Evaluating Risk of Heritage LNAPL Bodies. International Petroleum Environmental Conference 10/14/14

Evaluating Risk of Heritage LNAPL Bodies International Petroleum Environmental Conference 10/14/14

Evaluating Risk Source ITRC after Huntley and Beckett 2002

What is a Heritage LNAPL Body One or many of the following: Significantly aged LNAPL body Inherited LNAPL site with no prior remediation Prior remediation but no source reduction data

Remediation History 3 Vacuum Wellpoint Systems No LNAPL Recovery Data Total Flow, but Not from Individual Pumping Wells

Evaluating Risk Vapor Direct Contact LNAPL Migration Dissolved Phase

Vapor Torkelson Geochemistry, Inc. Stieglitz Park ITF, Whiting Refinery Sample ID : 145A Acquired : May 30, 2012 13:43:24 c :\ez chrom\chrom \12099\145a -- C hannel A Weathered diesel range fuel, small concentrations of finished gasoline product Page 1 of 1 (1) 50 50 M i l l i v o l t s 25 nc4 i C5 nc5 2M Pentane ol efi nc6 n a c b 2, 4 DMP B nz Isooct ane nc7 MCHX T ol nc8 EB m/p-xyl nc9 1, 2,4 T MB nc10 nc11 Naph IP 13 IP 15 IP 16 nc14 nc12 IP 14 nc13 P ri st ane nc15 nc16 IP 18 0 0 0 5 10 15 20 25 30 35 40 M inutes nc17 nc18 P hytane nc19 nc20 nc21 nc22 nc23 nc24 nc25 nc26 nc27 nc28 nc29 nc30 nc32 nc33 nc35 nc36 nc38 nc40 25 M i l l i v o l t s

Evaluating Risk Vapor Direct Contact LNAPL Migration Dissolved Phase

8/20/1998 8/20/1999 8/20/2000 8/20/2001 8/20/2002 8/20/2003 8/20/2004 8/20/2005 8/20/2006 8/20/2007 8/20/2008 8/20/2009 8/20/2010 8/20/2011 8/20/2012 8/20/2013 8/20/2014 Elevation (MSL) Direct Contact ANI NWI CGWS GS TOS BOS 587 583 579 575 571 567

Evaluating Risk Vapor Direct Contact LNAPL Migration Dissolved Phase

LNAPL Migration

LNAPL Migration New Monitoring Wells Geologic Classification and TPH Grab Sampling Undisturbed Cores and Discrete Interval TPH Subsampling

Depth LNAPL Migration LNAPL Saturation 0 0 0.05 0.1 0.15 0.2 0.25 2 4 6 Water Table 8 10 12 14

Depth LNAPL Migration LNAPL Saturation 0 0 0.05 0.1 0.15 0.2 0.25 Water Table 2 4 Fine to Medium (SW) 6 8 Poorly Graded Sand, fine to medium (SP) 10 Well Graded Sand with Gravel, medium to coarse (SW) 12 14 Well Graded Sand, fine to medium, trace gravel (SW)

Depth LNAPL Migration LNAPL Saturation 0 0 0.05 0.1 0.15 0.2 0.25 Sn Grab 2 Water Table 4 6 Fine to Medium (SW) 8 Poorly Graded Sand, fine to medium (SP) 10 12 14 Well Graded Sand with Gravel, medium to coarse (SW) Well Graded Sand, fine to medium, trace gravel (SW)

Depth LNAPL Migration 0 LNAPL Saturation 0 0.05 0.1 0.15 0.2 0.25 Sn Grab 2 Water Table 4 Screen Length 6 Fine to Medium (SW) 8 10 12 14 Poorly Graded Sand, fine to medium (SP) Well Graded Sand with Gravel, medium to coarse (SW) Well Graded Sand, fine to medium, trace gravel (SW)

LNAPL Migration Undisturbed Cores Sampled for Pore Fluid Saturation Data and Capillary Pressure Saturation Curves PFS PFS TPH O/W Pc PFS PFS TPH O/W Pc PFS PFS PFS

Depth LNAPL Migration 0 LNAPL Saturation 0 0.05 0.1 0.15 0.2 0.25 Sn Grab Sn Core 2 Water Table 4 Screen Length 6 8 10 12 14 Fine to Medium (SW) Poorly Graded Sand, fine to medium (SP) Well Graded Sand with Gravel, medium to coarse (SW) Well Graded Sand, fine to medium, trace gravel (SW)

Depth LNAPL Migration 0 LNAPL Saturation 0 0.05 0.1 0.15 0.2 0.25 Sn Grab Sn Core 2 Sn API RP 40 4 Water Table 6 Screen Length 8 Fine to Medium (SW) 10 12 14 Poorly Graded Sand, fine to medium (SP) Well Graded Sand with Gravel, medium to coarse (SW) Well Graded Sand, fine to medium, trace gravel (SW)

LNAPL Migration Monitoring Wells with Mobile LNAPL T n Tests Completed (Manual Skim or Baildown)

Depth (ft) ANT (ft) LNAPL Migration Baildown Test 5.0 DTW (blue), Water Table (purple), DTP (red), ANT (green) 6 6.0 5 7.0 4 8.0 9.0 3 10.0 2 11.0 1 12.0 0 6/16/14 0:00 6/17/14 0:00 6/18/14 0:00 6/19/14 0:00 6/20/14 0:00 6/21/14 0:00 6/22/14 0:00 6/23/14 0:00 Time (minutes)

Normalized Drawdown (s/s initial ) (ft/ft) LNAPL Migration 1.0 API LNAPL Transmissivity Workbook Calculation of LNAPL Transmissivity from Baildown Test Data 0.9 STEP 1: RESET OUTPUT SUMMARY 0.8 0.7 RESET STEP 4: LNAPL TRANSMISSIVITY SUMMARY Output Summary T=0.03125 ft2/day 0.6 0.5 STEP 2: ENTER DATA & VIEW FIGURES STEP 3: CHOOSE WELL CONDITIONS Mean LNAPL Transmissivity (ft 2 /d) 0.25 T=0.0625 ft2/day 0.4 0.3 0.2 0.1 0.0 Unconfined Confined T=0.125 ft2/day T=0.25 ft2/day Perched T=0.5 ft2/day T=2 ft2/day T=1 ft2/day 0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000 Time (min) Standard Deviation (ft 2 /d) 0.08 Coefficient of Variation 0.30

Depth LNAPL Migration 0 2 LNAPL Saturation 0 0.05 0.1 0.15 0.2 0.25 Sn Grab Sn Core Sn API RP 40 Water Table 4 Residual Sn 6 Screen Length 8 Fine to Medium (SW) 10 12 14 Poorly Graded Sand, fine to medium (SP) Well Graded Sand with Gravel, medium to coarse (SW) Well Graded Sand, fine to medium, trace gravel (SW)

Evaluating Risk Vapor Direct Contact LNAPL Migration Dissolved Phase

Dissolved Phase 809 803A 804 806 Chemical Name Screening Level 10/14/1991 9/23/1991 9/23/2013 10/3/2013 9/26/2013 9/24/1991 10/30/2013 (µg/l) Benzene 5 0.24 1100 57 U J 0.50 U Methylene Chloride 5 5.0 122 U J 5.0 U 1-Methylnaphthalene 9.7 5.0 10 13 U 0.95 0.96 1.2 U Bis(2-ethylhexyl) phthalate 6 50 100 13 28 B U 9.5 9.6 12 U Naphthalene 1.4 5.0 10 12 14 J U 0.95 0.96 1.2 U

Dissolved Phase Dissolved phase sampling: September and October 2014

Dissolved Phase Full Dissolved Phase Plume Analysis: 2013/2014

Next Steps Evaluate recent dissolved phase data Modeling dissolved phase contaminant transport without system pumping Evaluate natural attenuation using CO 2 flux study, temperature profile study and evaluation of bioavailable electron acceptors

Preliminary Conclusions Vapor risk minimal Direct contact risk must be addressed by future remedy at isolated areas of high water table LNAPL mobility testing showed localized areas of potentially recoverable volumes but minimal risk reduction by LNAPL recovery Dissolved phase data suggests low risk but data gaps must be filled

Evaluating Risk Unknown Low Risk Approaching Residual Source ITRC after Huntley and Beckett 2002

Thank You Questions Colin McLeod colin.mcleod@urs.com