Considerations for Applying 

the Triad Approach 

Hartford Area Hydrocarbon Plume Site 

Hartford, Illinois 
Considerations for Applying the Triad Approach 

Hartford Area Hydrocarbon Plume Site 

Hartford, Illinois

Prepared by 

U.S. Environmental Protection Agency 

Office of Superfund Remediation and Technology Innovation 

Superfund Triad Support Team 

In cooperation with: 

U.S. Environmental Protection Agency Region V 

EPA 542-R-06-008 

August 2007 

www.epa.gov 

clu-in.org 

United States 

Environmental Protection 

Agency 

Office of Solid Waste and 

Emergency Response 

(5102G) 
i 

Notice 

This report was funded U.S. Environmental Protection Agency (EPA) Office of Superfund Remediation 

and Technology Innovation (OSRTI) under Contract Number 68-W-02-034. Mention of trade names or 

commercial products does not constitute endorsement or recommendation for use. 

A limited number of copies of this report are available free of charge from the National Service Center for 

Environmental Publications (NSCEP). Refer to document number EPA 542-R-06-008 when ordering. 

Order via the Web site, by mail, or by facsimile from: 

EPA/ National Service Center for Environmental Publications 

P.O. Box 42419 

Cincinnati, OH 45242-2419; 

Telephone (800) 490-9198 

Fax: (301) 604-3408 

This document can also be obtained electronically through EPA's Clean Up Information (CLU-IN) 

System on the World Wide Web at http://cluin.org. 

Comments or questions about this report may be directed to Stephen Dyment, EPA, OSRTI (5203P), 

1200 Pennsylvania Avenue NW, Washington, D.C. 20460; telephone: (703) 603-9903; e-mail: 

dyment.stephen@epa.gov. 
ii 

Foreword 

This document is one in a series designed to provide information about innovative technologies and 

approaches that support less costly and more representative site characterization. These documents 

include reports about new technologies as well as novel applications of familiar tools or processes. They 

are prepared to offer operational experience and to communicate information about ways to improve the 

efficiency of data collection at hazardous waste sites. 

Acknowledgments 

Special acknowledgement is given to EPA Region 5, other federal and state staff and remediation 

professionals, and to the staff of Tetra Tech EM Inc. for their support in preparing this document. 
iii 

CONTENTS 

Section Page

ACRONYMS AND ABBREVIATIONS.....................................................................................................vi

1.0 INTRODUCTION............................................................................................................................1

1.1 THE TRIAD APPROACH..................................................................................................1

1.2 BACKGROUND.................................................................................................................2

1.3 PROJECT OBJECTIVES ...................................................................................................3

1.4 PRINCIPAL STUDY QUESTIONS...................................................................................3

2.0 PRELIMINARY CONCEPTUAL SITE MODEL...........................................................................5

2.1 CURRENTLY IDENTIFIED REGIONAL DATA GAPS .................................................6

2.2 GENERAL SUGGESTIONS FOR FILLING REGIONAL DATA GAPS ........................6

2.3 GEOLOGY, HYDROGEOLOGY, AND CONTAMINANT DISTRIBUTIONS..............7

2.3.1 ROST Results, Contaminant Transport, and Source Areas....................................8

2.3.1.1 ROST Results and Product Recovery Challenges .................................8

2.3.2 Sand and Clay Isopach, Formation Top, and Free Product Thickness Maps.........9

2.3.2.1 North Olive Sand Maps .......................................................................10

2.3.2.2 Rand Stratum Maps..............................................................................11

2.3.2.3 EPA Stratum Maps ..............................................................................11

2.3.2.4 Main Sand Maps ..................................................................................12

2.3.2.5 Light Range Petroleum Hydrocarbon Maps ........................................12

2.3.2.6 Mid-Range Petroleum Hydrocarbon Maps..........................................13

2.3.2.7 Heavy Range Petroleum Hydrocarbon Maps.......................................13

2.3.2.8 Total Petroleum Hydrocarbon Map .....................................................13

2.3.3 Interaction of Shallow Stratums with Sewers and Utilities..................................14

2.4 HYDROCARBON CHEMISTRY AND GEOCHEMISTRY ..........................................14

3.0 SUGGESTIONS FOR OPTIMIZING CLEANUP SYSTEM DESIGN AND 

IMPLEMENTATION ....................................................................................................................17

3.1 SOIL VAPOR EXTRACTION SYSTEM DESIGN AND OPTIMIZATION .................18

3.1.1 Traditional Vadose Zone Profiling and Monitoring Techniques .........................18

3.1.2 Soil Sampling.......................................................................................................19

3.1.3 Soil Permeability Testing.....................................................................................20

3.1.4 Vapor Monitoring Points......................................................................................21

3.1.5 SVE Pilot Testing.................................................................................................21

3.2 PNEUMATIC WELL LOGGING TECHNOLOGY ........................................................22

3.2.1 Equipment ............................................................................................................22

3.2.2 Permeability Profiles............................................................................................23

3.2.3 Concentration Profiles..........................................................................................25

3.3 OPTIMIZING AN SVE SYSTEM AND IDENTIFYING SVE AS A VIABLE 

REMEDIAL ALTERNATIVE..........................................................................................26

3.3.1 Technology Assessment.......................................................................................27

3.3.2 Monitoring the Effectiveness of a Cleanup Strategy............................................28

3.4 GEOVIS VIDEO MICROPSCOPE ESTIMATES OF IN SITU NAPL SATURATIONS 

USING CPT TECHNOLOGY..........................................................................................28

3.4.1 Equipment ............................................................................................................29

3.4.2 Effective Porosity.................................................................................................30

3.4.3 NAPL Saturation..................................................................................................31

3.5 ADDITIONAL SITE CHARACTERIZATION ACTIVITIES ........................................32

4.0 INCORPORATING TRIAD-DRIVEN DYNAMIC WORK STRATEGIES................................34

4.1 SUMMARY OF SUGGESTIONS....................................................................................35

4.2 SUMMARY ......................................................................................................................37

5.0 REFERENCES...............................................................................................................................38 
iv 

LIST OF FIGURES 

Figure

1 LOCATION MAP 

2 REGIONAL GEOLOGIC CROSS SECTION 

3 GEOLOGIC CROSS SECTION SHOWING FORMATION DISTRIBUTION IN AND 

SURROUNDING THE HARTFORD AREA HYDROCARBON PLUME SITE 

4 PRELIMINARY GEOLOGICAL CONCEPTUAL SITE MODEL 

5 ROST APPROXIMATE EXTENT OF HYDROCARBON MAP 

6 AVULSION OF A SEDIMENTARY SEQUENCE 

7 CROSS SECTION OF A MIXED LOAD RIVER 

8 ISOPACH OF A-CLAY ABOVE STRATUMS INDICATED 

9 NORTH OLIVE STRATUM ISOPACH 

10 TOP OF RAND AND MAIN STRATUM 

11 THICKNESS OF RAND STRATUM IN FEET 

12 ISOPACH OF SILTY CLAY BETWEEN RAND STRATUM OR MAIN SAND AND THE 

NORTH OLIVE STRATUM OR GROUND SURFACE 

13 TOP OF EPA STRATUM 

14 EPA STRATUM ISOPACH 

15 ISOPACH OF SILTY CLAY BETWEEN EPA STRATUM OR MAIN SAND AND THE 

RAND STRATUM OR NORTH OLIVE STRATUM 

16 TOP OF MAIN SAND 

17 TOP OF TOTAL PETROLEUM HYDROCARBON ROST RESPONSE 

18 TOTAL PETROLEUM HYDROCARBON ROST RESPONSE THICKNESS 

19 LOCATIONS WHERE POROUS STRATUM (SAND UNITS) ARE POTENTIALLY IN 

CONTACT WITH PRODUCT PIPELINES AND MUNICIPAL SEWERS 
v 

LIST OF EXHIBITS 

Exhibit

1 SCHEMATIC OF PNEUMATIC WELL LOGGING EQUIPMENT 

2 EXAMPLE PNEUMATIC WELL LOGGING RESULTS FOR SOIL PERMEABILITY TO AIR 

3 SAMPLE OF PNEUMATIC WELL LOGGING RESULTS FOR CONTAMINANT PRODUCT 

4 SCHEMATIC OF GeoVIS DIRECT-PUSH PROBE 

5 ESTIMATED SOIL POROSITY (VADOSE ZONE) FROM GeoVIS IMAGES 

6 VERTICAL PROFILE OF SOIL PHOTOMICROGRAPHS WITH DNAPL DROPLETS 
vi 

ACRONYMS AND ABBREVIATIONS 

AOC Administrative Order on Consent 

bgs Below ground surface 

CCD Charged-coupled device 

Clayton Clayton Group Services 

CPT Cone penetrometer test 

CSM Conceptual site model 

DNAPL Dense nonaqueous phase liquid 

EPA U.S. Environmental Protection Agency 

Hartford site Hartford Area Hydrocarbon Plume 

HSA Hollow stem auger (HSA) 

HS Heavy sheen 

HWG Hartford Working Group 

IEPA Illinois Environmental Protection Agency 

ITRC Interstate Technology Regulatory Council 

LED Light-emitting diode 

LIF Laser induced fluorescence 

mg/m3

 Milligrams per cubic meter 

MIP Membrane interface probe 

MS Moderate sheen 

NAPL Nonaqueous phase liquid 

NS No sheen 

OSC On-scene coordinator 

OSRTI Office of Superfund Remediation and Technology Innovation 

PAH Polynuclear aromatic hydrocarbons 

PID Photoionization detector 

Praxis Praxis Environmental Technologies, Inc. 

RCRA Resource Conservation and Recovery Act 

ROI Radius of influence 

ROST Rapid Optical Screening Tool 

scfm Standard cubic feet per minute 

SS Slight sheen 

START Superfund Technical Assessment and Response Team 

SVE Soil vapor extraction 

TCE Trichloroethylene 

Tetra Tech Tetra Tech EM Inc. 
vii 

UVF Ultraviolet fluorescence 

VMP Vapor monitoring points 

VOC Volatile organic compound 
1

1.0 INTRODUCTION 

Tetra Tech EM Inc. (Tetra Tech) prepared the following work products and related suggestions on 

integration of the principles of the Triad approach at the Hartford Area Hydrocarbon Plume (the Hartford 

site) in Hartford, Illinois. Tetra Tech prepared this document through its support to the U.S. 

Environmental Protection Agency (EPA) Office of Superfund Remediation and Technology Innovation 

(OSRTI), and in cooperation with the Superfund Technical Assessment and Response Team (START) 

and EPA Region 5. Intermittent fires related to vapor intrusion and odor complaints at the Hartford site 

have affected residences throughout the Village of Hartford. Subsequent investigations by a group of 

potentially responsible parties, known as the Hartford Working Group (HWG), have detected extensive 

hydrocarbon contamination beneath the site. The suggestions provided in this report are intended to 

provide input to the HWG so characterization and remedial design can be optimized. 

1.1 THE TRIAD APPROACH 

The START project team submitted a request for OSRTI to evaluate the planned approach for field 

activities to be conducted at the Hartford site, and in particular, to review the results obtained using a cone 

penetrometer test (CPT) equipped with the Rapid Optical Screening Tool (ROST). OSRTI authorized 

Tetra Tech to provide a set of comprehensive suggestions about the project as a whole, keeping in mind 

the most urgent needs at the Hartford site and the principles of the Triad approach. This assignment was 

based on review of on-going project documents and subsequent discussions with the Region 5 on-scene 

coordinators (OSC) and State of Illinois Environmental Protection Agency (IEPA) representatives. The 

suggestions provided are intended as a starting point for refining the existing conceptual site model 

(CSM) for the Hartford site so that an effective remedy can be designed and implemented as quickly as 

possible. 

The Triad approach emphasizes the need for an aggressive, up-front systematic planning process to 

integrate dynamic work strategies and real-time measurements during site characterization and remedial 

design to streamline the cleanup process. The Triad approach also stresses a continuously refined, 

interactive process that relies on innovative technologies and strategies to increase the weight of evidence 

generated to support decision-making at environmental cleanup sites. 

OSRTI is promoting the Triad approach as a means for streamlining site characterizations and 

remediation to improve cleanup decisions at Superfund, Resource Conservation and Recovery Act 
2

(RCRA), Brownfields, and other revitalization sites. The Triad approach is becoming more widely 

accepted and used by many EPA regions, states, and local governments. The principles and tools used 

with the Triad approach have been demonstrated to reduce schedules and budgets required to reach 

project milestones at many sites across the country. OSTRI has forged partnerships with the U.S. 

Department of Energy, the U.S. Army Corps of Engineers, and the Interstate Technology Regulatory 

Council (ITRC). These partnerships have been forged to document use of the Triad approach at small and 

large sites to expedite reaching project milestones more quickly and economically while increasing the 

level of confidence in project decisions. 

1.2 BACKGROUND 

The Hartford site is located in the northern portion of the Village of Hartford, Illinois, along the historical 

edges of the active Mississippi River channel (Figure 1). Activities are currently being carried out at the 

Hartford site to mitigate hazards from vapor intrusion identified within the limits of the Village of 

Hartford. From 1966 through 1990, intermittent house fires occurred along East Watkins Street, East 

Date Street, and several other streets. More recently, homeowners have registered complaints about 

petroleum hydrocarbon odors that triggered the need to temporarily relocate the occupants of several 

households. Because of the concern related to petroleum hydrocarbon odor, EPA identified project 

objectives that included implementing effective short- and long-term vapor mitigation measures and 

delineating free phase and vapor phase hydrocarbons to support final remediation objectives. 

A series of documents were reviewed in preparing this report. The documents Tetra Tech reviewed 

primarily address the geology and hydrogeology of the site, characterization and delineation of 

hydrocarbon impacts at the site, and mitigation of vapor intrusion. The suggestions provided in this 

report were prepared based on information obtained from references listed in the bibliography provided as 

part of this report. Clayton Group Services (Clayton) also provided valuable support in terms of raw data 

and files required to prepare these suggestions. 

Tetra Tech’s OSRTI support staff became involved at the Hartford site in February 2004. The data 

provided in this revised report were updated to include results available as of February 2006. Overall 

conclusions presented in this report have also been updated based on more recent results and reports. 

In support of the project team’s objectives as stated in various work plans, Tetra Tech compiled the 

attached figures to support development of a refined CSM for the Hartford site. A Triad systematic 
3

planning process relies heavily on the CSM as the primary tool to focus activities where they can provide 

the greatest value to decision-making and be used to identify data gaps, which may need to be filled to 

achieve project milestones. The CSM is also used to identify an optimal sequence of activities. 

Many practitioners are accustomed to using specific types of CSMs, such as a geological or 

hydrogeologic CSM or a pathway-receptor diagram as is often used by the risk assessment community. 

Triad practitioners use these forms of a CSM, along with others. A Triad-type CSM also identifies the 

decision logic: a systematic process to identify and refine project decisions. Factors such as source 

geochemistry, the nature of any possible remedies, and practical considerations are weighed in 

establishing the most efficient and logical sequence of activities needed to address project issues and 

reach project milestones. 

1.3 PROJECT OBJECTIVES 

Tetra Tech has identified the following project requirements based on a review of the Administrative 

Order on Consent (AOC) and on discussions with the project team: 

• “Abate any imminent and substantial threat to the public health or welfare in the area. More 

specifically any threat to fish, shellfish and wildlife, public and private property, habitat, and 

other living and nonliving natural resources” (Article 3 of the order). 

• “Specific attention is to be paid to the investigation of the source and extent of contamination, 

implementation of EPA approved interim measures, and design of an active recovery system 

designed to abate the on-going threat of discharge to the Mississippi River” (Article 38 of the 

order). 

• “Conduct a vapor extraction pilot test and provide options for improving and extending the 

existing vapor control system” (Article 43 of the order). 

• “Implement a sentinel well monitoring program” (Article 47 of the order). 

• “Establish the extent of dissolved phase hydrocarbons” (Article 51 of the order). 

• “Identify preferential pathways such as utilities and pipelines and establish the extent of 

vapor phase and free phase hydrocarbons which could be impacting human health and the 

environment at the Hartford site” (Article 52 of the order). 

1.4 PRINCIPAL STUDY QUESTIONS 

Tetra Tech developed the following principal study questions based on the stated objectives in the AOC 

and on review of historical data available for the Hartford site. 
4

1. What are the key, geologic, hydrogeologic, source, and or preferred pathway related factors that 

might control: 

(a) The release of petroleum fuel related vapors that pose a potential threat to human health and 

the environment. 

(b) Migration of free product and dissolved phase contamination in and away from potential 

source areas? 

2. How can these factors be used collaboratively along with design optimization tools to expedite 

installation of: 

(a) A vapor mitigation system? 

(b) A free product extraction system? 

(c) A release control and monitoring system for groundwater and surface water? 

The following sections of this report examine elements of the preliminary CSM for the Hartford site and 

demonstrate how they relate to the principal study questions. The intent is to identify physical 

characteristics of the Hartford site that can facilitate planning additional investigations. As the 

preliminary CSM is refined, the scale of heterogeneity and variation in environmental conditions can be 

understood in sufficient detail as to support implementation of an effective remedy. In addition, a mature 

CSM will allow the project team to select appropriate sample locations and sample densities and apply 

innovative strategies in the most efficient way possible given the physical constraints of the project. 
5

2.0 PRELIMINARY CONCEPTUAL SITE MODEL 

Efforts to mitigate vapors and other adverse environmental conditions at the Hartford site will be guided 

by the project team’s understanding of several key elements of the preliminary CSM. These elements of 

the preliminary CSM include, but may not be limited to, the following: 

• Geology and hydrogeology beneath the Hartford site 

• Thickness of free product and dissolved phase contamination and proximity to preferred 

pathways 

• Chemistry and geochemistry of the free product and dissolved-phase contamination 

Limited data are available on the chemistry and geochemistry of the contamination beneath the Hartford 

site; therefore, interpretive efforts focus on the relationships among the geology, hydrology, and 

contaminant distributions across and surrounding the Hartford site. Tetra Tech attempted to link potential 

preferred migration pathways with these factors to identify when and where additional investigation 

might be warranted. However, details on the configurations of underground utilities or sewer lines were 

not available when these suggestions were developed; therefore, this link was not fully developed. 

General suggestions are provided on the type and quantity of chemical and geochemical data needed to 

support implementation of an effective remedy at the site. 

Tetra Tech has developed work products based on the data provided in the references associated with this 

report. The work products include a generalized regional cross section (Figure 2) to show the 

approximate relationship between the Cahokia Alluvium and the underlying Main Sand. The Cahokia 

Alluvium contains silty or clayey sand units of limited extent, such as the North Olive, Rand, and EPA 

Strata, as well as fine-grained silty clay layers. The position of the Hartford site on the cross section in 

Figure 2 shows the potential for hydrocarbon contamination to affect both surface water and potential 

drinking water aquifers adjacent to the site. 

Figure 3 is an enlargement of the Hartford site area that shows the general relationships between specific 

sand units known to be present. The estimated groundwater flow direction is shown to be toward the 

Mississippi River and may vary significantly between individual sand units at the Hartford site. 

Based on the limited piezometric surface data that are currently available, the direction of groundwater 

flow adjacent to the Mississippi River near the Hartford site can trend from directly toward the river to 
6

directly away from the river. The direction of groundwater flow may fluctuate in response to changes in 

the river’s elevation and local groundwater pumping. Significant changes in direction of flow between 

aquifers over time is demonstrated by the potentiometric surface maps provided in “Work Plan - 

Dissolved Phase Groundwater Investigation, The Hartford Area Hydrocarbon Plume Site” (Clayton 

2004d) Figures 2-5 through 2-10. 

Figure 4 is a CSM prepared by compiling data from the “FPH CPT/ROST Subsurface Investigation 

Report and FPH Monitoring Well and Soil Sampling Plan for the Village of Hartford, Illinois” (Clayton 

2004b) and results from the “Site Wide Free Product Investigation” (Clayton 2006b). Figure 4 shows 

site-specific geological relationships and the extent of hydrocarbon contamination identified along select 

cross sections indicated on the block layout shown in the upper left-hand corner. The blocks extend 

beyond the boundaries of the Hartford site to show expected geologic relationships; however, data were 

not available for the areas surrounding the Hartford site when this report was generated. Although CSMs 

of this type are useful, they also introduce an element of spatial bias in that only select cross-sections can 

be presented. This same bias is not as significant in the isopach and top of formation maps discussed later 

in this report and used for understanding key geologic, hydrogeologic, and contaminant relationships. 

2.1 CURRENTLY IDENTIFIED REGIONAL DATA GAPS 

Based on information provided by Clayton, free product does appear to be moving off-site to the 

northwest. Data available for the site have been improved over the last 18 months. Figure 5 shows the 

locations where ROST data have been collected. The extent of the free product plume and the associated 

dissolved-phase plume have been adequately delineated in terms of the nature and extent, but additional 

characterization may be necessary to finalize system design and optimization. Significant data gaps 

remain, particularly in the design of optimized soil vapor extraction and product removal systems. 

2.2 GENERAL SUGGESTIONS FOR FILLING REGIONAL DATA GAPS 

ROST data have been collected in upgradient source areas from beneath the Premcor refinery (Clayton 

2006b), but similar investigations are needed for other surrounding properties to assure that any proposed 

remedies are reliable. Historical information on upgradient sources should also be compiled as available. 

Data for soil and groundwater in down gradient areas have been used to delineate the extent of the 

dissolve phase associated with the product plume (Clayton 2006a). A higher density of data is needed 
7

around source areas where geologic conditions are favorable for vapor intrusion and product removal is 

possible to improve the efficiency of the soil vapor extraction (SVE) and product removal systems. The 

specific locations and types of data suggested for collection in and immediately surrounding the Hartford 

site are also discussed in more detail later in this report. 

2.3 GEOLOGY, HYDROGEOLOGY, AND CONTAMINANT DISTRIBUTIONS 

According to “Sedimentary Environments: Processes, Facies and Stratigraphy,” (Reading 1996), the 

depositional environment beneath the Hartford site can be thought of as a mixed load river avulsion zone. 

The Hartford site is located in an area where the Mississippi River has shifted its position in recent 

geologic time, in a process referred to as an “avulsion” of the river channel. An avulsion occurs when the 

river breaches its natural levee and cuts a new channel in the floodplain. The river bed load is called a 

mixed load because widely variable sediment grain size — ranging from finer-grained levee deposits to 

coarse sands — can be deposited across a broad avulsion band such as is shown in Figure 6. These 

fluvial processes create a highly heterogeneous sediment package. 

The typical sedimentary sequence includes thick sequences of sheet-like channel sands, lenticular splay 

sands, fine-grained levee, and floodplain deposits. Figure 7 depicts the variety of deposits that are 

generally associated with fluvial deposits in a major river avulsion band. Figures 6 and 7 are schematic 

diagrams and are not site-specific, but near-surface fine-grained sediments generally grade with depth to 

massive sands units. Although the cross section shown in Figure 7 is theoretical, site-specific cross 

sections provided in the “FPH CPT/ROST Subsurface Investigation Report and FPH Monitoring Well 

and Soil Sampling Plan for the Village of Hartford, Illinois” (Clayton, 2004b) seem to concur with this 

generalized geologic sequence. Keeping in mind the two principal study questions, this geologic setting 

suggests that better delineation of fine-grained sediments will yield important information on locations 

where vapors might be expected to be present at the highest concentrations. Fine-grained sediments can 

be substantial barriers to vapor-phase, as well as free-phase and dissolved–phase, hydrocarbons. Finergrained sediments can also act as long-term source locations and pose significant challenges to source 

mitigation. 

Tetra Tech’s experience with free-product sites suggests that addressing coarse-grained contaminated 

aquifers without also addressing contamination in fine-grained sediments will reduce the effectiveness of 

a remedy. For example, applying high vacuums to coarse-grained sands can remove substantial quantities 
8

of free product from the sand units. However, once the system is turned off, residual contamination 

bound to fine-grained sediment units can re-contaminate the aquifer. 

Based on the schematic diagrams shown in Figure 6 and 7, sands tend to thicken and merge toward the 

present-day river and can be in direct hydraulic communication with the river. Therefore, dissolved phase 

contamination may be discharged to the river. Thick sections of more fine-grained materials or levee 

deposits are also expected around the edges of the former channel sand deposits. Currently, vertical and 

lateral piezometric, geologic, and contaminant distribution data are insufficient, both inside and outside of 

the Hartford site boundaries, to begin to construct a detailed regional CSM adequate to address the 

requirements stipulated in the AOC for the Hartford area. 

2.3.1 ROST Results, Contaminant Transport, and Source Areas 

The response of the ROST to petroleum hydrocarbon contamination can be roughly correlated with the 

presence or absence of product (Tetra Tech 2004). With this in mind, the ROST responses (as shown as 

red, yellow, green and blue color bands depending on the range of hydrocarbons) in Figure 4 can be 

examined to distinguish primary sources from areas where contaminant migration may have resulted from 

transport of free-phase hydrocarbon along the top of the water table. Product source areas are generally 

indicated by ROST responses at depths at the surface to 10 feet below ground surface (bgs), depending on 

whether the release is suspected to have occurred at the surface or below a buried pipeline. From a 

review of Figure 4, it is apparent that source material (above 20 feet bgs) is present primarily along the 

eastern, western, and northern edges of the Hartford site. One exception is the area beneath the river 

pipeline that runs along Elm Street. New ROST data in this area also indicate the presence of free 

product at depths starting at approximately 8 feet. Most of the other product contamination indicated in 

the ROST responses is present near the water table or the smear zone, which is defined as the region 

where the upward and downward fluctuations in the groundwater table spread hydrocarbon contamination 

across a greater vertical interval of the soil. It is anticipated that additional surface source areas will be 

identified as the density of data for the site increases. 

2.3.1.1 ROST Results and Product Recovery Challenges 

As discussed in many of the reports reviewed in preparing these suggestions, most of the recorded 

incidents of fire and odors occur during high stands in groundwater. A review of Tables 2-1 through 2-3 

of the work plan (Clayton 2004a) suggests that free product thickness can increase dramatically as water 
9

levels rise. This relationship is particularly evident at well HMW-22, suggesting that product recovery 

may need to focus on wells screened across intervals that correspond to high stands in water levels. 

Water is sometimes used to enhance the secondary recovery of petroleum in an oil field, although, 

fluctuations in water levels may also act as a hydraulic pump to enhance product recovery. 

The relationship of apparent hydrocarbon sources to minimum and maximum groundwater levels can be 

used to focus areas where different types of cleanup might be most effective. For example, vapor 

extraction technologies could be used with only a minimal need for direct free product recovery in areas 

where little or no source material is located at or below a low stand in groundwater if the product present 

is in the gasoline range. Conversely, the focus of cleanup efforts might be on collecting free product 

during high stands in the water table where source material is present in the smear zone or below the 

water table. However, it is important that current efforts focus on monitoring both changes in water 

levels and in observed free product thickness on a finer scale than in the past. 

At present, the project team has installed nested piezometers or extraction wells in each of the primary 

sand units and screened them across the upper portion or across the entire sand unit where the thickness 

permits (Clayton 2004b). This strategy may be inefficient, however, based on the observation that much 

of the free product underlying the Hartford site is likely present in the smear zone below the upper sand 

units. Free product recovery should be directed at those areas where thick columns of product are 

observed and should focus on design of a recovery system that target zones for removal based on geologic 

conditions and the proximity of product and the water table. 

It is apparent from the ROST response observed in potential near-surface source areas, such as are 

indicated near ROST locations HROST-6 and HROST-10, that near-surface source areas are limited in 

extent. However, the heterogeneity of these areas indicates variation on a finer scale than can be 

understood based on existing ROST results. Therefore, additional characterization is needed before nearsurface source areas can be addressed adequately. Outside of near-surface source areas, it may be 

possible to define regional trends in geology, hydrology, and product thicknesses and then to design free 

product removal and vapor intrusion mitigation systems on a more regional scale. 

2.3.2 Sand and Clay Isopach, Formation Top, and Free Product Thickness Maps 

Tetra Tech has developed top of stratum and hydrocarbon product thickness maps and top of formation 

and product ROST response maps (Figures 8 through 16) for each of the four major strata (North Olive, 
10

Rand, EPA, and Main sands) and the silty clay units that separate them. In addition, Tetra Tech prepared 

maps that show the top of free product (heavy, mid-range, and light range) and total product thickness 

(Figure 17 and 18). These maps were developed to identify (1) areas where vapor intrusion issues might 

be greatest, (2) areas where design of a product extraction system may be warranted, and (3) areas where 

monitoring the dissolved-phase plume or where additional characterization is needed. An isopach map of 

the total silty clay (Figure 12) has been developed, along with a map to indicate where the sand units may 

intersect known potential preferred pathways such as sewer lines and other buried utilities (Figure 19), as 

a first attempt at a more sophisticated level of interpretation. 

Figure 19 is an example of the type of work product that could be important, as the CSM is refined. The 

geologic, hydrogeologic, and contaminant characteristics provided in Figures 8 through 18 can be 

combined on composite maps to drive a dynamic work strategy and guide future investigations. 

However, any additional integration of the materials presented or discussed in this report is beyond the 

scope of the support available through OSRTI to the Hartford Working Group and EPA Region 5. 

The potential for vapor intrusion is likely highest where the uppermost extents of permeable sand units 

are closest to the surface, the total thickness of fine-grained alluvial deposits is lowest, and the total 

thickness of sand and product is the greatest. The maps discussed in the following sections attempt to 

identify specific geologic, hydrogeologic, and free product relationships that could directly influence the 

fate and transport of free product, distributions of vapor-phase contaminants, and distributions of 

dissolved-phase hydrocarbons. 

2.3.2.1 North Olive Sand Maps 

It appears that the North Olive Stratum thins across the central portion of the Hartford site and terminates 

here (i.e pinches out). Figure 8 shows the isopach thickness of the North Olive Stratum. This pinching 

out suggests that the North Olive Stratum is not in direct hydraulic communication with either the Rand 

or Main Sands except in the southeastern portion of the site, where the North Olive merges with the Main 

Sand. Free product or vapors within the North Olive unit cease beyond a point, as suggested by the 

general relationship between reported fires and the extent of the North Olive stratum. 

Product was also detected in ROST locations HROST 51 and HROST 52 (Figure 8), where the North 

Olive merges with the Main Sand. Therefore, the potential for direct communication of contaminants 
11

from the North Olive Stratum into the Main Sand, or vice versa, exists in this area. Multiple fire events 

have occurred in this area. 

As mentioned previously and as shown in the isopach of the North Olive Stratum in Figure 9, areas where 

fires have been historically reported across the Hartford site seem to correspond with areas where a 

measurable thickness of the North Olive Stratum has been mapped. It has also been observed that the 

silty clay layers thin out above the Main and Rand strata in this area. 

2.3.2.2 Rand Stratum Maps 

The Rand Stratum merges into the Main Sand adjacent to the eastern boundary of the Village of Hartford, 

as shown in Figure 10. Figure 11 presents the thickness of the Rand Stratum in feet. Contamination 

within the Rand Stratum in the southeastern portion of the site could therefore easily migrate in the vapor 

or free phase from the Rand Stratum into the area enclosed by the 12-foot bgs contour in the Main Sand. 

A potential also exists for contamination within the Rand Stratum near ROST locations HROST 26 and 

33 (Figure 5) to migrate up into the structural high in the Main Sand shown in the north-central portion of 

the village. 

Evaluation of the isopach of the silty clay above the Rand and Main sands further supports why fires have 

not been recorded in and around ROST locations HROST 23 and 24 (Figure 4). The silty clay in this area 

thickens to nearly 20 feet (Figure 12). The thickness of the silty clay above the Rand or Main Sand is 

generally less than 12 feet and the North Olive Stratum is also present throughout the area where fires 

have been recorded. 

The thickening of the clay in this area may indicate that the need to mitigate vapors may be less urgent. 

However, the hydrocarbons appear thickest in this area. Product recovery in this location may be 

warranted because of the potential for product to move from this area toward the northwest, where the 

silty clay unit thins dramatically and fires have been reported. 

2.3.2.3 EPA Stratum Maps 

The EPA Stratum is limited in extent, as shown in Figures 13 and 14. However, contamination in the 

EPA Stratum would migrate directly up into the Main Sand in the northwest portion of the Hartford site. 
12

2.3.2.4 Main Sand Maps 

An isopach of the Main Sand could not be created because it represents the basal glacial outwash sand 

unit, which extends down to the limestone bedrock in the area. Stratigraphic information on the bottom 

of the unit is not available. An isopach of silty clay between the EPA stratum of Main Sand and the Rand 

stratum or the North Olive stratum is presented in Figure 15. The contour map of the top of the Main 

Sand (Figure 16) shows a northwest-trending structural high along the approximate axis of fires reported 

in the southern portion of the affected region beneath the village. This structural high is crudely aligned 

along the expected flow direction in the Main Sand, as depicted in the work plan (Clayton 2004d). This 

northwest-trending feature in the Main Sand suggests that a principal area of concern for contaminant 

migration away from the site could exist northwest of the current site boundaries. Migration of dissolvedand free-phase constituents might be expected downgradient of this structural high along the regional 

northwest direction of flow within the Main Sand. As will be discussed later in this section, product 

appears to extend off site and downgradient along this northwesterly trend (Clayton 2006a). The impacts 

from the presence of product west and north of the village are not thought to immediately affect the 

current remedial design efforts and are therefore not discussed further in this report. 

2.3.2.5 Light Range Petroleum Hydrocarbon Maps 

A large high in the top of the ROST response for lighter hydrocarbons is present along Elm Street 

(pipelines run from the refinery to the river along Elm Street). Figure 17 shows the approximate extent of 

lighter range, lower boiling point fuels in combination with the top of the ROST response. The depth of 

the response appears to coincide with the approximate depth of the pipelines in this area. Numerous spills 

have been recorded in this area and historical records for the pipelines indicate that these lines could have 

leaked throughout the history if their use. 

Heavier hydrocarbons have a greater peak height at higher wavelengths of absorbance, as indicated by 

greater peak heights on the right-hand side of the ROST output file (the dwell profile). When peak 

heights are greater on the left-hand side of these dwell profiles, the fuel at this spot in the contaminant 

plume is likely made up of hydrocarbons such as gasoline, which have lower boiling points, usually 

considered light range hydrocarbons. Diesel fuels might be considered a mid-range hydrocarbon product 

with greater peak heights in the center of the profile. Motor oil or weathered product, which has been in 

the ground for extended periods, is usually considered a heavy range hydrocarbon product. Based on the 
13

general results shown in Figure 17, it appears that the preponderance of hydrocarbons present across the 

site are in the gasoline range. 

2.3.2.6 Mid-Range Petroleum Hydrocarbon Maps 

The distribution of mid range hydrocarbons shown in Figure 17 seems to indicate the potential for the 

presence of two source areas for this type of petroleum product. One is located along the northeastern 

boundary of the site near ROST location HROST 6 and 10 and another is located near the northwestern 

boundary of the site near HROST 2. The nature and extent of mid-range hydrocarbons may influence 

their treatability and their tendency to cause vapor intrusion and will therefore need to be examined more 

closely. The specific chemistry and constituent makeup of each of the source types identified should be 

examined to determine: (1) site-specific action levels for vapor intrusion, and (2) site-specific action 

levels that can be used to assess the need for removal. These action levels will be driven by the chemistry 

and type of potential associated risk or hazard identified for the area of interest within the site. 

2.3.2.7 Heavy Range Petroleum Hydrocarbon Maps 

Figure 17 shows the limited extent of heavier range hydrocarbons at the Hartford site. As expected, the 

extent does not generally correspond to areas where fire hazards have been reported. Since heavy 

hydrocarbons products tend to sorb to the soil and are generally more viscous, they have less of a 

tendency to migrate away from primary source areas. Primary concerns in these areas should be focused 

on limiting the potential for direct contact. Chemicals of potential concern in surface soil in this area 

might include polynuclear aromatic hydrocarbons (PAH). A close inspection of the ROST profiles in this 

area does indicate the presence of light hydrocarbons beneath these apparent heavier hydrocarbon source 

areas. 

2.3.2.8 Total Petroleum Hydrocarbon Map 

Figure 18 shows the extent of the total ROST response to all three ranges of hydrocarbons. The largest 

thickness in ROST response is along Elm Street. This supports the large high in the ROST response of 

lighter range hydrocarbons in that same location. 
14

2.3.3 Interaction of Shallow Stratums with Sewers and Utilities 

Tetra Tech prepared Figure 19 to identify areas where preferred pathways (sewers) might intersect 

permeable stratum units, allowing hydrocarbons to accumulate at shallow depths. Figure 19 shows the 

location of product pipelines, municipal sewer mains, and shallow stratum units (with upper extents 

above 12 feet bgs). The map identifies the upper extents of shallow sand intervals (primarily the North 

Olive Stratum, but also the Main Sand in the southern portion of the Hartford site). The 12-foot bgs 

contour shown in this figure is significant because the depth of buried pipelines is approximately 12 feet 

bgs, as noted in the “Utility and Pipeline Investigation Work Plan, the Hartford Area Hydrocarbon Plume 

Site” (Clayton 2004f). This work plan did not indicate the depth of the municipal sewer mains, but it can 

be assumed that they are above the 10-foot bgs contour. Notably, a sewer main crosses the 8- to 10-foot 

bgs contour interval in the eastern portion of the village. Five buildings where fires have been reported 

are located within 100 feet of this sewer main. This map, like those previously discussed, should be 

considered when the working group prioritizes locations where sewer and utility investigations and 

design-related activities are planned. The HWG also may consider using the presence or absence of light 

or mid-range free product in the shallow sand units as a means of prioritizing when and where to focus 

remediation efforts for sewers and utilities. 

2.4 HYDROCARBON CHEMISTRY AND GEOCHEMISTRY 

The chemistry and geochemistry of hydrocarbon product, geologic formations, and groundwater beneath 

the Hartford site will have a strong influence on the effectiveness of any remedy. These and other 

physical factors such as moisture content, permeability, and effective porosity should be used in 

conjunction with one another to support the design of any potential remedy. The HWG has not focused 

on the chemistry of the product found beneath the Hartford site up to this point, as is indicated by 

responses to comments provided by Clayton to EPA Region 5 dated June 21, 2004, and titled “Letter to 

USEPA Region 5. Response to Comments to ROST Investigation Report and Work Plan.”) The response 

to U.S. EPA comment 1 part A, second sentence states, “It is Clayton’s opinion, based on experience at 

other petroleum sites, that the design of the remediation system will be primarily based upon geology of 

the area and the amount of product present not the type of product” (Clayton 2004e). 

Ignoring product-specific chemistry during remedial design could limit the effectiveness of any cleanup 

strategy. The petroleum industry has long recognized that the nature of various petroleum products can 

pose different challenges to extraction of petroleum from an oil reservoir. Heavier products often require 
15

more aggressive techniques to extract. For example, methods such as steam-enhanced recovery have 

been developed to address removal of heavier hydrocarbons where simple flooding methods have proven 

ineffective. 

Not only is further characterization of the nature of the product necessary; the physical properties of the 

petroleum hydrocarbons need to be understood so their fate and transport can be estimated and input to a 

model to support the evaluation of impacts to surface water in the area. Further characterization of the 

product is also suggested to support risk estimation and development of field-based action levels related 

to both vapor intrusion and dissolved-phase fate and transport issues. 

For example, one of the questions at the Hartford site is the impact of removing the free product and 

dissolved-phase hydrocarbons will have on vapor intrusion. This issue is chemistry related. Petroleum 

hydrocarbons consist of complex mixtures of carbon, hydrogen, ammonia, sulfur compounds, and other 

constituents, such as lead and oxygenates, used to improve fuel performance. Each mixture has a 

susceptibility to treatment at a particular moisture level in soil that is related to its Henry’s Law constant. 

Therefore, the composition and physical properties of the mixture can affect the removal rate and 

estimated risk. Liquid-phase removal may also be affected by the chemical and physical properties of the 

free product, such as its tendency to form a physical or chemical emulsion that will be difficult to treat. 

Detailed data on chemistry, geochemistry, and physical properties are needed to design a system and then 

predict whether it can be successful in mitigating vapor or dissolved phase-related hazards. 

The HWG should consider implementing a robust chemical, geochemical, and physical properties 

characterization effort to begin to understand differences in product chemistry. The analytical suite 

should include, but not necessarily be limited to, the following: 

• Volatile organic analyses (using method 8260) 

• Semivolatile organic analysis (using method 8270) 

• PAH analyses (using modified method 8270 operated in the selective ion monitoring mode) 

• Viscosity and density analyses 

• Porosity, permeability, grain size, total organic carbon 

• Nonaqueous phase liquid (NAPL) saturation 

• Cation exchange capacity 
16

In addition to these chemical and physical property analyses, site-specific testing in the form of core 

column tests might be considered. These tests can also be performed in situ using innovative tools such 

as the Praxis Environmental Technologies, Inc. (Praxis ) PneuLog, which allows for the design of the 

SVE removal system to be optimized once a system has been installed. Since there is an existing system 

on site, this technology might be immediately applicable. 

Core column studies may be conducted when there are significant questions on the applicability of one of 

several alternatives for treatment, such as in the area near ROST location HROST 2. Pilot testing with 

PneuLog could be used to optimize and expand an existing system design in areas where SVE already 

appears to be the logical alternative, such as the area surrounding HROST 51. Chemical data, along with 

concentrations present, should be used to estimate any risk that requires treatment. Additional 

information on the use of core column and well product removal pilot testing can be made available from 

Tetra Tech on request. 
17

3.0 SUGGESTIONS FOR OPTIMIZING CLEANUP SYSTEM 

DESIGN AND IMPLEMENTATION 

In the review of the primary study questions and the information presented thus far in this report, the 

working group faces the following issues at the Hartford site that will eventually need to be addressed: 

• Immediate physical hazards, such as fires that result from vapor intrusion 

• Impacts to human health from vapors 

• Impacts from contaminated soil in the vadose zone to groundwater 

• Impacts to groundwater from free product in the smear and saturated zone 

• Impacts from dissolved- and free-phase hydrocarbons to surface water 

A robust set of suggestions for each of these issues is beyond the scope of the support that Tetra Tech can 

provide under its current assignment for OSRTI. Therefore, the focus in this section is on providing 

general observational data and suggestions for most of the key elements that should be evaluated. HWG 

can then more fully evaluate the types of specific activities and decisions that will need to be made. 

Installing and sampling vapor monitoring probes (VMP) is under way at the Hartford site to evaluate the 

potential hazards and risks to human health from vapors. The maps and suggestions provided by Tetra 

Tech in this document are intended to identify areas where the interaction among the sewer and utility 

system, geologic features, and free product should be further evaluated through VMPs. In addition, the 

maps and suggestions provided indicate where free product may be collecting in stratigraphic traps, such 

as the area near ROST location HROST 51. Tetra Tech believes this area might be more amenable to 

SVE than other areas where the presence of more fine-grained materials might pose a challenge to the use 

of SVE. Suggestions are also provided that identify areas where free product extraction should be the 

focus of the HWG efforts. Free product extraction may be warranted where free product is found at the 

greatest thicknesses (Figure 18) and has the greatest potential to continue to contribute to migration of 

dissolved-phase contamination away from source areas. 

The current data set lacks sufficient information on hydrology and the chemistry and spatial distribution 

of contaminants to support the design of a free product extraction or dissolved-phase monitoring and 

treatment system. Therefore, this section discusses use of collaborative data sets and similar approaches 

to optimize the design of the vapor extraction system, investigate the dissolved-phase contamination, 

evaluate methods to remove free product from the smear and saturated zones, and implement an 

integrated monitoring system to track the progress of the remedial action. 
18

3.1 SOIL VAPOR EXTRACTION SYSTEM DESIGN AND OPTIMIZATION 

As mentioned previously, SVE may be an effective alternative in source areas at the Hartford site, 

particularly where free product is present above the water table and geologic conditions are favorable. 

PneuLog is a technology designed to reduce long-term operational costs and accelerate cleanup by 

optimizing SVE systems in unsaturated zones. The PneuLog technology uses in-well instrumentation to 

measure air permeability and contamination production continuously throughout an extraction well within 

the screened interval during SVE. This technology is intended to improve the assessment of geologic 

heterogeneity within the screened intervals of individual wells and identify mass transfer constraints in 

the vadose zone. Data from several wells can be used to optimize a cleanup strategy and estimate 

operation times needed to meet closure requirements. 

Tetra Tech proposes using PneuLog technology to support the evaluation and optimization of any SVE 

systems planned for the Hartford site. Tetra Tech suggests that a dynamic work strategy may be used as 

an alternative to the traditional phased approach to limit the need for mobilizations and thus streamline 

product removal and vapor mitigation. The PneuLog technology can be used not only to target zones 

with the highest concentration in vapors; it can also be used to size pumps where contamination in 

concentrated in fine-grained soils. In contrast, conventional SVE design and optimization procedures rely 

on empirical data that do not adequately evaluate mass transfer constraints, limiting the effectiveness of 

the remedy. As a result, conventional systems may be overbuilt, inefficient, and expensive to operate. 

The PneuLog approach incorporates short-term SVE testing with pneumatic well logging to delineate the 

horizontal and vertical extent of contaminants and quantify the permeability of soils throughout the 

screened interval. The PneuLog test is repeatable, and multiple deployments can track the progress of 

cleanup when combined with technologies such as passive or active soil gas surveys and vapor probe 

analysis in a collaborative data set. When used in a number of wells, this approach provides a more 

complete and accurate baseline evaluation for design and optimization of SVE systems. In addition, data 

on soil permeability and airflow rate data provided by PneuLog can be used in models to estimate 

removal action timeframes. 

3.1.1 Traditional Vadose Zone Profiling and Monitoring Techniques 

Traditional methods of delineating vadose zone contamination to implement SVE involve soil gas surveys 

and multipoint vapor probe sampling. Traditional methods of developing vertical contaminant profiles 
19

involve installing discrete VMPs at multiple depths at a single location. Similarly, traditional methods of 

developing lithology profiles require continuous split spoon sampling. SVE pilot testing is used to 

develop soil vapor production rates, contaminant concentrations, and radius of influence (ROI) 

information on a site-wide scale. 

Before an SVE system can be constructed, the following types of data should be collected at specific 

targeted locations within the Hartford site at a density sufficient to characterize the heterogeneity of the 

hydrogeologic setting: 

• Contaminant type and associated volatility 

• Permeability of the soil 

• Soil structure and stratification 

• Soil moisture content 

• Depth to groundwater and changes in product thickness and water level over time 

The following sections briefly summarize methods Tetra Tech suggests for horizontal and vertical 

profiling of the vadose zone. 

3.1.2 Soil Sampling 

Vertical profiling is an important component of site characterization and CSM development. Before 

cleanup technologies for soil treatment can be evaluated, a site is usually investigated to characterize the 

geology and vertical distribution of contaminants on a site-specific scale. Lithologic and geotechnical 

parameters are usually collected at various depth intervals. New tools such as the membrane interface 

probe (MIP) and other real-time sensors, or near-continuously reading instruments such as PneuLog, are 

changing existing ideas about how contaminants are distributed in the environment. Small-scale 

heterogeneity seems to be the rule, rather than the exception, and can severely impair the effectiveness of 

a remedy. 

Soil structure and stratification are important to the effectiveness of SVE because they affect vapor flow 

within the soil matrix under SVE conditions. For instance, it is widely accepted that SVE is generally 

less effective in moist, silty, or clayey soils. Structural characteristics (such as layering and fractures) can 

create preferential flow pathways that can short-circuit SVE systems, resulting in extended remedial 
20

timeframes if the extraction points are positioned such that the induced airflow bypasses the area of 

contamination. 

Soil borings are typically completed using a hollow stem auger (HSA) or direct-push probe such as a 

Geoprobe. These borings are drilled to collect a continuous soil sample and characterize the subsurface. 

Instruments can be deployed with direct-push drilling equipment that can record nearly continuous 

measurements of the soil’s physical and chemical characteristics, resulting in development of a 

continuous vertical profile. The MIP technology provides a continuous log of soil conductivity and the 

volatile organic compound (VOC) concentration as it is driven into the soil. The Simulprober technology 

is a modified split spoon sampler that can also be used with conventional direct-push drilling techniques 

and is intended to collect continuous soil and soil gas samples and conduct in situ single-point slug tests. 

These tools have significant limitations; an investigation must proceed with these limitations in mind and 

should not be conducted without consulting with an expert who has significant experience with these 

instruments. 

3.1.3 Soil Permeability Testing 

Permeability affects the rate of air and vapor movement through the soil: the higher the permeability of 

the soil, the faster the movement and (ideally) the greater the quantity of vapors that can be extracted. 

High moisture content in soils can reduce permeability and, consequently, the effectiveness of SVE by 

restricting the flow of air through soil pores. Fine-grained soils produce a thicker capillary fringe than 

coarse-grained soils. SVE is generally not effective in treating soils below the top of the capillary fringe. 

Pumps can be used to depress the water table; however, pumping to lower the water table is not feasible 

because of the volume of water in the aquifers beneath the Hartford site. Site-specific data on water 

levels and soil permeability will be integral in optimizing the effectiveness of SVE or when SVE is 

selected as the preferred remedial alternative. Combining this information with characterization data on a 

finer scale can help engineers understand the limitations of a proposed system. For example, a site where 

the CSM indicates contamination in the finer-grained portions of the soil profile may not be effectively 

remediated using SVE alone. This level of understanding on the potential for SVE as a remedy at specific 

locations within the Hartford site (such as near HROST-2) can be developed only by collecting data on 

soil permeability and contaminant concentration on a finer scale using pneumatic tests. 
21

3.1.4 Vapor Monitoring Points 

VMPs are the traditional method for developing initial vertical contaminant profiles at SVE sites and may 

also be used as a tool for optimizing existing systems. VMPs are constructed by installing several 

relatively short-screened interval wells separated by bentonite seals within a single borehole. VMPs are 

used to measure vertical variations of vapor-phase contaminant concentrations and pressure and vacuum 

response (and, indirectly, permeability) along the soil profile when they are placed at varying depth 

intervals. Soil vapor chemistry is assessed at each discrete depth interval by withdrawing and analyzing 

soil vapor samples. The vacuum pressure required to extract the soil vapor from each individually 

screened depth interval indirectly indicates permeability. Soil permeability dictates the amount of 

airflow. Relatively high airflow indicates higher permeability, and relatively low airflow indicates low 

permeability. 

Continuous soil borings are typically used to install VMPs. This method can be labor intensive and does 

not yield a continuous soil profile. Optimal locations for these points are best identified using highquality geologic, contaminant distribution, and pneumatic test data. Conducting MIP profiles or a 

headspace soil gas survey before the VMPs are installed can improve efficiency when vapor probes are 

designed and installed. Installing VMPs without these data can result in poor system design and 

ineffectiveness of the remedy. 

3.1.5 SVE Pilot Testing 

A pilot test is recommended for evaluating SVE effectiveness and design parameters at any site, 

particularly where SVE is expected to be only marginally to moderately effective. Data provided by pilot 

testing are necessary to properly design the full-scale SVE system. Pilot tests also provide information on 

the concentration of VOCs that are likely to be extracted during the early stages of operation of the SVE 

system. 

Various extraction rates and wellhead vacuums must be evaluated to estimate optimal operating 

conditions. Pilot studies typically involve extraction of soil vapors for a short period (1 to 30 days) from 

a single extraction well, which may be an existing monitoring well at the Hartford site. However, longer 

pilot studies (up to 6 months) using more than one extraction well may be appropriate for larger sites. 

More information on methods for system operation can be found in “Innovative Site Remediation 

Technology, Design and Application, Volume 7, Vacuum Extraction and Air Sparging” (EPA 1998). 
22

Vapor concentrations should be measured at two or more intervals during the pilot study to estimate 

initial vapor concentrations that may be expected during operation of a full-scale system. The vapor 

concentration, vapor extraction rate, and vacuum data should also be used in the design process to select 

extraction and treatment equipment. 

Estimating the ROI of each extraction point is important for proper design of an SVE system. The ROI is 

defined as the greatest distance from an extraction well where a sufficient vacuum and vapor flow can be 

induced to adequately enhance volatilization and extraction of contaminants in the soil. Practitioners can 

increase their confidence that the pilot test design accommodates site conditions with better 

characterization methods and pneumatic logging techniques. 

3.2 PNEUMATIC WELL LOGGING TECHNOLOGY 

Pneumatic well logging is a technology developed by Praxis, which is designed to optimize SVE design 

and operation. Pneumatic well logging is performed by simultaneously measuring cumulative airflow and 

contaminant vapor concentrations vertically along the depth of an extraction well screen during active 

SVE. To record these measurements, a flow sensor is moved up through the well while vapor extraction 

and soil gas samples are continuously collected and analyzed. Collecting these measurements at a 

representative number of wells can yield a three-dimensional picture of the extent of soil contamination at 

a site as well as the distribution of soil permeability. These measurements, in conjunction with traditional 

sampling methods, can yield a more thorough understanding of a site and how an SVE system can be 

optimized. This more thorough understanding is possible because PneuLog technology provides 

information that other technologies cannot, such as soil permeability and mass loading of the vadose 

zone. 

3.2.1 Equipment 

The equipment used for PneuLog pneumatic well logging is illustrated in Exhibit 1. The PneuLog 

instrument is attached to a cable, which passes through alignment pulleys and a vacuum-tight fitting at the 

wellhead. The instrumentation is raised or lowered by a cable wound around a motorized reel. The 

logging proceeds at a rate of 8 feet per minute along the screen in the SVE extraction well. Sensors in the 

pulley assembly indicate the depth of the measurement. Electrical leads connect the flow sensor to a data 

acquisition system located on the motorized reel. A vapor sampling tube connects the sample port on the 

instrument to a vacuum pump, also located on the reel. The sampling pump draws a continuous stream of 
23

P ID

Tube for Vapor Sample

Transfer

Air Velocity Sensor

Cable

Reel

Vacuum on

Wellhead

Applied by

Blower

Computer

RealTime

View of

Data

Cable

Alignment

Assembly

Vacuum Pump for

Vapor Samples

air through the sampling tube to the surface, where it is analyzed for VOCs and other compounds of 

interest (such as oxygen and carbon dioxide). A photoionization detector (PID) is used to provide a 

continuous reading of total VOC concentrations. Summa canister samples can be collected for off-site 

analysis by gas chromatography and mass spectrometry to estimate compound-specific concentrations at 

discrete depths and to calibrate the PID readings. Supplemental vapor samples can be collected in Tedlar 

bags and analyzed on-site with a field gas chromatograph. 

Exhibit 1: Schematic of Pneumatic Well Logging Equipment 

3.2.2 Permeability Profiles 

The airflow from each soil layer is related to the cumulative airflow by a simple mass balance. The 

cumulative airflow measured below the soil layer is subtracted from the cumulative airflow measured 

above the soil layer to calculate the airflow from a soil layer. The soil permeability of the interval is then 

determined from Darcy’s law. The data and the analyses appear similar to output from borehole 

flowmeter testing in water wells. A typical cumulative gas flow measurement from PneuLog is provided 

in Part (a) of Exhibit 2, below. In this example, the well is screened from 12 to 32 feet bgs. As shown, 
24

the airflow from the bottom half of the well is essentially zero. The airflow increases steadily from 0 to 

28 standard cubic feet per minute (scfm) between 23 and 16.5 feet bgs as the instrument is raised through 

the screen. The steady flow increase indicates this soil interval has a relatively uniform permeability to 

air. Only 2.5 scfm of soil gas are added from 16.5 to 15 feet. The volumetric flow increases by 15 scfm 

in the next 1.5-foot interval up to 13.5 feet. The top 1.5 feet of the screen adds only 1 scfm to the total. 

Exhibit 2: Example Pneumatic Well Logging Results for Soil Permeability to Air 

Part (a) Part (b) 

The diagrams present an interpretation of the cumulative flow measurements as soil gas production 

proceeded. An effective air permeability profile can be generated using the soil gas production profile 

with multi-dimensional analytical or numerical airflow models. The permeability of an interval is 

proportional to the change in flow across the interval, its thickness, its depth below the surface, and the 

well vacuum according to Darcy’s law. Part (b) of Exhibit 2 reveals five soil strata along the screen. The 

permeability of the stratum intersected by the bottom half of the screen (yellow or light blocks) is 

relatively low since no measurable soil gas was produced. The geologist characterized the soil of this 

interval as silt. The air production rates for the soil intervals from 16.5 to 23 feet and 13.5 to 15 feet 

indicate coarse sand. These two sand intervals are separated by a 1.5-foot-thick silt interval. The soil at 
25

the top of the screen was also characterized as silt. This characterization of the physical properties is 

superior to a geological log and a typical air permeability test. The PneuLog results are usually consistent 

with the geologic observations; however, geologic logs provide little or no indication of potential air 

permeability. Without the pneumatic logging data, the permeability measured by typical testing is 

averaged over the screen interval and of the subsurface flow profile. It therefore cannot be quantified and 

well screens subsequently optimized. 

3.2.3 Concentration Profiles 

The measurement of VOC concentrations along the well screen indicates the distribution of VOCs in the 

screened interval. An example concentration log, which was collected simultaneously with the airflow 

log previously discussed, is presented in Part (a) of Exhibit 3, below. This concentration profile was 

obtained from a continuously reading PID that was calibrated to trichloroethylene (TCE) concentrations 

with on-site and off-site gas chromatographic analysis of vapor samples from discrete depths and the 

wellhead. The vapor concentration measured is lowest near the bottom of the screen and increases 

slightly up to a depth of about 28 feet. As the tool is raised higher in the well, the concentration increases 

sharply to a maximum at 26 feet and remains relatively high to a depth of 21 feet. The concentration then 

decreases steadily from 21 to 15 feet bgs. The concentration increases very slightly between 15 feet and 

the top of the screen. 

The increases and decreases in concentration observed can be combined with the depth-specific air 

production in a mass balance to estimate depth-specific soil gas concentrations. The PneuLog device 

simultaneously measures the flow rate and concentration versus depth. The change in the product of 

these two variables over a specified depth interval divided by the flow change is equal to the contaminant 

vapor concentration in the soils of the depth interval. Application of this relationship to the data shown in 

Exhibit 3 Part (a) yields the contaminant vapor concentration profile presented in Exhibit 3, Part (b). The 

highest concentration occurs in the low-permeability material that underlies the deeper sand interval. 

This high concentration indicates that the low-permeability interval creates a mass transfer constraint to 

SVE. 
26

Exhibit 3: Sample of Pneumatic Well Logging Results for Contaminant Product 

 Cum. TCE Conc. (mg/m3

) TCE Soil Gas Conc. (mg/m3) 

 Part (a) Part (b) 

Note: mg/m3 = Milligrams per cubic meter 

3.3 OPTIMIZING AN SVE SYSTEM AND IDENTIFYING SVE AS A VIABLE REMEDIAL 

ALTERNATIVE 

As illustrated by this example, pneumatic well logging provides a more thorough and appropriate site 

characterization than will traditional methods alone. Repeating the process in a representative number of 

wells can generate a three-dimensional description of the physical and chemical subsurface by correlating 

between locations. The technique also provides higher-quality data that can be used to more effectively 

design and optimize an SVE system. Soil strata near or below cleanup goals are quickly identified, and 

the extraction flow rate can be reduced or terminated from these layers. The operation can then be 

focused on strata where contaminants remain at concentrations above cleanup goals. This optimization 

could lead to cost savings by accelerating cleanup and lowering operation and maintenance costs. 

PneuLog can be used in conjunction with other new and improved methods of site characterization to 

build comprehensive data sets that can be used to evaluate when and if SVE is a viable alternative and 

even to decide when SVE is no longer needed. Real-time measurement technologies such as a MIP or 

laser induced fluorescence (LIF) provide contaminant distribution data that are independent of the 

5

10

15

20

25

30

35

100 150 200

3

Depth (feet)

0 100 200
27

permeability of the contaminated stratum. PneuLog, on the other hand, is biased by the permeability of 

the soil. Combining these two different types of data in a collaborative data set can provide practitioners 

with a better idea of whether SVE will be effective and the design specifications that are most 

appropriate. 

3.3.1 Technology Assessment 

Praxis developed the PneuLog technology to aid both site characterization and optimization of SVE 

systems. Tetra Tech’s evaluation of this technology revealed several advantages and disadvantages. The 

primary advantages of this technology are as follows: 

• A continuous vertical profile of contaminant concentration and soil permeability can be 

quickly developed for each SVE well on site. This profile represents average values for each 

major soil interval intersected by the vent well. 

• The use of progressive extraction, vapor sampling, and pneumatic logging of the wells as 

they are installed will provide guidance for locating additional wells to more adequately 

characterize the Hartford site. 

• The actual VOC concentrations in milligrams per cubic meter (mg/m3

) produced at specific 

intervals are measured. 

• The permeability, flow rate, and total VOC production for a section of screened interval can 

be estimated. This information is useful in optimizing or modifying vent wells and for sizing 

blowers and vapor treatment equipment for new or modified SVE systems. 

• The data are presented in a manner that is easy to interpret and highlights significant 

variations between intervals. When combined with other, more detailed, methods that can 

measure contaminant distribution regardless of permeability, the data can be used to decide 

when and if SVE will be effective or whether to modify the system. 

The primary disadvantages are as follows: 

• An SVE extraction well must be installed if one does not already exist. If SVE does not turn 

out to be appropriate for the Hartford site, then this site characterization method may be more 

expensive because installation of a well will generate soil cuttings and is labor intensive. 

• Pneumatic logging provides limited data from soil intervals that are not within the screened 

interval of the well. The ideal screened depths cannot be identified before the vent well is 

installed. However, PneuLog testing in a single-well pilot test could be used to more 

effectively locate well screens in a full-scale, multi-well SVE system. 

• Contamination from an overlying low-permeability layer may be detected at dilute 

concentrations in an underlying high-permeability layer. High levels of VOC contamination 

may be entering the vent well from one direction and be diluted by clean soil gas from other 

directions. The vent well tends to average VOC concentrations, and the PneuLog tool can 

measure only the average VOC concentration inside the well and the average permeability of 

the soil interval. 
28

Overall, a technology such as PneuLog is warranted because of the size of the Hartford site and the need 

for efficiency in implementing a cleanup strategy. Additional information and design considerations 

should be evaluated in conjunction with Praxis or an equivalent vendor of a similar technology. 

3.3.2 Monitoring the Effectiveness of a Cleanup Strategy 

A direct measurement approach should be used to monitor the impact of any cleanup strategy for the 

Hartford site. Passive soil gas probes placed at regular intervals in and around treatment zones to measure 

relative changes in concentration can be an economical way to accomplish this task. Alternately, VMP 

samples can be collected over time using a focused analytical program. Any analytical program for 

monitoring the effectiveness of the remedy needs to include not only contaminant-specific analysis, but 

should also monitor for explosive levels of less toxic petroleum fuel-related constituents. Action levels in 

the vapor phase will need to be agreed upon by all stakeholders before a cleanup strategy can be 

implemented.

Real-time measurement tools such as a mobile gas chromatograph should be considered initially as a 

method to economically increase the density of vapor sampling. More sensitive vapor probe 

measurements such as Summa canisters may be required as concentrations decrease and vapors are 

mitigated. The PneuLog itself can also be used to evaluate yields and the benefit of continued operation 

of an SVE system. 

3.4 GEOVIS VIDEO MICROPSCOPE ESTIMATES OF IN SITU NAPL SATURATIONS 

USING CPT TECHNOLOGY 

In addition to traditional methods for evaluating the potential for product removal at the site, Tetra Tech 

suggests that HWG consider GeoVIS as a method to increase the project team’s understanding of 

hydrocarbon saturations. Hydrocarbon saturations can be used to estimate where additional permeability 

and productivity testing using high-vacuum extraction may be warranted. Currently, the HWG proposes 

to base its product removal system design on one or two key locations where core data were collected and 

conditions were favorable for further testing (Clayton 2006c). Use of a limited set of results in the 

manner proposed could result in an ineffective remedial design and wasted project funds. 

The GeoVIS video microscope has the capability for collecting real-time in situ images of the subsurface 

soil environment for use in estimating soil porosity and light NAPL saturations. The GeoVIS system uses 
29

a miniature digital video camera coupled with magnification and focusing lens systems integrated into a 

cone penetrometer probe. The soil environment is imaged through a window in the probe and the video 

signal from the camera is returned to the surface where it can be viewed in real-time on a video monitor, 

recorded on a video recorder, or digitized (or any combination). When combined with lithology 

information obtained from CPT probe data and soil contamination estimations from LIF data, GeoVIS 

provides the small-scale tools necessary to identify thin layers of highly permeable material that provide a 

potential pathway for contaminant transport and removal, which could be overlooked easily through 

conventional means. It also provides a direct means for locating contamination source zones that have 

been difficult to localize using traditional sampling approaches. 

3.4.1 Equipment 

The equipment used for GeoVIS is a direct push penetrometer mounted on a CPT platform. It is equipped 

with a vertically mounted charged-coupled device (CCD), a mirror to reflect a side view of the soil into 

the camera, and a sapphire viewing window (Exhibit 4). The GeoVIS uses light from four light-emitting 

diode (LED) light sources (Xenon lamps) to distribute diffused light evenly across a sapphire viewing 

window, resulting in even reflected light from the soil. The standard GeoVIS optics system provides a 

viewing field of approximately 2 by 3 millimeters and a magnification of 100 when viewed on a standard 

13-inch monitor. Approximately eight unique (non-overlapping) photomicrographs can be collected per 

inch of soil or 96 unique images per foot of video push. All soil photomicrographs are collected using a 

frame capture device and can be saved as bitmap files. The pores between sand and gravel grains and 

contents of the pores (such as dense NAPL, or dense nonaqueous phase liquid [DNAPL]) are generally 

readily observable and easily definable from these soil microphotographs. 
30

Exhibit 4: Schematic of GeoVIS Direct-Push Probe 

3.4.2 Effective Porosity 

Porosity between fine-grained materials is part of total porosity that cannot be observed within the 

photomicrographs; therefore, total porosity cannot be rendered. However, effective porosity as it relates 

to the specific yield of the soil is extracted and quantified since the large pores between granular materials 

can be observed. Pixels of grain and matrix materials are converted to pure white and pixels of pore 

space are converted to pure black. The number of white versus black pixels is used to estimate the 

percent pore space in the photomicrograph. Area percentages calculated from two-dimensional 

photomicrographs can be used to estimate porosity, saturation, and void volumes by the consecutive 

volume slice method. If a sufficient number of compositional determinations of two-dimensional slices 

are conducted on a three-dimensional volume, then the composition of the volume can be reliably 

estimated (Exhibit 5). 

Lense/Focusing System 

CCD Color Video Camera 

White LED

Sapphire Window

 Mirror
31

Exhibit 5: Estimated Soil Porosity (Vadose Zone) from GeoVIS Images 

3.4.3 NAPL Saturation 

Obtaining NAPL saturations is more problematic than processing GeoVIS outputs for porosity. NAPL 

color varies based on the thickness of the NAPL in the pores, the NAPL type, background reflectance, 

pore size, and soil type. Dark, globular DNAPLs are easily rendered, whereas lightly colored fuels and 

diesel are not rendered well. Another problem that may arise is that dark mica or other dark minerals can 

also be misinterpreted as free product; therefore, the percentage of dark minerals must be known before 

images can be processed for free product. It is recommended that images of fluorescing NAPL induced 

by LIF be collected to overcome the highly variable nature of NAPL colors and reflectance under most 

field conditions. After the NAPL areas are obtained from each photomicrograph, the areas can be 

converted to NAPL saturation by dividing the area by the effective porosity average for the push. Exhibit 

6 shows the results of the DNAPL image processing for a soil video profile. Photomicrographs of 

DNAPL droplets are shown on the left. Results of the DNAPL image processing, presented in black and 

white, are shown adjacent to each photograph. Pixel counts as total image area and DNAPL saturation 

results are presented on the right. Saturation results are a percent within the pore space, assuming a 

consistent porosity of 43.1 percent. The photomicrographs and image processing results both show a 

large drop in DNAPL droplet numbers and sized and in DNAPL saturation with depth. 
32

Exhibit 6: Vertical Profile of Soil Photomicrographs with DNAPL Droplets 

The information on this technology was adapted from “Confirmation of CPT Video Microscope Estimates 

of In Situ Soil Porosity and NAPL Saturations” (Sinfield, 2004). 

3.5 ADDITIONAL SITE CHARACTERIZATION ACTIVITIES 

In addition to the continued refinement of a CSM to support the evaluation of vapor intrusion issues at the 

Hartford site, information should also be gathered to support the evaluation of the nature and extent of 

dissolved- and free-phase contamination at depth and in off-site areas. The data available from the 

investigations conducted thus far have focused on the presence or absence of free product immediately 

beneath the Hartford site. Future investigations should also consider the engineering and characterization 

data needed to optimize the proposed remedies for the site. 
33

As a first step in this process, the preliminary CSM should be expanded to include potential source areas 

north, east, and west of the Hartford site. Without any information on these potential source areas, it is 

difficult to provide detailed suggestions on delineation of dissolved-phase hydrocarbons at this time. The 

project team should consider the following activities: 

• Compiling existing data from areas surrounding the Hartford site. 

• Continued piezometer installation and monitoring real-time flow directions and water levels 

using pressure transducers in and around source areas where product recovery and SVE will 

likely be applied. 

• Additional water sampling from small-gauge, multi-level wells both on and off site. Smallgauge wells should be installed with screened intervals within, and below, the identified 

boundaries of the free-phase and dissolved-phase plume to monitor product thicknesses and 

water levels. 

• Additional source term characterization should be conducted such that mass loading can be 

estimated and the fate and transport of petroleum contaminants can be predicted. 

• Fate and transport parameters such as groundwater flow velocities and directions should be 

mapped and calibrated using intrinsic tracers, or existing plume extents and characteristics, 

where possible. 

• Natural attenuation parameters should be added to the set of monitoring parameters for wells 

in the distal fringe and surrounding the contaminant plumes. 

Nested wells are needed throughout these areas for product removal, and monitoring wells should also 

extend to some depth below the plumes for monitoring. 

The well network currently proposed should be augmented with small-gauge wells or temporary 

monitoring points whose locations are optimized based on the work products provided in this report. A 

dynamic approach is suggested to limit project cost and improve performance. As mentioned in the CSM 

portion of this report, there are obvious pathways for contaminant transport that will need to be refined 

and targeted. 
34

4.0 INCORPORATING TRIAD-DRIVEN DYNAMIC WORK STRATEGIES 

The general approach presented by Clayton and in the “Technical Memorandum, Vapor Control System 

Upgrade Design” (Clayton 2004c) and the utility and pipeline investigation is a traditional static or 

phased approach. Tetra Tech suggests that the project team instead consider adopting a dynamic work 

strategy to guide future activities. A dynamic work strategy explains how the decisions will be guided by 

field measurement results and how spatial uncertainties will be identified and addressed as the field 

activities proceed. Ideally, stakeholders build consensus on project objectives and key decisions that are 

based on agreed-on action levels before the new field activities are undertaken. 

For example, if a sampling location is found to contain free product, the dynamic work strategy might 

discuss how its extent will be delineated and what type of data will be used to support delineation. 

Another example might include evaluating how headspace soil gas surveys, VMPs, PneuLog, or GeoVIS 

will be used to optimize treatment system design. Data from these types of evaluations then might be 

used to select specific VMP locations and locations where additional design data should be collected. 

These types of strategies should be laid out using a series of flow charts and diagrams before field crews 

mobilize. 

Tetra Tech understands some of the basic reasons behind the phased approach Clayton proposed. 

However, Tetra Tech believes it is imperative for the project team to clearly state the specific rationale 

that will be used to select when and where various activities will be considered. The rationale should be 

based on a well established CSM and address every aspect of the project design, including installation of 

piezometers, direct-push soil borings, VMPs, soil and ambient air gas samples, full-size wells and 

vacuum monitoring probes. Establishing clear guidelines for decision-making should be the first step in 

the systematic planning process. 

The revised CSM should be developed and used to select the most appropriate set of innovative 

technologies for use at the site. A data management and communication platform that operates in real 

time should be considered. Many three-dimensional data presentation tools are available. A web portal 

with a relational database should also be considered to expedite communication of results. This portal 

will facilitate project decision-making on a real-time basis and swift communication of results to all 

regulators and affected stakeholders. 
35

4.1 SUMMARY OF SUGGESTIONS 

The following summarizes the proposed dynamic work strategy to support the implementation of a vapor 

mitigation program and product removal design effort at the Hartford site. The activities are designed in a 

logical sequence such that the quality and utility of data that are collected is maximized. Maximizing the 

utility of data will also require that the CSM for the Hartford site be continually revised as new data are 

received. The CSM can communicate results to stakeholders as new data are received and can guide 

subsequent actions. The CSM should be used as the basis to scope additional work and establish 

contingencies and options that might need to be built into the removal strategy. 

Suggested activities include, but are not necessarily limited to, the following: 

• Hydrocarbon concentrations in near-surface preferential pathways such as sewers and utility 

corridors should be analyzed using ambient air methods. These data are particularly 

important because of the difficulty in using intrusive sampling methods near utility corridors, 

such as Rand Avenue. Real-time ambient air monitoring technologies for sampling from 

sewer manholes are the most promising method. A portable gas chromatograph or the 

equivalent with a mass selective detection system are suggested. 

• The well network should be expanded north, east, and west to answer not only vapor-related 

issues, but also more long-range concerns related to impacts from the Hartford site to the 

surrounding environment. Downhole transducers should be placed in wells as practicable so 

that rapid fluctuations and changes in direction of flow can be monitored on a real-time basis. 

Upgradient sources will likely need to be addressed to assure the long-term effectiveness of 

the remedy. Technologies should be used that can increase well and screened interval 

density. Small gauge multiport wells, such as can be obtained from Precision Sampling Inc., 

should be used to reduce costs and improve the project team’s ability to monitor vertical and 

horizontal off-site migration of contaminants. 

• In addition to lithologic descriptions, any contaminant-related features such as odor, staining, 

or unusual solid constituents should be noted on the logs. The visual observation of 

hydrocarbon contamination should be documented using the following standardized 

descriptions: 

- No Visible Evidence – No visible evidence of oil on soil sample; 

- Sheen – Any visible sheen in the water on soil particles as described by the sheen testing 

method presented later in this section; 

- Staining – Visible brown or black staining in soil. Can be visible as mottling or in bands. 

Typically associated with fine-grained soils; 

- Coating – Visible brown or black oil coating soil particles. Typically associated with 

coarse-grained soils such as coarse sand, gravels, and cobbles; 
36

- Oil Wetted – Visible brown or black oil wetting the soil sample. Oil appears as a liquid 

and is not held by soil grains. Soils oozing petroleum typically contain 2 to 3 percent 

petroleum. 

• These descriptions are general and may need to be modified to more accurately reflect actual 

site conditions and product characteristics. 

• In addition to PID headspace and visual observations, the presence of free product in soil 

cores should also be evaluated periodically through direct application of a technology similar 

to ROST on the open core at ground surface. This evaluation is particularly important across 

the smear zone within the top of the Main Sand, where free product is most likely to be 

present. As the visual evidence of free product decreases, a water sheen test or SiteLAB total 

petroleum hydrocarbon ultraviolet fluorescence (UVF) field test kits or the equivalent might 

be considered to further understand the relationship between the measured concentration in 

soil, the presence of free product, and the ROST response. 

• The water sheen test can be performed by placing soil in a small plastic bag or glass jar, 

adding distilled water, shaking the bag or jar, and observing the water’s surface for signs of 

sheen. Sheen should be classified as follows: 

- No Sheen (NS) – No visible sheen on water surface; 

- Slight Sheen (SS) – Light colorless film; spotty to globular; spread is irregular, not rapid; 

areas of no sheen on water surface remain; film dissipates rapidly; 

- Moderate Sheen (MS) – Light to heavy film; may have some color or iridescence; 

globular to stringy; spread is irregular to flowing; few remaining areas of no sheen on 

water surface; 

- Heavy Sheen (HS) – Heavy colorful film with iridescence; stringy in appearance; spread 

is rapid; sheen flows of the sample; most of water surface may be covered with sheen. 

- Additional multiport VMP and well designs should be optimized using PneuLog. 

Petroleum vapors invading sewer lines should be collected before the final SVE system is 

designed and tested. Specific areas for testing should be identified through the use of the 

CSM as it is revised based on the products developed during this effort and subsequent 

data collection efforts. 

• A near-surface monitoring network that might rely on VMP data and or headspace soil gas 

should be used to evaluate the impact of free product removal and vadose zone SVE or other 

methods for reducing vapors during remedy testing and before full-scale implementation. 

The performance of the system should be checked against well-defined decision criteria 

before full-scale implementation is considered. 

• GeoVIS should be used along with other types of physical and empirical testing to evaluate 

and map zones beneath the village where product removal should be considered. This type of 

evaluation will improve the potential for the effective removal of product beneath the village. 
37

4.2 SUMMARY 

The work products generated in support of the refinement of a CSM for the Hartford site are encouraging. 

Tetra Tech hopes that the additional work products provided in this report will continue to expand the 

project team’s understanding of the Hartford site. Tetra Tech also hopes that the project team will 

continue to refine and clearly state the decision logic that guides the activities in future work plans. The 

project schedule should be sequenced to assure that field activities and remedial efforts are optimized. 

Once optimized, locations where actions will be considered should be further tested using empirical 

methods. As systems come on line, the HWG should continue to refine operating conditions and 

parameters. 

The Hartford site is complex, and implementation of an efficient remedy can be supported by all elements 

of the Triad approach. Real-time measurement techniques can be used to make maximum use of data as 

it is collected. The aggressive use of a systematic plan designed around the refinement of the CSM and 

efficient communication of results is needed. Well-documented dynamic work strategies, which clearly 

define how data will be used to support decision-making, will limit project delays. The collaborative use 

of differing sources of information is needed to improve project efficiency. 

Current data are not sufficient to address many of the principal study questions for the project. As the 

project progresses, Tetra Tech suggests that the project team begin to consider ways to address as many of 

the objectives as efficiently as possible through a dynamic approach designed around innovative 

technologies and strategies. 

Tetra Tech would be pleased to provide related available data sources on the products presented in this 

report to the Hartford Working Group. If you have any questions or comments on this document, please 

contact Mr. Robert A. Howe at (303) 441-7911 or via e-mail at Robert.Howe@ttemi.com. 
38

5.0 REFERENCES 

Clayton Group Services, Inc. 2004a. “Investigation Plan to Define the Extent of Free Phase and 

Dissolved Phase Hydrocarbons in the Village of Hartford, Illinois.” Prepared for The Hartford 

Working Group. January 7. 

Clayton Group Services, Inc. 2004b. “FPH CPT/ROST Subsurface Investigation Report and FPH 

Monitoring Well and Soil Sampling Plan for the Village of Hartford, Illinois.” April 8. 

Clayton Group Services, Inc. 2004c. “Technical Memorandum Vapor Control System Upgrade Design.” 

May 6. 

Clayton Group Services, Inc. 2004d. “Work Plan-Dissolved Phase Groundwater Investigation, The 

Hartford Area Hydrocarbon Plume Site.” June. 

Clayton Group Services, Inc. 2004e. “Letter to USEPA Region 5. Response to Comments to ROST 

Investigation Report and Work Plan.” June 21. 

Clayton Group Services, Inc. 2004f. “Utility and Pipeline Investigation Work Plan, The Hartford Area 

Hydrocarbon Plume Site.” June 29. 

Clayton Group Services, Inc. 2006a. “Dissolved Phase Groundwater Investigation Report.” Prepared for 

The Hartford Working Group. January 4. 

Clayton Group Services, Inc. 2006b. “Site Wide Free Product Investigation.” Prepared for The Premcor 

Refining Group, Inc. January 23. 

Clayton Group Services, Inc. 2006c. “Proposal for an Active LNAPL Recovery System.” Prepared for 

the Hartford Working Group. February 2. 

EPA. 1998. “Innovative Site Remediation Technology, Design and Application.” Volume 7. Vacuum 

Extraction and Air Sparging. 542-B-97-010. May. 

Reading, H.G. (editor). 1996. “Sedimentary Environments: Processes, Facies, and Stratigraphy.” Third 

edition. 

Sinfield, L.S., T. Latas, and W.E. Collins. 2004 “Confirmation of CPT Video Microscope Estimates of 

In Situ Soil Porosity and NAPL Saturations.” 

Tetra Tech EM Inc. (Tetra Tech). 2004. Robert Howe’s personal communication with Bill Davis 

regarding available technology. Tricorder Inc. July. 
FIGURES 
HARTFORD AREA HYDROCARBON PLUME SITE

HARTFORD, ILLINOIS

0 1.5

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Hartford Area

Hydrocarbon

Plume Site

[_

Iowa

Illinois

Missouri

Indiana

Kentucky

Locator Map

Site Boundary μ FIGURE 1

LOCATION MAP



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HROST-98

HROST-61

HROST-10

HROST-79

HROST-62

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HROST-76

HROST-20

HROST-35

HROST-17

HROST-27

HROST-57

HROST-56

HROST-55

HROST-23

HROST-16

HROST-15

HROST-22

HROST-47

HROST-40

HROST-33

HROST-26

HROST-112

HROST-111

HROST-110

HROST-109 HROST-107

HROST-104

HROST-101

HROST-13a

HROST-13

HROST-12

HROST-91

HROST-90

HROST-88

HROST-99

HROST-77

HROST-72

HROST-70

HROST-67

HROST-11

HROST-65

HROST-60

HROST-28

HROST-78

HROST-74

HROST-68

HROST-66

HROST-53

HROST-14

HROST-25

HROST-24

HROST-41

HROST-34

HROST-54

HROST-48

HROST-43

HROST-36

HROST-29

HROST-19

HROST-51

HROST-50

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HROST-37 HROST-39

HROST-30

HROST-115

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HROST-129

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HROST-122

HROST-124 HROST-123

HROST-117 HROST-116 HROST-114

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HROST-31a

0 400

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07/24/07 O:\DOJ\FigA5_Plume.mxd TtEMI-DN Kurt.Cholak

ROST Response Boundary

Pond

Railroad

Parcel

Extent of Free Product Plume

Building

P ROST Sample Location

Building with Reported Fire

μ

HARTFORD AREA HYDROCARBON PLUME SITE

HARTFORD, ILLINOIS

FIGURE 5

ROST APPROXIMATE

EXTENT OF HYDROCARBON MAP
HARTFORD AREA

HYDROCARBON PLUME SITE

HARTFORD, ILLINOIS

FIGURE 6

AVULSION OF A SEDIMENTARY SEQUENCE
HARTFORD AREA

HYDROCARBON PLUME SITE

HARTFORD, ILLINOIS

FIGURE 7

CROSS SECTION OF A MIXED LOAD RIVER
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W. HAWTHORNE STREET

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W. BIRCH ST

N. DELMAR AVENUE

W. CHERRY ST

W. DATE ST

E. BIRCH ST

E. CHERRY ST

E. DATE ST

W. MAPLE STREET E. MAPLE STREET

E. HAWTHORNE STREET

W. WATKINS ST E. WATKINS ST

W. FOREST ST E. FOREST ST

W. ELM ST E. ELM ST

N. OLIVE STREET

W. 1ST STREET E 1ST STREET

N. MARKET STREET

W. ARBOR ST

N. DELMAR AVENUE

E. RAND AVE

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0 400

Feet

Legend

ROST Sample Location

Contour of Thickness of A-Clay above North Olive (feet - depth from surface)

Parcel

Pond

Railroad Building

2007-07-24 O:\DOJ\FigA8_TopA_Clay.mxd TtEMI-DN Kurt.Cholak

Extent of Rand Sand

Contour of Thickness of A-Clay above Main (feet - depth from surface)

Pinched-out Boundary for North Olive

Building with Reported Fire

H

NOTES: 1. Geology referenced from Clayton Group Services April 8, 2004 "FPH 

 CPT/ROST Subsurface Investigation Report and FPH Monitoring 

 Well and Soil Sampling Plan for the Village of Hartford, Illinois".

 2. Main contour is depicted for area where Main Sand is the uppermost

 sand unit. Contour also serves as isopach of silty clay above Main Sand.

A! HMW Well

Contour of Thickness of A-Clay above Rand (feet - depth from surface)

HARTFORD AREA HYDROCARBON PLUME SITE

HARTFORD, ILLINOIS

ISOPACH OF A-CLAY ABOVE

STRATUMS INDICATED

μ

FIGURE 8
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A!

A!

A!

W. HAWTHORNE STREET

ILLINOIS STATE ROUTE 3

W. RAND AVE

OLD ST. LOUIS AND ALTON ROAD

N. OLIVE STREET

W. BIRCH ST

N. DELMAR AVENUE

W. CHERRY ST

W. DATE ST

E. BIRCH ST

E. CHERRY ST

E. DATE ST

W. MAPLE STREET E. MAPLE STREET

E. HAWTHORNE STREET

W. WATKINS ST E. WATKINS ST

W. FOREST ST E. FOREST ST

W. ELM ST E. ELM ST

N. OLIVE STREET

W. 1ST STREET E 1ST STREET

N. MARKET STREET

W. ARBOR ST

N. DELMAR AVENUE

E. RAND AVE

2

2

2

0

6

4

4

4

4

4

4

8

10

2

HMW-27

HMW-26

HMW-25

HROST-7

HROST-8

HROST-1 HROST-2

HROST-5

HROST-3

HROST-6

HROST-52

HROST-13

HROST-12

HROST-91

HROST-88

HROST-85

HROST-84

HROST-83

HROST-89

HROST-92

HROST-93

HROST-94

HROST-96

HROST-97

HROST-98

HROST-99

HROST-61

HROST-10

HROST-79

HROST-77

HROST-72 HROST-70

HROST-67

HROST-62

HROST-80

HROST-76

HROST-11

HROST-65

HROST-60

HROST-20

HROST-28

HROST-74

HROST-35

HROST-68

HROST-66

HROST-53

HROST-14

HROST-25

HROST-24

HROST-17

HROST-41

HROST-34

HROST-27

HROST-57

HROST-56

HROST-55

HROST-54

HROST-48

HROST-43

HROST-36

HROST-23

HROST-19 HROST-16

HROST-15

HROST-22

HROST-51 HROST-50 HROST-49

HROST-47

HROST-45

HROST-44

HROST-40

HROST-39

HROST-37

HROST-33

HROST-30

HROST-26

HROST-115

HROST-118

HROST-128

HROST-126

HROST-130

HROST-125

HROST-122

HROST-124

HROST-123

HROST-112

HROST-110 HROST-111

HROST-109

HROST-107 HROST-106

HROST-104

HROST-101

HROST-13a

HROST-38a

HROST-31a

HROST-90

HROST-87

HROST-78

HROST-29

HROST-129

HROST-117

HROST-116

HROST-114

HROST-103

HROST-49a

0 400

Feet

Legend

ROST Sample Location

North Olive Thickness (feet)

Parcel

Pond

Railroad

Building

2007-07-24 O:\DOJ\FigA9_N_Olive_Sand_Isopach.mxd TtEMI-DN Kurt.Cholak

Building with Reported Fire

H

NOTE: Geology referenced from Clayton Group Services April 8, 2004 "FPH 

 CPT/ROST Subsurface Investigation Report and FPH Monitoring 

 Well and Soil Sampling Plan for the Village of Hartford, Illinois".

A! HMW Well μ

HARTFORD AREA HYDROCARBON PLUME SITE

HARTFORD, ILLINOIS

NORTH OLIVE STRATUM ISOPACH

FIGURE 9
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P

A!

A!

A!

W. HAWTHORNE STREET

ILLINOIS STATE ROUTE 3

W. RAND AVE

OLD ST. LOUIS AND ALTON ROAD

N. OLIVE STREET

W. BIRCH ST

N. DELMAR AVENUE

W. CHERRY ST

W. DATE ST

E. BIRCH ST

E. CHERRY ST

E. DATE ST

W. MAPLE STREET E. MAPLE STREET

E. HAWTHORNE STREET

W. WATKINS ST E. WATKINS ST

W. FOREST ST E. FOREST ST

W. ELM ST E. ELM ST

N. OLIVE STREET

W. 1ST STREET E. 1ST STREET

N. MARKET STREET

S

W. ARBOR ST

N. DELMAR AVENUE

E. RAND AVE

18

18

18

16

16

16

20

20

20

20

14

14

22

22

22

22

12

24

18

18

18

20

20

14

20

14

14

14

16

16

16

12

12

12

12

10

22

20

24

24

26 28

30

32

16

18

24

26

30

28

HMW-26

HMW-27

HMW-25

HROST-8

HROST-2

HROST-5

HROST-3

HROST-91

HROST-87 HROST-88

HROST-85

HROST-84

HROST-81

HROST-83

HROST-89

HROST-93

HROST-94

HROST-96

HROST-97

HROST-98

HROST-61

HROST-10

HROST-79

HROST-72

HROST-62

HROST-80

HROST-76

HROST-65

HROST-20

HROST-68

HROST-17

HROST-41

HROST-27

HROST-57

HROST-55

HROST-54

HROST-19

HROST-15

HROST-22

HROST-47

HROST-30

HROST-26

HROST-118

HROST-126

HROST-114

HROST-112

HROST-101

HROST-13a

HROST-7

HROST-1

HROST-6

HROST-52

HROST-13

HROST-12

HROST-90

HROST-92

HROST-99

HROST-77

HROST-70

HROST-67

HROST-11

HROST-60

HROST-28

HROST-78

HROST-74

HROST-35

HROST-66

HROST-53

HROST-14

HROST-25

HROST-24

HROST-34

HROST-56

HROST-48

HROST-43

HROST-36

HROST-29

HROST-23

HROST-16

HROST-51

HROST-50

HROST-49

HROST-45

HROST-44

HROST-40

HROST-39

HROST-37

HROST-33

HROST-115

HROST-129

HROST-128

HROST-130

HROST-125

HROST-122

HROST-124

HROST-123

HROST-117

HROST-116

HROST-111

HROST-110

HROST-109

HROST-107

HROST-106

HROST-104

HROST-103

HROST-49a

HROST-38a

HROST-31a

0 400

Feet

Legend

2007-07-24 O:\DOJ\FigA10_Rand_Sand_Top.mxd TtEMI-DN Kurt.Cholak

NOTE: Geology referenced from Clayton Group Services April 8, 2004 "FPH 

 CPT/ROST Subsurface Investigation Report and FPH Monitoring 

 Well and Soil Sampling Plan for the Village of Hartford, Illinois".

H ROST Sample Location

A! HMW Well

Rand Contour (feet - depth from surface)

Main Contour (feet - depth from surface)

Pinched-out Boundary for Rand

Boundary of Rand Conjoining Main

Pond

Railroad

Parcel

Building

Building with Reported Fire

μ

HARTFORD AREA HYDROCARBON PLUME SITE

HARTFORD, ILLINOIS

TOP OF RAND AND

MAIN STRATUM

FIGURE 10
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A!

A!

A!

W. HAWTHORNE STREET

ILLINOIS STATE ROUTE 3

W. RAND AVE

OLD ST. LOUIS AND ALTON ROAD

N. OLIVE STREET

W. BIRCH ST

N. DELMAR AVENUE

W. CHERRY ST

W. DATE ST

E. BIRCH ST

E. CHERRY ST

E. DATE ST

W. MAPLE STREET E. MAPLE STREET

E. HAWTHORNE STREET

W. WATKINS ST E. WATKINS ST

W. FOREST ST E. FOREST ST

W. ELM ST E. ELM ST

N. OLIVE STREET

W. 1ST STREET E 1ST STREET

N. MARKET STREET

W. ARBOR ST

N. DELMAR AVENUE

E. RAND AVE

4

4

4

2

2

2

6

6

8

8

1

0

10

12

0

0

0

0

4

2

0

2

HROST-7

HROST-8

HROST-1

HROST-2

HROST-6

HROST-52

HROST-13

HROST-90

HROST-87 HROST-88

HROST-85

HROST-84

HROST-83

HROST-89

HROST-92

HROST-93

HROST-94

HROST-96

HROST-97

HROST-98

HROST-99

HROST-61

HROST-77

HROST-72 HROST-70

HROST-67

HROST-62

HROST-76

HROST-11

HROST-65

HROST-60

HROST-20

HROST-28

HROST-74

HROST-35

HROST-68

HROST-66

HROST-53

HROST-14

HROST-25

HROST-17

HROST-41

HROST-34

HROST-27

HROST-57

HROST-56

HROST-55

HROST-54

HROST-48

HROST-43

HROST-36

HROST-15

HROST-22

HROST-51

HROST-50

HROST-49

HROST-45

HROST-44

HROST-37

HROST-30 HROST-33

HROST-26

HROST-115

HROST-118

HROST-126

HROST-124

HROST-112

HROST-110 HROST-111

HROST-109

HROST-107

HROST-106

HROST-104

HROST-103

HROST-101

HROST-49a

HROST-5

HROST-3

HROST-12

HROST-91

HROST-10

HROST-79

HROST-80

HROST-78

HROST-24

HROST-29

HROST-23

HROST-16

HROST-19

HROST-47

HROST-40

HROST-39

HROST-129

HROST-128

HROST-130

HROST-125

HROST-122

HROST-123

HROST-117

HROST-116

HROST-114

HROST-13a

HROST-38a

HROST-31a

HMW-27

HMW-26

HMW-25

0 400

Feet

Legend

2007-07-24 O:\DOJ\FigA11_Rand_Sand_Isopach.mxd TtEMI-DN Kurt.Cholak

NOTE: Geology referenced from Clayton Group Services April 8, 2004 "FPH 

 CPT/ROST Subsurface Investigation Report and FPH Monitoring 

 Well and Soil Sampling Plan for the Village of Hartford, Illinois".

A! HMW Well

Pond

Railroad

Parcel

Building

H ROST Sample Location

Thickness of Rand in feet

Building with Reported Fire

μ

HARTFORD AREA HYDROCARBON PLUME SITE

HARTFORD, ILLINOIS

THICKNESS OF RAND

STRATUM IN FEET

FIGURE 11
A!

A!

A!

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P

W. HAWTHORNE STREET

ILLINOIS STATE ROUTE 3

W. RAND AVE

OLD ST. LOUIS AND ALTON ROAD

N. OLIVE STREET

W. BIRCH ST

N. DELMAR AVENUE

W. CHERRY ST

W. DATE ST

E. BIRCH ST

E. CHERRY ST

E. DATE ST

W. MAPLE STREET E. MAPLE STREET

E. HAWTHORNE STREET

W. WATKINS ST E. WATKINS ST

W. FOREST ST E. FOREST ST

W. ELM ST E. ELM ST

N. OLIVE STREET

W. 1ST STREET E 1ST STREET

N. MARKET STREET

W. ARBOR ST

N. DELMAR AVENUE

E. RAND AVE

6

4

8

2

10

16

18 20

4

14

10

8

16

6

8

12

12

14

18

20

14 12 10

24

22

20

16

18

14

4

2

10

16

20

18

12

16

HROST-7

HROST-8

HROST-1

HROST-2

HROST-5

HROST-3

HROST-6

HROST-52

HROST-13

HROST-12

HROST-91 HROST-87 HROST-88

HROST-85

HROST-84

HROST-83

HROST-89

HROST-92

HROST-93

HROST-94

HROST-96

HROST-97

HROST-98 HROST-99

HROST-61

HROST-10

HROST-79

HROST-77

HROST-72 HROST-70

HROST-67

HROST-62

HROST-80

HROST-76

HROST-11

HROST-65

HROST-60

HROST-20

HROST-28

HROST-74

HROST-35

HROST-68

HROST-66

HROST-53

HROST-14

HROST-25

HROST-24

HROST-17

HROST-41

HROST-34

HROST-27

HROST-57

HROST-56

HROST-55

HROST-54

HROST-48

HROST-43

HROST-36

HROST-23

HROST-16 HROST-19

HROST-15

HROST-22

HROST-50 HROST-51

HROST-49

HROST-47

HROST-44 HROST-45

HROST-40

HROST-39

HROST-37

HROST-33

HROST-30

HROST-26

HROST-115

HROST-118

HROST-128

HROST-126

HROST-130

HROST-125

HROST-122

HROST-124

HROST-123

HROST-111 HROST-112

HROST-110

HROST-109

HROST-107

HROST-106

HROST-104

HROST-103

HROST-101

HROST-13a

HROST-49a

HROST-38a

HROST-31a

HROST-90

HROST-78HROST-29

HROST-129

HROST-117

HROST-116

HROST-114

HMW-27

HMW-26

HMW-25

0 400

Feet

Legend

Building

2007-07-24 O:\DOJ\FigA12_isopach_clay_above_rand.mxd TtEMI-DN Kurt.Cholak

Building with Reported Fire

NOTE: Geology referenced from Clayton Group Services April 8, 2004 "FPH 

 CPT/ROST Subsurface Investigation Report and FPH Monitoring 

 Well and Soil Sampling Plan for the Village of Hartford, Illinois".

H ROST Sample Location

Isopach Silty Clay Contour in feet

Extent of Rand Sand

Pinched-out Boundary for North Olive

Pond

Railroad

Parcel

A! HMW Well

Isopach Silty Clay Contour above Main in feet μ

HARTFORD AREA HYDROCARBON PLUME SITE

HARTFORD, ILLINOIS

ISOPACH OF SILTY CLAY BETWEEN

RAND STRATUM OR MAIN SAND

AND THE NORTH OLIVE STRATUM

OR GROUND SURFACE

FIGURE 12
A!

A!

A!

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P

W. HAWTHORNE STREET

ILLINOIS STATE ROUTE 3

W. RAND AVE

OLD ST. LOUIS AND ALTON ROAD

N. OLIVE STREET

W. BIRCH ST

N. DELMAR AVENUE

W. CHERRY ST

W. DATE ST

E. BIRCH ST

E. CHERRY ST

E. DATE ST

W. MAPLE STREET E. MAPLE STREET

E. HAWTHORNE STREET

W. WATKINS ST E. WATKINS ST

W. FOREST ST E. FOREST ST

W. ELM ST E. ELM ST

N. OLIVE STREET

W. 1ST STREET E 1ST STREET

N. MARKET STREET

W. ARBOR ST

N. DELMAR AVENUE

E. RAND AVE

32

32

30

30

30

28

34

36

18

18

24

22 20

26

26

28

28

28

16

16

1

1

4

4

14

12

12

12

12

30

30

30

30

32

32

32

10

34

20

18

16

14

HROST-31a

HROST-38a

HROST-49a

HROST-103

HROST-104

HROST-106

HROST-107

HROST-111

HROST-114

HROST-116

HROST-117

HROST-123 HROST-124

HROST-122

HROST-125

HROST-126

HROST-128

HROST-129

HROST-118

HROST-115

HROST-30

HROST-37 HROST-39

HROST-40

HROST-44

HROST-45

HROST-49

HROST-50

HROST-51

HROST-15

HROST-16

HROST-23

HROST-29

HROST-36

HROST-43

HROST-48

HROST-54

HROST-27

HROST-17

HROST-24

HROST-25

HROST-14

HROST-53

HROST-68

HROST-35

HROST-74

HROST-78

HROST-28

HROST-20

HROST-60

HROST-65

HROST-11

HROST-67

HROST-72 HROST-70

HROST-77

HROST-79

HROST-87

HROST-90

HROST-91

HROST-12

HROST-52

HROST-3

HROST-8

HROST-7

HROST-13a

HROST-101

HROST-109

HROST-110 HROST-112

HROST-130

HROST-26

HROST-33

HROST-47

HROST-22

HROST-19

HROST-55

HROST-56

HROST-57

HROST-34

HROST-41

HROST-66

HROST-76

HROST-80

HROST-62

HROST-10

HROST-61

HROST-99

HROST-98

HROST-97

HROST-96

HROST-94

HROST-93

HROST-92

HROST-89

HROST-83

HROST 81

HROST-84

HROST-85

HROST-88

HROST-13

HROST-6 HROST-5

HROST-2 HROST-1

HMW-25

HMW-26

HMW-27

0 400

Feet

Legend

2007-07-24 O:\DOJ\FigA13_Epa_Sand_Top.mxd TtEMI-DN Kurt.Cholak

NOTE: Geology referenced from Clayton Group Services April 8, 2004 "FPH 

 CPT/ROST Subsurface Investigation Report and FPH Monitoring 

 Well and Soil Sampling Plan for the Village of Hartford, Illinois".

EPA Contour (feet - depth from surface)

Pond

Railroad

Parcel

Building

Main Contour (feet - depth from surface)

A! HMW Well

H ROST Sample Location

Building with Reported Fire

μ

HARTFORD AREA HYDROCARBON PLUME SITE

HARTFORD, ILLINOIS

TOP OF EPA STRATUM

FIGURE 13
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A!

A!

A!

W. HAWTHORNE STREET

ILLINOIS STATE ROUTE 3

W. RAND AVE

OLD ST. LOUIS AND ALTON ROAD

N. OLIVE STREET

W. BIRCH ST

N. DELMAR AVENUE

W. CHERRY ST

W. DATE ST

E. BIRCH ST

E. CHERRY ST

E. DATE ST

W. MAPLE STREET E. MAPLE STREET

E. HAWTHORNE STREET

W. WATKINS ST E. WATKINS ST

W. FOREST ST E. FOREST ST

W. ELM ST E. ELM ST

N. OLIVE STREET

N. MARKET STREET

W. ARBOR ST

N. DELMAR AVENUE

E. RAND AVE

HROST-49a

HROST-116 HROST-114 HROST-117

HROST-125

HROST-130

HROST-129

HROST-118

HROST-29

HROST-78

HROST-61

HROST-88

HROST-90 HROST-91

HROST-3

HROST-5

HROST-2

HROST-31a

HROST-38a

HROST-13a

HROST-101

HROST-103

HROST-104

HROST-106

HROST-107

HROST-109

HROST-110 HROST-111 HROST-112

HROST-123

HROST-124

HROST-122

HROST-126

HROST-128

HROST-115

HROST-26

HROST-30 HROST-33

HROST-37

HROST-39

HROST-40

HROST-44

HROST-45

HROST-47

HROST-49

HROST-50

HROST-51

HROST-22

HROST-15

HROST-19

HROST-16

HROST-23

HROST-36

HROST-43

HROST-48

HROST-54

HROST-55

HROST-56

HROST-27

HROST-34

HROST-41

HROST-17

HROST-24

HROST-25

HROST-14

HROST-53

HROST-66

HROST-68

HROST-35

HROST-74

HROST-28

HROST-20

HROST-60

HROST-65

HROST-11

HROST-76

HROST-80

HROST-62

HROST-67

HROST-70

HROST-72

HROST-77

HROST-79

HROST-10

HROST-99

HROST-98

HROST-97

HROST-96

HROST-94

HROST-93

HROST-92

HROST-89

HROST-82

HROST-83

HROST-81

HROST-84

HROST-85

HROST-87

HROST-12

HROST-13

HROST-52

HROST-6

HROST-1

HROST-8

HROST-7

HMW-25

HMW-26

HMW-27

8

8

6

10

0 400

Feet

Legend

2007-07-24 O:\DOJ\FigA14_Epa_Sand_Isopach.mxd TtEMI-DN Kurt.Cholak

NOTE: Geology referenced from Clayton Group Services April 8, 2004 "FPH 

 CPT/ROST Subsurface Investigation Report and FPH Monitoring 

 Well and Soil Sampling Plan for the Village of Hartford, Illinois".

Building

Parcel

Railroad

Pond

EPA Merges with Main Boundary

H ROST Sample Location

Building with Reported Fire

EPA Thickness (Feet) μ

HARTFORD AREA HYDROCARBON PLUME SITE

HARTFORD, ILLINOIS

EPA STRATUM ISOPACH

FIGURE 14
P

P

P P

P P P P

P

P

P

PP P P

P

P

P

P

P

P

P

P

P

P

P

P

P

P

P

P

P

P

P

P

P

P

P

P

P

P

P

P

P

P

P P

P P

P

P

P

P

P

P

P

P

P P

P

P

P

P

P

P

P

P

P

P

P P P

P P P P P

P

P

P

P

P

P

P

P

P

P

P

P P

P

P

P

P

P

P

P P

P

P

P

P P

P

A!

A!

A!

W. HAWTHORNE STREET

ILLINOIS STATE ROUTE 3

W. RAND AVE

OLD ST. LOUIS AND ALTON ROAD

N. OLIVE STREET

W. BIRCH ST

N. DELMAR AVENUE

W. CHERRY ST

W. DATE ST

E. BIRCH ST

E. CHERRY ST

E. DATE ST

W. MAPLE STREET E. MAPLE STREET

E. HAWTHORNE STREET

W. WATKINS ST E. WATKINS ST

W. FOREST ST E. FOREST ST

W. ELM ST E. ELM ST

N. OLIVE STREET

W. 1ST STREET E. 1ST STREET

N. MARKET STREET

W. ARBOR ST

N. DELMAR AVENUE

E. RAND AVE

2

4

6

6

6

8

8

10

12

14

8

10

6

8

4

0

12

14

10

8

6

4

2

4

HROST-7

HROST-8

HROST-1

HROST-6

HROST-52

HROST-13

HROST-12

HROST-87

HROST-85

HROST-84

HROST-83

HROST-89

HROST-92

HROST-93

HROST-94

HROST-96

HROST-97

HROST-98

HROST-99

HROST-10

HROST-79

HROST-77

HROST-72

HROST-70

HROST-67

HROST-62

HROST-80

HROST-76 HROST-11

HROST-65

HROST-60

HROST-20

HROST-28

HROST-74

HROST-35

HROST-68

HROST-66

HROST-53

HROST-14

HROST-25

HROST-24

HROST-17

HROST-41

HROST-34

HROST-27

HROST-57

HROST-56

HROST-55

HROST-54

HROST-48

HROST-43

HROST-36

HROST-23

HROST-16

HROST-19

HROST-15

HROST-22

HROST-51

HROST-50

HROST-49

HROST-47

HROST-45

HROST-44

HROST-40

HROST-39

HROST-37

HROST-33 HROST-30

HROST-26

HROST-115

HROST-128

HROST-126

HROST-122

HROST-124

HROST-123

HROST-112 HROST-110 HROST-111

HROST-109 HROST-107

HROST-106

HROST-104

HROST-103

HROST-101

HROST-13a

HROST-38a

HROST-31a

HROST-2

HROST-5

HROST-3

HROST-90 HROST-91

HROST-88

HROST-61

HROST-78

HROST-29

HROST-118

HROST-129

HROST-130

HROST-125

HROST-117 HROST-116 HROST-114

HROST-49a

HMW-27

HMW-26

HMW-25

0 400

Feet

Legend

Building

2007-07-24 O:\DOJ\FigA15_Silty_Clay_above_EPA.mxd TtEMI-DN Kurt.Cholak

Building with Reported Fire

NOTE: Geology referenced from Clayton Group Services April 8, 2004 "FPH 

 CPT/ROST Subsurface Investigation Report and FPH Monitoring 

 Well and Soil Sampling Plan for the Village of Hartford, Illinois".

Pond

Railroad

Parcel

H ROST Sample Location

A! HMW Well

Silty Clay Thickness (feet)

Extent of EPA Sand μ

HARTFORD AREA HYDROCARBON PLUME SITE

HARTFORD, ILLINOIS

ISOPACH OF SILTY CLAY BETWEEN

EPA STRATUM OR MAIN SAND AND

THE RAND STRATUM OR NORTH

OLIVE STRATUM

FIGURE 15
A!

A!

A!

P

P

P P

P P P P

P

P

P

PP P P

P

P

P

P

P

P

P

P

P

P

P

P

P

P

P

P

P

P

P

P

P

P

P

P

P

P

P

P

P

P

P P

P P

P

P

P

P

P

P

P

P

P P

P

P

P

P

P

P

P

P

P

P

P P P

P P P P P

P

P

P

P

P

P

P

P

P

P

P

P

P P

P

P

P

P

P

P

P P

P

P

P

P P

P

W. HAWTHORNE STREET

ILLINOIS STATE ROUTE 3

W. RAND AVE

OLD ST. LOUIS AND ALTON ROAD

N. OLIVE STREET

W. BIRCH ST

N. DELMAR AVENUE

W. CHERRY ST

W. DATE ST

E. BIRCH ST

E. CHERRY ST

E. DATE ST

W. MAPLE STREET E. MAPLE STREET

E. HAWTHORNE STREET

W. WATKINS ST E. WATKINS ST

W. FOREST ST E. FOREST ST

W. ELM ST E. ELM ST

N. OLIVE STREET

W. 1ST STREET E 1ST STREET

N. MARKET STREET

W. ARBOR ST

N. DELMAR AVENUE

E. RAND AVE

HROST-1

HROST-2

HROST-5 HROST-6

HROST-13

HROST-88

HROST-85

HROST-84

HROST-83

HROST-89

HROST-92

HROST-93

HROST-94

HROST-96

HROST-97

HROST-98

HROST-99

HROST-61

HROST-10

HROST-62

HROST-80

HROST-76

HROST-66

HROST-41

HROST-34

HROST-57

HROST-56

HROST-55

HROST-19

HROST-22

HROST-47

HROST-33

HROST-26

HROST-130

HROST-112

HROST-110

HROST-109

HROST-101

HROST-13a

HROST-7

HROST-8

HROST-3

HROST-52

HROST-12

HROST-91

HROST-90

HROST-87

HROST-79

HROST-77

HROST-72

HROST-70

HROST-67

HROST-11

HROST-65

HROST-60

HROST-20

HROST-28

HROST-78

HROST-74

HROST-35

HROST-68

HROST-53

HROST-14

HROST-25 HROST-24

HROST-17

HROST-27

HROST-54

HROST-48

HROST-43

HROST-36

HROST-29

HROST-23

HROST-16

HROST-15

HROST-51

HROST-50

HROST-49

HROST-45

HROST-44

HROST-40

HROST-39

HROST-37

HROST-30

HROST-115

HROST-118

HROST-129

HROST-128

HROST-126

HROST-125

HROST-122

HROST-124

HROST-123

HROST-117

HROST-116

HROST-114

HROST-111

HROST-107

HROST-106

HROST-104

HROST-103

HROST-49a

HROST-38a

HROST-31a

HMW-27

HMW-26

HMW-25

36

18

38

34

16

40

32

14

42

44

12

46

16

14

18

24

22 20

20

30

30

30

26

26

28

28

14

12

12

12

12

10

32

32

16

14

28

24

16

20

24

20

18

24

20

12

34

36

30

40

30

38

16

0 400

Feet

Legend

2007-07-24 O:\DOJ\FigA16_Main_Sand_Top.mxd TtEMI-DN Kurt.Cholak

NOTE: Geology referenced from Clayton Group Services April 8, 2004 "FPH 

 CPT/ROST Subsurface Investigation Report and FPH Monitoring 

 Well and Soil Sampling Plan for the Village of Hartford, Illinois".

Pond

Railroad

Parcel

Building

A! HMW Well

H ROST Sample Location

Main Contour in feet

Building with Reported Fire

μ

HARTFORD AREA HYDROCARBON PLUME SITE

HARTFORD, ILLINOIS

TOP OF MAIN SAND

FIGURE 16
D

D

DD D

!(

!(

!( !(

!( !( !( !(

!(

!(

!(

!(!( !( !(

!(

!(

!(

!(

!(

!(

!(

!(

!(

!(

!(

!(

!(

!

!

!

!

!

!

!

!

!

!(

!(

!(

!(

!(

!

!(

!(

! !(

!( !(

!(

!

!

!(

!(

!

!(

!

! !(

!

!(

!(

!(

!

!

!

!

!

!

! ! !

! !( !( !( !(

!(

!

!

!

!

!

!

!

!(

!

!(

!(

!( !(

!(

!(

!(

!( !(

!(

!( !(

!(

!(

!(

!( !(

!(

W. HAWTHORNE STREET

ILLINOIS STATE ROUTE 3

W. RAND AVE

OLD ST. LOUIS AND ALTON ROAD

N. OLIVE STREET

W. BIRCH ST

N. DELMAR AVENUE

W. CHERRY ST

W. DATE ST

E. BIRCH ST

E. CHERRY ST

E. DATE ST

W. MAPLE STREET E. MAPLE STREET

E. HAWTHORNE STREET

W. WATKINS ST E. WATKINS ST

W. FOREST ST E. FOREST ST

W. ELM ST E. ELM ST

N. OLIVE STREET

W. 1ST STREET E 1ST STREET

N. MARKET STREET

W. ARBOR ST

N. DELMAR AVENUE

E. RAND AVE

32

24

20

28

16 12

8

36

4

40

44

48

52

20

40

16

20

8

32

32

24

20

12

36

28

12

32

24

28

28

28

24

8

24

20

16

28

32

24

44

12

4

HROST-7

HROST-8

HROST-1

HROST-5

HROST-3

HROST-6

HROST-52

HROST-13

HROST-12

HROST-91

HROST-87

HROST-88

HROST-85 HROST-83 HROST-84

HROST-89

HROST-92

HROST-93

HROST-94

HROST-96

HROST-97

HROST-98

HROST-99

HROST-61

HROST-10

HROST-79

HROST-77

HROST-72

HROST-70

HROST-67

HROST-62

HROST-80

HROST-76

HROST-11

HROST-65

HROST-60

HROST-20

HROST-28

HROST-74

HROST-35

HROST-68

HROST-66 HROST-53

HROST-14

HROST-25

HROST-24

HROST-17

HROST-41

HROST-34

HROST-27

HROST-57

HROST-56

HROST-55

HROST-54

HROST-48

HROST-43

HROST-36

HROST-23

HROST-16

HROST-19

HROST-15

HROST-22

HROST-50 HROST-51 HROST-49

HROST-47

HROST-45

HROST-44

HROST-40

HROST-39

HROST-37

HROST-33

HROST-30

HROST-26

HROST-118

HROST-130

HROST-124

HROST-117

HROST-114

HROST-112

HROST-110 HROST-111

HROST-109

HROST-107

HROST-106

HROST-104

HROST-103

HROST-101

HROST-13a

HROST-38a

HROST-31a

HROST-2

HROST-90

HROST-78

HROST-29

HROST-115

HROST-129

HROST-128

HROST-126

HROST-125

HROST-122

HROST-123

HROST-116

HROST-49a

0 400

Feet

Legend

2007-07-24 O:\DOJ\FigA17_Total_Product_Top.mxd TtEMI-DN Kurt.Cholak

NOTE: Hydrocarbon thickness and extents referenced from Clayton Group Services

 April 8, 2004 "FPH CPT/ROST Subsurface Investigation Report and FPH

 Monitoring Well and Soil Sampling Plan for the Village of Hartford, Illinois".

Light Range Product Boundary

Mid Range Product Boundary

Heavy Range Product Boundary

Building with Reported Fire

Pond

Railroad

Parcel

! ROST Sample Location - no apparent product

!( ROST Sample Location - Light Range Product

!( ROST Sample Location - Mid Range Product

!( ROST Sample Location - Heavy Range Product

Product Boundary

Product Contour in feet, depth below surface

Building

μ

HARTFORD AREA HYDROCARBON PLUME SITE

HARTFORD, ILLINOIS

TOP OF TOTAL PETROLEUM

HYDROCARBON ROST RESPONSE

FIGURE 17
Legend

2007-07-24 O:\DOJ\FigA18_Product_Thickness_ROST_Responses.mxd TtEMI-DN Kurt.Cholak

D

DD D

W. HAWTHORNE STREET

ILLINOIS STATE ROUTE 3

W. RAND AVE

OLD ST. LOUIS AND ALTON ROAD

N. OLIVE STREET

W. BIRCH ST

N. DELMAR AVENUE

W. CHERRY ST

W. DATE ST

E. BIRCH ST

E. CHERRY ST

E. DATE ST

W. MAPLE STREET E. MAPLE STREET

E. HAWTHORNE STREET

W. WATKINS ST E. WATKINS ST

W. FOREST ST E. FOREST ST

W. ELM ST E. ELM ST

N. OLIVE STREET

N. MARKET STREET

W. ARBOR ST

N. DELMAR AVENUE

E. RAND AVE

NOTE: Geology referenced from Clayton Group Services April 8, 2004 "FPH 

 CPT/ROST Subsurface Investigation Report and FPH Monitoring 

 Well and Soil Sampling Plan for the Village of Hartford, Illinois".

0 200 400

Feet

Pond

Railroad

Parcel

Building

30 to < 40 Feet of total ROST Response

10 to < 20 Feet of total ROST Response

5 to < 10 Feet of total ROST Response

Building with Reported Fire

20 to < 30 Feet of total ROST Response

Sources:

Clayton Group Services, Inc. 2006a.,

Clayton Group Services, Inc. 2004b.,

Clayton Group Services, Inc. 2006c.

Note: < Less Than

HARTFORD AREA HYDROCARBON PLUME SITE

HARTFORD, ILLINOIS

TOTAL PETROLEUM HYDROCARBON

ROST RESPONSE THICKNESS

FIGURE 18

μ
W. HAWTHORNE STREET

ILLINOIS STATE ROUTE 3

W. RAND AVE

OLD ST. LOUIS AND ALTON ROAD

N. OLIVE STREET

W. BIRCH ST

N. DELMAR AVENUE

W. CHERRY ST

W. DATE ST

E. BIRCH ST

E. CHERRY ST

E. DATE ST

W. MAPLE STREET E. MAPLE STREET

E. HAWTHORNE STREET

W. WATKINS ST E. WATKINS ST

W. FOREST ST E. FOREST ST

W. ELM ST E. ELM ST

N. OLIVE STREET

W. 1ST STREET E. 1ST STREET

N. MARKET STREET

W. ARBOR ST

N. DELMAR AVENUE

E. RAND AVE

10

8

8

10

10

12

12

12

12

12

0 400

Feet

Legend

Top of Sand

(feet - depth from surface)

Parcel

Pond

Railroad

Building

2007-07-24 O:\DOJ\FigA19_Sewer_Map.mxd TtEMI-DN Kurt.Cholak

Building with Reported Fire

Product Pipeline

Municipal Sewer

Industrial Sewer

Forced Main

Less than 8 Feet Below Ground Surface

8-10 Feet Below Ground Surface

10-12 Feet Below Ground Surface

HARTFORD AREA HYDROCARBON PLUME SITE

HARTFORD, ILLINOIS

LOCATIONS WHERE POROUS STRATUM

(SAND UNITS) ARE POTENTIALLY IN

CONTACT WITH PRODUCT PIPELINES

AND MUNICIPAL SEWERS

FIGURE 19

μ
Considerations for Applying Office of Solid Waste and EPA-542-R-06-008 

 the Triad Approach Emergency Response August 2007  Hartford Area Hydrocarbon Plume Site www.epa.gov/tio

http://clu-in.org

United States Environmental Protection Agency (5102G) Washington, DC 20460 Official Business Penalty for Private Use $300