping– Multiphase extraction (MPX)– Automated groundwater recirculation

In-Situ Methods– Air sparge/soil vapor extraction (AS/SVE)– In-situ oxygen curtain (iSOC)– In-situ chemical oxidation (ISCO)

– Permanganate– Peroxide– Persulfate

– In-situ nutrient enhanced bioremediation

Common Remediation Methods


Site 1 – Heckscher Drive

Remediation of TCE and PCE by Pump and Treat


Heckscher Plume Location

Jacksonville Zoo

Extent of TCE Plume 2003


Garage for servicing fleet vehicles 12,000-gallon gasoline underground storage tank (UST)

removed in 1993 Low benzene, toluene, ethylbenzene and xylenes (BTEX)

concentrations remediated by natural attenuation – no further action (NFA) in 2004

TCE and PCE detected in intermediate wells in 1994 Lithology sandy with thin clay layers to 40 feet below land

surface (bls) underlain by limestone

Heckscher Drive Background


Heckscher Site Configuration


Diffuse plume on top of limestone at 40 feet bls Maximum TCE concentration – 25 micrograms per liter (ug/L)

in DW-6 (south right-of-way of Heckscher Drive) Groundwater flow southeast toward Trout River Total plume length in 2001 was 700 feet

Initial Site Conditions


Plume extended on both sides of Heckscher Drive Toe of plume migrating toward Trout River Contamination deep; some under building High hydraulic conductivity in impacted soils Installation and operation and maintenance (O&M) expected

to cost less than injection methods

Rationale for Selecting Pump and Treat


Heckscher System Layout


Piping Installation Directional Drilling

A World of Solutions 20

Process Flow Diagram


Remediation Equipment in Compound


System startup April 2003 Initial pumping rate – 16 gallons per minute (gpm) Recovery Well (RW)-4 shut down February 2005 RW-3 shut down August 2006 RW-1 shut down October 2006 System shut down August 2008 NFA recommended November 2009 Site Rehabilitation Completion Order (SRCO) issued August

2010

System Operations


DW-1 TCE Concentrations

Mar

-00

Jul-0

0

Nov-0

0

Mar

-01

Jul-0

1

Nov-0

1

Mar

-02

Jul-0

2

Nov-0

2

Mar

-03

Jul-0

3

Nov-0

3

Mar

-04

Jul-0

4

Nov-0

4

Mar

-05

Jul-0

5

Nov-0

5

Mar

-06

Jul-0

6

Nov-0

6

Mar

-07

Jul-0

7

Nov-0

7

Mar

-08

Jul-0

8

Nov-0

8

Mar

-09

Jul-0

9

Nov-0

90.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

Date

TC

E (

ug

/L)

GCTL


System ran five years with few issues Start shutting down recovery wells after two years Reduced maximum TCE concentrations from 10 ug/L to less

than 3 ug/L Total cost of installation, maintenance and sampling –

$330,000

Conclusions


Site 2 – Jefferson StreetRemediation of TCE by In-situ Nutrient

Enhanced Bioremediation


Jefferson Site Location

Extent of TCE Plume, September 2002


Garage for servicing fleet vehicles Oil/water separator (OWS) removed in 1998 Low BTEX concentrations remediated by natural attenuation –

NFA in 2004 TCE and PCE detected in intermediate wells in 2000 Multiple sources of TCE and PCE in area Lithology sandy with thin clay layers to 35-40 feet bls

Jefferson Street Background


Jefferson Site Configuration

TCE Plume 2002


Diffuse plume on top of limestone at 35-40 feet bls Maximum TCE concentration – 35 ug/L in DW-12 Groundwater flow southeast toward St. Johns River Total plume length in 2002 – 600 feet



ISOC Pilot Test – October 2002 through April 2003– Three wells installed, each containing two iSOC units– In each well, one iSOC injected oxygen and one injected propane– Oxygen was to aid oxidation of TCE– Propane was to provide nutrients for bacteria– iSOC was not effective and was shut down

Anaerobic Biochem Plus (ABC+) Pilot Test – September 2007– Nine injection points– Each injection point was injected at four different depths– Total injection volume = 3,200 gallons of water and ABC+– TCE concentrations decreased in most wells down-gradient of

pilot test area

Pilot Testing


TCE Plume After 2007 Pilot Test


Plume extended on both sides of Jefferson Street Most impacted properties currently undeveloped Little space on source property for system High hydraulic conductivity in impacted soils Injection expected to cost less than installation and

maintenance of an active system Successful pilot test

Rationale for Selecting In Situ Bioremediation


Jefferson Injection Points – 2011


View Down-Gradient from Source Area


Injection Apparatus and Process


Injection Equipment in Action


Injection event February 2011– 120 injection points– Injected 180 gallons of ABC+ at three depths in each boring– ABC+ = bacteria, lactates, fatty acids, buffer and zero valent iron

(ZVI) Injection rate 15 gpm at 100 psi Reduced TCE in all sampled wells to <GCTL by September 2011

Injection Details


ZVI Reaction

Addition of ZVI results in lower concentrations of daughter products


TCE Concentrations 2011-2012

01/01/1

1

02/01/1

1

03/01/1

1

04/01/1

1

05/01/1

1

06/01/1

1

07/01/1

1

08/01/1

1

09/01/1

1

10/01/1

1

11/01/1

1

12/01/1

1

01/01/1

2

02/01/1

2

03/01/1

20

2

4

6

8

10

12

14

TCE

(ug/

L)

DW-12 (source area)

DW-26 (plume toe)


Iron Concentrations 2011-2012

1/1/2

011

2/1/2

011

3/1/2

011

4/1/2

011

5/1/2

011

6/1/2

011

7/1/2

011

8/1/2

011

9/1/2

011

10/1/2

011

11/1/2

011

12/1/2

011

1/1/2

012

2/1/2

012

3/1/2

012

4/1/2

012

5/1/2

012

6/1/2

012

7/1/2

012

8/1/2

012

9/1/2

012

10/1/2

012

11/1/2

012

12/1/2

0120

10,000

20,000

30,000

40,000

50,000

60,000

Iron

(ug/

L)

DW-12 (source area)

DW-29 (plume toe)


One-time injection event sufficient to remediate entire plume Reduced maximum TCE concentrations from 15 ug/L to below

detection in six months Introduced iron and other constituents required additional

monitoring Iron concentrations are decreasing to near background Total cost of injection and sampling – $265,000

Conclusions


Site 3 – Westside Skills Center

Remediation of Vinyl Chloride by Automated Groundwater Recirculation


Westside Skills Center Location

Westside Skills Center


Public vocational school built in late 1970s Provides training in culinary arts, cosmetology, and automotive

repair Six USTs removed in 1993

– USTs 1 and 2 – 10,000-gallon gasoline– USTs 3, 4, and 6 – 550-gallon heating oil– UST 5 – fiberglass OWS

Westside Skills Center Background


Westside Site Configuration

Westside Skills Center


Location of USTs 1-6


Lithology– Silty fine sand– Low hydraulic conductivity– Debris present in former OWS pit

Hardpan layer at 10 feet bls Depth to water 5 feet bls, range 1.5 feet Anaerobic conditions (dissolved oxygen <0.50 parts per

million) due to presence of hydrocarbons



Extent of PCE Plume 1993

3 ug/L

30 ug/L


Extent of Vinyl Chloride Plume 2006

1 ug/L

100 ug/L


MW-5 Concentrations 1993-20068/

1/19

9311

/1/1

993

2/1/

1994

5/1/

1994

8/1/

1994

11/1

/199

42/

1/19

955/

1/19

958/

1/19

9511

/1/1

995

2/1/

1996

5/1/

1996

8/1/

1996

11/1

/199

62/

1/19

975/

1/19

978/

1/19

9711

/1/1

997

2/1/

1998

5/1/

1998

8/1/

1998

11/1

/199

82/

1/19

995/

1/19

998/

1/19

9911

/1/1

999

2/1/

2000

5/1/

2000

8/1/

2000

11/1

/200

02/

1/20

015/

1/20

018/

1/20

0111

/1/2

001

2/1/

2002

5/1/

2002

8/1/

2002

11/1

/200

22/

1/20

035/

1/20

038/

1/20

0311

/1/2

003

2/1/

2004

5/1/

2004

8/1/

2004

11/1

/200

42/

1/20

055/

1/20

058/

1/20

0511

/1/2

005

2/1/

2006

5/1/

2006

0

50

100

150

200

250

300

350

400

PCE1,2-DCEVC


Less chance of producing vapors in classroom than AS/SVE Water table too shallow for AS/SVE More effective than MPX in low hydraulic conductivity soil In-situ methods would have required drilling through

classroom floor Recirculation less intrusive than other proposed methods

Rationale for Selecting Groundwater Recirculation


System Layout


Installation of Horizontal Recovery Well


Process Flow Diagram


System Installed


System startup June 2008 Hydrochloric acid a bi-product of VC reduction

– October 2008 pH had been reduced to below 4.0– Potassium hydroxide injection increased pH

Low flow from RWs (<0.1 gpm) Garden hose fitted to tank increased flow to 0.2 gpm

System Operations


MW-10 Concentrations 2008-2013

4/1/2

008

6/1/2

008

8/1/2

008

10/1/2

008

12/1/2

008

2/1/2

009

4/1/2

009

6/1/2

009

8/1/2

009

10/1/2

009

12/1/2

009

2/1/2

010

4/1/2

010

6/1/2

010

8/1/2

010

10/1/2

010

12/1/2

010

2/1/2

011

4/1/2

011

6/1/2

011

8/1/2

011

10/1/2

011

12/1/2

011

2/1/2

012

4/1/2

012

6/1/2

012

8/1/2

012

10/1/2

012

12/1/2

012

2/1/2

0130

200

400

600

800

1,000

1,200

1,400

1,600

1,2-DCEVC


Extent of VC Plume 2012

1 ug/L


VC Plume 2008 Versus 2012

2012

2008


System ran two years with few issues Reduced maximum VC concentration from 330 ug/L to 22 ug/L Reduced 1,2-DCE concentration from 1,500 ug/L to 100 ug/L Reduced plume extent by 80% Little rebound observed Total cost of installation, maintenance and sampling –

$300,000

Conclusions


Chlorinated hydrocarbon contamination in groundwater a common issue– Ubiquitous sources– Plumes tend to migrate long distances

Three sites – three solutions– Heckscher – Pump and treat used to prevent migration of plume

to river; effective but required 5 years to complete cleanup.– Jefferson – Nutrient enhanced bioremediation used to treat off-

site contamination; remediated TCE within 6 months, but requires additional monitoring for iron.

– Westside – Automated groundwater recirculation used to treat VC under a building; mostly effective, but would have been more successful if source removal had been conducted first.

Summary


Questions?

t19 chlorinated solvents-bienkowski

Documents

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