t19 chlorinated solvents-bienkowski
TRANSCRIPT
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.
A World of Solutions
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
5A World of Solutions
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
6A World of Solutions
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
7A World of Solutions
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*
8A World of Solutions
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
9A World of Solutions
Reductive Dechlorination
10A World of Solutions
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
11A World of Solutions
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
A World of Solutions
Site 1 – Heckscher Drive
Remediation of TCE and PCE by Pump and Treat
13A World of Solutions
Heckscher Plume Location
Jacksonville Zoo
Extent of TCE Plume 2003
14A World of Solutions
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
15A World of Solutions
Heckscher Site Configuration
16A World of Solutions
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
17A World of Solutions
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
18A World of Solutions
Heckscher System Layout
19A World of Solutions
Piping Installation Directional Drilling
A World of Solutions 20
Process Flow Diagram
A World of Solutions 21
Remediation Equipment in Compound
22A World of Solutions
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
A World of Solutions 23
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
24A World of Solutions
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
A World of Solutions
Site 2 – Jefferson StreetRemediation of TCE by In-situ Nutrient
Enhanced Bioremediation
A World of Solutions 26
Jefferson Site Location
Extent of TCE Plume, September 2002
27A World of Solutions
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
A World of Solutions 28
Jefferson Site Configuration
TCE Plume 2002
29A World of Solutions
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
Initial Site Conditions
30A World of Solutions
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
A World of Solutions 31
TCE Plume After 2007 Pilot Test
32A World of Solutions
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
A World of Solutions 33
Jefferson Injection Points – 2011
A World of Solutions 34
View Down-Gradient from Source Area
A World of Solutions 35
Injection Apparatus and Process
A World of Solutions 36
Injection Equipment in Action
37A World of Solutions
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
A World of Solutions 38
ZVI Reaction
Addition of ZVI results in lower concentrations of daughter products
A World of Solutions 39
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)
A World of Solutions 40
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)
41A World of Solutions
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
A World of Solutions
Site 3 – Westside Skills Center
Remediation of Vinyl Chloride by Automated Groundwater Recirculation
A World of Solutions 43
Westside Skills Center Location
Westside Skills Center
44A World of Solutions
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
A World of Solutions 45
Westside Site Configuration
Westside Skills Center
A World of Solutions 46
Location of USTs 1-6
47A World of Solutions
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
Initial Site Conditions
A World of Solutions 48
Extent of PCE Plume 1993
3 ug/L
30 ug/L
A World of Solutions 49
Extent of Vinyl Chloride Plume 2006
1 ug/L
100 ug/L
A World of Solutions 50
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
51A World of Solutions
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
A World of Solutions 52
System Layout
A World of Solutions 53
Installation of Horizontal Recovery Well
A World of Solutions 54
Process Flow Diagram
A World of Solutions 55
System Installed
56A World of Solutions
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
A World of Solutions 57
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
A World of Solutions 58
Extent of VC Plume 2012
1 ug/L
A World of Solutions 59
VC Plume 2008 Versus 2012
2012
2008
60A World of Solutions
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
61A World of Solutions
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
A World of Solutions
Questions?
A World of Solutions 63