Presentation by the Army Environmental Command to the Moffett Field Restoration Advisory Board, November 20, 2014: Orion Park Housing Area Volatile Organic Compound Plume Assessment. Speaker: Matt Dayoc
EPA MEW Study Area TCE Source InvestigationSteve Williams
EPA TCE Source Investigation Findings
Middlefield-Ellis-Whisman (MEW)
Superfund Study Area
Mountain View and Moffett Field, CA
Former NAS Moffett Field
Restoration Advisory Board Meeting
February 12, 2015
Moffett RAB: EPA MEW Superfund Study Area UpdateSteve Williams
EPA Status Update
Middlefield-Ellis-Whisman (MEW) Superfund Study Area
Mountain View and Moffett Field, CA
Presentation to Former NAS Moffett Field Restoration Advisory Board
August 13, 2015
Alana Lee, EPA
Research poster - 2018 Battelle Conference on Remediation of Chlorinated Comp...Nick Jenshak
Co-Authored abstract and research poster that was accepted to the 2018 Battelle Conference on Remediation of Chlorinated and Recalcitrant Compounds under the title “Using Soil Gas Concentration Mapping to Predict Soil Vapor Extraction Radius of Influence Variances and Optimize Remedial System Design.”
EPA MEW Study Area TCE Source InvestigationSteve Williams
EPA TCE Source Investigation Findings
Middlefield-Ellis-Whisman (MEW)
Superfund Study Area
Mountain View and Moffett Field, CA
Former NAS Moffett Field
Restoration Advisory Board Meeting
February 12, 2015
Moffett RAB: EPA MEW Superfund Study Area UpdateSteve Williams
EPA Status Update
Middlefield-Ellis-Whisman (MEW) Superfund Study Area
Mountain View and Moffett Field, CA
Presentation to Former NAS Moffett Field Restoration Advisory Board
August 13, 2015
Alana Lee, EPA
Research poster - 2018 Battelle Conference on Remediation of Chlorinated Comp...Nick Jenshak
Co-Authored abstract and research poster that was accepted to the 2018 Battelle Conference on Remediation of Chlorinated and Recalcitrant Compounds under the title “Using Soil Gas Concentration Mapping to Predict Soil Vapor Extraction Radius of Influence Variances and Optimize Remedial System Design.”
Phased Sequential Soil Gas InvestigationHarryONeill
Through the use of a passive and then active soil-gas investigation, the conceptual site model (CSM) and groundwater fate and transport model were revised using these high-resolution data sets. A significant savings in project costs and compression of the project schedule was realized through implementation of this phased soil gas investigation approach, which underscores its applicability and effectiveness in mapping VOC contamination in soil.
Teresa Stephens, GIS Specialist, Paul Bechtel & Associates, Inc. and Andrew Weinberg, Geoscientist, Texas Water Development Board
Presented at the 2011 Texas GIS Forum
Integration of Seismic Inversion, Pore Pressure Prediction, and TOC Predictio...Andika Perbawa
Conventional natural gas is being exploited rapidly to achieve energy security and to satisfy the demand. However, due to the high demand for oil and gas it is becoming more difficult to find sufficient conventional reserves. To anticipate the predicted shortage of gas, we need to explore new, unconventional resources, such as shale gas. Shale gas is shale lithology that has high TOC, is brittle, and is located in the dry gas window zone. This study describes the early exploration of shale gas potential in one block in South Sumatra basin area.
In this study, the integration of geochemical data, rock physics and seismic inversion for characterizing and searching for shale gas potential will be described. The preliminary exploration stage of gas shale play covers sweet spot analysis using the Passey method to create a pseudo TOC in the target formation. Secondly, the overpressure area is mapped to avoid any potential pitfalls. Thirdly, seismic inversion is performed to map the distribution of shale based on the parameters Vp / Vs and map its TOC through conversion from Vp parameter.
As a result, log analysis shows one target zone of potential shale gas with TOC above 1% with a thickness of 100 feet. Integration of pore pressure data, shale distribution and TOC distribution of the target zone shows two potential areas in west, north-south trending, and in the east relatively of the well-X. Both locations can be recommended for the next pilot holes in order to acquire a complete set of new data and to be able to evaluate more intensively.
Seismic attributes are being used more and more often in the reservoir characterization and interpretation processes. The new software and computer’s development allows today to generate a large number of surface and volume attributes. They proved to be very useful for the facies and reservoir properties distribution in the geological models, helping to improve their quality in the areas between the wells and areas without wells. The seismic attributes can help to better understand the stratigraphic and structural features, the sedimentation processes, lithology variations, etc. By improving the static geological models, the dynamic models are also improved, helping to better understand the reservoirs’ behavior during exploitation. As a result, the estimation of the recoverable hydrocarbon volumes becomes more reliable and the development strategies will become more successful.
Removing phosphorus from drainage water the phosphorus removal structureLPE Learning Center
Full proceedings available at: http://www.extension.org/72839
We constructed a phosphorus (P) removal structure on a poultry farm in Eastern OK; this is a BMP that can remove dissolved P loading in the short term until soil legacy P concentrations decrease below levels of environmental concern. A P removal structure contains P sorbing materials (PSMs) and are placed in a location to intercept runoff or subsurface drainage with high dissolved P concentrations. As high P water flows through the PSMs, dissolved P is sorbed onto the materials by several potential mechanisms, allowing low P water to exit the structure. While they vary in form, P removal structures contain three main elements: 1) use of a filter material that has a high affinity for P, 2) containment of the material, and 3) the ability to remove that material and replace it after it becomes saturated with P and is no longer effective.
Presentation given by Dr David Jones from British Geological Survey on "Refuting leakage allegations at Weyburn" in the Storage Technical Session on Monitoring & Verification at the UKCCSRC Biannual Meeting - CCS in the Bigger Picture - held in Cambridge on 2-3 April 2014
This presentation was given as part of the EPA-funded Catchment Science and Management Course focusing on Integrated Catchment Management, held in June 2015. This course was delivered by RPS Consultants. If you have any queries or comments, or wish to use the material in this presentation, please contact catchments@epa.ie
It is increasingly being recognised internationally that integrated catchment management (ICM) is a useful organising framework for tackling the ongoing challenge of balancing sustainable use and development of our natural resource, against achieving environmental goals. The basic principles of ICM (Williams, 2012) are to:
• Take a holistic and integrated approach to the management of land, biodiversity, water and community resources at the water catchment scale;
• Involve communities in planning and managing their landscapes; and
• Find a balance between resource use and resource conservation
ICM is now well established in Australia, New Zealand, and the United States. In Europe the ICM approach has been proposed as being required to achieve effective water and catchment management, and is the approach being promoted by DEFRA for the UK, where it is called the “Catchment Based Approach” (CaBA). The principles and methodologies behind ICM sit well within the context of the Water Framework Directive with its aims and objectives for good water quality, sustainable development and public participation in water resource management. In Ireland it is proposed that the ICM approach will underlie the work and philosophy in developing and implementing future River Basin Management Plans.
Classification either on quality or type based for groundwater can offer great advantages especially in regional groundwater management. It provides a short, quick processing, interpretation for a lot of complete hydro-chemical data sets and concise presentation of the results. There is a demonstrable need for a quality assurance, with the advanced usage of world's largest fresh water storage i.e Ground water. Its getting depleted over the years and the quality of the same degrading with a rapid pace. Ground water Quality is assessed mainly by the chemical analysis of samples. The data obtained from the chemical analysis is key for the further classification, analysis, correlation etc. Graphical and Numerical interpretation of the data is the main source for Hydro-chemical studies. In this paper we test the performance of the many available graphical and statistical methodologies used to classify water samples including: Collins bar diagram, Stiff pattern diagram, Schoeller plot, Piper diagram, Durov's Double Triangular Diagram, Gibbs's Diagram, Stuyfzand Classification. This paper explains various models which classify, correlate etc., summarizing the water quality data. The basic graphs and diagrams in each category are explained by sample diagrams. In addition to the diagrams an overall characterization of hydro-chemical facies of the water can be carried out by using plots which represents a water type and hardness domain. The combination of graphical and statistical techniques provides a consistent and objective means to classify large numbers of samples while retaining the ease of classic graphical presentation.
DSD-INT 2019 ShorelineS and future coastline modelling - RoelvinkDeltares
Presentation by Dano Roelvink, IHE Delft Institute for Water Education, The Netherlands, at the Delft3D and XBeach User Day: Coastal morphodynamics, during Delft Software Days - Edition 2019. Wednesday, 13 November 2019, Delft.
A preliminary (small) study of samples at 11 producing Marcellus gas wells in Pennsylvania to determine the actual amount of radon present. The study shows that theoretical claims by anti-drillers that Marcellus Shale gas contains high, life-threatening levels of radon are simply not true.
Focusing a Mineral Spirit LNAPL Investigation Towards Remedial Design Using U...Ralph Simon, P.G.
Simon, R.T. (2017, November). Focusing a Mineral Spirit LNAPL Investigation Towards Remedial Design Using UVOST™ Combined with Traditional Sampling to Assess 3-D Distribution. Paper presented at the RE3 Conference, Philadelphia, PA.
Moffett Site 1, 22, 26, and 28 Five Year ReviewSteve Williams
Five Year Review for Installation Restoration Sites 1, 22, 26 and 28, Former Naval Air Station Moffett Field: Presentation to the Moffett Restoration Advisory Board Meeting, February 12, 2015, by Wilson Doctor, Navy Project Manager
Phased Sequential Soil Gas InvestigationHarryONeill
Through the use of a passive and then active soil-gas investigation, the conceptual site model (CSM) and groundwater fate and transport model were revised using these high-resolution data sets. A significant savings in project costs and compression of the project schedule was realized through implementation of this phased soil gas investigation approach, which underscores its applicability and effectiveness in mapping VOC contamination in soil.
Teresa Stephens, GIS Specialist, Paul Bechtel & Associates, Inc. and Andrew Weinberg, Geoscientist, Texas Water Development Board
Presented at the 2011 Texas GIS Forum
Integration of Seismic Inversion, Pore Pressure Prediction, and TOC Predictio...Andika Perbawa
Conventional natural gas is being exploited rapidly to achieve energy security and to satisfy the demand. However, due to the high demand for oil and gas it is becoming more difficult to find sufficient conventional reserves. To anticipate the predicted shortage of gas, we need to explore new, unconventional resources, such as shale gas. Shale gas is shale lithology that has high TOC, is brittle, and is located in the dry gas window zone. This study describes the early exploration of shale gas potential in one block in South Sumatra basin area.
In this study, the integration of geochemical data, rock physics and seismic inversion for characterizing and searching for shale gas potential will be described. The preliminary exploration stage of gas shale play covers sweet spot analysis using the Passey method to create a pseudo TOC in the target formation. Secondly, the overpressure area is mapped to avoid any potential pitfalls. Thirdly, seismic inversion is performed to map the distribution of shale based on the parameters Vp / Vs and map its TOC through conversion from Vp parameter.
As a result, log analysis shows one target zone of potential shale gas with TOC above 1% with a thickness of 100 feet. Integration of pore pressure data, shale distribution and TOC distribution of the target zone shows two potential areas in west, north-south trending, and in the east relatively of the well-X. Both locations can be recommended for the next pilot holes in order to acquire a complete set of new data and to be able to evaluate more intensively.
Seismic attributes are being used more and more often in the reservoir characterization and interpretation processes. The new software and computer’s development allows today to generate a large number of surface and volume attributes. They proved to be very useful for the facies and reservoir properties distribution in the geological models, helping to improve their quality in the areas between the wells and areas without wells. The seismic attributes can help to better understand the stratigraphic and structural features, the sedimentation processes, lithology variations, etc. By improving the static geological models, the dynamic models are also improved, helping to better understand the reservoirs’ behavior during exploitation. As a result, the estimation of the recoverable hydrocarbon volumes becomes more reliable and the development strategies will become more successful.
Removing phosphorus from drainage water the phosphorus removal structureLPE Learning Center
Full proceedings available at: http://www.extension.org/72839
We constructed a phosphorus (P) removal structure on a poultry farm in Eastern OK; this is a BMP that can remove dissolved P loading in the short term until soil legacy P concentrations decrease below levels of environmental concern. A P removal structure contains P sorbing materials (PSMs) and are placed in a location to intercept runoff or subsurface drainage with high dissolved P concentrations. As high P water flows through the PSMs, dissolved P is sorbed onto the materials by several potential mechanisms, allowing low P water to exit the structure. While they vary in form, P removal structures contain three main elements: 1) use of a filter material that has a high affinity for P, 2) containment of the material, and 3) the ability to remove that material and replace it after it becomes saturated with P and is no longer effective.
Presentation given by Dr David Jones from British Geological Survey on "Refuting leakage allegations at Weyburn" in the Storage Technical Session on Monitoring & Verification at the UKCCSRC Biannual Meeting - CCS in the Bigger Picture - held in Cambridge on 2-3 April 2014
This presentation was given as part of the EPA-funded Catchment Science and Management Course focusing on Integrated Catchment Management, held in June 2015. This course was delivered by RPS Consultants. If you have any queries or comments, or wish to use the material in this presentation, please contact catchments@epa.ie
It is increasingly being recognised internationally that integrated catchment management (ICM) is a useful organising framework for tackling the ongoing challenge of balancing sustainable use and development of our natural resource, against achieving environmental goals. The basic principles of ICM (Williams, 2012) are to:
• Take a holistic and integrated approach to the management of land, biodiversity, water and community resources at the water catchment scale;
• Involve communities in planning and managing their landscapes; and
• Find a balance between resource use and resource conservation
ICM is now well established in Australia, New Zealand, and the United States. In Europe the ICM approach has been proposed as being required to achieve effective water and catchment management, and is the approach being promoted by DEFRA for the UK, where it is called the “Catchment Based Approach” (CaBA). The principles and methodologies behind ICM sit well within the context of the Water Framework Directive with its aims and objectives for good water quality, sustainable development and public participation in water resource management. In Ireland it is proposed that the ICM approach will underlie the work and philosophy in developing and implementing future River Basin Management Plans.
Classification either on quality or type based for groundwater can offer great advantages especially in regional groundwater management. It provides a short, quick processing, interpretation for a lot of complete hydro-chemical data sets and concise presentation of the results. There is a demonstrable need for a quality assurance, with the advanced usage of world's largest fresh water storage i.e Ground water. Its getting depleted over the years and the quality of the same degrading with a rapid pace. Ground water Quality is assessed mainly by the chemical analysis of samples. The data obtained from the chemical analysis is key for the further classification, analysis, correlation etc. Graphical and Numerical interpretation of the data is the main source for Hydro-chemical studies. In this paper we test the performance of the many available graphical and statistical methodologies used to classify water samples including: Collins bar diagram, Stiff pattern diagram, Schoeller plot, Piper diagram, Durov's Double Triangular Diagram, Gibbs's Diagram, Stuyfzand Classification. This paper explains various models which classify, correlate etc., summarizing the water quality data. The basic graphs and diagrams in each category are explained by sample diagrams. In addition to the diagrams an overall characterization of hydro-chemical facies of the water can be carried out by using plots which represents a water type and hardness domain. The combination of graphical and statistical techniques provides a consistent and objective means to classify large numbers of samples while retaining the ease of classic graphical presentation.
DSD-INT 2019 ShorelineS and future coastline modelling - RoelvinkDeltares
Presentation by Dano Roelvink, IHE Delft Institute for Water Education, The Netherlands, at the Delft3D and XBeach User Day: Coastal morphodynamics, during Delft Software Days - Edition 2019. Wednesday, 13 November 2019, Delft.
A preliminary (small) study of samples at 11 producing Marcellus gas wells in Pennsylvania to determine the actual amount of radon present. The study shows that theoretical claims by anti-drillers that Marcellus Shale gas contains high, life-threatening levels of radon are simply not true.
Focusing a Mineral Spirit LNAPL Investigation Towards Remedial Design Using U...Ralph Simon, P.G.
Simon, R.T. (2017, November). Focusing a Mineral Spirit LNAPL Investigation Towards Remedial Design Using UVOST™ Combined with Traditional Sampling to Assess 3-D Distribution. Paper presented at the RE3 Conference, Philadelphia, PA.
Moffett Site 1, 22, 26, and 28 Five Year ReviewSteve Williams
Five Year Review for Installation Restoration Sites 1, 22, 26 and 28, Former Naval Air Station Moffett Field: Presentation to the Moffett Restoration Advisory Board Meeting, February 12, 2015, by Wilson Doctor, Navy Project Manager
Moffett RAB: EPA Update on Environmental Issues Management PlanSteve Williams
Update on Environmental Issues Management Plan (EIMP)
Presentation to the Former NAS Moffett Field RAB Meeting
August 13, 2015
By Alana Lee, EPA
Elizabeth Wells, Water Board
High Resolution Site Characterization (#HRSC) of Gasoline LNAPL Plume Migrati...John Fontana
A gasoline release resulted in a LNAPL plume that had migrated several hundred feet south of the site, opposite of groundwater gradient A HRSC survey using OIP-UV and MiHPT tools were used to map out the hydrostratigraphy, confined LNAPL and dissolved phase plume. The high resolution data was put into a 3D visualization model that helped explain the unusual migration patters that were the result of LNAPL confining conditions.
Preliminary Technical Evaluation of Three Reports by U.S. Environmental Prote...LPE Learning Center
http://www.extension.org/72802 The Yakima Valley is a large agricultural area where there are multiple potential sources of nitrate in groundwater. Potential sources are intermingled, i.e., homes with septic systems are on the same properties as the dairies or adjacent to farms and/or dairies. In 2012, Region 10 of the US Environmental Protection Agency undertook a study to source track and identify nitrogen sources in the Yakima River Basin as part of an enforcement effort focusing on dairies. EPA position was that the targeted dairies did not properly apply nutrients to land application fields at agronomic rates, resulting in groundwater contamination. The study area is underlain by 3 aquifers, a shallow perched aquifer likely related to irrigation return flows, an alluvial aquifer and an underlying basalt aquifer. The three aquifers are hydrologically connected either through natural pathways or through wells completed into more than one aquifer. Because none of the potential sources are isolated, source tracking requires an in-depth knowledge of aquifer properties such as aquifer thickness, groundwater flow direction, hydraulic conductivity, and vertical leakance in addition to understanding localized effects of ditches, drains and production wells on groundwater flow. EPA focused on groundwater chemistry, assuming that indicators such as pesticides and other trace organic compounds would tie the groundwater nitrate to a specific source. EPA’s study failed to yield clear indicators pointing to specific sources and did not collect hydrologic data for its 2012 report to gain a detailed understanding of aquifer properties. This presentation will address how to accurately characterize the hydrogeology below dairy production areas and land application fields, and how to proactively manage nutrients to protect dairies from unsubstantiated enforcement actions.
The Susquehanna River Basin Commission (SRBC) launched a state-of-the-art Remote Water Quality Monitoring Network in 2010 to track water quality throughout the SRBC region. Of concern is whether or not Marcellus drilling in the Susquehanna River Basin has affected water quality. The SRBC has issued this second, comprehensive report on their findings thus far. The SRBC has found that Marcellus Shale drilling is not/has not adversely affected water quality anywhere in the region.
A field study assessing the impact of on site valerie mc-carthy_slideshareValerie McCarthy
A field study assessing the impact of on-site wastewater treatment systems on surface water quality in a Co. Monaghan catchment at the INTERNATIONAL SYMPOSIUM ON DOMESTIC WASTEWATER TREATMENT & DISPOSAL SYSTEMS TRINITY COLLEGE, DUBLIN, IRELAND Monday 10th & Tuesday 11th September, 2012
Dan Wrye, Pierce County Water Quality Manager, presented the results of the 2014 Watershed Health Report Card, including the health of the Nisqually Watershed. He presented at the October 2015 NRC meeting
Presentation given by Joe Harrington, Cork Institute of Technology,at the workshop on Sediment Fluxes in Irish Rivers (Siltflux Workshop) = 28/10/14, UCD, Dublin 4
EPA MEW Sampling Update, Moffett RAB, November 14, 2013Steve Williams
EPA update to the Moffett Restoration Advisory Board November 14, 2013, describing the investigation of TCE hotspots near Evandale Avenue, Leong Drive, and the Gateway Property (former County Vector Control Yard) adjacent to the MEW Superfund site in Mountain View, CA.
Co-Chair NASA/GSA Presentation to Moffett RAB May 10, 2012
Orion Park Housing Area VOC Plume Assessment
1. Army Environmental Command
Moffett Field
Restoration Advisory Board
Orion Park Housing Area
November 20, 2014
Matt Dayoc / clayton.m.dayoc.civ@mail.mil / 210-466-1892 1 of 5 20 November 2014
2. Previous Investigations
Investigation Title Year Investigator Report Conclusions
Soil and Groundwater
Investigation
1999 NASA VOCs detected in groundwater beneath
downgradient boundary
Groundwater
Investigation
2000 Navy VOCs detected in groundwater beneath
upgradient and downgradient boundaries
Site Characterization 2002 Navy No on-site sources identified
Off-Site Investigation 2003 Army Detected VOCs in groundwater from
upgradient monitoring points
Off-Site Investigation 2005 EPA Detected VOCs in upgradient off-site
monitoring points
Groundwater
Investigation/Monitoring
Well Installation
2005 Navy Groundwater hot spots identified beneath
OPHA, but no on-site sources identified
Septic Tank and Drain
Field Investigation
2009 Army Septic tank and drain field not a source
Supplemental Site
Investigation
2012 Army Groundwater hot spots identified beneath
OPHA, but no on-site sources identified
Off-Site Investigations 2013-
Matt Dayoc / clayton.m.dayoc.civ@mail.mil / 210-466-1892 2 of 5 20 November 2014
2014
EPA Upgradient hot spots similar to those under
OPHA identified, sources unclear
3. Supplemental Site Investigation
• Overview:
• Voluntary investigation by Army
• Work Plan approved by agencies
• Purpose - Investigate locations of concern (LOCs)
previously identified with input from EPA and Water
Board
• Approach:
• Verified previous groundwater data (flow direction/VOC
concentrations)
• Investigated LOCs
• 35 borings collected from the areas requested by regulators
using cone penetrometer test with membrane interface probe
• 9 direct push technology borings (11 GW samples, 1 soil
sample)
Matt Dayoc / clayton.m.dayoc.civ@mail.mil / 210-466-1892 3 of 5 20 November 2014
4. Supplemental Site Investigation
• Conclusions
– No on-site sources
– TCE plume underflows OPHA from southern boundary
• Due Diligence
– The Army requested Oak Ridge National Laboratories to conduct
an evaluation of data collected by both DoD and EPA.
– Purpose:
• Perform an independent third-party review of the conclusions
reached from the multiple historical assessments at and
around OPHA
• Conduct, if necessary, further evaluation of existing data to
verify those conclusions
Matt Dayoc / clayton.m.dayoc.civ@mail.mil / 210-466-1892 4 of 5 20 November 2014
5. Assessment of
Plumes Beneath
OPHA Site
David Watson
Jennifer Earles, Abigail Maloof,
Robert Bock, Anthony
Armstrong & Patti Reno
Oak Ridge National Laboratory
ORNL is managed by UT-Battelle
for the US Department of Energy
for
US Army Environmental
Command
6. Objective
• Conduct holistic assessment of plumes migrating
beneath OPHA property:
– Environmental setting
– Plume composition and extents
– Transport pathways
– Potential source areas
6 OPHA Assessment - 11/20/14 RAB Meeting
7. Data sources
• Multiple consultants reports reviewed
– Supplemental Site Investigation Report, 2012; Groundwater
Monitoring Well Installation And Sampling Report For Orion
Park Housing Area, 2007 and other historical OPHA site
investigations
– MEW and other site reports
• RWQCB online site database
• RAB documents
• Electronic data provided by EPA
• No new field studies
7 OPHA Assessment - 11/20/14 RAB Meeting
8. Approach & Methods
• Well data used to conduct fingerprint analysis
– Dot size represents total conc.
during sampling event
– Pie shows % TCE and cis-12-DCE
– Concentration/signatures used to
identify sources and pathways
• Transport pathways assessed
– Groundwater from storm drain releases at Leong Dr. site up
gradient of OPHA
– Sanitary sewer flowing past OPHA on east side
– Storm drain discharges to creek and infiltration to
groundwater on west side of OPHA
• Variability assessment (variability creates “hot spots”)
– Vertically and horizontally (stratigraphy and contaminants)
8 OPHA – Assessment Over - time 11/20/14 RAB (time Meeting
series plots)
Linear scale
Log scale with
adjustments
used to show
whole range
9. Multiple regional plumes and source areas
9 OPHA Assessment - 11/20/14 RAB Meeting
Groundwater
flow direction
10. Potential Local Sources
TCE concentrations
A2/B1 zones (45-65 Ft Bgs)
10 OPHA Assessment - 11/20/14 RAB Meeting
Groundwater
flow direction
Groundwater
flow direction
Leong Dr. Site
11. VOC distribution in wells (all zones)
Linear scaling showing major regional sources
Groundwater
flow direction
Leong Dr.
Site MEW
11 OPHA Assessment - 11/20/14 RAB Meeting
Sites
Major
sources with
DNAPL likely
present
OPHA
N
12. VOC distribution in wells (all zones)
Patterns in VOC distribution provide indication of sources
Groundwater
flow direction
Leong Dr.
Site MEW
N
12 OPHA Assessment - 11/20/14 RAB Meeting
A
C
B
A) DCE & TCE
mixed plume
from storm
drain leak at
Leong Dr.
B) TCE plume
from sanitary
sewer
C) DCE & TCE
mixed plume
from Stevens
Creek and A &
B contributions
Log scale
- TCE along drains from MEW sites
- Significant degradation to cis-12-DCE in Leong Dr. subsurface
13. VOC distribution in A1 wells (<29’)
Shallow zones much greater percent cis-12-DCE
13 OPHA Assessment - 11/20/14 RAB Meeting
A
C
B
A) DCE & TCE
mixed plume
from storm
drain leak at
Leong Dr.
B) TCE plume
from sanitary
sewer
C) DCE & TCE
mixed plume
from Stevens
Creek and A &
B contributions
Log scale
Groundwater
flow direction
Leong Dr.
Site MEW
N
14. VOC distribution in A2 wells (29-50’)
Increasing amounts of TCE
Log scale A) DCE & TCE
Groundwater
flow direction
14 OPHA Assessment - 11/20/14 RAB Meeting
A
C
B
mixed plume
from storm
drain leak at
Leong Dr.
B) TCE plume
from sanitary
sewer
C) DCE & TCE
mixed plume
from Stevens
Creek and A &
B contributions
Leong Dr.
Site MEW
15. VOC distribution in B1 wells (50-70’)
TCE more dominant
Log scale
Groundwater
flow direction
15 OPHA Assessment - 11/20/14 RAB Meeting
Limited information
on extent at
greater depths but
TCE is dominant
Leong Dr.
Site
MEW
N
16. Subsurface drainage system
Sanitary sewer connection to OPHA
Leong Dr.
Site
16 OPHA Assessment - 11/20/14 RAB Meeting
MEW
17. Leong Dr.
Site
17 OPHA Assessment - 11/20/14 RAB Meeting
Sanitary Sewer system
Flow from MEW is past OPHA
site not across Stevens Creek
OPHA
Primary flow
Direction
From MEW
Overflow only
Adapted from EPA 8/11/2104
presentation at MEW/Moffett Field
Community Advisory Board
Meeting
18. “Source 2” cluster from Cl isotope analysis
related to sanitary sewer TCE plume?
Cluster 2
MCH-5UA
87B1
Cluster 2
MCH-5UA
87B1
18 OPHA Assessment - 11/20/14 RAB Meeting
OPHA
N
19. Storm Drain contaminant discharge to Stevens Creek
Storm Drain
OPHA Site
Stevens Creek
19 OPHA Assessment - 11/20/14 RAB Meeting
OPHA
Stevens Creek
Stevens Creek
Sanitary Sewer
Groundwater
flow direction
N
20. Storm Drain contaminant discharge to Stevens Creek
• Chemical release from storm sewer in 1978 extended 0.5
miles downstream resulted in fish kills
• No flow in the Stevens Creek at the time
• Infiltration from the Creek is a likely source of GW
contamination at OPHA site from this and other spills
Log scale
20 OPHA Assessment - 11/20/14 RAB Meeting
Periods of
no flow
Reach of
Creek
Impacted
during spill
Groundwater
flow direction
Leong Dr.
Site MEW
N
21. Stratigraphic control of plume distribution
Upper A zone Lower A top zone Lower A bottom zone
21 OPHA Assessment - 11/20/14 RAB Meeting
Distribution of
coarse sand
and gravel
controls VOC
distribution
22. Stratigraphic control of plume distribution
Upper A zone Lower A top zone Lower A bottom zone
22 OPHA Assessment - 11/20/14 RAB Meeting
Distribution of
coarse sand
and gravel
controls VOC
distribution
Stratigraphy and plume
signatures correlate
27. Leong Dr. TCE & Stratigraphy
X-section parallel to drains/perpendicular to flow
5-100 ppb
100-1000
1000-10000
>10000
Adapted from:
>5
- Variable VOC concentrations laterally and with depth
- Vertical extent not defined
28. Leong Dr. TCE & Stratigraphy
Parallel to GW flow direction
Adapted from:
>5
Storm drain &
Sanitary sewer
Flow direction
- Variable VOC concentrations laterally and with depth
- Vertical extent not defined
29. Spatial variability in VOC concentrations
is expected in fluvial environments
N
29 OPHA Assessment - 11/20/14 RAB Meeting
A
A’
B’
B
Groundwater
flow direction
30. Variability in Total VOC concentrations
Section A-A’ All zones
Groundwater
flow direction
A’ A’
Groundwater
flow direction
A A
30 OPHA Assessment - 11/20/14 RAB Meeting
OPHA Site
OPHA Site
Leong
Rd Site
Leong
Rd Site
Linear scale Log scale
Groundwater
flow direction
31. Variability in total VOC concentrations
Section A-A’
A A’ A
31 OPHA Assessment - 11/20/14 RAB Meeting
Leong
Rd Site
OPHA Site OPHA Site
Leong
Rd Site
A1 Zone A2/B1 Zone
A’
Groundwater
flow direction
Groundwater
flow direction
Groundwater
flow direction
32. Variability in Total VOC concentrations
Section B-B’ All zones
Groundwater
flow direction
B Groundwater
flow direction
B’ B B’ OPHA Site
32 OPHA Assessment - 11/20/14 RAB Meeting
OPHA Site
NASA
Creek Creek
Linear scale Log scale
NASA
Groundwater
flow direction
33. Variability in total VOC concentrations
Section B-B’
Groundwater
flow direction
B Groundwater B’ B B’
flow direction
NASA
OPHA Site OPHA Site
33 OPHA Assessment - 11/20/14 RAB Meeting
Creek
Creek
NASA
A1 Zone A2/B1 Zone
Groundwater
flow direction
34. VOC concentrations vary over time
Total VOCs (ppb)
34 OPHA Assessment - 11/20/14 RAB Meeting
Groundwater
flow direction
35. VOC concentrations over time (A1 Zone)
Individual VOCs (ppb)
TCE cis-1,2-DCE
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Dechlorination
pathway
More degradation at
shallow depths
Note: Inverse
relationship between
cis-1,2-DCE and VC for
upgradient well W89-6
Vinyl chloride
trans-1,2-DCE 1,1-DCE
36. VOC concentrations over time (A2 Zone)
Individual VOCs (ppb)
TCE
36 OPHA Assessment - 11/20/14 RAB Meeting
Dechlorination
pathway
Secondary Y axis, is for
MCH-2LA
Less degradation
at depth
cis-1,2-DCE
Vinyl chloride
trans-1,2-DCE
1,1-DCE
37. OPHA soil sampling data
Only low levels detected onsite - not indicative of a source
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Farm
Septic Tank
SOILS
Total VOCs
(ug/kg)
Paint locker
Groundwater
flow direction
38. Conclusions
• Plumes are a mixture of TCE and cis-1,2-DCE
– Misinterpretation could result if only consider TCE
• Onsite plume distribution and variability (“hot spots”)
related to stratigraphic and spatial heterogeneity
(preferred pathways) and variable release history from
source areas that are offsite
• There is very little to no evidence that the plumes
beneath the OPHA site are the result of onsite
contaminant releases
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39. Conclusions
• Three potential sources/pathways for major quantities
of VOCs (TCE & cis-1,2-DCE) to migrate on to OPHA
site were identified
– Groundwater transport from storm drain releases at Leong
Dr. site up gradient of OPHA (shallow cis-1,2-DCE signature
with greater fraction TCE deeper)
– VOC leaks from the sanitary sewer flowing past OPHA on
east side (TCE dominant)
– Storm drain discharges to Stevens creek and subsequent
infiltration to groundwater on the west side of OPHA
(shallow cis-1,2-DCE signature with greater fraction TCE
deeper)
39 OPHA Assessment - 11/20/14 RAB Meeting