The geologic modeling capabilities in GMS 10 allows for automated and manual in-

terpolation of borehole data into stratigraphic layers using fence diagrams. These di-

agrams are used to construct MODFLOW layers for flow and transport simulation.

23rd Annual David S. Snipes/Clemson

Hydrogeology Symposium

March 26, 2015

Time BellSouth Auditorium Meeting Rooms 1/2 Meeting Rooms 3/4

7:30 Registration

Modeling

Moderator: Ron Falta Sampling/Characterization Moderator: Andy Alexander

Geophysics Moderator: Stephen Moysey

8:50

Development of a Practical Approach for Modeling Ma-trix Diffusion Effects in Groundwater Transport Mod-els Falta, Ronald

Comparison of the Variance from Concentration Trend of 1,2-Dichloropropane in Groundwater from Bailed Well compared to Diffusion Sam-pling Technology Alexander, Andrew

The Applications and Limita-tions of Common Geophysical Methods in Determining Bed-rock Depth Bergstrom, Jorgen

9:15

Inclusion of Faults in 3-D Numerical Simulation of Car-bon Dioxide Injection into the South Georgia Rift Basin, South Carolina Brantley, Duke

Field-Trial Results for an Ex-perimental Dual-Membrane Diffusion Sampler for Metals and Ions in Groundwater Varhol, Brad

Characterizing Bedrock and Re-sidual Soil Conditions with MASW and ERI Daniel, Joel

9:40

Geochemical Modeling for Remedial Alternatives Analy-sis of Acid Mine Drainage at the Henry Knob Former Mine Site Bruce, Christopher

Why Map Contaminant Con-centration Only? – The Im-portance of Flux Measurement using Real Time Measurement Systems Carlson, Brad

Automated High-resolution GPR Data Collection for Monitoring Dynamic Hydrologic Processes in Two and Three dimensions Mangel, Adam

10:05

Hydrologic Effects and Risks Associated with Increased Upward Flux of Saline Water Murdoch, Lawrence

Comparison Study of Multiple Groundwater Sampling Tech-niques in Fractured Bedrock Handley, David

2-Dimensional Geophysical Im-aging of Infiltration in a Homog-enous Medium Lytle, Blake

10:30 Break/Please move to the Main Ballroom

11:00 Keynote: Numerical Models for Evaluating the Competitive Use of the Subsurface: The Influence of Energy Storage and Production in Groundwater, Rainer Helmig

12:00 Lunch

Speaker Schedule March 26, 2015

Time BellSouth Auditorium Meeting Rooms 1/2 Meeting Rooms 3/4

Remediation

Moderator: Patrick Hicks Groundwater

Moderator: Bruce Campbell

NA Degradadation / Grad Research

Moderator: Jim Castle

1:05

Chemical Fixation of Priority Heavy Metals in Soil, Sediment and Groundwater using Meta-Fix™ Reagents Hicks, Patrick

Development of a Groundwa-ter-Flow Model of the Atlantic Coastal Plain, Aiken County, South Carolina Campbell, Bruce

Photocatalysis of Commercial Naphthenic Acids using Fixed-film TiO2 McQueen, Andrew

1:30

Reductive Dechlorination in Sites with High Sulfate and Low (apparent) DHC (dehalococcoides) Bacteria and Other Paradoxes Rossabi, Joseph

Assessment of Groundwater Quality of Atlantic Coastal Plain Aquifers, Aiken County, South Carolina Landmeyer, James

Water Properties Affecting Pho-to-catalytic Oxidation of Com-mercial Naphthenic Acids Using Titanium Dioxide Kiekhaefer, Rebecca

1:55

Case Study: Gravity Fed ISCO Injection for DNAPL Treatment in a Perched Water Zone Byrd, Jennifer

Developing the U.S. Geologi-cal Survey StreamStats Web Application for South Carolina Feaster, Toby

White-rot Fungal Degradation of Naphthenic Acids Muller, Samuel

2:20

Cost-Effective Site Characteri-zation and Site Remediation Strategies: A Community-Supported Model of What Works Even With a Limited Budget Redmond, Jymalyn

Forensic Investigation of a Flooded Limestone Aggregate Quarry to Assess Karst Fea-tures Hydraulically Connecting the Pit and a Nearby Stream Thompson, Nils

Remapping of the Northern Por-tion of the Six Mile Quadrangle Sellers, Victoria

2:45

Comparison of Air Sparge/ Soil Vapor Extraction Pilot Tests from Four Chlorinated Ethene Impacted Sites in Distinct Geo-logic Settings of the Piedmont Hollifield, Edward

How to Get the Most Out of Aggressive Fluid Vapor Re-covery (AFVR) Shinall, Brian

Estimation of PCB Contamina-tion in the Twelve Mile Creek Arm of Lake Hartwell, SC, Us-ing GIS and Statistical Tech-niques Bharadwaj, Arjun

3:10 Break

Time BellSouth Auditorium Meeting Rooms 1/2 Meeting Rooms 3/4

Geodeformation(ish) Moderator: Bill Slack

Undergrad Research Moderator: Alan Coulson

Undergrad Research Moderator: Scott Brame

3:40

In Situ Remediation Of Chlo-rinated Solvents Using Jet Fracturing Technology – Full Scale Demonstration Slack, William

The Influence of Slope on the Weathering Rates of Bi-otite Gneiss Bedrock Berisford, Jordan

Sediment Core Characteriza-tion in the Twelvemile Creek Arm of Lake Hartwell, SC Herrmann, Anthony

4:00

Tensor Strainmeter and Vec-tor Tiltmeter Design for Measuring Ground Defor-mations Associated with Flu-id Injection and/or Withdraw-al DeWolf, Scott

XRD Analysis of Soil be-tween Outcrops of Amphib-olite and Mica Schist McFarland, William

Characterization and Imaging of Pipe Flow Within a Natural Embankment Bagbey, Daniel

4:20

Using Geomechanical Meas-urements for Subsurface Characterization Hanna, Alexander

Refinement of the Seneca Fault in the Southwest Cor-ner of the Six Mile Quad-rangle Caldwell, Storm

Changes in Soil CO2 Flux from an Urban Environment due to Anthropogenic Com-paction Walters, Dana

4:40

Improvements to the Curve Number Method Using Varia-ble Initial Abstraction and Antecedent Moisture Santikari, Vijay

Re-examining the Geologic Interpretations Used to De-lineate the Seneca Fault Villanueva, Rafael

Comparative Study of Soil CO2 Flux using Eddy Covari-ance and Chamber Methods George, Shanay

5:15 Mixer at Clemson University Outdoor Lab

Workshops (Seminar Room 2) 8:30 AM - 10:30 AM "When this geologist speaks, people listen": A short course on presentation skills for Geologists Dr. Tom Temples 1:10 PM - 5:00 PM Environmental Data Science Skills using Python and ArcGIS Dr. Stephen Moysey, Scott Brame, and Patricia Carbajales

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Abstracts (Ordered by last name of first author)

Comparison of the Variance from Concentration Trend of 1,2-Dichloropropane in Groundwater from Bailed Well compared to Dif-fusion Sampling Technology Alexander, Andrew W., andy@ blecorp.com, Mark S. Preddy, and Tre-vor J. Benton, Bunnell-Lammons Engi-neering, Inc., Greenville, South Carolina Pesticide use impacted groundwater at an industrial facility located in the Blue Ridge physiographic province of North Carolina when the subject site and surrounding par-cels were used as farmland. Groundwater monitoring for the presence of 1,2-dichloropropane (DCP) in groundwater be-gan at the subject site in 1989.

Groundwater monitoring was con-ducted at varying frequencies including monthly, quarterly, semi-annually, and an-nually throughout the site’s history. Groundwater sampling was performed us-ing conventional bailed well sampling technology from 1989 through 1999. Groundwater monitoring has been per-formed via diffusion technology from 2000 through 2014 on an annual frequency.

In 1997, the subject site (and one other local site with VOC contaminated groundwater) was contemporaneously sam-pled via passive diffusion and bailed well technology to evaluate the use of diffusion sampling as a potential replacement for conventional bailed well sampling. The results were published in 1998 and 1999 and were referenced in the Technical Re-port for the Evaluation of Groundwater Diffusion Samplers (Parsons Engineering

Science, December 1999), and in the Us-er’s Guide for Polyethylene-Based Passive Diffusion Bag Samplers to Obtain Volatile Organic Concentrations in Wells – Part 2: Field Tests, Water-Resources Investigation Report 01-4061 (U.S. Geological Survey, 2001) The data indicated that diffusion sampling was a viable replacement tech-nology for conventional bailed well sam-pling. Additionally it was observed that there was some data scatter at the lower magnitude detections which was attributed to laboratory-induced variability. The sub-ject site’s regulatory authority granted ap-proval for long-term groundwater monitor-ing to be performed using diffusion tech-nology beginning in 2000.

Observation of the concentration trends at the site indicated that natural at-tenuation of DCP began in the 1990’s and continues to the current day. It appears from visual observation of the data plots that the data from diffusion sampling (the most recent 15 years of monitoring) closely follows a perceived attenuation trend. Data from the early site monitoring using bailed well technology appeared to deviate from the perceived attenuation trend.

An initial evaluation of the respec-tive sampling-technology specific datasets from nine wells was performed. Data suit-able for further evaluation was identified which exhibited the following characteris-tics: 1) Sufficient data points obtained via both sampling technologies, 2) A decreas-ing concentration trend, and 3) A concen-tration trend which could be closely fit via regression analysis. The datasets from two wells were determined to be suitable for evaluation of the variation of the results for

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each sampling technology from the mod-eled concentration trend.

The results of the evaluation indi-cated that a significant absolute error from concentration trend was present in the bailed well datasets when compared to the absolute error in the diffusion sampling datasets. However, the percent error calcu-lated for each technology indicates that is no significant different between the sam-pling technologies when not influenced by laboratory-induced error. The results con-firm that diffusion sampling is a viable technology for long-term monitoring of groundwater. Additionally, the results con-firm that the variability of low magnitude detections may be an artifact of laboratory-induced variability as theorized in 1998 and not attributed to sampling method in-duced variability.

Characterization and Imaging of Pipe Flow Within a Natural Em-bankment Bagbey, Daniel, dbagbey@g.clemson.edu, and Lawrence Murdoch, Department of Environmental Engineering and Earth Sci-ences, Clemson University, Clemson, SC Recent investigations have revealed a net-work of pipe-like conduits as much as 0.7 meters in diameter cutting into the base of a natural embankment in the Clemson Bot-toms. The embankment forms a natural dike between Lake Hartwell and the Bot-toms, and the pipes are approximately 10m below the lake level. The objective of this investigation is to characterize the pipe net-work and evaluate its role in controlling

flow through the embankment. The pipes are associated with 13 seeps, 9 of which produced a total flow rate of approximately 144 m3/day. Seepage rates varied with time and correlated to changes in the lake level. Water level fluctuations were rec-orded within the pipes during the spring and winter months using Hobo water level transducers. Comparing water level within the erosional conduits to that of Lake Hart-well shows a correlation between amount of flow within the erosional network and the stage of Lake Hartwell. The seepage flow varies with distance along the em-bankment, and with the greatest outflow and the largest visible conduits occur where the embankment is narrowest, and where the hydraulic gradient is the steep-est.

A camera survey was conducted in this region an effort to construct a detailed conceptual model of the pipes within the embankment. The survey also included a GoPro camera mounted on a remote con-trolled drone to take detailed areal photo-graphs of the area. These images were pro-cessed in Autodesk 360 to generate a 3D point cloud representation of the site. Us-ing known reference points in the areal photographs, imagery from within the con-duit network can be incorporated into the point cloud, generating a 360-degree, 3D representation of the erosional network and surficial site conditions from standard, 2D imagery. The 3D topographic data and the field observations will be integrated into a numerical model that will be used to evalu-ate the role of the pipes in groundwater flow through the embankment.

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The Applications and Limitations of Common Geophysical Methods in Determining Bedrock Depth Bergstrom, Jorgen, Jorgen.bergstrom@ gel.com, GEL Geophysics, Marietta, GA Having access to accurate and detailed depth to bedrock profiles and contour maps is of highest importance when investigating sites with DNAPL issues or when planned construction could be impacted by unantic-ipated bedrock. Traditionally, test borings are the primarily means to locate depth to competent bedrock. However, in situations with irregular bedrock surface, limited ac-cess for drill rigs, detached bedrock, or where drilling is considered hazardous, it is beneficial and important to incorporate ge-ophysical methods.

These methods typically enable continuous mapping of the bedrock sur-face, and can be used to detect partially weathered rock (PWR) as well as unweath-ered rock. The contact between PWR and unweathered rock is often important be-cause it likely marks an abrupt decrease downward in porosity and permeability and a hydraulic transition from predominantly intergranular flow above to fracture flow below. In situations with detached bedrock, geophysical methods can often be used to distinguish between bedrock and large boulders.

Some of the most common geo-physical techniques used in bedrock inves-tigations include seismic, resistivity, and ground penetrating radar (GPR) surveys. Seismic surveys operate on the principle of seismic wave propagation through the sub-grade with Multichannel Analysis of Sur-face Wave (MASW) and refraction surveys being the most common seismic survey methods being implemented. Resistivity

surveys assess the changes in electrical re-sistance of materials; these surveys use dif-ferent array settings, such as Wenner and Dipole-Dipole electrode configurations. The use of GPR is also an effective non-invasive technique that is deployed in areas with relatively shallow bedrock and favora-ble soil conditions.

These methods have become valua-ble tools for engineering and environmen-tal site investigation, but also have certain limitations that should be considered be-fore conducting any geophysical survey. The performance of any geophysical tech-nique is highly dependent on site factors. These factors include soil conditions, antic-ipated depth to bedrock, “noise” from out-side sources, the presence of utilities, and the site’s terrain. This presentation will fo-cus on case studies where geophysical methods were used for bedrock mapping, and discuss advantages and shortcomings.

The Influence of Slope on the Weathering Rates of Biotite Gneiss Bedrock Berisford, Jordan, Jberisf@ g.clemson.edu, and Scott Brame, Environ-mental Engineering and Earth Science, Clemson University, Clemson, SC Making correlations between map units in the Piedmont region of South Carolina can be difficult due to the lack of outcrop away from stream bottoms and road cuts. This study investigated the potential of identify-ing rock type in the absence of outcrop from an analysis of soil cores in an area with moderately steep topography. Previ-ous mapping had verified that the site is underlain predominately by biotite gneiss.

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The goals of this study were to (a) deter-mine the potential of using hand coring tools to identify bedrock in the absence of outcrop and (b) assess the influence of slope change on the relative weathering rates of minerals present on the parent rock. Analysis of the weathering byprod-ucts was used to infer the original minerals present.

Soil cores were collected at discrete locations on a hillside using an AMS ham-mer and a 2.22 cm soil recovery probe. The average depth of core collected was 304.8 cm. The hillside is characterized by two dominant slope angles. At the bottom of the hill, a 23o slope is present where the stream had over-steepened the hillside on the side of a small flood plain. About 12.5 meters up the hill from the floodplain the slope angle changes to 15o until it reaches the crest of the hill.

Soil samples were analyzed using XRD to determine the weathering byprod-ucts. Results showed that vermiculite, a weathering byproduct of biotite, was pre-dominate at a depth of 2.1 meters and be-low over the entire hillside. Kaolinite, a weathering byproduct of feldspar, was found at a depth of 0.6 meters on the gentle slope and a depth of 1.8 meters on the steeper slope. Non-weathered biotite was found at a depth between 0.3 meters and 0.9 meters on the gentle slope and at a depth of 1.8 meters on the steeper slope. The results indicate that this method has potential as a mapping technique using a basic knowledge of weathering byproducts. The comparison of the two slope types re-vealed that the steeper slope has a higher weathering rate compared to the gentle slope.

Estimation of PCB Contamination in the Twelve Mile Creek Arm of Lake Hartwell, SC, using GIS and Statistical Techniques Bharadwaj, Arjun, Cindy Lee, Scott Brame, and Anthony Herrman, Depart-ment of Environmental Engineering and Earth Sciences, Clemson University, Clem-son, SC Lake Hartwell and its Twelve Mile Creek watershed were contaminated with poly-chlorinated biphenyls (PCBs), mainly Aro-clor 1016 and 1254, which resulted in a designation as a Superfund site. The Twelve Mile Creek arm is the most heavily contaminated portion of the lake. A fish advisory has been in place since the late 1970s. Natural attenuation, primarily through burial by uncontaminated sedi-ment, was the chosen remedy. Several studies have aimed at understanding the concentrations of PCBs in the sediments and the time required to the lifting of the fish advisory. Our study focuses on docu-menting results of previous and current contamination levels by geographic infor-mation system (GIS) modeling and predict-ing when the target sediment concentra-tions will be reached through statistical techniques. Results from historic and cur-rent sampling are consolidated into a GIS base map. Particle size analysis and gas chromatography are combined to provide PCB concentrations in samples collected in 2014-2015. Kriging and inverse distance weighting interpolation (IDW) in ArcGIS are used to estimate PCB concentrations in areas of the lake arm that have not been sampled. Regression analysis, validated through the current sampling, allows pre-dictions of when sediment concentrations

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will reach target levels for removal of the fish advisory. Inclusion of Faults in 3-D Numeri-cal Simulation of Carbon Dioxide Injection into the South Georgia Rift Basin, South Carolina Brantley, D1, brantley@esri.sc.edu, J. Shafer2, V. Lakshmi3, and M. Waddell1 1Earth Sciences and Resources Institute, University of South Carolina, Columbia, South Carolina 2Sundance Environmental and Energy Spe-cialists, Ltd. Columbia, South Carolina 3Department of Earth and Ocean Sciences, University of South Carolina, Columbia, South Carolina This paper reviews the effects of faulting on the numerical simulation of CO2 injec-tion into the South Georgia Rift (SGR) ba-sin. The SGR basin is the southernmost rift basin along the Eastern North American Rift System (ENARS) and is comprised of Triassic and Early Jurassic continent de-rived fluvial and lacustrine sandstone, silt-stone and mudstones intercalated with lay-ers of basalt and/or diabase. The focus of this research is to use a 3-D geologic model that includes geologic structure and fault-ing to better analyze the impact of these features on the ultimate fate of injected CO2. Newly acquired SGR basin data has revealed that the basin is a highly fractured and faulted basin; therefore, the effect of the faulting on CO2 migration must be con-sidered when determining the efficacy of geologic storage of CO2 in this basin. Pet-rel™ was used to construct the 3-D geolog-ic model and this model was imported into

CMG-GEM™ compositional reservoir simulator for CO2 injection simulation. Total simulation time was 100 years during which a total of 30 million tonnes of CO2 was injected at a rate of 1 million tonnes per year for 30 years followed by a 70 year shut-in period. Multiple experiments were run to find the effects of fault permeability on the resultant fate of the injected CO2. Fault permeabilities reviewed in this paper are: 0 mD representing a sealing fault, 1 mD representing a low permeability fault, and 100 mD representing a conduit fault. The results illustrate that with a permeabil-ity of 1 mD, significant leakage of CO2 oc-curs up the faults. This is evidence that fault analysis is a critical factor in injection simulation modeling and that even low per-meability faults make the geology poten-tially unsuitable for long term geologic storage of CO2.

Geochemical Modeling for Reme-dial Alternatives Analysis of Acid Mine Drainage at the Henry Knob Former Mine Site Bruce, Christopher H., Christopher. bruce@amec.com, AMEC, Greenville, SC, A. Mikszewski, AMEC, Durham, NC, N. Kresic, AMEC, Kennesaw, GA The Henry Knob Former Mine Site is lo-cated in the Piedmont region of South Car-olina and was used for mining kyanite. Oxidation of pyrite in a large mine pit (MP) and tailings areas have created classic acid mine drainage conditions, causing acidity (low pH), cobalt, and manganese

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impacts to groundwater and residential wa-ter supply wells adjacent to the mine.

A numerical groundwater flow model was developed and calibrated to es-tablish regional boundary conditions and evaluate interactions between the MP pond and surrounding groundwater. The region-al model was used to perform fate and transport (F&T) simulations for metals based on site-specific Kd values. Simula-tions indicate that the metals of concern have limited mobility due to the high cal-culated Kd values.

A focused (telescoped) groundwa-ter model for the areas in and around the MP and tailings areas was developed using boundary conditions and calculated heads from the regional model. This telescoped model was used to perform reactive simu-lations of pH transport using PHT3D based on mineralogy and geochemical groundwa-ter data. The model was used to assess the efficacy of the following remedial options 1) excavation and off-site disposal of tail-ings, and grading/vegetating the excavated areas; 2) capping the tailings with a geo-synthetic cover; 3) establishing a vegeta-tive cover; above tailings areas and 4) con-solidating the tailings into the MP and cap-ping with a geosynthetic cover. Remedial alternatives were evaluated based on their ability to increase pH in and around areas of concern, including streams and residen-tial wells.

Case Study: Gravity Fed ISCO In-jection for DNAPL Treatment in a Perched Water Zone Byrd, Jennifer, jennifer.byrd@erm.com, and Jeff Bilkert, Environmental Resources Management, Atlanta, Georgia

Volatile Organic Compounds (VOCs) have been identified in groundwater at a former manufacturing facility in Alabama. The primary contaminant of concern is Trichlo-roethene (TCE). TCE has been observed on-site at concentrations approaching 50% of saturation (i.e. 500,000 ppb). Based on these concentrations, it is assumed dense non-aqueous phase liquid (DNAPL) is pre-sent in the subsurface, although no DNAPL has been observed in groundwater or soil cores during recent investigation activities.

Although high source area concen-trations of TCE are present, the extent of the source area and the overall contaminant plume is limited, which is primarily due to the site-specific geology. A perched water zone is located beneath the former manu-facturing building at 5 to 15 feet below ground surface (bgs) and extends to a depth of approximately 40 feet below bgs. The perched water zone is underlain by a clay semi-confining layer. An unsaturated zone roughly 5 and 10 feet thick is located be-tween the semi-confining clay unit and the underlying aquifer. The contaminant mass is almost completely limited to the perched water zone. Contaminant concentrations in the underlying aquifer are several orders of magnitude less than those observed in the perched water zone (i.e. less than 200 ppb of TCE).

Two primary source areas have been identified on-site. The first is located in a portion of the perched water zone with low hydraulic conductivity. Lithology in this area consists of tight expanding clays. The second source area is located in a por-tion of the identified perched water zone that has relatively higher hydraulic conduc-tivity. Lithology in this area consists of more permeable silty clays. In both source areas, TCE is observed at concentrations in a range indicative of the presence of DNAPL (i.e. 500,000 ppb). In both source

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zones, however, TCE concentrations de-crease laterally to less than 5,000 ppb with-in 50 feet.

The primary remedial objective at this time is to address the small areas of high concentration contamination located in the perched water zone. In situ chemical oxidation (ISCO) was selected for pilot testing in the two source areas. ISCO is not typically a cost competitive solution when dealing with DNAPL range concen-trations due to required repeated applica-tions. At this site, however, the depth of the contaminant mass and the area requir-ing treatment allowed for cost effective re-curring oxidant injection. Pilot test pres-surized injection of 10% by weight sodium permanganate solution was conducted in one of the two source areas. Significant back pressure along with limited daylight-ing was observed during the injection. Due to oxidant delivery challenges encountered during the pressurized pilot test injection, a gravity feed infrastructure was constructed to allow for frequent oxidant application to the two source areas. Two pilot test gravi-ty feed injections of 5% by weight sodium permanganate solution have been complet-ed in each source zone.

Within four months following the first gravity fed pilot test injection, oxidant in the more permeable source zone has been completely consumed in both the monitoring points and injection wells. TCE concentrations in this area of the site have decreased by 80% in response to IS-CO treatment. Based on experience at other sites, contaminant rebound is expected, but has not been observed to date. Adequate oxidant distribution in the less permeable source area zone via gravity feed delivery methods has been more challenging. Alter-native methods of distributing oxidant throughout the perched zone are being field

tested and will be discussed during the presentation.

Refinement of the Seneca Fault in the Southwest Corner of the Six Mile Quadrangle Caldwell, G. Storm, gcaldwe@ g.clemson.edu, and Scott Brame, Depart-ment of Engineering and Earth Sciences, Clemson University, Clemson, South Caro-lina

A portion of the Six Mile Quadrangle was reevaluated in order to update previous maps with regard to the exact location of the Seneca Fault. The main objective was to be able to recognize the lithologic transi-tions from the Six Mile thrust sheet (hanging wall) to the Walhalla Nappe (footwall) and to determine the exact trace of the fault. This area contains three dis-tinct rock types: the Talluah Falls For-mation, the Table Rock Gneiss, and a horn-blende gneiss. Previous mapping by Grif-fin (1974) and Garihan (2005) had assigned the Tallulah Falls Formation to the Six Mile Thrust Sheet and the other two units to the Walhalla Nappe.

The study consisted of east-west traverses of streams, collecting samples, and an analysis of hand samples and thin sections. It was determined that the Seneca Fault lies in a range of 0 to approximately 1000 meters further east than previously reported by Griffin.

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Development of a Groundwater-Flow Model of the Atlantic Coastal Plain, Aiken County, South Caro-lina Campbell, Bruce G., bcampbel@ usgs.gov, and James E. Landmeyer, U.S. Geological Survey, South Atlantic Water Science Center, Columbia, South Carolina Aiken County is located along the Fall Line, bordered by the Savannah River to the west, Edgefield and Saluda Counties to the north, Barnwell and Orangeburg Coun-ties to the southeast, and by Lexington County to the east. The population between 2000 and 2014 increased by about 14 per-cent, to about 165,000 persons, and is an-ticipated to experience similar growth in the near future. Aiken County is the fourth largest county in South Carolina being about 1,073 square miles.

Most of the potable water supply for Aiken County, with the exception of North Augusta, is supplied by groundwater pumped from the multiple Atlantic Coastal Plain (ACP) aquifers that underlie most of the county. The ACP aquifers are very pro-ductive and generally contain high-quality groundwater that require little treatment prior to use, although some wells experi-ence water-quality degradation due to high levels of iron. The reliance on groundwater by Aiken County has increased steadily since the 1950’s, but it is unknown if these increasing withdrawals of groundwater will affect the current or future availability or quality of groundwater in Aiken County. To compound this uncertainty, there is a recent trend in the expansion of acreage in the County where groundwater is used con-sumptively for agricultural irrigation. The effect of this withdrawal of groundwater for irrigation uses on the resource and im-

pact on potable supplies is unknown. The primary objective of the devel-

opment of the groundwater-flow model of Aiken County is to develop a living model that can be used by Aiken County water utilities or others to manage current and projected reported and unreported demands on groundwater resource. The model will be used to calculate the water budget for the Aiken County area, and to facilitate the estimation of capture zones for wells. The model framework is currently being com-piled.

Why Map Contaminant Concen-tration Only? – The Importance of Flux Measurement using Real Time Measurement Systems Carlson, Brad, wcarlson@ zebratechservices.com, Zebra Technical Services, Tampa, FL and William M. Da-vis, wmdavis@triad-env.com, Triad Envi-ronmental Solutions, Inc, Durham, NC The objective of data collection during site characterization is to provide decision makers with data of sufficient quantity and quality to allow definitive decisions on re-medial actions. Recent advances in tools for the collection of high density hydro-stratigraphy and high density soil and groundwater contaminant data have al-lowed implementation of cost effective strategies for mapping contaminant flux in high resolution.

One of the key requirements for successful high density site characteriza-tion projects is a reliable real-time field analysis for the contaminants and matrices of concern. Data required to understand contaminant flux include local geologic and hydrogeologic conditions as well as

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contaminant distribution in groundwater and bulk phase soil. This presentation will discuss the tools currently available to col-lect data to allow an understanding of flux at sites at the scale required to design and implement remedial actions.

Characterizing Bedrock and Re-sidual Soil Conditions with MASW and ERI Daniel, Joel, jdaniel@schnabel-eng.com, and J. W. Whitt, Schnabel Engineering, Greensboro, NC Evaluating potential groundwater and con-taminant flow pathways in crystalline rock and residual soil environments typically requires a thorough characterization of sub-surface geologic conditions. The level of characterization needed is often dictated by contaminant characteristics, regulatory re-quirements, and cleanup goals. The ability to successfully characterize a site is usually governed by cost and site access condi-tions, particularly in developed areas.

Detailed subsurface characteriza-tion of such sites by invasive methods alone can be cost prohibitive, and signifi-cant geologic features may be missed en-tirely by invasive methods if their presence is unforeseen. In addition, the detailed characterization of developed sites may not be possible due to limitations on ground disturbance, and the presence of paved sur-faces and buried utilities.

Geophysical methods can provide a rapid, cost-effective means of supplement-ing limited site characterization data ob-tained by invasive means. In particular, the electrical resistivity imaging (ERI) method and the multichannel analysis of surface

waves (MASW) method are often success-ful in evaluating bedrock weathering pro-files and fracture zones, even at developed sites. Several examples of such applica-tions will be presented.

Tensor Strainmeter and Vector Tiltmeter Design for Measuring Ground Deformations Associated with Fluid Injection and/or With-drawal DeWolf, Scott1, sdewolf@clemson.edu, Larry Murdoch1, Stephen Moysey1, Leo-nid Germanovich2, Alexander Hanna1, and Josh Smith2 1 Department of Environmental Engineer-ing and Earth Sciences, Clemson Universi-ty, Clemson, South Carolina 2 School of Civil and Environmental Engi-neering, Georgia Institute of Technology, Atlanta, Georgia Injecting fluids into a well deforms the en-veloping rocks in a complex pattern that increases in magnitude and expands out-ward with time. While this evolving strain field creates space needed to store these fluids, it can also signal problems. Fault slip occurs when stresses caused by injec-tion reach a critical value, and maintaining stresses below a critical stress state is im-portant for limiting the risk of faulting and subsequent leakage. Since it is impossible to measure stresses directly, the approach is to measure displacement or strain, and then calculate stress change. The geodetic research community has developed bore-hole strainmeters capable of measuring the horizontal strain tensor with high resolu-tion (>1 nanostrain), but these require per-manent installation and are far too expen-

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sive to be abandoned after short term stud-ies.

We will present some design details and preliminary lab tests of a far less ex-pensive, removable instrument capable of measuring four components of strain and two components of tilt. Each sensing com-ponent employs non-contact eddy current transducers capable of measuring nanome-ter displacements. While not as precise as permanent borehole instruments, this new removable system should be able to resolve ground deformations associated with 0.5 to 1 microstrain per day rates expected at a proposed CO2 injection site. This system should also be well-suited for aquifer mon-itoring as well as for some geophysical sig-nals.

Development of a Practical Ap-proach for Modeling Matrix Diffu-sion Effects in Groundwater Transport Models Falta, Ronald W., faltar@clemson.edu, Environmental Engineering and Earth Sci-ences, Clemson University, Clemson, SC Matrix diffusion occurs when groundwater contaminants present in high permeability zones diffuse into adjacent low-permeability zones. This process occurs in a variety of geologic settings including simple aquifer-aquitard systems, layered systems, strongly heterogeneous systems, and fractured porous media. In all cases, the contaminants that have diffused into the low permeability zones can represent a long term source of contamination follow-ing remediation of the high permeability zones due to the phenomena of back diffu-sion.

Current numerical modeling ap-proaches are not able to accurately resolve the local-scale matrix diffusion effects without resorting to extremely fine grids, with gridblocks numbering in the millions. We are developing an alternative approach that uses analytical approximations inside each normal (large) gridblock to represent the local-scale matrix diffusion. This method was originally developed in the geothermal reservoir modeling field for simulating transient heat conduction in low permeability cap rocks. With this method, only the high permeability zone is discre-tized in the numerical model, and the inter-action with the low permeability zone is accounted for in a time-dependent source/sink term that is computed analytically in each gridblock.

The new method is extremely effi-cient, and it compares well with exact ana-lytical solutions for diffusion into and out of clay aquitards. The method is also ap-plicable to general layered or heterogenous media, as well as fractured porous media.

Developing the U.S. Geological Survey StreamStats Web Applica-tion for South Carolina Feaster, Toby D., tfeaster@usgs.gov, U.S. Geological Survey, Clemson, SC; and Jimmy M. Clark, U.S. Geological Survey, Columbia, S.C. Government agencies, engineers, scientists, water-resources managers, and others use streamflow statistics for the purposes of water management, permitting, and infra-structure design. Examples of such stream-flow statistics are the 1-percent chance flood (also referred to as the 100-year

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flood), the mean annual flow, and the an-nual minimum 7-day average streamflow with a 10-year recurrence interval. These statistics can be computed for locations where streamflow data are collected, such as at U.S. Geological Survey (USGS) streamgages. However, financial and hu-man-resource limitations make it impossi-ble to collect data everywhere streamflow statistics may be needed, which are often are ungaged locations where no streamflow data are available.

To address the needs of entities re-quiring streamflow information, the USGS, in cooperation with Environmental Sys-tems Research Institute, Inc., developed a web-based application called StreamStats that serves published streamflow statistics to the public and facilitates the estimation of streamflow statistics for ungaged sites on streams (http://water.usgs.gov/osw/streamstats/index.html). StreamStats is an integrated web-based geographic infor-mation system (GIS) application that makes the process of computing stream-flow statistics for ungaged sites faster, more accurate, and more consistent than previous methods.

StreamStats allows a user to select any point on a stream through a web-based interactive map and delineate the contrib-uting drainage area to that point. Once the user confirms the basin boundary, Stream-Stats identifies any regional USGS equa-tions that are available for the basin, com-putes the required basin characteristics, and uses them in the equations needed to com-pute the streamflow statistics. Additionally, a report containing the computed basin-characteristic values and streamflow statis-tics is generated. StreamStats also provides an option to download a shapefile of the drainage boundary that can be imported into a local GIS. The shapefile includes the computed basin characteristics and stream-

flow statistics as attributes. The USGS, in cooperation with the

South Carolina Department of Transporta-tion, has developed plans to implement the StreamStats web application in South Car-olina. In October 2014, application devel-opment and implementation of StreamStats will begin. When completed, the applica-tion will include regression equations to estimate flood-frequency flows at rural and urban ungaged locations along with the ba-sin characteristics needed to compute those estimates. The StreamStats database also will include low-flow frequency statistics published by the USGS. Additionally, field measurements of historic bridge scour in South Carolina and USGS historic indirect flow measurements will be incorporated into the South Carolina StreamStats appli-cation. It is anticipated that the project will be completed by April 2018.

Comparative Study of Soil CO2 Flux using Eddy Covariance and Chamber Methods George, Shanay, shanayg@g.clemson.edu, and Scott Brame, Department of Environ-mental Engineering and Earth Sciences, Clemson University, Clemson, South Caro-lina. The Eddy Covariance (EC) technique can be used to measure and calculate carbon dioxide fluxes from land and areas covered by water. This method relies on precise measurements of turbulent vertical fluxes within atmospheric boundary layers. This study used this method to measure CO2 fluxes in the Bottoms area of the Clemson Agricultural Farms adjacent to an

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undammed reach of the Seneca River. We used a 10 foot high pole mounted with a Gill Propeller Anemometer and an infrared CO2 meter. The anemometer was mounted such that is only recorded vertical wind speed. Each device continuously measured data and took samples every 5 seconds. These measurements were used to calculate an averaged carbon dioxide flux from the surrounding agricultural fields. These re-sults were compared with values obtained with the chamber method of determining CO2 flux. The EC method showed that car-bon dioxide fluxes results were similar to the chamber method.

Comparison Study of Multiple Groundwater Sampling Tech-niques in Fractured Bedrock Hanley, David, Michael Patinkin, mpatinkin@ geosyntec.com, and Jeff Ahrens, Geosyntec Con-sultants, Charlotte, NC; and Todd Hagemeyer, Geosyntec Consultants, Kennesaw, GA

The Carolawn Superfund Site (Carolawn) in South Carolina is a former waste storage and disposal facility which operated from 1970 to 1979. Following Site abandon-ment, EPA conducted removal actions, which have been followed by three decades of assessment and remedial efforts includ-ing: groundwater pump and treat, an en-hanced in-situ biodegradation pilot study and soil vapor extraction (SVE). The cur-rent Site setting is a remote and wooded area with a roughly ¼-mile long and rela-tively dilute plume (maximum concentra-tion of approximately 500 micrograms per liter [µg/L] or less) of chlorinated volatile organic compounds (cVOCs) residing in a fractured bedrock system.

Geosyntec has provided support to conceptual site model (CSM) development,

remedial design of the SVE system, and on-going groundwater monitoring services at the Site since 2013. For over twenty years prior, groundwater samples have been col-lected at the Site on a semi-annual basis using traditional well purge volume sam-pling methods. This approach encumbered a significant time investment, generation of significant volumes of investigation-derived wastes (IDW, over 2,000 gallons per event), and associated costs. In an ef-fort to streamline sampling efforts, Geo-syntec conducted a field comparison study to evaluate alternative groundwater sam-pling techniques with the objective of providing high-quality, representative data at a lower cost and effort. Low-purge vol-ume sampling and passive diffusion bag (PDB) sampling, which have both gained significant regulatory acceptance in recent years, were evaluated as alternative meth-ods to the traditional well purge volume approach.

In this comparison study, Geosyn-tec collected groundwater samples using three sampling methods from a group of fifteen monitoring wells with a representa-tive range of open borehole lengths in frac-tured bedrock (15 to 130 ft in length). The well group included a representative range of Site groundwater VOC concentrations. Also, vertical mixing/variation were evalu-ated through the deployment of multi-depth PDBs within a single borehole.

Geosyntec’s evaluation effectively demonstrated that the PDB sampling tech-nology can provide VOC data representa-tive of aquifer conditions at each monitor-ing well based on a side-by-side compari-son with well-purge sample results with consideration to current site conditions and historical groundwater trends. Additional-ly, the PDB sampling method generates the smallest volume of IDW, using the lowest sampling effort, at the lowest cost com-

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pared to the alternatives. These combined advantages were recognized by the EPA in their approval of PDBs for future sampling efforts at the Site.

Using Geomechanical Meas-urements for Subsurface Char-acterization Hanna, Alexander C., achanna@ g.clemson.edu, Stephen M.J. Moysey, and Lawrence C. Murdoch, Environmental Engineering and Earth Sciences, Clemson University, Clemson, SC Carbon sequestration is one proposed method of reducing greenhouse gas emis-sions in order to mitigate the effect of car-bon dioxide on climate change processes, ocean acidification and human health. Car-bon injection is the process of capturing carbon dioxide, compressing it into a super-critical fluid, and injecting it at high pres-sures into a deep, hydraulically confined geologic structure such as a saline aquifer, coal bed or depleted oil or natural gas res-ervoir. This method introduces several risk-assessment challenges. These include the leakage and escape of carbon dioxide, the reactivation of dormant faults, topographic subsidence/uplift, or contamination of ex-isting groundwater resources. In order to mitigate these risks, careful site assessment and monitoring of carbon sequestration projects is necessary.

Geomechanical instruments such as pressure gauges, tilt meters and strain me-ters can be used to assess the poroelastic response of an aquifer to the stress of this high pressure injection process. Using a poroelastic numerical model and a set of

stochastic optimization algorithms, we have developed a technique to use these geomechanical signals to characterize the mechanical and hydrogeologic parameters of the subsurface. As this approach re-quires a large number of poroelastic simu-lations, we use the Palmetto supercomputer to distribute computational effort over a large number of computational nodes.

Our numerical results indicate that strain measurements are more informative than tilt measurements, and that when com-bined these data types are capable of simul-taneously solving for the Young’s modu-lus, Poisson ratio, permeability, porosity, and Biot-Willis coefficient of a homogene-ous formation. We also observe that meas-urements taken with the confining unit are capable of estimating poroelastic parame-ters with a similar degree of precision as measurements taken from inside the target formation. This finding allows us to char-acterize a target formation without the risk of puncturing the confining unit.

Sediment Core Characterization in the Twelvemile Creek Arm of Lake Hartwell, SC Herrmann, Anthony, ajherrm@ clemson.edu, Scott Brame, and Arjun Bharadwaj, Department of Environmental Engineering and Earth Sciences, Clemson University, Clemson, South Carolina Twelvemile Creek, a tributary for Lake Hartwell in the Upstate of South Carolina, was contaminated with PCBs between 1955 and 1987 by Sangamo-Weston, Inc. To correct this problem, two of the three dams on Twelvemile Creek were removed in 2011 to allow the release of sediment to

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the lake. The goal of that effort was to cover up the contaminated sediments and prevent the PCBs from becoming bioavail-able.

In this study, sediment cores were collected between October 2014 and Janu-ary 2015 in order to evaluate the sediment distribution in the lake. Core samples were taken using a custom built coring rig, which utilized the mating of an aluminum canoe and a 14 foot v-hull johnboat. These two vessels were attached together using a plywood frame to provide a stable platform for coring activities. A heavy duty tripod was mounted on the platform to retrieve core samples in highly compacted sedi-ments.

Core samples were collected at sev-eral locations across a transect of the Twelvemile Creek channel. The goal was to core all the way to saprolite to determine sediment distributions that had occurred since Lake Hartwell was dammed (1963), but this was not always possible due to col-lapse of the core holes in sand formations between sampling. Within this transect, it was found that sediments on either side of the channel were between 1.2 and 1.6 me-ters deep. The midpoint of the transect, which fell within the channel, yielded little useable data because it’s high sand content prevented deep coring.

Sediment type and thickness data were plotted using the geologic modeling module of GMS (Groundwater Modeling System). Coring data was used to construct cross sections by correlating changes in thickness and sediment type. This analysis indicates that sedimentation in the Twelvemile Creek Arm of Lake Hartwell is occurring slowly on the edges of the creek, compared to the middle of the channel which was mostly sand.

Chemical Fixation of Priority Heavy Metals in Soil, Sediment and Groundwater using MetaFix™ Reagents Hicks, Patrick, Patrick.hicks@ peroxychem.com, Fayaz Lakhwala, and Alan Seech, PeroxyChem, Philadelphia, PA High concentrations of heavy metals are found in many soil and sediment environ-ments. At very high concentrations, heavy metals are known to create toxicity to mi-croorganisms. Treatment approaches that rely on microbial process may not function well in an acutely toxic matrix because im-portant processes such as carbon fermenta-tion, oxygen consumption, and biological sulfate reduction can be significantly slowed or completely inhibited. The under-standing of many metals removal mecha-nisms operative in soil and groundwater has advanced significantly over the past decade – thus, we are now in a better posi-tion to develop a new platform of effective metal remediation products.

Hence, in toxic environments, treat-ment reagents that do not depend entirely on microbial activity but rather combine reduction with adsorption and precipitation of heavy metals are advantageous. Meta-FixTM reagents represent an entirely new family of products for treatment of soil, sediment, industrial wastes, and groundwa-ter contaminated with heavy metals. Treat-ment mechanisms based on iron, iron sul-fides, and other iron-bearing minerals have significant advantages due to lower solubil-ity and greater stability of iron-bearing mineral precipitates formed with heavy metals. The new reagents enrich the aquifer with a mixture of reducing agents (ZVI, iron sulfides) and processed reactive min-

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erals (iron oxides and iron oxyhydroxides). This new approach is insensitive to toxicity and will perform well even in environ-ments that have high metals concentrations, high concentrations of organic contami-nants such as solvents, high salt content, or pH levels (high or low) that would inhibit carbon fermentation and sulfate reduction.

The approach used in these new reagents is to create an effective blend of reducing agents, reactive minerals, mineral activators, catalysts, pH modifiers, and ad-sorbents for either ex-situ or in situ appli-cations. Dredge spoils containing high lev-els of TCLP/SPLP metals can be quickly treated and stabilized before final disposal. In situ reactive zones can be constructed to prevent migration of heavy metals into sed-iments or surface water. MetaFix reagents can also be directly delivered into sedi-ments for in situ stabilization of heavy met-als and thereby reduce exposure to aquatic life. Laboratory results showing reduction in TCLP and SPLP of key metals will be presented.

Comparison of Air Sparge/ Soil Vapor Extraction Pilot Tests from Four Chlorinated Ethene Impact-ed Sites in Distinct Geologic Set-tings of the Piedmont Hollifield, Edward, ed.hollifield@ erm.com, Environmental Resources Man-agement, Charlotte, North Carolina, and Joshua Fell, Environmental Resources Management, Raleigh, North Carolina The presentation will compare and contrast conditions and results from air sparge / soil vapor extraction (AS/SVE) pilot tests at four project sites located in widely varied

geologic settings of the Piedmont of North and South Carolina. Following RI/FS activ-ities at each site, AS/SVE was selected as a potential remedial technology to treat chlo-rinated ethenes in soil and groundwater. Objectives of the pilot testing were to eval-uate the efficacy of AS/SVE as individual and combined remedial technologies and to determine suitable design and operational criteria for full-scale implementation in the four disparate site geologic settings.

Desired pilot test results included: 1) achievable air extraction rates from an SVE well under a given vacuum; 2) sub-surface vacuum rates at varying distances from an SVE well to evaluate the zone of vacuum influence; 3) estimates of the VOC emissions that initially occur through the use of an SVE system; 4) concentrations of VOCs in extracted vapors with time during the test and after SVE pilot testing stage ceases; 5) achievable air injection rates from an AS system under a given pressure; 6) groundwater dissolved oxygen and po-tential mounding at varying distances from the air sparge well; and lastly 7) a measure of the VOC emissions with the introduction of air sparging. Although design proce-dures were similar at each site, the pilot testing was conducted in widely differing Piedmont geologic settings including silty saprolite, weathered argillite with near ver-tical joints, and highly fractured metamor-phosed bedrock. While each site setting presented challenges that resulted in widely varying responses, it is reasonably ex-pected that in similar site conditions, AS/SVE would yield similar results.

Pilot test procedures at each site included the installation of AS/SVE wells and associated observation wells, baseline soil vapor and groundwater sampling, and then conducting at a minimum, a four stage test with increasing SVE and AS rates and associated sampling for the desired param-

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eters. In addition to the above procedures, pneumatic fracturing was employed at one site between two pilot tests to evaluate if fracturing enhanced the AS/SVE perfor-mance and VOC removal rates. Another of the pilot tests was conducted in a multi-zone setting consisting of an upper and lower treatment area requiring a six stage test. The remaining two pilot tests followed the standard procedures with one being conducted in the typical saprolitic Pied-mont aquifer zone and one being conducted in highly fractured dioritic bedrock.

While three of the site settings may not traditionally be considered ideal for implementing a full-scale AS/SVE remedy to treat chlorinated ethenes, pilot testing demonstrated that this proven remedial technology can be applied under natural or enhanced subsurface conditions in these settings and is capable of achieving posi-tive long term reduction in contaminant concentrations with moderate costs. The presentation will provide details of the pilot test designs, field activities, and the results of each test with a summary of lessons learned.

Water Characteristics Affecting Photo-catalytic Oxidation of Com-mercial Naphthenic Acids Kiekhaefer, R.L.1 rkiekha@clemson.edu, A.D. McQueen2, C.M. Kinley2, J.W. Cas-tle1, and J.H. Rodgers Jr.1 1Environmental Engineering and Earth Sci-ences, Clemson University Clemson, SC 2Forestry and Environmental Sciences, Clemson University Clemson, SC Naphthenic acids (NAs) are a complex group of organic acids that occur naturally

in petroleum deposits such as the Athabas-ca oil sands in Alberta, Canada. Bitumen is extracted from sandy deposits using a mixture of hot water and caustic soda. This process causes NAs to separate from the bitumen and dissolve into the water. The water is held in large ponds on site and cannot be discharged without treatment. A novel treatment option available to mitigate the risks of NA includes photo-catalytic degradation. The aim of this study was to determine the potential effects of water characteristics on the degradation rates and extents of commercial NAs following pho-to-catalytic oxidation treatments using tita-nium dioxide (TiO2) as the catalyst. To achieve this, the specific water characteris-tics investigated included depth, turbidity, pH, DO, temperature, recirculation, and concentrations of constituents such as met-als, salts, and organic acids (other than NAs).

Bench scale photo-catalytic treat-ments were conducted using a thin film and slurry application of the catalyst, under nat-ural sunlight or a UV-C lamp irradiation (depending on the requirements of each treatment). Naphthenic acid concentrations were measured hourly over a 7 hour expo-sure in order to measure the degradation rate and efficiency of NA removal for each treatment. Preliminary results indicate the removal of NAs by photo-catalytic oxida-tion follows first order kinetics; CNA = CNA0e

-kt, where CNA is the concentration of NAs at time t, CNA0 is the initial NA con-centration, and k is the rate constant (hr-1). Rate constants were calculated for each treatment and compared to one another in order to determine the effects of water characteristics.

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Assessment of Groundwater Quali-ty of Atlantic Coastal Plain Aqui-fers, Aiken County, South Carolina Landmeyer, James E., jlandmey@ usgs.gov, and Bruce G. Campbell, U.S. Geological Survey, South Atlantic Water Science Center, Columbia, South Carolina Groundwater pumped from the Atlantic Coastal Plain (ACP) aquifers meets most of the potable and irrigation demands for Ai-ken County, but a comprehensive assess-ment of groundwater-quality conditions for Aiken County does not exist. This lack of an assessment of groundwater-quality con-ditions, even basic indicators such as pH, temperature, and dissolved oxygen, pre-cludes County water managers and others from making informed decisions about where to place new wells (e.g., avoid areas where groundwater may contain high iron or radium isotope concentrations), how deep to drill wells, and what depth intervals should be screened to avoid in-well mixing of groundwater of different reduction/oxidation (redox) characteristics. As such, a comprehensive compilation of groundwa-ter-quality data for Aiken County would be useful to water managers that want to mini-mize costs associated with groundwater treatment or others interested in groundwa-ter quality.

In Fiscal Year 2015, the U.S. Geo-logical Survey (USGS), in cooperation with Aiken County, Breezy Hill Water and Sewer Company, Inc., Gilbert-Summit Ru-ral Water District, and Montmorenci-Couchton Water and Sewer District, started a 3-year project to investigate the availabil-ity of the groundwater resources of Aiken County. A major component of the project is to develop a groundwater-flow model of the ACP beneath Aiken County. Because

groundwater availability is dependent upon water quality and water-quality characteris-tics can be useful during model calibration, we plan to provide this data in two ways. First, existing water-quality data will be compiled, and second, we will sample mul-tiple public-supply wells across the County for basic physical properties and chemical composition of the groundwater. At select wells, additional water-quality parameters, such as inorganics, radionuclides, and vola-tile organic compounds, also will be sam-pled and analyzed. Because the project is just getting started, the presentation will primarily focus on previously existing groundwater-quality data.

2-Dimensional Geophysical Imag-ing of Infiltration in a Homoge-nous Medium Lytle, Blake, balytle@clemson.edu, De-partment of Environmental Engineering and Earth Sciences, Clemson University, Clemson, South Carolina An infiltration experiment was performed in a sand-filled tank and monitored with time-lapse reflection ground penetrating radar (GPR). Replicate profiles were rec-orded in the same location during irrigation of the sand by use of an automated gantry system to rapidly position the antennas. Data were collected as common midpoint profiles (CMP’s) to obtain subsurface ve-locity information as well as common off-set profiles (COP’s) to monitor the spatial and temporal changes of reflected arrivals throughout infiltration. The data show in-teresting patterns accompanying wetting of the soil and propagation of the wetting front during the experiment. The patterns are interpreted as indication of non-

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uniform movement of the wetting front. EM wave velocity was determined by ana-lyzing the normal moveout (NMO) of a static reflector. Additionally, changes in traveltime to a specific arrival in the COP’s were tracked to estimate spatial changes in velocity. The velocity information was used to migrate the data, resulting in imag-es of infiltration with depth.

Automated High-resolution GPR Data Collection for Monitoring Dynamic Hydrologic Processes in Two and Three dimensions Mangel, Adam, amangel@clemson.edu, Blake A. Lytle, and Stephen Moysey, De-partment of Environmental Engineering and Earth Sciences, Clemson University, Clemson, SC Ground penetrating radar (GPR) has be-come a popular tool for monitoring near surface hydrology. Specifically, time-lapse measurements of hydrologic processes with GPR show significant potential to provide non-invasive high-resolution images of pat-terns of water flow. However, limitations in positioning the GPR antennae are often a hindrance to the fast collection of GPR da-ta, which substantially increases the time between repeated measurements. To ad-dress these limitations, an automated GPR data-collection system was constructed to monitor dynamic hydrologic processes with high spatiotemporal resolution.

In two experiments, infiltration was monitored using time-lapse GPR measure-ments in two and three dimensions. The data from both experiments provide sub-stantial qualitative insight about the dy-

namics of hydrologic events and a path for-ward for quantitative analysis of time-lapse GPR data. In this work, we illustrate the advantages of collecting high-resolution time-lapse data, the complexities of pat-terns associated with the wetting of the soil, and evidence of non-uniform propaga-tion of a wetting front through the soil col-umn. XRD Analysis of Soil between Out-crops of Amphibolite and Mica Schist McFarland, William, wmcfarl@ g.clemson.edu, and Scott Brame, Depart-ment of Environmental Engineering and Earth Sciences. Clemson University, Clem-son, South Carolina Outcrops of amphibolite and mica schist were identified on a moderately steep slope in the Clemson Experimental Forest. To determine whether soil core analysis could be used to identify the transition between two different rock types in the absence of outcrops, borehole samples were collected in a linear manner up the slope for hand sample evaluation and XRD analysis. Peak analysis of the XRD output and sample collection displayed chemical weathering between the two outcrops along the slope which was identified as a transition zone between the two parent materials. The transition zone was identified after hand sample analysis showed the compositional differences in mineral percentages between boreholes.

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Photocatalysis of Commercial Naphthenic Acids using Fixed-film TiO2 McQueen, A.D.1, amcquee@clemson.edu, R.L. Kiekhaefer2, C.M. Kinley1, J.H. Rodgers Jr.1; and J.W. Castle2 1Forestry and Environmental Sciences, Clemson University, Clemson, SC 2Environmental Engineering and Earth Sci-ences, Clemson University, Clemson, SC Mining and extraction of bitumen in North-ern Alberta have resulted in unprecedented volumes of oil sands process affected water (OSPW). Naphthenic acids (NAs) are a complex group of organic acids solubilized in OSPW during extraction of bitumen and limit reuse or discharge of process waters due to potential ecological risks to aquatic biota. Photocatalytic degradation is an in-novative treatment approach for NAs. In an effort to alter exposures of NAs and miti-gate potential risks, the overall objective of this study was to measure photocatalytic degradation of commercially available NAs using bench-scale fixed-film TiO2 treat-ments. The specific objectives of this study were to: 1) measure the rate and extent of removal of commercially available NAs when exposed to natural sunlight irradia-tion in the presence of fixed-film TiO2, and 2) measure changes in toxicity in terms of mortality with sentinel fish (Pimephales promelas Rafinesque) and a macroinverte-brate species (Daphnia magna Straus) in 96-h static tests.

Bench-scale chambers were de-signed to target photocatalytic degradation of NA using irradiation of natural sunlight and a thin-film layer of TiO2. In this study, high performance liquid chromatography was used to quantify NAs. Naphthenic acid concentrations decreased >93% after an 8-

h exposure to natural sunlight using fixed-film TiO2 with an average removal rate co-efficient of 0.637 hour-1. There was no measurable toxicity for fish or macroin-vertabrates after >6–h treatments using fixed-film. In sunlight only exposures, NA concentrations decreased 51% following an 8-h exposure, with an average removal rate coefficient of 0.088 hour-1. These results indicate that photocatalytic degradation of NAs using a TiO2 fixed-film can be achieved in relatively short timeframe (i.e. half-lives <2 hours) while concomitantly decreasing toxicity to sentinel aquatic spe-cies. White-rot Fungal Degradation of Naphthenic Acids Muller, S.L.1, slmulle@clemson.edu, A.D. McQueen2, J.W. Castle1, J.H. Rodgers Jr.2

1Environmental Engineering and Earth Sci-ences, Clemson University Clemson, SC 2Forestry and Environmental Sciences, Clemson University Clemson, SC Naphthenic acids are a complex group of carboxylic acids occurring naturally in crude oil deposits that are resistant to bio-degradation. This is of concern to oil com-panies operating in oil sands deposits, as naphthenic acids are present in the process water held on site, resulting in acute toxici-ty to aquatic organisms. Mycoremediation using white-rot fungi is a promising bio-degradation mechanism for naphthenic ac-ids. White-rot fungi use nonspecific extra-cellular enzymes to consume lignin. These enzymes are experimentally proven to de-grade other recalcitrant organic com-pounds, such as PCBs, PAHs, and pesti-cides.

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The objective of this study is to de-termine if mycoremediation is a viable pathway for naphthenic acid degradation. A bench-scale reciprocating mycoreactor was built to allow contact between water containing naphthenic acids and fungi without drowning the organism, using hardwood chips as the mycelial substrate. Naphthenic acid concentrations in the wa-ter were measured at 12-h intervals for 4 days to calculate the rate and extent of naphthenic acid degradation. Hydrologic Effects and Risks Asso-ciated with Increased Upward Flux of Saline Water Murdoch, Lawrence C.; lmur-doc@clemson.edu, Environmental Engi-neering and Earth Sciences, Clemson Uni-versity, Clemson, SC; Shuangshuang Xie; AMEC Foster Wheeler, San Diego, CA; Ronald W. Falta; Environmental Engineering and Earth Sciences, Clemson University, Clemson, SC; and Catherine Ruprecht; Pacific Northwest National La-boratory, Richland, WA

Saline groundwater occurs at shallow depths in many sedimentary basins, and along the Atlantic and Gulf Coasts, and an upward flux of groundwater in these areas could degrade the quality of freshwater aq-uifers and affect aquatic ecosystems. An increase in the upward flux could occur as a consequence of pressurization during CO2 injection, but other factors may also contribute. Relatively large fluxes of sa-line water could be transported upward along faults or improperly abandoned wells, but diffuse upward flow could also occur in response to basin pressurization.

This process would be slower, but diffuse upward flow could affect larger areas than flow through preferential paths, and this motivated us to evaluate the associated risks. We analyzed idealized 2D and 3D geometries representing the essential de-tails of a shallow, freshwater aquifer under-lain by saline ground water. The develop-ment of a freshwater aquifer was simulated by flushing out saline water, followed by simulations of a pulse-like increase in the upward flux from the basin.

The results showed that increasing the upward flux increased the salt concen-tration and mass loading of salt to streams, and decreased the depth to the transition of fresh/salt groundwater. The magnitude of these effects varied widely, however, from a small, slow process that would be chal-lenging to detect, to a large, rapid response that could be an environmental catastrophe. The magnitude of the increased flux, and the initial depth to the fresh/salt transition in groundwater controlled the severity of the response. We also identified risk cate-gories for salt concentration, mass loading, and freshwater aquifer thickness, and used these categories to characterize the severity of the response. This showed that risks depend on the magnitude of upward flux. They were minor when the upward flux was smaller than a few tenths of the magni-tude of recharge, but they could be signifi-cant when the upward flux was greater than the recharge, according to the 2D analyses. Hydrostratigraphy will also play an im-portant role by localizing the discharge of saline water, according to 3D analyses. The major contribution of this work is that it shows how a large increase in diffuse upward flux from a basin could cause sig-nificant problems, but a small increase in upward flux may occur without significant-ly affecting risks to the shallow freshwater flow system. This heightens the im-

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portance of understanding interactions be-tween shallow and deep hydrologic sys-tems when characterizing CO2 storage pro-jects.

Cost-Effective Site Characteriza-tion and Site Remediation Strate-gies: A Community-Supported Model of What Works Even With a Limited Budget Redmond, Jymalyn, jymalyn.redmond@ gmcnetwork.com, and James Robinson, Goodwyn, Mills and Cawood, Inc., Mont-gomery, AL Past operations at an industrial manufactur-ing facility in downtown Cullman, Ala-bama resulted in the release of chlorinated hydrocarbons into the subsurface. The cur-rent site owners of this 12 acre parcel of property are a municipality with a limited budget requiring that the technologies used throughout the project life-cycle are opti-mized to provide the highest return of in-formation and results on dollars spent. Fa-cility operations where solvents, including PCE, TCE, 1,1,1-TCA, and vinyl chloride, were known or suspected to have been used or stored were investigated using pas-sive soil gas techniques. A high-resolution site characterization approach determined the presence or absence of contamination, defined highest concentrations and deline-ated the lateral extent. This technique pro-vided superior information for planning remedial activity. Both in-situ chemical oxidation treatment and phyto-remediation were utilized to lower soil and groundwater contaminant concentrations.

A minimally intrusive, passive soil gas (PSG) technology was used to define

the nature and extent of chlorinated hydro-carbon contamination across this industrial facility. An initial survey targeted three areas of concern (AOCs) where chlorinated hydrocarbon contamination had been iden-tified in groundwater. A 25 foot PSG sam-pling grid was established in the three AOCs, totaling 148 sample locations col-lected in two phases. Only a minimal num-ber of subsequent soil and groundwater samples were required to confirm the re-sults of the PSG surveys and determine the baseline concentrations.

A strategic plan was developed to remove the obsolete buildings, contain the contamination on-site, and enhance the nat-ural attenuation of the chlorinated hydro-carbons. As an alternative to other more intrusive and costly remediation approach-es, a phytoremediation plan, coupled with targeted in-situ remediation treatments in selected areas defined by the PSG Survey, was developed with support of the local municipality and the state environmental agency. The site was divided into sectors to focus on areas of highest concern first, and phyto-plots were planted as funding became available. As a result of the histor-ic industrial practices at the facility, the clayey, sandy soils were believed to be too sterile to support trees; therefore, an initial plot of 200 trees was planted in an area that was augmented with organic matter to demonstrate the viability of the approach. The tree survival and growth rate was good, and an additional 250 trees and shrubs were planted to further enhance the demonstrated natural attenuation that was occurring as evinced by the annual ground-water monitoring program. In-situ chemi-cal oxidation was utilized to breakdown contaminants in the areas of highest con-tamination. Eventually the phyto plots were expanded and further enhanced the breakdown of constituents of concern in

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areas of low to moderate contamination. This multifaceted approach provided a cost effective cleanup strategy.

The strategy employed at this site was one of using low-cost, highly effective methodologies to both characterize and re-mediate subsurface contamination. This model can be applied to a multitude of sites as a cost-effective strategy. Both the local municipality and the surrounding commu-nity supported the multi-year strategy to clean up the contaminants, improve the physical appearance of the property, and return the property to public use. The site contains new greenways that now connect the town’s Greenway Trails with a trail to two local community schools. Graphical data illustrates the reduction in contamina-tion levels resulting of the remediation ap-proach, as well as demonstrating that the contamination has not migrated off-site. Before and after pictures of the site illus-trate the esthetic and functional improve-ments to the property for the community while the site was effectively undergoing remediation. A discussion on the types of advanced injection treatments that were used, including a blend of traditional, as well as innovative, products details how effective these methods are even in tight clays encountered at the site.

Reductive Dechlorination in Sites with High Sulfate and Low (apparent) DHC (dehalococcoides) Bacteria and Other Paradoxes Rossabi, Joseph, rossabi@redox-tech.com, and Haselow, John, Redox Tech, Cary, NC; and Powers, Greg, Redox Tech, Aiken, SC

The biology and chemistry of reductive dechlorination will briefly be reviewed. We will present site data that show that re-ductive remediation can still be a robust remedial mechanism at sites that have low measured concentrations of DHC bacteria, high concentrations of the competing elec-tron acceptor sulfate, or other measured biological or chemical parameters that are apparently contradictory.

Reductive dechlorination methods, chemical, biological, and combined, have been recognized as some of the most effec-tive techniques for remediating chlorinated solvent contamination. Since the first ob-servation of these remediation pathways in the 1980s, there have been a number of technological advances that have signifi-cantly improved the implementation of these methods. One significant advance has been the identification of the bacterial spe-cies and enzymes responsible for reductive dechlorination. An additional improvement has been the ability to more accurately ana-lyze for the presence of these organisms in the subsurface using microbial biotraps de-veloped by D.C. White’s UT Knoxville lab and tech transfer company, Microbial In-sights. These sensitive sampling and analy-sis tools help determine if a site has a ro-bust bacterial population indicating a high likelihood of microbial degradation of the target contaminants. Unfortunately they are prone to the same subsurface vagaries as

23

any type of point sampling and cannot de-finitively determine that the necessary bac-teria and functional genes are not present in a heterogeneous environment. As a result, we find sites with low or non-detectable bacterial concentrations yet concentrations of biological breakdown products that prove that the bacteria must be in the sub-surface somewhere.

In a similar way, point measured values of other parameters that are not con-sistent with laboratory-derived ranges that support biological viability and functionali-ty are often found at sites that are success-fully remediating. Sulfate is a more fa-vored electron acceptor than cDCE and VC, yet the presence of sulfate in ground-water samples has not precluded degrada-tion to ethene and ethane at many sites. Higher oxidation-reduction potentials than expected or pH out of the narrow tolerable range of DHC have also not prevented full reductive dechlorination at some sites.

The answer to these paradoxes is not that laws of science are being broken, rather that we have not sufficiently con-strained our problem (due to a limited number of samples or sensitivity of our measurements), so that sampling and anal-ysis cannot completely describe our site. As with all investigatory techniques, these sampling tools help improve our evolving conceptual model of a site but must not be given more weight than appropriate.

Improvements to the Curve Number Method Using Varia-ble Initial Abstraction and Antecedent Moisture

Santikari, Vijay P., vsan-tik@g.clemson.edu; and Lawrence C. Murdoch, Environmental Engineering and Earth Sciences, Clemson Universi-ty, Clemson, SC

The curve number (CN) method is a con-ceptual model used to estimate the amount of stormflow from a rainfall event. It has been around for 60 years and is still being used in various watershed models. The popularity of the method stems from its simplicity, intuitive conceptual basis, reli-ance on only one parameter, and a large body of documentation and data. The pre-dictive ability of the model, however, has been less than impressive and has been the topic of much scrutiny over the years. An-other concern is that CN, which is sup-posed to be a watershed property, has an inverse relationship with the event rainfall (P). Several researchers have found that changing the way the initial abstraction (early rainfall that does not become runoff (I)) is calculated, improved the model. Oth-ers saw improvement after incorporating antecedent moisture. But the extent of im-provement, however, was modest.

Our hypothesis was that the inverse relationship between CN and P in the con-ventional model is due to the spatial varia-tion of I over the watershed. In the previ-ous models I is lumped over the watershed and is set equal to λS, where S is the maxi-mum potential storage in the soil, and λ is the initial abstraction ratio. In the conven-tional model λ is set equal to 0.2 whereas in the modified models it varies from zero to

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0.5. Instead, we assumed that the water-shed is composed of various landuse-soil parcels each with its own value of I. Theo-retical analyses were performed using vari-ous distributions (uniform, triangular, bi-modal, and normal) of the probability of occurrence for I. The results showed that the average apparent I for the watershed (Ia) varies as a function of P. They also confirmed that ignoring this variation leads to the observed inverse relationship be-tween CN and P. When Ia was incorporated into the model and applied to the field data from two watersheds near Greenville, SC, it showed significant improvement from the conventional model and slight improve-ment from the other modified models in the literature.

Another hypothesis was that the CN models could be improved by using a new approach for including the effects of ante-cedent moisture. Previous models included it using 5-day antecedent rainfall or infil-tration. In the new approach, antecedent moisture decays on a daily time step while being replenished by infiltration during rainfall events. There is no need to put a limit on the number of days considered as the rainfall in the distant past has lesser im-pact than the rainfall in the recent past. When this approach is incorporated into the CN model, the performance was signifi-cantly better than any of the previous mod-els in the literature. When Ia and antecedent moisture were both included in the model, there was a further improvement in the pre-dictive ability. The improvements require increasing the model parameters from one to as many as four. Therefore a hierarchical scheme of model improvement versus model complexity was also developed.

Remapping of the Northern Por-tion of the Six Mile Quadrangle Sellers, Victoria, vseller@g.clemson.edu, Scott Brame, Department of Environmen-tal Engineering and Earth Sciences, Clem-son University, South Carolina Griffin published the geology of the Six Mile Quadrangle in 1967. He defined horn-blende gneiss, biotite gneiss, and mica schist in the quadrangle with minor quartz-ite and indicated that a metamorphic gradi-ent existed between the biotite gneiss and the hornblende gneiss. Recent mapping ef-forts by Garihan (2005) in the Sunset Quadrangle has yielded insights to the re-gional geology and necessitated improved geologic cohesion between the Sunset Quadrangle and the Six Mile Quadrangle.

In this study, we have focused on defining the nature of the Seneca Fault be-tween the underlying Walhalla nappe and the overlying Six Mile Thrust Sheet. The ability to recognize the transitions between the Table Rock gneiss and Poor Mountain amphibolite of the kyanite-grade Walhalla nappe and Tallulah Falls gneiss and schist formations of the sillimanite-grade Six Mile Thrust Sheet are critical skills in this endeavor.

The study area is the northern mar-gin of the Six Mile Quadrangle bordering the southern boundary of the Sunset Quad-rangle. The northern part of the Six Mile Quadrangle is dominated in the west by Table Rock gneiss with interspersed Poor Mountain. Table Rock gneiss is a fine-grained, primarily leucocratic gneiss with minor biotite and hornblende. The Poor Mountain amphibolite is comprised of hornblende, quartz, and alkali feldspar. Hanging wall formations are evident in the central portion of the map due to synclinal folding, with klippen surrounded by foot-

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wall formations in the east. The Tallulah Falls gneiss is composed of biotite and muscovite with porphyroclastic feldspar and quartz. The Tallulah Falls schist ranges from garnet-sillimanite-muscovite-schist to mica-amphibole-schist. Quartz filled veins and pegmatites occur in both the hanging wall and footwall in the northern portion of the Six Mile Quadrangle.

How to Get the Most Out of Ag-gressive Fluid Vapor Recovery (AFVR) Shinall, Brian, bshinall@fruits-us.com, Fruits & Associates, Inc., Acworth, GA Aggressive Fluid Vapor Recovery (AFVR) has been an effective remediation technolo-gy since the mid-1990s, and over time has proven to be an effective means of free-phase NAPL removal. However, since that time, AFVR has evolved into much more than vacuum trucks slurping free product from monitoring wells. Today, there are AFVR units available in the marketplace that can provide data collection and pilot testing information for a wide range of vol-atile organic compounds (VOCs) and semi-volatile organic compound (SVOCs) con-taminated sites, while also providing a via-ble means of cost effective remediation.

So how do we get the most out of AFVR? It starts by first understanding the capabilities of the equipment and selecting the right equipment for the site, and then developing a scope of work that best meets the goals for the site and the AFVR event. This is where communication between the consultant and the AFVR contractor is im-portant, and understanding the relation-ships involved with the various equipment

components and their effect on the subsur-face. Understanding the site history and how to adjust the AFVR equipment over the course of an event becomes key in pro-ducing a successful AFVR event.

In addition to fine tuning an AFVR event, additional remediation processes can be combined with a traditional AFVR pro-cess to provide even more remediation val-ue. Specifically, AFVR can now be readily utilized in combination with air sparging events and in-situ surfactant and chemical oxidation injections. With the increased popularity of AFVR processes, and the ad-vancements made among compatible in-situ remediation techniques, consultants and clients are seeing the added value in evaluating and implementing in-situ reme-diation alternatives at project sites. Key components to successful combination AFVR processes include direct physical contact with the target contaminant zone, available infrastructure, and proper equip-ment specifications. To that end, combin-ing AFVR with in-situ remediation tech-niques is providing a new generation of alternative site clean-up techniques that are very cost effective.

Results from a case study will be presented that demonstrate how AFVR combined with episodic air sparge events reduced dissolved phase BTEX concentra-tions by an order of magnitude, thus elimi-nating the need to install a fixed base reme-diation system.

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In Situ Remediation Of Chlorinated Solvents Using Jet Fracturing Technology – Full Scale Demonstration Slack, William W. wslack@frx-inc.com, and D.E. Knight, FRx, Inc., Taylors, SC; C.R. Ross, D. Chlebica, and N.D. Durant, Geosyntec Consultants, Inc., Acton, MA; T.H. Jorgensen and E.B. Weeth, COWI A/S, Odense, Denmark; and M. Terkelsen and P. Johansen, Capital Region of Denmark, Hillerod, Denmark. In situ remediation of chlorinated solvents in low permeability systems is challenging because of the poor contact between contaminant and treatment reagent that results from constraints upon reagent delivery rates and solvent diffusion into the soil matrix. Pneumatic and hydraulic fracturing can enhance delivery of treatment agents; however, their radius of injection (ROI) is limited in clayey till, and reagent distribution remains controlled primarily by heterogenities such as natural fracture networks.

A full-scale demonstration project using a novel jet fracturing method to deliver zero valent iron (ZVI) powder into glacial till was conducted at a contaminated industrial site. Unlike traditional injection methods, this patent-pending technique reliably nucleates desired sub-horizontal fractures of sufficient extent by exploiting the kinetic energy of high pressure (69 MPa) water jets deployed on direct push rods simultaneously with slurry delivery capabilities.

Prior to implementing jet fracturing, an extensive characterization campaign was performed to delineate the contamination accurately and to establish a baseline against which the performance of

the remedial treatments can be accessed. The jet fracturing and the

subsequent investigation of the ZVI distribution in the clay was performed from November to December 2014. Approximately 50 tonnes of ZVI powder was delivered at depths between 4.5 and 12 m over an area of 750 m2. The ZVI was mixed with sand of similar grain size to provide cost-effective and broad in situ distribution as well as to promote hydraulic conductivity within the fractures. Red, green, or white sand was used in selected fractures to facilitate subsequent identification. Rhodamine dye was injected during another subset of fractures for the same purpose.

The vertical and horizontal distribution of ZVI in the treatment area was mapped in detail with approximately 80 intact soil borings intended to investigate and document the ROI at each injection depth interval. Cores were screened visually and logged in the field for geology, the presence of ZVI, PID readings, colored sand, and/or dye tracer. These data allowed creation of detailed 3-dimensional graphics to document ZVI distribution and fracture form.

Forensic Investigation of a Flooded Limestone Aggregate Quarry to Assess Karst Features Hydrau-lically Connecting the Pit and a Nearby Stream Thompson, Nils, nils.thompson@erm.com, and Adria Reimer, Environmental Resources Man-agement, Inc., Atlanta, Georgia The goal of the investigation was to quanti-fy the contribution of surface water vs.

27

groundwater infilling of the quarry pit and to characterize karst features in the vicinity of a proposed stream channel relocation route. The assessment was critical for the preparation of an action plan for attempts to seal the karst feature and to dewater the quarry pit, which would allow mining to continue.

The following hydrogeologic as-sessment activities were completed to eval-uate the contribution of groundwater to the quarry pit: 1) desktop study of available geologic and hydrogeologic literature, maps, and logs; 2) geologic and hydrogeo-logic characterization of the quarry; 3) electrical resistivity geophysical surveys and confirmatory drilling; 4) land survey of sinkhole features, and monitoring of stream and flooded pit water levels; 5) conceptual hydrogeologic modeling; and 6) assess the vulnerability of the stream and aquifer to proposed dewatering and mining

The hydrostratigraphic model iden-tified a set of former clay-filled joints in the bedrock along a line of sinkholes that connected the stream to a single point in the quarry pit highwall. The collapse of one of the sinkholes allowed surface water from the stream to flush the clay blockage from the joints, leaving a conduit open di-rectly to the pit. Using geophysical and confirmatory drilling data, the location of the joints was positively identified, as well as a larger water-bearing, solutionally-widened joint in the proposed location of the stream relocation. A detailed water-budget analysis established that surface water from the stream flowed into the pit via the widened joint system and that there was little to no groundwater contribution during the flooding event. Calculations of pit-filling rates based on observations and measurements further substantiated that there had been no adverse impacts on the limestone aquifer.

Field-Trial Results for an Experi-mental Dual-Membrane Diffusion Sampler for Metals and Ions in Groundwater Varhol, Brad, brad@eonpro.com, EON Products, Inc., Snellville, Georgia Passive diffusion bag samplers (PDBs) for sampling VOCs in groundwater have be-come a standard practice in the 18 years since Don Vroblesky of the USGS in Co-lumbia SC introduced the technique in 1997 and companies like BLE in Green-ville, SC assisted with the development and testing of a commercial diffusion sampler from 1997 to 1999. Their widespread use has confirmed the cost saving benefits and technical suitability for a wide range of field environments. The principal draw-back to the technique is that it is limited to specific analytes (typically VOCs) which can diffuse through a polyethylene mem-brane.

In early 2014 the EPA Region 6 desired a more efficient, lower cost method for groundwater sampling at sites where various remediation treatment techniques have been employed. Some wells at these sites contained remediation amendment and/or exhibited high turbidity. The wells ranged from 2 to 6-inch diameter with sam-pling depths averaging about 115 to 180 feet below ground surface. All had previ-ously been sampled by conventional sam-pling techniques for a set of metals and ions with total chromium and chromium VI being of special interest.

At the request of the EPA, EON produced experimental sets of dual-membrane diffusion samplers which were installed in May 2014. Samplers were de-ployed for a minimum of 21 days before retrieval. Low flow or HydraSleeve sam-ples were taken for comparison immediate-

28

ly after recovery of the diffusion samplers. The process was repeated in July and Sep-tember 2014. Seventy wells representing 87 well and depth combinations were sam-pled using 174 dual membrane samplers. The sampler configurations varied by length and several different membrane combinations were used. The 2-inch diam-eter wells had one or more samplers in-stalled in series at discrete depths. Some installations in larger wells utilized two or more samplers side by side to produce more sample volume from the same zone or for preparation of sample duplicates.

At the conclusion of the field trial 2,515 comparative samples by analyte for the diffusion sampler verses vs low flow were obtained. Additionally 474 compara-tive samples by analyte for the diffusion sampler verses HydraSleeve were also ob-tained. The data were analyzed for Rela-tive Percent Differences (RPD) in results between sampling method for the same an-alyte at the same well for the same sample event. Compared samples having RPD within 20% were considered good correla-tions. Over 90% of the diffusion samples were within 20% RPD for both low flow and HydraSleeve samples.

The compiled test data from three rounds of sampling indicate a close correla-tion between the dual-membrane diffusion sampler and other sampling techniques for chromium VI, arsenic, zinc, and for various other metals. Results for ions showed close correlations for nitrate, sulfate, and sulfide. Sodium and pH showed almost complete agreement between the methods. In cases where RPD were greater than 20%, the data did not indicate that any spe-cific sampling technique provided more consistent results for any specific analyte evaluated. Several data points that were outliers appeared to be from turbid wells and seemed to favor the dual-membrane

sampler for accuracy due to sample turbidi-ty-induced variance inherent in the other sampling techniques.

The results of this field trial appear to support the use and future study of dual-membrane passive diffusion samplers as an efficient, low cost method of sampling for metals and ionic compounds in groundwa-ter.

Re-examining the Geologic Inter-pretations Used to Delineate the Seneca Fault Villanueva, Rafael, rvillan@clemson.edu, and Scott Brame, Department of Environ-mental Engineering and Earth Sciences, Clemson University, Clemson, South Caro-lina. A large part of the Clemson Forest was mapped in 1973 by Dr. Villard Griffin Jr., a faculty member of the Clemson Universi-ty Geology department. His efforts provid-ed a foundation for an understanding of the rocks and tectonic features including the Seneca Fault in the Clemson Experimental Forest. The goal of this study was to re-examine the geologic interpretations used to delineate the Seneca Fault which is widely recognized as a major structural transition in the Inner Piedmont rocks of the upstate in South Carolina. The area of investigation was confined to the Clemson Forest west of Lawrence Bridge Road and includes the southeast corner of the Old Pickens Quad and the northeast corner of the Seneca Quad.

East-west traverses along streams were conducted to collect samples, identify lithologies, and construct a GIS based map of the area. The focus of this research was

29

to identify the transition from the hanging wall (Tallulah Falls Formation) to the foot-wall (Table Rock gneiss and hornblende gneiss). In this area, the predominant rock encountered immediately on the west side of the fault is the hornblende gneiss. De-tailed mapping has allowed the location of the Seneca Fault to be more precisely known. These results will eventually be used to update the Old Pickens and Seneca geologic quadrangle maps

Changes in Soil CO2 Flux from an Urban Environment due to An-thropogenic Compaction Walters, Dana, danaw@clemson.edu, and Scott Brame, Department of Environmen-tal Engineering and Earth Sciences, Clem-son University, Clemson, SC Compaction or bulk density of soil affects the release of carbon dioxide from soil. Carbon dioxide is produced as a byproduct of below-ground respiration from organ-isms such as plant roots, fungi, soil ani-mals, bacteria and decomposers. Soil respi-ration and decomposition account for near-ly 29% of all naturally produced atmos-pheric carbon dioxide. Worldwide this equates to roughly 220 billion tons of car-bon emissions. In order to determine the correlation between anthropogenic soil compaction and soil CO2 flux, measure-ments were taken on Bowman Field, an area of Clemson University’s campus known to host multiple large-scale social events each year. The soil CO2 flux dropped significantly after the conclusion of Homecoming 2014 and showed a slow recovery in the following ten weeks. The average soil CO2 flux from the field before the Homecoming event was 13.89 µM/m2/

second. After the event, this average flux dropped to 2.15 µM/m2/second. These re-sults demonstrate a negative relationship between anthropogenic soil compaction and natural CO2 flux.

2015 Exhibitors

Joel Daniel Schnabel Engineering

11A Oak Branch Drive Greensboro, NC 27407 (336) 274-9456 jdaniel@schnabel-eng.com

John Sohl Columbia Technologies 1450 South Rolling Rd, Baltimore, MD 21227 (410) 777-8814 jsohl@columbiatechnologies.com

Jim Fydl Mid Atlantic Enviro. Equipment 15 Carroll Drive Bluffton, SC 29910 (877) 623-2462 jfrydl@mae2.com

Ken Cramer Cascade Drilling 1585 Columbia Hwy N, Aiken, SC 29801 (803) 220-3735 (c) (425) 273-7971 kcramer@cascadedrilling.com

Dearal Rodgers Elite Techniques, Inc. 1817 Bishopville Hwy Camden, SC 29020 (803) 425-7324 (c) (803) 223-1117 drodgers.elitetechniques@gmail.com

Sherry Scott Tersus Environmental 1116 Colonial Club Road Wake Forest, NC 27587 (919) 453-5577 Ext. 3 sherri.scott@tersusenv.com

Brian Strickland Geo Lab PO Box 1169 Dacula, GA 30019 (770) 868-5407 brian_strickland@geolab.org

2015 Exhibitors

Peter Byer SAEDACCO Inc. 9088 Northfield Drive Fort Mill, SC 29707 (803) 548-2180 pbyer@saedacco.com

Kenneth Lipscomb AMS Inc. 3803 Grahams Port Lane Snellville, Georgia 30039 (706) 680-9015 kenl@ams-samplers.com

Jorgen Bergstrom GEL Geophysics, LLC P.O. Box 30712 Charleston, SC 29417 (843) 769-7379 jorgen.bergstrom@gel.com

Michael Free Terra Systems, Inc. 130 Hickman Rd, Suite 1 Claymont, Delaware 19703-3579 (484) 889-2214 mfree@terrasystems.net

Alan King GARCO, Inc. PO Box 1907 Asheboro, NC 27204 (336) 683-0911 (c)(919) 451-3960 alk@egarco.com www.egarco.com

Harry O'Neill Beacon Environmental Services, Inc. 2203A Commerce Road, Suite 1 Forest Hill, MD 21050 410-838-8780 harry.oneill@beacon-usa.com

Brian Shinall Fruits & Associates, Inc. 500 North Point Parkway Acworth, Georgia 30102 (770) 974-6999 bshinall@fruits-us.com www.fruits-us.com

2015 Exhibitors

Brian Chew Enviro - Equipment, Inc. 11180 Downs Rd., Pineville, NC 28134 (704) 588-7970 bri-anchew@enviroequipment.com

Jim Fineis Atlas Geo-Sampling 120 Olde Marietta Court, Marietta GA 30060 770-883-3372 jimfineis@atlas-geo.com

Brian Jeffers / Paul Federline Pine 4037 Darling Court, Suite D Lilburn, GA 30047 (800) 842-1088 bjeffers@pine-environmental.com pfederline@pine-environmental.com

Michael L. Kilpatrick II Shealy Environmental Services, Inc. 106 Vantage Point Dr., West Columbia, SC 29172 (803) 791-9700 mkilpatrick@shealylab.com

H.W. Harter III Encotech/Carbon Service & Equipment PO Box 7337, West Columbia, SC 29171 (803) 447-0888 hwharter@carbonservice.net

Tara Esbeck Analytical Environmental Services 3080 Presidential Drive, Atlanta, GA 30340 (770) 457-8177 tesbeck@aesatlanta.com

Patrick Hicks PeroxyChem 1735 Market Street, Philadelphia, PA 19103 (919) 280-7962 Patrick.Hicks@peroxychem.com

David Berkowitz Enthalpy Analytical, Inc. 800-1 Capitola Drive Durham, NC 27713 (919) 850-4392 (c)(919) 491-9841 david.berkowitz@enthalpy.com

2015 Exhibitors

Scott Pearce A & D Environmental Services PO Box 484, High Point, NC 27261 (800) 434-7750 (c)(336) 803-1783 spearce@adenviro.com www.adenviro.com

Allison Queen Pace Analytical 9800 Kincey Ave., Suite 100 Huntersville, NC 28078 (864) 508-4809 allison.queen@pacelabs.com

Alan Hewett Rogers & Callcott Environmental P.O. Box 5655, Greenville, SC 29606 (864) 232-1556 www.rogersandcallcott.com alan.hewett@rogersandcallcott.com

John Horner Landprobe 6004 Ponders Court, Greenville, SC 29615 (864) 527-9324 horner@landprobe.com www.landprobe.com

Doug Knight FRx, Inc. 400 Artillery Rd., Greenville, SC 29687 (864) 356-8424 doug@frx-inc.com

Todd Romero KB Labs, Inc. 6821 SW Archer Rd., Gainesville, FL 32608 (352) 538-4939 toddr@kbmobilelabs.com www.kbmobilelabs.com

Bill Brecher EON Products 3230 Industrial Way S.W., Suite B, Snellville, GA 30039 www.eonpro.com (800) 474-2490 bill@eonpro.com

Adam Phillips / Ethan House Prism Laboratories 449 Springbook Road, Charlotte, NC 28217 (919) 451-3370 / (704) 301-8248 aphillips@prismlabs.com /ehouse@prismlabs.com

2015 Sponsors

Martin Johnson AEDrillingServices,LLC

TwoUnitedWayGreenville,SC29607(864)288‐1986

mjohnson@aedrilling.com

Joe McMurray, President BlueRidgeEnvironmentalServices

2315KingsRd.Ext.Shelby,NC28152(704)482‐2111

Joem@blueridge‐esi.com

George Y. Maalouf Rogers & Callcott Engineers

PO Box 5655 Greenville SC 29606

(864) 232-1556 george.maalouf@rogersandcallcott.com

Scott Pearce A & D Environmental Services

PO Box 484 High Point, NC 27261

(336) 803-1783 spearce@adenviro.com www.adenviro.com

John Haselow / Joe Rossabi Redox Tech

200 Quade Drive Cary, NC 27513-7402

(919) 678-0140 jhaselow@redox-tech.com

Robert Workman CRB Geological & Environmental

(864) 283-2000 rworkman@crbgeo.net

www.crbgeo.com

Tad Goetcheus / Shaun Malin HRP Associates, Inc.

1327 Miller Road, Suite D Greenville, SC 29607

864-561-5007 shaun.malin@hrpassociates.com

Drew Baird Regenesis

123 Ridgecreset Drive Greenville, SC 29609

(864) 240-9181 dbaird@regenesis.com

Allison Queen Pace Analytical

9800 Kincey Ave., Suite 100 Huntersville, NC 28078

(864) 508-4809 allison.queen@pacelabs.com

Cecil HueyEmeritusProfessorClemsonUniversity

106BFluorDanielBuildingClemson,SC29634