Extraction Of Contaminant Source Information From Site
Source A
Source B
Copyright© 2012, AECOM. All rights reserved.
From Site Investigation Data
National Conference of Environmental Monitoring
August 7, 2013
San Antonio, Texas
Jun Lu, PhD
Site Investigation Data
• Site history
• Geological/hydrogeological data
– Borehole lithology correlation and cross
sections
– Groundwater flow
• Fluid level gauging
• Effective porosity• Effective porosity
• Hydraulic conductivity
• High resolution site characterization data
– Membrane interface probe (MIP)
– Laser induced fluorescence (LIF)
• Laboratory analytical data
Laboratory Analytical Data
• Contaminant Concentration Data
– Spatial patterns
– Temporal trends
– Diagnostic ratios and correlations
– Phase equilibrium
– Mass flux and discharge
• Geochemical parameters
• Compound specific isotope analysis (CSIA)
Spatial Pattern
Temporal Trend
Diagnostic Ratios and Correlations
• BTEX
• Oxygenates
– MTBE and TBA
• PAHs
– P/A; FL/PY; BaP/BeP; BbF/BkF; BaA/C;
Per/BaPPer/BaP
• Chlorinated solvents
– TCA and 1,1-DCE
• Metals/semi-metals
Page 6
Diagnostic Ratios and Correlations - Examples
2.01.51.00.50.0
25
20
15
10
5
0
FL/PY
P/A
T-SB-3/ 5- 6.5
T-SB-3/ 7.5- 9T-F5/ 2.5- 4
T-F4/ 5- 6.5T-E1/ 5.5- 6.5
T-A6/ 2.5- 4
T-F2/ .5- 2 D.A-062910
T-C4/ 6.5- 8
T-SB-6/ 0- 1.5
T-F1/ 5- 6.5
CB6-OF-0910
T-D6/ 3.5- 5
CB5-I -0855
CB6-OF-0500
T-C8/ 2.5- 4
MW-12-DOE
CB3-O-0910
CB5-O-0910
CB5-O-0610
CB3-O-0610
SB57b
T-F3/ 5- 6.5
T-C7/ 3.5- 5
SB58
T-C6/ 5- 6.5
CB2-O-0610
T-SB-3/ 0- 1.5
T-B2/ 12.5- 14
T-C3/ 3.5- 5
T-C6/ 8- 9.5
T-D6/ 6.5- 8
T-SB-2/ 2.5- 4
T-C4/ 5- 6.5
CB6-I-0710
T-SB-2/ 0- 1.5
T-B4/ 5- 6.5
T-C6/ 6.5- 8
T-C1/ 2.5- 4
T-D6/ 5- 6.5
T-SB-3/ 2.5- 4
T-B1/ 1- 2.5
T-E2/ .6- 2
CB2-O-0910
T-SB-4/ 5- 6.5
T-E1/ 5- 5.5
T-B4/ 2.5- 4
T-D6/ 2- 3.5
T-E1/ 3.5- 5
T-C4/ 3.5- 5
MW-12-DOE
Figure 1 - P/A vs FL/PY
Page 7
2.01.51.00.50.0
1.2
1.0
0.8
0.6
0.4
0.2
FL/PY
BaA/C
D.A-062910
CB-6-OF-0910
I -CB6-0710
CB6 Of-0500
CB-5-O-0910
I -CB5-0855
O-CB5-0610
CB-3-O-0910
I -CB3-0710
O-CB3-0610
CB-2-O-0910
O-CB2-0610
T-SB-1/ 0- 1.5
T-DS-1/ 0- .5 T-F5/ 5- 6.5
T-F4/ 5- 6.5
T-F4/ .5- 2
T-F5/ 2.5- 4
T-F2/ .5- 2
T-E3/ .5- 2
T-C4/ 6.5- 8
T-A6/ .5- 2
T-F8/ 2.5- 4
T-F3/ 5- 6.5
T-F1/ 5- 6.5
T-E1/ 5.5- 6.5
SB60
SB58
T-SB-1/ 12.5- 14
T-F5/ .5- 2
T-F2/ 5- 6.5
T-F2/ 2.5- 4
T-F1/ 2.5- 4
T-D5/ 1- 2.5
T-C6/ 3.5- 5
T-C2/ 2.5- 4
T-B2/ 12.5- 14
T-A6/ 2.5- 4
SB57b
T-SB-6/ 2.5- 4
T-D10/ .5- 2
T-C7/ 7.5- 9
T-B4/ 5- 6.5
T-D1/ 1- 2.5
T-C4/ 5- 6.5
T-C3/ 3.5- 5
MW-12-DOE
T-SB-3/ 5- 6.5
T-D6/ 3.5- 5
T-C8/ .5- 2
T-C6/ 5- 6.5
T-SB-5/ 0- 1.5
T-B4/ 2.5- 4
T-SB-6/ 0- 1.5
T-SB-2/ 2.5- 4
T-D6/ 6.5- 8
T-C8/ 2.5- 4
T-C6/ 8- 9.5
T-D6/ 5- 6.5
T-SB-3/ 7.5- 9T-SB-3/ 0- 1.5
T-C7/ 3.5- 5
T-C1/ 2.5- 4
T-E1/ 5- 5.5
MW-12-DOE
T-E2/ .6- 2
T-E1/ 3.5- 5
T-D6/ 2- 3.5
T-C6/ 6.5- 8
T-C4/ 3.5- 5
T-SB-4/ 5- 6.5
T-SB-3/ 2.5- 4
T-SB-2/ 0- 1.5
T-B1/ 1- 2.5
Figure 2 - BaA/C vs FL/PY
Phase Equilibrium
• Total Soil Chemical Concentration
Ct = (Ms + Mw + Ma) / ρb
Ms = Cs * ρb
Mw = Cw * θw
Ma = Ca * θa *ρb
• Distribution between phases in the sample
Ct = (Cs * ρb + Cw * θw + Ca * θa) / ρb
Kd = Cs / Cw Cs = Kd * Cw
Hc = C / C C = H * C
Ms: Mass of chemical sorbed on soil solids
(ug)
Mw: Mass of chemical in pore water (ug)
Ma: Mass of chemical in soil gas (ug)
θw: Water-filled porosity (volume fraction)
θa: Air-filled porosity (volume fraction)
Pb: Dry bulk density of the soil sample (g/cm3)
Kd: Partition coefficient between pore water
and soil solids (cm3/g)
H : Dimensionless Henry's Law Constant
Page 8
Hc = Ca / Cw Cw = Hc * Ca
Ct = (Kd * Cw * ρb + Cw * θw + Cw * Hc *θa) / ρb
• Chemical concentration in pore water
Cw = Ct * ρb / (Kd * ρb + θw + Hc * θa)
• Effective solubility
Hc: Dimensionless Henry's Law Constant
Ct: Total soil chemical concentration (ug/g, dry
weight)
Cs: Chemical concentration sorbed on the soil
solids (ug/g, dry weight)
Cw: Chemical concentration in the pore water
(mg/L)
Ca: Chemical concentration in the soil gas
(mg/L)
Mass Flux and Discharge
• Four transect lines
• Data input
– Cross sectional areas (A)
– Hydraulic conductivity and gradient (k and i)
– Concentration of MTBE and TBA (C)
• Mass fluxes for each transect
– K*i*A*C (gram/day)– K*i*A*C (gram/day)
Transects 1 2 3 4
MTBE, ug/L 82 49 48 35
25,000
30,000
35,000
40,000
MTBE Concentrations
MTBE in LNAPL
0
5,000
10,000
15,000
20,000
25,000
08/12/00 12/25/01 05/09/03 09/20/04 02/02/06 06/17/07 10/29/08
MT
BE
Co
nc.
(mg
/L)
Reference (L)
MW-1
GC/FID Chromatograms
Reference (R )
MTBE and LNAPL Type
25,000
30,000
35,000
40,000M
TB
E C
on
c.
(mg
/L)
60%
70%
80%
90%
%
Correlation of MTBE and Types of LNAPL
0
5,000
10,000
15,000
20,000
08/12/00 12/25/01 05/09/03 09/20/04 02/02/06 06/17/07 10/29/08
MT
BE
Co
nc.
(mg
/L)
0%
10%
20%
30%
40%
50%
MTBE in LNAPL
L
R
D
R + D
L + R
L + D
Geochemical Parameters
• Field Parameters
– DO
– ORP
– pH
– Conductivity
• Geochemical parameters
– Nitrate, – Nitrate,
– Manganese (II),
– Fe(II)
– Sulfate
– Methane
– Chloride
– Alkalinity
Page 13
CSIA – MTBE Degradation and Potential Offsite Source
20082013
Page 14
Offsite sourceOnsite source
Summary
• Contaminant source information may be
extracted from various types of site investigation
data
• Laboratory analyses are one of the most
important datasets for source evaluation
• Concentration data may be used alone or with concentrations of other chemicals or aquifer
parameters to resolve source issues
• Data gaps identified from existing data can be
used to plan a more focused source investigation
using environmental forensics
Page 15
Questions?
Jun Lu, Ph.D.
Source A
Source B
Page 16
Jun Lu, Ph.D.AECOM EnvironmentLong Beach, CA
(562) [email protected]
