Revised Remedy Evaluation Reportdeq.wyoming.gov/media/attachments/Solid & Hazardous... · Remedy Evaluation Report Deluxe Cleaners and Tailors Cheyenne, WY September 12, 2014 Terracon

Revised Remedy Evaluation Report

Deluxe Cleaners and Tailors Project

Cheyenne, Laramie County, Wyoming

September 12, 2014

Terracon Project No. 24149060

Prepared for:

Wyoming Department of Environmental Quality Solid and Hazardous Waste Division, Voluntary Remediation Program

Cheyenne, Wyoming

Prepared by:

Terracon Consultants, Inc. Cheyenne, Colorado

TABLE OF CONTENTS

INTRODUCTION ......................................................................................................... 1 1.0

1.1 Site Description ............................................................................................... 1

1.2 Site Background .............................................................................................. 1

1.3 Report Objectives ............................................................................................ 1

1.4 Report Organization ........................................................................................ 1

1.5 Standard of Care ............................................................................................. 2

1.6 Additional Scope Limitations ........................................................................... 2

1.7 Reliance .......................................................................................................... 2

SITE CHARACTERIZATION RESULTS .................................................................... 3 2.0

2.1 Soil .................................................................................................................. 3

2.2 Groundwater .................................................................................................... 4

2.3 Soil Vapor and Indoor Air ................................................................................ 5

REMEDIAL ACTION OBJECTIVES ........................................................................... 6 3.0

3.1 Remediation Areas .......................................................................................... 6

3.2 Affected Media ................................................................................................ 6

3.3 Constituents of Concern .................................................................................. 6

3.4 Remedial Design Objectives ........................................................................... 6

FEASIBILITY STUDY ................................................................................................. 7 4.0

4.1 Site Logistical Issues for Remedy Evaluation .................................................. 7

4.2 Screening of Remedial Technologies .............................................................. 7

4.3 Development and Description of Remedial Technologies ............................... 9

4.4 Evaluation of Remedial Technologies ........................................................... 10

4.5 Comparison of Remedial Technologies......................................................... 14

4.6 Justification for Selection of Groundwater Remedial Alternative ................... 16

RECOMMENDED REMEDIAL ACTION ................................................................... 17 5.0

5.1 Description of the Recommended Soil Remedy ............................................ 17

5.2 Description of the Recommended Groundwater Remedy ............................. 17

5.3 Activities Necessary for Implementation........................................................ 17

5.4 Proposed Treatability Studies and Additional Site Characterization ............. 18

5.5 Proposed Criteria for Remedial Action Completion ....................................... 18

References ............................................................................................................... 19 6.0

TABLE OF CONTENTS (cont.)

APPENDICES APPENDIX A Figures

Figure 1 - Topographic Map Figure 2 – Site Diagram

Figure 3 – Soil Boring Diagram Figure 4 – Piezometric Flow Diagram, May 2, 2014 Figure 5 – Soil Analytical Diagram Figure 6 – Groundwater Analytical Diagram APPENDIX B Tables Table 1 – Remedial Technology Screening

Table 2 – Opinion of Probable Costs, Alternative S1 Table 3 – Opinion of Probable Costs, Alternative GW-1 Table 4 – Opinion of Probable Costs, Alternative GW-2

REVISED REMEDY EVALUATION REPORT DELUXE CLEANERS AND TAILORS PROJECT

CHEYENNE, LARAMIE COUNTY, WYOMING

Project No. 24149060 September 12, 2014

Resourceful ■ Responsive ■ Reliable 1

INTRODUCTION 1.01.1 Site Description The Deluxe Cleaners and Tailors (Site) is a site associated with the Wyoming Department of Environmental Quality, Solid and Hazardous Waste Division, Orphan Site Remediation Program (WDEQ-OSRP). The Site is located at 1614 House Avenue in Cheyenne, Wyoming and is an 8,712 square foot parcel bordered on the east by House Avenue, on the north by East 17th Street, on the west by a vacant parcel used as a parking lot and on the south by an alley that serves as a utility corridor and Carl’s Jr., a fast food restaurant. The eastern portion of the building is two stories and western portion is a single-story. A topographic map is shown on Figure 1 and a site layout is shown on Figure 2 included in Appendix A. The site is currently used by an active dry cleaner.

1.2 Site Background From prior to 1907 to after 1931, the site contained up to four small outbuildings associated with adjacent residential dwellings. Dry cleaning operations began prior to 1960 and continue through the present. The dry cleaner operates in a one and a half-story building built in 1945. A boiler room and solvent storage area are located in the rear (western) portion of the building. An underground storage tank (UST) was reportedly previously used at the site for solvent storage. A one-inch diameter, galvanized pipe was observed adjacent to the west wall of the building near the reported UST location.

1.3 Report Objectives The objectives of this Remedy Evaluation Report (RER) are to:

Identify potential treatment technologies and/or containment/disposal options for impacted unsaturated zone soil and groundwater

Evaluate alternatives against the evaluation criteria listed in VRP Fact Sheet 21 Perform a comparison of alternatives Select a remedy and provide a conceptual description

1.4 Report Organization The RER is organized as follows:

Section 1 includes the Site background. Section 2 summarizes previous investigations and the nature and extent of

impacted media. Section 3 outlines the remedial action objectives.

Remedy Evaluation Report Deluxe Cleaners and Tailors ■ Cheyenne, WY

September 12, 2014 ■ Terracon Project No. 24149060


Section 4 provides a description of remedial action alternatives, detailed analysis of the alternatives and a comparative analysis of the alternatives, and justification for selection of the proposed remedy.

Section 5 describes the proposed remedial action and a conceptual implementation.

Section 6 summarizes the remedial evaluation and selection action. Section 7 provides a list of references used in the report.

1.5 Standard of Care Terracon’s services were performed in a manner consistent with generally accepted practices of the profession undertaken in similar studies in the same geographical area during the same time period. Terracon makes no warranties, either express or implied, regarding the findings, conclusions or recommendations. Please note that Terracon does not warrant the work of laboratories, regulatory agencies or other third parties supplying information used in the preparation of the report. These services were performed in accordance with the scope of work agreed with you, our client, as reflected in our proposal.

1.6 Additional Scope Limitations Findings, conclusions and recommendations resulting from these services are based upon information derived from the on-site activities and other services performed under this scope of work; such information is subject to change over time. Certain indicators of the presence of hazardous substances, petroleum products, or other constituents may have been latent, inaccessible, unobservable, non-detectable or not present during site investigations, and we cannot represent that the site contains no hazardous substances, toxic materials, petroleum products, or other latent conditions beyond those previously identified. Subsurface conditions may vary from those encountered at specific borings or wells or during other surveys, tests, assessments, investigations or exploratory services; the data, interpretations, findings, and our recommendations are based solely upon data available at the time of this report preparation.

1.7 Reliance This report has been prepared for the exclusive use of WDEQ, and any authorization for use or reliance by any other party (except a governmental entity having jurisdiction over the site) is prohibited without the express written authorization of WDEQ and Terracon. Any unauthorized distribution or reuse is at the client’s sole risk. Notwithstanding the foregoing, reliance by authorized parties will be subject to the terms, conditions and limitations stated in the proposal, report, and Terracon’s Terms and Conditions. The limitation of liability defined in the terms and conditions is the aggregate limit of Terracon’s liability to the client and all relying parties unless otherwise agreed in writing.




SITE CHARACTERIZATION RESULTS 2.0An investigation was conducted in 2007 by Palmetto Environmental in conjunction with the adjacent Carl’s Jr. property. Tetrachloroethene (PCE) and its degradation products trichloroethene (TCE) and dichloroethene (DCE) were detected in samples collected from seven groundwater monitoring wells. PCE concentrations ranged from 42.4 micrograms per

liter (g/L) in the most downgradient well, MW-03, to 567 g/L in MW-07, located nearest to the dry cleaner. EnviroGroup Limited conducted a subsequent investigation in 2010 that included installation of six soil vapor points. Elevated concentrations of PCE and TCE were detected in soil vapor samples with constituent concentrations in ESV-01 through ESV-04 reported above their respective WDEQ soil vapor screening levels. The highest concentrations of soil vapor and groundwater were detected near the reported UST location. The depth of contamination was reported to the extent of the depths investigated to date. Terracon conducted additional site assessment activities in May 2014, which were summarized in a site characterization report (SCR) (Terracon 2014). The SCR was able to:

Delineate the approximate extent of site impacts in soil and groundwater Verify a UST could not be located using GPR and EM locating techniques Determine that vapor intrusion was not a concern at the off-site Carl’s Jr. restaurant

A summary of impacted media is presented below.

2.1 Soil Based on May 2014 soil results, soil impacts are concentrated in the vicinity of the northwestern portion of the Deluxe Cleaner building. Impacts in this area are estimated to comprise an area measuring at least 45 feet by 45 feet and extend vertically 15 feet to the water table. Based on existing data, at least 1,125 cubic yards of soil is impacted with PCE at concentrations above the migration to groundwater clean-up standard. The majority of these impacts are located beneath the Deluxe Cleaner building. Other potential areas with residual PCE mass in the vadose zone were not identified. The highest concentrations in soil samples were observed in the interior borings SB-2 (adjacent to the dry cleaner machine) and SB-1 (near solvent storage). The interior impacts may be related to releases originating from sub-slab piping that lead to a UST or surface spills originating from material transfer and storage in the dry cleaning machines. PID readings at SB-4 and SB-6 increased several orders of magnitude with depth, which is indicative of a sub-surface release (possibly from a UST or associated piping).




PCE was reported at concentrations ranging from 2.1 micrograms per kilogram (g/kg) to

15,000 g/kg. PCE concentrations were below the WDEQ residential clean-up standard

(22,000 g/kg), but exceeded the WDEQ migration to groundwater standard (2.1 g/kg).

2.2 Groundwater Groundwater results from temporary wells indicated that the plume extends south-southwest from the Deluxe Cleaners building beneath the Carl’s Jr. and is mostly contained on one city block bordered by Warren Avenue, 17th Street, House Avenue, and Lincoln Way. Detections of chlorinated solvents in TW-15 and TW-16 at the northwest corner of Lincoln Way and Warren Avenue on Property No. 7 show that contamination extends across Lincoln Way to the south.

The highest concentrations of chlorinated ethenes were observed in MW-7 (4,233.6 g/L), located immediately downgradient of the Deluxe Cleaner building. The existing network of 15 shallow wells generally defines the extent of impacts greater than WDEQ standards with the exception of the southern-most edge of the plume beyond MW-11. A summary of detected compounds is presented below:

PCE was detected in 12 wells at concentrations from 2.5 to 390 g/L

TCE was detected in 8 wells at concentrations from 34 to 1,200g/L

Cis-1,2-DCE was detected in 9 wells at concentrations from 3.1 to 2,100 g/L

1,1-DCE was detected in MW-7 at a concentration of 3.6 g/L

Vinyl chloride was detected in 4 wells at concentrations of 2.6 to 540 g/L

Benzene was detected at a concentration of 5.1 g/L in MW-3 Existing wells MW-1 through MW-7 were previously sampled by others in 2007. PCE concentrations observed in these wells during the 2014 sampling event were generally consistent with concentrations reported seven years ago, providing evidence that the plume likely in steady state. The lack of decline in PCE concentrations may be indicative of residual source material leaching into groundwater. Select field parameters measured during the May 2014 sampling event are summarized below:

dissolved oxygen ranged from 0.21 to 4.98 milligrams per liter (mg/L) pH values ranged from 6.80 to 7.63 standard units oxidation reduction potential was between -158.80 and 281.70 millivolts (mV)

Aquifer conditions were generally anaerobic and reducing with dissolved oxygen concentrations below 1.0 mg/L in seven monitor wells.




2.3 Soil Vapor and Indoor Air PCE was detected in four exterior soil vapor points (ESV-1 through ESV-4) at concentrations above the WDEQ residential soil vapor screening level. TCE was detected above the residential screening levels in three samples (ESV-1, ESV-2, and ESV-4). The highest concentrations were observed in ESV-1 and ESV-2, which are located near the northwest corner of the Deluxe Cleaner building. The area of highest soil vapor concentration coincides with areas of highest soil and groundwater impacts (i.e., northwest corner of the Deluxe Cleaner building). The lateral extent of soil vapor impacts generally mirrors that shallow groundwater impacts. A summary of detected compounds is presented below:

PCE was detected in 4 soil vapor samples at concentrations from 22,000 to 880,000

g/m3 TCE was detected in 4 soil vapor samples at concentrations from 47 to 320,000

g/m3 Cis-1,2-DCE was detected in 4 soil vapor samples at concentrations from 21 to

40,000 g/m3 High concentrations of chlorinated ethenes were also observed in vapor samples collected from two sub-slab points at Deluxe Cleaners and two sub-slab points at Carl’s Jr. The samples from SSVP-3 and SSVP-4, which are located in the Deluxe Cleaner building, had

elevated concentrations of PCE at 6,400,000 g/m3 and 41,000 g/m3, respectively,

compared to a WDEQ screening level of 810 g/m3. PCE concentrations in sub-slab vapor concentrations collected at the Carl’s Jr. building also exceeded its screening level, with concentrations up to 8,800 µg/L.

PCE was detected in an indoor sample (2.8 g/m3) collected at Carl’s Jr. and an

outdoor/background sample (4.5 g/m3). Though PCE was detected in sub-slab vapor samples, the indoor air detection was not attributed to vapor intrusion based on the outdoor sample results. The data indicates that the vapor intrusion pathway is incomplete at the Carl’s Jr. As such, vapor remedies are not evaluated in this report.




REMEDIAL ACTION OBJECTIVES 3.0This section summarizes the areas of the Site to be remediated, the affected media, key constituents of concern (COCs), the remediation design goals and applicable cleanup standards.

3.1 Remediation Areas Active remediation is recommended in the general location of the northwest corner of the Deluxe Cleaners building. The approximate area of recommended remediation is shown on Figure 5 and Figure 6.

3.2 Affected Media Soil and groundwater impacts are present at the Site. Soil impacts are limited to the vicinity of the Deluxe Cleaners building with the highest concentrations located beneath the northwest corner of the building. Groundwater is impacted in the unconsolidated surficial aquifer at depths of approximately 15 ft bgs to more than 25 ft bgs. Groundwater impacts extend a distance of over 400 feet downgradient from the Deluxe Cleaners building. Though soil gas is impacted, indoor air sampling indicate that the vapor intrusion pathway is likely incomplete at the Carl’s Jr. restaurant.

3.3 Constituents of Concern The applicable COCs to be targeted for remediation include volatile organic compounds (VOCs) associated with dry cleaning operations including PCE and its degradation products: TCE, 1,2-cis-DCE, 1,2-trans-DCE, 1,1-DCE, and vinyl chloride.

3.4 Remedial Design Objectives The remedial design goals include:

Reduce vadose zone soil mass within the northwest corner of the Deluxe Cleaners and diminish its potential to act as a continuing source to groundwater impacts

Reduce the dissolved phase of the shallow groundwater contamination down-gradient of the Deluxe Cleaners to shrink the dissolved plume and reduce the impacts to off-site properties

Reduce source area and down-gradient soil and groundwater impacts that are contributing to degradation of soil vapor to diminish the potential for soil vapor to migrate into nearby structures and utilities




FEASIBILITY STUDY 4.0This section outlines the screening of remedial technologies, formulation, evaluation and comparison of remedial alternatives that meet the following minimum standards for remedy selection:

Be protective of human health, safety and the environment Remediate contaminated air, soil and water affected by the site to applicable cleanup

levels Control any sources of releases to reduce or eliminate, to the extent technically

practicable, further releases as required to protect human health and the environment

Comply with applicable standard for management of wastes generated as a consequence of the remedy

4.1 Site Logistical Issues for Remedy Evaluation The Deluxe Cleaners is an active dry cleaner on a small parcel with limited space for remedial operations. The building is located along the western and southern property boundary, which limits access. An active drive through is oriented east-west along the northern side of the building. The southern side of the building is bordered by an alley that includes subsurface and overhead utilities. The dry cleaner is anticipated to be active during remedial operations. Based on the current configuration of the building interior, there is not sufficient space to allow for implementation of remedial efforts inside the building. The downgradient portion of the dissolved phase groundwater plume is located beneath several parking lots and an active fast food restaurant, Carl’s Jr., with a drive-through. The parking lots are utilized seven days a week and are busiest Monday through Friday during normal business hours. The Carl’s Jr. is open seven days a week from early morning through late evening. Remedial efforts will need to accommodate business operations at the Deluxe Cleaners, the Carl’s Jr. restaurant, and allow for parking access.

4.2 Screening of Remedial Technologies Potentially applicable treatment, recovery, and containment technologies were identified for implementation at the Site. The technologies and process options were screened based on effectiveness, implementability, and relative cost. Based on the technology screening, select technologies were retained and combined to form remedial alternatives as described in the subsequent sections. Table 1 in Appendix A includes a summary of the remedial technology screening.




The following soil remedy was considered the most appropriate and was selected for further feasibility and cost analysis:

In-situ treatment via soil vapor extraction (SVE). The following potential soil remedies were eliminated from further consideration: Soil Remedy Rationale

Institutional Controls including deed notice/restrictions, and other engineering controls such as fencing;

Did not offer long-term protectiveness of groundwater and concerns related to potential vapor intrusion if properties are re-developed

Removal/Disposal options including excavation and offsite disposal;

Site access restrictions as described in Section 4.1 prohibited access to vadose zone mass beneath the building

In-situ Treatment such as chemical oxidation, bioremediation, and chemical reduction.

Site access restrictions as described in Section 4.1 prohibited access to vadose zone mass beneath the building

The following groundwater remedies were considered the most appropriate and were selected for further feasibility and cost analysis:

Enhanced reductive dechlorination (anaerobic bioremediation) Monitored natural attenuation

These groundwater remedies were deemed appropriate for evaluation based on favorable aquifer geochemical conditions and high ratio of degradation products in relation to PCE. Additionally, the lack of downgradient receptors, anticipated stable plume conditions, and absence of a completed vapor intrusion pathway suggest that MNA may be an appropriate remedy. The following potential groundwater remedies were eliminated from further consideration:

Groundwater Remedy Rationale In-situ chemical oxidation (ISCO) Aquifer is already in optimum condition for a

reductive technology (e.g. currently anaerobic and reducing) with significant daughter product formation

In-situ chemical reduction (ISCR) Though aquifer conditions are conducive for ISCR, similar reductions can be achieved via ERD using less expensive amendments

Thermal treatment Treatment volume and depths are not cost effective to warrant thermal treatment

Permeable reactive barrier

Length of time required for remediation and site access limitations as described in Section 4.1




The remediation technologies selected for the site are discussed further in the following section.

4.3 Development and Description of Remedial Technologies Based on the general response actions, remedial technologies, and screening of technologies in Section 4.2, the following alternatives were developed:

Alternative S1: SVE Alternative GW1: ERD and MNA Alternative GW2: MNA

A conceptual description of each remedial alternative is provided below.

Alternative S1 – Soil Vapor Extraction 4.3.1Alternative S1 consists of a soil vapor extraction system to reduce soil contamination in the vadose zone. The SVE technology involves application of vacuum in the subsurface and extraction of vapor-phase VOCs from the unsaturated zone impacted soils. The vapor phase contaminants are extracted using SVE wells screened above the water table (vadose zone). The primary purpose of SVE is physical removal of contaminants in the vadose zone. The increased air movement through the unsaturated zone can potentially offer the benefit of enhanced aerobic biodegradation by increasing oxygen levels within unsaturated zones. The general soil lithology at the site includes unconsolidated silty sand, sand with gravel and sandy clay, which is generally conductive to SVE technology.

Alternative GW-1 – Enhanced Reductive Dechlorination and MNA 4.3.2Alternative GW-1 consists of an active remediation approach to treat source area groundwater impacts through the addition of a soluble carbohydrate to stimulate enhanced reductive dechlorination (ERD) and an MNA for remediation of the down-gradient plume. The injection of high fructose corn syrup (HFCS) solution into source area permanent injection wells has the potential to degrade site COCs in situ by enhanced anaerobic processes. These types of contaminants include chlorinated solvents. With anaerobic biodegradation, the target contaminant PCE is broken down to intermediate byproducts (including TCE, DCE, vinyl chloride, ethene, and ethane) and then further broken down to the final byproducts of carbon dioxide and water. Based on available site groundwater analytical data, anaerobic bacteria may already be degrading site COCs. PCE by-products TCE, cis-1,2-DCE and vinyl chloride have been detected in site wells. These data suggest ERD is an applicable technology for site remediation. Alternative GW-1 is compatible for implementation with Alternative S1 as the treatment areas and depths do not coincide. Additionally, potential changes in vadose zone oxygen levels as a result of the SVE system are not anticipated to change conditions in the saturated zone.




Alternative GW-2 – MNA 4.3.3Alternative GW-2 provides for an MNA approach for the remediation of groundwater impacts to be completed with Alternative S1 to reduce the residual contaminant mass of soil contamination leaching into the groundwater. This option assumes the on-going natural attenuation processes at the site will continue to decrease constituent concentrations at the source and deplete contaminant mass. MNA relies on a series of biological and physical processes to eliminate mass and decrease concentrations through biodegradation, dispersion, dilution, sorption, and hydrolysis. It is important to note that success implementation of MNA also requires completion of Alternative S1 (i.e., reduction of residual mass leaching into groundwater).

4.4 Evaluation of Remedial Technologies In this section, the remedial alternatives for soil described in the previous section are evaluated using the criteria listed in VRP fact sheet No. 21 (Remedy Selection) and fact sheet No. 26 (Monitored Natural Attenuation).

Detailed Analysis of Alternative S1 – Soil Vapor Extraction 4.4.1Long Term Effectiveness Magnitude of Residual Risk: Since the soil above applicable clean-up goals will be treated in Alternative S1 via SVE, there will be no future anticipated residual exposure risks at the Site to industrial workers after the applicable goals are achieved. Natural processes are expected to further reduce concentrations of constituents in the remaining soil that may contain contaminants below the applicable clean-up goals. Reduction in Toxicity, Mobility, or Volume Alternative S1 would reduce the volume of contaminated soil at the Site. Soil gas would be extracted and treated aboveground with the treatment system. Since the contaminated soil would be treated by the extraction and treatment of volatilized contaminants, and aerobic biodegradation could be potentially enhanced, this alternative is also expected to reduce toxicity and mobility of constituents. Short Term Effectiveness This alternative would require protection against potential risks as a result of exposure to contaminated soil during implementation. For example, extraction of soil vapor and treatment aboveground may result in fugitive emissions, but using appropriate engineering controls would reduce these emissions (e.g., volatiles). This action is expected to present minimal short-term impact to the community. Engineering controls, personal protective equipment, and environmental monitoring equipment would be used to minimize risk for exposure to workers during construction activities.




Adverse Impacts from Implementation Alternative S1 is expected to be protective of human health and environment. With SVE, exposure route(s) for soil constituents at the Site will be eliminated and Site cleanup to applicable standards will be achieved. Due to treatment of impacted soil, impact to groundwater and soil vapor is likely to be minimized. This alternative is expected to cause minimal disruption to the local community. Implementation would require coordination with the Deluxe Cleaner property during installation of SVE wells and associated piping. A suitable location for the system would need to be identified as well. Operation of the system will generate noise that may be heard on adjacent properties. Ability to Achieve Cleanup Levels SVE is an efficient remedial technology that can achieve the clean-up goals given adequate system design and well spacing. SVE has a successful track record and is still the most commonly implemented in situ soil remedy (EPA 2013). It has the potential to remediate soils beneath the building as well as beneath the adjacent parking areas. Future Land Use Given the technological ability of SVE to achieve clean-up goals, restrictions on future land use of the site are not anticipated. Implementability and Complexity of Remedy The construction of an SVE system can be implemented using conventional construction equipment. Alternative S1 would utilize standard construction methods and equipment. The availability of technologies, special equipment, or specialists is not a consideration or limiting factor for this alternative. Installation of horizontal SVE wells in lieu of interior vertical wells is anticipated to minimize distributions to Deluxe Cleaners. Cost The present worth of an opinion of probable cost for Alternative S1 is approximately $548,000. Present worth was calculated using a discount rate of 5 percent. A conceptual design used to develop the costs is presented in Section 5.1 and details of the probable cost and key assumptions are included in Table 2. It should be noted that these costs are for evaluation of alternatives and actual costs of implementation may vary (typically around -30 to +50 percent).

Detailed Analysis of Alternative GW-1 – Enhanced Reductive 4.4.2Dechlorination

Long Term Effectiveness ERD is anticipated to be effective at achieving clean-up levels within the treatment area in a timeframe spanning several years. Its effectiveness is dependent upon amendment




distribution and maintaining adequate carbon levels and favorable biogeochemical conditions within the aquifer. The detections of vinyl chloride in existing wells are evidence that complete dechlorination can be anticipated without the need for bioaugmentation. Natural processes are expected to further reduce concentrations of constituents in the groundwater that may contain contaminants below the applicable clean-up levels. Reduction in Toxicity, Mobility, or Volume ERD would result in the elimination of dissolved phase mass within the treatment area. Additionally, it has the potential to desorb residual sorbed mass within the saturated zone. Once in the dissolved phase, this residual mass also has the potential to be degraded. Contaminant toxicity will not be ultimately reduced until complete dechlorination (i.e. ethene formation) is achieved. Short Term Effectiveness Degradation of parent compounds is typically observed within the first several months of implementation. Several intermediate degradation products are typically formed via the hydrogenolysis degradation pathway before achieving complete dechlorination. The degradation intermediaries represent approximately the same risk as the parent compounds. Adverse Impacts from Implementation This action is expected to present minimal short-term impact to the community. Engineering controls, personal protective equipment, and environmental monitoring equipment would be used to minimize risk for exposure to workers during construction activities. The generation of degradation products does not pose any greater risk than that the original parent compounds. Due to treatment of source groundwater, downgradient groundwater and soil vapor impacts are anticipated to improve. This alternative is expected to cause some disruption to Deluxe Cleaners operations during the injection and monitoring events. Implementation will also require the installation of several additional injection and monitoring wells. Ability to Achieve Cleanup Levels ERD is a well-established remedy with a good track record of success. In past implementations, it was able to reduce parent concentrations by over 95 percent and achieve total chlorinated VOC reduction of 62 percent (McGuire 2006). It is anticipated to be able to achieve the clean-up levels. Future Land Use Given that ERD is anticipated to achieve clean-up goals, restrictions on future land use of the site are not anticipated. Additionally, the depth to groundwater (approximately 15 ft bgs) and lack of receptors minimize the potential risk to future occupants and/or workers.




Implementability and Complexity of Remedy ERD can be easily implemented using conventional construction equipment. Installation of the wells and subsequent injections will utilize standard construction methods and equipment. The availability of technologies, special equipment, or specialists is not a consideration for this alternative. Cost The present worth of an opinion of probable cost for Alternative GW-1 is approximately $683,000. Present worth was calculated using a discount rate of 5 percent. A conceptual design used to develop the costs is presented in Section 5.2 and details of the probable cost and key assumptions are included in Table 3. It should be noted that these costs are for evaluation of alternatives and actual costs of implementation may vary (typically around -30 to +50 percent).

Detailed Analysis of Alternative GW-2 – Monitored Natural Attenuation 4.4.3Long Term Effectiveness ERD is anticipated to be effective at achieving clean-up levels within the treatment area in a timeframe spanning several decades. Many of the physical processes (e.g., dispersion, dilution, and sorption) are anticipated to continue occurring without interruption. Evidence of biodegradation is apparent through the detection of degradation products. Future biodegradation will be depended upon favorable biogeochemical conditions within the aquifer. Reduction in Toxicity, Mobility, or Volume Physical MNA processes would be responsible for reductions in constituent concentrations as well as potentially limiting mobility through sorption. Given the age of the facility and anticipated length of time since past releases, the plume is likely in steady state and additional migration or increases in volume are anticipated to be minimal. Reduction in contaminant toxicity is dependent upon biodegradation processes, which have been naturally occurring at the site (as evidence by detections of TCE, DCE isomers, and vinyl chloride) under favorable geochemical conditions. The presence of ferrous iron (e.g. MW-10 and MW-13) has the potential aid in degradation via abiotic pathways. Short Term Effectiveness Biodegradation has already been observed at the site in recent monitoring events. Elimination of the vadose zone source material will allow the remainder of the plume to naturally attenuate. Continued chlorinated ethene degradation is anticipated. Adverse Impacts from Implementation This action is expected to present minimal short-term impact to the community. Implementation would consist of periodic groundwater monitoring events. The existing well




network is anticipated to be sufficient from the MNA program. Disruptions to property occupants, if any, from the sampling events are expected to minimal. The generation of degradation products should not pose any greater risk than that the original parent compounds. Ability to Achieve Cleanup Levels After treatment of vadose source material, MNA has the potential to reach the clean-up levels, albeit it over a long time period. Existing data indicates that aquifer conditions are favorable for continued dechlorination. Constituent concentrations will be further reduced towards clean-up levels through sorption, dilution, and dispersion. Additionally, there is the potential for abiotic degradation aided by the presence of dissolved iron. Future Land Use Given that MNA is anticipated to achieve clean-up goals, restrictions on future land use of the site are not anticipated. Additionally, the depth to groundwater (approximately 15 ft bgs) and lack of receptors minimize the potential risk to future occupants and/or workers. Implementability and Complexity of Remedy MNA implementation is anticipated to utilize the existing well network. It does not rely on unique technologies, special equipment, or specialists. The sampling protocol uses standard procedures and samples will be analyzed using established laboratory analyses. Cost The present worth of an opinion of probable cost for Alternative GW-1 is approximately $294,000. Present worth was calculated using a discount rate of 5 percent. Details of the probable cost and key assumptions are included in Table 4. Costs are based on sampling the existing network of 15 monitoring wells quarterly for 2 years, semi-annually for 2 years, and annually for 6 years for VOCs. A select sub-set of 6 wells that represent upgradient, source area, and downgradient conditions will be monitored for MNA parameters on a semi-annual basis for four years (8 events). For cost estimating purposes, it is anticipated that VOC monitoring will continue for 30 years. Details of the probable cost and key assumptions are included in Table 2. It should be noted that these costs are for evaluation of alternatives and actual costs of implementation may vary (typically around -30 to +50 percent).

4.5 Comparison of Remedial Technologies The following section presents a comparison of the alternatives presented above. Given that only one soil alternative was deemed practical for implementation given the existing site limitations; a comparison of soil technologies is not included.




Long Term Effectiveness 4.5.1Alternative GW-1 and Alternative GW-2 will both provide a permanent remedy after soil treatment, if implemented effectively and given sufficient time. They will require performance monitoring to assess their effectiveness. Alternative GW-1 and Alternative GW-2 are both anticipated to effectively mitigate future exposure risks to site workers given its anticipated use as a dry cleaner. Given the potential for enhanced biodegradation, Alternative GW-1 will likely have a shorter remediation timeframe.

Reduction in Toxicity, Mobility, or Volume 4.5.2Alternative GW-2 is anticipated to decrease constituent concentrations and provide modest reductions in contaminant mobility. The addition of a carbon amendment in Alternative GW-1 will allow for greater biodegradation than Alternative GW-2. Thus Alternative GW-1 will likely result in more reductions in toxicity and volume than GW-2.

Short Term Effectiveness 4.5.3The detection of intermediate degradation products provides evidence that biodegradation is already occurring at the site. Thus, Alternatives GW-1 and GW-2 will be effective to some degree in the short-term. Degradation from the addition of soluble carbohydrate in Alternative GW-1 will allow for dechlorination to progress at a faster rate than Alternative GW-2.

Adverse Impacts from Implementation 4.5.4While both alternatives are anticipated to have minimal adverse impacts from implementation, Alternative GW-2 does not require additional well installation or active remediation activities. Thus, it will have the least impact on the site and adjacent properties. Both alternatives will generate compounds that are similar in toxicity to the parent compounds. Additionally, there is a lack of groundwater receptors. As such, the alternatives are expected to reduce groundwater contamination without adverse impacts.

Ability to Achieve Cleanup Levels 4.5.5Alternatives GW-1 and GW-2 are anticipated to be technologically capable of obtaining clean-up levels. Alternative GW-2 will require long-term monitoring to assess performance before applicable clean-up levels are achieved.

Future Land Use 4.5.6Alternatives GW-1 and GW-2 are not anticipated to impact or restrict future land use. Both options are anticipated to eventually achieve clean-up levels, thus permanent land use or engineering controls will not be needed. Alternative GW-1 is anticipated to reach clean-up levels first and return the property to unrestricted use sooner than Alternative GW-2. If future land use or re-development was initiated prior to completion of performance monitoring, care would need to be taken to not disturb the well network.




Implementability and Complexity of Remedy 4.5.7Implementation and performance of monitoring of Alternative GW-1 can be easily achieved using conventional drilling techniques and injection procedures. Given that Alternative GW-2, will not require additional wells or active remediation, it is deemed to less complex and simpler to implement than GW-1.

Cost 4.5.8The present worth opinion of probable costs for Alternatives GW-1 and GW-2 are $683,000 and $294,000, respectively. Alternative GW-1 offers the benefit of a shorter remediation timeframe, but this also results in payment over a shorter period of time. Additionally, a large percentage of the costs associated with Alternative GW-1 occur during the first two years of implementation of the injections.

4.6 Justification for Selection of Groundwater Remedial Alternative Based on the comparison of soil alternatives in Section 4.6, both alternatives are expected to be protective of human health and environment and meet the clean-up levels. Overall Alternative GW-1 is the most feasible effective groundwater remedy for the Site that is likely to achieve the clean-up goals in a reasonable timeframe. It provides protection of human health and environment. It also has the potential to address residual sorbed material in the source area if it exists. For these reasons, Alternative GW-1 is overall the most effective alternative to address groundwater impacts at the Site and is recommended as the groundwater remedy.




RECOMMENDED REMEDIAL ACTION 5.0

5.1 Description of the Recommended Soil Remedy The recommended soil remedy for the Site is SVE. It involves treatment of approximately 1,400 cy of impacted material from 0 to 15 ft bgs. The proposed treatment area is depicted in Figure 5. The general soil lithology at the site includes unconsolidated silty sand, sand with gravel and sandy clay, which is generally conductive to SVE technology. Specific system design criteria should be determined after completion of a pilot test at the site. It is assumed the system will be comprised of a combination of 4 vertical wells and three horizontal wells. Vertical SVE wells would be installed to depths of approximately 13 ft bgs and screened in the unsaturated zone in the interval of 3 to 13 ft bgs. Horizontal wells would be installed at a depth of 5 feet bgs with lateral screens of 30 feet. The volatilized vapors will be extracted via the SVE wells, and treated using vapor-phase treatment units (if needed), and subsequently discharged into the atmosphere. The SVE wells will be connected via subsurface polyvinyl chloride (PVC) piping which will be connected to the SVE system. A monitoring program will be implemented to gauge system performance and is anticipated to include semi-annual sampling and analysis of soil and vapor samples. In addition, air samples after vapor phase treatment will be collected for analysis of vapor phase VOCs to monitor air emissions. For the purposes of evaluation, the SVE system is assumed to be operated for a period of 3 to 5 years. A vapor phase granular activated carbon treatment vessels may be required for treatment of recovered vapors prior to their discharge into the atmosphere.

5.2 Description of the Recommended Groundwater Remedy The selected groundwater remedy for the site is ERD and MNA. The ERD treatment will be focused on the source area groundwater. It involves the active remediation of approximately 10,000 square feet of the surficial aquifer from depths of 15 ft bgs to 25 ft bgs. It is assumed that implementation will utilize approximately 16 permanent injection wells during three injection events over a 1.5 year period. The active treatment area will be monitored quarterly for four years followed by one year of semi-annual monitoring and annual monitoring for 5 additional years, as needed. Wells outside of the treatment area (i.e., downgradient MNA area), will be monitored quarterly for 2 years followed by semi-annually for 2 years, and annually for 6 years, as needed.

5.3 Activities Necessary for Implementation Following activities are associated with implementation of the proposed remedy:




SVE pilot testing Work plans for SVE and ERD implementation Site and utility clearance and determination of work areas Installation of the well network Procurement of HFCS for injection Obtain applicable permits Baseline sampling events Remedy implementation Performance monitoring

5.4 Proposed Treatability Studies and Additional Site Characterization Prior to finalization of the SVE design, a small pilot test is recommended to confirm the anticipated radius of influence and assist in sizing the blower. Groundwater remediation design can be improved with the collection of additional site data including hydraulic conductivity and porosity. Slug tests should be performed on select monitoring wells located in the source area. A soil core should be collected to estimate the porosity of soil within the shallow aquifer.

5.5 Proposed Criteria for Remedial Action Completion The remedial action, which will include implementing the selected soil and groundwater remedies for the Site, will be continued until compliance with clean-up levels are achieved or remedies reach a state of diminishing returns that no longer warrant their associated costs. Soil cleanup levels shall comply with both residential health-based and protection of groundwater levels. Soil remedial goals conform to those specified in VRP Fact Sheet No. 12 Soil Clean-up Levels and the most recent version of the Cleanup Level Look-up Table. Groundwater cleanup levels shall be consistent with those specified in VRP Fact Sheet No. 13 and the most recent version of the Cleanup Level Look-up Table. The applicable groundwater levels are a combination of the EPA maximum contaminant levels (MCLs) and Water Quality Chapter 8 standards. For compounds that do not have promulgated concentrations, cleanup levels can be calculated in accordance with the equations in the Water Quality Rules and Regulations, Chapter 17, Part J.




REFERENCES 6.0 EPA, 2013. Superfund Remedy Report, Fourteenth Edition. Solid Waste and Emergency Response. EPA 542-R-13-016. McDade, J.M., McGuire, T.M., and Newell, C.J., 2005. Analysis of DNAPL Source Depletion Costs at 36 Field Sites, Remediation, 2005, 15(2). McGuire, T.M., Newell, C.J., Looney, B.B., Vangelas, K.M., and Sink, C.H., 2004. Historical Analysis of Monitored Natural Attenuation: A Survey of 191 Chlorinated Solvent Sites and 45 Solvent Plumes, Remediation, 15(1), 99-112. McGuire, T.M., McDade, J.M., and Newell, C.J., 2006. Performance of DNAPL Source Depletion Technologies at 59 Chlorinated Solvent-Impact Sites, Groundwater Monitoring and Remediation, Vol. 26, No. 1, pg 73-84.

APPENDIX A

Figures

APPENDIX B

Tables

PRO

JEC

T N

AM

E: D

elux

e D

ry C

lean

ers

Orp

han

Site

PRO

JEC

T LO

CA

TIO

N:

Che

yenn

e, W

yom

ing

PRO

JEC

T N

UM

BER

: 24

1490

60

TAB

LE 1

REM

EDIA

TIO

N T

ECH

NO

LOG

Y SC

REE

NIN

G

Groun

dwater

Soil

Rem

edie

s

Institutio

nal Contro

ls inclu

ding

deed notic

e/res

tricti

ons, an

d other

enginee

ring co

ntrols

such

as

fencin

gRem

oval/D

isposa

l optio

ns inclu

ding

exca

vatio

n and offs

ite disp

osal

In-situ Trea

tmen

t such

as ch

emica

l

oxidati

on, biorem

ediat

ion, and

chem

ical re

duction

In-situ tr

eatm

ent v

ia so

il vap

or

extra

ction (S

VE)

In-situ ch

emica

l oxid

ation (IS

CO)

In-situ ch

emica

l reducti

on (ISCR)

Thermal

treatm

ent

Permea

ble rea

ctive

barrier

Enhance

d reducti

ve dec

hlorinati

on

(anae

robic

bioremed

iation)

Monitored

natural

atten

uation

1Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

2Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

3Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

4Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Balancing Crite

ria

1No

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

No

2No

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

3No

Yes

Yes

Yes

Yes

Yes

Yes

No

Yes

No

4Yes

No

No

Yes

Yes

Yes

Yes

Yes

Yes

Yes

5No

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

6No

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

7Yes

Yes

Yes

Yes

Yes

Yes

No

No

Yes

Yes

8Yes

No

No

Yes

No

No

No

No

Yes

Yes

No

No

No

Yes

No

No

No

No

Yes

Yes

Protect h

uman

health

, safety, and

the en

vironm

ent

Selected

for further fe

asibility and

cost a

nalysis

Do not present im

pacts o

r risk

s to workers, site

neighbo

rs, and

the commun

ity

durin

g constructio

n and im

plem

entatio

nHa

ve greater practicable capabilitie

s of achieving

standards

Protect b

oth curren

t and

reason

ably anticipated

future land

uses

Rely on the sim

plest m

eans available to achieve cleanup

levels

Cost of R

emed

y

Remed

iate con

taminated

air, so

il, and

water to

attain applicable cleanup

levels

establish

ed und

er Fed

eral or S

tate law or regulation or to

attain site‐specific risk‐

based cleanu

p levels

Control any

sources o

f releases so as to

redu

ce or e

liminate, to

the extent

technically practicable, further re

leases as req

uired to protect hum

an health

and

the en

vironm

ent

Comply with

any

app

licable standard fo

r managem

ent o

f wastes g

enerated

as a

conseq

uence of th

e remed

y

Rely less on containm

ent, passive treatm

ent (i.e. m

onito

red natural atten

uatio

n (M

NA)), and/or institu

tional con

trols to meet cleanup

levels

Use treatm

ent o

r rem

oval to

redu

ce th

e toxicity, m

obility, or v

olum

e of

contam

inants

Achieve cleanu

p levels more qu

ickly

PROJECT NAME: Deluxe Dry Cleaners Orphan SitePROJECT LOCATION: Cheyenne, WyomingPROJECT NUMBER: 24149060

UNIT COST TOTAL COSTDESCRIPTION NOTES UNIT QTY ($) ($)

I. Design Services1. Project Management/Coordination a/ ls 1 $1,500 $1,5002. SVE Pilot Test ls 1 $12,000 $12,0003. SVE System Design/Plans/Specifications/HASP b/ ls 1 $12,000 $12,0004. Permitting ls 1 $3,000 $3,0005. Contract Documents/Bidding/Contracting c/ ls 1 $5,000 $5,000

Subtotal Design Services Costs $33,5006. Contingency (20% of Design Services Costs) $6,700

Total Design Services Costs $40,200

Present Worth Design Services Costs (Year 1) d/ $39,000

II. Construction and Startup Costs1. Construction Costs

a. Mobilization/Demobilization/Setup ls 1 $5,000 $5,000b. Site/Utility Clearance ls 1 $5,000 $5,000c. SVE Vertical Well Installation - 4 wells e/ ls 1 $4,000 $4,000d. SVE Horizontal Well Installation - 3 wells e/ ls 1 $30,000 $30,000e. Vapor Monitoring Points Installation - 6 VMPs f/ ls 1 $6,000 $6,000f. Well vault/pad/well head fittings and instrumentation ea 13 $800 $10,400i. IDW Disposal (drilling cuttings/non-hazardous) ea 7 $150 $1,100h. Trenching, Backfilling and concrete/asphalt patching g/ lf 150 $30 $4,500j. Extraction piping installation g/ lf 150 $15 $2,300

k. SVE System (w/control panel and enclosure) h/ ls 1 $75,000 $75,000m. As-built Survey ls 1 $2,000 $2,000n. Electrical power hookup ls 1 $3,000 $3,000o. Site Cleanup/Restoration ls 1 $1,000 $1,000

Subtotal Construction Costs $149,000

2. Engineering Services and System Startup a. As-built Drawings/O&M Manual/Report ls 1 $5,000 $5,000b. Engineering Oversight (labor and expenses) i/ ls 1 $22,100 $22,100c. System startup/shake down j/ ls 1 $6,700 $6,700d. Project Management/Coordination a/ ls 1 $4,000 $4,000

Subtotal Engineering Services and System Startup Costs $38,000

3. Contingency (20% of Construction and Startup Costs) $37,000

Total Construction and Startup Cost $224,000

PW of Construction and Startup Costs (Year 1) d/ $214,000

TABLE 2OPINION OF PROBABLE COSTS

ALTERNATIVE S1 - SOIL VAPOR EXTRACTION





III. Operation, Maintenance and Monitoring (OMM) Costs (Years 1 through 5)

1. System O&M (Annual)a. Project Management/sub oversight a/ ls 1 $2,000 $2,000b. System O&M Labor/expenses k/ ea 14 $1,000 $14,000c. Electrical Power Costs ls 1 $3,000 $3,000d. Equipment Repair/Replacement ls 1 $1,000 $1,000e. Data review/engineering support ea 7 $1,200 $8,400

Subtotal Annual O&M Cost $28,000

2. Semiannual Monitoring (7 SVE wells + 2 QA/QC samples) a. Project Management/Coordination a/ ls 1 $2,300 $2,300b. Labor - sampling SVE wells l/ ea 2 $5,000 $10,000c. Analyticals: VOCs (total of 7 samples) l/ ea 14 $125 $1,750d. Analyticals: (VOCs) (influent + effluent) l/ ea 4 $125 $500e. Equipment rental (semiannual)/Reimbursable ea 2 $1,000 $2,000f. Remedial System Operation report to WDEQ (Annual) ls 1 $5,000 $5,000g. Regulatory Negotiations/Meetings ls 1 $1,000 $1,000

Subtotal Semiannual Monitoring Cost (Annual) $23,000

3. Contingency (20% of Annual O&M and Monitoring Costs) $10,000

Total Annual OMM Cost $61,000

PW of Annual OMM (Years 1 through 5) d/ $252,000

IV. Site Closure and Decommissioning Costs1. a. Project Management/Coordination a/ ls 1 $7,300 $7,300

b. Abandon piping m/ lf 150 $20 $3,000c. Abandon Recovery and Monitoring Wells m/ ls 1 $6,000 $6,000d. Decommission the SVE system ls 1 $1,500 $2,000e. Labor/expenses ls 1 $6,000 $6,000f. Confirmation Soil Sampling ls 1 $15,000 $15,000g. Regulatory Negotiations/Meetings ls 1 $1,500 $1,500h. Response Action Completion/Closure Report ls 1 $10,000 $10,000

Subtotal Closure Costs $51,000

2. Contingency (20% of Decommissioning Costs) $10,000

Total Annual Closure Costs $61,000

PW of Decommissioning Costs (Year 6) $43,000

PW OF TOTAL PROBABLE COSTS $548,000





Notes and Major Assumptions

a/ Project management and coordinating project related activities.b/ Assumes preparation of Engineering Design (Plans and Specifications) and Implementation Work Plan. No erosion control plan or other

permits are anticipated.c/ Includes preparation of bid documents, bidding, contractor selection, and contract negotations.d/ Present worth costs were estimated based on a net annual discount rate of 5%, assuming year-end distribution. Discount rate

is computed as the difference between the rate at which interest is earned on the account and the annual estimated inflation rate.Net Present Value (NPV) is used only for the purposes of comparison of alternatives.

e/ Assumes installation of 4, two-inch vertical PVC wells to cover an area of approximately 2,800 sf. Wells will be installed to depths of 13 ft, with 10-ft screen. Assumes installation of 3 horizontal two-inch wells at 5 ft bls with 25 feet screen.

f/ Assumes installation of 6 vapor monitoring points (VMPs) for performance monitoring. VMPs will be 1-inch diameter PVC wellsinstalled shallow zone, and screened across different zones.

g/ Includes approximately 250 lf of trenching, and backfilling to install 2-inch SVE piping.h/ Includes an SVE system with a knockout tank, blower, filters, and GAC units for treatment in an enclosure. Includes PLC alarm system.i/ Estimated about 4 weeks of construction field time. Includes labor and expenses for construction oversight and management.j/ Assumes one week of startup time. Includes labor and expenses.k/ Assumes one visit each month for routine O&M plus 2 contingency visits in a year.l/ Includes 8 air samples + one effluent and one influent air sample for VOCs each monitoring event.

m/ Includes system decommissioning and abandonment of piping and wells.- Estimates are based on information currently available and on assumptions listed in this report.- Costs are based on vendor information, contractors' estimate, cost estimation manuals, and past experience. - Abbreviations: ea = each; ls = lump sum; hr = hours; cy = cubic yards; lf = linear feet; Gal - gallons; wk = week; bls = below land surface.

USEPA = United States Environmental Protection Agency- Total Costs are rounded to nearest $100 and the present worth costs are rounded to nearest $1000.



I. Design Services1. Project Management/Coordination a/ ls 1 $2,800 $2,8002. Bench Scale Treatability Test and Slug Testing ls 1 $12,000 $12,0003. ERD System Design/Plans/Specifications/HASP b/ ls 1 $10,000 $10,0004. Well Permitting ls 1 $3,000 $3,0005. Contract Documents/Bidding/Contracting c/ ls 1 $2,500 $2,500

Subtotal Design Services Costs $30,300

6. Contingency (20% of Design Services Costs) $6,100


Present Worth Design Services Costs (Year 1) d/ $35,000

II. Installation Costs1. Installation Costs

a. Mobilization/Demobilization/Setup ls 1 $5,000 $5,000b. Site/Utility Clearance ls 1 $5,000 $5,000c. Injection Well Installation - 16 wells e/ ls 1 $24,000 $24,000d. Performance Well Installation - 6 wells f/ ls 1 $9,000 $9,000e. Well vault/pad/well head fittings ea 22 $500 $11,000f. IDW Disposal (drilling cuttings/non-hazardous) ea 28 $150 $4,200i. Trenching, Backfilling and concrete/asphalt patching g/ lf 250 $30 $7,500h. Injection piping installation g/ lf 250 $15 $3,800j. Installation Oversight (labor and expenses) ls 1 $12,083 $12,100

k. As-built Survey ls 1 $2,000 $2,000o. Site Cleanup/Restoration ls 1 $1,000 $1,000

Subtotal Construction Costs $84,600

3. Contingency (20% of Installation Costs) $16,900

Total Construction and Startup Cost $101,500

PW of Construction and Startup Costs (Year 1) d/ $97,000

III. Injection and Monitoring Costs (Years 1 through 10)

1. Injection Events and Baseline Monitoringa. Project Management a/ ls 1 $12,800 $12,800b. Baseline Monitoring Event and Report (Labor + Expenses) h/ ls 1 $17,400 $17,400c. Injection Activities (Labor + Expenses) i/ ea 3 $12,000 $36,000d. Injection Equipment (pumps, batch tanks, hoses, etc) i/ ls 1 $15,000 $15,000e. Injectate Materials i/ ls 3 $20,000 $60,000

Subtotal Injection and Monitoring Costs (Year 1) $141,200

f. Contingency (20% of Injection Costs) $28,200

Present Worth Injections Costs (Year 1) d/ $162,000


ALTERNATIVE GW-1 - ENHANCED REDUCTIVE DECHLORINATION





2. Source Area Performance Monitoring (4 Years Quarterly, 1 Year Semi-Annually, 5 Years Annually) a. Project Management/Coordination a/ ls 1 $1,100 $1,100b. Performance monitoring event (Labor + Expenses) j/ ea 1 $3,400 $3,400c. Analyticals: VOCs + MNA Parameters j/ ea 1 $3,300 $3,300d. Waste Disposal ea 1 $800 $800e. Monitoring Report ea 1 $3,500 $3,500

Subtotal Performance Monitoring (Event) $12,100

f. Contingency (20% of Monitoring Costs) $2,400

Present Worth Performance Monitoring Costs (Years 1-10) d/ $278,000

3. Downgradient MNA Monitoring (2 Years Quarterly, 2 Year Semi-Annually, 6 Years Annually) a. Project Management/Coordination a/ ls 1 $400 $400b. Performance monitoring event (Labor) k/ ea 1 $2,000 $2,000c. Analyticals: VOCs + MNA Parameters k/ ea 1 $2,100 $2,100

Subtotal MNA Monitoring (Event) $4,500

f. Contingency (20% of Monitoring Costs) $900

Present Worth MNA Monitoring Costs (Years 1-10) d/ $81,000

PW of Injection and Monitoring Costs (Years 1 through 10) d/ $521,000

IV. Site Closure and Decommissioning Costs1. a. Project Management/Coordination a/ ls 1 $3,700 $3,700

b. Abandon piping l/ lf 250 $20 $5,000c. Abandon Injection and Monitoring Wells l/ ls 1 $18,500 $18,500d. Labor/expenses ls 1 $7,000 $7,000f. Regulatory Negotiations/Meetings ls 1 $1,500 $1,500g. Response Action Completion/Closure Report ls 1 $5,000 $5,000




PW of Decommissioning Costs (Year 10) $30,000

PW OF TOTAL PROBABLE COSTS $683,000






a/ Project management and coordinating project related activities.b/ Assumes preparation of Engineering Design (Plans and Specifications) and Implementation Work Plan.c/ Includes preparation of bid documents, bidding, contractor selection, and contract negotations.d/ Present worth costs were estimated based on a net annual discount rate of 5%, assuming year-end distribution. Discount rate


e/ Assumes installation of 16, two-inch vertical PVC wells to depths of 25 ft blsf/ Assumes installation of 6 additional wells for use in performance monitoring. Wells will be two-inch diameter and extend to 25 ft bls. g/ Includes up to 250 lf of trenching, and backfilling to install 2-inch injection piping to allow for remote injection of wells in high traffic areas.h/ Baseline event includes the injection and monitoring well network (37 wells) for VOCs, MNA parameters from 9 wells, and DHC from 3 wells.i/ Injection of approximately 33,000 gallons of HFCS into permanent well network. Assumes no buffer and/or bioaugmentation will be required.j/ Sample collection from 12 source area wells for VOC analysis plus 6 wells for MNA parameters, and 3 wells (semi-annually) for DHCk/ Assumes sampling event and reporting will be combined with performance event. Includes 15 wells for VOCs and 3 wells for MNAl/ Includes abondonment of wells, piping, and removal of surface completions.

- Estimates are based on information currently available and on assumptions listed in this report.- Costs are based on vendor information, contractors' estimate, cost estimation manuals, and past experience. - Abbreviations: ea = each; ls = lump sum; hr = hours; cy = cubic yards; lf = linear feet; Gal - gallons; wk = week; bls = below land surface.




I. Design Services1. Project Management/Coordination a/ ls 1 $300 $3002. Monitoring Program Design/Plans/Specifications/HASP ls 1 $3,000 $3,000

Subtotal Design Services Costs $3,300

3. Contingency (20% of Design Services Costs) $700


Present Worth Design Services Costs (Year 1) b/ $4,000

II. Monitoring Costs (Years 1 through 30)

1. Quarterly MNA Monitoring (2 Years)a. Project Management/Coordination a/ ls 1 $1,100 $1,100b. Monitoring event (Labor + Expenses) c/ ea 1 $3,800 $3,800c. Analyticals: VOCs + MNA Parameters c/ ea 1 $3,200 $3,200d. Waste Disposal ea 1 $800 $800e. Monitoring Report ea 1 $3,000 $3,000

Subtotal Monitoring (Event) $11,900


Present Worth Quarterly MNA Monitoring Costs (Years 1-2) b/ $107,000

2. Semi-annual MNA Monitoring (2 Years)a. Project Management/Coordination a/ ls 1 $1,100 $1,100b. Monitoring event (Labor + Expenses) c/ ea 1 $3,800 $3,800c. Analyticals: VOCs + MNA Parameters c/ ea 1 $3,200 $3,200d. Waste Disposal ea 1 $800 $800e. Monitoring Report ea 1 $3,000 $3,000



Present Worth Semi-Annual MNA Monitoring Costs (Years 3-4) b/ $49,000

3. Annual MNA Monitoring (26 Years)a. Project Management/Coordination a/ ls 1 $800 $800b. Monitoring event (Labor + Expenses) d/ ea 1 $3,800 $3,800c. Analyticals: VOCs d/ ea 1 $1,100 $1,100d. Waste Disposal ea 1 $800 $800e. Monitoring Report ea 1 $2,500 $2,500



Present Worth Annual MNA Monitoring Costs (Years 5-30) b/ $128,000

PW of MNA Monitoring Costs (Years 1 through 30) b/ $284,000


ALTERNATIVE GW-2 - MONITORED NATURAL ATTENUATION




ALTERNATIVE GW-2 - MONITORED NATURAL ATTENUATION

III. Site Closure and Decommissioning Costs1. a. Project Management/Coordination a/ ls 1 $1,800 $1,800

b. Abandon Monitoring Wells e/ ls 1 $7,500 $7,500d. Labor/expenses ls 1 $4,000 $4,000f. Regulatory Negotiations/Meetings ls 1 $1,500 $1,500g. Response Action Completion/Closure Report ls 1 $5,000 $5,000




PW of Decommissioning Costs (Year 30) b/ $6,000

PW OF TOTAL PROBABLE COSTS b/ $294,000


a/ Project management and coordinating project related activities.b/ Present worth costs were estimated based on a net annual discount rate of 5%, assuming year-end distribution. Discount rate


c/ Sample collection from 15 wells for VOC analysis plus 6 wells for MNA parametersd/ Sample collection from 15 wells for VOC analysise/ Includes abondonment of well and removal of surface completions.

- Estimates are based on information currently available and on assumptions listed in this report.- Costs are based on vendor information, contractors' estimate, cost estimation manuals, and past experience. - Abbreviations: ea = each; ls = lump sum; hr = hours; cy = cubic yards; lf = linear feet; Gal - gallons; wk = week; bls = below land surface.
