Revised treatability workplan - in situ reactive zone ... · Workplan - In Situ Reactive Zone™ Technology - Phoenix-Goodyear Airport - North Superfund Site, Goodyear, Arizona Prepared

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2041429

Crane Co.

Revised Treatability Workplan- In Situ Reactive Zone™Technology - Phoenix-Goodyear Airport NorthSuperfund Site,Goodyear, Arizona

14 May 2004

ARCADISInfrastructure, buildings, environment, communications

ARCADIS

Michael A. Hansen,Principal Engineer

David S. LilesSenior Scientist

Robert A. Mongrain RGEnvironmental Business Practice Manager

Revised TreatabilityWorkplan - In SituReactive Zone™Technology -Phoenix-GoodyearAirport - NorthSuperfund Site,Goodyear, Arizona

Prepared for:

Crane Co.

Prepared by:

ARCADIS G&M, Inc.

8222 South 48th Street

Suite 140Phoenix

Arizona 85044

Tel 602 438 0883

Fax 602 438 0102

Our Ref.:

AZ00987.0002

Date:

14 May 2004

77i/s document is intended only for the use

of the individual or entity for which it was

prepared and may contain information that

is privileged, confidential, and exempt from

disclosure under applicable law, Any

dissemination, distribution, or copying of

this document is strictly prohibited.

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ARCADIS

Acronyms and Symbols

1. Introduction

1.1 Background

1 .2 Objectives

1 .3 Soil Sample Collection

1 .4 Groundwater Sample Collection

2. Microbiologically Enhanced Reductive Dechlorination of TCEand Perchlorate Reduction

2.1 Microcosm Preparation

2.2 Incubation

2.3 Microcosm Headspace Analysis

2.4 Sacrificial Sampling Procedure for Aqueous Analysis

2.4.1 cVOC Analysis

2.4.2 H2S, Perchlorate, Sulfate, Dissolved Iron and Manganese, andNitrate Analysis

2.4.3 Permanent Gas and Light Hydrocarbon Analysis

2.5 Bioaugmentation

3. Nano-scale ZVI Treatment of TCE and Perchlorate

3.1 Nano-scale ZVI Setting

3.2 Nano-scale ZVI Column Test Methodology

3.2.1 Procedure for Mixing Nano-scale ZVI and Site Soil

3.2.2 Establishment of Soil Columns

3.2.3 Soil Column Operation

4. Joint Nano-scale ZVI and Microbiologically Enhanced ReductiveDechlorination Treatability Study

4.1 Justification for Joint Investigation

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Table of Contents

ARCADIS Table of Contents

5.

6.

4.2 Joint Microbiology and Nano-scale ZVI Batch Test Methodology

4.2.1 Establishment of Microbiological Soil Column

4.2.2 Microbiological Column Operation

4.2.3 Establishment of Nano-scale ZVI Soil Column

4.2.4 Joint Microbiological Column, Nano-scale ZVI ColumnOperation

Schedule and Reporting Summary

References

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List of Tables

Table 1-1. Data Parameters to be Analyzed during Microcosm Study SampleCollection Attachment

Table 2-1. Serum Bottle Microcosm Identities 11

Table 2-2. Summary of Analyses to be Performed by Microcosm Bottle Set 12

List of Figures

Figure 1-1. Site Plan Showing Proposed Location of IRZ Treatability Study SampleSite Attachment

Figure 3-1. Diagram of Nano-scale ZVI Column Test Apparatus 18

Figure 4-1. Joint Apparatus for Microbiological and Nano-scale ZVI Column Study 23

ROBERTAMONGRAI

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ARCADIS List of Acronyms

Acronyms and Symbols

°cCH»

cis 1,2-DCE

CO2

COC

cVOCs

DNAPL

DO

ESTCP

g

GC-ECD

g/L

HC1

HNO3

H2S04

H2S

IRZ™

ITRC

mg/L

ug/L)

uM/L

H

mL

N2

02

degrees Celsius

methane

cis 1, 2-dichloroethene

carbon dioxide

constituent of concern

chlorinated volatile organic compounds

dense, nonaqueous phase liquid

Dissolved Oxygen

Environmental Security Technology Certification Program

grams

gas chromatograph with an electron capture detector

grams/liter

hydrochloric acid

nitric acid

sulfuric acid

hydrogen sulfide

In Situ Reactive Zone™

Interstate Technology Regulatory Council

milligrams/liter

micrograms/liter

micromoles/liter

micron

milliliter

nitrogen

oxygen

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ARCADIS List of Acronyms

OD

ORP

TCE

ZVI

eq/L

ERD

USEPA

RABITT

PH

TOC

VC

VGA

w/v

outside diameter

oxidation/reduction potential

trichloroethylene

Zero Valent Iron

equivalents/liter alkalinity

enhanced reductive dechlorination

United States Environmental Protection Agency, Region DC

Treatability Test for Evaluating theReductive Anaerobic Biological Into Remediate Chloroethenes

Potential Applicability of theSitu Treatment Technology

hydrogen ion concentration

total organic carbon

vinyl chloride

volatile organic analyte

weightvolume percentages

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ARCADIS Revised TreatabilityWorkplan - In SituReactive Zone™Technology

1. Introduction

1.1 Background

ARCADIS G&M Inc. (ARCADIS) has prepared this Treatability Study Workplan(Treatability Workplan) on behalf of Crane Co. to implement an In Situ Reactive Zone(IRZ) treatability study for groundwater at the Phoenix-Goodyear Airport - NorthSuperfund Site (PGA-North [the Site]). The treatability study evaluates thecombination of enhanced microbial degradation via corn syrup addition and chemicalreduction using zero-valent iron (ZVI) for remediation of trichloroethene (TCE) andperchlorate contaminants.

The degradation of chlorinated ethenes such as TCE via reductive dechlorination iswell documented. The reductive dechlorination of chlorinated ethenes proceeds via thefollowing pathway:

Tetrachloroethene (PCE) -» TCE -> cis-l,2-Dichloroethene (DCE) -> Vinyl Chloride(VC) -> Ethene

In order for this dechlorination pathway to reach completion (formation of ethene), thegeochemical environment must be in the range of sulfate reducing to methanogenic(Bradley, 2003). In aquifers that are not naturally in this range, the appropriate redoxconditions can be achieved through the addition of an electron donor/carbon source tothe treatment area. Commonly used electron donors include molasses, lactate, HRC™,alcohols, and several others. Delivery of sufficient electron donor stimulatesindigenous microbial activity and causes a succession of terminal electron acceptorreactions (oxygen reduction, nitrate-reduction, iron and manganese reduction, sulfatereduction and methanogenesis). Once the system is in the range of sulfatereducing/methanogenic conditions, dechlorination of chloroethenes operates as asignificant process.

Dechlorination of chloroethenes can occur either via microbial degradation (carbonaddition), or via chemical reduction in the presence of a chemical reductant, such aszero valent iron (ZVI). Stimulation of microbially mediated dechlorination is achievedthrough the periodic injection of a carbon/electron donor solution. Similarly,stimulation of chemical reduction via ZVI requires the delivery of ZVI to the treatmentarea. In both cases, the loading of carbon solution/ZVI must be sufficient to reduceany influx of competing electron acceptors (such as sulfate) into the treatment area andalso to meet the demand posed by the contaminants themselves.

While not as much research has been focused on the degradation of perchlorate, severalstudies have demonstrated that biologically mediated perchlorate reduction can occur

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in groundwater systems (Xu et al., 2003 and references within). The reduction ofperchlorate proceeds via the following pathway:

C1O4- -» C1O3- -> C1O2~ -» Cl" and O2

Research conducted to date suggests that the reduction of perchlorate can occur underconditions in the range of nitrate reduction, and there is evidence that perchloratereduction can even occur in the presence of some oxygen (Xu et al., 2003 andreferences within). Similar to TCE degradation, stimulation of perchlorate reductionhas been achieved through the addition of carbon substrates, most commonly acetate.The electron donor demand to achieve the desired perchlorate reduction will depend onthe levels of alternate electron acceptors (oxygen and nitrate) in the system. Previousstudies on the impact of sulfate on perchlorate reduction suggest that the presence ofsulfate does not negatively impact the rate of perchlorate degradation.

Based on studies conducted to date, degradation of TCE and perchlorate both readilyoccur via biologically-mediated reduction reactions in the presence of adequatecarbon/electron donor. One of the main challenges to achieving sufficient degradationof TCE in situ is delivery of enough carbon substrate to address competing electronacceptor demand and achieve the strongly reducing conditions required for efficientTCE dechlorination to ethene. This will be particularly true at the subject Site, whichhas relatively high sulfate concentrations. However, it appears the degradation ofperchlorate does not require these strongly reducing conditions, and can undergoreduction in the presence of sulfate. This is a positive indicator for the success ofperchlorate reduction via carbon/electron donor addition.

Reduction of TCE using ZVI is also well established. In addition, the reduction ofperchlorate using ZVI has been documented (Moore et al, 2003). Reduction ofperchlorate using ZVI will depend on several of the same factors that influence TCEreduction. Specifically, the presence of elevated sulfate in situ could represent asignificant demand for ZVI. Therefore, the use of a combined carbon/electron donorinjection and ZVI approach may be very well suited to the conditions at the subjectsite.

The following section describes the specific objectives for the evaluation of theenhanced microbial degradation (via corn syrup addition) and ZVI technologies forremediation of TCE and perchlorate contamination.



1.2 Objectives

The objectives of the treatability study described in this Treatability Workplan are asfollows:

1) Verify that subsurface introduction of an organic carbon substrate (corn syrup)will result in the development of an indigenous microbiological communitycapable of both reductive dechlorination of TCE and reduction of perchloratepresent in groundwater at the Site. Should the indigenous microbiology fail tosupport treatment of the TCE and/or perchlorate bioaugmentation will beexperimentally investigated at the bench-scale level.

2) Evaluate the use of nano-scale zero valent iron (ZVI) as a means treat TCE andperchlorate present in groundwater at the site.

3) Evaluate the potential synergies associated with the joint use of both enhancedmicrobiological reductive dechlorination and nano-scale ZVI to treat TCE andperchlorate present in site groundwater.

4) Provide supporting data and justification for execution of field-scale testing ofthe two IRZ™ technologies outlined above at the site during 2004.

This Treatability Workplan details a treatability study intended to technically confirmthe applicability of the two IRZ™ technologies to address dissolved phase chlorinatedvolatile organic compounds (cVOCs), primarily TCE, as well as perchlorate ingroundwater at the site. This treatability study is designed to meet the requirements ofthe regulatory bodies overseeing site remediation efforts as referenced in previouslyreceived comments to a proposed enhanced reductive dechlorination (ERD) field pilotstudy contained in a comment letter from the United States Environmental ProtectionAgency Region 9 (EPA) that was addressed to Dr. Anthony Pantaleoni of Crane Co.and dated August 21, 2003.

The laboratory study described in this Treatability Workplan is part of a phasedevaluation of this technology for remediation of cVOCs and perchlorate ingroundwater at the site. Following the lab study described here, a pilot test will beimplemented at the Site, as described in the Workplan forln-Situ Reactive Zone PilotTest - Phoenix-Goodyear Airport North Superfund Site, Goodyear, Arizona (IRZWorkplan). Modifications to the pilot test design may be made based on the results of



the lab study. Following the pilot test activities, a decision regarding full-scaleimplementation of the technology at the PGA-North site will be made.

In order to meet the goals outlined above, batch treatability tests of the individual IRZtechnologies outlined above will be performed. The individual batch tests proceduresare described in Sections 2 and 3 of this Treatability Workplan. Section 4 of theTreatability Workplan describes the procedures for a column study design to evaluatethe combination of the two technologies. The balance of Section 1 describes theproposed procedure that will be used to collect Site media for use in the treatabilitytesting.

Where possible, methodologies for the laboratory studies included in this TreatabilityWorkplan have been drawn from EPA or Interstate Technology Regulatory Council(ITRC) guidance. In addition, the Treatability Test for Evaluating the PotentialApplicability of the Reductive Anaerobic Biological In Situ Treatment Technology(RABITT) to Remediate Chloroethenes produced under the Environmental SecurityTechnology Certification Program (ESTCP) has been heavily drawn upon.

1.3 Soil Sample Collection

ARCADIS intends that the studies proposed in this Treatability Workplan mimic the insitu microbial ecology as closely as possible. Previous investigation efforts andgroundwater monitoring data have confirmed that the groundwater conditions areaerobic. Therefore, methods and precautions intended to maintain anaerobicconditions during the collection of environmental samples are unwarranted. However,sterile technique will be use to the extent feasible.

Soil samples for the treatability testing will be collected by ARCADIS' Phoenix staffusing a reverse-circulation air drilling rig, or equivalent method. Soil borings will beadvanced to depths below the water table and may extend to approximately 160 feetbelow ground surface (bgs). In order to evaluate potential for treatment of theheterogeneous materials identified at the PGA-North Site, ARCADIS anticipatescollecting samples from various lithologies as part of the laboratory study. Knowledgefrom previous investigations (lithology and analytical data) together with observationsmade during drilling operations will guide the sample selection depths for the study.The proposed location for the Treatability Study sample site is generally centeredbetween, and just south of EPA's Phase II boring locations Cl and C2 as depicted on

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Figure 1-1 (attached). This location was selected because 1) there were no datagenerated during the EPA's Phase II investigation; 2) it is not anticipated to containconcentrations of contaminants indicative of dense, non-aqueous phase liquid(DNAPL); and 3) it is close enough to the drywell area to provide usable results toconnect the bench-scale testing program to the proposed field-scale pilot test.

Once the appropriate depth is reached for collection of soil in support of thistreatability study, samples will be collected using a SimulProbe® or 3.7-inch corebarrel, depending on the degree of soil cementation. If gravel to cobble size materialsare encountered, samples may be recovered using an oversize (5-inch) split-barrelsampler. As gravel and cobble intervals are not the predominant materials identified atthe Site, medium to fine sand or silty sand soils are desirable for the laboratory study.Brass or stainless steel sleeve liners will be used for the sampler and will be disinfectedwith isopropanol prior to being placed into the sample barrel. After the sampler isdriven to the desired depth, it will be retrieved, split open, and the sleeve linersremoved. Immediately after removing the sleeved cores from the collection barrel, thesleeve ends will be covered completely with Teflon™ sheets and capped. The capswill be positioned in such a way that the Teflon™ sheeting is not wrinkled and anairtight seal is provided on the sleeve ends. The caps will then be taped securely to thesleeve to maintain the airtight seal. The sleeve will be labeled with a permanentmarker or paint pen with the sample identification, collection location, depth ofcollection, time and date, and orientation. The capped sleeve will then be placed in ascalable plastic bag and ultimately transported in a cooler at 4 °C and accompanied bya chain-of-custody to the ARCADIS Treatability Laboratory in Durham, NC(Laboratory) via overnight express. At the laboratory, it will be refrigerated untilinitiation of the treatability studies. All of the collection information that was writtenon the sleeve label will be copied to the field notes or logbook along with anyappropriate comments or observations made during the collection and sealing process.

ARCADIS intends that the soil used for microcosm construction be free of anypotential DNAPL. Distribution of DNAPL in soil can be heterogeneous and thisheterogeneity can negatively affect the laboratory soil homogenization process; thesetechniques rarely achieve complete homogenization (based on our experience and theliterature). If soil containing DNAPL were used to establish the microcosm study, itcould potentially skew TCE concentrations in the water phase within individual studytreatments and threaten interpretation of the study results. To guard against collectionof microcosm soil samples containing DNAPL, a portion of each split-barrel samplecollected will be tested in the field for the presence of DNAPL using Sudan IV dyetesting and visual inspection.



Table 1-1 contains the soil data to be collected during the treatability study samplecollection phase. The soil data parameters include Sudan IV Dye testing (fieldscreening), EPA Method 8260 analysis, and alkalinity. Sudan IV dye will reveal thepresence of DNAPL. As noted above, soil containing DNAPL can be difficult tohomogenize and thus lead to inconclusive laboratory results. EPA Method 8260 willquantify the contaminants and their lesser chlorinated daughter products in the soilcollected. These results will be utilized to evaluate whether the collected soiltechnically fulfills requirements for the treatability study and provide means ofassessing the presence of sorbed phase TCE and its daughter products. Soil alkalinityis a measure of the buffering capacity of the soil towards decreases in pH.Implementation of the IRZ technology typically results in a need for additionalbuffering capacity in poorly buffered soils. Measuring the alkalinity of the collectedsoil will permit ARCADIS to assess the need to buffer the microcosms discussed laterin this document.

1.4 Groundwater Sample Collection

A representative groundwater sample will be collected from the same depth intervals asthe soil samples to support this laboratory study. The groundwater samples will becollected using the SimulProbe® depth-specific groundwater sampling technology.Selected parameters (dissolved oxygen, oxidation/reduction potential [ORP], pH,temperature, and conductivity) will be collected using a YSI multi-probe in the field.The groundwater samples will be split in the field for delivery to the analyticallaboratory and the treatability laboratory. Samples to be analyzed for baselineconditions will be transferred into laboratory- prepared glassware suitable for theanalysis to be performed. The samples to be used in the microcosm studies will betransferred into one-gallon sterile amber glass jugs. All samples will be ultimatelytransported in coolers at approximately 4 °C and accompanied by chain-of-custodydocumentation to the Laboratories via overnight express. Once at the TreatabilityLaboratory the sample will be refrigerated until it is used to establish the microcosmstudy.

ARCADIS will attempt to collect a groundwater sample containing between 3 to 5milligrams/liter (mg/L) of TCE [18 to 30 micromoles/liter (uM/L)]. The actual TCEconcentration will be confirmed in accordance with EPA Method 8260 prior to usingthe groundwater for treatability purposes. If the TCE in the groundwater sample is lessthan 3 mg/L, the groundwater will be spiked with TCE. ARCADIS expects to find atleast 30-50 micrograms/liter (ug/L) perchlorate in the groundwater collected to supporttreatability studies. The groundwater perchlorate concentration will be confirmed in



accordance with EPA Method 314. If the perchlorate in the sample is less than 30u,g/L, the groundwater will also be spiked with perchlorate. After sample collection,ARCADIS will also determine the bicarbonate alkalinity in the collected groundwatersample.

The groundwater parameters include dissolved oxygen (DO), oxidation reductionpotential (ORP), pH, conductivity, USEPA Method 8260, and alkalinity. The accuracyof DO and ORP measurements is contingent on the testing being performed in thefield. Further information on equipment calibration and field methods is presented inthe Quality Assurance Project Plan (QAPP), accompanying this document. Thegroundwater parameter information characterizes the baseline aquifer conditions fromwhich the water was removed. DO and ORP are means to genetically assess the typeof microbial community present in a given portion of contaminated aquifer.Conductivity is a test conducted in both the field and a lab setting. Measurements ofconductivity obtained in the field are used to ascertain that a well has been properlypurged prior to sample collection and the results obtained from both the field and thelaboratory can also assist in developing a general sense of the expected type ofbacterial community present. USEPA Method 8260 will provide the concentrations ofTCE and daughter products present in the groundwater sample. Knowledge of thecontaminant level(s) is important to review prior to microcosm study set-up. The TCEconcentration should be at least ten times the detection limit and representative of thesite prior to setting up the microcosm study to provide for adequate analyticalsensitivity to demonstrate biodegradation. As with soil, groundwater alkalinity is animportant parameter used to guide the addition of supplemental buffer during cornsyrup addition to microcosms established in the laboratory.

Table 1-1 (attached) contains the soil and groundwater data to be collected during thetreatability study sample collection phase.

2. Microbiologically Enhanced Reductive Dechlorination of TCE andPerchlorate Reduction

This section describes a batch microcosm test design to evaluate the potential formicrobial enhanced treatment of TCE and perchlorate. Corn syrup was selected forevaluation in this lab study for several reasons. First, ARCADIS has significantexperience with the use of simple sugar substrates (molasses in particular), as opposedto alcohols or other compounds, for stimulation of reductive dechlorination. Molasseshas proven to be an effective substrate in both laboratory and field settings. While notas widely used to date, ARCADIS has also used corn syrup, another simple sugar

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substrate, at several sites. Corn syrup was selected for use at PGA-North as opposed tomolasses because it does not contain residual sulfate as molasses does. Due to therelatively high sulfate concentrations in groundwater at the PGA-North Site, a donorthat did not contain sulfate was desired. The performance of corn syrup in studiesconducted to date by ARCADIS is a positive indicator for the potential effectiveness ofcorn syrup in the present study. Second, corn syrup was selected because it is a food-grade product that contains no constituents that would negatively impact groundwaterquality upon injection (trace metals and etc.). Thirdly, corn syrup poses no health andsafety issues to workers using it in the field, and it is easy to handle and can bemixed/injected using similar protocols and equipment as molasses. Finally, corn syrupwas selected for its cost-effectiveness compared to other electron donors. Corn syrupis the proposed electron donor for this study. The batch testing program, utilizingserum bottles, is intended to determine whether the indigenous microbial community iscapable of degradation of TCE and perchlorate under the conditions present ingroundwater at the Site (i.e., bulk aerobic and high levels of sulfates).

Serum bottle studies have traditionally been utilized at the bench-scale to elucidate theoutcome of efforts to enhance microbiologically induced bioremediation of chlorinatedethenes (and other contaminants) prior to the initiation of field-pilot studies. Examplesof this programmatic approach can be seen for natural attenuation in an article byFindlay and Fogel (Findlay and Fogel, 2000). This article references a EPAmethodology (EPA/600/R-98/128) for conducting serum bottle microcosm tests and anAir Force methodology for conducting serum bottle microcosm tests (NTISADA352416). A third protocol for conducting serum bottle tests entitled 'TreatabilityTest for Evaluating the Potential Applicability of the Reductive Anaerobic BiologicalIn Situ Treatment Technology (RABITT) to Remediate Chloroethenes" and producedunder the Environmental Security Technology Certification Program (ESTCP) isperhaps the most germane to this treatability study since it focuses on carbonamendments to enhance microbiological reductive dechlorination rather thaninvestigating natural attenuation(http://www.estcp.org/documents/techdocs/Rabitt_Protocol.pdf). Where possible,methodologies for this portion of the Site treatability study have been drawn from theRABrrr protocol.

2.1 Microcosm Preparation

Realistic recreation of site-specific conditions requires that both soil and groundwaterrepresentative of the impacted subsurface (see Sections 1.2 and 1.3) be collected and



included in the serum bottle study that is planned to evaluate and confirm the proposedenhanced microbiology remedy.

Because of the aerobic nature of the groundwater plume at the site, microcosms will beprepared on the laboratory bench rather than in a glove box. Each microcosm willconsist of an autoclaved 160-mL serum bottle, with Teflon™ lined, butyl-rubberseptum that has been autoclaved before use to drive off organics that potentially couldinterfere with the analysis and aluminum crimp caps. A mixture of subsurface soil (50grams dry weight [g]) and groundwater from the site (100 mL) will be added to eachmicrocosm initially. The soil utilized will be previously homogenized manually instainless steel bowls with stainless steel implements with consideration to both sterilityand cVOC volatilization. Aseptic technique coupled with isopropyl alcoholdisinfection of homogenization implements will be utilized to maintain sterileconditions during soil homogenization. The homogenization process will begin byremoving soil samples from the refrigerator immediately prior to homogenization. Thehomogenization of soil chilled to approximately 4° centigrade will minimizevolatilization. Potential cVOC volatilization will also be addressed by minimizing theexposure time during homogenization.

Each microcosm will then be amended with a solution of resazurin to a concentrationof 0.8 mg/L. Resazurin is a colorimetric indicator of low redox potential. Whenoxygen in present, the microcosms will appear pink. As individual microcosms goanaerobic, the water phase within them will turn from pink to colorless.

If groundwater analyses indicate bicarbonate alkalinity < 0.05 equivalents/L (eq/L),NaHCO3 buffer will be added to the microcosms to achieve that level in aqueousphase. Buffer will be added to all the groundwater that is to be distributed into themicrocosms.

Following these steps, amendments required to mimic anticipated field-scale treatmentwill be added to differentiate treatments and controls will be established as describedbelow. To satisfy analytical requirements for sample volume, the Laboratory staff willprepare three replicate microcosms per sampling interval. One microcosm will bededicated to the analysis of cVOCs. One microcosm will be dedicated to the analysisof perchlorate, hydrogen sulfide (H2S), sulfate, dissolved iron, dissolved manganese,nitrate, and total organic carbon (TOC). The final microcosm will be dedicated to theanalysis of permanent gases (methane, carbon dioxide, nitrogen, and oxygen) and lighthydrocarbons (ethane and ethene). There will be a total of five sampling intervalsincluding time zero sampling. One duplicate analysis will be conducted on eachtreatment during the study interval.



Abiotic controls (Bottle Set 1) will be established through the addition of mercuricchloride to each individual bottle at a concentration 5 grams/liter (g/L). In addition, thesoil used to establish the abiotic microcosms will be autoclaved in a thin layer for atleast 1.5 hours before establishing this bottle set. These controls serve to provideestimates of abiotic losses (e.g., losses through the septum) of TCE from the bottlesover the incubation interval.

Biological controls (Bottle Set 2) with no amendments (no vitamins, buffers, etc.except possibly TCE or perchlorate, if deficient) will be used to assess the backgroundmicrobial activity that occurs in the absence of amendments (similar to a naturalattenuation situation at field-scale).

Carbon substrate amendment utilizing corn syrup will take place in two separatetreatments at two separate dosage levels in Bottle Set 3 and Bottle Set 4. Bottle Set 3will be a low dose corn syrup treatment and receive 800 mg/L total organic carbon(TOC) as corn syrup at time zero. Bottle Set 4 will be a high dose corn syrup treatmentand receive 2,000 mg/L TOC as corn syrup at time zero.

The TOC concentrations included in this laboratory microcosm work plan are muchhigher than the target TOC concentrations mentioned in the draft IRZ Workplan. The100-300 mg/L TOC concentration referenced in the draft IRZ Workplan is the desiredconcentration of TOC at a monitoring well closer to the fringes of the reactive zonethat is created. TOC concentrations between the extreme monitoring well(s) and theinjection well(s) will be a concentration continuum. In addition, whereas themonitoring well discussed in the draft IRZ Workplan sees a continuous flow of TOCladen groundwater from upgradient, ARCADIS' goal for the individual serum bottlewithin a treatability study is to add carbohydrate at study onset and not again so thatsufficient TOC to achieve the goals of the study needs to be added at the study onset.With the higher concentrations of TOC included in this work plan, ARCADIS does notexpect to have to add more corn syrup during the study. If additional TOC is requiredto support reductive dechlorination, it will be added to individual serum bottles as aconcentrated corn syrup solution at a later point in the study.

Table 2-1 summarizes the serum bottles involved in this treatability study. Afterpreparation, and prior to final sealing, the headspaces of all serum bottles will bepurged for 1 minute with argon gas to eliminate atmospheric oxygen. The Teflon™coated butyl rubber septa will be inserted and crimped in place with aluminum rings.The necks of the microcosms will then be dipped in paraffin to create a secondary seal.After paraffin application, the septum of each microcosm used for headspace

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monitoring will be punctured with a sterile ~22-gauge stainless steel needle with luer-lok hub that is attached to a three-way luer valve. This valve and needle arrangementconnects efficiently to a gas tight syringe thus permitting the injection of additionalargon for serum bottle over pressurization or the removal of headspace gas forsubsequent analysis as discussed below. The insertion of this reusable needle andvalve arrangement also means that each microcosm septum is only punctured oncerather than multiple times this improving the overall integrity of the septa over thecourse of the microcosm study. After purging and sealing the microcosm bottles,ARCADIS will over pressurize each serum bottle with argon gas not to exceed 0.5atmosphere of gauge overpressure.

Table 2-1. Serum Bottle Microcosm Identities

Bottle SetNumber

1

2

3

4

Microcosm Description

Abiotic Control

Unamended Biological Control

Low Dose Corn Syrup

High Dose Corn Syrup

Number of160 ml Serum Bottles

3 Bottles x 5 Events = 1 5




Number ofBottles for Duplicate

3 Bottles x 1 Event = 3




Table 2-2 summarizes the analyses that will be performed on each microcosm bottle setat periodic intervals.

2.2 Incubation

Microcosms will be incubated at ambient laboratory temperatures (20-25 °C) underquiescent conditions and in the dark. Though such temperatures are likely somewhathigher than subsurface field temperatures, higher temperatures should accelerate themicrocosm studies, without altering the relative results of electron-donor comparisons.

When headspace analyses indicate depletion of TCE and the appearance of lesserchlorinated daughter products, a group of three microcosms from each treatment willbe sacrificed to facilitate quantification of the target analytes in the aqueous phase.

2.3 Microcosm Headspace Analysis

ARCADIS intends to utilize microcosm headspace monitoring for chloroethenesincluding 1,2-dichloroethene and vinyl chloride to monitor reductive dechlorination inthe aqueous phase so that aqueous phase analytes can be quantified at meaningful

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intervals during the incubation period. Chloroethenes can be measured in a screeninganalysis using headspace samples (0.1 to 0.5 mL) with a suitably configured gaschromatograph with an electron capture detector (GC-ECD) located in the Laboratory.

Table 2-2. Summary of Analyses to be Performed by Microcosm Bottle Set

Bottle SetNumber

1

2

3

4

Treatment Description

Abiotic Control

Unamended BiologicalControl

Low Dose Corn Syrup

High Dose Corn Syrup

HeadspaceAnalysis

TO, 1,2,3,4

TO, 1,2,3,4

TO, 1,2,3,4

TO, 1,2,3,4

Method8260

TO, 1,2, 3,4

TO, 1,2,3,4

TO, 1,2,3,4

TO, 1,2,3,4

Inorganics

(H2S, CI04,Dissolved Fe &

Mn, Sulfateand Nitrate)

TO, 1,2,3,4

TO, 1,2,3,4

TO, 1,2,3,4

TO, 1,2, 3,4

LightHydrocarbons

(Ethane &Ethene)

TO, 1,2,3,4

TO, 1,2,3,4

TO, 1,2,3,4

TO, 1,2,3,4

PermanentGases

(CH4, COJf N2, 02)

TO, 1,2,3,4

TO, 1,2,3,4

TO, 1,2,3,4

TO, 1,2,3,4

TO = Time Zero Sampling Event

1 = First Sampling Event

2 = Second Sampling Event

3 = Third Sampling Event

4 = Fourth Sampling Event

Using a GC/ECD, ARCADIS will screen headspace gases for TCE, cis 1,2-dichloroethene (DCE), and vinyl chloride (VC). At a minimum, headspace screeningwill be conducted monthly. Prior to each round of headspace analysis, two blanks anda check standard will be analyzed on the screening instrument. Results of the checkstandard analysis should be ± 15% of the true value. ARCADIS estimates detectionlimits for TCE, cis 1,2-DCE, and VC at 100 ppmv. These estimated detection limitswill be confirmed during the preparation of a project specific calibration curve toprecede the analysis of the first headspace sample on this project. The confirmeddetection limits will be included in the report for this microcosm.

g:\envAproj\900\987 crane\work planVevised treatability workplan.doc 12


Headspace sampling will be performed with a locking, gaslight syringe. Carefulaccounting of the total gaseous volume sampled over time will be managed so as toavoid creating a vacuum that would draw air in during headspace sampling events anddisqualify the affected microcosm. If headspace gas sample accounting proceduressuggest there is a danger of creating a vacuum, ARCADIS will add additional argongas to microcosm(s) via gas-tight syringe.

2.4 Sacrificial Sampling Procedure for Aqueous Analysis

After headspace analysis confirms that biologically induced reductive dechlorinationhas begun to occur, series of microcosms will be sacrificially sampled to permitanalysis of aqueous phase analytes.

2.4.1 cVOC Analysis

One microcosm from each bottle set or treatment will be opened and two 40-mL VOAvials supplied by the contract analytical lab and containing the hydrochloric acid (HC1)preservative specified by EPA Method 8260 will be filled with microcosmgroundwater using a 60-mL gas tight syringe and a 14-gauge to 16-gauge stainless steelneedle. The needle will be inserted through the neck of the serum bottle and thesyringe will be used to draw up 45 mL of water. The needle will then be removed andthe water from the syringe will be used to fill the first of two 40-mL VOA vials to azero headspace condition by allowing the water to gently run down the side of theVOA vial. This procedure will be repeated to fill a second VOA vial. The syringe willthen be triple rinsed with deionized water between serum bottles of the next bottle setto prevent cross contamination. During each cVOC sampling interval, ARCADIS willcreate a cVOC rinse/trip blank by filling a triple rinsed syringe with deionized waterfrom the laboratory and dispensing it into two HC1 preserved VOA vials for transportto the independent contract analytical laboratory and subsequent analysis. Thisrinse/trip blank will be used to confirm that the triple rinse procedure for cleaning the60-mL gas tight syringe was adequate and that there were no cVOCs introduced to thewater samples during transit to the independent contract analytical laboratory.

ARCADIS recognizes that this is a point at which volatile analytes could be lost andwill take all possible measures to reduce the exposure of these water samples thusminimizing volatilization of key analytes. After filling, both VOA vials will beappropriately labeled and prepared for shipment under chain-of-custody to the contractanalytical lab for independent quantification of TCE and the lesser-chlorinateddaughter products cis 1,2-dichloroethene (cis 1,2-DCE), and vinyl chloride (VC).

g:\env\proj\900\987 crane\work planVevised treatability workplan.doc 13


2.4.2 H2S, Perchlorate, Sulfate, Dissolved Iron and Manganese, and Nitrate Analysis

A second microcosm from each bottle set or treatment will be opened and the only twoanalytes sensitive to volatilization or exposure to atmospheric oxygen will be processedas rapidly as possible. Sufficient water to support the conduct of the HACHcolorimetric test for H2S will be withdrawn using a disposable syringe and the H2S testwill be conducted in the ARCADIS Treatability Laboratory. A dilution may be neededto bring the sample within analytical range. ARCADIS will determine pH and ORPwith respective probes and record the data. Next, a 20-mL sample will be withdrawnwith a disposable syringe and dispensed into an appropriately labeled containersupplied by an independent contract analytical laboratory for perchlorate analysis.Using the same disposable syringe, another 20-mL will be withdrawn and dispensedinto an appropriately labeled container [complete with the sulfuric acid (H2SO4)preservative] supplied by an independent contract analytical laboratory for dissolvedorganic carbon (DOC) analysis in accordance with EPA method 9060. Using the samedisposable syringe, 20-mL of water will be withdrawn. A 0.45 micron (u) syringefilter will be attached to the syringe and the sample will be filtered into a sample bottlepreserved with nitric acid (HNO3) and supplied by the independent contract analyticallaboratory to be submitted for dissolved iron and manganese analysis by USEPAMethod 601 OB. Lastly, ARCADIS will withdraw sufficient water and conduct aHACH colorimetric sulfate test. A dilution may be needed to bring the sample withinanalytical range.

2.4.3 Permanent Gas and Light Hydrocarbon Analysis

Permanent gases include methane (CH4), carbon dioxide (CO2), nitrogen (N2), andoxygen (O2). Light hydrocarbons of interest to this study include ethane and ethene.All of these dissolved gases are extremely volatile. Consequently, ARCADIS hasarranged for the shipment of an intact third microcosm from each bottle set to theindependent analytical contract laboratory. The contract laboratory will remove awater sample through the individual microcosm septa and inject the sample into itsown evacuated sample bottle where the permanent gases and light hydrocarbons willequilibrate with the headspace present and be analyzed by the USEPA approvedlaboratory SOP AM20GAX.

2.5 Bioaugmentation

Should headspace gas analysis plus at least one round of independent laboratoryaqueous phase analysis confirm that no treatment has occurred after 6 months of serum



bottle incubation, ARCADIS will commence with a bench-scale bioaugmentationevaluation. Should bioaugmentation become necessary, ARCADIS will inoculate thebiological control microcosm set (Bottle Set 2), and the high and low corn syrup bottlesets (Bottle Sets 3, and 4) with an appropriate reductive dechlorinator, such as theRegenesis product, Bio-Dechlor Inoculum(http://www.reeenesis.com/products/bd inoculum/) or equivalent. After inoculation,monitoring of microcosms headspace gas and aqueous contents will proceed aspreviously described above in Section 2.3 and Section 2.4.

3. Nano-scale ZVI Treatment of TCE and Perchlorate

This section describes a second column test designed to evaluate the potential forabiotic treatment of TCE and perchlorate. Nano-scale ZVI media is proposed for thisstudy. The batch testing program, also utilizing serum bottles, is intended to determinewhether the nano-scale ZVI media is capable of treatment of TCE and perchlorateunder the conditions present in groundwater at the Site (i.e., aerobic and high levels ofsulfates). This second batch test will be performed concurrently with the enhancedreductive dechlorination batch test outlined in the previous section.

3.1 Nano-scale ZVI Setting

Historically, conventional granular iron filings have been successfully utilized to treatchloroethenes during the application of reactive iron walls or permeable reactivebarriers. The chemical mechanism behind treatment of chloroethenes with ZVI is welldocumented (EPA/600-R-99/095a, September 1999). More recently, ARCADIS andCrane Co. have been working with "nano-scale" iron, which consists of ZVI particlesbest measured in nanometers rather than microns. The kinetic rate of treatmentassociated with nano-scale ZVI is much greater owing in part to a much higher surfacearea. Specifically, the ARCADIS Treatability Laboratory has been carrying out anano-scale ZVI research program funded by ESTCP(http://www.estcp.org/projects/cleanup/200017o.cfrn). This program is investigatingan in situ injection delivery mechanism that would ameliorate the depth limitationsimposed by trenching commonly associated with the conventional ZVI reactive walltechnology. Coincidently, a subsidiary of Crane Co. (Polyflon Company) is one of thesuppliers of nano-scale ZVI (PolyMetallix™ distributed by Nanitech LLC) that hasbeen analyzed during ARCADIS' ESTCP project.

ARCADIS and Crane Co. believe that the nano-scale ZVI in situ injection technologyis developed to the point that it is feasible at the site. Therefore, the Laboratory will



perform a series of tests intended to optimize the dose of Crane Co. nano-scale ZVInecessary to achieve closure levels for TCE, lesser chlorinated daughter products andperchlorate. ARCADIS and others have already generated some evidence forperchlorate reduction by nano-scale ZVI. This study will investigate the nano-scaleZVI dosage necessary to treat both COCs simultaneously. This study is not intended toinvestigate details associated with the physical interaction between nano-scale ZVI andsite-specific soils that pertain to injectability. These issues can be addressed for designpurposes based on geological analysis and knowledge of the transport properties of thenano-scale ZVI. They can then be verified in the future through field pilot testing.

3.2 Nano-scale ZVI Column Test Methodology

3.2.1 Procedure for Mixing Nano-scale ZVI and Site Soil

First, soil samples collected from the Site will be homogenized manually in stainlesssteel bowls with stainless steel implements. Prior to packing a column with a mixtureof nano-scale ZVI and site soil, the soil will be positioned on a wire bottom drainingframe to a standardized thickness of two inches and allowed to drain for exactly onehour. Next, the kinetic performance of the nano-scale ZVI to be used will bequantified for TCE and perchlorate in a series of aqueous batch tests using sitegroundwater. Kinetic data from the batch tests will be utilized to calculate threedosages of nano-scale ZVI for use during column testing. The kinetic data will alsopotentially influence the design of the column itself, particularly its length, whichdetermines contact time between the nano-scale ZVI and the COCs. The doses will bemeasured as weightvolume percentages (w/v). Initially, three columns are proposed.Estimated w/v relationships of site soil to nano-scale ZVI are estimated at 0.5%, 1%,and 2% nano-scale ZVI with soil. However these relationships may be adjusted afterbatch specific nano-scale ZVI kinetic data are collected as outlined above. Aftermanual mixing, the soil/nano-scale ZVI mixtures will be aged for one week in tightlypacked, airtight containers to allow the nano-scale ZVI to completely associate itselfwith the soil fraction.

3.2.2 Establishment of Soil Columns

The individual mixtures of soil and nano-scale ZVI will be used to fill glass columns.Throughout the treatability study, ARCADIS will consistently pack columns by addingthe soil or soil/nano-scale iron mixture to a column that is partly filled with water. This"submerged" packing technique aids in optimizing column packing to ensure that thecolumn is tightly packed. Past experience dictates tight column packing. If soil



columns are not tightly packed, shifting sands result and lead to physical conditionsthat are unrepresentative of the physical in situ setting that is being simulated.ARCADIS has estimated the length of the columns at 24 inches however; thisdimension may be updated based on nano-scale ZVI kinetics information. The weightof each empty column will be recorded in a bound laboratory notebook and all thecolumns will be vertically mounted. A small piece of glass wool will be packed intothe bottom of each column. Teflon™ tubing [1/8 inch outside diameter (OD)] will beconnected to the inlet and outlet of each column with stainless steel fittings. TheTeflon™ tubing emerging from the bottom of each column will transition to flexibletygon tubing to facilitate the use of a peristaltic pump. The length of flexible Tygon™tubing will be minimized due to its higher relative permeability to volatile chemicals.A peristaltic pump will be utilized to fill each column one-half full of site groundwater.After each column is one-half full of site groundwater, the soil/nano-scale ZVI mixturecorresponding to the column label will be spooned into the top of the column andallowed to settle through the groundwater. The Laboratory has found from extensivepast experience that this means of packing a column with soil insures that no air gapsremain after filling and commencing pumping operations. Soil will continue to beadded and allowed to settle through a layer of water until the soil displaces virtually allthe water present. A second small piece of glass wool will be inserted on top of thesoil column. If additional void space is present, it will be filled with a coarse, inert wellpack gravel. Each column will be sealed and its 1/8-inch OD Teflon™ effluent tubingwill be connected and inserted into a sample collection vessel. Tedlar bags of suitablesize will be used as both the untreated groundwater reservoir and the sample collectionvessels so as to minimize TCE volatilization. Figure 3-1 illustrates the experimentalapparatus for the nano-scale ZVI column study.



Effluent SampleCollection Vessel

(Tedlar Bag)

Glass wool

Sand packing

Soil/Nanoscale Iron Mixture

Influent Reservoir(Tedlar Bag)

PeristalticPump

Figure 3-1. Diagram of Nano-scale ZVI Column Test Apparatus

3.2.3 Soil Column Operation

After the columns are packed and sealed, a multi-head peristaltic pump will be used totransport site groundwater with concentrations of TCE and perchlorate that complywith the target concentrations outlined in Section 1.3 above through the individualcolumns in an upward flow pattern at a flow rate that simulates the groundwatervelocity at the site. A generic column void volume will be estimated based on thegeologic type of the site soil (i.e. sandy soil = 30% void volume). The estimated voidvolume will be used to track the number of pore space exchanges through the columns.Analytical samples for cVOCs (USEPA Method 8260) and perchlorate (USEPAMethod 314) will be collected for void volume 5, void volume 10, and void volume 15.Based on column dimensions (approximately 26 inches long and 1.75 inches indiameter) and a groundwater velocity assumption of 1 foot/day and assuming a 24-inchcolumn length, this translates into 33 days of operation. This operational interval toproduce 15 void volumes of effluent will need to be adjusted if the groundwater



velocity or column length is altered. The collected void volumes will be shipped to anindependent contract analytical laboratory for analysis. Pump flow will be temporarilyincreased during the collection of the void volume to be sampled to rapidly collect andpreserve the required sample volumes. This procedure is expected to have the effect ofrapidly collect a volume of water that is substantially less than the total column voidvolume, so the collected water will have been treated for the majority of its targetedresidence time within the column. Collection at the flow rate that scales to therepresentative groundwater flow velocity (approximately 0.01 mL/minute) is notrecommended for water containing volatile analytes of interest such as TCE andpotentially lesser (more volatile) chlorinated daughter products. Individual columnoperation will be discontinued should analytical results indicate substantial breakthrough of both cVOCs and perchlorate. In this event, additional column incorporatinga larger dose of nano-scale ZVI media may be considered.

4. Joint Nano-scale ZVI and Microbiologically Enhanced ReductiveDechlorination Treatability Study

4.1 Justification for Joint Investigation

In situ nano-scale ZVI remediation represents a new and exciting alternative for theremediation of perchlorate and cVOCs. Extensive study of the nano-scale ZVItechnology by ARCADIS and others has revealed its benefits and potentialshortcomings. While carbon substrate technologies that expedite cVOC andperchlorate treatment through microbiological means are feasible and in the case ofcVOCs, well demonstrated, they can require prolonged, multiple injections of thecarbon substrate being utilized ("Technical And Regulatory Requirements ForEnhanced In Situ Bioremediation Of Chlorinated Solvents In Groundwater-Final-December 23, 1998" Interstate Technology Regulatory Council and "A SystematicApproach to In Situ Bioremediation in Groundwater Including Decision Trees on InSitu Bioremediation for Nitrates, Carbon Tetrachloride, and Perchlorate, InterstateTechnology Regulatory Council, August 2002). Nano-scale ZVI remediation has thepotential advantage of requiring far less frequent injections provided the injectedproduct can be sheltered from disadvantageous oxidation by contact with DO, which ispresent in many aquifers including the Site. Due to the expense of nano-scale ZVI andthe inevitability of its partial consumption by a side reaction with DO in contaminatedgroundwater, ARCADIS is also proposing a treatability study intended to investigatethe merits of combining carbon substrate injections with nano-scale ZVI treatment toincrease the viable lifecycle of nano-scale ZVI treatment. In this treatability study,ARCADIS will investigate the potential benefits of using microbiology to precondition



aerobic groundwater prior to contacting the nano-scale ZVI treatment zone. Thepotential exists for a treatment paradigm including both microbiologically enhancedreductive dechlorination of TCE/perchlorate reduction and nano-scale ZVI treatment toexhibit synergism since both treatment regimes are demonstrated as effective on TCEand perchlorate at varying levels of application, and proceed under similar anaerobicconditions.

4.2 Joint Microbiology and Nano-scale ZVI Batch Test Methodology

This joint evaluation consist of a column study structured and carried out in much thesame way as the nano-scale ZVI only study previously described in Section 3. Duringthis study, ARCADIS intends to create one microbiologically active column that doesnot contain iron through the injection of corn syrup at the column inlet. Thismicrobiologically active column will be conditioned with corn syrup injection to thepoint that it is capable of eliminating DO and nitrate present in the representative sitegroundwater. Next, a second column similar in size and construction, but dosed withnano-scale ZVI during construction, will be linked to the microbiologically activecolumn. The nano-scale ZVI dosage adopted for this phase of the study will reflectconclusions from the nano-scale ZVI column testing described in Section 3. Aqueousanalytical samples for the quantification of COCs will be collected from both themicrobiological column effluent and the nano-scale ZVI column effluent forinterpretation.

4.2.1 Establishment of Microbiological Soil Column

First, soil samples collected from the Site will be manually mixed as described inSection 3.2.1 and loaded into a column according to the description above in Section3.2.2. The empty weight of the column will be recorded in a bound laboratorynotebook and the column will be vertically mounted. A small piece of glass wool willbe packed into the bottom of each column. Teflon™ tubing [1/8 inch outside diameter(OD)] will be connected to the inlet and outlet of the column with stainless steelfittings. The Teflon™ tubing emerging from the bottom of the column will transitionto flexible tygon tubing to facilitate the use of a peristaltic pump. The length offlexible tygon tubing will be minimized due to its higher relative permeability tovolatile chemicals. A peristaltic pump will be utilized to fill the column one-half fullof site groundwater. After the column is one-half full of site groundwater, thehomogenized soil will be spooned into the top of the column and allowed to settlethrough the groundwater. Soil will continue to be added and allowed to settle througha layer of water until the soil displaces virtually all the water present. A second small



piece of glass wool will be inserted on top of the soil column. If additional void spaceis present, it will be filled with a course, inert well pack gravel. The column will besealed and its 1/8-inch OD Teflon™ effluent tubing will be connected and inserted intoa sample collection vessel.

4.2.2 Microbiological Column Operation

After the column is packed and sealed, a peristaltic pump will be used to transport sitegroundwater with representative concentrations of TCE and perchlorate through thecolumn in an upward flow pattern at a flow rate that simulates the groundwater velocityat the site. A syringe pump will be used to dose the groundwater influent with a cornsyrup solution to induce microbiological activity. ARCADIS intends to operate thiscolumn until steady state operation results in the elimination of DO from the columneffluent. During the interval required to adjust the corn syrup dose, ARCADIS willmonitor concentrations of sulfate, dissolved iron, and TOC as well as pH and ORP inthe column effluent. It is possible that this period of the study will produce sometreatment of perchlorate and/or TCE.

4.2.3 Establishment of Nano-scale ZVI Soil Column

First, soil samples collected from the Site will be manually mixed as described inSection 3.2.1 and nano-scale ZVI will be mixed in at a ratio recommended from thecompletion of the completion of Section 3 of this study. The soil/nano-scale ZVImixture will be loaded into a column according to the description above in Section3.2.2. The empty weight of the column will be recorded in a bound laboratorynotebook and the column will be vertically mounted. A small piece of glass wool willbe packed into the bottom of each column. Teflon™ tubing [1/8 inch outside diameter(OD)] will be connected to the inlet and outlet of the column with stainless steelfittings. The Teflon™ tubing emerging from the bottom of the column will transitionto flexible tygon tubing to facilitate the use of a peristaltic pump. The length offlexible tygon tubing will be minimized due to its higher relative permeability tovolatile chemicals. A peristaltic pump will be utilized to fill the column one-half fullof site groundwater. After the column is one-half full of site groundwater, thehomogenized soil will be spooned into the top of the column and allowed to settlethrough the groundwater. Soil will continue to be added and allowed to settle througha layer of water until the soil displaces virtually all the water present. A second smallpiece of glass wool will be inserted on top of the soil column. If additional void spaceis present, it will be filled with a course, inert well pack gravel. The column will be



sealed and its 1/8-inch OD Teflon™ effluent tubing will be connected and inserted intoa sample collection vessel.

4.2.4 Joint Microbiological Column, Nano-scale ZVI Column Operation

After the microbiological column achieves substantial, steady state dissolved oxygen(DO) removal and ARCADIS understands the dose/response relationship between cornsyrup and DO and how this relationship affects the sulfur and iron balances within thecolumn, the nano-scale ZVI column will be connecting to the effluent of themicrobiological column using a short piece of 1/8 inch OD Teflon™ tubing. After 5calculated pore volumes have been transported through the entire system, ARCADISwill begin to collect aqueous analytical samples between the two columns and at theeffluent end of the nano-scale ZVI amended column. Analytes will include TCE anddaughter products (USEPA Method 8260), perchlorate (USEPA Method 314), sulfate,H2S, dissolved iron, TOC, pH, and ORP. Samples will be collected on void volumesrepresenting multiples of five up to fifteen pore volumes. Comparison of the analyticalresults for aqueous samples collected between columns and samples collected at theeffluent of the nano-scale ZVI column will delineate how the separate treatmentprocesses are affecting contaminant distribution in the samples. Figure 4-1 illustratesthe combined apparatus including both the microbiological column and the nano-scaleZVI column.

5. Schedule and Reporting Summary

The evaluation of microbiologically enhanced reductive dechlorination of TCE andperchlorate reduction described in Section 2 will require the greatest length of time tocomplete. This portion of the treatability study is dependent on bacterialacclimatization, growth rates, and kinetics. As such, ARCADIS can do little toexpedite the completion of this portion of the Treatability Workplan . It isconventionally assumed that batch tests such as that described in Section 2 above willrequire approximately six months to complete. The extension of this interval may bejustified by the collection of positive data during the first portion of the study.

During the incubation interval required for the microbiologically enhanced reductivedechlorination of TCE and perchlorate reduction, ARCADIS anticipates that it willcomplete the portions of the Treatability Workplan described in Section 3 and Section4. The evaluation of nano-scale ZVI is more easily expedited by aggressive staffing.However, the work described in Section 3 and Section 4 needs to be conducted in



series and its schedule is driven by simulation of groundwater flow velocities and thecollection of a set number of pore volumes from laboratory columns.

Upon completion of the treatability studies described in Sections 2, 3, and 4,ARCADIS will prepare a draft report, which summarizes the results. The report willincorporate data tables and graphics as required to communicate the outcome of theentire treatability study. Conclusions as to the objectives of the study will be made andincluded. The draft report will be submitted to both Crane Co. and USEPA Region 9for comment.

Microbiological Nanoscale IronColumn Column

Glass wool

Sand packing

Soil Mixture

Influent Reservoir(Tedlar Bag)

PeristalticPump

Effluent SampleCollection Vessel

(Tedlar Bag)

SyringePump

Figure 4-1. Joint Apparatus for Microbiological and Nano-scale ZVI Column Study



6. References

"A Systematic Approach to In Situ Bioremediation in Groundwater Including DecisionTrees on In Situ Bioremediation for Nitrates, Carbon Tetrachloride, andPerchlorate, Interstate Technology Regulatory Council, August 2002,http://www.itrcweb.org/common/default.asp.

Bradley, P.M., 2003. "History and Ecology of Chloroethene Biodegradation: AReview". Bioremediation Journal, Vol. 7, No. 2. p. 81-109.

Findlay, M. and S. Fogel "Microcosm Test for Natural Attenuation of ChlorinatedSolvents", 2000. Soil Sediment & Groundwater February/March, p. 13-16.

Moore, A.M., C.H. De Leon, and T.M. Young, 2003 "Rate and Extent of AqueousPerchlorate Removal by Iron Surfaces", Environmental Science &Technology,Vol. 37, No. 14, p. 3189-3198.

"Technical And Regulatory Requirements For Enhanced In Situ Bioremediation OfChlorinated Solvents In Groundwater-Final-December 23, 1998" InterstateTechnology Regulatory Council, December 1998,http://www.itrcweb.org/common/default.asp.

"Treatability Test for Evaluating the Potential Applicability of the ReductiveAnaerobic Biological In Situ Treatment Technology (RABITT) to RemediateChloroethenes" and produced under the Environmental Security TechnologyCertification Program,http://www.estcp.org/documents/techdocs/Rabitt Protocol.pdf.


ARCADISRevised TreatabilityWorkplan - In SituReactive Zone™Technology

Table 1-1. Data Parameters to be Analyzed during Microcosm Study SampleCollection

SampleMatrix

MicrocosmSoil Samples

MicrocosmGroundwater

Samples

Location

Field

Laboratory

Field

Laboratory

DissolvedOxygen

V

V

Oxidation/ReductionPotential

V

V

PH

V

V

Conductivity

V

V

SudanIV DyeTesting

V

VOCs

V

V

LightHydrocarbons

(Ethane &Ethene)

V

V

Alkalinity

V

V

DissolvedOrganicCarbon

V

Anions/Metals

V

V

Perchlorate

V


Proposed Location For IRZTreatability Study Sample Site.

Dry Well Location

Feet0 25 50 100 150 200

1:1,200

ARCADISinfrastructure, buildings, environment, communications

g:gis/987NewCrane/IF?ZTreatabi!ity.mxd

Site Plan Showing Proposed Location ofIRZ Treatability Study Sample Site

Phoenix-Goodyear Airport-North Superfund SiteGoodyear, Arizona

Figure

1-1

Documents

Revised treatability workplan - in situ reactive zone ... · Workplan - In Situ Reactive Zone™ Technology - Phoenix-Goodyear Airport - North Superfund Site, Goodyear, Arizona Prepared