FOCUSED FEASIBILITY STUDY, OU 1 (COVER LETTER ATTACHED)

MILLER, INC.Environment and Infrastructure

a heidemij company

September 16, 1996

Mr. Eugene DennisRemedial Project ManagerUSEPA, Central Pennsylvania Remedial Section (3HW27)841 Chestnut BuildingPhiladelphia, Pennsylvania 19107

***^

Re: Focused Feasibility Study, Operable Unit No. 1, AVCO Lycoming SuperfundSite, Williamsport, Pennsylvania.

Dear Mr. Dennis:

Enclosed, please find the original and two copies of the "Focused FeasibilityStudy, Operable Unit No. 1, AVCO Lycoming Superfund Site, Williamsport,Pennsylvania".

Please call if you have any questions or require additional information.

Sincerely,

GERAGHTY & MILLER, INC.

John P. MihalichProject Manager

cc: Randy Farmerie - PADEP (3 copies)Lee Trefsger - AVCO (3 copies)James Runstadler - Textron, Inc.

g:project/textron/fs/covlt996.doc

3000 Cabot Boulevard West. Suite 3004 • Langhome, Pennsylvania 1904f l R 3 0 0 ! 3 3

TI

.i ' FOCUSED FEASIBILITY STUDY

OPERABLE UNIT NO. 1f AVCO LYCOMBVG SUPERFUND SITEi WILLIAMSPORT, PENNSYLVANIA

September 1996

Prepared for

Textron Lycoming,a Division of AVCO Corporation

652 Oliver StreetWilliamsport, Pennsylvania 17701

i Prepared by

rGeraghty & Miller, Inc.

f 3000 Cabot Boulevard Westi - Suite 3004

Langhorne, Pennsylvania 19047i , (215)752-6840

f ir

FOCUSED FEASIBILITY STUDYOPERABLE UNIT NO. 1

AVCO LYCOMING SUPERFUND SITEWBLLIAMSPORT, PENNSYLVANIA

September 13,1996

Prepared by GERAGHTY& MILLER, INC

John P. MihalichProject Manager

Suthan S. Suthersan, Ph.D., P.E.Vice President - Director of Engineering

GERAGHTY & MILLER, INC.A R 3 0 0 I 3 5

EXECUTIVE SUMMARYFOCUSED FEASIBILITY STUDY

OPERABLE UNIT NO. 1AVCO LYCOMING SUPERFUND SITE

WILLIAMSPORT, PENNSYLVANIA

INTRODUCTION

"^Geraghty & Miller, Inc. was retained by Textron Lycoming, a Division of AVCO

Corporation (AVCO), to conduct a focused feasibility study (FFS) for Operable Unit No. 1(OU-1) at the AVCO Lycoming Superfund site in Williamsport, Pennsylvania. The FFS was

requested by the U.S. Environmental Protection Agency (EPA) to support an amendment to theJune 28, 1991 Record of Decision (ROD) based on an evaluation of alternate technologies. The

purpose of the FFS is to evaluate site-related conditions and monitoring data and to propose a

more-appropriate and cost-effective alternative to the groundwater extraction and treatment-remedy presented in the ROD. OU-1 addresses only the on-site contaminated groundwater.

The remedy selected by the ROD was groundwater pumping to contain and collect

contaminated groundwater on-site, aboveground treatment of recovered groundwater for metals,

aboveground air stripping for volatile organic compounds (VOCs) in recovered groundwater,emissions controls, and discharge of treated groundwater to Lycoming Creek. The alternate

remedy consists of in-situ air sparging/soil vapor extraction (AS/SVE) to address VOCs higroundwater and in-situ metals precipitation for metals. These alternate in-situ technologieseliminate the need for aboveground treatment and disposal of recovered groundwater.

AS/SVE and metals precipitation pilot tests were performed to evaluate the applicability

of these in-situ technologies at the site and to collect the information necessary to design full-

scale remediation systems. The pilot tests demonstrate that the in-situ technologies (AS/SVE toaddress the VOCs and metals precipitation to address metals) are applicable to the site. In

A R 3 0 0 I 3 6GERAGHTY & MILLER, INC.

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addition to containment of contaminated groundwater on-site, the alternate remedy includes

source reduction, thereby reducing the cleanup time.

SUMMARY OF ENVIRONMENTAL DATA

For the overburden aquifer, the 1991 RI report concluded the following:

«»-• groundwater flow in the overburden aquifer is primarily to the south, with minor

components of flow to the southeast and southwest;

• trichloroethene (TCE), total 1,2-dichloroethenes (DCE), vinyl chloride, andchromium are the primary overburden groundwater contaminants;

• the extent of the TCE-DCE overburden plume has been defined to the west,

southwest, and the southeast in the study area, with the southern extent of theplume reaching Third Street;

• vinyl chloride has been detected in the overburden only in on-site monitoringwells;

• the hexavalent chromium and total chromium contamination is limited to the

western section of the plant in the vicinity of the old human resources buildingand old wastewater treatment plant (WWTP) and has migrated to a limited degreeoff site in s a southerly direction.

For the bedrock aquifer, the RI report concluded the following:

• the source for the bedrock contamination is thought to originate within theoverburden contaminant sources:

• the bedrock and overburden aquifers are hydraulically connected;• the primary contaminants in the bedrock aquifer are TCE, DCE, and vinyl

chloride.

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Air sparging/soil vapor extraction pilot tests were performed in October 1995 to evaluate

the applicability of the technology to the site and to collect the information to design a full-scaleremediation system. The results of the pilot tests demonstrated the following:

soil vapor extraction influence is estimated to range from approximately 27 to 57 feet,

depending on location within the site;

air sparging influence was observed to range from approximately 18 to 20 feet;

VOC concentrations in soil gas extracted during the test increased as a result of air

sparging, indicating that AS/SVE is a viable remedial alternative for in-situ treatmentof VOCs in groundwater at the site; and

mass removal rates are dependent on existing concentrations of VOCs in groundwaterwithin the effective radius of the system and the rate of replenishment resulting from

groundwater migration.

The six-month in-situ metals precipitation pilot test was performed from November 1995

through May 1996. The pilot test demonstrated the following:

• reducing conditions and a significant decrease in hexavalent chromium concentrations

were observed within approximately nine days after injection of the molassessolution;

• during the test, concentrations of hexavalent chromium decreased from as high as 7.0

milligrams per liter (mg/L) to less than the detection level. The concentration of totalchromium also decreased during the test;

• based on data collected during the pilot test, individual injection wells had reactivezones ranging in width from 25 to 40 feet in a downgradient direction; and

• in-situ metals precipitation is a viable remedial alternative for the site.


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DEVELOPMENT AND SCREENING OF REMEDIAL ALTERNATIVES

Based on the results of the RI, the nature and extent of contamination, and the riskassessment, the following remedial action objectives (RAOs) were established for the site as part

oftheFS:

• Contamination will be mitigated such that ARARs are met in the overburden and

—- bedrock"aquifers to the extent practicable.• Off-site movement of contaminated groundwater from either the overburden or

bedrock aquifers on-site will be prevented to the extent possible.

The general response actions (GRAs) identified are as follows:

• Containment: This measure restricts migration of on-site contaminated,

groundwater past site boundaries.

• Removal: This action entails collection of groundwater for treatment or disposal,which can, by its nature, achieve a high degree of groundwater containment.

• Treatment: This category consists of biological or physical/chemical treatment ofgroundwater above ground or in-situ.

• Disposal: Options discussed under disposal include off-site discharge of treated

groundwater.

Alternative 1 (groundwater pump and treat) and Alternative 2 (air sparging/soil vapor

extraction and in-situ metals precipitation) were evaluated against seven of the nine evaluationcriteria in conformance with EPA and the National Contingency Plan (NCP) guidance. The

remaining two criteria, supporting agency and community acceptance, are typically evaluated ata later stage.

A R 3 0 0 1 3 9GERAGHTY & MILLER, INC.

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Following the analysis of the two potential remedial alternatives for the site, Geraghty &

Miller recommends that Alternative 2 be implemented as the remedial action. Overall,

Alternative 2 satisfies the objectives of the evaluation criteria more effectively than Alternative1, as explained below.

OVERALL PROTECTION OF HUMAN HEALTH AND THE ENVIRONMENT

-•^For overall protection of human health and the environment, no unacceptable risks are

associated with current groundwater use in the area, because of the treatment system at theWilliamsport Municipal Water Authority (WMWA) well field. Alternatives 1 and 2 minimize

off-site migration of contaminants in groundwater flowing from the site. In addition, Alternative2 provides better overall protection of human health and the environment because the

remediation time is shortened.

COMPLIANCE WITH ARARS

Both alternatives can be designed and implemented with the objective of satisfying theARARs. However, Alternative 2 may achieve compliance with ARARs more quickly than

Alternative 1.

LONG-TERM EFFECTIVENESS AND PERMANENCE

With respect to long-term effectiveness, both Alternatives 1 and 2 are expected to provide

a high degree of permanence. However, the time to remediation for Alternative 1 is assumed tobe 30 years, while the time to remediation for Alternative 2 is estimated to be less than 10 years.

Alternative 2, therefore, provides a higher degree of long-term effectiveness than Alternative 1.

f t R 3 0 0 I U OGERAGHTY & MILLER, INC.

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In addition, Alternative 2 may provide more long-term effectiveness and permanence

than Alternative 1 because the in-situ technologies address the source of the contaminants (i.e.,

the soil), as well as contain the contaminated groundwater from migrating off-site.

SHORT-TERM EFFECTIVENESS

With respect to short-term effectiveness, there are minimal potential risks associated with

the ce«struction of either alternative.

REDUCTION OF TOXICITY, MOBILITY, OR VOLUME

Alternative 2 is expected to provide the higher degree of toxicity, mobility, or volumereduction, because of the additional reduction in organics afforded by bioremediation associated

with the in-situ technologies. In addition, a significant amount of contaminated waste wouldcontinually be generated by Alternative 1 through the operation of the system, due to the need to

treat recovered groundwater. The amount of waste generated by Alternative 2 is insignificantcompared to the amount that would be generated by Alternative 1.

IMPLEMENT ABILITY

Both Alternatives 1 and 2 are implementable. Although Alternative 2 includes innovative

technologies with associated uncertainties for long-term operation and maintenance, the pilottests performed at the site demonstrate that the technologies are effective at remediation andapplicable to the site.

COSTS

Cost estimates were developed for each of the alternatives. The construction and O&Mcosts for each alternative were estimated conservatively.

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The present worth of costs associated with Alternative 1 was calculated using a discountrate of 6 percent for a 30-year time period, while the costs associated with Alternative 2 using a 6

percent discount rate assumed a 10-year time period. The estimated present-worth cost for each

of the alternatives is as follows:

Alternative 1: $10,000,000

Alternative!: $4,200,«00

A R 3 Q O I U 2GERAGHTY & MILLER, INC.

CONTENTS

Page1 INTRODUCTION...........................................................................................................1-1

1.1 PURPOSE............................................................................................................ 1-21.2 SITE BACKGROUND........................................................................................ 1-2

1.2.1 Nature and Extent of Findings................................................................. 1-41.2.2 Summary of the Remedial Investigation.................................................. 1-51.2.3 Summary of the Risk Assessment............................................................ 1-7

-v 1.2.4 Post ROD Activities................................................................................. 1-9

2 IDENTIFICATION OF REMEDIAL ALTERNATIVES............................................... 2-1

2.1 APPLICABLE OR RELEVANT AND APPROPRIATEREQUIREMENTS (ARARS) AND OTHER CRITERIA.................................. 2-1

2.1.1 Definitions of ARARS and Other Criteria............................................... 2-1

2.1.1.1 ARARs......................................................................................... 2-12.1.1.2 To-Be-Considered(TBC) Materials............................................ 2-2'

2.1.2 Identification of Potential ARARs and TBCs.......................................... 2-2

2.1.2.1 Potential Chemical-Specific ARARs and TBCs.......................... 2-32.1.2.2 Potential Location-Specific ARARs/TBCs.................................. 2-42.1.2.3 Potential Action-Specific ARARs/TBCs..................................... 2-4

2.1.3 Media of Concern.................................................................................... 2-5

2.2 REMEDIAL ACTION OBJECTIVES................................................................ 2-62.3 GENERAL RESPONSE ACTIONS.................................................................... 2-72.4 SCREENING OF REMEDIAL TECHNOLOGIES AND PROCESS OPTIONS2-7

2.4.1 Alternative 1: Groundwater Recovery, Chemical Treatment for Metals,Air Stripping, Emissions Controls, and Discharge of Treated Water..... 2-9

2.4.1.1 Recovery Wells............................................................................ 2-92.4.1.2 Chemical Precipitation............................................................... 2-102.4.1.3 Air Stripping.............................................................................. 2-102.4.1.4 Fume Incineration...................................................................... 2-112.4.1.5 Vapor Phase Carbon Adsorption ...............................................2-112.4.1.6 Stream Discharge....................................................................... 2-11

R R 3 0 Q I U 3GERAGHTY & MILLER, INC.

II

CONTENTS (continued)

2.4.2 Alternative 2: Air Sparging/Soil Vapor Extraction and In-Situ MetalsPrecipitation........................................................................................... 2-12

2.4.2.1 Air Sparging/Soil Vapor Extraction...........................................2-122.4.2.2 In-Well Air Sparging................................................................. 2-122.4.2.3 Metals Precipitation................................................................... 2-132.4.2.4 Vapor Phase Carbon Adsorption............................................... 2-15

3 DEVELOPMENT OF REMEDIAL ALTERNATIVES................................................. 3-1y^ *

3.1 REMEDIAL ACTION ALTERNATIVES.......................................................... 3-1

3.1.1 Alternative 1: Ground-water Recovery, Chemical Treatment for Metal,Air Stripping, Emissions Controls, and Discharge of Treated Water...... 3-1

3.1.2 Alternative 2: Air Sparging/Soil Vapor Extraction and In-Situ MetalsPrecipitation.............................................................................................3-3

4 DETAILED ANALYSIS OF REMEDIAL ALTERNATIVES ...................................... 4-1

4.1 EVALUATION OF REMEDIAL ALTERNATIVES.........................................4-1"

4.1.1 Overall Protection of Human Health and the Environment..................... 4-24.1.2 Compliance with ARARs ........................................................................ 4-24.1.3 Long-Term Effectiveness and Permanence .............................................4-24.1.4 Reduction of Toxicity, Mobility, or Volume........................................... 4-24.1.5 Short-Term Effectiveness ........................................................................4-24.1.6 Implementability......................................................................................4-34.1.7 Cost..........................................................................................................4-3

4.1.7.1 Capital Costs................................................................................4-34.1.7.2 Operation and Maintenance Costs............................................... 4-34.1.7.3 Present-Worth Analysis............................................................... 4-4

4.2 ANALYSIS OF REMEDIAL ALTERNATIVES............................................... 4-4

4.2.1 Alternative 1: Groundwater Recovery, Chemical Treatment for Metals,Air Stripping, Emissions Controls, and Discharge of Treated Water...... 4-4

4.2.1.1 Overall Protection of Human Health and the Environment......... 4-44.2.1.2 Compliance with ARARs............................................................ 4-54.2.1.3 Long-Term Effectiveness and Permanence................................. 4-6

AR300UI4GERAGHTY & MILLER, INC. W

Ill


4.2.1.4 Reduction of Toxicity, Mobility, or Volume............................... 4-64.2.1.5 Short-Term Effectiveness ............................................................4-74.2.1.6 Implementability..........................................................................4-84.2.1.7 Cost..............................................................................................4-94.2.1.8 Supporting Agency and Community Acceptance........................ 4-9

4.2.2 Alternative 2: Air Sparging/Soil Vapor Extraction and In-Situ MetalsPrecipitation.............................................................................................4-9

M». 4.2.2.1 Overall Protection of Human Health and the Environment......... 4-94.2.2.2 Compliance with ARARs.......................................................... 4-104.2.2.3 Long-Term Effectiveness and Permanence............................... 4-114.2.2.4 Reduction of Toxicity, Mobility, or Volume............................. 4-114.2.2.5 Short-Term Effectiveness .......................................................... 4-124.2.2.6 Implementability........................................................................ 4-134.2.2.7 Cost............................................................................................4-144.2.2.8 Supporting Agency and Community Acceptance...................... 4-14

5 COMPARATIVE ANALYSIS OF ALTERNATIVES................................................... 5-1

5.1 OVERALL PROTECTION OF HUMAN HEALTH ANDTHE ENVIRONMENT....................................................................................... 5-1

5.2 COMPLIANCE WITH ARARS.......................................................................... 5-15.3 LONG-TERM EFFECTIVENESS AND PERMANENCE................................ 5-15.4 SHORT-TERM EFFECTIVENESS.................................................................... 5-25.5 REDUCTION OF TOXICITY, MOBILITY, OR VOLUME............................. 5-25.6 IMPLEMENTABILITY...................................................................................... 5-25.7 COSTS.................................................................................................................5-25.8 SUPPORTING AGENCY AND COMMUNITY ACCEPTANCE.................... 5-3

6 RECOMMENDED ALTERNATIVE............................................................................. 6-1

7 REFERENCES................................................................................................................ 7-1

TABLES

2-1 Potentially Applicable or Relevant and Appropriate Requirements (ARARs) and Criteriato be Considered (TBCs), AVCO Lycoming Focused Feasibility Study.

2-2. Identification of Focused Feasible Technology Types and Process Options for On-SiteGroundwater, AVCO Lycoming Superfund Site, Williamsport, Pennsylvania.

A R 3 0 0 I U 5GERAGHTY& MILLER, INC.

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TABLES

2-3. Detailed Screening of Focused Technology and Process Options Retained for On-SiteGroundwater, AVCO Lycoming Superfund Site, Williamsport, Pennsylvania.

FIGURES

1-1. .^Site Location, AVCO Lycoming Superfund Site, Williamsport, Pennsylvania.

1-2. TCE-DCE- Vinyl Chloride, Overburden Plume - October 1995, Textron Lycoming,Williamsport Pennsylvania.

1-3. TCE-DCE in Bedrock Wells, October 1995, Textron Lycoming, Williamsport,Pennsylvania.

1-4. Shallow Water Table, Overburden Aquifer' - October 1995, Textron Lycoming,Williamsport, Pennsylvania.

2-1. Conceptual Flow Diagram For Groundwater Pump and Treat, AVCO LycomingSuperfund Site, Williamsport, Pennsylvania.

2-2. Schematic Diagram, Air Sparging/Soil Vapor Extraction, AVCO Lycoming SuperfundSite, Williamsport, Pennsylvania.

2-3. Schematic Diagram, In- Well Air Sparging, AVCO Lycoming Superfund Site,Williamsport, Pennsylvania.

3-1. Conceptual Location of Groundwater Recovery Wells, AVCO Lycoming Superfund Site,Williamsport, Pennsylvania.

APPENDICES

A. Cost Estimate Details for Alternatives.

A R 3 0 0 U 6GERAGHTY & MILLER, INC.

FOCUSED FEASIBILITY STUDYOPERABLE UNIT NO. 1

AVCO LYCOMING SUPERFUND SITEWILLIAMSPORT, PENNSYLVANIA

1. INTRODUCTION

Geraghty & Miller, Inc. was retained by Textron Lycoming, a Division of AVCOCorporation (AVCO), to conduct a focused feasibility study (FFS) for Operable Unit No. 1

(QtT-1) at the AVCO Lycoming Superfund site in Williamsport, Pennsylvania (Figure 1-1).The FFS was requested by the U.S. Environmental Protection Agency (EPA) to support an

amendment to the June 28, 1991 Record of Decision (ROD) based on an evaluation ot

alternate technologies. OU-1 addresses only the on-site contaminated groundwater.

The remedy selected by the ROD was groundwater pumping to contain and collect

contaminated groundwater on-site, aboveground treatment of recovered groundwater formetals, aboveground air stripping for volatile organic compounds (VOCs) in recoveredgroundwater, emissions controls, and discharge of treated groundwater to Lycoming Creek.

The alternate remedy consists of in-situ air sparging/soil vapor extraction (AS/SVE) toaddress VOCs in groundwater and in-situ metals precipitation for metals. These alternate in-situ technologies eliminate the need for aboveground treatment and disposal of recovered

groundwater.

' AS/SVE and metals precipitation pilot tests were performed to evaluate theapplicability of these in-situ technologies at the site and to collect the information necessaryto design full-scale remediation systems. The pilot tests demonstrate that the in-situ

technologies (AS/SVE to address the VOCs and metals precipitation to address metals) are

applicable to the site. In addition to containment of contaminated groundwater on-site, thealternate remedy includes source reduction, thereby reducing the cleanup tune. Detailsregarding the results of the pilot tests can be found in the April 1996 (AS/SVE) and June1996 (metals precipitation) pilot test reports submitted to the EPA (Geraghty & Miller, Inc.1996a; Geraghty & Miller, Inc. 1996b).

A R 3 Q O U 7GERAGHTY & MILLER, INC.

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1.1 PURPOSE

The purpose of this FFS is to compare and evaluate the remedy selected by the 1991

ROD with the alternate in-situ remedy. The two remedial alternatives (groundwater pumpand treat and in-situ AS/SVE and metals precipitation) are each evaluated for the potential to

reduce the potential human health and environmental risks associated with the constituents of

concern (COCs) identified at the site and to investigate the feasibility of such alternatives.

The purpose of the FFS report is to document the basis and procedures in identifying,

developing, screenmg, and evaluating the remedial alternatives in order to select the mostfeasible and cost-effective remedial alternative for the site.

1.2 SITE BACKGROUND

AVCO manufactures reciprocating aircraft engines which are used primarily in general

aviation. The facility is located on approximately 28 acres adjacent to a residentialneighborhood which also contains some light industry. The following summary of site,

background is based on information found in the ROD (U.S. Environmental Protection

Agency 1991).

In the Fall of 1984, the Williamsport Municipal Water Authority (WMWA) detectedthe presence of VOCs, specifically trichloroethene (TCE) and 1,2-trans-dichloroethene

(DCE), in the groundwater at the backup water-supply well field located south of Third

Street, approximately 3,000 feet south of the AVCO facility. In November 1984, thePennsylvania Department of Environmental Protection (PADEP, formerly the Pennsylvania

Department of Environmental Resources) informed AVCO of this condition and requested asample be obtained from an inactive production well located on site. The analysis ofgroundwater samples collected in December 1984 and January 1985 from this production well

along with samples from other accessible wells in the area lead PADEP to suspect that theAVCO facility was the source of the VOCs. Based on this finding, AVCO performed an

internal investigation in the Winter of 1985. This investigation indicated that volatile organic


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constituents in the overburden groundwater aquifer beneath the plant were migrating from the

plant in a southerly direction.

In November 1985, AVCO entered into a Consent Agreement and Order (COA) with

PADEP. The COA defined a remedial investigation and cleanup plan. The investigations andremedial action program resulted in the installation of 47 groundwater monitoring wells, threeon-site and two off-site recovery wells and associated treatment facilities, and extensive

groundwater and soil sampling analyses depicting distribution of VOCs in the subsurface.^^ *

A separate agreement with the WMWA resulted in the installation of four packedcolumn air stripping towers to treat groundwater withdrawn from the municipal well field.The data also indicated that groundwater underlying the site contained heavy metals, in

particular, total and hexavalent chromium. Groundwater in the overburden has been mostaffected; TCE has also been detected in the bedrock underlying the glacial deposits at the

plant and, to a limited extent, in the upper part of the bedrock southwest of the plant. There'has been no dense, non-aqueous phase liquid (DNAPL) encountered.

In June 1988, AVCO and the EPA executed an Administrative Order of Consent forthe purpose of conducting a Remedial Investigation (RI), Endangerment Assessment (EA),

and Feasibility Study (FS). On June 28, 1991, a ROD was issued for the area within the plantboundaries and on May 7, 1992, the EPA issued AVCO an Administrative Order (AO) toimplement the remedy. The Remedial Design (RD) Work Plan was approved by the EPA on

December 16, 1992 and work identified in this plan was initiated.

The selected remedy for the site, as described in the June 28, 1991 ROD, is

groundwater extraction and aboveground treatment. Remedial design activities weresuspended pending establishment of National Pollutant Discharge Elimination System

(NPDES) limits which are necessary to ensure proper design of this type of treatment system.AVCO received the NPDES permit on July 25, 1995.


1-4

1.2.1 Nature and Extent of Findings

During the RI for the site, groundwater samples were collected to characterize the

COCs. Quarterly groundwater sampling was initiated in 1988 and continues to the present. Asummary of the groundwater data is presented below based on the sampling performed in thefourth quarter 1995. Fourth quarter results are summarized here rather than more recent

sampling events since the required fourth quarter sampling involves a more comprehensivesampling of on-site wells than the other three quarters.

The primary organic constituents of concern in the overburden aquifer are TCE andDCE. Vinyl chloride and, to a lesser extent, chromium are also present.

The configuration of the combined TCE-DCE-vinyl chloride plume in the overburden

aquifer as interpreted from the fourth quarter 1995 sampling data is presented in Figure 1-2.Fourth quarter 1995 sampling data from the bedrock aquifer are shown in Figure 1-3. There"are three areas of the site that have elevated concentrations of VOCs.

The first area showing elevated concentrations is the area near wells MW-9 and

MW-20. This area contains total TCE-DCE-vinyl chloride concentrations of up to 16,400ug/L based on the fourth quarter 1995 data. MW-9 is located close to a former drum and

bottle storage area and the former rail line. Contamination in this area has not migrated of-sitein the southeast direction to any significant extent based on data from downgradient wells,such as MW-12 and MW-74.

The second area showing elevated concentrations is in the central portion of the site in

the vicinity of well MW-50. This area contains total TCE-DCE-vinyl chloride concentrationsof up to 8,500 ug/L based on the fourth quarter 1995. This area is near several identifiedareas of concern, including a former dry well and the chipster sump.


1-5

The third area showing elevated concentrations is located beneath the western portionof the site near the old wastewater treatment plant (WWTP), the old Human ResourcesBuilding, and the Oliver Street storm sewer. The monitoring wells with the highest TCE-

DCE-vinyl chloride concentrations in this area are MW-3R and MW-18, which had totalconcentrations of 331 and 394 ug/L, respectively, during the fourth quarter 1995.

Inorganic constituents are also present in groundwater in the western portion of thesite. Prior to the six-month field design test for in-situ metals precipitation, concentrations of-w •

total chromium (filtered) ranged from 1.65 to 5.14 mg/L, concentrations of hexavalentchromium ranged from 2.1 to 7.0 mg/L, and concentrations of cadmium (filtered) ranged from

0.0021 to 0.883 mg/L. Monitoring well MW-31, located off-site approximately 500 feet

south of the old WWTP, showed hexavalent chromium at 0.102 mg/L during the August 1990sampling event.

1.2.2 Summary of the Remedial Investigation

The results of the RI indicate that there are two primary contaminant plumes for

volatile organics and one localized plume for chromium (ERM 1991). One organics plume isgenerally migrating south in the overburden aquifer in the direction of groundwater flow

Figure 1-4). The second organics plume is migrating in the bedrock aquifer with the

southwest component of groundwater flow along the strike of the underlying bedrock (theTully Formation). The plume in the bedrock extends from the plant southwest to the upperzone of the bedrock beneath Elm Park. As reported in the RI, the vertical head relationshipsin the bedrock aquifer indicate that groundwater from the bedrock discharges into the

overburden aquifer in the vicinity of Elm Park. In addition, bedrock wells in Elm Parkscreened at lower elevations do not contain organic compounds above method detectionlimits. There is also the likelihood that the source of the VOCs in bedrock is the storm sewerdischarge at Elm Park, rather than the migration from the overburden. The chromium plumeoriginates in the vicinity of the old WWTP and is generally migrating south in the overburden

aquifer in the direction of groundwater flow.

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For the overburden aquifer, the RI report (ERM 1991) concluded the following:

• groundwater flow in the overburden aquifer is primarily to the south, with

minor components of flow to the southeast and southwest;• TCE, DCE, vinyl chloride, and chromium are the primary overburden

groundwater contaminants;

• the extent of the TCE-DCE overburden plume has been defined to the west,southwest, and the southeast in the study area, with the southern extent of the

plume reaching Third Street;

• the TCE and DCE groundwater plumes are similar in overall configuration andhave not changed in that respect since sampling began in 1985;

• vinyl chloride has been detected in the overburden only in on-site monitoringwells;

• other organic compounds detected in the overburden plume are chloroform,

1,1-dichloroethane, 1,1-dichloroethene, and toluene; these compounds havebeen detected on site at parts per billion (ppb) concentrations;

• the only semivolatile compound detected in the overburden beneath the plant(MW-50) is a trace concentration (2 ppb) of 1,2-dichlorobenzene;

• one on-site well (MW-3) had detectable concentrations of the pesticides beta

BHC and delta-BHC at trace concentrations (0.05 and 0.08 ppb, respectively);• the hexavalent chromium and total chromium contamination is limited to the

western section of the plant in the vicinity of the old human resources building

and old WWTP;• the chromium plume has migrated to a limited degree off site in a southerly

direction;

• the overburden aquifer thickness ranges from 4 to 18 feet beneath the plant andfrom 23 to 37 feet off site; and, approximately 100 gpm of groundwater flows

through that portion of the overburden aquifer underlying the facility.


1-7

For the bedrock aquifer, the RI report (ERM 1991) concluded the following:

• the source for the bedrock contamination is thought to originate within theoverburden contaminant sources:

• the bedrock and overburden aquifers are hydraulically connected;

• the primary contaminants in the bedrock aquifer are TCE, DCE, and vinylchloride;

• TCE, DCE, and vinyl chloride were detected in bedrock wells MW-8D and

MW-62 on site;• vinyl chloride has been detected in only one off-site bedrock well (MW-65), in

the Tully Formation, at a concentration of 1 ppb, which is below drinking

water standards;• the primary migration pathway for contaminants in the bedrock aquifer

corresponds to the primary bedrock groundwater flow direction, to the

southwest;

• groundwater yields in the bedrock aquifer are variable, ranging from less than 1gpm to 35-40 gpm in the bedrock beneath Elm Park; and

• based on calculations completed since submittal of the RI, an estimated 30 to90 gpm flows through the bedrock aquifer in the Tully Formation beneath the

facility.

1.2.3 Summary of the Risk Assessment

The risk assessment, which was performed as part of the RI, focused on the following:

1) the constituents detected during the RI; 2) the potential environmental pathways by whichpopulations might be exposed to compounds released from the site; 3) the estimated exposurepoint concentrations of the compounds of concern; 4) applicable or relevant and appropriate

requirements (ARARs), criteria, and advisories; 5) the estimated intake levels of the

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compounds of concern; and 6) the toxicity values of the compounds of concern (ERM, 1991).The level of risk that the site poses to human health was then quantified.

The following constituents were considered during the risk assessment are the

following: TCE, DCE, vinyl chloride, toluene, benzo(a)pyrene, hexavalent chromium,

cadmium, manganese, lead, barium, and beryllium. The risk assessment identified 11 exposurescenarios that were associated with groundwater, soil, surface water, air, and sediment at and

around the AVCO Lycoming site. Risks resulting from analysis of six of the exposurescenarios are at or below the acceptable level. Unacceptable risks were associated with theremaining five scenarios. As stated in the ROD, the only media of concern at the AVCO

Lycoming site is through exposure to groundwater.

Conclusions of the risk assessment as summarized in the previous FS (ERM, 1991)

were as follows:

• Reasonable and worst-case estimates of feasible lifetime cancer risk for Scenario A(use of treated groundwater from the WMWA production wells), use of Lycoming

Creek, vapors off-gassing from soils, and air emissions from existing air strippingtowers are within EPA's recommended guidelines for risk (i.e., 1x10"6 to 1x10"4).

• The worst-case lifetime carcinogenic rates for combined feasible exposures are

within EPA's recommended risk range.

• Reasonable and worst-case estimates of potential risk for each hypotheticalgroundwater scenario, except for Scenario G (use of groundwater from wells in

the hexavalent chromium area) exceeded the upper bound of EPA's risk range(IxlO-4)

• Noncarcinogenic hazard indices were calculated for each age group for thegroundwater, air, and soil exposures; and for adults and children ages 6 to 12 onlyfor surface water and sediment exposures. Hazard indices for Scenario A (the

WMWA production well field discharge), soils, air, and Lycoming Creekexposures were below EPA's hazard index guideline of one. Thus, exposure to

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noncarcinogenic compounds through these pathways was not anticipated to resultin adverse health effects under the defined conditions of exposure.

• The noncarcinogenic hazard indices calculated for each hypothetical groundwaterscenario exceeded EPA's hazard index guideline of one. These exceedances

indicated that potential adverse health effects might occur if untreatedgroundwater in these areas was used as potable water. However, the likelihood ofuntreated groundwater consumption is low because (1) potable water is supplied

by WMWA and (2) the review of available well records and discussions withj,,, *

WMWA, long-time residents, and plant employees did not indicate the existence ofprivate users. As a result of a well survey, AVCO determined that there are no

individuals using groundwater as potable water.

• The compound responsible for the hazard index exceedances for the groundwater

scenarios was primarily DCE with lesser contributions from barium, manganese,lead, and cadmium. The inorganic results were based on total metals analysisrather than dissolved phase metals, yielding extremely conservative hazard indices.

• Of the various exposure scenarios evaluated, inhalation and ingestion of untreatedgroundwater were responsible for exceeding EPA's recommended carcinogenic

risk range (i.e., IxlO^to IxlO"4).

1.2.4 Post ROD Activities

In 1994, during the delay in receiving the NPDES limits, AVCO had the opportunity

to evaluate alternate remedies which are suitable to the site, more effective at cleanup, and

allow for less impact of contaminants to human health and the environment in comparison topump and treat. AVCO informed the EPA of the evaluation of alternative remedies in

December 1994 and presented a proposal for an alternative remedy to the EPA in May 1995.

Geraghty & Miller was retained by AVCO and evaluated and recommended to AVCO

an alternative remedy that included AS/SVE in-situ technologies to address VOCs ingroundwater and in-situ metals precipitation to address metals in groundwater at the site. The

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pilot test for AS/SVE was performed in October 1995 and the test results were submitted to

the EPA in a report dated April 1996. A six-month pilot test for in-situ metals precipitationwas performed from November 1995 through May 1996 and the test results were submitted

t o t h e E P A i n a report dated June 1996, ' . . ' ' '

As a result of the in-situ metals precipitation technology employed during the six-

month pilot test, concentrations of hexavalent chromium decreased to below the detection

levels. Concentrations of total chromium in filtered samples also generally decreased. In

addition, samples adjusted for pH indicated a decrease in total and dissolved chromium with

an increase in pH from 5 to 7. The AS/SVE pilot tests demonstrated that the air sparging/soilvapor extraction combination is applicable to the site and more effective than conventional

groundwater pump and treat.

Following a review of the data collected during the AS/SVE and in-situ metals

precipitation pilot tests, the EPA requested a FFS to support an amendment to the ROD.

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2. IDENTIFICATION AND SCREENING OF REMEDIAL TECHNOLOGIES

In this section, ARARs, the remedial action objectives (RAOs), and the general response

actions (GRAs) to accomplish those objectives are defined. The selected remedy and thealternate technologies available to achieve the RAOs are described.

2.1 APPLICABLE OR RELEVANT AND APPROPRIATE REQUIREMENTS

^(ARARS) ANI} OTHER CRITERIA

ARARs are used to 1) determine the appropriate cleanup goals, 2) define the scope andformulate remedial action alternatives, and 3) govern the implementation and operation of the

selected action. Section 121(d) of the Superfund Amendment and Reauthorization Act (SARA),

and the National Contingency Plan (NCP) require that remedial actions under the ComprehensiveEnvironmental Response, Compensations, and Liability Act (CERCLA) comply with all federal

ARARs. State requirements must also be attained under Section 121(d)(2)(c) of SARA, if theyare legally enforceable and consistently enforced statewide. Under Section 121(d)(4) of SARA,requirements may be waived by EPA under specific conditions, provided that protection of

human health and the environment is still assured.

2.1.1 Definitions of ARARs and Other Criteria

2.1.1.1 ARARs

ARARS may include the following:

• any standard, requirement, criterion, or limitation promulgated under federal

environmental law, and• any promulgated standard, requirement, criterion, or limitation under a state

environmental or facility-siting law that is more stringent than the associated federalstandard, requirement, criterion, or limitation.

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A requirement may be either "applicable" or "relevant and appropriate" to a site-specific

remedial action. "Applicable" requirements are promulgated cleanup standards, standards of

control, or other substantive environmental, criteria, or limitations that are generally enforceableunder federal or state law. These requirements specifically address a hazardous substance, a

remedial action, a location, or other site-specific condition.

"Relevant and appropriate" requirements are federal and state standards, criteria, or

limitations that are not legally applicable to the project, but which address problems sufficientlysimilar to those found.

2.1.1.2 To-Be-Considered (TBC) Materials

"To-Be-Considered" materials are advisories or guidance issued by the federal or state

government (e.g., reference doses) that are not generally enforceable and do not have the status of-

potential ARARs. However, where specific ARARs are not available, guidance documents oradvisories may be considered in determining the necessary level of cleanup for protection of

human health and the environment.

2.1.2 Identification of Potential ARARs and TBCs

To be consistent with NCP and SARA requirements, the following four categories wereconsidered during identification of potential ARARs and TBCs for AVCO Lycoming:

• federal requirements - applicable, or potentially relevant and appropriate;

• Pennsylvania state requirements - applicable, or potentially relevant and appropriate;

• federal criteria, advisories, and guidance documents to be considered (TBCs); and

• Pennsylvania state criteria, advisories, and guidance to be considered (TBCs).


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In the following subsections, potential ARARs and TBCs are identified and discussed. Inaccordance with the EP A FS guidance, the following three functional groups of potential ARARs

and TBCs have been evaluated:

• chemical-specific ARARS/TBCs (i.e., requirements that set protective cleanup levels

for the chemicals of concern, or indicate an acceptable limit of discharge associatedwith a remedial action);

• location-specific ARARs/TBCs (i.e., requirements that restrict remedial actions based

on the characteristics of the site or its immediate environment); and

• action-specific ARARs/TBCs (i.e., requirements that set controls or restrictions on

the design, implementation, and performance levels of activities related to themanagement of hazardous wastes or contaminants).

The media of concern for the AVCO Lycoming site is groundwater. As such, only

ARARs associated with groundwater remediation are discussed.

2.1.2.1 Potential Chemical-Specific ARARs and TBCs

Groundwater

Organic compounds and metals are present in the groundwater at greater-than-laboratorymethod detection limits. Some of these compounds are regulated hi potential water supplies

(under 40 CFR 141.11, 40 CFR 141.12, or 40 CFR 141.61), by the federal Maximum

Contaminant Levels (MCLs), which are ARARs. For organics and metals not addressed byARARs, TBCs were determined by the previous FS. TBCs for the AVCO Lycoming site include

proposed MCLs, secondary MCLs, or risk calculations of acceptable concentrations.

For risk-based criteria, carcinogenic potency factors or reference doses were used duringthe previous FS to calculate acceptable groundwater concentrations, on the basis of children ages6 to 12 consuming 2 liters of water per day. The potential cleanup levels for volatile organics and


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metals in groundwater are given in Table 2-1 . This table was provided in the previous FS and is asummary of potential ARARs applicable at the time of issuance of the ROD.

In addition to the above, environmental remediation standards established under thePennsylvania Land Recycling and Environmental Remediation Standards Act (Act 2) are ARARsand should be considered with regard to cleanup levels. Although Act 2 was effective July 18,

1995, the environmental remediation standards established by Act 2 are proposed and will not bepromulgated until 1998^ Given their proposed status, the current proposed standards establishedunder Act 2 are potential ARARs for this site.

2.1.2.2 Potential Location-Specific ARARs/TBCs

The southern half of the site is located in the 500-year floodplain; however, no portion ofthe plant is situated in the 100-year floodplain. The study area is not a critical habitat upon whichendangered or threatened species depend, nor is it located in a wilderness area or wildlife refuge, -

in or adjacent to a wetlands, within an area affecting a national wild, scenic or recreational river,or near any significant archaeological or historical sites.

2.1.2.3 Potential Action-Specific ARARs/TBCs

A number of potential action-specific ARARs have been identified for the selected

remedial alternatives, as discussed below.

Air Emissions

The PADEP requires that any new air contamination source not exempt under 25 PA

Code Section 127.14 be controlled to the maximum extent and consistent with the best availabletechnology (25 PA Code Section 127.1). Exemptions from control requirements may be granted

if it can be demonstrated that such controls are either economically or technically infeasible due tothe proposed source's unique characteristics and the project would not cause air pollution.Residual emissions from temporary remediation projects with adequate air pollution control are

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generally small enough or of such short duration that the projects can be considered sources ofminor significance and may be granted exemptions pursuant to minor significance provisions of 25PA Code 127.14 (8).

Underground Injection Control

The regulatory framework governing subsurface fluid distribution systems is established bythe EPA Underground Injection Control (UIC) Program. The regulations for the EPA UIC

Program are set forth in the Federal Register 40 C.F.R. Part 144 and the UIC Program ispromulgated under Part C of the Safe Drinking Water Act (SDWA). The UIC regulations define

and establish five classes of injection wells. Generally, Class V wells are shallow discharge ordisposal wells, stormwater or agricultural drainage systems, or other devices that are used torelease fluids into or above an underground source of drinking water (USDW). In Pennsylvania,

the EPA Region III has primacy in matters involving UIC and the PADEP defers to EPA inimplementing the UIC program. Regulations set forth under the Federal UIC Program andmandated by the SDWA and water quality permit regulations under the Pennsylvania Clean

Streams Law are action-specific ARARs.

2.1.3 Media of Concern

The media of concern under OU-1 is on-site groundwater. Off-site groundwater will be

addressed under a separate operable unit. During the previous FS for the site, the on-site

groundwater was subdivided into three areas to enable definition of the need for remedialmeasures in each area. These groundwater subdivisions are as follows:

• on-site overburden aquifer - Western Plant Area;

• on-site overburden aquifer - Central and Eastern Plant Area; and

• on-site bedrock aquifer.


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For the western plant area, three organics and two metals exceed applicable ARARs(MCLs); an additional six metals exceed applicable TBCs for groundwater. Organic constituentsexceeding MCLs are DCE (maximum only), TCE, and vinyl chloride. The inorganics that exceed

ARARs are cadmium and total and hexavalent chromium. TBCs are exceeded by the inorganicsaluminum, beryllium, copper, iron, manganese, and nickel. Based on site background data, it

appears that the aluminum, iron, and manganese are naturally occurring, rather than site related.

In the central and eastern plant area, five volatile organics exceed ARARs; and threeig-, *metals exceed TBCs for groundwater. TCE, 1,1-dichloroethene, 1,1,1-trichloroethane, and vinylchloride exceed ARARs. DCE in this portion of the overburden exceeds the MCL to be effective

30 July 1992. Chromium at maximum levels exceeds the current MCL, although the average

concentration of chromium in this area does not. Maximum chromium levels are below the MCLfor chromium that becomes effective on 30 July 1992. TBCs are exceeded only for aluminum,

iron, and manganese. None of these latter metals is site related, based on backgroundconcentration data.

For the on-site bedrock, four volatile organics and three inorganics exceed ARARs; three

metals and one semivolatile compound exceed TBCs for groundwater. DCE in this portion of the

overburden exceeds the MCL to be effective 30 July 1992. TCE, 1,1-dichloroethene, and vinylchloride exceed current ARARs. No semivolatile organics exceed ARARS in this portion of thegroundwater; however, a TBC for bis(2-ethylhexyl)phthalate is exceeded.

2.2 REMEDIAL ACTION OBJECTIVES

Remedial action objectives (RAOs) are statements that specify site remediation goals andidentify which COC, media, and exposure pathway will be addressed by remedial actions.

Remedial goals establish exposure levels that are protective of human health and the environment.

The RAOs are used in the screening of technologies and in the development and detailedevaluation of remedial alternatives.


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Based on the results of the RI, the nature and extent of contamination, and the riskassessment, the following RAOs were established for the site as part of the FS:

• Contamination will be mitigated such that ARARs are met in the overburden andbedrock aquifers to the extent practicable.

• Off-site movement of contaminated groundwater from either the bedrock or

overburden aquifers on-site will be prevented to the extent possible.

2.3 GENERAL RESPONSE ACTIONS

Remedial technologies are categorized in terms of General response Actions (GRAs).

GRAs are broad categories of remedial actions capable of addressing the contamination at the

site. GRAs describe, in general terms, these site-specific remedial actions that will satisfy theRAOs. The GRAs identified are as follows:

• Containment: This measure restricts migration of on-site contaminatedgroundwater past site boundaries.

• Removal: This action entails collection of groundwater for treatment or disposal,which can, by its nature, achieve a high degree of groundwater containment.

• Treatment: This category consists of biological or physical/chemical treatment of

groundwater above ground or in-situ.

• Disposal: Options discussed under disposal include off-site discharge of treated

groundwater.

2.4 SCREENING OF REMEDIAL TECHNOLOGIES AND PROCESS OPTIONS

The term remedial technologies refers to categories of remedial action that comprise

. subsets of the GRAs, such as groundwater pumping and aboveground treatment. Process optionsrefer to specific processes within the technology type (e.g., air stripping to treat groundwater).

The purpose of this section is to evaluate and select the GRAs, remedial technologies, and

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process options that are applicable for the site remedial action. Table 2-2 presents the identifiedtechnology types and process options for the on-site groundwater remediation.

The technologies and process options are evaluated based on effectiveness,implementability, and relative cost. The criteria are defined as follows:

Effectiveness focuses on three factors:

""""• the ability of process options to handle estimated volumes of groundwater and for

meeting the remedial action objectives; :

• the likely impacts to human health and the environment during the construction and

implementation phase of remediation; and

• the proven performance and reliability of the technology for remediating the medium

of concern under existing site conditions.

Implementability encompasses both the technical and administrative feasibility of

implementing the technology process option. Emphasis is placed on the following:

• the ability to obtain necessary permits for any off-site actions;

• the availability (including capacity) of treatment, storage, and disposal services where

applicable; and

• the availability of necessary equipment and skilled workers to implement the

technology.

Costs, at this stage, are developed on a relative and quantitative basis as "low","moderate", or "high". Detailed cost estimates are not generated for each technology. Relative

capital and operation and maintenance (O&M) costs, based on engineering judgment, are used tocompare the technology process options with the same technology type. The cost criterion plays

only a limited role in the screening of technologies at this stage of the FFS.

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The technologies were used to develop remedial alternatives for the remedial action at thesite. Assembled remedial alternatives are then subject to a detailed qualitative and quantitative

evaluation. Each alternative is evaluated on the basis of overall protection of human health andthe environment; compliance with ARARs; long-term effectiveness and performance; reduction of

toxicity, mobility, or volume; short-term effectiveness; implementability; cost; support agency

acceptance; and community acceptance. Alternatives are then compared to select the mostenvironmentally sound and cost-effective remedial action for the site.

""""Process descriptions for the components of the two remedial alternatives (groundwaterpump and treat and AS/SVE and in-situ metals precipitation) are provided below, along with an

evaluation of the processes in terms of effectiveness, implementability, and cost. The evaluation

of effectiveness, implementability, and cost is summarized in Table 2-3.

2.4.1 Alternative 1; Groundwater Recovery, Chemical Treatment for Metals, Air

Stripping. Emissions Controls, and Discharge of Treated Water

The processes associated with Alternative 1 are described below. A process flow diagram

is presented as Figure 2-1.

2.4.1.1 Recovery Wells

Construction of recovery wells involves drilling the well holes, installing the casing,grouting and sealing the annular space, installing well screens, fittings, graded filter material, andgravel pack, installing pump systems, and developing the wells. For groundwater removal, the

wells would be used for pumping of contaminated groundwater from the overburden and bedrockaquifers.

Recovery wells are the standard technology for long-term groundwater collection and thegroundwater recovery technology is expected to be reliable. Recovered water will requiretreatment before on or offVsite discharge. Possible modes of failure include well failure, pump

failure, and power failure. Well failure can occur through the clogging of gravel packs or the

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breakage or blocking of well screens. Capital costs associated with recovery wells are consideredmoderate. O&M costs are considered low to moderate.

2.4.1.2 Chemical Precipitation

Once the groundwater is recovered, the metals and solids in the groundwater must be

removed via groundwater treatment. A chemical precipitant such as a metal hydroxide or sulfideis added to the water. The chemical precipitation process is typically associated withflocculation/coagulation., neutralization, and filtration processes. Because the process results in

the formation of insoluble metal salts, sludge is generated that must be dewatered if land disposalof the sludge is planned.

Chemical precipitation is an effective and reliable conventional technology for metals

removal. The process is limited by the fact that not all metals have common optimium pH atwhich they precipitate. Chelating and complexing agents can interfere with the precipitation

process, but laboratory-scale testing can be used to optimize the full-scale process.

A significant limiting factor for chemical precipitation is the availability of a wastewater

treatment plant. The existing on-site treatment plant will not be available, so a new treatmentplant would have to be constructed. In addition, sludge generated in this process would require

proper handling and disposal.

Compared to the Alternative 2 processes, both capital and O&M costs associated withchemical precipitation would be high.

2.4.1.3 Air Stripping

Air stripping to remove organics from water is performed by passing air through VOC-

contaminated water in a packed column to facilitate the transfer of VOCs to off gas. The off gascan then be treated via fume incineration or vapor phase carbon.

Air stripping is not suitable for highly water-soluble organic compounds, metals, or non-volatile organics. However, the technology is expected to be effective for the primary VOCs

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detected in groundwater at the site (TCE, DCE, and vinyl chloride). Past experience at the sitehas indicated that stripper fouling due to mineral deposition and microbial growth is a significant

problem. Pretreatment to reduce available iron, manganese, and bacterial levels would berequired to maximize the effectiveness of air stripping.

The cost to install the stripper would be low, but overall system costs would be moderatedue to air emissions controls.

2.4.1.4 Fume Incineration

Fume incinerators are used to treat gaseous waste streams (i.e., air stripper off-gas)containing organics by converting the organic vapors to carbon dioxide and water and, for

chlorinated materials, hydrochloric acid. Fume incinerators operate at temperatures of up to 1600to 1800 degrees Fahrenheit. There are no by-products in the off-gas from this operation.

Exhaust gas scrubbing would be required if the feed contains high levels of organics, chlorides,

particulates, or acidic and/or metallic fumes. Scrubbing is not expected to be required for stripper-emissions from on-site groundwater treatment.

Fume incineration can provide efficiencies as high as 99 percent. Capital and O&M costsare moderate to high.

2.4.1.5 Vapor Phase Carbon Adsorption

Vapor phase carbon treatment can also be employed for treating off-gas. Contaminated

air flows through carbon beds and organics adsorb onto the carbon. The carbon is then either

regenerated or replaced. Vapor phase carbon systems are readily available and are easily installed.Costs are moderate to high, depending on carbon use requirements.

2.4.1.6 Stream Discharge

In this disposal option, groundwater treated to NPDES standards would be directly

discharged to the Oliver Street storm sewer, which flows to Lycoming Creek. Direct streamdischarge is a proven, effective means of disposing treated groundwater. All substantive

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requirements of a NPDES permit must be met. Periodic inspection and maintenance of thepipeline would be required. Costs are expected to be low.

2.4.2 Alternative 2; Air Sparging/Soil Vapor Extraction and In-Situ Metals Precipitation

The processes associated with Alternative 2 are described below. A schematic diagram ofthe AS/SVE process is provided as Figure 2-2.

2.4.2.1 Air Sparging/Soil Vapor Extraction-m^ « , .

Air sparging combined with soil vapor extraction is an in-situ technology used for the

treatment of VOCs dissolved in groundwater, adsorbed to saturated-zone soils, and trapped insoil pores in the saturated zone. Compressed air is injected through air sparging wells that are

screened in the saturated zone. The injected air travels upward in channels, creating turbulencethat causes an increase in desorption of the VOCs from the soil and volatilizes the VOCs ingroundwater (transfers the VOCs from the water phase to the air phase). After injection, the air,

which contains the volatilized contaminants, moves upward into the unsaturated zone where it canbe captured and removed using an SVE system. Typically, air sparging wells with overlapping

zones of influence are installed. Groundwater passing through the zone of influence will have

volatile contaminants stripped from the water.

This technology is proven to be effective and pilot tests performed at the site demonstrate

that this technology is applicable to this site. Compared to Alternative 1, costs are low.

2.4.2.2 In-Well Air Sparging

In-well air sparging is an in-situ remedial technology that employs stripping to removeVOCs from groundwater. The technology is used to remediate groundwater in fractured bedrock

or other locations where is it undesirable to apply the conventional form of air sparging. In-wellair sparging is accomplished by means of an air lift pump, as shown on the Figure 2-3. Waterenters the well through the bottom screen and is air lifted to the upper portion of the well through

an internal casing. As the water overflows the internal casing, it exits the well through the upperscreen and flows into the vadose zone. The in-well sparging is engineered so that as the water is


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air lifted, the VOCs are stripped. With an appropriate air to water mixture, a stripping efficiencyto meet groundwater cleanup requirements can be achieved, therefore, the water being reinjected

into the upper layer can be stripped of VOCs.

The effectiveness of in-well air sparging is dependent on the infiltration rate of the water

table aquifer, where air-lifted water is released after treatment. Pumping rates can be modified toensure infiltration of the treated water, without compromising stripping efficiencies. Aremovable filter can be used to prevent iron and manganese precipitates from entering and

fouling the reinjection zone, and further limiting the rate of flow to the upper aquifer.

During implementation of the AS/SVE remedy for the overburden, the bedrock will be

monitored for improvements in water quality due to natural attenuation or as a result of AS/SVEin the overburden. The need for bedrock aquifer remediation, such as in-well air sparging

technologies, will be evaluated at the appropriate time.

2.4.2.3 Metals Precipitation

Chromium

In-situ precipitation of chromium is based on the microbial reduction of hexavalentchromium Cr(VI) to trivalent chromium Cr(III) (i.e., the oxidation state of the chromium ischanged from Cr+6 to Cr+3). The reduction process yields significant remedial benefits because

trivalent chromium Cr(III) is less toxic, less mobile, and precipitates from solution more readilythan hexavalent chromium Cr(VI). The reduced trivalent chromium will precipitate as chromiumhydroxide.

To promote the in-situ microbial reduction of hexavalent chromium Cr(VI) to trivalent

chromium Cr(III), a dilute molasses solution (which contains readily degradable carbohydrates)is injected into the impacted aquifer via a series of injection wells. The carbohydrates, whichconsist mostly of sucrose, are degraded by the indigenous heterotrophic microorganisms present

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in the aquifer. This metabolic degradation process utilizes the available dissolved oxygen

contained in the groundwater.

Depletion of the available oxygen present in the groundwater causes reducing conditions

to develop. As a result, the hexavalent chromium Cr(VI) is reduced to trivalent chromiumCr(III). The trivalent chromium Cr(III) then reacts with available hydroxide ions to form

chromic hydroxide [Cr(OH)3](s) precipitates. These precipitates are then retained by the soil

particles within the aqujfer.

A six-month pilot test performed at the site demonstrated that in-situ metals precipitation

is an effective technology for the reduction of chromium and that the technology is applicable tothe site. Compared to Alternative 1, costs associated with in-situ metal precipitation are low.

Heavy Metals

Precipitation as sulfides is considered the dominant mechanism removing dissolved"heavy metals from the groundwater, including cadmium. This technology requires a source of

carbon to support microbial growth, a source of sulfate, and a population of sulfate reducing

bacteria. The molasses solution will provide the source of carbon and sulfate. Sulfate reducing

bacteria are normally present under natural conditions; however, in some stressed environments,

the sulfate reducing bacteria may not be present. The pilot test performed at the sitedemonstrated that a population of sulfate reducing bacteria may not be currently present. To

overcome the lack of naturally occurring sulfate reducing bacteria, alternate sources of sulfatereducing microorganisms can be introduced into the aquifer. Alternate sources include: 1)

filtered supernatant from an anaerobic digester and 2) sulfate reducing bacteria which are

artificially cultured expressly for that purpose. Additionally, sulfide can be introduced into theaquifer in the form of sodium sulfide or calcium sulfide. Precipitated metallic sulfides will be

filtered out by the soil matrix in the aquifer.


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2.4.2.4 Vapor-Phase Carbon Adsorption

Vapor phase carbon treatment will be employed for treating off-gas from the soil vaporextraction process. Contaminated air flows through carbon beds and organics adsorb onto the

carbon. The carbon is then either regenerated or replaced. Vapor phase carbon systems arereadily available and are easily installed. Costs are moderate to high, depending on carbon use

requirements.

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3. DEVELOPMENT OF REMEDIAL ALTERNATIVES

The purpose of the FFS is to compare and evaluate the remedy selected by the 1991

ROD with the alternate in-situ remedy. In the previous sections of this FFS, general response

actions and the related remedial technologies and process options associated with the selected

remedy and the alternate technologies were identified. In this section, the remedial

technologies and process options that were retained are combined into remedial action

alternatives.«v-

3.1 REMEDIAL ACTION ALTERNATIVES

The remedial action alternatives selected for evaluation for the remediation of the on-site groundwater are as follows:

Alternative 1: Groundwater Recovery, Chemical Treatment for Metals, Air

Stripping, Emissions Controls, and Discharge of Treated Water.

Alternative 2: Air Sparging/Soil Vapor Extraction and In-Situ Metals

Precipitation.

3.1.1 Aternative 1; Groundwater Recovery. Chemical Treatment for Metals. AirStripping. Emissions Controls, and Discharge of Treated Water

This alternative consists of the following, as summarized in the previous FS (ERM,

1991):

• a recovery well system to contain groundwater on-site and to collect contaminatedgroundwater;

• aboveground chemical treatment for the portion of the groundwater flowcontaining elevated levels of chromium and other metals;


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• air stripping for organics removal from the entire recovered groundwater flow

stream;

• fume incineration or vapor phase carbon for treatment of off-gas from the airstripper; and

• direct discharge of the treated effluent to Lycoming Creek or the Oliver Street

storm sewer.

^ The recovered groundwater (pumped at 66 gpm) from the western portion of the sitewould be piped to a dedicated on-site treatment facility and treated to reduce chromium and

subsequently precipitate it and other metals. This stream would then be combined with the

remainder of the groundwater (177 gpm) to be treated from the eastern and central portion of

the plant (both overburden and bedrock) and be pumped to an air stripper (at a combined rateof approximately 243 gpm), where VOCs would be removed to required levels. The

conceptual locations of recovery wells are shown on Figure 3-1.

The metals treatment facility would consist of a modular chromium reduction and

chemical precipitation system (coagulation, flocculation, and settling) for metals precipitationand the existing on-site WWTP plate and frame filter process for solids dewatering. An iron

co-precipitation process would be used for chromium reduction and dissolved metals

removal, using ferrous sulfate and polymer, at a pH of 9. It is assumed that the sulfuric acidand caustic (used for pH adjustment) and ferrous sulfate will be stored and fed from the

indoor tanks for the existing system. The sludge produced by the system will be dewateredand is estimated to contain 30 percent solids after dewatering.

The air stripping system would include feed pumps, a particle pre-filtration system, ablower (1,300 cfrn), and a 4-foot diameter packed tower with a 20-foot packed depth

operating an air-to-water ratio of 40:1.


3-3

The off-gas from the air stripper would then be treated with vapor phase carbon or

with a fume incinerator to destroy VOCs. The incinerator is sized for 1,300 cfm of flow and

includes a heat exchanger to minimize O&M costs.

The effluent from the air stripper would be discharged to the Oliver Street stormsewer and thereafter to Lycoming Creek. Effluent limitations would be determined through

coordination with PADEP. This overall treatment system would operate until either the

groundwater cleanup ARARs were achieved or practical limits of contaminant recovery werereached.

3.1.2 Alternative 2: Air Sparging/Soil Vapor Extraction and In-Situ MetalsPrecipitation

Alternative 2 consists of AS/SVE and in-situ metals precipitation. Air spargingcombined with soil vapor extraction will be used for the remediation of VOC-contaminated

groundwater at the site. In-situ metals precipitation will be used for the remediation ofchromium-contaminated groundwater.

The AS/SVE technology results in mass removal from the overburden aquifer, apotential source of volatile constituents in the bedrock aquifer. During implementation of the

AS/SVE remedy for the overburden, the bedrock will be monitored for improvements inwater quality due to natural attenuation or as a result of AS/SVE in the overburden. The needfor bedrock aquifer remediation, such as in-well air sparging technologies, will be evaluated

at the appropriate time.

In October 1995, AS/SVE pilot tests were performed in three areas of the site. Theresults of the pilot test demonstrate that AS/SVE is a viable remedial alternative for in-situtreatment of VOCs in groundwater at the site and that VOC concentrations in the extracted

soil gas increased as a result of air sparging. Mass removal rates are dependent on the

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existing concentrations of VOCs in groundwater within the effective radius of influence of

the system and the rate of replenishment resulting from groundwater migration.

During the pilot test, information necessary to design a full-scale AS/S VE system was

collected. The components of the full-scale AS/SVE system will include the following:

• a series of air sparging and soil vapor extraction wells along the perimeter of the

-^ site; m

• air compressors, blowers, and associated piping and equipment

• vapor-phase carbon for off-gas treatment

In-situ precipitation of chromium will be used to remediate and contain chromium-

contaminated groundwater in the western portion of the site.

A six-month in-situ metals precipitation pilot test was performed in the westernportion of the site from November 1995 through May 1996. The results of the pilot testdemonstrated the following:

• Reducing conditions, as evidenced by redox and dissolved oxygen measurements,and a significant decrease in hexavalent chromium concentrations hi groundwater,

as evidenced by the HACK field test kit, were observed in the injection wellswithin 9 days after molasses injection.

• Laboratory analytical results indicate a decrease in hexavalent chromium from 2.4

mg/L to less than 0.01 mg/L in MW-3R, located approximately 5 feet from theinjection wells, within approximately 70 days. In the southern area, laboratoryanalytical results indicate a decrease in hexavalent chromium from approximately3 mg/L to less than 0.01 mg/L in MW-18, located approximately 12 feet from theinjection wells, within approximately 155 days.


3-5

• The concentration of hexavalent chromium in the groundwater decreased to below

detection levels during the six-month field design test as a result of molassesinjection. In general, the concentration of total chromium also decreased during

the test.

• In-situ metals precipitation is a viable remedial alternative for in-situ treatment ofdissolved hexavalent chromium in groundwater at the site.

^ During the .pilot test, information necessary to design a full-scale in-situ metals

precipitation system was collected. The components of the full-scale in-situ metals

precipitation system will include the following:

• a series of molasses injection wells;

• mixing tanks for molasses solution;• pumps, piping, and associated equipment for molasses injection; and

• a programmable logic controller (PLC) to automatically control the amount of

solution injected.

: A R 3 0 0 I 7 SGERAGHTY & MILLER, INC.

4. DETAILED ANALYSIS OF REMEDIAL ALTERNATIVES

In this section of the FFS, the remedial alternatives described in the previous section

are analyzed to determine the effectiveness of each alternative in achieving the RAOs at the

site.

4.1 EVALUATION OF REMEDIAL ALTERNATIVES

Tn^ *

The remedial alternatives are evaluated to determine the effectiveness of each

alternative in addressing the impacts to human health and the environment attributed to theCOCs at the site. Each alternative is evaluated based on the following evaluation criteria:

• Overall protection of human health and the environment• Compliance with Applicable or Relevant and Appropriate Requirements

(ARARs)

• Long-term effectiveness and permanence

• Short-term effectiveness

• Reduction of toxicity, mobility, or volume• Implementability

• Cost

• Support agency acceptance• Community acceptance

The first two criteria are referred to as threshold criteria. The next five criteria arecommonly referred to as primary balancing criteria. These seven criteria are further

described in this section and make up the major portion of the evaluation.

The last two criteria are commonly referred to as a modifying criterion. These criteriawill be evaluated following completion of the FFS and public review and comment.

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4.1.1 Overall Protection of Human Health and the Environment

This evaluation criterion is used to assess whether each alternative is protective of

human health and the environment. The overall assessment of protection is based on acomposite of factors assessed under other evaluation criteria, especially long-term

effectiveness and performances, short-term effectiveness, and compliance with ARARs.

4.1.2 Compliance with ARARs

This evaluation criterion is used to determine how each alternative complies with

ARARs.

4.1.3 Long-Term Effectiveness and Permanence

This evaluation criterion addresses the results of a remedial action in terms of its"permanence and the quantity/nature of waste or residual levels of contamination remaining at

the Site after response objectives have been met. The primary focus of this evaluation is theextent and effectiveness of the controls that may be required to manage the residual levels of

COCs remaining at the site.

4.1.4 Reduction of Toxicitv, Mobility, or Volume

This evaluation criterion assesses the ability of the remedial alternative to permanently

and significantly reduce toxicity, mobility, or volume of the COCs.

4.1.5 Short-Term Effectiveness

This evaluation criterion assesses the effects of the alternative during the construction

and implementation phase until remedial response objectives are met. Under the criterion,


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alternatives are evaluated with respect to their effects on human health and the environmentduring implementation of the remedial action.

4.1.6 Implementability

This evaluation criterion addresses the technical and administrative feasibility ofimplementing an alternative and the availability of various services and materials requiredduring its implementation.

4.1.7 Cost

The capital and O&M cost estimates are derived for each alternative and used as abasis for comparison in the evaluation of alternatives. Detailed capital cost estimates and

O&M costs for each alternative are included in Appendix A.

4.1.7.1 Capital Costs

Capital costs consist of direct (construction) and indirect (non-construction and

overhead) costs. Direct costs include expenditures for the equipment, labor, and materialsnecessary to install remedial actions. Indirect costs include expenditures for engineering andother services that are not part of actual installation activities, but are required to complete the

installation of remedial alternatives.

4.1.7.2 Operation and Maintenance Costs

Annual O&M costs are post-construction costs necessary to ensure the continued

effectiveness of a remedial action. Such costs include occasional reevaluation of the siteduring and after remedial efforts have been taken. Although the schedule for reevaluation of a

site during and after remediation is determined on a case-by-case basis, for the purposes of


4-4

this study, it has been assumed that the source areas will be reevaluated every 5 years (worst-case scenario) until completion of the remediation.

4.1.7.3 Present-Worth Analysis

A present-worth analysis is used to evaluate expenditures that occur over different

time periods by discounting all future costs to a common base year, usually the current year.This procedure allots the cost of remedial action alternatives to be compared on the basis of• P. ;

a single figure representing the amount of money that, if invested in the base year and

disbursed as needed, would be sufficient to cover all costs associated with the remedial actionover its planned life. For this evaluation, a discount interest rate of 6 percent has been

assumed.

4.2 ANALYSIS OF REMEDIAL ALTERNATIVES

In this section, each alternative is analyzed in reference to the evaluation criteriadescribed previously.

4.2.1 Alternative 1: Groundwater Recovery. Chemical Treatment for Metals. Air

Stripping. Emissions Controls, and Discharge of Treated Water

4.2.1.1 Overall Protection of Human Health and the Environment

This alternative would be protective of human health over time as groundwatercontaining site-related compounds would not migrate off-site. Recovery and treatment of

groundwater at the southern plant boundary would permanently remove contaminants from

groundwater beneath the plant. The treatment system is expected to provide adequatetreatment to achieve ARARs for discharge. This alternative would reduce the concentrations

of site-related compounds in the groundwater beneath the plant; however, the ability to attainARARs in the two aquifers via long-term groundwater pumping is not known. A more


4-5

with current recovery efforts. Therefore, the current mass of contaminants leaving the plantproperty and the risk associated with these contaminants (assuming future hypothetical

groundwater use) will be minimized. This alternative could achieve the remedial actionobjectives over time via groundwater pumping and treatment.

4.2.1.2 Compliance with ARARs

Chemical-Specific ARARsmttr_ «

Chemical-specific ARARs for on-site overburden groundwater are currently exceededfor metals and VOCs in the western plant area and for VOCs in the central and eastern plant

area. The bedrock groundwater contains VOCs in excess of ARARs. These compounds will

be recovered and treated to the ARARs for direct or indirect discharge. Only beryllium mayexceed trace direct discharge levels, and it may be technically infeasible to meet this level

through treatment. Over time, as a result of groundwater recovery and treatment, the-concentrations of contaminants in the groundwater will decrease. While it is intended that

ARARs will be achieved in groundwater over time, the success of this remedial option atmeeting ARARs in the aquifer cannot be assured.

Contaminant-specific TBCs for site-related compounds (e.g. copper) are also expectedto be met with the treatment system proposed. Levels of naturally occurring metals(aluminum, barium, iron, manganese) may not meet TBCs.

Action-Specific ARARs

ARARs for air emissions from air stripping would be met via fume incineration. Thesubstantive requirement of NPDES effluent discharge limits for the Oliver Street storm sewer

and Lycoming Creek would have to be met.


4-6

4.2.1.3 Long-Term Effectiveness and Permanence

The magnitude of residual risk, once groundwater remediation has met ARARs oralternate levels approved by PADEP and EPA, should be within recommended guidelines.

It is expected that this alternative would be effective over the long term. Provision of

off-gas treatment would mitigate any residual risk from long-term exposure to emissions from

the new air stripper. Note that the potential risk from air emissions from currently operatingstrippers at the site is within recommended cancer risk guidelines. Emissions controls are

potentially required for the new stripper because the mass of VOCs to be treated is muchhigher than that presently being treated.

Sludges from the metals precipitation process will be dewatered for proper off-sitedisposal or possible metals reclamation. Filtered solids removed from the influent to the air

stripper would be combined with the sludge from metals precipitation. The recovery of-groundwater contaminants, the treatment of organics with air stripping, and metalsprecipitation are all permanent processes.

The duration of groundwater recovery and treatment cannot be determined given

existing information. For purposes of cost estimation, a 30-year remedial duration has beenassumed.

4.2.1.4 Reduction of Toxicity, Mobility, or Volume

Toxicity

Reduction of toxicity would not be achieved for VOCs through air stripping alone, as

the contaminants only undergo a transfer from the liquid to the gas phase in this process.

Fume incineration will result in high-efficiency destruction of the organic contaminants in theoff-gas. A reduction in toxicity would be achieved for chromium through its conversion from

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hexavalent to trivalent form. Precipitation of trivalent chromium and other metals (especiallycadmium) would further reduce toxicity due to metals.

Mobility

The mobility of contaminants would be controlled through implementation of thisalternative by containing the flow of on-site groundwater from the site.

^^ *

VOCs would not be released to the atmosphere during groundwater treatment via airstripping because fume incineration will be employed for off-gas treatment. Hexavalent

chromium reduction and metals precipitation both reduce the overall leachability of the metalsof concern.

Volume

The volume of groundwater contaminated would be reduced over time with JBk

implementation of this alternative as on-site groundwater is contained and the mass ofcontaminants (both organics and metals) is reduced.

4.2.1.5 Short-Term Effectiveness

Minimal potential risks to on-site workers and/or the community from VOC emissionscould occur during the construction of the recovery wells and during groundwater collectionsystem installation. Exposure to volatile releases would be minimized by the use of proper

operating procedures and any necessary protective gear for on-site workers. It is notexpected that these emissions would adversely affect nearby residents because any VOCs

released during well installation would be dispersed in the atmosphere and any releases wouldbe of short duration. Site work for treatment system installation will be in an area paved withconcrete. Soils beneath the pavement are not expected to be contaminated, therefore

disturbance of soil during foundation and piping installation should not cause significant risk.

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4.2.1.6 Implementability

Technical Feasibility

The recovery well system uses conventional construction technology, and the materialsand labor for its installation are readily available. Sufficient space is available to situate the

treatment system on plant property. The groundwater treatment technologies used are

commercially available processes that have proven reliable in numerous applications forgroundwater or process wastewater cleanup. Effluent limitations for direct discharge are

expected to be met. Future remedial measures are not restricted by implementation of thegroundwater recovery and treatment system. If needed, additional wells could be installed orpumping rates varied to optimize on-site groundwater containment. Because an extensive

groundwater monitoring program is already in place at the facility, the effect of an expandedpump-and-treat system on plume concentrations should be readily determinable. Flexibility in.

routing groundwater to either the chromium treatment or directly to organics treatment,depending on the metals content of water extracted from each well, is possible with therecovery well system as designed.

Administrative Feasibility

The substantive requirements of NPDES permitting have been determined incoordination with the PADEP.

Availability of Services and Materials

Permitted off-site disposal and sludge reclamation facilities are available for the sludgegenerated from metals precipitation. The materials, labor, equipment, and services required to

install and operate the recovery and treatment system are readily available. The system

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required to install and operate the recovery and treatment system are readily available. The

system components are all currently commercially marketed by multiple vendors, enablingcompetitive bidding.

Should the heavy metals sludge from chemical precipitation be hazardous accordingto the toxicity characteristic leading procedure (TCLP) and not suitable for reprocessing for

metals removal, RCRA-permitted hazardous waste facilities able to receive the sludge are

available.

4.2.1.7 Cost

The costs to implement this alternative are summarized as follows:

Capital Cost $2,900,000

O&M (annual) $517,500Present Worth $10,000,000

4.2.1.8 Supporting Agency and Community Acceptance

Supporting agency and community acceptance will be evaluated after a public hearing

on the FFS.

4.2.2 Alternative 2; Air Sparging/Soil Vapor Extraction and In-Situ Metals

Precipitation

4.2.2.1 Overall Protection of Human Health and the Environment

This alternative would be protective of human health over time as groundwater

containing site-related compounds would not move across the plant boundary. In-situ and

treatment of groundwater at the southern plant boundary would permanently removecontaminants from groundwater beneath the plant. The treatment system for air extracted


4-10

discharge. This alternative would reduce the concentrations of site-related compounds in thegroundwater beneath the plant; however, the ability to attain ARARs in the two aquifers is not

known. The current mass of contaminants leaving the plant property and the risk associatedwith these contaminants (assuming future hypothetical groundwater use) will be minimized.This alternative could achieve the remedial action objectives over time.

4.2.2.2 Compliance with ARARs

Chemical-Specific ARARs

Chemical-specific ARARs for on-site overburden groundwater are currently exceeded

for metals and VOCs in the western plant area and for VOCs in the central and eastern plantarea. The bedrock groundwater contains VOCs in excess of ARARs. The VOC compoundswill be recovered and treated to the ARARs for discharge to air. In the western portion of the

site, hexavalent chromium in groundwater will be reduced to trivalent chromium, which will-be precipitated as chromium hydroxide, thereby removing chromium from the groundwater.

Other metals (e.g., cadmium) may be removed from groundwater depending on the availability

of sulfate reducing microorganisms in the aquifer. Over time, as a result of AS/SVE and in-situ metals metals precipitation, the concentrations of contaminants in the groundwater will

decrease. While it is intended that ARARs will be achieved in groundwater over time, thesuccess of this remedial option at meeting ARARs in the aquifer cannot be assured. Levels of

naturally occurring metals (aluminum, barium, iron, manganese) may not meet TBCs.

Action-Specific ARARs

ARARs for air emissions would be met via vapor-phase carbon adsorption. Action-

specific ARARS for solution injection for the metals precipitation will be determined during

the remedial design phase of the project.

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4.2.2.3 Long-Term Effectiveness and Permanence

The magnitude of residual risk, once groundwater remediation has met ARARs or

alternate levels approved by PADEP and EPA, should be within recommended guidelines.

It is expected that this alternative would be effective over the long term. Provision of

off-gas treatment would mitigate any residual risk from long-term exposure to emissions fromthe SVE system.

The recovery of groundwater contaminants via AS/SVE, the treatment of thosecontaminants with vapor phase carbon adsorption, and off-site regeneration of vapor phase

carbon will permanently remove the treated contaminants from the site. The chromiumprecipitation process is also permanent and irreversible under the existing natural groundwaterconditions. The potential for re-dissolution of chromium exists if the groundwater pH fallsbelow a pH of 5. The pH of groundwater upgradient and downgradient of the site ranges,from 5.3 to 7.8.

The duration of AS/SVE and in-situ metals precipitation cannot be determined given

existing information. For purposes of cost estimation, a 10-year remedial duration has been

assumed.

4.2.2.4 Reduction of Toxicity, Mobility, or Volume

Toxicity

Reduction of toxicity would be achieved for VOCs through AS/SVE with off-gastreatment. Vapor phase carbon used for off-gas control would be regenerated off-site. VOCs

would be subsequently destroyed in the process of regeneration of the activated carbon. A

reduction in toxicity would be achieved for chromium through its conversion from hexavalentto trivalent form. Precipitation of trivalent chromium and other metals (especially cadmium)

would further reduce the toxicity due to metals.

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GERAGHTY & MILLER, INC.

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reduction in toxicity would be achieved for chromium through its conversion fromhexavalent to trivalent form. Precipitation of trivalent chromium and other metals (especially

cadmium) would further reduce the toxicity due to metals.

Mobility

The mobility of contaminants would be controlled through implementation of this

alternative by preventing the movement of untreated groundwater away from the site.

Release of VOCs to the atmosphere during AS/SVE system operation would be

controlled with carbon adsorption. Hexavalent chromium reduction and metals precipitationboth reduce the overall leachability of the metals of concern.

Volume

The volume of contaminated groundwater would be reduced over time with

implementation of this alternative as on-site groundwater is contained and the mass ofcontaminants (both organics and metals) is reduced.

4.2.2.5 Short-Term Effectiveness

Minimal potential risks to on-site workers and/or the community from VOC

emissions could occur during the construction of the wells and system installation. Exposureto volatile releases would be minimized by the use of proper operating procedures and any

necessary protective gear for on-site workers. It is not expected that these emissions would

adversely affect nearby residents, because any VOCs released during well installation wouldbe dispersed in the atmosphere and any releases would be of short duration. Site work for

treatment system installation will be in an area paved with concrete. Soils beneath thepavement are not expected to be contaminated; therefore, disturbance of soil duringfoundation and piping installation should not cause significant risk.


4-13

4.2.2.6 Implementability

Technical Feasibility

The alternate system uses conventional construction technology, and the materials

and labor for its installation are readily available. Sufficient space is available to situate the

treatment system on plant property. The off-gas treatment technologies used arecommercially available processes that have proven reliable in numerous applications for

«**- *

remediation. Air effluent limitations are expected to be met. Future remedial measures are

not restricted by implementation of this remedy. If needed, additional wells could beinstalled or AS/SVE and injection rates varied to optimize on-site groundwater treatment and

contaminant containment. Because an extensive groundwater monitoring program is already

in place at the facility, the effect of this alternative on plume concentrations should be readilydeterminable. Flexibility in operation of the system is possible with the system as designed.

Administrative Feasibility

Administrative procedures associated with air emissions controls and molassesinjection will be implemented.

Availability of Services and Materials

The materials, labor, equipment, and services required to install and operate theAS/SVE and metals precipitation system are readily available. The system components areall currently commercially marketed by multiple vendors, enabling competitive bidding.

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4.2.2.7 Cost

The costs to implement this alternative are summarized as follows:

Capital Cost $1,600,000

O&M (annual) $357,500

Present Worth $4,200,000

4^2.8 Supporting Agency and Community Acceptance

Supporting agency and community acceptance will be evaluated after a public hearingon the FFS.

R R 3 0 0 I 9 0OERAGHTY S MILLER, INC.

5. COMPARATIVE ANALYSIS OF ALTERNATIVES

This section describes the relative effectiveness of the two alternatives (groundwaterrecovery and above ground treatment vs. air sparging/soil vapor extraction and in-situ metals

precipitation) with respect to the evaluation criteria described previously. The alternativesare compared qualitatively, and substantive differences are identified between them.

5.1 OVERALL PROTECTION OF HUMAN HEALTH AND THE ENVIRONMENT^^ *

For overall protection of human health and the environment, no unacceptable risks are

associated with current groundwater use in the area, because of the treatment system at theWMWA well field. Alternatives 1 and 2 minimize off-site migration of contaminants ingroundwater flowing from the site.

5.2 COMPLIANCE WITH ARARS

Both alternatives can be designed and implemented with the objective of satisfyingthe ARARs. However, Alternative 2 may achieve compliance with ARARs more quickly

than Alternative 1.

5.3 LONG-TERM EFFECTIVENESS AND PERMANENCE

With respect to long-term effectiveness, both Alternatives 1 and 2 are expected to

provide a high degree of permanence. Alternative 2, however, may provide more long-termeffectiveness and permanence than Alternative 1 because the in-situ technologies address the

source of the contaminants (i.e., the soil), as well as contain the contaminated groundwaterfrom migrating off-site. Alternative 1 does not focus on remediation of the source of thecontaminants.

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5-2

The time to remediation for Alternative 1 is assumed to be 30 years, while the time toremediation for Alternative 2 is estimated to be less than 10 years. Alternative 2, therefore,

provides a higher degree of long-term effectiveness than Alternative 1.

5.4 SHORT-TERM EFFECTIVENESS

With respect to short-term effectiveness, there are minimal potential risks associated

with the construction of either alternative.-v- • ;

5.5 REDUCTION OF TOXICITY, MOBILITY, OR VOLUME

Alternative 2 is expected to provide the higher degree of toxicity, mobility, or volumereduction, because of the additional reduction in organics afforded by the removal of

contaminants from the saturated zone associated with the in-situ technologies. In addition, asignificant amount of contaminated waste would continually be generated by Alternative 1"

through the operation of the system, due to the need to treat recovered groundwater. The

amount of waste generated by Alternative 2 is insignificant compared to the amount that

would be generated by Alternative 1.

5.6 EMPLEMENTABELITY

Both Alternatives 1 and 2 are implementable. Although Alternative 2 includes

innovative technologies with associated uncertainties for O&M, the pilot tests performed at

the site demonstrate that the technologies are effective at remediation and applicable to thesite.

5.7 COSTS

Cost estimates were developed for each of the alternatives. The construction andO&M costs for each alternative were estimated conservatively.

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The details of the estimated cost are presented in Appendix A. The present worth of

costs associated with Alternative 1 was calculated using a discount rate of 6 percent for a30-year time period, while the costs associated with Alternative 2 assumed the same discountrate over a 10-year time period. The estimated present-worth cost for each of the alternatives

is as follows:



5.8 SUPPORTING AGENCY AND COMMUNITY ACCEPTANCE

The supporting agency and community acceptance will be evaluated after a publichearing on the FFS. Geraghty & Miller anticipates that both alternatives will be acceptable tothe supporting agency.

A R 3 0 0 I 9 3GERAGHTY & MILLER, INC. O

6. RECOMMENDED ALTERNATIVE

Following the analysis of the two potential remedial alternatives for the site, Geraghty& Miller recommends that Alternative 2 be implemented as the remedial action. Alternative

2 provides the best balance of the evaluation criteria.

Alternative 2 is protective of human health and the environment by ensuring that

current risks are eliminated in the future. This is accomplished by the removal of

contaminants from the groundwater through AS/S VE and in-situ metals precipitation.

This alternative will have a high degree of short-term effectiveness, as well as

providing long-term effectiveness and implementability with moderate cost. Alternative 2also reduces the toxicity, mobility, and volume of the contaminants in groundwater.

Geraghty & Miller anticipates that Alternative 2 will be acceptable to the supporting

agencies and the community based on the results of the pilot tests.

A R 3 0 0 I 9 1 4GERAGHTY & MILLER, INC.

7. REFERENCES

Environmental Resources Management, Inc., 1991. Draft Feasibility Study at Textron

Lycoming, Williamsport, Pennsylvania, March 15, 1991.

Environmental Resources Management, Inc., 1991. Draft Remedial Investigation Report forTextron Lycoming, Williamsport, Pennsylvania, January 15, 1991.

^^ *Environmental Resources Management, Inc., 1991. Draft Risk Assessment, Textron

Lycoming, Williamsport, Pennsylvania, January 31, 1991.

Geraghty & Miller, Inc., 1996a. Air Sparging and Soil Vapor Extraction, Field Design Test

Results, AVCO Lycoming Superfund Site, Williamsport, Pennsylvania, April 19,

1996.

Geraghty & Miller, Inc., 1996b. In-Siru Metals Precipitation, Field Design Test Results,

AVCO Lycoming Superfund Site, Williamsport, Pennsylvania, June 14, 1996.

U.S. Environmental Protection Agency, 1991. Record of Decision, AVCO Lycoming Site,

Williamsport, Pennsylvania, July 2,1991.


-1. i uu.ntially nppn cable ui «\xi£vant «muAVCO Lycoming Focused Feasibility Study.

d Cntmouu be Coiuiuc

Compound

VOLATILESBenzeneChloroformTolueneTrichloroethyleneVinyl chloride1 , 1 -Dichloroethane1,1-Dichloroethylene1,1,1 -Trichloroethane1,2-Dichloroethene (total)

SEMI-VOLATILES1 ,2-DichlorobenzeneBis(2-ethylhexyl) phthalatedelta BHCbetaBHCBenzoic acid

INORGANICSAluminumAntimonyArsenicBariumBerylliumCadmiumChromium (total)Chromium (hexavalent)CobaltCopperIronLeadManganeseMercuryNickelSeleniumSilverVanadiumZinc

AIRTBCs

PADEP Air ToxicsGuidelines (WM3)

12.54.35

76.96.12

120

0.024 (b)1.2(b)

0.01 (b)0.0556 (b)

0.00833 (b)

_ - - - - - -1.5 (b)24 (b)

0.24 (b)0.24 (b)

GROUNDWATERA"RA"RS

FederalMCLs(mg/1)

0.005•l(a)1 *

0.0050.002

0.0070.2

0.07 * (c)

0.06*

0.051

0.01/0.005 *0.05 */0.1 *0.05 */0.1 *

- - - - - •0.05

0.002-0.01/0.05 *

0.05

TBCs

Health Based Criteriaor lxlO(-6) CancerRisk Level (mg/1)

2

0.000177

0.1

Federal Proposed (P)and Secondary (S)

MCLs (rig/I)

0.04 (P,S)

*

0.01 (P,S)0.004 (P)

0.05-0.2 * (S)0.01-0.005 (P)

2(P)0.001 (P)

120

1.3(P)/1.0(S)0.3(S)

0.005 (P)0.05 (S)

0.1 (P)

0.1 (S) *

5.0(S)

SURFACE WATERARARs

PADEPWater Quality

Criteria** (mg/1)

0.0010.00020.3300.003

0.00002

0.000060.6050.350

0^1640.909

0.00002

0.1450.05

0.0000070.00110.2210.0110.3960.012

0.0032

0.0000120:160

0.0050.00020.1030.110

COoCD

UDcr>

Notes;(a) Total THMs.(b) Not applicable to dissolved metals in aqueous stream.(c) More stringent cis- standard used.(P) Proposed.(S) Secondary.* Effective in 1992.** Most stringent of human health and aquatic life standards.* Based on total chromium. GERAGHTY & MILLER, INC.

APPLIC.XLS

of2

Table 2-2. Identification of Focused Feasible Technology Types and Process Options for On-site Groundwater,AVCO Lycoming Superfund Site, Williamsport, Pennsylvania.

GeneralResponse Action

TechnologyType

ProcessOption Description

ScreeningComments

Containment In-Situ ReactiveZones or Curtains

Air Sparging/Soil Vapor Extraction

Employment of a series of wells toremediate/contain migration of contaminantsin groundwater; compressed air is injectedand strips organic compounds;VOC-containing air is captured by SVEsystem; air sparge wells have overlappingzones of influence

Retained for overburden system

Pumping

Removal Pumping

COGO

Treatment Biological(In-Situ)

Physical/Chemical

g:proj^te: tron/techtype.xls

In-Situ Metals Employment of a series of wells for thePrecipitation injection of a molasses solution to

reduce hexavalent chromium to trivalentchromium and precipitation of trivalentchromium as a chromium hydroxide

Hydraulic Containment Employment of a series of conventionalgroundwater wells to recover/containgroundwater; wells are located such thatthe cones of depression formed achievethe desired recovery/containment

Retained

Recovery Wells

In-Situ MetalsPrecipitation


Employment of a series of conventionalgroundwater wells to recover/containgroundwater; wells are located such thatthe cones of depression formed achievethe desired recovery/containment

Precipitation of heavy metals via microbiallymediated in-situ geochemical changes

Employment of a series of wells toremediate/contain migration of contaminantsin groundwater; compressed air is injectedand strips organic compounds;VOC-containing air is captured by SVEby system; air sparge wells haveoverlapning zones of influence

Retained

Retained

Retained

Retained for overburden system

GERAGHTY & MILLE1WC.

age 2 of2

Table 2-2. Identification of Focused Feasible Technology Types and Process Options for On-site Groundwater,AVCO Lycoming Superfund Site, Williamsport, Pennsylvania.


Treatment(continued)

TechnologyType

Physical/Chemical(continued)

ProcessOption

In- Well Air Sparging

1Description

Employment of a series of wells toremediate/contain migration of contaminantsin groundwater; compressed air is injectedand strips organic compounds

1 ScreeningComments

Potentially applicable for bedrock

Chemical Precipitation

Air Stripping

Polishing Treatment Fume Incineration

Vapor-PhaseCarbon Adsorption

GOCDCD

CODisposal Surface Discharge Stream Discharge

Alteration of chemical equilibrium ofgroundwater to reduce contaminant(s)solubility, promoting precipitation ofcontaminant(s) out of groundwater

Passage of large volumes of air throughwater in a packed column to promotetransfer of VOCs to off gas, whichmay be treated by fume incineration orvapor phase carbon

Conversion of organic off-gases tocarbon dioxide and water with hightemperature combustion

Absorption of contaminants ontoactivated carbon by passing thecontaminated air stream throughcarbon columns or beds

Discharge of untreated or treatedgroundwater to Lycoming Creek viaOliver Street storm sewer

Retained; potentially applicable formetals and solids removal in treatinggroundwater

Retained

Retained

Retained

Retained for treated groundwater; notapplicable for untreated groundwater

g:project/textron/techtype.xlsGERAGHTY & MILLER, INC.

Table 2-3. Detailed Screening of Focused Technology and Process Options Retained for On-site Groundwater,AVCO Lycoming Superfund Site, Williamsport, Pennsylvania.

Page 1 of 3


TechnologyType

ProcessOptions Effectiveness Impiementability Cost

Containment In-Situ ReactiveZones or Curtains


- Minimal adverse impacts to humanhealth and the environment (HHE)

- May meet or approach groundwaterARARs

- Effective for long-term contaminantcontainment

- Pilot testing has demonstrated reliabilityand effectiveness

- Materials and equipment readilyavailable

-Treatment/disposal options wouldhave to be addressed for spent carbon

- Pilot testing has demonstratedimplementability

- Low to moderate Capital- Low to moderate O&M


• Minimal adverse impacts to HHE• May meet or approach groundwater

ARARs• Effective for long-term contaminant

containment• Pilot testing has demonstrated reliability

and effectiveness

- Materials and equipment readilyavailable

- No off-site TSD facilities needed- Pilot testing has demonstrated

implementability

- Low Capital- Low O&M

Pumping Hydraulic Containment

RemovalX*3DCOOCD

jjQTreatment

Pumping Recovery Wells

Biological(In-Situ)


- Effective for long-term groundwatercollection/containment

- May meet or approach groundwaterARARs in combination with othertechnologies

- Minimal adverse impacts to HHE

- Effective for long-term groundwatercollection/containment

- May meet or approach groundwaterARARs in combination with othertechnologies

- Minimal adverse impacts to HHE

- Will reduce chromium- Pilot testing has demonstrated reliability

and effectiveness- Low adverse impacts to HHE ,

- Materials and labor readilyavailable

• Treatment/disposal options wouldhave to be addressed for recoveredgroundwater

- Materials and labor readilyavailable

- Treatment/disposal options wouldhave to be addressed for recoveredgroundwater

- Pilot testing has demonstratedimplementability

- Equipment and labor are readilyavailable

High CapitalModerate to High O&M

High CapitalModerate to High O&M

Low CapitalLow O&M

g:project/textron/techop.xlsGERAGHTY & MILLEl^C


5e 2 of 3


TechnologyType

ProcessOptions Effectiveness Implementability Cost


Physical/Chemical Air Sparging/Soil Vapor Extraction

- Minimal adverse impacts to HHE- May meet or approach groundwater

ARARs- Effective for long-term contaminant

containment- Pilot testing has demonstrated reliability

and effectiveness

Materials and equipment readilyavailableTreatment/disposal options wouldto be addressed for spent carbonPilot testing has demonstratedimplementability.

• Low to moderate Capital• Low to moderate O&M

In-Well Air Sparging - Minimal adverse impacts to HHE- May meet or approach groundwater

ARARs- May be effective for long-term contaminant

containment

• Materials and equipment readilyavailable

• No off-site TSD facilities needed• Pilot testing would be required

• Moderate Capital• Moderate O&M

Chemical Precipitation • Effective and reliable conventionaltechnology for metals and solidsremoval

• Not suitable for organics removal• Could meet ARARs for metals• Minimal adverse impacts to HHE

expected

• Requires sludge treatment anddisposal

• Must meet ARARs for dischargeto creek

• Equipment and labor are readilyavailable

High CapitalHigh O&M

Air Stripping

CO" O""

CDrooCD

• Effective and reliable for removal of VOCs• Fouling problems possible• Does not remove metals, water soluble

organics, or non-volatile organics• Potential adverse impacts to HHE may

exist unless air emissions controls areimplemented

• Must meet ARARs for dischargeto creek or for reinjection

• May require further off-gas treatment• Materials and labor are readily

available

• High+F84 Capital(moderate capital withemissions controls)

• Low O&M (moderate tohigh O&M with emission

• controls)

Polishing Treatmentof Off-Gases

Fume Incineration • Provides 90 to 99+ percent removal oforganics

• Minimal adverse impacts to HHEexpected

• Would meet ARARs/TBCs for air

• Equipment and materials readilyavailable

• Requires compliance with air emissionstandards

• Moderate Capital• Moderate to High O&M

g:project/textron/techop.xlsGERAGHTY & MILLER, INC. O

of 3



TechnologyType

ProcessOptions Effectiveness Implementability Cost


Polishing Treatment Vapor-Phase - Not efficient at removing vinyl chlorideof Off-Gases Carbon Adsorption or dichloroethene(continued) - Potential adverse impacts to HHE

expected-Would meet ARARs/TBCs for air

Disposal Surface Discharge Direct Discharge ofTreated Water(Lycoming Creekvia Oliver Street stormsewer)

- Effective and reliable for treated groundwater

- Minimal adverse impacts to HHEexpected

- Equipment and materials readilyavailable

- Requires compliance with air emissionstandards

- Treatment/disposal options wouldhave to be addressed for spent carbon

- Requires treatment to meet NPDESpermit requirements

- Equipment and labor are readilyavailable

- Periodic inspection and maintenance

- Low Capital- Low to Moderate O&M

- Low to Moderate Capital- Low O&M

32*SOCOooPOCD

g:proiect/textron/techop.xlsGERAGHTY&MILLE1 1C.

I/)o

o<£O.

5£<oo>

sso

West Hilk .^;Estates*--"-:-.

12000 FEETPENNSYLVANIA,^———-^\

SCALE

SOURCE: U.S.G.S. W1UJAMSPORT PENNSYLVANIA1985 QUADRANGLES. PHOTOREVISED 1986. QUADRANGLE LOCATION

GERAGHTY& MILLER, INC.

Environmental ServicesA H«id«mij Company

SITE LOCATIONAVCO LYCOMING SUPERFUND SITE

W1LLJAMSPORT, PENNSYLVANIA

RGURE

1-1

AR.300202

I

in6

1

(U

i

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SCALF0 650 FEET

i VCLL

n*»we Kcovorv WELL• WUJMOratT NUMCPAL WATEt AUTHOHTY WCU.

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1

1


Environmental Services

TCE-DCE-VINYL CHLORIDEOVERBURDEN PLUME - OCTOBER 1995

TEXTRON LYCOMINGWILUAMSPORT. PENNSYLVANIA

FIGURE

A R 3 0 0 2 0 3

I

35

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Iu

I

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SCALE0 650 FEETH H H H H

« MONITORING vcu.Rccavoir vox

HUMCIPN. VATCT MmOWTY WOJ.

A SITE RECOVERY WILL

• STREAM GAUGE STATBN

3> TCC-OCC

£ GERAGHTY& MILLER, INC.


TCE-DCE IN BEDROCK WELLSOCTOBER 1995

TEXTRON LYCOMINGWILUAMSPORT, PENNSYLVANIA

FIGURE

1-3

f lR30020l*

•> SHALLOW WATCT TMLC HXVATON

SCALE:650 FEET 505

(FEET MOVE ME/W SCA LEVEL)

SHALLOW WATCH TMLC CONTOUR<MSMC1 W»OC trdMCK<nrr *»vc mm stA irvtu

1 GERAGHTY& MILLER, INC.


SHALLOW WATER TABLEOVERBURDEN AQUIFER - OCTOBER 1995

TEXTRON LYCOMINGWILUAMSPORT, PENNSYLVANIA

FIGURE

A R 3 0 0 2 0 5

IDWC PAIR 07-06-96 | PflXT NO.: NP02&3.003 j FIE: AVCO-LYCOH1NG | DRAIMNC: LYC-7 | CHECKED: J. MIHAUCH | APPROVED: J. MIHAUCH | DRAFTER: A. KINOSIAN

GOCDCDroCDen

GROUNDWATER FROMWESTERN PLANT AREARECOVERY WELLS

C66 GPM)_n

EQUALIZATIONTANK

(2,000 GALLONS)

GROUNOWATER FROMCENTRAL AND

EASTERN PLANT AREARECOVERY WELLS _n

EQUALIZATIONTANK

(5,000 GALLONS)

SOURCE) ERM 1991

<66 GPM)

CHEMICAL PRECIPITATION(IRON COPRECIPITATION)

SYSTEM

BLOWER(1,300 CFM)

(177 GPM)———————————— „_

(343 GPM£ BASKETFILTERS

BLOWER(1,300 CFM)

FUMEINCINERATOR

UNIT

AIR STRIPPER(4' DIAMETER AND20' PACKED DEEP)

OFF GASTO ATMOSPHERE

DISPOSAL TOLYCDMING CREEK


Environmental S«rvic«s

CONCEPTUAL FLOW DIAGRAMQROUNDWATER PUMP AND TREAT

AVCO LYCOMING SUPERFUND SITEWILLIAMSPORT. PENNSYLVANIA

FIGURE

2-1

|DWC DATE; 07-OC-ag | PfiXT NO.: NPO2&3.003 JFHE: LAMTEXTRON JDRAIMNC: TEX-S [CHECKED: J. taHAUCH [APPROVED: J. UtHAUCH [DRAFTER: A. KfttOStAN

AR

300207

1 __ rJ.1 "SSf* AIR FLOW J m-__L_1 1 —————————— GAUGE METER f

1 1 ML FREE _ , -. BALL[AIR COMPRESSOR — 1 <f VALVE (1 ————— E* ————— , AMBIENT AIR VALVE R, nurp

loo —— 1 ———— cxj ——————— |JPRESSURE

REGULATOR pRCJSOf(E

GAUGE '

li illlllP

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^^ff Environmental Services

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!

n i —— i VAPDR1 —— M ——— •$-] |=3 ————————— 1 FREATHENI

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~ —— ~—— ———— — _ _______ A ^7 \STAT1C WATER LEVEL

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tro oo

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SCHEMATIC DIAGRAM FIGURE

ING / SOIL VAPOR EXTRACTION 2-9AVCO LYCOMING SUPERFUNO SITE

^kWILLIAMSPORT. PENNSYLVANIA fc

COMPRESSED AIR TUBE

1

a-i

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5

i

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1

WATER TABLE

BENTOHITE SEALINTERNAL PIPE

EXTERNAL PIPE

UNTREATED WATER

PACKING MAY BE USED IN INTERNALCASING TO INCREASE SURFACEAREA FOR STRIPPING

LMQMiDWATERAIR/WATER MIXTUREAIR

GERAGHTYMILLER, INC.


SCHEMATIC DIAGRAMIN-WELL AIK SPARGING

AVCO LYCOMING SUPERFUND SITEWILUAMSPORT, PENNSYLVANIA

FIGURE

2-3

A R 3 0 0 2 0 8

IDWG DATE: 07-01-06 I PRJCT NO.: MP02S3.003 (HARD FILE: LYC-6 (DRAWING: LYC-6 [CHECKED: J. MIHALICH [APPROVED: J. UIHAUCH [DRAFTER: A. KINOSIAN

Cfs

LEGEND

• OVERBURDEN RECOVERY WELLS <33>CPRW-l THROUGH PRW-33)

\A BEDROCK WELLS

<BDW-t 1SW-3)

EXISTING GROUNDWATER FLOW DIRECTION

SCALE0 400 FEET

SDURCEt ERH 1991

GERAGHTYINC.

Environmental ServicesAH«ld«mlj Company

CONCEPTUAL LOCATION OFGROUNDWATER RECOVERY WELLS

AVCO LYCOMING SUPERFUND SITErfSBURG. PENNSYLVANIA

FIGURE

3-1

APPENDIX A

COST ESTIMATE DETAILS FOR ALTERNATIVES

A R 3 0 0 2 I OGERAGHTY & MILLER, INC.

of 2

COCDOro

Table A-1AAlternative G\V-3: Groundwater Collection, Chemical Treatment for Metals,

Air Stripping, Fume Incineration, and Discharge of Treated Water f

Estimated Capital Cost

ItemRecovery Wells - Central and Eastern Plant AreasRecovery Pumps - Central and Eastern Plant AreasRecovery Wells - Western Plant AreaRecovery Pumps - Western Plant AreaBedrock Recovery WellsBedrock Recovery PumpsSite PreparationWestern Influent Equalization TankEast and Cent. Influent Equalization TankProcess PumpsProcess PumpsMetals Removal/Recovery TreatabilityChemical Precipitation (Iron Co-Precipitation System)SamplerFlow MeterPiping through facility to Equalization TanksPiping from WWTP to Oliver StreetManholesHorizontal Boring of PipingHorizontal Boring Pits (8)Pipe BeddingTrench through plant facility to WWTPTrench from WWTP to Oliver StreetTrench Backfilling and CompactionFiltrationAir StripperFume Incineration

DescriptionInstall 22 well, 30 ft deep22 pumps and controls, 6 gpm ea., 0.5 HPInstall 1 1 wells, 30 ft deep1 1 pumps and controls, 6 gpm ea., 0.5 HPInstall 3 deep wells3 pumps and controls, 15 gpm ea., 1.0 HPMobilization/Demobilization2000-gallon cap., 1-FRP w/30 min. ret. time5000-gallon cap., 1-FRP w/30 min. ret. time2-70 gpm @ 50 ft head, 2.0 HP2-250 gpm @ 50 ft head, 7.5 HPTreatability study66 gpm system as manufactured by AndcoISCO or SigmaVenturi flow measuring device3450 If of 4-in dia. PVC pipe500 If of 12-in dia. gravity flow RCP2 precast concrete 4ft x 4ft x ft w/cover150 If of pipe bored under ex. util.8 f t x 8 f t x 4 f t /ea., totaling 75 cy10 in. deep incl. springline of pipe x 400 If, 19 cy4 ft deep, 2 ft wide, 3300 ft long4 ft deep, 3 ft wide, 400 ft long1050 cy incl. 5% shrinkage (- pipe vol. & bed.)3 basket filters1-4 ft dia. 20 ft packed depth, 3.0 HP blower1 -skid-mounted for 1300 cfm offgas

Unit Cost ($)$6,800$7,000

• $6,800$7,000

$42,500$7,500

Lump Sum$7,000

$17,400$7,000$7,300

$110,200Lump SumLump SumLump Sum

$17$15

$2,000$500$35$27

$5.25$5.25

$29$4,600

Lump SumLump sum

ea.ea.ea.ea.ea.ea.

ea.ea.ea.ea.est.

/If/Ifea./If/cy/cy/cy/cyicyea.

Installed Cost (S)$149,600$154,000$74,800$77,000

$127,500$22,500$23,200$7,000

$17,400$14,000$14,600

$110,200$366,300

$2,600$2,600

$58,700$7,500$4,000

$75,000$2,600

$500$5,100

$900$30,500$13,800

$102,000$263,600

FEASIB.XLS/table5E

GERAGHTY&'MILLE C. O

•ge 2 of 2

3DCOCDOroro

Table A-1AAlternative GW-3: Groundwater Collection, Chemical Treatment for Metals,

Air Stripping, Fume Incineration, and Discharge of Treated Water f


Item DescriptionPrefabricated Building Controls, lab, and other accessories, 560 sfSludge Pumps 1-pump and 1 spareSludge Piping 25 If of 4-in dia. PVC pipe

Total Direct Construction Cost (TDCC)

Engineering, Legal, Health & Safety, andConstruction Management @ 25% of TDCC

Subtotal

30% Contingency

Total Estimated Installed Cost w/30% Contingency (rounded to 2 figures)

Unit Cost ($) Installed Cost ($)$43.50 /sf $24,400$7,500 ea. $15,000

« $17 /If $400

$1,767,300

$441,800

$2,209,100

$662,700

$2,900,000

These costs are based on the costs in the 1991 Feasibility Study report, adjusted for 1996 based on a 3% per year inflation rate.

FEASlB.XLS/table5EGERAGHTY & MILLER, INC. o

X*soGOoCDroCO

Table A-1BAlternative GW-3: Ground Water Collection, Chemical Treatment for Metals,

Air Stripping, Fume Incineration, and Discharge of Treated Water. f

Estimated O&M Cost

Item QuantityFuelPowerIron Co-Precipitation OperationLaborChemicalsSolids DisposalOutside Analytical VerificationFive Year Performance Review

21,000 gal/yr274,300 kwh/yr34,689,600 gallons

6240 hoursLump Sum for metals removal40 tons/yr12 samplesAnnual cost equivalent of 5 year reviewat $23,200 each for 30 years3%ofTDCCEquipment Maintenance

Total

30% Contingency

Total Estimated Annual O&M Cost w/30% Contingency

Present Worth of O&M Cost (30 years @ 6%)

Total Present Worth - Capital Cost and O&M Cost (30 years @ 6%)

Unit Cost ($)$1.16 /gal$0.12 /kwh$0.46 /1000 gal *

$35.00 /hr$11,600

$375 /ton$1,400 /sample$8,800

Annual O&M Cost ($)$24,400$32,900$16,000

$218,400$12,800$15,000$16,800$8,800

$53,000

$398,100

$119,400

$51j7,50q

$7,100,000

$10,000,000

These costs are based on the costs in the 1991 Feasibility Study report, adjusted for 1996 based on a 3% per year inflation rate.

FEASIB.XLS/table6E

GERAGHTY&'MILLE

Item

Table A-2AAlternative Remedial Approach: Air Sparge, Soil Vapor Extraction,

and In Situ Metals Precipitation


Description Unit Cost ($) Installed Cost ($)

Pilot TestAk Sparge Wells, West Area and East AreaSoil Vapor Extraction WellsTrenching/Piping of the AS/SVE SystemAS/SVE Wellhead ConstructionAS/SVE System EquipmentMetals injection WellsTrenching/Piping of the Metals Injection SystemWellhead Construction of Metals Injection WellsMetals Injection System EquipmentMonitoring Well Installation

Air Sparging/Soil Vapor Extraction and Metals Injection Lump SumInstall 50 wells 25 ft deep and 49 wells 34 ft deep $1,100 ea.Install 20 wells 18 ft deep and 29 wells 30 ft deep $ 1,500 ea.Sawcutting, trenching, piping, backfilling, and blacktopping Lump SumConstruction of AS and SVE wellheads, 148 wells $400 ea.2 Carbon vessels, shed, compressor, blower, piping, electrical Lump SumInstall 18 wells 28' ft deep $ 1,500 ea.Install 1100 In ft trenching and 4400 hi ft of piping Lump SumInstall 18 wellheads $200 ea.Molasses Pump, 3 transfer pumps Lump SumInstall 10 monitoring wells - 2 for metals, 1 for AS/SVE $1,800 ea.

$150,000$108,900$73,500$170,100$59,200$258,600$27,000$66,000$3,600$44,400$18,000

3DCOOoro

Total Direct Construction Cost (TDCC)

Engineering, Legal, Health & Safety, andConstruction Management @ 25% of TDCC

Subtotal

30% Contingency

Total Estimated Installed Cost w/30% Contingency (rounded to 2 figures)

$979,300

$244,800

$1,224,100

$367,200

$1,600,000

FEASCOST.XLS/Capital Cost

GERAGHTY & MILLER, INC. O

Item

Table A-2BAlternative Remedial Approach: Air Sparge, Soil Vapor Extraction,

and In Situ Metals Precipitation

Estimated O&M Cost

Quantity Unit Cost ($) Annual O&M Cost ($)

CDCDroen

PowerMolasses TotesLaborCarbon ChangeoutsOutside Analytical Verification (Groundwater)Outside Analytical Verification (Air Samples)Hnu RentalDO/Redox Meter RentalFive Year Performance Review

Equipment Maintenance

Total

843,000 kwh/yr12 totes per year, each tote has 265 gal of Molasses2000 hours13,200 Ib of Carbon per year on average12 samples34 Samples per year17 Samplings per year17 Samplings per yearAnnual cost equivalent of 5 year reviewat $23,200 each for 30 years3%ofTDCC

$0.12 /kwh$400.00 /tote$35.00 /hr

Lump Sum$1,400 /sample

$400 /sample$180 /rental$55 /rental

$8,800

30% Contingency

Total Estimated Annual O&M Cost w/30% Contingency

Present Worth of O&M Cost (10 years @ 6%)

Total Present Worth - Capital Cost and O&M Cost (10 years @ 6%)

$101,200$4,800

$70,000$26,400$16,800$13,600$3,100

$900$8,800

$29,400

$275,000

$82,500

$2,600,000

FEASCOST.XLS/O&M Cost

GERAGHTY & MILLEW^C.

FOCUSED FEASIBILITY STUDY, OU 1 (COVER LETTER ATTACHED)

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