Characterizing Natural Attenuation in Groundwater

at a Chlorinated Solvent Contaminated Industrial Site in

Virginia

by

John Robert Maas

A capstone project submitted to the Graduate Faculty of

North Carolina State University

in partial fulfillment of the

requirements for the degree of

Master of Environmental Assessment

Raleigh, North Carolina

2015

Approved by advisory committee:

Committee Chair- Linda Taylor

May 11, 2015

ii

© Copyright 2015 John R. Maas

All Rights Reserved

iii

Abstract

Maas, John R. Master of Environmental Assessment Program. Characterizing Natural

Attenuation in Groundwater at a Chlorinated Solvent Contaminated Industrial Site in Virginia

This case study focuses on the monitored natural attenuation (MNA) of historical

chlorinated solvent releases at an industrial manufacturing facility in Virginia, referred to as the

site. The primary constituent of concern for this study is Trichloroethylene (TCE). The United

States Environmental Protection Agency has classified TCE as carcinogenic to humans. The

areas of impacted groundwater are examined and categorized according to occurrence of the

source product TCE, light and dense non-aqueous phase liquids, TCE breakdown or daughter

products, and geochemical properties. The United States Environmental Protection Agency’s

Technical Protocol for Evaluating Natural Attenuation of Chlorinated Solvents in Ground Water

(EPA/600/R-98/128, 1998) is used as guidance in this study. This document details the EPA's

approach for applying and assessing MNA as a cleanup tool for chlorinated solvents in

groundwater. Monitoring of TCE biodegradation can be a suitable, cost-effective course of

remedial action for a contaminated site. MNA can work as the sole remedial option or with other

more active remedial tools at some sites where biogeochemical conditions favor natural

processes that degrade or immobilize harmful contaminants.

The high concentrations and occurrence of TCE as a dense non-aqueous phase liquid

prohibit the feasibility of MNA as a sole remedial option for the site. However, data collected

indicates that areas of the site are amenable to MNA, and that MNA may be able to play a larger

role when applied in combination with more aggressive clean up action at source areas. This

paper demonstrates that while MNA is an enticing and cost effective remedial alternative,

exclusive reliance on natural attenuation for contaminant degradation is not practical for all sites.

iv

Biography

John Maas, P.G. is a Geologist with Amec Foster Wheeler Environment & Infrastructure,

Inc in Durham, North Carolina. Mr. Maas has practiced environmental consulting in the south

eastern region of the United States since 2010. He has conducted environmental investigations of

sites in North Carolina, South Carolina, and Virginia, and is knowledgeable of both federal and

state regulations. His project involvement consists of conducting Phase I and Phase II

environmental site assessments, soil and groundwater remediation projects, emergency response

activities, risk assessments, and proposal and report writing. Mr. Maas’ field knowledge includes

health and safety coordination; installation and development of groundwater monitoring wells;

subsurface soil, groundwater, and vapor sampling; supervision of probing and drilling operations;

site feature logging utilizing survey and GPS equipment; and coordination of environmental

investigations and remediation.

Mr. Maas’ technical expertise involves risk assessment, contaminant transportation

modelling, use of ArcGIS and geophysical software as well as map, table, and figure creation

through the use of various programs. Mr. Maas has gained unique experience in developing and

applying his technical expertise by performing investigative and remedial activities on sites which

currently or formerly hosted dry cleaning facilities. He was worked with the North Carolina State

Government Dry-Cleaning Solvent Cleanup Act (DSCA) and performed 1% investigations,

preliminary assessments, and remediations. These projects involve identifying and characterizing

chlorinated solvent impacted soils, groundwater contamination plumes, impacted surface waters,

and indoor air and sub slab vapor analyses. Mr. Maas is an accredited asbestos inspector in both

North Carolina and Virginia, and has experience in performing lead-based paint inspections.

John Maas received his Bachelors of Science degree in Geology from North Carolina State

University in Raleigh. As an undergraduate, he conducted research with the Surface Processes and

Active Tectonics Lab under Dr. Karl Wegmann. His undergraduate research project, entitled

“Legacy Sediments and Stream Water Quality: Estimating available Nutrient Content in Richland

Creek, a tributary to Crabtree Creek and the Neuse River”, was presented at the spring 2010

Undergraduate Research Symposium at NCSU. Mr. Maas has also received the rank of Eagle

Scout with the Boy Scouts of America.

v

Acknowledgements

I would first and foremost like to express my most heartfelt gratitude for the love and

support I have received from my wife, Anna. My special thanks to my dogs, Pearl and Theo, for

providing entertainment and much needed mental recess while working on this study. Thanks to

my family for providing encouragement and laughs as each was appropriately called for.

I would like to acknowledge my coworkers Jay Bennett, Bonani Langan, and Anthony

Kellogg for their technical knowledge and assistance in this site assessment. A special thank you

to Amec Foster Wheeler Environment & Infrastructure, Inc. for allowing the use of the data

contained herein and for the flexibility allowing me to complete this study. My sincere thanks to

my colleagues who provided reviews and feedback for my work. Finally, I would like to extend

my thanks to the faculty and staff at NC State, especially to Linda Taylor and Dr. Catherine

LePrevost for their guidance and direction with this project.

vi

Table of Contents

Abstract .......................................................................................................................................... iii

Biography ....................................................................................................................................... iv

Acknowledgements ..........................................................................................................................v

List of Tables ................................................................................................................................ vii

List of Figures ............................................................................................................................... vii

List of Acronyms ......................................................................................................................... viii

Introduction ......................................................................................................................................1

Methods............................................................................................................................................4

Results and Discussion ..................................................................................................................10

Conclusions ....................................................................................................................................16

References ......................................................................................................................................18

Appendix A: Data Tables...............................................................................................................22

vii

List of Tables

Table 1: Analytical Data for Groundwater ....................................................................................23

Table 2a: Groundwater Geochemical Data - Event #1, October 2013 ..........................................24

Table 2b: Groundwater Geochemical Data - Event #2, January 2014 ..........................................25

Table 2c: Groundwater Geochemical Data - Event #3, April 2014 ...............................................26

Table 2d: Groundwater Geochemical Data - Event #4, August & October 2014 .........................28

Table 2e: Groundwater Geochemical Data - Event #5, November 2014 ......................................29

List of Figures

Figure 1: Reductive Dechlorination of TCE ....................................................................................2

Figure 2: Site Map ...........................................................................................................................6

Figure 3: April & November 2014 Shallow Groundwater Data Map - TCE .................................11

Figure 4: April & November 2014 Deep Groundwater Data Map - TCE .....................................12

Figure 5: April 2014 Shallow Groundwater Dissolved Oxygen Data Map ...................................14

Figure 6: April 2014 Deep Groundwater Dissolved Oxygen Data Map ......................................15

viii

List of Acronyms

AOC Area of Concern

ATSDR Agency for Toxic Substances and Disease Registry

bls Below Land Surface

°C Degrees in Celsius

CDC Centers for Disease Control and Prevention

COC Constituent of Concern

DCE Dichloroethylene

DNAPL Dense Non-Aqueous Phase Liquid

DO Dissolved Oxygen

EPA Environmental Protection Agency

GIS Geographical Information System

LNAPL Light Non-Aqueous Phase Liquid

MDL Method Detection Limit

mg/L Milligram per Liter

MNA Monitored Natural Attenuation

mV Millivolt

MW Monitoring Well

ORP Oxidation-Reduction Potential

PCE Tetrachloroethylene

PSP Phase Separated Product

PWR Partially Weathered Rock

TCE Trichloroethylene

VaDEQ Virginia Department of Environmental Quality

VOC Volatile Organic Compound

VC Vinyl Chloride

1

Introduction

Trichloroethylene (TCE) is a chlorinated solvent compound that is widely used in many

industrial and commercial processes throughout the world (EPA/635/R-09/011F, 2011). TCE and

many of its breakdown products may contaminate soil and groundwater when released via

accidental spills of product or intentional dumping of waste (EPA/635/R-09/011F, 2011). The

United States Centers for Disease Control and Prevention’s Agency for Toxic Substances and

Disease Registry (ATSDR) states that TCE is the most commonly reported organic contaminant

in groundwater (2001). For the purposes of this study, contamination will be defined as the

introduction of a compound (e.g. TCE) into an environmental medium (e.g. groundwater, soil) in

a concentration that makes the medium unfit for its next intended use (EPA Glossary, 2013).

ATSDR estimates between 9 and 34 percent of drinking water supply sources are contaminated

with TCE, though most are in compliance with the established national maximum contaminant

level (CDC, 2011). The United States Environmental Protection Agency (EPA) has classified

TCE as a human carcinogen as well as attributing various endocrine, reproductive, digestive,

excretory, and immunological system disorders to acute and chronic exposure of TCE (EPA

IRIS, 2013 and McParland and Bates, 2002).

Once TCE contamination above regulatory standards has been identified in the

environment, in most cases, identification of a source zone(s) and delineation of the extent of

affected area follows. Remedial activities are often necessary to reduce risk of human and

wildlife exposure, or to prevent TCE from further spreading to additional properties or

environmentally sensitive areas. A wide variety of remediation methods exist, such as

excavation, pump and treat systems, bioremediation, permeable reactive barriers, volatization

2

technologies, and even tree based phytoremediation. Applications such as these can be

technically challenging and costly, and effectiveness site specific (Kueper, 2014).

Alternatively, TCE can break down or attenuate through natural processes, eventually

resulting in stable, non-toxic or non-carcinogenic compounds (Figure 1). TCE breakdown

products include dichloroethylene (cis-1,2, trans-1,2, and 1,1-DCE), vinyl chloride (VC), and

ethene. Monitoring of this TCE biodegradation can be a suitable cost-effective course of

remedial action for a contaminated site, if sub-surface conditions as explained in later sections

are amenable (EPA/600/R-04/027, April 2004). Of 178 hazardous waste sites surveyed in a study

by McGuire et. al. (2004), monitored natural attenuation (MNA) was determined to be a suitable

addition to existing remedial efforts at over 75 percent of the sites, and at 30 percent was

determined to be effective enough to become the only remedial action at the sites.

Figure 1: Reductive Dechlorination of TCE

3

This case study will focus on the natural attenuation of historical chlorinated solvent

releases at an industrial manufacturing facility in Virginia, referred to as the site. The primary

constituent of concern for this study will be TCE. The areas of impacted groundwater, referred to

as the plume, will be examined and categorized according to occurrence of the source product

TCE, light and dense non-aqueous phase liquids, TCE breakdown or daughter products, and

geochemical properties. Historical sampling data from January 2011 through November 2014

will be analyzed in this study. The United States Environmental Protection Agency’s Technical

Protocol for Evaluating Natural Attenuation of Chlorinated Solvents in Ground Water

(EPA/600/R-98/128, 1998) will be used as guidance in this study. This document details the

EPA's approach for applying and assessing MNA as a cleanup tool for chlorinated solvents in

groundwater. MNA can work as the sole remedial option or with other more active remedial

tools at some sites where biogeochemical conditions favor natural processes that degrade or

immobilize harmful contaminants (Early, 2007).

All processes involving the industrial use of TCE on the site have been discontinued, so

no further contaminant release is expected. The goal of this study is to use recent groundwater

data to determine which parts of the groundwater plume on the site are amenable to MNA and

which are not (Petrisor and Wells, 2008). Areas that are actively breaking down contaminants

and areas where the breakdown process has stalled will be identified (Kuchovsky and Sracek,

2007) to indicate where active remedial activities may be required.

4

Methods

The site consists of approximately 149 acres between a highway to the south and a river

to the north (Figure 2). The site is bisected by an unnamed intermittent stream beginning at the

highway and ending at the river. The eastern portion of the site is undeveloped and covered with

scrub trees and underbrush. The western portion of the site contains a large manufacturing

building and parking lots on a raised plateau, which slope down to the unnamed stream, a low

point on the site. The northern edge of this plateau is bounded by an embankment that slopes

down to a flood plain of the river.

According to employee interviews and review of historical site information, the plant has

manufactured and finished metal parts since approximately 1953. In early 1980, the plant reportedly

experienced two TCE surface spills that resulted in groundwater contamination at the plant site. In

addition, due to past unregulated disposal practices, oil and TCE have contaminated the soil and

groundwater at the plant site. Between 1980 and 1987, the plant began a series of groundwater

investigations to better understand the impacts associated with the spills on groundwater. The

investigations involved installation of groundwater wells, and the installation of a groundwater

recovery system to capture oil and TCE believed to be migrating towards the river, located along the

northern site boundary.

Bedrock consists of gray/dark gray inter-bedded shale to a depth of approximately 140

feet below land surface (ft bls) (Amec 2011, 2015). The bedrock has a medium hardness but

becomes soft in moderate to highly fractured, water bearing zones. Fracture density decreases

with depth. The hydrogeology of the site is complex. The dynamic series of faulting and folding

that have occurred have caused increased fracture density in the upper portions of the bedrock.

5

Because the bedrock is relatively shallow, the majority of the groundwater is located within the

bedrock, although in some areas the water table is present in the partially weathered rock (PWR)

zone, just above the bedrock.

The property has several environmental areas of concern (AOCs) as described in

subsequent sections in this document. Therefore, the site area is best described as the area where

those current AOCs exist. As such, the site is currently described as those areas that include

AOCs 1, 2 and 3 (see Figure 2).

AOC-1 - Main Plant Area - This area includes main building operational areas around

the building exterior and beneath the building. Soil and groundwater impact from

manufacturing processes has been and still is the source of dissolved and phase separated

product (PSP) in the area. The PSP includes both chlorinated solvents (i.e., DNAPL) and

metal cutting oils (i.e., LNAPL).

AOC-2 - Oil/TCE Impact Area - Soil and groundwater impact has been and still is the

source of dissolved and PSP in the area. Residual impact in soil from waste material found

in test pits and cutting oil is still present in potentially well defined locations (i.e., burial

pits and trenches) within the embankment and floodplain portions of this area. This source

material will continue to leach dissolved LNAPL/DNAPL to groundwater. Groundwater

impact of dissolved compounds and PSP is widespread in this area and generally defined

horizontally and vertically on the property.

AOC-3 - Ditch Area - The area along the northwestern property boundary is littered with

buried and partially buried drums. Information about historical operations in this area or if

the drums once contained fluids or other materials is unknown.

6

7

Natural attenuation of contaminants of concern can be evaluated through analyses of

geochemical parameters and contaminant trends (EPA/600/R-98/128, 1998). Natural attenuation

includes physical processes, such as dispersion, diffusion, dilution and volatilization; and

chemical processes, including sorption; abiotic reactions; and biological processes (Sale, 2011).

The physical processes and sorption result in the reduction of concentration and mobility of

COCs in groundwater; however, these processes are non-destructive means for reducing

contaminant concentrations (Sale, 2011). Destructive processes, which include chemical and

biological processes, result in the reduction of the total mass of COCs in groundwater. These

destructive processes significantly contribute to the natural attenuation of COCs (McGuire,

2004).

There are multiple lines of evidence that can be evaluated to demonstrate that natural

attenuation is occurring. The primary line of evidence includes an analysis showing loss of

contaminant mass or reduction in groundwater concentrations to show that the groundwater

plume is shrinking, stable or expanding (Truex, 2007).

A total of 84 groundwater monitoring wells were installed on the site between 1980 and

2014. Limited data prior to 2010 was recovered for this site, so for the purposes of this study,

only data from 2011 until 2014 is used (Amec 2011, 2015). The overall direction of groundwater

flow at the site has been determined to be north-northeast from the plant towards the river, with a

small component of radial groundwater flow close to the plant. Groundwater samples were

collected using low-flow techniques (EPA Low Flow, 2010) using a submersible or peristaltic

pump. Geochemical parameters were measured, including conductivity, dissolved oxygen, pH,

oxidation reduction potential, turbidity, and temperature. Periodic measurements of these

parameters collected during well purging were used to verify when stabilized conditions were

8

achieved, which is necessary to insure representative samples (EPA Low Flow, 2010). Samples

were collected in sterile, laboratory provided bottles with the appropriate preservatives and

immediately placed on ice. The samples were transported under chain of custody to a certified

laboratory where they were analyzed within hold time for volatile organic compounds by gas

chromatography/ mass spectrometry (EPA method 8260B, EPA, 1996).

Contaminant trends were examined using tabulated analytical data (Table 1 in Appendix

A) from monitoring wells in which groundwater had been sampled for a minimum of three

sampling events. Concentrations of TCE and breakdown products DCE (1,1; cis-1,2; and trans-

1,2), and VC between monitoring events were determined to be generally increasing, decreasing,

stable, or no trend. Data for concentrations of ethene was not included as comprehensive

analyses for this constituent have not been performed. Statistical contaminant trend analyses

were not performed as that process, specifically using the Mann-Kendall Toolkit by GSI,

requires at least four independent sampling events per well. Data were only available for three

complete sampling events.

Secondary lines of evidence that can be used to characterize MNA include an evaluation

of geochemical parameters (EPA/600/R-98/128, 1998 and Truex, 2007). Geochemical

parameters, including dissolved oxygen (DO), oxidation-reduction potential (ORP), and

temperature, were used to evaluate whether or not intrinsic biodegradation was occurring in the

aquifer. An evaluation of these geochemical parameters for characterizing MNA have been

provided below based on the information collected during the groundwater monitoring events.

The geochemical parameter measurements evaluated have been provided in Tables 2a, 2b, 2c,

2d, and 2e in Appendix A. Dissolved oxygen is the most thermodynamically preferred electron

acceptor used by microbes for biodegradation of organic carbon (EPA/600/R-98/128, 1998).

9

Anaerobic bacteria generally cannot function when DO concentrations are greater than

approximately 0.5 mg/L, so at these concentrations reductive dechlorination of VOCs does not

typically occur (EPA/600/R-98/128, 1998). The presence of a carbon source in the aquifer can be

used by aerobic microorganisms during respiration; as the aerobic microbes use the carbon

source, DO concentrations decrease.

Dissolved oxygen (DO) concentrations from the most recent comprehensive groundwater

monitoring event conducted in April 2014 at each well were classified as generally indicative of

aerobic (DO greater than 0.5 milligrams per Liter (mg/L)) or anaerobic (DO less than 0.5 mg/L)

subsurface conditions.

Oxidation-reduction potential (ORP) measures the electron activity and the relative

tendency for the solution to transfer or accept electrons. Negative ORP values indicate that

anaerobic conditions exist in the groundwater.

10

Results and Discussion

The groundwater data collected at the site indicated several COCs were found to exceed

the applicable regulatory standards, requiring corrective measures to restore the groundwater

quality to concentrations protective of human health and the environment (Figures 3 and 4). To

evaluate the potential degradation of the site COCs, a limited geochemical and contaminant trend

analysis was conducted. A comprehensive and detailed contaminant trend analysis was not

conducted due to the limited data available on newly installed monitoring wells across the site.

These data, as described below, were used to evaluate the effectiveness of MNA as a potential

remedial approach.

A review of volatile organic compound (VOC) data in AOCs 1, 2 and 3 indicated that

degradation of TCE was occurring based on the presence of degradation products in the

groundwater (Table 1); however, degradation appears to be stalled at cis-DCE in the vicinity of

the main plant area in both the shallow and deep aquifers. In open areas surrounding the

building and in the floodplain area (i.e., AOC 2), VC was detected in both the shallow and deep

aquifers. VC indicates that the degradation of TCE is nearing the final stages.

11

12

13

The DO measurements collected during the most recent comprehensive groundwater

monitoring event conducted in April 2014 ranged from 0.05 mg/L in the sample from MW-124S

to 9.94 mg/L in the sample from ASR-33S. In the shallow monitoring wells surrounding the

downgradient sides of plant building DO concentrations were typically less than 0.5 mg/L,

indicating that anaerobic conditions were most likely present in the groundwater beneath the

building (Figure 5). Groundwater flow has been determined to flow radially away from the

main plan area. DO concentrations tended to be higher (i.e., >0.5 mg/L) in areas that were not

covered by the building and in the floodplain area (i.e., AOC 2). The DO concentrations in the

deep aquifer were more irregular and did not exhibit much of a spatial trend; however, DO

concentrations were typically greater than 0.5 mg/L in groundwater from the deep monitoring

wells sampled (Figure 6). Based on the varying DO concentrations, it appears that there are

areas of aerobic conditions and anaerobic conditions on the site.

ORP measurements in the monitoring wells measured range from -203 mV to 235 mV.

The ORP measurements were generally positive, indicating that more aerobic conditions exist in

the aquifer. Additionally, ORP reactions occur in groundwater with pH values ranging from 6 to

8 standard units; the pH ranged from 5.41 to 10.6 standard units. pH values of less than 6.5 and

greater than 9 are not optimal for reductive dechlorination of chlorinated VOCs.

The groundwater temperature has a direct relationship with microbial activity, which

readily occurs between the temperatures of 13 to 26 degrees Celsius (°C). During this sampling

event, temperature ranged from 9.77 °C to 23.51 °C. These temperatures are within the range,

with some outliers, for microbial activity to occur in the groundwater beneath the site.

14

15

16

Conclusions

In summary, this study used recent groundwater data to determine which areas of the

groundwater contamination plume on site are amenable to natural attenuation and which are not.

The primary constituent of concern for this study was TCE. The plume was examined and

categorized according to occurrence of the source product TCE, light and dense non-aqueous

phase liquids, TCE breakdown or daughter products, and geochemical properties. Historical

sampling data from January 2011 through November 2014 was analyzed in this study. The

concentrations of TCE present indicate that DNAPL material is present in the groundwater in all

AOCs. More aggressive remedial methods are needed to reduce concentrations in these DNAPL

areas.

The geochemical parameters indicate that there are pockets of aerobic and anaerobic

conditions beneath the site. Anaerobic conditions are more prevalent beneath the building in

AOC 1, while most other areas of the site are more aerobic. The conditions do not appear to be

favorable for anaerobic biodegradation of VOCs in the areas downgradient of the building as

evidenced by DO and ORP values. Further analysis shows however that aerobic cometabolism

may be occurring in portions on the site, specifically in the flood plain between the plant and the

river, as evidenced by ORP values. Bacterial analyses is necessary to confirm if aerobic

cometabolism is an active attenuation process on site. The presence of daughter products of the

primary VOCs in the groundwater across the site indicate that degradation is occurring.

A detailed evaluation of contaminant data from key wells could not be conducted for the

site due to the large number of new monitoring wells installed across the site during recent site

characterization assessment activities. As described above, statistical contaminant trend analyses

were not performed as that process, specifically using the Mann-Kendall Toolkit by GSI,

17

requires at least four independent sampling events per well. Detailed and comprehensive

contaminant trend analyses should be performed when there are a minimum of four data sets for

each monitoring well. Laboratory and trend analyses for concentrations of ethene should be

included in future sampling events as this compound succeeds VC in the attenuation process.

This can enable greater understanding of the final stages of attenuation on site.

This case reports the feasibility of application of MNA at a specific site. Imminent human

or sensitive ecological habitat exposure risk can limit the flexibility of using more cost effective

remedial options such as MNA. The immediate need to drive down source concentrations using

active measures can rule out MNA due to the relatively longer amount of time needed for natural

processes to degrade contaminants. Exposure pathways for humans, such as vapor intrusion,

need to be taken into consideration and properly assessed prior to deciding remedial action plans.

The findings in this paper raise the question of whether at other sites there is a noticeable

correlation between proximity of a large structure to impacted groundwater and classifying

subsurface natural attenuation potential. Further research is needed to identify is there is a trend

in anaerobic conditions near buildings or impermeable surfaces.

The measured high concentrations of TCE and occurrence of DNAPL prohibit the

feasibility of MNA as a sole remedial option for the site. However, data collected indicates that

areas of the site are amenable to MNA, and that MNA may be able to play a larger role when

applied in combination with more aggressive clean up action at source areas. Further trend

analysis is needed as more data becomes available. This paper has demonstrated that while MNA

is an enticing and cost effective remedial alternative, exclusive reliance on natural attenuation for

contaminant degradation is not practical for all sites. Site specific characterization of degradation

potential is crucial for optimal source reduction and overall site reclamation.

18

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Contaminant Focus: Trichloroethylene. [Online] March 4, 2015. [Cited: March 13, 2015].

http://clu-in.org/contaminantfocus/default.focus/sec/Trichloroethylene_(TCE)/cat/Overview/

U.S. Environmental Protection Agency. Toxicological Review of Trichloroethylene (CASRN 79‐

01‐6). EPA/635/R-09/011F. 2011.

U.S. Environmental Protection Agency. Trichloroethylene (CASRN 79‐01‐6). Integrated Risk

Information System. [Online] August 9, 2013. [Cited: July 13, 2014].

http://www.epa.gov/iris/subst/0199.htm

U.S. Environmental Protection Agency. Method 8260B: Volatile Organic Compounds by Gas

Chromatography/ Mass Spectrometry. 1996.

22

Appendix A

23

Tric

hlo

roe

thyl

en

e

1,1

-Dic

hlo

roe

thyl

en

e

cis-

1,2

-

Dic

hlo

roe

thyl

en

e

tran

s-1

,2-

Dic

hlo

roe

thyl

en

e

Vin

yl c

hlo

rid

e

Tric

hlo

roe

thyl

en

e

1,1

-Dic

hlo

roe

thyl

en

e

cis-

1,2

-

Dic

hlo

roe

thyl

en

e

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,2-

Dic

hlo

roe

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e

Vin

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hlo

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e

5 41.4 2370 100 16.6 5 41.4 2370 100 16.6

Jan-11 142 5.3 9.3 BMDL BMDL Jan-11 4 BMDL 20.2 BMDL BMDL

Oct-13 17.8 BMDL BMDL BMDL BMDL Oct-13 1.61 BMDL 14.2 BMDL 1.93

Apr-14 23.9 1.23 0.67 J BMDL BMDL Apr-14 5.75 BMDL 57.2 0.53 J 11.9

Jan-11 763 3100 240 BMDL BMDL Jan-11 1.4 17.4 4100 7.7 5510

Oct-13 90.9 3780 63.7 BMDL 1.28 Oct-13 BMDL 1.51 J 661 0.570 1770 J

Apr-14 40.2 1700 45.3 BMDL 1.61 Apr-14 1.5 11 1450 7.14 1280

Jan-11 3080 3.1 102 1.1 9.2 Jan-11 60.2 25.5 1790 BMDL 3550

Oct-13 559 BMDL 40.7 BMDL 7.89 Oct-13 BMDL 4.04 1370 6.03 2320

Apr-14 1920 BMDL 39.7 0.5 J BMDL Apr-14 0.65 J 4.16 782 2.47 958

Jan-11 213 40.1 25600 228 BMDL Jan-11 87.4 BMDL 128 3.5 1.8

Oct-13 15.3 BMDL 41.6 BMDL 0.550 Oct-13 12.6 BMDL 8.77 BMDL BMDL

Apr-14 9.68 BMDL 36.7 BMDL BMDL Apr-14 1.65 BMDL 2.49 BMDL BMDL

Jan-11 247000 212 6120 BMDL 374 Jan-11 141000 286 7200 60.1 615

Oct-13 752000 BMDL 8600 BMDL BMDL Oct-13 124000 511 5930 93.3 25.5

Apr-14 809000 BMDL 5260 BMDL BMDL Apr-14 44500 BMDL 2390 BMDL BMDL

Jan-11 76.6 1.5 1 BMDL BMDL Jan-11 6210 101 13500 100 1870

Oct-13 95.2 1.22 9.18 BMDL BMDL Oct-13 4650 58.5 13100 54.3 970

Apr-14 10.9 BMDL 0.63 J BMDL BMDL Apr-14 2520 106 21800 192 1020

Jan-11 7000 BMDL 439 BMDL BMDL Jan-11 3.3 BMDL 4.3 BMDL BMDL

Oct-13 5120 J BMDL 180 BMDL BMDL Oct-13 2.04 BMDL BMDL BMDL BMDL

Apr-14 3570 18.6 34.2 BMDL BMDL Apr-14 1.37 BMDL BMDL BMDL BMDL

Jan-11 246 1.0 J 15.5 BMDL 7.2 Jan-11 401000 162 1470 BMDL BMDL

Oct-13 593 BMDL 25.2 1.39 6.13 Oct-13 376000 BMDL 1000 BMDL BMDL

Apr-14 671 1.64 74.8 BMDL 4.61 Apr-14 222000 BMDL 860 J BMDL BMDL

Jan-11 146 BMDL 0.3 J BMDL BMDL Jan-11 19400 20.3 1380 9.9 6.5

Oct-13 110 BMDL BMDL BMDL BMDL Oct-13 1520 1.92 206 1.65 BMDL

Apr-14 24.8 BMDL BMDL BMDL BMDL Apr-14 620 BMDL 22.4 BMDL BMDL

Jan-11 16 4.7 4.7 BMDL 0.6 J Jan-11 3.3 0.5 J 202 2.6 125

Oct-13 3.06 BMDL 5.09 BMDL BMDL Oct-13 4.19 BMDL 106 3.00 78.2

Apr-14 1.75 BMDL 1.12 BMDL BMDL Apr-14 2 BMDL 69.9 2.1 76.1

Jan-11 29.4 BMDL 1.8 BMDL BMDL Jan-11 396 4 539 3.1 55.3

Oct-13 0.590 BMDL 3.02 BMDL BMDL Oct-13 66.0 5.29 500 4.20 33.9

Apr-14 3.17 BMDL 11.1 BMDL BMDL Apr-14 29.9 2.8 526 2.65 14.8

Jan-11 31600 804 2000 24.8 82.3 Jan-11 22 13 7210 37.6 940

Oct-13 13900 242 2880 37.5 147 Oct-13 1.68 4.68 1190 1.90 92.0

Apr-14 15600 242 3770 59 J 301 Apr-14 1060 1.93 219 2.75 BMDL

Jan-11 3200 48.2 16900 139 589 Jan-11 4.5 1.3 653 1.1 679

Oct-13 1950 23.1 11400 82.0 249 Oct-13 5.86 2.91 743 8.02 366

Apr-14 2680 17.5 5300 110 18.1 Apr-14 2.28 3.96 1380 16.4 375

Notes: Notes:

Highlighted values exceed their respective Tier III Screening Concentration Highlighted values exceed their respective Tier III Screening Concentration

BMDL = Below laboratory method detection limit BMDL = Below laboratory method detection limit

μg/LMo

nit

ori

ng

We

ll ID

Sam

plin

g D

ate

Mo

nit

ori

ng

We

ll ID

Sam

plin

g D

ate

μg/L

VRP Tier III Groundwater

Screening Concentrations

VRP Tier III Groundwater

Screening Concentrations

ASR-1s MW-103

ASR-2s MW-105

ASR-3s ASR-107s

ASR-3d MW-110

ASR-4s MW-113s

ASR-5s ASR-117d

ASR-7s MW-120s

ASR-9s ASR-120d

VRP Tier III Groundwater Screening Concentrations = Virginia Voluntary Remediation

Program site-specific analysis weighs current and potential exposure scenarios for the

population(s) of concern and characteristics of the affected groundwater. [Source:

Virginia Voluntary Remediation Regulations,9 VAC 20-160-90(C)(2)(c)]

VRP Tier III Groundwater Screening Concentrations = Virginia Voluntary Remediation

Program site-specific analysis weighs current and potential exposure scenarios for the

population(s) of concern and characteristics of the affected groundwater. [Source:

Virginia Voluntary Remediation Regulations,9 VAC 20-160-90(C)(2)(c)]

Table 1 (1): Analytical Data for Groundwater Table 1 (2): Analytical Data for Groundwater

ASR-19s MW-134

MW-101s MW-137

J = Detected but below the laboratory reporting l imit; therefore, result is an estimated

concentration.

J = Detected but below the laboratory reporting l imit; therefore, result is an estimated

concentration.

ASR-10s MW-121

ASR-16s MW-124

ASR-17s ASR-133d

24

Monitoring

Well IDDate Aquifer Zone Temperature (oC) pH

Conductivity

(mS/cm)

Turbidity

(mg/L)

DO

(mg/L)

Oxidation /

Reduction

Potential (mV)

Fe+2

(mg/L)

ASR101D 10/3/2013 Lower BR 17.83 7.64 3.96 75.0 0 77 0

ASR107S 10/3/2013 Upper BR 18.53 6.68 0.584 0.00 0 -71 2

ASR10S 10/4/2013 Upper BR 17.31 6.79 0.787 0.80 3.68 133 0

ASR117D 10/3/2013 Lower BR 16.03 7.23 1.06 0.00 0 37 0.6

ASR120D 10/2/2013 Lower BR 19.95 7.55 0.75 4.00 4.74 82 0

ASR133D 10/3/2013 Upper BR 20.23 7.4 0.465 0.00 0 -82 0

ASR15S 10/2/2013 Upper BR 19.05 7.42 0.531 0.00 0.78 78 0

ASR16S 10/2/2013 Sap. 17.78 7.41 0.537 0.80 0 -30 0

ASR17S 10/2/2013 Sap. 17.87 7.37 0.405 0.00 0 34 0.5

ASR18S 10/2/2013 Upper BR 13.38 7.85 0.225 0.00 0.34 68 0

ASR19S 10/4/2013 Sap./BR 20.39 5.2 0.327 0.00 0 184 0

ASR1S 10/2/2013 Sap./BR 20.83 6.37 0.187 0.00 0.86 103 0

ASR2S 10/2/2013 Sap./BR 20.56 6.77 0.686 0.00 0 144 0

ASR3D 10/4/2013 Lower BR 21.79 7.89 0.344 52.2 0 -38 0

ASR3S 10/4/2013 Sap./BR 21.83 7.08 0.438 0.00 0 82 0

ASR4S 10/4/2013 Sap./BR 19.99 7.46 0.457 0.00 0 72 0

ASR5S 10/4/2013 Sap./BR 19.04 6.59 0.345 0.00 1.39 145 0

ASR7S 10/4/2013 Sap./BR 15.77 6.01 0.434 0.00 0 137 0

ASR9S 10/4/2013 Upper BR 18.38 7.31 0.432 38.5 3.19 32 0

MW101S 10/3/2013 Sap./BR 14.4 7.14 0.381 183 0 0 0

MW103S 10/3/2013 Sap./BR 16.34 6.87 0.351 0.00 0 -47 1.4

MW105 10/3/2013 Sap./BR 19.92 6.88 0.566 0.00 0 -48 4.6

MW110 10/3/2013 Sap./BR 15.39 6.46 0.321 0.00 1.62 184 0

MW113S 10/3/2013 Sap./BR 14.89 7.09 0.741 0.00 0 -48 0

MW114 10/3/2013 UN 18.85 6.46 0.4 0.00 0.32 122 0

MW120S 10/2/2013 Upper BR 18.7 7.38 0.437 42 0 126 0

MW121 10/2/2013 Upper BR 28.3 7.5 0.616 6.6 0 125 0

MW124 10/3/2013 Sap./BR 21.6 6.74 0.477 0.00 0 -113 0

MW134 10/3/2013 Sap./BR 20.69 8.03 0.301 0.00 0 -174 1.4

MW137 10/3/2013 Sap./BR 15.42 7.26 0.608 0.00 0 -187 0

Notes:

Sap = Saprolite UN = Unknown DO = dissolved oxygen Fe+2 = Ferrous Iron

Field measurements for Fe+2 conducted using a Hach Kit Model 1R-18C, turbidity using a HACH 2100P Turbidimeter, and all other parameters measured with a YSI

556/Professional Plus Multi-Probe System.

Table 2a: Groundwater Geochemical Data - Event #1, October 2013

25

Monitoring

Well IDDate Aquifer Zone

Temperature

(oC)pH

Conductivity

(mS/cm)

Turbidity

(mg/L)

DO

(mg/L)

Oxidation /

Reduction

Potential (mV)

Fe+2

(mg/L)

ASR107DD 1/9/2014 Lower BR 13.80 7.53 1.220 8.55 0.56 -145.3 0.2

ASR15D 1/7/2014 Lower BR 9.80 7.48 0.546 2.10 1.04 -31 0

ASR19D 1/10/2014 Lower BR 9.60 7.67 0.730 8.73 3.03 119.2 0

ASR20D 1/7/2014 Lower BR 5.00 7.33 0.579 27.5 0.43 -115.9 0.2

ASR20S 1/7/2014 Upper BR 9.05 7.21 0.478 8.70 0.43 -42.1 0

ASR21D 1/6/2014 Lower BR 6.56 7.64 0.381 2.15 5.03 216 0

ASR21S 1/6/2014 Sap./BR 8.50 7.09 0.686 4.00 0.37 82.7 0

ASR22D 1/6/2014 Lower BR 6.30 7.15 0.517 10 0.39 180 0

ASR22S 1/6/2014 Upper BR 8.26 6.69 0.433 2.85 1.01 214.8 0

ASR23D 1/8/2014 Lower BR 10.67 7.1 0.612 8.56 0.42 -53.1 1

ASR23S 1/8/2014 Upper BR 12.07 5.71 0.080 9.6 3.04 199.2 0

ASR24D 1/9/2014 Lower BR 9.40 7.41 1.170 3.06 0.34 6.9 0

ASR24S 1/9/2014 Sap./BR 9.74 7.16 0.561 3.14 0.40 -62.9 1

ASR25S 1/8/2014 Sap./BR 11.00 7.08 1.020 5.52 0.38 0.6 0

ASR26D 1/7/2014 Lower BR 11.50 7.33 0.603 2.43 2.22 103 0

ASR26S 1/7/2014 Upper BR 11.21 7.16 0.483 7.6 0.31 -22.2 0

ASR27D 1/8/2014 Lower BR 11.20 90.2 0.417 6.3 1.06 -53.2 0

ASR27S 1/8/2014 Upper BR 13.40 7.07 0.840 9.2 1.38 211.9 0

ASR28S 1/8/2014 Upper BR 10.98 60.99 0.472 1.19 1.23 178 0

ASR29S 1/7/2014 Upper BR 9.73 7.31 0.501 1.05 0.90 92 0

ASR30S 1/9/2014 Upper BR 12.69 6.58 0.400 8.9 0.80 58.6 0

ASR31S 1/9/2014 Upper BR 10.98 6.93 0.525 9.2 0.89 40.1 0

ASR32S 1/9/2014 Upper BR 11.32 6.94 0.469 2.18 0.36 50.6 0

ASR33D 1/8/2014 Lower BR 11.30 7.29 1.050 2.00 0.35 -46.9 0.3

ASR33S 1/8/2014 Sap./BR 10.50 7.29 0.940 1.01 4.66 280.2 0

ASR34S 1/10/2014 Upper BR 14.28 7.19 0.482 3.98 4.84 -10.4 0

ASR35D 1/7/2014 Lower BR 8.70 7.4 0.548 1.50 0.32 31 0

ASR35S 1/7/2014 Upper BR 11.04 7.1 0.550 2.01 0.26 32.5 0

ASR4DD 1/9/2010 Lower BR 14.50 8.34 1.140 6.81 3.63 -10.9 0

MW108D 1/9/2014 Lower BR 11.70 7.23 1.310 2.68 1.82 84.9 0

MW113D 1/9/2014 Lower BR 12.65 7.31 0.649 7.86 3.21 54.6 0

MW124DD 1/8/2014 Lower BR 12.61 8.8 0.334 9.08 0.21 -36.9 0

Notes:

Sap = Saprolite UN = Unknown DO = dissolved oxygen Fe+2 = Ferrous Iron

Field measurements for Fe+2 conducted using a Hach Kit Model 1R-18C, turbidity using a HACH 2100P Turbidimeter, and all other parameters measured

with a YSI 556/Professional Plus Multi-Probe System.

Table 2b: Groundwater Geochemical Data - Event #2, January 2014

26

Monitoring Well

IDDate Aquifer Zone

Temperature

(oC)pH

Conductivity

(mS/cm)

Turbidity

(mg/L)

DO

(mg/L)

Oxidation /

Reduction

Potential (mV)

Fe+2

(mg/L)

ASR101D 4/21/2014 Lower BR 15.91 7.26 3.537 nm 1.77 165.1 0.0

ASR107DD 4/22/2014 Lower BR 13.33 7.47 0.528 4.01 0.14 -103.5 1.0

ASR107S 4/22/2014 Upper BR 13.93 6.57 0.61 9.8 0.47 -144.8 0.0

ASR10S 4/15/2014 Upper BR 1.77 6.99 0.782 3.16 1.08 50.7 0.0

ASR117D 4/22/2014 Lower BR 13.88 6.77 1.271 2.01 0.64 -125.3 0.7

ASR120D 4/24/2014 Lower BR 14.68 7.29 0.783 nm 0.91 -48.8 1.2

ASR133D 4/22/2014 Upper BR 12.79 7.24 0.564 3.14 0.99 64.5 0.0

ASR15D 4/15/2014 Lower BR 13.23 7.54 0.471 9.6 0.32 -66.5 0.0

ASR15S 4/15/2014 Upper BR 13.01 7.29 0.549 2.75 2.11 29.3 0.5

ASR16S 4/16/2014 Sap 10.25 7.28 0.398 4 2.59 91.9 0.0

ASR17S 4/16/2014 Sap 9.97 7.15 0.496 4.22 0.42 114.5 0.0

ASR19D 4/21/2014 Lower BR 16.15 7.54 0.42 4.16 0.37 -29.4 0.0

ASR19S 4/24/2014 Sap./BR 13.51 5.67 0.45 1.01 0.08 170.3 0.6

ASR1S 4/15/2014 Sap./BR 13.28 6.39 0.233 8.60 3.62 96.7 0.0

ASR20D 4/16/2014 Lower BR 9.77 7.37 0.375 1.66 0.72 0.7 0.2

ASR20S 4/16/2014 Upper BR 10.07 7.08 0.394 4.12 0.71 38.2 0.1

ASR21D 4/14/2014 Lower BR 14.29 7.34 0.39 1.98 2.38 80.9 0.0

ASR21S 4/14/2014 Upper BR 13.83 7.11 0.615 10.00 0.15 97.1 0.0

ASR22D 4/15/2014 Lower BR 14.71 7.21 0.476 9.8 0.14 162.1 0.0

ASR22S 4/15/2014 Upper BR 13.1 6.84 0.436 2.34 0.92 105.1 0.5

ASR23D 4/17/2014 Lower BR 13.17 6.96 0.652 2.01 0.29 -123.1 0.3

ASR23S 4/17/2014 Upper BR 11.78 5.41 0.064 7.75 2.68 238.2 0.2

ASR24D 4/17/2014 Lower BR 10.41 7.47 0.429 0.57 0.81 -65.5 0.0

ASR24S 4/17/2014 Sap./BR 8.54 7.11 0.567 2.64 0.37 -63.9 1.1

ASR25S 4/22/2014 Sap./BR 10.11 6.84 0.551 2.60 1.07 5.7 0.0

ASR26D 4/16/2014 Lower BR 13 7.4 0.527 1.62 0.71 -88.8 0.0

ASR26S 4/16/2014 Upper BR 11.31 7.21 0.438 10.0 0.11 57.0 0.0

ASR27D 4/17/2014 Lower BR 13.78 8.05 0.25 8.46 0.79 -141.9 0.2

ASR27S 4/17/2014 Upper BR 14.01 6.5 0.056 7.53 5.41 -108.8 0.1

ASR28S 4/16/2014 Upper BR 14.12 6.97 0.44 1.28 0.45 26.2 0.2

Notes:

Sap = Saprolite UN = Unknown DO = dissolved oxygen Fe+2 = Ferrous Iron

Field measurements for Fe+2 conducted using a Hach Kit Model 1R-18C, turbidity using a HACH 2100P Turbidimeter, and all other parameters

measured with a YSI 556/Professional Plus Multi-Probe System.

Table 2c (1): Groundwater Geochemical Data - Event #3, April 2014

27

Monitoring Well

IDDate Aquifer Zone

Temperature

(oC)pH

Conductivity

(mS/cm)

Turbidity

(mg/L)

DO

(mg/L)

Oxidation /

Reduction

Potential (mV)

Fe+2

(mg/L)

ASR29S 4/15/2014 Upper BR 11.46 7.27 0.454 2.02 0.82 161.0 0.0

ASR2S 4/15/2014 Sap./BR 15.81 6.95 0.914 0.16 1.12 200.3 0.0

ASR30S 4/24/2014 Upper BR 14 6.4 0.405 nm 0.12 70.7 0.0

ASR31S 4/18/2014 Upper BR 10.39 6.89 0.509 4.32 0.26 112.4 0.0

ASR32S 4/23/2014 Upper BR 10.92 6.61 0.387 8.62 0.6 44.3 0.0

ASR33D 4/22/2014 Lower BR 11.57 7.12 0.473 0.76 1.23 7.8 0.3

ASR33S 4/22/2014 Sap./BR 10.65 7.2 0.393 1.26 9.94 57.0 0.0

ASR34S 4/23/2014 Upper BR 17.78 7.12 0.54 1.65 0.12 -24.0 0.6

ASR35D 4/15/2014 Lower BR 13.07 7.19 0.395 0.88 0.85 -5.0 0.0

ASR35S 4/15/2014 Upper BR 13.28 7.13 0.58 9.2 0.13 129.4 0.0

ASR3D 4/22/2014 Lower BR 16.74 7.74 0.498 9.00 0.08 -54.6 0.0

ASR3S 4/21/2014 Sap./BR 16.25 6.85 0.264 5.98 3.47 126.2 0.0

ASR4DD 4/23/2014 Lower BR 16.76 10.6 0.546 5.16 0.55 -117.5 0.0

ASR4S 4/24/2014 Sap./BR 15.92 6.97 0.421 nm 6.55 111.3 0.0

ASR5S 4/17/2014 Sap./BR 11.17 6.69 0.411 1.34 2.62 235.6 0.2

ASR7S 4/16/2014 Sap./BR 12.12 6.62 0.383 1.72 0.5 49.5 0.1

ASR9S 4/16/2014 Upper BR 13.16 7.22 0.469 19.9 0.65 11.6 0.3

MW101S 4/21/2014 Sap./BR 17.23 7.01 0.512 36.7 0.23 112.0 0.0

MW103S 4/21/2014 Sap./BR 14.57 7.02 0.25 112 1.56 32.4 0.0

MW105 4/22/2014 Sap./BR 14.79 6.69 0.661 1.63 0.16 -92.4 2.4

MW108D 4/23/2014 Lower BR 13.03 7.02 0.567 1.00 0.53 32.8 0.0

MW110 4/16/2014 Sap./BR 10.02 6.56 0.236 36.5 5.39 172.8 0.0

MW113D 4/23/2014 Lower BR 11.94 7.07 0.673 5.13 0.76 -10.9 0.3

MW113S 4/24/2014 Sap./BR 14.65 6.9 0.628 42.0 0.19 78.9 0.0

MW120S 4/18/2014 Upper BR 14.55 7.24 0.416 9.7 0.48 114.2 0.0

MW121 4/22/2014 Upper BR 23.51 7.44 0.453 6.44 1.08 113.2 0.0

MW124DD 4/17/2014 Lower BR 12.69 8.71 0.35 37.4 0.05 -142.4 0.0

MW124S 4/17/2014 Sap./BR 11.62 7.11 0.47 5.02 0.41 -203.9 0.2

MW134 4/18/2014 Sap./BR 11.6 7.29 0.472 2.01 1.56 43.1 0.0

MW137 4/18/2014 Sap./BR 11.33 6.91 0.459 1.20 0.43 -126.8 0.0

Notes:

Sap = Saprolite UN = Unknown DO = dissolved oxygen Fe+2 = Ferrous Iron

Field measurements for Fe+2 conducted using a Hach Kit Model 1R-18C, turbidity using a HACH 2100P Turbidimeter, and all other

parameters measured with a YSI 556/Professional Plus Multi-Probe System.

Table 2c (2): Groundwater Geochemical Data - Event #3, April 2014

28

ASR108DD2 8/12/2014 Lower BR 20.64 11.68 1.628 200 3.1 60.1 nm

ASR113DD2 8/12/2014 Lower BR 21.88 7.67 0.668 9.1 0.93 17.7 nm

ASR30D 8/14/2014 Lower BR 16.88 8.87 0.344 9.2 2.67 6.8 nm

ASR34D 8/14/2014 Lower BR 18.67 7.10 0.748 190 0.63 -0.5 nm

ASR36D 8/12/2014 Lower BR 15.16 8.40 0.517 120 2.16 36.8 nm

ASR36S 8/12/2014 Upper BR 15.53 7.23 0.514 7.9 3.99 17.7 nm

ASR37D 8/14/2014 Lower BR 15.08 7.60 0.471 23 7.91 42.1 nm

ASR37DD2 8/14/2014 Lower BR 14.55 8.60 0.731 700 3.75 75.9 nm

ASR4DD2 8/14/2014 Lower BR 18.47 9.37 0.394 8.3 0.72 -64.1 nm

ASR34DD2 10/16/2014 Lower BR 18.65 12.22 1.424 7.03 0.35 -29.7 nm

ASR38D 10/16/2014 Lower BR 15.02 12.42 1.492 22.8 1.51 35.1 nm

ASR38S 10/16/2014 Sap./BR 14.62 7.26 0.459 32.2 4.29 82.2 nm

ASR39D 10/16/2014 Lower BR 13.75 7.68 0.288 29.2 0.25 60.9 nm

Notes:

Sap = Saprolite UN = Unknown DO = dissolved oxygen Fe+2 = Ferrous Iron

Field measurements for Fe+2 conducted using a Hach Kit Model 1R-18C, turbidity using a HACH 2100P Turbidimeter, and all other parameters

measured with a YSI 556/Professional Plus Multi-Probe System.

Table 2d: Groundwater Geochemical Data - Event #4, August & October 2014

Conductivity

(mS/cm)

Turbidity

(mg/L)

DO

(mg/L)

Oxidation /

Reduction

Potential (mV)

Fe+2

(mg/L)

Monitoring

Well IDDate Aquifer Zone

Temperatur

e (oC)pH

29

Monitoring

Well IDAquifer Zone

Temperature

(oC)pH

Conductivity

(mS/cm)

Turbidity

(mg/L)

DO

(mg/L)

Oxidation /

Reduction

Potential (mV)

Fe+2

(mg/L)

ASR108DD2 Lower BR 13.73 11.22 1.035 178 3.82 -164.8 0.3

ASR113DD2 Lower BR 13.73 7.53 0.507 7.05 0.86 -224.7 0.2

ASR30D Lower BR 14.6 8.67 0.396 8.76 0.52 -65.3 0

ASR34D Lower BR 17.67 8.07 0.79 9.81 2.63 -176.7 0.5

ASR34DD2 Lower BR 17.68 12.44 2.905 6.33 0.53 -50.3 1

ASR36D Lower BR 15.61 8.00 0.444 9.8 0.7 -193.7 0

ASR36S Upper BR 16.09 7.19 0.507 0.88 0.6 -59.8 0.4

ASR37D Lower BR 11.62 7.46 0.417 4.33 1.43 116.5 0

ASR37DD2 Lower BR 14.47 8.18 0.631 157 1.59 -11.3 0.3

ASR38D Lower BR 13.95 11.05 0.312 2.07 0.79 -45.2 0

ASR38S Sap./BR 13.76 7.10 0.551 4.73 1.67 -80.8 0

ASR39D Lower BR 13.36 7.85 0.309 134 0.95 -148.1 0.1

ASR39S Sap./BR nm nm nm nm nm nm 0

ASR4DD2 Lower BR 17.28 9.35 0.353 93.1 0.35 -182.8 0

Notes:

Sap = Saprolite UN = Unknown DO = dissolved oxygen Fe+2 = Ferrous Iron

Table 2e: Groundwater Geochemical Data - Event #5, November 2014

Field measurements for Fe+2 conducted using a Hach Kit Model 1R-18C, turbidity using a HACH 2100P Turbidimeter, and all

other parameters measured with a YSI 556/Professional Plus Multi-Probe System.