PB97-963156
EPA/541/R-97/183
January 1998
EPA Superfund
Record of Decision Amendment:
Arlington Blending and Packaging
Arlington, TN
7/24/1997
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ARLINGTON BLENDING & PACKAGING
SUPERFUND SITE
AMENDED RECORD OF DECISION
July 1997
United States Environmental Protection Agency
Region IV
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TABLE OF CONTENTS
Section Page
THE DECLARATION I
DECISION SUMMARY 1
1.0 INTRODUCTION
1.1 Site Location
1.2 Affected Population
1.3 Adjacent Land Uses
1.4 Natural Resources
1.5 Site Operational History 3
1.6 U.S. EPA Enforcement Summary 3
1.7 Highlights of Community Participation 3
2.0 REASONS FOR ISSUING THE ROD AMENDMENT 4
2.1 Description of Original Selected Remedy 4
2.2 Rationale for Changing New Selected Remedy 6
3.0 DESCRIPTION OF NEW ALTERNATIVES 7
4.0 COMPARATIVE ANALYSIS OF NEW ALTERNATIVE REMEDIES 9
4.1 Overall Protection of Human Health and the Environment 9
4.2 Compliance with ARARS 9
4.3 Long-Term Effectiveness and Permanence 10
4.4 Reduction of Toxicity, Mobility or Volume through Treatment 10
4.5 Short-Term Effectiveness 11
4.6 Implementabiliry 11
4.7 Cost 11
4.8 State Acceptance 11
4.9 Community Acceptance 12
5.0 STATUTORY DETERMINATIONS 12
List of Figures
Figure 1 Site Location Map 2
Figure 2 Estimate J Extent of PCP Concentrations in Ground Water 5
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TABLE OF CONTENTS
APPENDICES
Appendix A - Tennessee Division of Superfund Letter of Concurrence
Appendix B - Summary of Cost Estimates for Evaluated Alternatives
Appendix C - Estimated Mass of PCP Contaminated Soils Remaining After Soil Excavations
Appendix D - Local Ordinances Regarding Well Installation and Water Withdrawal
Appendix E - Surface Water Dilution of COC's in the Loosahatchie River
Appendix F - Predicted Ground-Water Cleanup Times Using Modflow
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AMENDED RECORD OF DECISION
THE DECLARATION
SITE NAME AND LOCATION
Arlington Blending & Packaging Site
Arlington. Shelby County, Tennessee
STATEMENT OF BASIS AND PURPOSE
This decision document describes a fundamental change to the ground-water restoration approach presented in the
June 1991 Record of Decision (ROD) for the Arlington Blending & Packaging Site (Site). As the result of information
developed since the original ROD was finalized, EPA Region 4 has decided to employ monitored natural attenuation
as the new Selected Remedy. Site-specific characterization data indicated that shallow aquifer ground-water plumes
flowing beneath and downgradiem of the Site do not pose a realistic threat to human health or the environment. This
change to the original Selected Remedy was chosen in accordance with CERCLA, as amended, ana, to the extent
practicable, the National Oil and Hazardous Substances Pollution Contingency Plan (NCP), which states that natural
attenuation is generally recommended in special situations where ground-water is unlikely to be used in the foreseeable
future and therefore can be remediated over an extended period of time.
Further, EPA has determined that all physical construction related to this remedy has been completed. Therefore, the
site qualifies for inclusion on the Construction Complete List and this amendment to the ROD also serves as the
Preliminary Closeout Report. EPA Region 4 and the State of Tennessee Division of Superfund conducted a final
inspection on 11 April 1997, to verify that the Arlington Blending Site Group (the potentially responsible party) carried
out the provisions of the remedial action in accordance with the site remedial design plans and specifications.
The selection of monitored natural attenuation by EPA Region 4 for ground-water restoration at the Site does not
change the original ground-water performance standards (see Section 2.1). Thus, the goal of the Selected Remedy
remains to restore ground water to its beneficial uses by attaining remediation levels throughout the contaminant
plumes that have migrated beyond the edge of the area where contaminated site soils were excavated. This decision is
based on the administrative record for this site.
The State of Tennessee concurs with this amendment to the ROD.
RATIONALE FOR SELECTION OF NATURAL ATTENUATION AS GROUND-
WATER RESTORATION REMEDY
EPA Region 4 believes that the documented hazardous substances present in the shallow aquifer beneath this site do
not pose a current or likely future imminent and substantial endangerment to public health, welfare, or the
environment.
Therefore, even though the pump and treat remedy selected in the June 1991 ROD is an appropriate selected remedy,
its implementation is not necessary to protect human health and the environment. EPA Region 4 views the use of
monitored natural attenuation as a complement to the source control and soil treatment activities completed in July
1996 and the existing institutional controls in place at the Site. The following information has been obtained since the
original remedy was selected :
• The confining layer beneath the contaminated shallow aquifers has been confirmed to be intact beneath the area of
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ground-water contamination. The presence of this confining layer makes the possibility of vertical migration of
contaminants into the Memphis sand aquifer unlikely
the Loosahatchie River Canal (LRC) serves as a point of entry for site ground-water plume
ground-water contaminant levels are not substantial enough to adversely impact LRC water quality
41,431 tons of source (contaminated) soils were excavated and treated during early 1996 (more than ninety
percent of the total source soils)
existing Shelby County regulations prohibit construction of ground-water wells for domestic uses where a public
water system is available and within a half-mile of a listed Superiund cite; these regulations would, therefore,
preclude human exposure to the contaminated ground-water (for drinking water purposes) at any point between
the Site and the LRC
the shallow aquifer has not been used as drinking water source in the past and will not likely be used this purpose in
the foreseeable future
ground-water natural attenuation achieves cleanup standards within a time frame comparabUho that of active
aquifer restoration methods
STATUTORY DETERMINATION
Considering the new information that has been developed and the changes that have been made to the Selected
Remedy, USEPA believes that the remedy remains protective of human health and the environment and complies with
federal and state requirements that were identified in the June 1991 ROD as applicable or relevant and appropriate to
this remedial action at the time the original ROD was signed. However, this remedy does not satisfy the statutory
preference for treatment as a principle element because monitored natural attenuation was determined, by means of
ground-water modeling, to restore the shallow aquifer beneath the Site in a time frame comparable to that of pump and
treat.
Upon completion of this remedy, no hazardous substances will remain on-Site above health-based levels that prevent
unlimited use and unrestricted exposure. However, because this remedy requires greater than five years to achieve
these levels, pursuant to CERCLA section 121 (c), EPA must conduct a policy five-year review. The Five-Year
Review will be completed prior to June 2002 (five years after this ROD Amendment/ Preliminary Close Out Report
signature).
Richard D. Green, Acting Director Date
Waste Management Division
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DECISION SUMMARY
1.0 SITE NAME, LOCATION, AND DESCRIPTION
1.1 Site Location
The Arlington Blending & Packaging Superfund Site (ABAP or Site) is located in the town of Ailington,
Shelby County, Tennessee (Figure 1). The Site includes the 2.3 acre, former Arlington Blending &
Packaging Company grounds and the areal extent of ground-water contamination.
The site is located at 12121 U.S. Highway 70 in a lightly developed, somewhat rural seeing. A small
residential.area, known as the Mary Alice Drive Subdivision, is located adjacent to the eastern boundary of
the Site.
1.2 Affected Population
The Mary Alice Drive subdivision, is located adjacent and due east of the Site property line.
Approximately, 44 families reside within the subdivision. The subdivision is not located within the path
of the contaminated ground water addressed in this ROD. Potable water is provided to the subdivision by
the town of Arlington water department.
1.3 Adjacent Land Uses
The facility property is bordered on the south by CSX Railroad tracks: on the east by the Mary Alice Drive
subdivision; on the north by a sod grass farm; and on the west by a Tennessee Department of
Transportation facility. Currently, the portion of the Site where soil excavations took place is fenced on all
sides with a locked gate to minimize trespassing.
1.4 Natural Resources
Ground water occurs beneath the Site, in significant yields, from about 20 to 45 feet below surface.
Within this stratigraphic zone ground-water flows in a north to northwesterly direction towards the
Loosahatchie River Canal (LRC). The shallow aquifer is contaminated with pesticides and volatile organics
that resulted from former site operations. The next significant zone of water is encountered within the
upper portion of the Memphis sand aquifer, located at approximately 115 to 125 below ground surface.
An approximately 70 foot-thick sequence of confining clays and sandy clay is located between the shallow
aquifer and the Memphis sand aquifer.
The nearest surface water body, the LRC, is located approximately 3,000 feet due north of the Site. The
river is recognized by the State of Tennessee as being suitable for recreational purposes, wildlife,
irrigation, and livestock watering.
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Arlington, Tenn.
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SEWAGE
DISPOSAL
SCALE
2000 Fi.
Figure 1
Site Location Map
NORTH
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Arlington Blending & Packaging Sue
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1.5 Site Operational History
From 1971 to 1978 the Arlington Blending & Packaging (ABAP) Company operated as a pesticide
formulation and packaging facility (the Site). The ABAP Company blended technical grade pesticides
with solvents and emulsifiers and packaged the products for their client companies, which were primarily
pesticide manufacturers. During the company's operational period, spills and leakage of products handled
there occurred, resulting in the soil and ground-water contamination that was addressed in the 1991
Record of Decision (ROD).
1.6 U.S. EPA Enforcement Summary
In October 1983 EPA conducted an immediate removal which consisted of the excavation of 1920 cubic
yards of grossly contaminated surface soils (above 50 parts per million or ppm chlordane) and the removal
and disposal of all equipment and waste chemicals present at the Site. These actions were taken to address
surficial contamination that posed significant risk to human health.
The Site was proposed for inclusion on the National Priority List (NPL), as defined in Section 105 of
CERCLA? as amended, 42 U.S.C. § 9605, in August 1986. It was finally listed as an NPL site on July 1987.
EPA completed its Remedial Investigation and Feasibility Study a (RI/FS) in January 1991. The RI
detected pesticide contamination which included chlordane, heptachlor, endrin, pentachlorophenol (PCP),
and arsenic in site soils. Contaminants such as pesticides, PCP, and 1,1-dichloroethene were detected in
ground water above health based levels. Prior to undertaking the RI/FS, EPA formally requested, in
January 1988, that the identified Potentially Responsible Parties (PRPs) do so voluntarily. The PRPs
declined to conduct the RI/FS at that time.
The ROD was finalized in June 1991. In January 1992, EPA issued a Unilateral Administrative Order
(Section 106(a) of CERCLA, 42 U.S.C. §9606(a)) to the site PRPs which ordered them to implement the
1991 ROD. The PRPs agreed to do so under the collective title of Arlington Blending Site Group (ABSG).
The ABSG submitted the final Remedial Design Report, which addressed remediation of site soils, to EPA
in January 1994.
In order to implement the soils remediation plan, it was necessary to issue an Explanation of Significant
Differences (ESD) to the 1991 ROD to document significant changes to the soils remedy outlined in the
ROD. Primarily, the ESD changed the maximum vertical excavation boundary to that of the water table
and also limited the horizontal excavation boundary at the back of the Site to that of the railroad track.
Site soils remediation was conducted from January to July 1996 and consisted of the excavation and
treatment of 41,431 tons of subsurface and surficial soils contaminated above 3.3 parts per million (ppm)
chlordane, 0.6 ppm endrin, or 0.6 ppm pentachlorophenol.
1.7 Highlights of Community Participation
In accordance with CERCLA, Section 117 and NCP 300.435(c)(2)(ii) a revised proposed plan was mailed
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Arlington Blending & Packaging Siie
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to interested parties and other persons who have requested to be included on EPA's mailing list for the
Site. The proposed plan supporting information was made available to the public in the information
repository maintained at the EPA Docket Room in Atlanta and at the Arlington Public Library. Notice of
availability of these documents was published in the Commercial Appeal on June 19, 1997. A comment
period of thirty days was provided to receive written or oral comments from the public from June 18, 1997
to July 18,1997. No comments were submitted to EPA regarding the amendment to the ROD.
2.0 REASONS FOR ISSUING THE ROD AMENDMENT
2.1 Description of the Original Selected Remedy
The original selected remedy (1991 ROD) contained both a soil and ground-water component. The
objective of the soil remediation was two fold: to excavate surficial soils that posed risk to humans as the
result of dermal exposure or consumption and to excavate subsurface soils determined to be a source of
ground-water contamination. The goal of the ground-water portion of the selected remedy was to restore
contaminated ground water, contained in the site shallow aquifer, to drinking water quality.
The soils remediation was started in January 1996 and completed in July 1996. Thermal desorption was
utilized to remove contaminants (primarily pesticides) from the soils by heating the soils in order to
vaporize the contaminants into an off-gas stream. The volatilized contaminants were recovered by routing
the off-gas stream through to a granulated activated carbon air pollution control system.
The 1991 ROD stated that contaminated ground water would be restored to drinking water quality by
utilizing a series of ground-water wells to extract the identified ground-water contaminant plumes and
treating the recovered water with granular activated carbon. Effluent from the carbon adsorption units was
to be discharged to the to the town of Arlington Publicly Owned Treatment Works (POTW) facility or to
the LRC. The ROD specified that Maximum Contaminant Levels (MCLs) under the Safe Drinking Water
Act be established as cleanup standards for site ground water, reducing levels of benzene, chlordane, 1,1-
dichloroethene (1,1-DCE), endrin, pentachlorophenol (PCP), and heptachlor epoxide to MCLs of 5.0 ^g/c,
2.0 j.
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AB-15D
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AB-16D 34.7
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<20.0
Figure 2
Estimated Extent of POP Concentrations
Based on May 18,1995 Sample Date
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2.2 Rationale for Changing the Selected Remedy
In light of new site-specific data that has been obtained or developed since the 1991 ROD was finalized, EPA
Region 4 now believes that monitored natural attenuation, rather than extraction, is the appropriate remedy
for restoration of ground water contained in the Site's shallow aquifer. This approach will be fully protective
of human health and the environment and will attain cleanup levels within a reasonable time frame.
There are no compelling factors that favor rapid restoration of the impacted shallow aquifer, since the aquifer
ground water is not currently used for domestic purposes and will not. realistically, be consumed in the future.
Therefore, the fact that monitored natural attenuation may take longer to achieve ground water cleanup
standards, than the most efficient pump-and-treat alternative, does not disqualify it as a remedial alternative.
In the 1991 ROD, the impacted shallow aquifer ground water was classified as IIB (potential drinking
water aquifer) primarily as the result of its non-saline characteristics and volumetric yield. This
designation was supported by the lack of adequate site-specific data regarding the degree of hydraulic
separation between the shallow aquifer ground water and the ground water in the Memphis sand aquifer
(the primary source of potable water in the area). Therefore, EPA conservatively assumed that the surficial
aquifer ground water potentially threatened the Class HA ground water contained in the deeper Memphis
sand aquifer. The absence of a confining layer would have increased the possibility that releases from the
Site might adversely impact the Memphis sand aquifer, as the result of vertical leakage. EPA chose a
pump-and-treat remedy as the means to actively restore the IIB shallow aquifer ground water to drinking
water quality, in accordance with its Ground-Water Protection Strategy policy.
Since the original remedy was selected, the following information has been gathered to better characterize
ground-water contamination in the shallow aquifer: (1) the shallow aquifer was determined to be
hydraulically separated from the Memphis sand aquifer located below it; (2) the impacted ground water
was determined to discharge into the Loosahatchie River Canal (LRC); (3) ground-water contaminant
concentrations were determined to not adversely impact LRC surface water quality (i.e., do not exceed
NPDES surface water discharge limits); (4) approximately 41,431 tons of contaminated source soils were
excavated for treatment; (5) there are no downgradient receptors; and (6) existing Shelby County
regulations prohibit construction of ground-water wells in proximity of the Site.
Additionally, EPA Region 4 conducted a ground-water modeling analysis in October 1996 to reevaluate
the appropriateness of pump and treat as a means to achieve ground-water restoration following the 1996
site soil excavations. The analysis indicated that utilization of natural attenuation will attain ground-water
cleanup within a reasonable time frame, compared to the cleanup time frame required by pump and treat,
when biodegradation processes are considered. For instance, monitored natural attenuation was predicted
to restore ground water to remediation levels within 28 years, while the two ground-water pump-and-treat
alternatives evaluated for this ROD amendment attained cleanup levels within approximately 20 years
(Appendix F).
The impacted shallow aquifer ground water poses no direct threat of future risk to lifetime residents and
adult workers at the Site. The impacted shallow ground water poses no hydrogeological threat to water
quality in the Memphis sand aquifer, nor to the LRC (Appendix E).
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3.0 DESCRIPTION OF NEW ALTERNATIVES
Based upon consideration of the requirements of CERCLA, the NCP, and the detailed analysis of
alternatives, EPA reviewed a total of four (4) ground-water restoration options for this ROD amendment to
evaluate the feasibility of this option in light of new information that has been obtained since the original
ROD was finalized.
Alternatives 1. 2, and 3 are variations of the original remedy, which stated that pump and treat would be
utilized to restore ground water to levels protective of human health. The alternatives listed below were
evaluated and compared to the nine criteria, as required by the NCP. EPA Region 4 has selected Alternative
4 as its preferred remedy which is estimated at S 2,220,000 in present worth over thirty-five years. This
response action will address the contaminated shallow ground water by allowing adsorption, biodegradation,
dilution, and/or dispersion to effectively reduce contaminants to protective levels. Alternatives 1 and 2
involve employing on-site recovery wells to recover impacted ground water, but differ in the orientation of the
off-site recovery wells. Alternative 3 involves limiting shallow ground-water extraction to on-site wells and
docs not address portions of the plume that have migrated off site.
Alternative 4 primarily consists of monitoring of contaminated ground water in the surficial aquifer beneath
and adjacent to the Site and utilizing institutional controls to protect humans from exposure until protective
levels are reached. An annual sampling of the city water supply for site contaminants of concern and a survey
of wells constructed within a one mile radius of the Site will be required under this alternative. Also surface
water sampling would be conducted in the threatened portion of the LRC in order to provide empirical
assurance that stream water quality is not adversely impacted by the contaminant plume.
Remedial Alternative 1: Ground-Water Restoration using Both On-Propcrty Recovery Wells and
Off-Property Wells Oriented Parallel Path of Contaminant Plume Axis
Capital Cost: $1,533,600
Annual O&M Cost: $302,300
Present Worth: $7,739,400 (35 years at 4%)
Time to Construct: Less Than One Year
This alternative involves recovering impacted ground water using a series of extraction wells installed in the
shallow aquifer. Each recovery well would be fined with a submersible pump connected to a header pipe that
discharges to a treatment system, such as activated carbon adsorption columns. Treated water would be
discharged to the LRC or Arlington POTW. An estimated four (4) extraction wells on site property and an
estimated three (3) wells would be placed off-site across the sod farm property to the north. The off-site
extraction well*: would be oriented parallel to the path of the contaminant plume. An estimated five (5) wells
would be installed to evaluate plume contaminant levels.
Annual sampling of ground water and report of the results would be conducted throughout the remediation
period and for the five year period after remediation was completed.
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Remedial Alternative 2: Ground-Water Restoration using Both On-Property Recovery Wells and
Off-Property Wells Oriented Perpendicular to Patb of Contaminant Plume Axis
Capital Cost: S2,028,200
Annual O&M Cost: $302,300
Present Worth: $8,798,100 (35 years at 4%)
Time to Construct: Less Than One Year
This alternative involves recovering impacted ground water using a series of extraction wells installed in the
shallow aquifer. Each recovery well would be fitted with a submersible pump connected to a header pipe that
discharges to a treatment system. Treated water would be discharged to the LRC or Arlington POTW. An
estimated four (4) extraction wells on site property and an estimated eight (8) wells would be place off-site
across the sod farm property to the north. The off-site extraction wells would be oriented.perpendicular to the
path of the contaminant plume. An estimated five (5) wells would be installed to evaluat6 plume contaminant
levels. Sampling and reporting procedures followed for this alternative would be the same as those described
in Alternative 1.
Remedial Alternative 3: Ground-Water Restoration using On-Property Wells and Monitored Natural
Attenuation of Off-site Plume
Capital Cost: $1,024,400
Annual O&M Cost: 302.260
Present Worth: $5,641,600 (35 years at 4%)
Time to Construct: Less Than One Year
This alternative involves recovering impacted ground water using a series of extraction wells installed in the
site shallow aquifer. Each recovery well would be fitted with a submersible pump connected to a header pipe
that discharges to a treatment system (i.e. activated carbon adsorption columns). Treated water would be
discharged to the LRC or Arlington POTW. An estimated four (4) extraction wells would be installed on
site property, with no off-site wells. An estimated five (5) wells would be installed to evaluate plume
contaminant levels. Sampling and reporting procedures followed for this alternative would be the same as
those described in Alternative 1.
Remedial Alternative 4: Monitored Natural Attenuation
Capital Cost: $21,600
Annual O&M Cost: $117,800
Present Worth: $2,220,000 (35 years at 4%)
Time to Construct: Less Than One Year
This alternative involves installing approximately five new monitoring wells at the Site to evaluate ground-
water plume contaminant levels. Ground-water monitoring data would be reviewed annually to evaluate
ground-water quality. The annual monitoring plan would include the following: (1) annual collection of
water sample from city water supply for analysis; (2) annual well survey of wells installed within a 1-mile
radius of the Site to identify wells installed since the previous survey; (3) annual sampling and analysis of
LRC surface water; and (4) annual sampling and analysis of site monitoring well data.
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4.0 COMPARATIVE ANALYSIS OF NEW ALTERNATIVE REMEDIES
US EPA Region 4 has reconsidered the Selected Remedy presented in the June 1991 ROD. This section
profiles Alternative 4, which the Agency is now selecting, compared to the other alternatives that were
evaluated, using the nine criteria.
THE ANALYSIS
Threshold Criteria
4.1 Overall Protection of Human Health and the Environment
Overall protection of human health and the environment addresses whether each altemasrve provides
adequate protection of human health and the environment and describes how risks posed through each
exposure pathway are eliminated, reduced, or controlled, through treatment, engineering controls, and/or
institutional controls.
Each of the ground-water recovery alternatives provides comparable protectiveness to human health and the
environment. Since the shallow aquifer is hydraulically isolated from the Memphis sand aquifer located
below it, contaminated ground-water flowing through the shallow aquifer poses no current risk or plausible
future risk to those who utilize the Memphis sand aquifer for potable water.
A subsurface investigation of the geology beneath the sod farm was conducted in April 1996 to determine the
lateral thickness and the vertical permeability of the clay confining unit above the Memphis sand aquifer.
The investigation determined that the confining layer is uniformly contiguous beneath the property where the
site plumes have migrated.
Further, existing county and State regulations prohibit the siting of domestic ground-water wells for a number
of reasons, such as the availability of a publicly supplied water system, proximity to a Superfund site, and
flood plain construction restrictions. Thus, no reduction in carcinogenic risk is realized as the result of
ground-water extraction measures relative to that of natural attenuation measures.
The surficial aquifer ground water was determined to discharge into the Loosahatchie River. The discharge
poses no adverse impact to the river because ground-water contaminant levels are diluted below applicable
ambient surface water levels.
4.2 Compliance with ARARs
Compliance with ARARs addresses whether a remedy will meet all of the applicable or relevant and
appropriate requirements of other Federal and State environmental statutes or provides a basis for invoking a
waiver.
The only ARARs for this Site are the maximum contaminant levels (MCLs), established under the Safe
Water Drinking Act, for ground water that is, or may be used, for drinking. Each of the alternatives comply
with ARARs since contaminant concentrations will be reduced below MCLs over time. Each of the
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alternatives requires an extended period of time to achieve health based levels in downgradient monitoring
wells. EPA's analysis of the each alternative's aquifer restoration time frame indicated that health-based
levels could be achieved at compliance wells within comparable time frames of thirty years or less, when
biodegradation was factored into estimated cleanup time assumptions.
The ground-water extraction systems described in Alternatives 1,2, and 3 would primarily be subject to the
state regulations that involve ground-water withdrawal and the discharge of treated water to the Loosahatchie
River under state NPDES surface water discharge regulations or town Arlington POTW guidelines. Each of
these alternatives would comply with the state's ground-v. ater withdrawal and state NPDES requirements.
The alternatives would also comply with applicable flood plain design and hazardous materials transportation
requirements.
Primary Balancing Criteria
4.3 Long-Term Effectiveness and Permanence
Long-term effectiveness and permanence refer to expected residual risk and the ability of a remedy to
maintain reliable protection of human health and the environment over time, once cleanup levels have been
met This criterion includes the consideration of residual risk and the adequacy and reliability of controls.
Alternatives 1, 2, and 3 would actively remove contaminants from impacted ground water and retard the
migration of the site related contaminant, thereby permanently eliminating the potential for the recovered
contaminants to threaten human health and the environment All of the ground-water extraction alternatives
should eventually provide a permanent remedy for ground water.
Alternative 4 does not actively reduce the level of contaminants in the site-related ground-water plumes.
Rather, it relies on natural processes (i.e., biodegradation, dilution, dispersion, adsorption, and chemical
degradation) to reduce contaminant concentrations. However, the impacted shallow aquifer containing the
plumes has not in the recent past, currently, or will not in the foreseeable future be used for domestic
purposes.
The impacted ground-water poses no risk to human health as the result of ingestion. The shallow aquifer
discharges into the Loosahatchie River Canal (LRC) which is located approximately 3000 feet downgradient
of the Site. Ground-water contaminants discharged to the LRC would be diluted to below applicable ambient
water quality levels for Tennessee surface waters. Additional monitoring wells would be installed to monitor
plume contaminant levels for increases mat may adversely impact the LRC.
4.4 Reduction of Toiicity, Mobility or Volume through Treatment
Reduction of toxicity, mobility, or volume through treatment refers to the preference for a remedy that uses
treatment to reduce health hazards, contaminant migration, or the quantity of contaminants at a site.
Alternatives 1 and 2 involve extraction of contaminant plume both onsite and off site, while Alternative 3
would limit ground-water extraction to on-site wells. Alternative 3 would employ monitoring wells within the
path of the off-site plume.
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Alternative 4 will not actively reduce the mobility, toxicity, or volume of the site-related ground-water
plumes, even though ground-water restoration eventually is predicted as the result of natural attenuation.
This alternative will incorporate regular monitoring to gauge the progress of plume contaminant levels
compared to site performance standards. Constituent concentrations within the plumes are expected to
decrease with time, since more than 90 percent of the contaminated source soils have been removed
Alternatives 1,2, 3, arid 4 are predicted to attain remdiation levels within 21 years, 19 years, 29 years, and
28years. respccitvely.
4.5 Short-Term Effectiveness
Short-term effectiveness refers to the period of time needed to complete the remedy and any adverse impacts
on human health and the environment that may be posed during the construction and implementation of the
remedy.
Construction activities associated with Alternatives 3 and 4 would be limited to the Site, while Alternatives
land 2 would involve construction on the sod farm property. As a result, there should be no adverse effects
to the community. Short-term effects to on-site workers involved in the construction should be minimal.
However, health and safety procedures will be implemented during the construction as a precaution. The time
required for implementation of these alternatives is expected to be less than one year. There are no short term
threats associated with the Selected Remedy that cannot be readily controlled. In addition, no adverse cross-
media impacts are expected from the remedy.
4.6 Implement ability
Treatment equipment associated with Alternatives 1,2, and 3 is readily available from multiple vendors.
Similarly, the installation of additional monitoring wells, extraction wells, and related piping, can be
accomplished easily for each of the alternatives. •
4.7 Cost
A comparison of present worth costs associated with the ground water alternatives indicates that Alternative
4 is the least expensive (52,219,920), followed by Alternative 3 (56,666,000), followed by Alternative 1
(57,739,350) and Alternative 2 (57,798,100). Capital costs will be much higher for Alternative 2
(52,028,200) compared to Alternatives 1, 3, and 4 (51,533,600, 51,024,420 and 521,600, respectively).
Annual O&M costs will be approximately equal for Alternatives 1, 2, and 3 (5302,260 and considerably less
for Alternative 4 at 5177, 800.
MODIFYING CRITERIA
4.8 State Acceptance
The State of Tennessee concurs with this amendment to the 1991 ROD. The State's reasoning focused on the
recent source removals and confirmation of an existing confining layer beneath the Site and ground water as
the basis for their concurrence. See Appendix A.
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4.9 Community Acceptance
No public comment was submitted to EPA regarding the ROD Amendment.
5.0 STATUTORY DETERMINATIONS
Under its legal authorities, EPA's primary responsibility at Superfund sites is to select remedial actions that
are protective of human health and the environment In addition, Section 121 of CERCLA established
several other statutory requirements and preferences. These specify that when complete, the selected
remedial action for a site must comply with applicable or relevant and appropriate environmental standards
established under Federal and State environmental laws unless a statutory waiver is granted. The selected
remedy must also be cost-effective and utilize permanent treatment technologies or resource recovery
technologies to the maximum extent practicable. Finally, the statute includes a preference for remedies that
permanently and significantly reduce the volume, toxicity, or mobility or hazardous wastes.
Considering the new information that has been developed and the changes that have been made to the selected
remedy, USEPA believes that the remedy remains protective of human health and the environment, complies
with federal and state requirements mat were identified in the June 1991 ROD as applicable or relevant and
appropriate to this remedial action. In addition, the revised remedy utilizes permanent solutions and
alternative treatment technologies to the maximum extent practicable for this site.
-------
APPENDIX A
CNJ
O
CD
ON
-------
b 9 0025
APPENDIX A
State of Tennessee Concurrence Letter
-------
b 9 0026
STATE OF TENNESSEE
DEPARTMENT OF ENVIRONMENT AND CONSERVATION
Division of Superfund
401 Church Street
4th Floor, L&C Annex
Nashville, TN 37243-1538
May 22,1997
Mr. Derek Matory
Environmental Project Manager
United States Environmental Protection Agency
Region 4
Atlanta Federal Center
100 Alabama Street, S.W.
Atlanta, Georgia 30303-3104
Re: Concurrence for the Amended Record of Decision Proposed Plan for the Arlington Blending &
Packaging site, Arlington, Shelby County, Tennessee, June 1997, TDSF #79-503
Dear Mr. Matory:
The Tennessee Division of Superfund (TDSF) has reviewed the draft Amended Record of Decision
Proposed Plan for the Arlington Blending & Packaging site, Arlington, Shelby County, Tennessee, dated
June 1997, sent under cover on 5/8/97.
The Tennessee Department of Environment and Conservation (TDEC) is in concurrence with the
amended remedy, Alternative 4, Monitored Natural Attenuation. New information has been provided
regarding the subsurface transport mechanisms, in particular confirmation of the existence of a
substantial confining unit beneath the Site and groundwater. Source removals conducted at the Site in
Operable Unit 1 have also served to significantly diminish source contribution to the groundwater plume.
Time frames for Natural Attenuation, although longer than pump and treat scenarios, are generally
within the same order of magnitude. Factors included in the concurrence with this alternative included:
short term risks, cost, and local enterprise impacts.
Please let us know if we can be of further assistance.
Sincerely.
Kenneth W. Bunting, Director
Tennessee Division of Superfund
cc: TDSF, NCO file
TDSF, MFO file
fodoonifli
-------
APPENDIX B
o
o
...o
-------
5 9 0023
APPENDIX B
Summary of Cost Estimates for Evaluated Alternatives
-------
ARLINGTON BLENDING SITE
Groundwater Treatment System
Summary of Cost Estimates
(Based on Revisions to BCM's Estimate)
Intrinsic Remediation
Capital Cost
Monitoring Wells
O&M
35 Years, 4% rate, $117,780/year
21,600
2.198.318
Total Cost - Intrinsic Remediation $ 2,219,918
AttemativeXfUSEPAl
On-Property Recovery Wells
and 3-Oowngradient Wells
Parallel to Plume Axis
Capital Cost
Treatment Plant ($762,841 + 20%) -
GW Extraction System (on-property)
GW Extraction System (off-property)
Monitoring Wells
Subtotal Capital Cost
** Note: Allow 20% for additional treatment capacity
915,409
239,976
356,640
21.600
O&M
35 Years, 4% rate, ($302,260 +10%) /year *
* Note: Allow 10% for additional maintenance
1,533,625
6.205.723
Total Cost-Alternate7 $ 7,739.348
Alternative YTOSEPA1
On-Property Recovery Wells
and 8-Downgradient Wells
Perpendicular to Plume Axis
Capital Cost
Treatment Plant ($762,841 + 50%) "
GW Extraction System (on-property)
GW Extraction System (off-property)
Monitoring Weds
** Note: Additional Treatment Capacity
for 8 Additional Wells
O&M
35 Years. 4% rate. ($302,260 + 20%) /year *
'Note: Allow 20% for additional maintenance
$ 1,144,262
239,976
622,368
21.600
Subtotal Capital Cost 2,028,206
6.769.879
Total Cost - Alternate 8 $ 8,798,085
GWTRREV.XLS
11/20/96
Pagel
-------
ARUNGTON BLENDING SITE
Groundwater Treatment System
Revision of Cost Estimate Provided by BCM
Kern Description
Treatment Plant
Groundwater Collection Tank
Dynasand Filter with Carbon
Polishing Carbon Filter
Compressor
Bag FBter
Effluent Tank
Backwash Tank w/ag'rtation
Pumps
Control Panel
Instrumentation
Control Software
Control PC
Control Software Programming
Piping
Ancillary Systems
Electrical
Treatment Building (40)
Pad Improvements + Foundation
Quantity
1
1
1
1
1
1
1
6
1
'1
1
1
1
1
1
1.200
1
Units
Each
Each
Each
Each
Each
Each
Each
Each
Each
Each
Each
Each
Each
Each
Each
Sq. Ft.
Each
Material
Cost
tt/unit)
$ 4,000
62,000
5,000
3,500
2,000
4,000
5,000
1,000
10,000
70,000
6,000
2,500
15,000
40,000
20,000
28
20,000
Installation Total
Cost Installation
fS/unitt Cost
$ 1,000 $ 5,000 $
20,000 82,000
3,000 8,000
1,000 4,500
1,000 3,000
1,000 5,000
1,000 6,000
300 1,300
5,000 15,000
20,000 90,000
200 6,200
200 2,700
15,000
15,000 55,000
Treatment Plant Subtotal
15,000 35,000
28 56
20,000 40,000
Ancillary Systems Subtotal
Subtotal
2% Allowance for Contractor Bonding and Insurance
3% Allowance for MobTDemob.
Subtotal
20% Allowance for Engineering, Legal and Construction Services
Subtotal
Contingency 20%
Commissioning and startup
Total
Cost
5,000
82,000
8,000
4,500
3,000
5,000
6,000
7,800
15,000
90,000
6,200
2,700
15,000
55,000
305,200
35,000
67,200
40,000
142,200
447,400
8,948
13,422
469,770
93,954
563,724
169,117
30,000
Estimated Total Treatment Plant Cost $ 762.841
GWTRREV.XLS
11/20/96
Page 2
-------
Hem Description
Extraction System (on Property)
Collection Pipe (273" HOPE)
Discharge Pipe (1 1/273" HOPE)
WeB Installation
WeO Pump
Valve box
Electrical
Extraction System (Alternative"*)
Collection Pipe (2"/3" HOPE)
Discharge Pipe (Increase to 476")
Highway Tunneling
Well Installation
Wed Pump
Valve box
Electrical
Extraction System (Alternative^
Collection Pipe <2Y3" HOPE)
Discharge Pipe (Increase to 476")
Highway Tunneling
Wen Installation
WeV Pump
Valve box
Electrical
lantity
750
3,230
4
4
4
700
Units
LF.
LF.
Each
Each
Each
LF.
20% Allowance
Material
Cost
(S/unit)
$ 25
30
5,000
2,000
4,000
10
for Engineering,
Installation Total
Cost Installation
Wunitt Cost
$ - $ 25 $
30
5,000
2.000
4,000
10
Subtotal
legal and Construction Services
Subtotal
Contingency 20%
Total Extraction System (On-Property) $
3,000
3,230
50
3
3
3
3,000
20% At
L.F.
LF.
LF.
Each
Each
Each
LF.
lowance
30
40
300
5,000
2,000
4,000
10
for Engineering,
*
^
•»-.
30
40
300
5,000
2,000
4,000
10
Subtotal
legal and Construction Services
Subtotal
Contingency 20%
Total Extraction System (Off-Property) $
5,000
3,230
50
8
8
8
5,000
LF.
LF.
LF.
Each
Each
Each
LF.
20% Allowance
30
40
300
5,000
2,000
4,000
10
for Engineering,
30
40
300
5.000
2,000
4,000
10
Subtotal
legal and Construction Services
Subtotal
Contingency 20%
Total Extraction System (Off-Property) $
Total
Cost
18,750
96,900
20,000
8,000
16,000
7,000
166,650
33,330
199,980
39,996
239,976
90,000
129,200
15,000
15,000
6,000
12,000
30,000
297,200
59,440
297,200
59,440
356,640
150,000
129,200
15,000
40,000
16,000
32,000
50,000
432,200
86,440
518,640
103,728
622,368
GWTRREV.XLS
11/20/96
Page 3
-------
Material Installation Total
Cost Cost Installation Total
item Description Quantity Units fS/unrtt (S/unitt Cost Cost
Monitoring System
Well Installation 6 Each 2.500 - 2.500 15.000
Subtotal 15,000
20% Allowance for Engineering and Construction Services 3,000
Subtotal 18,000
Contingency 20% 3,600
Total Monitoring System $ 21.600
GWTRREVJCLS 11/20/96 Page 4
-------
Item
Labor Requirements
Engineering and Management
Oversight
Engineering (data + reports)
EPA Oversight
Utilities
Electricity
Water
Phone
Maintenance
Site Maintenance
Fertilizing
Mowing
O&M (no treatment)
ARLINGTON BLENDING SITE
Intrinsic Remediation
Projected Annual O&M Costs
Quantity
Sampling Technician - wells
Analytical
GW chemical monitoring
VOC's
BNA's
Pesticides
Metals (As)
Inorganics
18
18
18
18
18
Usage
Rate
8 hour/day
1 sample/year
1 sample/year
1 sample/year
1 sample/year
1 sample/year
8 hour/day
8 hour/day
Operating Unit
Schedule Cost
10 day/year $40/hour
Subtotal Labor
1 sample/year 185
1 sample/year 375
1 sample/year 150
1 sample/year 50
1 sample/year 200
Subtotal Analytical
30 days/year 90
60 days/year 90
Annual
Cost
$ 3,200
3,330
6,750
2,700
BOO
3,600
21,600
43,200
Subtotal Engineering and Management
1 /year
//
1 /year
1 /year
1 /year
1 /year
1 /year 20.000
Subtotal EPA Oversight
1 /year 1,000
1 /year 500
1/year 1,000
Subtotal Utilities
1 /year 10,000
Subtotal Maintenance
4 times/year 1 ,000
8 times/year 500
20.000
1,000
500
1,000
10,000
4,000
4,000
Total
Annual Cost
3,200
17,280
64,800
20,000
2,500
10,000
Subtotal Site Maintenance 8,000
Total Annual O&M Estimated Cost $ 117.780
GWTRREV.XLS
11/20/96
Page 5
-------
ARLINGTON BLENDING SITE
Groundwater Treatment System
Projected Annual O&M Costs
Item
System Operator
Sampling Technician - plant
Sampling Technician - wells
Analytical
G W chemical monitoring
VOC's
BNA's
Pesticides .
Metals (As)
Inorganics
System Monitoring
VOC's -
BNA's
Pesticides
Metals (As)
Inorganics .
Engineering and Management
Oversight
Engineering (data + reports)
EPA Oversight
Utilities
Electricity
Water
Phone
Supplies
Activated Carbon
Filters and disposal
Maintenance
Quantity
18
18
18
18
1 8
5
5
5
5
5
Usage Operating Unit
Rate Schedule Cost
8 hour/day 365 days/year $20/hour
8 hour/day 1 day/month 40/hour
8 hour/day 4 dav/vear 40/hour
Subtotal Labor
. 1 sample/year 1 sample/year 185
1 sample/year 1 sample/year 375
1 sample/year 1 sample/year 150
1 sample/year 1 sample/year 50
1 samole/vear 1 sample/year 200
1 sample/quarter 4 quarters/year
1 -sample/quarter 4 quarters/year
1 sample/quarter 4 quarters/year
1 sample/quarter 4 quarters/year
1 sample/Quarter 4 auarters/vear
Subtotal
8 hour/day 48 days/year
8 hour/day 45 days/year
Subtotal
185
375
150
50
200
Subtotal
Analytical
90
90
Subtotal Engineering and Management
1 /year
1 /year
1 /year
1 /year
1/dav
1 /year
1/vear 20.000
Subtotal EPA Oversight
1 /year
1 /year
.1 /year
24,000
2.000
2.000
Subtotal Utilities
2 changes/year
365 days/year
15.000
20
Subtotal Supplies
1 /year $50.000
Subtotal Maintenance
Annual
Cost
58,400
3.840
1.280
3,330
6.750
2.700
900
3.600
17.280
3.700
7,500
3,000
1,000
4.000
19.200
34.560
32.400
20.000
24,000
2,000
2.000
30,000
7.300
$ 50.000
Total
Annual Cost
63,520
36,480
66,960
20,000
28,000
37,300
50.000
Total Annual O&M Estimated Cost $ 302,260
GWTRREV.XLS
11/20/96
Page 6
-------
MAR-18-97 TUE 13:41
P. 02
Arlington Blending She
Oroundwater Treatment System
Summary of Cost Estimate*
Intrinsic Remediation
"*\
CapHaTCost
^
O&M
^x-"*
[Based on Revisions to SCOTS Estimate)
WoottOrirXJ Wells
"^v^
^->.
^''^
^^^
^^"
35 Yeare, 4% rett>$tr7,780/yr.
^"^C ^-^ i
^ — ^ Total Cost -Intrinste-Remediation
On-Property Recover r
Treatment System
Capital Cost
O&M
bn-Property and
Off-Property Recover
Mfcatmtnt System
\
C&p&alCost
^
ObM
^
^
^
...
~^v~^
i
:
Treatment Plant
GW Extraction System (on-property)
Monitoring Wells :
Subtotal Capita! Cost
35 Years, 4% rate, $302^6(Vyr.
/'
Total Cost - On-Property Rec. + Treatment
-
^
Treatment F1«nt ($702,041 + 20%) ~^-^
QW Extraction System (on-pnoperty)
OW&^ptttkwi System (oJHrfbperty)
Monttoring-WeJIs ^^ j
^
**Note>«low2
^
;x^ Subtotal Capital Cost
:o%foradditj&n;
•
*
— -^
^.-^^
$21.600
$2,198.318
$2,219,918
4
$762.841
$230,076
521,600
$1,024,417
$5,641.586
$6,665,983
^
3915.409
$239.976
$356,64U
$21,600
$1, 533,626
^ treatment capacity
^ r
"\
35 Years. 4% rate. ($302,260 +10%) /yr * \, $6,205.723
* Note: Aitow 1 0% for additional maintenance ,
Total Co«t . On-Property Rae. + Treatment: (7,730,348
GWTRCOST.XLS
11/8/96
-------
MAR-18-97 TUE 13:41
P. 03
1 1
Arlington Blendfog Site
Groundwoter Treatment System
Revision of Cost Estimate Provided by BCM
Item Description
Treatment Plant
GioundwaterCoiectfonTank
Dynaaand FlterwHh Caibon
Poflahtno Carbon rater
Compressor
Bag Filter
Effluent Tank
Backwash Tank w/agttation
Pumps
Control Panel
Instrumentation
Control Software
Control PC
Control Software Programmtog
Piping
Ancillary Systems
Electrical
Treatment Briefing (40'x3Cn
Pad Improvement* + Foundation
Quantity
1
1
1
1
1
1
1
6
1
1200
1
/
Units
Ea.
Ea.
ta.
Ea.
Ea.
Ea.
Ea.
Ea.
Ea.
Ea.
Ea.
Ea.
Ea.
Ea.
Ea.
So. Ft
Ea.
Material
Cost
($AmX)
$4,000
$62,000
95,000
$3,500
£2,066
$4,000
15,000
$1,000
$10,000
$70,000
$6.000
$2,500
$15,000
$40,000
$20,000
$28
$20,000
IrstaBaUon
Cost
(SAnt)
$1,000
$20,000
$3,000
$1,000
$1,000
'"5il,Wd
51,000
$300
$5,000
$20,000
$200
$200
$0
$15.000
Total
InstaBaflon
Cost
$5,000
$82,000
$0,ttM
KSOO
!33«r
1 5,000
$6.000
: 1,300
$ 5,000
$90,000
$6200
$2,700
$15.000
$55.000
Treatment Plant Subtotal
$15,000
S28
$20,000
$35,000
$56
$40.000
Ancfflary Systems Subtotal
Subtotal
2% ABowancfl for Contractor Bondinfl and Insurance,
20% Allowance for Enc
3% Allowance for Mob ./Demob.
lineering, legal
Subtotal
and Construction Strvieee
Subtotal
Contingency 20%
Commtccfantng mnd ctutup
"
Estimated Total Treatment Plant Cost
Total
--Cost
$5,000
$82,000
$8,660
$4,500
$3,666
, $5.000
$6.000
$7,800
$15,000
$90,000
$6200
( 2,700
5 5,000
$55.000
$305200
: 35,000
! 67 200
140,000
$142^00
$447,400
$8.948
$13.422
$469,770
$91,954
$563,724
$169,117
$30.000
$7(2,841
GWTRCOSTJCLS
11/8/96
-------
HAR-18-97 TUE 13=42
P. 04
Extraction System (on Property)
Detection Pipe (273" HOPE)
Dfecharae Pip* ft 1/2"/3* HOPE)
WeB Installation
Wen Pump
Valve box
Electrical
Extraction System (off Property)
OoSection Pipe (ZV3" HOPE)
Wecharge Pip« (Increase to 4"/6")
Highway Tumeing
Wen Installation
WeflPump
Valve box
Oectrtcei
.
II '/rm i ^TI TT-f^vr; rrrr^^^^^AMA
wefl installation
750
3230
4
4
4
700
L.F.
LF.
Ea
Ea.
EH.
LF.
20% Allowance for Eng
3000
*~ 3230
90
3
3
3
3000
LF.
L.F.
LF.
Ea.
Ea.
Ea.
LF.
20% Aflowance for Eng
1)
6
J3fi
$30
$5.000
$2,000
$4.000
$10
bvMiina, ktga
$0
, $0
$0
$0
$0
$0
$25
$30
$5,000
: 2,000
J 4,000
- $10
Subtotal
and Construction Sen/ieee
Subtotal
Contingency 20%
rotal Extraction System (On-Property)
$30
$40
$300
$5,000
$2,000
$4,000
$10
$0
$0
$0
$0
$0
$0
$0
$30
$40
$300
$5,000
52,000
$18,750
$96,900
$20,000
$8,000
$16,000
- - $7,000
$166,650
$33,330
$199,980
$39,996
$239,976
$90,000
$129,200
$15,000
$15,000
$6,000
$4,000 i $12,000
$10 | $30,000
Subtotal! $297,200
neering. legal and Construction Services ! $59,440
subtotal
Contingency 20%
Total Extraction system (Off-Property)
Ea.
20% Allowance ft
$2,500
tfEngineerinj
$0
$2,500
Subtotal
and Construction Services
Subtotal
Contingency 20%
Total Monitoring System
5297,200
$59,440
$356,640-
$15,000
$15.000
$3.000
$18,000
$3,600
$21,600
OWTRCOSTJOS
11/6/96
Page 2
-------
MAR-18-97 TUE 13:42. ..
P. 05
I
Arlington Blending Site
Greundwater Treatment System
Projected Annual O*M Costs
Hem
Labor Requirements
System Operator
SampMng Technician -plant
Sampfog Technician - wefc
Analytical
QWohemlottI monitoring
VOC*
SNA's
Pcsflddet
Metals (As)
noroanics
System Monitoring^
VOC^
BNA's
'estidd«
Metals (As)
Romanics
Engineering and Management
Oversight
Enolneering (data + reports)
EPA Oversight
Utilities
Etactrictty
Water
Phone
Supplies
Activated Carbon
Filters and cfcpuval
Maintenance
Quantity
1
1
1
18
18
18
18
18
5
5
5
5
5
1
1
Usage
Rate
8hf/day
Btn/day
8 hi/day
1 sample/yr
1 aample/yr
1 sample/yr
1 aample/yr
1 eample/yr
1 sample/atr
1 sample/qtr
1 sample/qlr
1 «ample/qfr
1 aampfe/qtr
/
/
/
8 hi/day
8hr/dav
Operating
Schedule
365days/yr.
1 day/mo.
4day/yr
Unit
Cost
$2Q/hr
540/hr
$407hr
Subtotal Labor
1 eampfe/yr
1 eampte/yr
1 sample/yr
1 sample/yr
1 sample/yr
4ortrs/yr
4qtrs/yr
4atre/vr
4qtre/yr
4qtrs/yr
$185
!375
$150
$50
$200
Subtotal
$185
$375
Annual
Cost
$58,400
$3,840
$1,280
53,330
! 6.750
$2,700
[ $900
$3,600
$17.280
$3.700
$7,500
$150 i 3.000
$50 $1,000
$200
Subtotal
Subtotal Analytical
48days/yr
45days/yr
$90
$90
Subtotal Engineering and Management,
1
1
1
1
' 1 "
1
1
1/yr
1/yr
1/yr
1/yr
I/day
1/yr
1/yr
$20,000
Subtotal EPA Oversight
1/yr
1/yr
1/yr
$24,000
$2.000
$2,000
Subtotal Utilities
2changes/yr
365(Jays/yr
$15,000
$20
i Subtotal Supplies
1/yr
$50,000
Subtotal Maintenance
T
$4,000
L $19,200
•
$34,560
$32.400
$20,000
$24,000
$2,000
$2,000
•
$30,000
$7,300
$50,000
Total Annual OAM Estimated Cost
Total
Annual Cost
$63,520
4
$36.480
$€6,960
$20,000
*2S,000
$37,300
$50,000
$302,260
GWTRCO3T.XLS
11/8/96
Page 3
-------
»ILJ«V iu a i i 01.
P.OB
O4M (no treatment)
— — . !
Arlington Blending Site
bttrinsle Remediation
Projected Annual O&M Costs
Item
Labor Requirements
Sampling Technician -wefis
Analytical
GIY chemical monitoring
VOC'ft
BNA'c
Pesticides
Metals (As)
InofQ&ntes
Engineering and Management
Oversight
Endneerinfl (data •«• reports)
EPA Oversight
UtilttMS
Bectrfctty
Water
Phone
Maintenance
Stte Makitenanc*
PwUfeing
lyiuwuiy
Quantity
1
18
18
18
18
18
1
1
usage
Rate
8hr/day
1 sample/yr
1 sample/yr
1 sample/yr
1 tamrte/vr
1 sample/yr
8 hi/day
Shrfdav
Operating
Schedule
10day/yr
Su
1 sample/yr
1 sample/yr
1 sample/yr
1 sampie/yr
1 sample/yr
Subtoi
30days/yr
60day&/yr
umt
Cost
$40/hr
btotal Labor
$185
$375
S1SO
$50
$200
al Analytical
$90
$90
Subtotal Engineering and Management
1
1
1
1
1
1
1
1*r
j,
" 1/yr
1/yr
.1/yr
1/yr
1/yr
$20,000
Subtotal EPA Oversight
1/yr
1/yr
1/yr
$1,000
$500
$1.000
Subtotal UtilHte*
1/^r
$10,000
Subtotal Maintenance
4bme8yyr
8times/yr
SuMotal Site
$1,000
$500
Aaintenance
Total Annual GAMES'
Annual
Cost
$3,200
$3,330
$6,750
$2,700
$900
$3,600
$21,600
$43.200
$20,000
$1,000
$500
$1,000
$10,000
$4,000
$4,000
unatedCost
Total
Annual Cost
$3,200
i $17,280
• '
$64,800
$20,000
$2.000
$10,000
'" $«/«o
$117,780
GWTRCOST^CLS
11/8/96
Page 4
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APPENDIX C
i.O
r-o
CD
CD
ON
-------
U05
APPENDIX C
Estimated Mass of PGP Contaminated Soils Remaining After Soil Excavations
-------
APR-21-37 HON 03=39 AH FOCUS ENVIRON- -
FAX NO. 6155318854
b 9
-P;-01/04
OQ37
FAX - Arlington Blending Si
muring ifcfiiiiiiiittf m^
Date; April 18, 1997
To: Derek Matory
Jordan English
Glenn A. Keller
Carter Gray
Tim Eggert
Pete Shingledecker
Leo Diotte
Enrique Huerta
Joe Ricker
From: Paul Sadler
Subject: Contaminant Removal 0
Pages (including cover):
Message:
te
msmmm&ffi2mm8Wm
ID (404) 562-8788
ID (901) 368-7979
D
(901) 576-7810
(404) 951-8910
i
I!. (219)926-7169
LX] (901) 398-4719
r— 1
ata
3
After double checkine and recalculating the contaminant removal
estimates for the Arlington Blending Site 1 found that I had not
included estimates for contaminants left at the railroad. The attached
Tebte 5-4 provides the revised values that will appear in the final
report Also attached is the description of the calculations used to
estimate these removals that win appear in the final report as Aoodx 1.
Paul Sadler
-------
MHOVW..WIU
inm
tn-iu
CD
Table 5-4. Summary of Estimated Contaminant Removals
CNordane
Heptachtor
endrin
HeptacfitorEpoxfde
Pentachlorophenol (d)
Total COC's
1.772
394
355
173
63
2,757
62
16
0.7
85
77
9
1.0
(e)
172
92.3
80.9
96.5
99.0
92.7
91.4
a) Estimated mass of contaminant in soil excavated and thermady treated.
b) Estimated mass of contaminant remaining in sot not excavated. Values assume that remaining soils
ana contaminated at the fnal measured concentration for an additional 2 feet. See Appendix I for
a 1st of assjmptions and an example calculation. Values for mass left in pfe$e at the railroad track
are biased high oy sample SW-022096-I/J04 (see Table 4-6).
c) (Mass Processed) x100/(Mass Processed* Mess Left in Place)
d) Estimates obtained from calculations by Memphis Environmental Center, Inc. (MEC).
e) Mass left in place ca dilated by MEC ferdudas pentachtorophenol left at railroad tracks.
CO
<£>
rn
TO
§
CO
tn
on
CO
oo
en
LT.
\0
C3 ro
<=• 2
CO
-------
APR-21-97 MON 08:40 AM -FOCuS ENVIRON ' • -FAX NO. 6155318854 P. 03/04
. ' »
APPENDIX I b 9
Calculations of Contaminant Removals
R - (MP) (1001
(MP + ML)
MP« (CA) m (F1)
(1,000,000,000)
ML = MU
MU =
(COfSi)
)
CA « Average Contaminant Concentration in Soil Thermally Processed (gg/Ko)
T « Mass of Sop Excavated and Thennaily Processed (41,431 tons)
F1 • Conversion Factor (2.000 IbsAon)
F2 * Conversion Factor (1,000,000.000 jjg/kg)
MU = Mass of Contaminant teft In the Hn Grid (Ib)
Cl = Contaminant Concentration in Final Sample of ith Grid
Si = Mass of Soil in ith Grid (Ib)
VI = Volume of Soil in tth Grid (yd>)
BO * Irvsrtu Bulk Density of Soil (1.6 ton/yd9)
L * Length of ith Grid (ft)
W » Width of ith Grid (ft)
D » Depth of ith Grid (ft)
F3 * Conversion Factor (27 fP/yd*)
-------
'l-y/ HON U«:4J :<•". J-UUUi>. hliViKUN.., ............... MIX NO. blbb^lbdbC ............ -.-.
b 9 0040
Mass of Contaminant Processed
Assumptions:
, 1 The concentration of contaminants in the total mass of soil processed is represented by
the average contaminant concentration from all samples taken during the remedial action.
2 Samples determined to be nondetect for a contaminant are assumed to be contaminated
at the detection limit
Example:
Using the above assumptions for Chlordane the average concentration (CA) of chiordane in
the mass of soil processed is 21,390 ug/kg, then;
MP « (21.390 up/kg) (41.431 tons) (2.000 Ibs/ton) = 1,772 Ibs of chiordane
(1,000,000,000 ug/kg)
Mass of Contaminant Laft in Plaea
Assumptions:
1 Each final sample in excavated grids is representative of a 25 x 25 foot grid.
2 Each final sample from the side walls of the railroad track is representative of a
50 x 20 foot area.
3 Contamination exists in each grid to a depth of 2 feet at the concentration in the final
sample taken in the grid.
Example:
Using the above assumptions in Grid M10 where the final chiordane concentration was
measured to be 8,360 ug/kg, the mass of chiordane left in place at Grid M10 is.
ML10 * (8.360 ua/koUS 10 Ib)
1,000,000,000 ug/kg
S10 = (V10ytf) (1.6 ton/yd*) (2,000 Ibs/ton)
V10 = (2SftH25ft)(2m » 46.3 yd"
(27ftVycr)
S10 = (40.3 yd») (1.6 ton/yd") (2,000 Ib/ton) = 148.148 Ib
ML10 = (8.360 uq/kg>M48. 148 ib) - 1.2 Ib of chiordane
(1.000.000.000 ug/Jcn)
Continuing this procect for each grid and the coile loft at the reilroed track end summing generates
an estimate of the total mass of chiordane left in place of.
ML = 62 (in excavations) * 85 (at the railroad) = 147 Ib
R « M.7721 MOO) « 92.3%
(1,7/2 V 147)
See Table 5-4 in the report for a summary of the results for all organic contaminants of concern.
-------
APPENDIX D
o
o
o\
-------
b 9 0042
APPENDIX D
Local Ordinances Regarding Well Installation and Water Withdrawal
-------
December 27,1996
In addition, the results are based the highest average groundwater concentration detected at the Site for
each contaminant as presented in EPA's mndrfng study (EPA's Review of "Groundwater Modeling
Effort to Evaluate pgnifdfol Alternatives fix- Contaminated Groundwater at the Arlington Blending and
Packaging Site," October 17, 1996). 'These concentrations are likely never to discharge to the river.
Much lower concentrations of the contaminants of concern wffl most likely discharge to the
Loosahatdne River. It is anticipated that contaminants wffl degrade during migration in the suraoal
aquifer due to a number of transport phenomena 5W?h as biodegradation, dispersion, and dilution due to
recharge. Off-property groundwater analytical results are consistent with this theory. For example, the
highest off-property groundwater PCP concentration to date is 325 jt%j\ in off-property weD AB-9D.
In addition, a plume discharge width of 400 feet is conservative. Bcsed on groundwater analytical data,
the plume discharge width at the river may be over a river length on the order of tens of feet as opposed
to hundreds of feet In any event, the highest average groundwater concentration discharging over the
entire plume discharge width is very unGkeiy.
Table 1 - The Results of the Surface Water Daation Calculation
CtfrWuund
PCP
1.1-DCE
^JCOZHSC
AvUGUDD^B
•yr^^^^yt^ffjfujtt
mg/I
L106
0.0273
0.0504
Dilation
falcnhtion
Remits
mgfl c.
0.0005
0.00001
0.00002 .
AjDflul2iD
Rfi^^PC^K^tOR
Regulatuy
Limit (a)
mgfl
0.007S
0.0005
0.0012
Aquatic
Regulatory
Limit (b)
mg/I
0.013
0.00057
0.012
(a) - Human Recreatiorf regulatory limits based on TDEOs Division of Water Pollution Control1
Criteria
(b) - Aquatic regulatory limits based on TDECs Division of Water Pollution Control Criteria
(Division of Water PoDution Control Regulations, Chapter 1200-4-3 - General Water
Quality Criteria).
-------
9 0053
Memo (Continued)
February 14, 1997
Page 2
(2) Surficial aquifer groundwater discharge to the Loosahatchie River.
As noted on page 6 in the Groundwater Modeling Report, surficial aquifer groundwater flows
north-northwest across the Site and discharges to the Loosahatchie River. This information was
based on site-specific groundwater head measurements, general hydrogeology of the area, and the
EPA's Final Remedial Investigation Report (Final Remedial Investigation Report: - Volume I RI
Report Text, Arlington Blending and Packaging Site, November 1990). Specifically, Section 5.2
- Surface Water/Sediment Contaminant Fate and Transport and Section 5.2.1 - Surface
Water/Sediment Contamination from Ground-water Discharge (page 134) of^the EPA's 1990
report discuss discharge of the surficial aquifer groundwater to the Loosahatchie^tiver.
*
Although Loosahatchie River flow measurements are not available upstream and downstream of
the Site to quantify the rate of groundwater discharge to the river near the Site, it is believed that
all surficial aquifer groundwater discharges to the river year-round. This information is consistent
with your conversation on Friday February 7, 1997 with the USGS (Mr. Larry B. Thomas of the
USGS Water Resources Division, Memphis, TN). The USGS considers the Loosahatchie River
near the Site to be a gaining stream year-round. Furthermore, they consider the River's base flow
to be fully supported by discharge from shallow aquifers, including the surficial aquifer at the Site.
Attachments
i:\*big\modfiow\b«lch\f>cpnx3no.
-------
C29.J WATZH
W«tw Control B^rf Ch. 4S7. Prt 194»
Water Quality Control Ou 167. Pn. IflTl
PRIVATE ACTS, 1949. CHAPTER 497.
AN ACT to authorize the County of Shelby in connection
and in conjunction with the City of Memphis to es-
tablish a Board to be called the Memphis and Shelby
County Board of Water Control, with powers to rsgtt*
lata, Emit and prohibit :he drflUnor of wells fa Mcmphi*
and Shelby County; to regulate £he exploitation and
consumption of artesian water unosr the land in said
City and County; otherwise defining the powers and
duties of said Board; defining the qualifications yf
the members; fixing their terms of office, and their
procedure*
[29*1] SECTION 1. Be it enacted by the General Assembhr
of the State of Tennessee, That whereas the water supply of-
the City of Memphis, Shelby County, Tennessee, is obtained
from artesian wofls operated by the Lfcht, Gas and Watetf
Division of the City of Memphis, said water supply being for-
nished by the said Light, Gas and Water Division of the City
of Memphis not only to citizens of the City of Memphis, but
to the citizens of certain portions of Shelby County outsitto
of the said CSty of Memphis; ami
WagfcEAS. the -water supply of other citizens in Shelby
Coonty.'outside the City of Memphis, is obtained byttfaem by
means of private artesian weQs; and
WHEREAS, many large industries in the City of Memphis
and its environs operate private weHs. which contribute to th»
exhanatioa of the said subterranean water supply, year by
year lowering th« lev«I of the amid subtcrrueaa waters, and1
tending to endanger the pore water supply available to User
citizens of the City of Memphis and Shelby County; and ' i
WHEXEAS, the maintenance of a plent^ul subterranean
water supply for the thickly populated -ctan-area in; and?
1979
-------
RULES AMD REGULATIONS OF HELLS
IN
SHELBY COUNTY
PURSUANT TO THE AUTHORITY GIVEN IN THE ORDINANCES OF SHELBY COUNTY
AND THE MUNICIPALITIES THEREIN WHICH ESTABLISHED THE GROUND WATER
QUALITY CONTROL BOARD FOR SHELBY COUNTY; TO ESTABLISH INSPECTION
AND PERMIT FEES; TO CONTROL AND REGULATE THE LOCATION,
CONSTRUCTION, AND MODIFICATION OF ALL TYPES OF WELLS IN SHELBY
COUNTY; AND TO PROVIDE PENALTIES FOR THE VIOLATION THEREOF.
SECTION 1 — GENERAL PROVISIONS
1.01 — Statutory Authority
The Ground Water Quality Control Board for Shelby
County establishes and adopts the following
regulations in accordance with the authority
granted by the ordinances of Shelby County and the
municipalities therein which established the Ground-
Water Quality Control Board for Shelby County •
*
1.02 — Scope and Applicability
A. Minimum requirements are hereby prescribed in these -
Rules and Regulations governing the location,
design, installation, / use, disinfectation,
modification, repair and abandonment of water wells
and associated pumping equipment, or any other type
of well. No person shall conduct any activity
contrary to the provisions of these regulations,
and all such activities which are contracted foa?
shall be carried out only by those persons having a
valid Tennessee License for Water Well Drillers1,,
* and Pump Installers and/or those engineers oar
geologists registered in the State of Tennessee.
These regulations supersede all other well
construction regulations.
B. These regulations apply to well construction
activities from the initial penetration 02?
excavation of the ground, through development,
modification, equipment instillation, repair and)
disinfection. Set up of construction equipmentl
before actual penetration or excavation is noH
considered part of the construction.
C. The regulations apply to the construction
activities of any and all types of wells.
-------
Pages 2 -8 intentionally left out
-------
3.56 -- Well Loos: A record of geologic formations
penetrated in drilling a water well, monitoring,
recovery, dewatering, observation or any other type
of well; or any boring into the subsurface thirty
(30) feet or deeper.
Section 4 GENERAL^ REQUIREMENTS AND PROCEDURES
4.01 -- Applications
A. Any person requesting the installation,
modification, repair, or abandonment of a water
well or any other type well shall make application
to the Department.
B. All applications requesting new well installation
or the modification of an existing well shall be
accompanied by a plot plan showing the location of
all underground utilities within fifty (50) feet of
the proposed well; grade elevations in relation to
adjoining areas and drainage patterns of the area;
location of the residence, business, etc.;
locations of septic tanks and field lines when
applicable; other existing and proposed buildings.
and structures; any wat/er service lines that may
exist on the premises; afoy drainage ditches, lakes,
ponds, streams, etc., that may exist at the
premise; any roads or dedicated right-of-ways or
easements; and any other pertinent information
deemed necessary by the Department. The
application shall also include a sketch of hoy the
well is to be constructed.
V C. A water well cannot be sited or placed in service
within a half-mile of the designated boundaries-of
a listed .. federal or... State.-Super fund site or
Resource Conservation iandisRecovery Act corrective
action- site, unless the well owner can make a
demonstration that the well will not enhance the
movement of contaminated ^groundwater or materials
into the shallow or deep aquifer.
D. An application may be obtained from the Department,
and if approved, such application shall be in force
and in effect for ninety (90) days from the date of
its issuance. If work has not commenced within
ninety (90) days of issuance, an extension may be
granted by the Department upon request by the
applicant.
E. A processing fee shall be submitted with all
-------
Pages 10-12 intentionally left out
-------
applicable laws and regulations.
D. It shall be the well driller's duty to inform
persons requesting the services of his company, to
construct, repair, alter, modify, or to perform any
other service related to a well of the requirements
of these Rules and Regulations.
E. The well driller shall be held liable for any type
of well work initiated prior to the Department:
issuing a written permit.
" F. It shall be the duty of the well driller to notify
the Department when construction on a well is to
begin and when the work is completed so that proper
inspections can be made during and after
construction, and for the purpose of collecting;
samples from production wells.
G. The well driller shall notify the Department when
repair or modification work, as directed within
these Rules and Regulations, is done on a well.
H. Within thirty (30) days after a well has been
constructed or modified, the well driller shall
submit a report of constriction (well log) to the
Department on such forms as are prescribed or which
may be furnished by the Department.
I. The well driller shall notify the Department prior
to beginning abandonment procedures on a well.
Section 5 — WELL CONSTRUCTlfaN
5.01 — General
%
A. All wells shall be constructed in a manner that
will guard against waste and contamination of the
groundwater aquifers underlying Memphis and Shelby
• County- No person shall construct, repair, modify,
or abandon or cause to be constructed, repaired,
modified, or abandoned any well contrary to the
provisions of these Rules and Regulations.
5.02 — Siting Criteria
A proposed well location shall satisfy the
following Tnin<™mi horizontal separation distance
requirements:
1. Fifty (50) feet from a property line, to allow
access to the well without encroaching on
adjoining properties; to provide adequate
13
-------
distance from field lines and other sources of
contamination that may exist or may be planned
on adjacent properties; and, to reduce the
potential for interfering with other wells
drilled on other properties.
2. Twenty-five (25) feet from a road or dedicated
right-of-way or easement.
3. Fifteen (15) feet from a building foundation
for the purpose of protecting the well from a
foundation of soil treated to control pests,
insects, or vermin.
4. One hundred (100) feet from any subsurface
sewage disposal system such as a septic tank
and/or field lines.
5. One hundred (100) feet from any identifiable
sources of contamination such as but not
limited to disposal fields, seepage pits,
manure piles, barns, underground fuel tanks,
etc.
6. Fifty (50) feet from any storm drain or _
sanitary sewer that flows by gravity.
7. One hundred (100) feet from any sewage force
main.
8. Fifty (5Q) feet from any drainage canal,
ditch, stream, lake, or similar body of water.
9. Fifteen (15) feet from power lines and
V underground cables for electrical power.
10. Twenty-five (25) feet from natural gas lines
11. Twenty-five (25) feet from any water main as
defined by the utility owner.
B. The well site shall not be subject to flooding and
shall be at least" two (2; feet above; the 100-year
recurrence flccd level for the area! If necessary,
tfie area shall be filled with material approved :by
the Department, properly graded *an
-------
D. All parcels of land requiring a well for a source
of potable water shall be self-supporting in that
sharing a water supply shall not be allowed. A
water line shall not cross property boundaries for
the purpose of providing potable water to a premise
on a permanent basis.
E. A well cannot be sited or placed in service within
a half-mile of the designated boundaries - of a
listed-federal or State Superfund site or Resource-
Conservation and Recovery Act corrective action
site, unless the well owner can make a
demonstration that the well will not enhance the
movement of contaminated groundwater or materials
into the shallow or deep aquifer.
5.03 — Sanitary Protection of Wells
A. All water used in the construction of a well shall
be from an approved potable water supply. Water
obtained from lakes, ponds, streams,, and other such
surface water sources is not approved and shall not
be used in the well construction process. *
B. It shall be the responsibility of the well driller
to protect the opening made in drilling the well "
against any foreign material or any other type of
contamination from entering the opening.
C. In the event a well becomes contaminated or
obstructed, the/well driller shall take whatever
measures necessary to clear the well of
contamination or obstruction. Should he decide to
abandon the well for any reason, the well shall be
filled in a manner prescribed by Section 9 of these
* Rules and Regulations.
D. Whenever construction stops before the well is
grouted and pumping equipment is installed, the
open annular space shall be covered and the well
casing capped. The cap shall be either threaded
onto the casing secured by a friction type device
which locks onto the casing, welded, or secured by
such other device or method as may be approved by
the Department. It shall be the responsibility of
the owner to maintain the integrity of the
protective device placed on the well opening by the
well driller.
E. A well shall be drilled to a size that will permit
the outer casing to be surrounded by a water tight
seal a minimum of two (2) inches thick. All wells
15
-------
Pages 16 -30 intentionally left out
-------
systems. The Department: shall require--.the
reuse of water for cooling through the use of
cooling towers, evaporative condensers, or
some other such device or method approved by
the applicable code.
D. All residential, commercial and industrial
heat pump systems, shall be a horizontal.
closed loop system with no discharge. The
design of "such heat pump systems, shall be
approved by the applicable code, and the owner
shall have a valid mechanical permit.
E. Non-aqueous heat pump systems shall be
prohibited.
Section 12 — AVAILABILITY OF PUBLIC WATER
12.01 — Public Water Available To A Premise
A. Public water shall be deemed available to a
premise other than a subdivision when 4it is
located within three hundred (300) feet of
said premise.
B. When proposed subdivisions are comprised of
premises used or intended for human habitation
or other establishments where a water supply
is or may be used for human consumption and
where such, subdivision is. located within one
quarter / (1/4) mile of public water
distribution facilities in existence i^* a
dedicated right-of-way, the developer of such
subdivision shall extend the water supply
mains and connect all lots thereto.
C. The distance between an existing water main in
a dedicated right-of-way and a premise or
proposed subdivision shall be measured by an
actual or imaginary straight line upon the
ground or in the air between the point within
the premise or subdivision nearest to the
existing water main in dedicated right-of-way
and the point where the existing water main in
a dedicated right-of-way comes into closest
proximity with the premise or proposed
subdivision.
D. The connection to a public water supply shall
be made in accordance with the requirements of
all applicable rules and regulations of any
31
-------
county/ state, or municipal agency having
jurisdiction thereof.
E. The provisions of this section relate to
single-family, multi-family, commercial and
industrial-zoned lots and are applicable to new
subdivisions , and existing subdivisions which
are unplatted or unrecorded.
?. The provisions of this section shall not apply
when a utility cannot provide a public water
distribution system due to the utility's
franchise limitation or the inability or
unwillingness of a city to extend its public
water distribution system.
G. The construction of a well shall not be
permitted at a premise where public water is
available and which said water supply has a
yield and pump capacity to provide the
quantity of water which the user has stated is
necessary for purposes for which the water is
intended to be used unless otherwise provided >v
by this code. ' ' •
H. When a public water /system (pws) is available
to a residential premise the potable water
shall be obtained from the public water
system. A well may be approved by the
Department for construction on a residential
premise where public water is available under
the following circumstances:
1. For filling a lake, providing such lake,
pond or similar continuous body of water
is not less than one f 11 acre in size,
with the -otal parcel of land being no
less than four (41 acres in size.
2. For irrigation, provided such parcel of
land is no less than four (41 acres, in
size.
3. For watering livestock, provided the
parcel of land to be served is no less
than four ( 4 ) acres in size.
I. A well may be approved by the Department for
construction on a commercial and/or
industrially zoned premise where public water
is available, provided the owner demonstrates
to the Department that no reasonable
32
-------
alternative water supply to the proposed well
exists. The potable water supply shall be
obtained from the public water system.
J. The construction of a water well or any other
type of well regardless of use on a lot or
premise less Than four (4) acres in size
utilizing a septic tank system for sewage
disposal, shall not be permitted by the
Department.
12.02 -- Pqfolic Water Not Available To A Praise
A. Public water shall be deemed not available to
a premise if it is located a distance greater
than three hundred (300) feet of said premise.
B. Public water may be deemed not available to a
premise if the topography and land surface
features are such that they economically or
structurally prevent connecting to public
water.
12.03 — Auxiliary Intake
No auxiliary intake for/ a potable water supply'
shall be made or permitted unless the source and
use of the auxiliary supply and the location and
arrangement of the intake are approved by the
Department in writing.
Section 13 — INJECTION WELJ.S
No injection wells of any type shall be allowed in
Memphis and Shelby County for the injection of surface or
groundwater, or chemically or thermally altered water, or
any other fluids into the underground formations. No
well constructed shall be used for recharge, injection,
or disposal purposes. Injection wells for the purpose of
improving groundwater quality may be considered under
Section 14.02, but approval of these wells will not
release the appellant of any applicable requirements
under state or federal lav for the remediation of
contaminated groundwater or materials at the site.
Section 14 — VARIANCES
14.01 — Sxistinc Wells
Wells in existence on the effective date of this Act
shall be required to conform to the provisions of these
Rules and Regulations, or any rules or regulations
33
-------
APPENDIX E
r-o
•~n
O
CD
ON
-O
-------
b 9 0354
APPENDIX E
Surface Water Dilution of COC's in the Loosahatchie River
-------
5 9 0055
duDtdctf
OnePfymatOkMi
PfymtHOk Meeting. P/to9462
FAX (6iq S34-S236
December 27, 1996
To: Memphis Environmental Center (Enrique Huerta, Norm Kennd)
Subject: Surface Water Dilution in the Loosahatchie River
The groundwater flow direction in the surficial aquifer at the Arlington Blending and Packaging Site
(Site) is north-northwest. Surficial aquifer groundwater flowing from the She win discharge to the
Loosahatchie River and will be diluted with river water. Smith Technology used the following equation
to determine the concentration of each contaminant of concern after dilution in the Loosahaichie River
Q \
where 7*. <$•
c - concentration of contaminant in the river water (M / V)
c = concentration of contaminant in groundwater discharge (M / V)
9 *
' 2
d = groundwater discharge to the river from the Site per unit length of river (L / T)
x = width of the groundwater plume discharging to the river (L) *
Q= flow in the river (I?/T) |
e
This equation calculates the concentration of a given contaminant in a river at a specified distance
downstream from the point where the contaminated groundwater discharge begins to enter the river.
The equadon assumes that a ground v.ater plu.ae discharges into a river along the entire specified river
length. The equation also assumes steady-state conditions. That is, groundwater discharge,
contaminant concentrations in the groundwater, and surface water flow do not change over time.
*n
-------
00
December 27,1996
Page 2
2 d » 3.02E-06 feet2/second « (Darcy velocity) (depth of aquifer) - (0.26 feet/day) (30
feet).
3. x - 400 feet (Le., estimate of maximum width of plume discharging along the
Loosahatchie River).
4. Q - 73.6 feet3/second = Loosahatchie River low flow based on the 3 day minimum,
20 day recurrence interval flow measurement at the bridge on U.S. Highway 70 and 79
near the Site (Source: Flow Duration and Low Flows of Tennessee Streams through
1992, USGS Water Resources Report 95-4293,1996).
The results of the above surface water dilution calculation are presented in Table 1. The calculation
results indicate that each contaminant will be diluted below its respective Regulatory limit in the
Loosahatchie River when the highest average groundwater concentration at the Site for eacb
contaminant is used as input. Regulatory limits were obtained from TDECs Division of Water
Pollution Control. Benzene and 1,1-DCE are diluted by 3 orders of magnitude, while PCP is diluted by
4 orders of magnitude. Thus, PCP, 1,1-DCE, and Benzene will not pose an environmental risk in the
Loosahatchie River.
The calculation results are consistent with results from actual Loosahatchie River samples taken to
date, which indicate that the river has not been measurably impacted by Site groundwater. These
results indicate that either the contaminants of concern are not present in groundwater discharging to
the river or the contaminant levels in discharging groundwater are attenuated by surface water mixing in
the Loosahatchie River. Surface water sample results are presented in Appendix F of the ground v-atef
modeling report (Groundwater Modeling Effort to Evaluate Remedial Alternatives for Contaminated
Groundwater at the Arlington Blending and Packaging Site, August 15, 1996).
Note that the calculation results are conservative for the following reasons. The results are based on
dilution using the Loosahatchie River low flow (i.e., the 3 day minimum, 20 day recurrence interval
flow measurement at the bridge on U.S. Highway 70 and 79 near the Site). The discharge in the
Loosahatchie River is typically much greater - 116 feet^/second equaled or exceeded at least 50 % of
the time. Yet, the above calculations assume that the Loosahatchie River is always 73.6 feet3/second.
The 3 day minimum, 2C year recurrence interval flow was used for calculating impact against both
TDECs Human Recreation and Aquatic water quality criteria. The 30 day minimum, 2 yeW recurrence
interval, which TDECs Division of Water Pollution Control Regalations state should D^ used for
calculating impact against Human Recreation water quality standards, is 80.3 feetVsecond.
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APPENDIX F
ON
!~0
CD
O
O\
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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REGION 4
ATLANTA FEDERAL CENTER
100 ALABAMA STREET. S.W.
ATLANTA. GEORGIA 30303-3104
October 10, 1996
4WD-OTS
MEMORANDUM
SUBJECT: Ground-Water Modeling, Arlington Blending Site,
Arlington, Tennessee
FROM: William N. O'Steen, Environmental Scientist
Office of Technical Services
Waste Management Division
THROUGH: Elmer Akin, Chief /
Office of Technical Services Xj
Waste Management Division /.
TO: Derek Matory, Remedial Project Manager
North Site Management Branch, Kentucky Tennessee
Section
This memorandum responds to your request for a review of the
report titled "Groundwater Modeling Effort to Evaluate Remedial
Alternatives for Contaminated Groundwater, Arlington Blending and
Packaging Site, Arlington, Tennessee". Within this memorandum,
this document is identified'as "the report". For your
convenience, comments are referenced to specific pages or
sections of the report, as applicable.
Accompanying my review of the report is an independent modeling
assessment of the remedial alternatives modeled by the PRPs'
contractor, as well as an evaluation of additional remedial
alternatives which may be more efficacious in a ground-water
remedial action. Because the goal of the EPA and the state
environmental regulatory agency is to make an informed decision
regarding the appropriateness of an active ground-water remedial
action at this site, it may be most advantageous for you to use
this memorandum and the draft report as the support documents for
such a decision, rather than to request that the PRPs provide a
revised modeling report for our further consideration.
To assist you in your understanding of my report review and the
independent assessment I have performed, a summary and
conclusions section is included at the beginning of the body of
this memorandum.
If you have any questions regarding this memorandum, or require
additional technical assistance, please contact me at x28645.
R*cycl«d/R«cyclabU • Printed with Vegetable Ol Based Inks on 100% Recyded Paper (4O% Postoonsumer)
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-2-
Summary and Conclusions
o Based on my confirmatory modeling of the ground-water flow in
the vicinity of Arlington Blending, I conclude that the PRPs'
contractor's Modflow modeling analysis of the Arlington Blending
vicinity is a fairly good approximation of ground-water flow.
Some adjustments could, however be made which would improve the
match between observed and model-predicted ground-water
elevations in the upper sand aquifer.
o i concur that the leakage of water from the upper sand aquifer
to the Memphis sand aquifer (or vice versa) is inconsequential in
the area of contaminated upper sand aquifer ground water, under
ambient conditions. Pumping of a water-supply well in the
Memphis sand in the vicinity of the upper sand aquifer ground-
water contamination is unlikely to induce measurable, if any,
downward migration of ground-water contaminants.
i
o The approach used by the PRPs' contractor to estimate ground-
water remedial time frames is a valid method for determining
relative time frames for different remedial options; it may
generate only very approximate values for absolute remedial time
frames. For this application, the modeling approach to estimate
remedial time frames is only valid if significant contaminant
mass is restricted to the ground water and aquifer materials in
the aquifer being modeled. /,
o in addition to the six remedial options considered by the PRPs'
contractor, I modeled five additional remedial options. The
modeling results obtained by myself and the PRPs contractor are
roughly the same, although my modeling indicated lower pore
volume flush times for the six alternatives the PRPs' contractor
modeled. Some of the additional off-property remedial
alternatives I considered-indicate that shorter off-property pore
volume flush times are attainable than for any of the modeling
simulations run the PRPs' contractor.
o i disagree with the PRPs' contractor's approach of using the
maximum observed ground-water concentrations to determine the
number of pore volume flushes needed to remove ground-water
contaminants under different model scenarios. Instead, I used
the maximum average of detects from any one well in the upper
sand aquifer to predict the number of pore volume flushes
required.
o Primarily because of the difference in specifying the initial
concentrations of ground-water contaminants, I have determined
that the. number of pore volume flushes needed to remove each one
of the contaminants of concern is different than the values
determined by the PRPs' contractor. The difference is most
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-3-
signifleant for chlordane and pentachlorophenol for the ori-
property remedial evaluations. The estimates are comparable of
the necessary number of off-property pore volume flushes.
o The PRPs' contractor calculated aquifer cleanup times with the
assumption of no contaminant biodegradation, and with the
assumption of contaminant biodegradation at a rate equal to the
maximum literature-reported half life. The aquifer cleanup times
calculated assuming such biodegradation are illustrative of what
might be expected under the best of conditions, but may not be
realistic with respect to the Arlington Blending site. Although
there are some ground-water contaminants at the Arlington
Blending site which are degradation products of pesticide
compounds, these substances may also be product impurities which
were coincidental contaminants at the facility. Among other
concerns about biodegradation, lengthy plumes of contaminants
such as 1,1-DCE and benzene imply that limited or no ground-water
biodegradation of contaminants is occurring. Thus, this process
should be considered with caution.
o I have tabulated aquifer cleanup times for all contaminants of
concern, for conditions where there is no biodegradation
considered, and for conditions with biodegradation. I have then
compared these results to results obtained by the PRPs'
contractor, and have analyzed the differences. The results of
this analysis are enumerate^ as follows:
1. My analysis predicts shorter remedial time frames for all
modeled scenarios, compared to the results obtained by the PRPs'
contractor. Such, shorter time frames range from substantial
differences to insignificant differences, depending on the
contaminant and scenario modeled.
2. With biodegradation at a rate predicted by the maximum
literature-reported half life, there is little advantage obtained
by an active remedial action, versus the intrinsic degradation
alternative. That is, the major process removing contaminants
from the aquifer is biodegradation, not physical removal by
recovery wells or natural ground-water discharge.
3. Assuming there is either no biodegradation, or biodegradation
occurs at a substantially slower rate than that predicted by the
maximum literature-reported half life for a contaminant, my
modeling indicates there will be a significant difference in
remedial time frames for one or more active remedial
alternatives, compared to the intrinsic remedial alternative. Of
particular significance is the off-property remediation of
pentachlorophenol (potential active remedial time frame of
between 40 and 50 years with no biodegradation, versus 138 years ~
for intrinsic remediation) j and on-property remediation of endrin
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-4-
(potential active remedial tine of approximately 30 years/ versus
approximately 70 years for intrinsic remediation).
4. Regardless of the modeled scenario, my analysis indicates that
an active remedial action to address on-property chlordane
ground-water contamination may be unwarranted. With significant
biodegradation, intrinsic remediation of chlordane is virtually
as effective as any active remedial action. In the absence of
biodegradation, remedial time frames for chlordane are predicted
to be approximately 100 years or more under the most efficient
on-property remedial alternative, which is in the realm of
•technical impracticability". Regardless of the need for active
remedial action to address the problem, monitoring of the on-
property chlordane ground-water contamination is needed.
5. Because of localized concentrations only marginally above the
ground-water target concentration, active remedial action* to
address the on-property heptachlor epoxlde contamination is
probably not needed.
t
6. A primary reason for the most significant discrepancies
between my predicted remedial time frames and the PRPs'
contractor's values relates to the predictions of the fate of the
low mobility pesticides (chlordane, heptachlor epoxlde and
endrin) in areas downgradlent of the property. Because of their
low mobility (sorptive properties) and limited contaminant mass
below the water table, I believe these compounds will migrate
limited distances (if at all) downgradlent of the Arlington
Blending property before being diluted or partitioned to soil,
such that dissolved concentrations are below levels of concern.
The PRPs' contractor's analysis assumed that pore volume flushing
of the entire upper sand aquifer downgradlent of the property
would be necessary before ground-water remedial goals would be
attained.
Section 2 Ground-Water Flow Model
I concur with the use of the Modf low model to evaluate the
ground-water flow patterns at and downgradient of the Arlington
Blending site. I have independently run Modf low as a check on
the PRPs' contractor's work. For this effort, I have generally
followed the PRPs' contractor's conceptual hydrogeologic model,
and have relied on the site-specific data presented in the
report. I considered the same model domain and used the same
grid line spacings and numbers as did the PRPs' contractor. I
considered the Memphis sand in the same way as did the PRPs'
contractor (a valid approach, since one is comparing remedial
alternatives in the more localized flow system of the upper sand ~
aquifer) . I also considered the Loosahatchie River canal as a
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-5-
constant head boundary (river boundary cells). I have not
included the detailed model input and output with this
memorandum, as it is generally similar to the information
provided in the report.
My modeling work confirms that the PRPs' contractor's ground-
water flow model is basically correct, although there are some
minor adjustments which could be made to improve the correlation
of measured versus model-projected water levels for the steady-
state condition. For example, conceptually, one would consider
that ground-water recharge in the immediate vicinity of the
Arlington Blending property would be slightly less than
elsewhere, because of the presence of additional paved surfaces,
buildings and the like, in comparison to the primarily
agricultural areas to the north and south. Likewise, ground-
water recharge in the immediate vicinity of the Loosahatchie
River canal, is negligible, and some degree of ground-water
evapotranspiration is probably occurring near th? stream.
Additionally, modification of the transmissivity', of the unit 2
aquifer (as defined in report Table 1) on a localized basis would
improve the match between observed and model-predicted water
levels somewhat. However, the PRPs' contractor's selected
calibrated site model from Table 3, (Run C; see bottom of report
page 13) is fairly close to the best fit results I have obtained,
using slightly modified transmissivity and recharge values in
localized parts of the model domain. A comparison of results is
presented in Table 1. Figure 1 of this memorandum shows the
hydraulic head distribution in the upper sand for the calibrated
flow model I ran.
i
Table 1 Comparison of the Report Calibrated Model Results
with My Calibrated Model Results
Report Calibrated Model:
Unit 2 aquifer transmissivity: 2000 fta/d
Unit 2 recharge: 0.00067 ft/d
reported correlation coefficient: 0.975
RMS error (see report Figure 8): 0.872
i
My calibrated model;
Unit 2 aquifer transmissivity: rows 30 through 35, columns 6
through 47, 1500 fta/d; rows 25 through 29, columns 6 through 47, 1800
ftVd; elsewhere, 2000 fta/d
Unit 2 recharge; rows 41 through 46, columns 6 through 47, 0.0004566
ft/d; river (boundary) cells + 3 rows north and south of each river cell
0 ft/d; elsewhere 0.000685 ft/d.
calculated correlation coefficient: 0.987
RMS error (Figure 2 of this memorandum) = 0.797.
-------
Figure 1
<5OOO
7200
3000
E2PA — Atlanta. GA
frojoofct ArlirMEton. upper aouad
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Modeller: B.
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Vtaued MODITLOW ViS-OOu (o) 1OOC
Waterloo Ryriroeoolo
NO 61 NRi 63 NLc
Currant.
-------
Figure 2
ct
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CM
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S8'
10
M
V>
Periodr 1
Step:' 1
2t8 250 252 . 254 256 258 260 262
Observed headsCftJ
Mean error: -0.09170227 Mean tibs. err: 0.6211686 RMS error: 0.7972055
EPA — AUax&t*. GA
Frojoot: ArlirkctoQ- BlenxUnc
Poaorijptlon; Steady St«ta Rvya.
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Vlavud MODFTJOW v.aoO, (o) 1G9S
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NO Ca NB: 63 NL« 4-
Cursnazat.
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-6-
I have also run a mass balance analysis and concur with the
conclusion presented in Section 2.6, page 14, that leakage of
water from the Memphis sand aquifer into the upper sand aquifer
(or vice versa) is inconsequential in the area of concern under
ambient conditions.
Section 3 Evaluation of Remedial Alternatives
i
Section 3 of the report first presents the approach used to
estimate time frames for various remedial alternatives which are
considered for the Arlington Blending ground-water remedial
action. I concur with the approach that was selected for this
evaluation (as per a copy of my memorandum to you dated January
29, 1996, presented in Appendix C). However, I do note for the
record that the selected approach should be considered to give
rough estimates of ground-water remedial time frames and may
therefore best be considered in relative rather than absolute
terms. Also, for ground water, the method used to calculate
remedial time frames assumes that the source of contamination has
been effectively removed, so that essentially all the contaminant
mass is in the ground water and aquifer materials of the upper
sand aquifer. It is my understanding that this condition has
been met at this site.
Section 3.1 Modeling
Section 3.1 of the report presents the results of modeling (using
Modflow/Modpath) of six remedial alternatives. I have run these
six simulations, as well as five additional remedial design
configurations, for further comparison to the intrinsic
remediation conditions. For the intrinsic remediation condition,
X used the calibrated flow model I have developed (as described
on the previous page), in place of the calibrated model developed
by the PRPs' contractor.
For the eleven remedial alternative simulations I ran, the
following conditions apply:
simulations 1 through 6 are the same as simulations 1 through 6
as defined in the report Table 4.
simulation 7 is the same as simulation 2, but with three
additional off-site recovery wells: row 33, col. 22, Q = -3850.3
ft3/d; row 23, col. 22, Q «= -3850.3 ft3/d; row 12, col. 20, Q «=
-3850.3 ft3/d.
simulation 8 is the same as simulation 2 but with eight
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-7-
additional off -site recovery wells: row 31, cols. 19-22, Q « -
2887.7 ft3/d; row 14, cols. 19-22, Q - -2887.7 £t*/d.
simulation 9 is the same as simulation 2 but with four recharge
wells: row 39, cols. 16,19,21 and 24, Q/well - 2887.7 ft'/d (same
as simulation 6, but different location -of recharge wells.
simulation 10 is like simulation 2 but with 5 recharge wells: row
38, cols. 16, 18, 20, 22, 24, Q/recharge well - 2310.2 ft3/d.
i • .
simulation 11 is like simulation 10 but with one additional well
at row 13, col. 20, Q - -3850.3
For each remedial alternative, I have calculated the time
required to remove 1 pore volume in a manner similar to the PRPs'
contractor. Because of some computer hardware limitations, my
approach was slightly different (forward Modpach particle"*
tracking, versus backward tracking which is the preferred
technique) . My analysis yielded results which . are rougher
estimates, in terms of predicting pore volume flush times which
would be estimated by each model simulation. However, I believe
that my baseline calibrated model is probably more accurate that
the PRPs' contractor's, which should yield somewhat better
estimates of pore volume flush times. I have considered the " on-
property" condition to represent the area within the capture zone
for on- property recovery wells, with the exception of the
intrinsic flow condition, where on-property was considered to
extend to the vicinity of monitoring wells just across U.S.
Highway 70 from the property. For the intrinsic condition, the
time for l pore volume flush of on-property ground water was the
time required for a simulated particle to move from the
upgradient Arlington Blending property line to the downgradient
margin of the area defined as on-property.
The results of my modeling of times required for 1 pore volume
flush are presented in Table 2 of this memorandum. Appendix A
shows figures' prepared for each of the 11 model simulatior.s,
considering both on-property and off -property conditions'.
Discussion of Results
t
Table 2 of this memorandum can be compared to Table 5 of the
report. Both my modeling and the modeling by the PRPs'
contractor indicates that certain configurations of recovery
wells will increase the time for one pore volume flush to occur
in areas downgradient of the Arlington Blending property. My
modeling indicates shorter time periods for a pore volume flush
than predicted by the PRPs' contractor, for all of the six
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-8-
scenarios modeled* by the PRPs' contractor. However, the relative
order of the pore volume flush times for the off-property areas
is the same for my modeling and the modeling performed by the
PRPs' contractor.
^ Table ^/Estimated Pore Volume Flush Tinas
Simulation
J.
2
(
2C
3
4
Pumping Entire
Configuration Aquifer
f vears)
intrinsic
on-property recovery
wells, O/welln 15 erom
on-property recovery
wells. O/well • 3 oom
on-property recovery
wells, Q/outer wellse
5 gpm; Q inner wellse
3 upm
on-property recovery
wells with on-property
rein*t ection
on-property recovery
wells with 4 downgradient
j. wells perpendicular to
On- Property
Aquifer
(vears) <
1.1
0.45
0.6
0.53
0.63
0.46
Off -Property
Aquifer
(vears)
9.72
7.94
8
8.5
7.84
on-property recovery
wells with 2 dofwngradient
wells parallel to the
Dlume axis 0.71 3.85
on-property recovery
wells with downgradient
reinSection 0.44 6.41
on-property recovery
wells with downgradient
reinjection (#9 modified
reinHect;ion well locations) 0.49 5.84
10 on-property recovery
wells with 5-well
downgradient reinjection
(#10 modified reinj ection
yell locations) 0.8 5.01
11 on-property recovery
wells with 5-well
downgradient reinjection
and 1 downgradient
recovery well (f 10 modified
reinSection well locations) 0.93 4.93
_7 on-property recovery
n wells with 3 downgradient
wells parallel to the
plume axis 0.57 3.01
8 on-property recovery
\. wells with 8 downgradient
wells perpendicular to
plume 0.71 2^42
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-9-
Table 5 of the report does not include projected on-property pore
volume flush times for simulations 1, 4, 5, or 6. The time for
one on-property pore volume flush is probably significant with
respect to the low mobility ground-water contaminants which are
currently restricted to within the property. My modeling.
predicted slightly different on-property pore volume flush times
for alternatives 4, 5, and 6, which is consistent with variable
configurations of recovery and injection wells.
The additional simulations I performed provide further insight
into the potential optimal configuration of recovery wells.
Simulations 2B and 2C reduce the discharge rate for the four on-
property recovery wells modeled in simulation 2. A reduction in
discharge of on-property recovery wells would decrease the off-
property pore volume flush time, to near ambient conditions.
However, there is a trade off between the time required for one
pore volume flush of contaminated ground water in the capture
zone of the on-property wells and the time required for one pore
volume flush in the areas downgradient of the on-site recovery
well capture zones. Reinjection of contaminated ground water
downgradient of the site would decrease the time required for one
pore volume flush of off-property ground water. Additional off-
property recovery wells could reduce the time required for one
pore volume flush of contaminated off-property ground water to
between 40 and 50% of the time required for one pore volume flush
of contaminated off-property ground water under ambient
conditions. Clearly, some of the simulations I ran which were
not considered by the PRPs' contractor result in more efficient
removal of off-property contaminated ground water than the five
pumping or pumping/reinjection options considered by the PRPs'
contractor.
Section 3.2 Number of Pore Volume Flushes
Section 3.2 presents the equation (batch flushing model) used to
estimate the number of pore volume flushes required to reduce
ground-water contaminant concentrations from an initial value to
a specified end point. The text at the top of page 23 states
that the batch flushing model approach is very conservative,
because other potential factors affecting ground-water transport,
specifically biodegradation, are not considered. Later, in
Section 3.3.1, an equation is presented which incorporates
biodegradation into the calculation of remedial time frames.
I concur with the PRPs' contractor's use of the equation in
Section 3.3.1 to estimate aquifer cleanup times for the
biodegradation case. However, the interpretation of data from
modeling which incorporates biodegradation must be considered
cautiously. This issue is further discussed in this memorandum -
in a review of Section 3.3 of the report.
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-10-
Znitial Concentrations (Report Sections 3.2.1 and 3.2.2)
For the calculation of pore volume flushes required, the PRPs'
contractor used the maximum historical ground-water
concentrations to estimate an initial ground-water concentration
in the batch flush modeling. This approach is probably overly
conservative. I make this conclusion because of the following
reasons:
o Maximum historical concentrations may represent conditions
which are no longer extant (due to biodegradation or contaminant
dispersal over time).
o The highest ground-water concentrations observed may have been
from shallow wells in locations which were part of the soil
remedial action at the site (i.e. the highly ..contaminated ground-
water samples were derived from shallow saturated soils which
were removed) .
o The highest concentrations of contaminants detected in ground-
water samples may have resulted from either earlier ground-water
sampling techniques (high-rate purging of wells) or incomplete
well development ,• which could have resulted in withdrawal of
aquifer materials containing sorbed contaminants.
A conservative alternative approach I used was to consider the
highest average (of detects) concentration in any on-site or off-
site monitoring location in the sand aquifer. This approach may
also over-estimate the remedial time frames required, since it
does not completely eliminate the concerns related to changing
environmental conditions at the site, or sampling technique/well
development. However, "spikes" in contaminant cpncentrations
which may be a result of those conditions (for example, the 79
ug/L chlordane concentration in a sample from well A6-3D) are not
exclusively used to predict remedial time frames. Table 3 of
this memorandum presents the concentrations I selected as initial
values for calculating remedial time frames using the batch
flushing model, or modified batch flushing approach to account
for possible biodegradation below the water table.
Table 3. Maximum Average Concentrations in the Upper Sand Aquifer
On-property wells.
constituent maximum average of detects/veil represented
PCP 1016 ug/L (well OW-2A)
benzene 50.4 ug/L (well OW-2A)
1,1-DCB 22.6 ug/L (well AB-2D)
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-11-
\
Table 3, continued
constituent maximy* pyeraae of detects/well represented
chlordane 32.3 (well AB-3D)
endrln 7.8 ug/L (well OW-1A)
heptachlor epoxlde 0.273 (well AB-7D)
Off- property
constituent mauciBnin average of detects/well represented
PCP 345 ug/L (well AB-13D)
benzene 12.7 ug/L (well AB-13D)
1,1-DCB 27.3 ug/L (well AB-9D)
Retardation Coefficients (Report Section 3.2.3)
With the exception of pentachlorophenol, Koc values used by the
PRPs' contractor are values from a reference by Jeng, et "al,
1992. A more recent US EPA reference, Soil Screening
Guidance;Technical Background Document (US EPA Office of
Emergency and Remedial Response, Washington DC, Publication
9355.4-17A, 1996) presents some Koc data which I used in place of
the PRPs' contractor's Koc values shown in report Table 8.
Values I used are included in Table 4 of this memorandum.
Table 4. Koc Values
•/
constituent reported average Koc (from Table 38. US EPA. 1996)
PCP .use PRPs' contractor's value of 1,439
benzene 66
1,1-DCB 65
chlordane 51,796
endrin 11,422
heptachlor epoxide use PRPs' contractor's value of 7,236
To calculate the soil-water partitioning coefficient, K,,, and the
retardation coefficient, I used the PRPs' contractor's value of
0.00037 for the fraction of organic carbon, and the values of 1.5
g/cm3 for bulk density and 0.39 for porosity (see bottom of
report page 25} . Combined with the Koc values from Table 4 of
this memorandum, use of these values resulted in the Kd and
retardation coefficient presented in Table 5 of this memorandum.
Table 5. Kd and Retardation Coefficient Values
con B t i tuent Kd Retardation coefficient
PCP 0.53 3.05
benzene 0.024 1.09
1,1-DCB 0.024 1.09
chlordane 19.17 74.7
endrin 4.23 17.3
heptachlor epoxide 2.68 11.30
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-12-
Based on the retardation coefficients and maximum average ground-
water .concentrations presented in Table 3 and Table 5 of this
memorandum, I have calculated the required number of pore volume
flushes required to remediate the ground-water in the upper sand
aquifer to the ground-water performance standards, assuming no
biodegradation is occurring. As did the PRPs' contractor, I used
the equation presented in report 3.2, bottom of page 22. My
results in Table 6 of this memorandum can be compared to Table 9
of the report. The results for the off-property conditions are
very similar; my analysis indicates fewer pore volume flushes
will be required for the on-property remedial action, although
the number of required pore volume flushes for chlordane is still
very high.
Table 6. Number of Pore Volume Flushes
contaminant on-property of f -property
PCP 21 18
benzene 2.5 1.6
1,1-DCE 1.3 1.48
chlordane 208
endrin 63.4
heptachlor epoxide 3.5
Section 3.3 Aquifer Cleanup /Times
Biodegradation Analysis
Biodegradation may be occurring at the site. There are site-
specific data from the Remedial Investigation Report (US EPA,
1990) which suggest biodegradation of some organic contaminants
has occurred. Specifically, ground-water detections of
heptachlor epoxide, endrin ketone, oxychlordane, • and
tetrachlorophenol are possible or probable indicators of
biodegradation of heptachlor, endrin, and pentachlorophenol, Some
of these compounds may however represent impurities in the
pesticides which were released to the subsurface during the
facility operations. For the more mobile volatile organic
compounds, one must question the presence of significant
biodegradation, considering the very long contaminant plumes
which have developed downgradient of the Arlington Blending site,
and the absence of significant volatile organic compound
concentration decreases in several monitoring locations over the
life of site monitoring (see report Appendix E, data for wells
AB-2D AB-9D, AB-13D, AB-15D) .
As another example of this concern about biodegradation of the
volatile organic compounds, considering the estimated pore volume-
flush time of 7.67 years I calculated for ambient conditions
-------
-13-
(Table 2 of this memorandum), a retardation factor of 1.09 years
for 1,1-DCS (Table 5 of this memorandum), and the reported
maximum 0.362-year 1,1-DCE half life (report Table 10), 1,1-DCB
transported in the upper sand aquifer to the location of
monitoring well AB-9D should have gone through approximately 23
half lives along its transport path downgradient of the Arlington
Blending property. Considering the average concentration of 1,1-
DCB detected in samples from well AB-9D (27.3 ug/L; see
memorandum Table 3), the initial ground-water concentration
producing 27.3 ug/L through 20 half lives is calculated to be
more than 200,000 mg/L. There is no evidence for on-property
concentrations of 1,1-DCE or related chlorinated organic solvents
approaching such concentrations in soil or ground-water samples
from the Arlington Blending property.
Consistent with the PRPs' contractor's approach, one can consider
biodegradation processes for the sake of comparison of remedial
times for the various ground-water remedial alternatives.
However, one should consider that predicted remedial time frames
incorporating biodegradation may predominantly be influenced by a
process which is not occurring in the ground water, or which may
be occurring at a rate less than that reported in the literature.
Thus, the remedial time frames calculated for the biodegradation
case should be assumed to represent the low-end estimate of the
remedial time frames which may be attainable for the various
remedial options. ,/
Biodegradation half lives presented in Table 10 of the report are
acceptable for this analysis, with the possible exception of
endrin. Available literature references indicate potential half-
life of endrin in soils is as much as 14 years (ATSDR
Toxicological Profile for Endrin/Endrin Aldehyde; Howard,
Handbook of Environmental Fate and Exposure Data for Organic
Chemicals. Volume III). A half life of 14 years is equivalent to
a biodegradation rate coefficient of 0.0495/y. I have only
considered biodegradation for the less mobile pesticide
compounds, since these compounds are most critical to a
comparison of remedial time frames, and there is evidence which
suggests that significant biodegradation of the volatile organic
compounds is not occurring at this site.
Tabulations of Aquifer Cleanup Times
The following series of tables present my calculations of aquifer
cleanup times on a contaminant-specific basis, for each of the
eleven remedial scenarios I modeled. These tables are arranged
differently, but can be compared to report Tables 11 through 14.
A comparison and analysis is made on a contaminant by contaminant
basis, following the tables.
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-14-
V.
aouifer cleanup times j^jio^biodearadation
PCP 21 on-property PV flushes, 18 off-property PV flushes
remedial scenario ft estimated remedial cleanup time, years
on-property off-property
1 (intrinsic remediation) 23.1 138
2 9.4 175;
2B 12.6 143
2C 11.1 144
3 13.2 153
4 9.7 141
5 14.9 69
6 9.2 115
.7 12 54
8 14.9 44
9 10.3 105
10 16.8 90
11 19.5 89
aquifer cleanup times- biodearadation
remedial scenario # estimated remedial cleanup time, years
1 (intrinsic remediation)
2
2B
2C
3
4
5
6
7
8
9
10
11
pn-property
15
7.7
9.7
7.5
10.1
7.9
11
7.6
9.4
11
8.3
12
13.4
off -property
28.1
29.4
28.3
28.4
28.7
28.3
23.4
27
21.3
19.4
26.4
25.4
25.2
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-15-
aquifer cleanup times^ no biodearadation
contaminants benzene 2.5 on-property PV flushes, 1.6 off-property pv
flushes
remedial scenario ft estimated remedial cleanup time, years
l (intrinsic remediation)
2
2B
2C
3
4
5
6
7
8
9
10
11
on -property
2.8
1.1
1.5
1.3
1.6
1.2
1.8
1.1
1.4
1.8
1.2
2
2.3
off ^property
12.3
15.6
12.7
12.8
13.6
12.5
6.2
10.3
4.8
3.9
9.3
8
7.9'
aquifer cleanup times- no biod'egradation
contaminants 1,1-DCE 1.3 cm-property PV flushes, 1.48 off-property PV
flushes
remedial scenario ft estimated remedial cleanup time, years
on-property off-property
1 (intrinsic remediation) 1.4 11.4
2 0.6 14.4
2B 0.8 11.8
2C 0.7 11.8
3 0.8 12.6
4 0.6 11.6
5 0.9 5.7
6 0.6 9.5
7 0.7 4.5
8 0.9 3.6
9 0.6 8.6
10 1 7.4
11 1.2 7.3
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-16-
aguifer cleanup times- no biodegradation
contaminants heptachlor epoxlde 3.5 on-property PV flushes
remedial scenario # estimated ^remedial cleanup time. years
on-property
1 (intrinsic remediation) 3.85
2 1.6
2B 2.1
2C 1.9
3 2.2
4 1.6
5 2.5
6 1.5
7 2
8 2.5
9 1.7
10 2.8
11 3.3
aquifer cleanup times- biodegradation
contaminant t heptachlor epoxide
remedial scenario # estimated remedial cleanup time, years
on-property
1 (intrinsic remediation) 1.0
2 0.6
2B 0.8
2C 0.8
3 0.8
4 0.7
5 0.9
6 0.7
7 0.8
8 0.9
9 0.8
10 1.0
11 1.0
-------
-17-
aquifer cleanup tiroes- no biodearadation
contaminants chlordane 208 on-property PV flushes
remedial scenario ff estimated remedial cleanup time, years
on-property
1 (intrinsic remediation) 229
2 93.6
2B 125
2C 110
3 131
4 96
5 147
6 92
7 118
8 147
9 102
10 166
11 193
aquifer cleanup times- biodearadation
contaminant t chlordane
remedial scenario # estimated remedial cleanup time, years
on-property
1 (intrinsic remediation) 26.9
2 23
2B 24.5
2C 23.9
3 24.8
4 23.1
5 25.3
6 22.9
7 24.3
8 25.3
9 23.5
10 25.8
11 26.4
-------
-18-
aquifer cleanup times- no biodegradation
contaminant • endrin 63.4 on-property PV flushes
on-property
1 (intrinsic remediation) 69.7
2 28.5
2B 38
2C 33.6
3 39.9
4 29.2
5 45
6 27.9
7 36.1
8 45
9 31.1
10 50.7
11 59
aquifer cleanup times, biodegradation
contaminant: endxin
remedial scenario # estimated remedial cleanup time, years
on-property
1 (intrinsic remediation) 35.9
2 20.6
2B 25.1
2C 23.1
3 25.9
4 20.9
5 28
6 20.2
7 24.2
8 28
9 21.9
10 30.1
11 32.8
Pentachlorophenol Comparison and Ana lye is
The PRPs' contractor determined an aquifer cleanup time of 308
years for the intrinsic remediation alternative without
biodegradation, and a cleanup time of 48 years with
biodegradation (report Table 11) . My analysis determined an
aquifer cleanup time of 138 years without biodegradation and 28.1
years with biodegradation for the pentachlorophenol remediation. ~
Report Tables 13 and 14 present remedial time frames for off-
-------
-19-
property intrinsic remediation of 255 and 33 years, without and
with biodegradation respectively. My analysis presents a range
of off-property intrinsic remedial time frames, depending on the
on-property pumping plan considered. For example, for conditions
simulated by ground-water flow model scenario 2 (memorandum Table
2), I predict off-property cleanup times of 175 years and 29.4
years respectively for no biodegradation and biodegradation
conditions. However, for the lower pumping rates modeled in
scenario 2B, the times required for off-site intrinsic
remediation are closer to the time 'frames for intrinsic
remediation of the entire plume.
For conditions where biodegradation is assumed, there is
relatively little advantage obtained by an active ground-water
remedial action. ' For the overall most efficacious active
remedial alternatives considered (simulations 7 and 8), predicted
aquifer cleanup times are reduced from 15 years to approximately
9 to 11 years for on-property remediation, and from 28.1 to
approximately 20 years for off-property remediation.
Where biodegradation is not considered, there is a more dramatic
difference, particularly for the .off-property remedial time
frame. For alternative 8, the predicted remedial time frame for
off-property pentachlorophenol contamination decreases from 138
years to 44 years. With a very low degree of biodegradation, an
active ground-water remedial action may attain remedial goals in
a reasonable time frame (roughly somewhere between 20 to 30
years), while an intrinsic remedial alternative may not attain
remedial goals in the off-property part of the plume in less than
50 years.
Benzene Comparison and Analysis
The PRPs' contractor determined an aquifer cleanup time of 32
years for the intrinsic remediation alternative without
biodegradation, and a cleanup time of 7 years with biodegradation
(report Table 11). My analysis determined an aquifer cleanup
time of 12.3 years without biodegradation; I did not consider
biodegradation but it would result in a predicted remedial time
comparable to the PRPs' contractor's 3-year'time frame. Report
Tables 13 and 14 present remedial time frames for off-property
intrinsic remediation of 12 and 2 years, without and with
biodegradation respectively. My analysis presents a range of
off-property remedial time frames, depending on the on-property
pumping plan considered. Without biodegradation^ the off-
property aquifer cleanup times for benzene could be reduced from
about 12 to 16 years for completely intrinsic off-property
remediation to between 4 and 5 years, for the most effective
active off-property remedial alternatives considered.
-------
-20-
Considering the much longer times required for remediation of
pentachlorophenol under any of the remedial alternatives, it is
unnecessary to include additional discussion of remediation of
the benzene contamination in this memorandum.
1,1-DCE Comparison and Analysis
The PRPs' contractor determined an aquifer cleanup time of 21
years for the intrinsic remediation alternative without
biodegradation, and a cleanup time of 1 year with biodegradation
(report Table 11). My analysis determined an aquifer cleanup
time of 11.4 years without biodegradation for the intrinsic
remediation alternative. My analysis presents a-range of off-
property remedial time frames, depending on the on-property
pumping plan considered. Without biodegradation, the off;
property aquifer cleanup times for 1,1-DCE could be reduced from
about 11 to 15 years for completely off-property Intrinsic
remediation to between 4 and 5 years for the most effective
active off-property remedial alternatives considered.
Considering the much longer times required for remediation of
pentachlorophenol under any of the remedial alternatives, further
discussion of the 1,1-DCS contamination is unnecessary.
Heptachlor Epoxide Comparison and Analysis
The highest detected level of heptachlor epoxide is only
marginally above the ground-water remedial goal concentration
(0.273 ug/L versus 0.2 ug/L). Based on this difference, the time
required for on-property remediation of this compound would not
be expected to be substantial. The PRPs' contractor predicted
the number of pore volume flushes required to reduce this
compound to the ground-water target concentration would be 4,
while my analysis indicated 3.5 on-property flushes would be
required. Under an intrinsic remediation alternative without
biodegradation, the PRPs' contractor determined an aquifer
cleanup time of 43 years, whereas I determined a remedial time of
only 3.85 years. The difference between these estimates partly
relates to the consideration of the fate of heptachlor epoxide
downgradient of the Arlington Blending property. Based on an
evaluation of available ground-water data, I have concluded that
there is probably insufficient heptachlor epoxide mass in the
ground water or saturated soils beneath the property to cause
future off-property contamination above the ground-water remedial
goal of 0.2 ug/L. Thus, on-property flushing of heptachlor
should result in adequate remediation of the heptachlor epoxide
ground-water contamination within a few years. There is probably
very little to be gained by an on-property active remedial action
to address the heptachlor epoxide contamination.
-------
-21-
Chlordane Comparison and Analysis
;i
The PRPs' contractor determined an aquifer cleanup time of 2,892
years for the intrinsic remediation alternative without -
biodegradation, and a cleanup time of 40 years with
biodegradation (report Table 11). My analysis determined an
aquifer cleanup time of 229 years without biodegradation and 26.9
years with biodegradation for the chlordane remediation. Similar
to the situation for heptachlor epoxide, the large discrepancy
between my estimate and the PRPs' contractor's estimate relates
to the potential for off-property migration of chlordane. Based
on my analysis of data for on-property chlordane contamination,
and considering the low mobility of this compound, there is
little likelihood that a chlordane plume will extend for any
significant distance downgradient from the property. Thug, the
entire aquifer downgradient of the property would probably not
have to be flushed over 200 times in order to reduce chlordane
concentrations to below ground-water target levels throughout the
area of concern.
However, my analysis does indicate that in the absence of
biodegradation, a very long time will probably be needed to
reduce chlordane concentrations to below target levels throughout
the area of ground-water chlordane contamination^ The most
efficacious on-property remedial alternative may not reduce
chlordane concentrations to acceptable concentrations for almost
100 years, if there is no significant biodegradation.
Conversely, if there is significant biodegradation such as that
modeled in this memorandum, there is little to be gained in
chlordane remediation for an active remedial alternative, versus
the intrinsic remedial alternative (the predicted aquifer cleanup
time would decrease from approximately 27 years to approximately
23 years) . Thus, one might conclude that remediation of the
ground-water chlordane contamination is either ill-advised not
warranted (i.e. is either unnecessary if there is significant
biodegradation, or is * technically impracticable", if there is no
biodegradation) . , There may be some intermediate condition of
very minimal biodegradation where there is more advantage to an
active remedial action for chlordane ; also, should the chlordane
mobility and contaminant mass conditions be'less favorable than I
believe, there may be some need to contain this chlordane
contamination to within the property. However, one could
conclude from this analysis that the chlordane ground-water
contamination would be best monitored rather than directly
addressed through any active ground-water remedial action until
and unless conditions change.
-------
-22-
Endrin Comparison and Analysis
The PRPs' contractor determined an aquifer cleanup time of 755
years for the intrinsic remediation alternative without
biodegradation, and a cleanup time of 45 years with . ...
biodegradation (report Table 11) . My analysis determined an
aquifer cleanup time of 69.7 years without biodegradation and
35.9 years with biodegradation, for the intrinsic endrin
remediation. The discrepancy again relates to the PRPs'
contractor's assumption that the endrin will spread into areas
downgradient of the property and must be flushed out of the
aquifer at the ground-water discharge area along the Loosahatchie
River canal, versus my conclusion that such contamination is
unlikely to occur. Regardless, there appear to be advantages to
on-property active remedial action to address this compound, if
there is no biodegradation occurring in the ground water. My
analysis indicates that remediation of the on-property endrin
ground-water contamination can be reduced from approximately 70
years to approximately 30 years, in the absence of significant
biodegradation.
As for other contaminants, there is relatively less advantage for
an active remedial action if there is significant biodegradation
of endrin. However, there is probably more advantage to an
active remedial option for endrin than for the other low mobility
pesticides chlordane and heptachlor epoxide. Cleanup times for an
active on-property remedial action to address endrin
contamination may be reduced by roughly 40% if there is
biodegradation occurring to the degree considered in the
modeling; reduction in cleanup time is predicted to be
approximately 15% at most for chlordane, while the heptachlor
epoxide contamination should decrease to below target
concentrations in a year or less, regardless of the remedial
alternative considered.
Section 4.0 Memphis Sand Pumping Simulations
I have not independently modeled the conditions which would occur
under this aquifer pumping scenario. However, based on the
available site data and the conceptual model presented elsewhere
in the report, as well as volumes of leakage calculated by the
calibrated Modflow model for the ambient conditions, I concur
that there should be an insignificant amount of leakage from the
upper sand aquifer to the Memphis sand aquifer in the area of
concern.
-------
-23-
References
Agency for Toxic Substances and Disease Registry, (ATSDR), 1994,
Toxicological Profile for Endrin/Endrin Aldehyde (draft report).
Howard, Philip H., 1991, Handbook of Environmental Fate and
Exposure Data for Organic Chemicalp. Volume III, Lewis
Publishers, Chelsea, Michigan.
US EPA Office of Emergency and Remedial Response, Washington DC,
1996, Soil Screening Guidance:Technical Background Document,
Publication 9355.4-17A.
US EPA, 1990, Remedial Investigation Report, report prepared by
the US EPA, Region IV.
-------
Appendix A
-------
pathline t interval IflOd
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363 900
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------- |