T19 chlorinated solvents-bienkowski

A World of Solutions
Remediation of Chlorinated Solvents
in Groundwater
Lee Bienkowski, PhD, PG
Jacksonville, FL
April 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”, “conti
nue”, “potential”, “expect”, “believe”, “anticipate”, “project”, “estimate”, “predict”, “i
ntend”, “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

3A 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
Cl
C
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 19
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
0.0
2.0
4.0
6.0
8.0
10.0
12.0
14.0
TCE(ug/L)
Date
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 Street
Remediation 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
0
2
4
6
8
10
12
14
TCE(ug/L)
DW-12 (source area)
DW-26 (plume toe)

Iron Concentrations 2011-2012
0
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 1993-2006
0
50
100
150
200
250
300
350
400
8/1/1993
12/1/1993
4/1/1994
8/1/1994
12/1/1994
4/1/1995
8/1/1995
12/1/1995
4/1/1996
8/1/1996
12/1/1996
4/1/1997
8/1/1997
12/1/1997
4/1/1998
8/1/1998
12/1/1998
4/1/1999
8/1/1999
12/1/1999
4/1/2000
8/1/2000
12/1/2000
4/1/2001
8/1/2001
12/1/2001
4/1/2002
8/1/2002
12/1/2002
4/1/2003
8/1/2003
12/1/2003
4/1/2004
8/1/2004
12/1/2004
4/1/2005
8/1/2005
12/1/2005
4/1/2006
PCE
1,2-DCE
VC

 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
0
200
400
600
800
1,000
1,200
1,400
1,600
4/1/2008
6/1/2008
8/1/2008
10/1/20…
12/1/20…
2/1/2009
4/1/2009
6/1/2009
8/1/2009
10/1/20…
12/1/20…
2/1/2010
4/1/2010
6/1/2010
8/1/2010
10/1/20…
12/1/20…
2/1/2011
4/1/2011
6/1/2011
8/1/2011
10/1/20…
12/1/20…
2/1/2012
4/1/2012
6/1/2012
8/1/2012
10/1/20…
12/1/20…
2/1/2013
1,2-DCE
VC

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

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