RECORD OF DECISION (RODS) - Records Collections · 2017. 5. 12. · 2 DECISION SUMMARY In 1994, MCAS Cherry Point was placed on USEPA’s NPL, established under CERCLA §105(a) for

-:Air Station Cherry Point, North CarolinaAugust 2009

1 Declaration

1.1 Site Name and Location

This Record of Decision (ROD) presents the selected remedy for Operable Unit (OU) 14, which consists of one site (Site 90)1 at Marine Corps Air Station (MCAS) Cherry Point, North Carolina. MCAS Cherry Point was placed on the National Priorities List (NPL) on December 16, 1994 (Comprehensive Environmental Response, Compensation, and Liability Information System [CERCLIS] National Superfund database identification number: NC1170027261).

1.2 Statement of Basis and Purpose

The remedy was selected in accordance with the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA), as amended by the Superfund Amendments and Reauthorization Act of 1986 (SARA), and the National Oil and Hazardous Substances Pollution Contingency Plan (NCP). As a result of the NPL listing and pursuant to CERCLA, the United States Environmental Protection Agency (USEPA) Region 4, the North Carolina Department of Environment and Natural Resources (NCDENR), and the United States Department of the Navy (Navy) [consisting of the Naval Facilities Engineering Command (NAVFAC), Mid-Atlantic Division and the MCAS Cherry Point Environmental Affairs Department (EAD)] entered into a Federal Facility Agreement (FFA) for MCAS Cherry Point in 2005. The primary purpose of the FFA is to ensure that the environmental impacts associated with past and present activities at MCAS Cherry Point are thoroughly investigated. The Navy’s Environmental Restoration Program (ERP) is responsible for ensuring that appropriate CERCLA response alternatives are developed and implemented as necessary to protect public health, welfare, and the environment. No enforcement activities have been recorded at OU14.

The Navy and USEPA Region 4 jointly selected the remedy for OU14, with the concurrence of NCDENR. The Navy is the lead agency and provides funding for site cleanup at MCAS Cherry Point under its ERP. This decision is based on information contained in the Administrative Record2 for the site. Information not specifically summarized in this ROD but contained in the Administrative Record has been considered and is relevant to the selection of the remedy at OU14. Thus, the ROD is based upon and relies upon the entire Administrative Record file for the site in making the remedy selection decision.

1 Operable Unit 14 and Site 90 are synonymous, and are referred to in the remainder of this document as ―OU14‖. 2 Bold blue text identifies detailed site information available in the Administrative Record and listed in the References table in Section 4.2.

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1 DECLARATION

1.3 Scope and Role of Response Action

OU14 is one of nine OUs that have been identified at MCAS Cherry Point. CERCLA environmental investigations began in 1983 with an Initial Assessment Study (IAS). Additional investigations and remedial actions at other OUs are ongoing. The Site

Management Plan (SMP) for MCAS Cherry Point further details the schedule for CERCLA remediation activities and is updated annually.

OU14 consists of a chlorinated volatile organic compound (VOC) groundwater plume that underlies the area including and surrounding Building 130. OU14 is isolated hydraulically from an adjacent operable unit, OU1, by a groundwater flow divide. The known contamination at OU14 did not originate or migrate from another OU or site, nor does contamination originating at OU14 extend to within the boundaries of another OU or site. This ROD documents the selected remedial action for OU14 and does not include or affect any other sites at the facility.

1.4 Selected Remedy

Assessment of the Site

As a result of environmental investigations completed under CERCLA at OU14, chlorinated VOCs were identified in groundwater at concentrations that pose a potential threat to human health. A remedial action is required to return the aquifer to beneficial use because the groundwater is considered a potential source of drinking water. The response action presented in this ROD is necessary to protect the public heath, welfare, and the environment from actual or threatened releases of hazardous substances from the site.

No significant chlorinated VOC contamination was found at OU14 in soil, sediment, or surface water, and no further action is required for these media. The no further action determination for these media is addressed by this ROD, which is the final ROD for OU14.

The selected remedy for groundwater contamination at OU14 is Monitored Natural Attenuation (MNA) and Land Use Controls (LUCs). MNA involves the collection of monitoring data to verify the effectiveness of naturally occurring processes to reduce contaminant concentrations over time. LUCs maintain groundwater and associated property-use restrictions until the contaminant concentrations in groundwater have been reduced to levels that allow for unlimited use/ unrestricted exposure (UU/UE).

Statutory Determinations

The selected remedy meets the statutory requirements and is protective of human health and the environment, complies with Federal and State regulations that are applicable or relevant and appropriate to the remedial action, is cost-effective, and uses permanent solutions and alternative treatment technologies to the maximum extent practicable. Although the selected remedy for groundwater does not strictly meet the statutory preference for treatment as a principle element, the selected remedy represents the maximum extent to which permanent solutions and treatment are practicable at OU14. Because of the low volume and concentrations of COCs present, treatment would not be cost effective. Since the remedy will result in pollutants or contaminants remaining onsite in groundwater above levels that allow for UU/UE, a statutory review will be conducted

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1 DECLARATION

every 5 years after the initiation of remedial action to ensure the remedy is protective of human health and the environment.

1.5 Data Certification Checklist

The following information was considered in the selection of the remedy for OU14:

Current and reasonably anticipated future land use assumptions and current and potential future beneficial uses of groundwater (Section 2.4)

Chemicals of concern (COCs) and their respective concentrations (Section 2.5)

Baseline risk represented by the COCs (Section 2.5)

The absence of principal threat waste identified at OU14 (Section 2.6)

Cleanup levels established for COCs and the basis for these levels (Section 2.7)

Estimated capital, annual operation and maintenance, total present-worth costs, discount rate, and the number of years over which the remedy cost estimates are projected (Section 2.8)

Key factors that led to selecting the remedy (Section 2.9.1)

Potential land and groundwater use that will be available at the site as a result of the selected remedy (Section 2.9.3)

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DECLARATION

1.6 Authorizing Signatures This ROD presents the Selected Remedy at OU14, Site 90, at MCAS Cherry Point, located in Craven County, North Carolina.

D.A. Denn Date Colonel, U.5. Marine Corps Commanding Officer MCAS Cherry Point

The North Carolina Department of the Environment and Natural Resources concurs:

irectorDexter R. Matthews, Date Division of Waste Management NCDENR

- _. - _. . .. ..... _ .. - ------~_. ~- -~ ~

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LegendCJ au Boundary

BuildingsD Runway• RoadC-i Base Boundary

2 Decision Summary

2.1 Site Description and History

MCAS Cherry Point is a 13,164-acre military installation located in southeastern Craven County, North Carolina, just north of the town of Havelock. MCAS Cherry Point is bounded to the north by the Neuse River, to the east by Hancock Creek, to the south by North Carolina Highway 101, and by an irregular boundary approximately three quarters of a mile west of Slocum Creek (Figure 1). Commissioned in 1942, MCAS Cherry Point maintains facilities for training and supporting the Atlantic Fleet Marine Force aviation units and is designated as a primary aviation supply point. Surrounding areas include primarily commercial and residential development and public land (Croatan National Forest).

FIGURE 1

OU14 Location Map

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2 DECISION SUMMARY

In 1994, MCAS Cherry Point was placed on USEPA’s NPL, established under CERCLA §105(a) for sites contaminated by releases of hazardous substances. In May 2005, a FFA was executed for MCAS Cherry Point that developed a course of action for future work requirements at each site, and OU14 was included in order to address chlorinated VOC groundwater contamination. The portion of OU14 including and surrounding Building 130 is designated under the Navy’s ERP as Site 90.

OU14 (Site 90) is located in the west-central portion of the MCAS Cherry Point flight-line complex (Figure 1), and consists of a broad expanse of concrete tarmac, buildings, taxiways, and some grassy areas adjacent to Runway 14L (Figure 2). OU14 includes Building 130, a large aircraft hangar containing two large aircraft bays, storage rooms, and administrative offices. From Building 130, OU14 extends approximately 5,000 feet north-northwest to an unnamed stream adjacent to Runway 14L.

There is no known documentation concerning the disposal, spill, or release of chlorinated VOCs at OU14. The most likely former source areas of the contamination include the Building 130 area (specifically the Building 130 Wash Rack), the C-130 Wash Rack, the Building 4075 area (which includes a former waste solvent underground storage tank [UST], a hazardous waste aboveground storage tank [AST], and a wash rack), and the Former Refueling Station near Building 4495 (Figure 2). The source areas are inferred based on the distribution of contamination.

The Building 130 Wash Rack was used to wash aircraft and related equipment since the early 1940s, and is currently used to flush aircraft fuel drop tanks with water. Solvents in rinse water that were drained from the wash racks to the industrial sewer system were most likely released to the subsurface through leaking sewer pipes. The older sections of the industrial sewer system are continually being repaired.

An extensive network of abandoned underground fuel pipelines that connected Tank Farm A to various buildings and aircraft refueling stations and several former USTs have contributed to petroleum-related contamination in soil and groundwater at OU14. Petroleum-related contamination is being addressed under the MCAS Cherry Point UST (Petroleum Cleanup) Program and is not within the jurisdiction of the ERP.

More-detailed descriptions of OU14 and the environmental history are summarized in the OU14 Remedial Investigation and the OU14 Feasibility Study. These and other historical documents regarding OU14 are part of the Administrative Record for MCAS Cherry Point.

2.2 Previous Investigations

Beginning in 1994, several environmental investigations have been conducted at OU14 and are summarized in Table 1. The most comprehensive environmental investigation was the OU14 Remedial Investigation (RI), which was designed to delineate the nature and extent of contamination that poses a potential threat to human health and the environment. The total numbers of samples per media (soil, groundwater, sediment, and surface water) collected during the OU14 RI are summarized in Table 2. Details of the investigation procedures and sampling design are summarized in the OU14 RI.

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o

LegendApproximate ERP Site 90 BoundaryApproximate extent of area treated ~!1

,-,J by the MCAS Cherry Point UST Program's .."Building 4075 Treatment System" :.

- Surface Water

UST ProgramBldgs 130 & 3996Treatment System

(Air Sparge, SVE andFP Recovery)

Aircraft Washrack

2 DECISION SUMMARY

FIGURE 2

OU14 Site Features

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2 DECISION SUMMARY

TABLE 1

Previous Studies and Investigations

Previous Study/ Investigation* Date Investigation Activities

Base Realignment 1994 to Soil and groundwater samples indicated petroleum contamination in and Closure (BRAC) 2000 soil and groundwater in and around OU14. Petroleum free product and UST Program was found to occur at the groundwater table. A quantitative human Investigations health risk assessment was performed for site workers using the soil

and groundwater data. A Corrective Action Plan (CAP) was developed for the petroleum contamination and an automated free product recovery system and Air Sparge (AS) and Soil Vapor Extraction (SVE) remedial system with MNA were installed in 2001.

OU1 RI 2002 Groundwater samples collected in what is now OU14 as part of the RI for the adjacent Operable Unit 1 (OU1) revealed the presence of chlorinated VOCs in groundwater near the Building 130 Wash Rack. Led to the designation of OU14.

OU14 RI 2008 Soil, groundwater, surface water, and sediment samples were collected for analysis of VOCs, inorganic constituents, and natural attenuation indicator parameters (groundwater only). In soil, only petroleum-related contamination was observed, with the highest concentrations found in the area of Tank Farm A. Chlorinated VOCs and inorganics were only observed above the North Carolina Groundwater Quality Standard (NCGWQS) within groundwater of the surficial aquifer. No constituents were observed in sediment and surface water above screening levels. Inorganic constituents detected in groundwater were consistent with natural, background concentrations. Potential human health risks from groundwater were identified for future adult residents, future child residents, and lifetime residents. The results of groundwater data screening for potential vapor intrusion impacts showed no indication of a need for mitigation of vapor issues for existing buildings. No potential ecological risks were identified.

Feasibility Study (FS) 2009 The FS was performed to develop and evaluate remedial alternatives to mitigate potential human health risks associated with the chlorinated VOC groundwater contamination. The alternatives retained for detailed comparative analysis were: (1) MNA and LUCs, (2) Biosparge, MNA, and LUCs, and (3) Enhanced Reductive Dechlorination (ERD), MNA, and LUCs.

Proposed Plan (PP) 2009 Provided the Preferred Alternative for OU14 and invited the public to review and comment prior to the final decision.

* The documents listed are available in the Administrative Record and provide detailed information used to support remedy selection at OU14. See Section 4.2 for the complete titles and reference information for the documents listed in this table.

TABLE 2

Total Numbers of Samples Collected During the OU14 Remedial Investigation

Media Number of Samples

Soil 28

Surface Water 7

Sediment 7

Groundwater 217

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2 DECISION SUMMARY

2.3 Site Characteristics

OU14 and the surrounding area includes a large paved area of concrete or asphalt used for aircraft and associated vehicle traffic, several buildings and hangars, a runway, an unnamed stream, and some small grassed areas (Figure 2). The unnamed stream parallels the southern side of Runway 14L, and receives surface water drainage from portions of OU14 before crossing under the runway and eventually joining Mill Creek to the north. The topography of the site is relatively flat with a gentle slope to the north, and an approximate average ground elevation of 25 feet above mean sea level.

The hydrogeology beneath OU14 consists of a water table aquifer (surficial aquifer) and several deeper aquifers with intervening confining units: in descending order, the Yorktown, Pungo River, and Castle Hayne aquifers (Figure 3). Since chlorinated VOC contamination beneath OU14 was found to only occur within the surficial aquifer, investigation activities were focused on the surficial and Yorktown aquifers.

The surficial aquifer beneath OU14 consists of unconsolidated sands that are fine- to medium-grained in size with some silts and clay. The aquifer was subdivided into an upper and lower zone for evaluation due to the relative thickness of the aquifer (approximately 40 feet) and some minor differences in aquifer properties. The upper surficial aquifer is generally more fine-grained relative to the lower surficial aquifer and extends from approximately 12 feet below ground surface [bgs] to a depth of 25 to 30 feet bgs. The lower surficial aquifer extends from approximately 30 feet bgs to the top of the Yorktown confining unit at a depth of 50 to 60 feet bgs. The horizontal groundwater flow directions within the surficial aquifer are generally towards the north-northwest and north towards Mill Creek, similar to topographic slope. The average groundwater velocity is estimated to be between 25 and 30 feet per year. The unnamed stream also receives some shallow groundwater discharge but does not act as a hydraulic barrier. The vertical hydraulic gradient between the surficial aquifer and underlying Yorktown aquifer is downwards.

Petroleum-related compounds were the only chemicals detected above regulatory standards in soil beneath OU14. The MCAS Cherry Point UST Program is responsible for addressing any petroleum-related contamination at the site. These compounds are not addressed under CERCLA or by this ROD. No chlorinated VOC soil contamination was observed; therefore, soil is not a continuing source of chlorinated VOC contamination in groundwater.

Groundwater contamination at OU14 is defined by the spatial extent of chlorinated VOC concentrations that exceed their respective NCGWQS. Several plumes of chlorinated VOCs

were found to occur within the surficial aquifer, which migrate in the north-northwest direction of groundwater flow (Figure 4). Based on the distribution of contamination, potential historical source areas appear to include the Building 130 area and wash rack, the Building 4075 area, the C-130 wash rack, and the Former Refueling Station near Building 4495.

No chlorinated VOCs were found in the underlying Yorktown aquifer. The maximum concentrations of the chlorinated VOCs trichloroethene (TCE), cis-1,2-dichloroethene (cis-1,2-DCE), and vinyl chloride observed in the upper surficial aquifer were 180, 30, and 70 micrograms per liter (µg/L), respectively, and 19, 180, and 2.3 µg/L in the lower surficial aquifer, respectively (above the NCGWQS of 2.8, 70, and 0.015 µg/L, respectively). Based on the suspected timeframe of the releases of chlorinated VOCs at OU14 (approximately 30 to 60 years ago) and the specific chlorinated VOC compounds currently present in

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2 DECISION SUMMARY

groundwater, the various plumes can be characterized as plumes that have undergone significant biodegradation and natural attenuation. TCE is biodegraded primarily by naturally-occurring, dechlorinating bacteria via a process called reductive dechlorination under anaerobic conditions in the aquifer. The chlorinated VOC plumes at OU14 contain relatively low detected concentrations of TCE in conjunction with the widespread presence of TCE daughter products such as 1,2-DCE and vinyl chloride.

Further evidence of natural biodegradation of chlorinated VOCs at OU14 was obtained during the RI through the analyses of selected groundwater samples for several natural

attenuation evaluation parameters and analytes, including pH, oxidation-reduction potential (ORP), total organic carbon (TOC), dissolved oxygen (DO), nitrate/nitrite, iron II/III, and sulfate/sulfide. These data were used to further evaluate whether biodegradation of the chlorinated VOCs in groundwater is occurring naturally under anaerobic conditions at OU14. The results supported the conclusion that sufficient to ideal conditions were present in the surficial aquifer at OU14 for anaerobic biodegradation.

The naturally-occurring inorganic constituents arsenic, iron, and manganese were detected in the surficial aquifer at concentrations exceeding their respective NCGWQS, but at concentrations that were generally consistent with the range of natural background conditions at MCAS Cherry Point. It was determined that these constituents were not

COCs at OU14.

Numerous petroleum-related compounds, including benzene, and petroleum free product were found to be widespread in the surficial aquifer. These constituents are being addressed by the MCAS Cherry Point UST Program, and several remediation systems are currently active under the UST Program at OU14 to remove the free product and treat petroleumrelated contamination in soil and groundwater. The petroleum–related compounds likely serve as a carbon source for the naturally-occurring dechlorinating bacteria and facilitate the biodegradation of the chlorinated VOCs.

No chlorinated VOCs were observed in surface water or sediment above regulatory standards in the unnamed stream located just south of Runway 14L.

Predictive modeling was conducted as part of the OU14 RI to estimate source area contamination reduction required to prevent impacts to potential downgradient groundwater receptors, namely the unnamed stream. Groundwater fate and transport modeling was performed for OU14 using BIOCHLOR Version 2.2 and Natural Attenuation Software (NAS) Version 2.20. The results indicated that the TCE, cis-1,2-DCE, vinyl chloride, and other chlorinated VOCs found in upgradient areas of OU14 will not reach the unnamed stream at concentrations above regulatory standards due to biodegradation and other natural attenuation mechanisms. All modeling parameters and results can be found in the OU14 RI that is part of the Administrative Record for MCAS Cherry Point.

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GroundwaterFlow DireciiOn

Volatilization

C.137irCraft Was Rack

, Ta7annABuilding

250

I

Runway

.'. .LEGEND

'Y Groundwater Table Elevation

Groundwater Flow Direction

o Surficial Aquifer

_ Yor1<.town Confining Unit

Yorktown Aquifer

Approximate Dissolved Plume Extents

2 DECISION SUMMARY

FIGURE 3

Conceptual Site Model

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!336j1~56GW06

/ 56GW12

24

03

LegendSLow• er Surficial A .~ ~oprpktown AqUifer~~~~t~Onitoring Well

_ er Surficial A. ring Welluppe~~~ace Water qUlfer Monitoring Well

.... n Lower Surficial A ..... >2.8 ~g/L, TCE U quoter Isoconcentraf~OO w- l~ WM

CJ

~g/L, TCE Upper - >2.8 ~g/L, TCE Lo~~5 ~rCJ>. ~glL, VC Upper ~

100 ~g/L, CVOC r - >0.015• >200 ~g/L CVO sUpper r.= >100 ~glL, VC Lo~r.... G ' Cs Upper. ~glL, CVOCs Low

eneral Ground >200 ~g/L, CVOCs L er 0water Flow O. . ower ..:~~~~;;;~Irectlon -

2 DECISION SUMMARY

FIGURE 4

TCE, Vinyl Chloride, and Total Chlorinated VOCs; Upper and Lower Surficial Aquifers

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2 DECISION SUMMARY

2.4 Current and Potential Future Land and Resources Uses

MCAS Cherry Point is located just north of Havelock, North Carolina. The area surrounding the installation consists of commercial and residential developments, waterways, and the Croatan National Forest. Current land use at the installation includes military operations, training, maintenance and production, supply, medical administration, troop and family housing, community support, recreation, and utilities. MCAS Cherry Point is expected to remain as an active military installation in the foreseeable future.

OU14 is currently used for industrial purposes, primarily related to the storage, maintenance, re-fueling, and as a taxiway for aircraft and associated vehicles (Figure 5). Current land uses at the site and installation are reasonably anticipated to continue indefinitely to support the mission of the facility.

FIGURE 5

OU14 Site Photograph in 2007 View to Northwest

Groundwater from the Caste Hayne aquifer is used as a potable resource at MCAS Cherry Point for domestic and industrial supply and is classified by the State of North Carolina as an existing or potential source of drinking water. Only groundwater within the surficial aquifer has been impacted by OU14 activities, and the OU14 groundwater contamination does not pose a threat to the Castle Hayne aquifer. The surficial aquifer is not currently an active groundwater resource and is not anticipated to be used as a source of drinking water

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2 DECISION SUMMARY

at MCAS Cherry Point. Under North Carolina’s groundwater classification, the surficial aquifer is considered as Class GA, a potential source of drinking water; therefore, the Navy considered remedial alternatives to restore the aquifer to beneficial use.

There are no surface water resources used as potable water supplies in or around MCAS Cherry Point. The surface water bodies in and around the Air Station are classified by the State of North Carolina as either Class C (freshwaters protected for secondary recreation, fishing, and aquatic life) or Class SC (saltwaters protected for secondary recreation, fishing, and aquatic life).

2.5 Summary of Site Risks

The potential historical sources of contamination at OU14 include wash racks, a former waste solvent underground storage tank, a hazardous waste aboveground storage tank, a former refueling station, jet fuel distribution systems, and industrial, stormwater, and sanitary sewer lines. The primary transport mechanism of contamination at the site included infiltration of contamination from leaky pipes and drains through unsaturated soil to groundwater, which further migrated in groundwater downgradient as a dissolved-phase plume.

OU14 was quantitatively evaluated for potential risks to human health and the environment as part of the RI. Groundwater and indoor air vapor were determined to be the only media with contamination posing potentially unacceptable risks to human health or the environment at OU14. The RI report provides a more-detailed analysis and evaluation. A general summary of the site risks calculated to be above regulatory thresholds is discussed below.

2.5.1 Human Health Risk Assessment

Human health risks were quantitatively evaluated for potential human receptors exposed to groundwater, surface water, and sediment using reasonable maximum exposure (RME) and central tendency exposure (CTE) point concentrations. The RME assumes the highest level of human exposure that could reasonably be expected to occur, whereas the CTE scenario reflects a more realistic human exposure to levels (average concentrations).

The potential for non-cancer hazards is evaluated by determining the ratio of exposure to toxicity or the hazard quotient (HQ). A HQ greater than 1 indicates that a receptor’s exposures may present an unacceptable non-cancer hazard. In addition, a hazard index (HI) is generated by adding the HQs for all constituents that affect the same target organ or cause adverse health effects within a medium or across all media to which an individual may reasonably be exposed. HI values greater than 1 indicate the potential for unacceptable noncancer hazards due to exposure.

For known or suspected carcinogens, acceptable exposure levels generally are concentration levels that represent an excess upper bound lifetime cancer risk to an individual of between 10-4 (a 1 in 10,000 chance of developing cancer) and 10-6 (a 1 in 1,000,000 chance of developing cancer) using information on the relationship between dose and response. The 10-6 risk level is used as the point of departure for determining performance standards for alternatives when Applicable or Relevant and Appropriate Requirements (ARARs) are not available or are not sufficiently protective because of the presence of multiple contaminants at a site or multiple pathways of exposure.

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2 DECISION SUMMARY

Chlorinated VOC contamination was below regulatory standards in soil and there are no exposure pathways to soil at OU14 (potential source areas are covered by buildings and concrete). Therefore, risk due to exposure to soil was not evaluated in the Human Health Risk Assessment (HHRA). To assess the potential for leaching of chlorinated VOCs from soil to groundwater, soil data were compared with North Carolina Soil Screening Levels (NC SSLs) for the protection of groundwater. Chlorinated VOC concentrations did not exceed any NC SSLs. No chlorinated VOCs are identified as COCs in soil at OU14.

Potential risks were identified for exposure to groundwater from the surficial aquifer by a future adult resident, future child resident, and lifetime resident. The contaminant posing unacceptable risk for the future and lifetime adult and child resident receptors driving the remedial action addressed by this ROD is the chlorinated VOC vinyl chloride. Although arsenic, iron, and manganese also contributed to the potential risks, these constituents were excluded as COCs because they are naturally-occurring constituents that were found at concentrations generally consistent with background conditions at MCAS Cherry Point, and because they are not related to historical contaminant releases that are regulated under CERCLA. Benzene also contributed to potential risk, but is not retained as a COC because the MCAS Cherry Point UST Program is responsible for addressing benzene and all other petroleum-related compounds. Table 3 presents a summary of the receptors with risk and hazard estimates above regulatory levels.

Although unacceptable risk to potential future residents through exposure to groundwater in the surficial aquifer was identified in the HHRA, this exposure scenario is unlikely to occur. OU14 is an active flightline area at MCAS Cherry Point, and there are no plans or likely future plans to change the industrial land use at the site to residential. In addition, even if the area was to become residential, human exposure to groundwater from the surficial aquifer is unlikely. Drinking water supplies in the area are typically derived from a depth greater than 190 feet bgs from aquifers that are separated by multiple clay confining units that restrict the downward migration of contaminants. Groundwater in the surficial aquifer also has elevated concentrations of naturally occurring inorganic constituents that make the groundwater quality poor for potable water use.

The HHRA also included a vapor intrusion screening evaluation to assess impacts from VOCs in the groundwater to indoor air. The vapor intrusion evaluation results showed no indication of the need to mitigate vapor issues resulting from chlorinated VOCs for existing buildings under current industrial exposure scenarios. Conservative estimates of indoor air concentrations were calculated by using the concentrations in groundwater of the surficial aquifer and comparing them to regulatory standards. The results indicated a need for further evaluation of the vapor intrusion pathway in the event that new buildings are constructed or if existing buildings are changed significantly (physical structure, occupancy, or use). Therefore, the potential for vapor intrusion will be considered in the future, if necessary, prior to new building construction or major building modifications (structure, occupancy, or use). The selected remedy for chlorinated VOCs present in groundwater will reduce the potential for vapor intrusion impacts.

The HHRA results indicated that there are no cancer risks or non-cancer hazards above acceptable ranges from exposure to surface water and sediment.

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2 DECISION SUMMARY

TABLE 3

Summary of Potential Human Health Risks* Cancer Non Cancer

RME RME Non CTE Non Toxicity Toxicity Cancer Cancer CTE Cancer Cancer Factor (CSF) Factor (RfD)

Receptor Media Pathway Chemical of Concern EPC (µg/L) Risk Risk (HI) Risk Risk (HI) mg/kg day 1 mg/kg day

Future Adult Resident

Groundwater Ingestion

Total Receptor

Iron

-

1.3x10 -4

-

NA

NA

1.2

4.2

NA

NA

0.84

2.9

N/A

-

0.3

-

Iron 1.3x10 -4

NA 2.8 NA 2.8 N/A 0.3

Arsenic 6.4 NA 1.4 NA 1.4 1.5 3.0x10 -4

Future Child Resident

Groundwater

Ingestion Benzene

Manganese

82

410

NA

NA

1.3

1.3

NA

NA

1.3

1.3

5.5x10 -2

N/A

4.0x10 -3

2.0x10 -2

Inhalation/Dermal Benzene 82 NA 1.3 NA 1.3 2.7x10 -2

8.6x10 -3

Total Receptor - - NA 9.8 NA 9.8 - -

Arsenic 6.4 1.4x10 -4

NA 7.6x10 -5

NA 1.5 3.0x10 -4

Vinyl Chloride 5.8 1.3x10 -4

NA 6.9x10 -5

NA 1.5 3.0x10 -3

Benzene 82 6.8x10 -5

NA 3.6x10 -5

NA 5.5x10 -2

4.0x10 -3

Ingestion PCE 1 8.1x10

-6 NA 4.3x10

-6 NA 0.54 1.0x10

-2

Future Child 1,2-DCA 3.8 5.2x10 -6

NA 2.8x10 -6

NA 9.1x10 -2

2.0x10 -2

and Adult Lifetime

Groundwater TCE

Vinyl Chloride

15

5.8

2.4x10 -6

1.3x10 -4

NA

NA

1.3x10 -6

6.9x10 -5

NA

NA

1.1x10 -2

3.1x10 -2

6.0x10 -3

2.9x10 -2

Resident Benzene 82 6.8x10 -5

NA 3.6x10 -5

NA 2.7x10 -2

8.6x10 -3

Inhalation/Dermal PCE 1 8.1x10 -6

NA 4.3x10 -6

NA 2.1x10 -2

8.0x10 -2

1,2-DCA 3.8 5.2x10 -6

NA 2.8x10 -6

NA 9.1x10 -2

1.4x10 -3

TCE 15 2.4x10 -6

NA 1.3x10 -6

NA 6.0x10 -3

N/A

Total Receptor - - 5.7x10 -4

NA 3.0x10 -4

NA - -

Future Construction Worker

Groundwater Total Receptor No Individual COC

- 7.9x10 -6

2.6** 4.3x10 -6

1.5** - -

Potential unacceptable risks are shaded yellow. EPC = Exposure Point Concentration NA = Not Applicable RME = Reasonable Maximum Exposure CTE = Central Tendency Exposure HI = Hazard Index PCE = Tetrachloroethene 1,2-DCA = 1,2-dichloroethane TCE = Trichloroethene µg/L = micrograms per liter *More-detailed information related to the human health risk assessment is included in the OU14 Remedial Investigation included in the Administrative Record. **While this HI exceeds USEPA’s benchmark of 1, no individual constituents or target organs had HIs above 1. In addition, the carcinogenic risk to a future construction worker from exposure to surficial aquifer groundwater is within USEPA’s target range. Therefore, there were no calculated hazards or risks to a future construction worker above USEPA’s benchmark levels.

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2 DECISION SUMMARY

The RI specifies the HHRA assumptions and uncertainties inherent in the risk assessment process due to the number of samples collected or their location, the literature-based values used to calculate risk, and risk characterization across multiple media and exposure pathways.

2.5.2 Screening-level Ecological Risk Assessment

A Screening-level Ecological Risk Assessment (SERA) was conducted for the unnamed stream at OU14, and included the evaluation of the environmental setting, chemical fate and transport, ecotoxicity and potential ecological receptors, and complete exposure pathways. The SERA includes Steps 1 and 2 of the eight-step USEPA ERA process. Potentially complete exposure pathways were identified for lower trophic-level aquatic receptor populations such as aquatic plants, fish, and macro-invertebrates (e.g., mayflies, aquatic worms, crustaceans, and mollusks).

Potential risks to ecological receptors from exposure to all detected contaminants were calculated using conservative exposure assumptions. The SERA concluded that ecological risks are negligible and no further ecological investigation or risk analysis is warranted for the unnamed stream at OU14. Therefore, Steps 3 through 7 were not completed.

The RI specifies the SERA assumptions and uncertainties inherent in the risk assessment process due to the number of samples collected or their location, the literature-based values used to calculate risk, and risk characterization across multiple media and exposure pathways.

2.5.3 Basis for Action

Based on the results of the HHRA, exposure to groundwater by potential future residents at OU14 poses an unacceptable risk to human health due to the presence of vinyl chloride.

All aquifers are classified by the State of North Carolina as a potential source of drinking water. As per the State’s anti-degradation policy, NCDENR requires the restoration of groundwater to beneficial use and for the protection of human health. Consequently, NCDENR identifies the NCGWQS as an applicable requirement for groundwater remediation. Details of the ARARs are included in Appendix A and provided in the OU14 FS, included in the Administrative Record for MCAS Cherry Point.

The COCs in groundwater retained at OU14 that require a response action are summarized in Table 4.

It is the current judgment of the Navy and USEPA, in concurrence with NCDENR, that the Selected Remedy in this ROD is necessary to protect public health or welfare or the environment from actual or threatened releases of hazardous substances into the environment.

2.6 Principal Threat Waste

Principal threat wastes are generally considered to be hazardous or highly toxic source materials that result in ongoing contamination to surrounding media, generally cannot be reliably contained, or present a significant risk to human health or the environment should exposure occur. Although a remedial response action is necessary at OU14, based on the lack of significant source materials, the low chlorinated VOC concentrations observed in

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groundwater, the results of the human health and ecological risk assessments, and the unrealistic exposure scenarios to COC-impacted groundwater, there are no wastes that constitute a principal threat at OU14.

2.7 Remedial Action Objectives Remedial action objectives are established based on attainment of regulatory requirements, standards, and guidance; contaminated media; chemicals of concern; potential receptors and exposure scenarios; and human health and ecological risks. The following remedial action objectives were developed for the groundwater contamination at OU14 to address the potential human health risk associated with future potable use of groundwater:

• Prevent human exposure to groundwater of the surficial aquifer that contains COCs above cleanup levels.

• Restore groundwater quality at OU14 to the NCGWQS and maximum contaminant level (MCL) standards based on the classification of the aquifer as a potential source of drinking water (Class GA or Class GSA) under 15A NCAC 02L.0201.

• Achieve suitability of OU14 groundwater for unlimited use with a reasonable approach and within a reasonable timeframe.

• Prevent migration or discharge of COCs in groundwater of the surficial aquifer to sediment and surface water in the unnamed stream at levels that would cause unacceptable risks to human or ecological receptors.

• Prevent unacceptable risks to human receptors from exposure to indoor air vapors that result from subsurface COCs.

Specific remediation goals (cleanup levels) were developed to meet these remedial action objectives as presented in Table 4. The remediation goals selected for the site were the NCGWQS, the most conservative chemical-specific ARAR.

TABLE 4 Performance Standards

Groundwater Performance Chemical of Concern Standard (µg/L) Basis

1,1-Dichloroethane (1,1-DCA) 70 NC2L 1,2-Dichloroethane (1,2-DCA) 0.38 NC2L

Chloromethane 2.6 NC2L cis-1,2-Dichloroethene (cis-1,2-DCE) 70 NC2L

Methylene Chloride 4.6 NC2L Tetrachloroethene (PCE) 0.7 NC2L

Trichloroethene (TCE) 2.8 NC2L Vinyl Chloride 0.015 NC2L

NC2L – North Carolina 2L Groundwater Standard µg/L – micrograms per liter

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2.8 Description and Evaluation of Remedial Alternatives

To address the protection of groundwater and potential human exposure to groundwater, a preliminary screening of General Response Actions (GRAs) and remedial technologies was completed to refine the remedy selection process, as detailed in the OU14 FS. Following the preliminary screening, five remedial alternatives were developed for detailed evaluation:

Alternative 1 – No Action

Alternative 2 – LUCs

Alternative 3 – MNA and LUCs

Alternative 4 – Biosparge, MNA, and LUCs

Alternative 5 – Enhanced Reductive Dechlorination (ERD), MNA, and LUCs

2.8.1 Description of Remedial Alternatives

Table 5 provides the major components, details, and costs of each remedial alternative identified for OU14. Each remedial alternative, with the exception of the no-action alternative, was developed to meet the remedial action objectives (RAOs). Consistent with the NCP, a no action alternative was evaluated as a baseline for the comparative analysis.

TABLE 5

Remedial Alternatives

Alternative Components Details Cost

1. No Action Existing - No action No cost groundwater

No action for COCs in - Natural attenuation would reduce chemical groundwater and no concentrations over time, but no monitoring of restriction on activities. groundwater conditions is conducted

2. Land Use Controls (LUCs)

Prevents human

LUCs - LUCs to restrict access to Surficial Aquifer groundwater within potentially contaminated areas until the remediation goals are achieved

Capital Cost: $11,000

Present Value of exposure to COCs in groundwater and indoor air vapor by placing restrictions on land use (including underlying aquifer resources).

- LUCs to ensure that the potential for vapor intrusion is evaluated during new building construction or the modification of existing structures within potentially contaminated areas

Future, Annual Operations and Maintenance (O&M) Costs: $695,000

Total Present-Worth Cost: $706,000

Discount Rate: 2.7%

Assumed timeframe: 100 years

3. Monitored Natural Biodegradation - Installation of additional monitoring wells and periodic Capital Cost: Attenuation (MNA) and other natural groundwater monitoring for COCs and natural $413,000 and LUCs attenuation attenuation parameters until the remediation goals are

mechanisms to achieved Present Value of Groundwater remove COCs Future, Annual O&M monitoring to assess from groundwater - LUCs to restrict access to Surficial Aquifer Costs: $1,663,000

COC concentrations groundwater within potentially contaminated areas until until remediation goals Periodic the remediation goals are achieved Total Present

have been met via groundwater Worth Cost:

natural attenuation sampling - LUCs to ensure that the potential for vapor intrusion $2,076,000

processes. Also is evaluated during new building construction or the

includes LUCs. LUCs modification of existing structures within potentially Discount Rate: 2.7%

contaminated areas Assumed timeframe: 100 years

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2 DECISION SUMMARY

TABLE 5

Remedial Alternatives

Alternative Components Details Cost

4. Biosparge, MNA, Biosparge system - Installation of biosparge system to inject air into Capital Cost: and LUCs to enhance natural groundwater in the areas with the highest COC $1,792,000

biodegradation concentrations via a network of horizontal wells to Injection of air into the processes and induce mass transfer (volatilization) of COCs from Present Value of groundwater to remove COCs groundwater and to enhance biodegradation. MNA Future, Annual stimulate the from groundwater would be employed to address the remaining areas of O&M Costs: biodegradation of groundwater contamination. $3,284,000 COCs and to strip Periodic COCs out of the groundwater - Installation of additional monitoring wells and periodic Total Present

groundwater. Also sampling groundwater monitoring for COCs and natural Worth Cost:

incorporates MNA and attenuation parameters until the remediation goals are $5,076,000

LUCs. LUCs achieved Discount Rate: 2.7%

- LUCs to restrict access to Surficial Aquifer groundwater within potentially contaminated areas until Assumed

the remediation goals are timeframe: 40 years


5. Enhanced Multiple injections - Installation of a network of vertical injection wells. Capital Cost: Reductive of an organic Multiple injections of an organic substrate (serves as $2,225,000 Dechlorination substrate into energy for naturally-occurring bacteria) into (ERD), MNA and groundwater to groundwater in the areas with the highest contaminant Present Value of

LUCs enhance natural concentrations to enhance biodegradation. MNA would Future, Annual O&M

biodegradation be employed to address the remaining areas of Costs: $3,982,000 Injection of an organic processes groundwater contamination. substrate into the Total Present

groundwater to Periodic - Installation of additional monitoring wells and periodic Worth Cost:

stimulate the groundwater groundwater monitoring for COCs and natural $6,207,000

biodegradation of sampling attenuation parameters until the remediation goals are COCs. Also achieved Discount Rate: 2.7%

incorporates MNA and LUCs.

LUCs - LUCs to restrict access to Surficial Aquifer Assumed

groundwater within potentially contaminated areas until timeframe: 60 years

the remediation goals are achieved


2.8.2 Comparative Analysis of Remedial Alternatives

A comprehensive analysis of each remedial alternative with respect to the nine NCP evaluation criteria was detailed in the OU14 FS. The results of the comparative analysis and rankings of the remedial alternatives are discussed below.

Threshold Criteria Overall Protection of Human Health and the Environment. Alternative 1 (No Action) does not protect human health and the environment because potential exposure to COCs is not limited. Alternative 2 (LUCs) does not achieve RAOs because it lacks a monitoring component to determine progress toward remediation goals. Alternative 3 (MNA and LUCs), Alternative 4 (Biosparge, MNA, and LUCs), and Alternative 5 (ERD, MNA, and LUCs) are all protective of human health and the environment because potential exposure pathways to COCs in groundwater and indoor air vapors are restricted by LUCs while the

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remaining RAOs are achieved over time via MNA (Alternative 3) or a combination of active treatment and MNA (Alternatives 4 and 5).

Compliance with ARARs. There are three types of ARARs: chemical-specific, locationspecific, and action-specific. Alternative 1 does not comply with ARARs since no remedial action is taken. Alternative 2 does not comply with chemical-specific ARARs due to the lack of monitoring to assess COC concentrations and the spatial extent of contamination over time. Alternatives 3, 4, and 5 all comply with ARARs. The RI for OU14 concluded that the chlorinated VOC plumes have stabilized and that, even without treatment, no COCs will discharge in groundwater to the unnamed stream at concentrations above any applicable chemical-specific ARARs.

Since Alternatives 1 and 2 do not meet the two threshold criteria, they were subsequently eliminated from further consideration.

Primary Balancing Criteria Long-Term Effectiveness and Permanence. Alternatives 3, 4, and 5 are all expected to be effective and permanent remedies to achieve RAOs. Permanent risk reduction would be achieved by all alternatives over relatively long periods of time (estimated to range from 40 to 100 years) as COCs attenuate to concentrations below the remediation goals. Alternatives 4 and 5 both require similar LTM and O&M activities as Alternative 3, but also include technology-specific LTM and O&M. Alternative 4 requires the greatest amount of O&M activities relative to the other alternatives, because the biosparge system includes equipment and controls that require power, protection from the elements, and periodic adjustment and repair. Alternative 5 involves three substrate injection events, the maintenance of a series of injection wells, and LTM to maintain optimal conditions in the aquifer for ERD. Alternative 3 requires the least amount of long-term monitoring (LTM) and operation and maintenance (O&M) activities.

Reduction in Toxicity, Mobility, or Volume through Treatment. Alternatives 3, 4, and 5 would all effectively reduce the toxicity, mobility, and volume of COCs in groundwater through natural attenuation processes, including dispersion, diffusion, volatilization, and biodegradation. Alternatives 4 and 5 add further treatment of areas within the chlorinated VOC plumes that contain the highest concentrations of COCs in an attempt to reduce the timeframe required to achieve RAOs. Alternative 4 promotes the volatilization and biodegradation of COCs in these areas via biosparging, while Alternative 5 promotes biodegradation via ERD.

Short-Term Effectiveness. Alternatives 3, 4, and 5 all protect human health and the environment in both the short and long term. Alternative 3 is conservatively estimated to require 100 years for groundwater COC concentrations to fully reach remediation goals throughout the site; however, this estimate does not take into account the potential for petroleum contamination commingled with the chlorinated VOC plumes to facilitate the biodegradation of the COCs, nor the potential for UST Program AS/SVE systems at OU14 to reduce chlorinated VOC concentrations. The active treatments employed with Alternatives 4 and 5 in certain areas of the plumes are estimated to reduce the timeframe to achieve RAOs to 40 and 60 years, respectively.

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There are negligible risks to the community associated with the implementation of Alternatives 3, 4, and 5. All of the alternatives would require the use of standard engineering and safety controls to protect site workers during the remedial action, particularly for drilling, well installation, O&M, and LTM activities. However, Alternatives 4 and 5, each having more substantial implementation and O&M requirements, inherently have an increased potential risk to site workers.

Implementability. Alternative 3 is easily implementable, and the required services and materials are widely available. The installation of additional monitoring wells for the LTM network and the periodic sampling activities are similar between Alternatives 3, 4, and 5, but Alternatives 4 and 5 involve considerably more drilling and well installation activities.

Alternative 4 is the most technically challenging of all of the alternatives with respect to construction and O&M and has the most significant implementability challenges and concerns. The installation of horizontal biosparge wells can be performed by many environmental drillers and would minimize the substantial challenges associated with avoiding underground utilities. However, the trenching for conveyance piping, power requirements for operation, and housing and maintenance of equipment all present substantial challenges relative to Alternatives 3 and 5. There are several implementability concerns and challenges associated with Alternative 4:

This alternative poses a significantly greater potential for disruptions to flightline and other military operations relative to Alternative 3.

Subsurface air injection, even under low-flow conditions, may increase the risk of indoor air vapor intrusion issues in buildings from chlorinated VOCs as well as from petroleum contamination and free product near the areas of injection or via utility conduits to buildings near the areas of injection. If deemed necessary during system design or system startup activities, passive or active vapor mitigation systems could be installed depending on the occupancy of potentially affected buildings.

Temporary groundwater mounding may occur during and immediately after system startup, impacting groundwater flow directions and potentially disrupting existing UST Program petroleum free product extraction systems currently in place at OU14.

The technology employed in Alternative 5 is relatively easy to implement and the required services and materials are widely available. However, multiple substrate injections would be required, and the installation of the considerable number of vertical injection wells and the injection activities would create significant challenges to mitigate related to avoiding underground utilities and the potential for disruptions to flightline and other military operations. An implementability concern associated with Alternative 5 involves potential impacts from existing UST Program AS and SVE remediation systems at OU14. These systems might impede the enhancement of anaerobic conditions in portions of the site and impede ideal ERD conditions due to the injection of air (contains oxygen) into the aquifer.

Cost. Alternative 3 is the least-cost alternative, with an estimated present-worth cost of $2,076,000 associated with the installation of additional monitoring wells, conducting LTM for the MNA remedy, and for maintenance of LUCs. Alternatives 4 and 5 both include similar costs for LTM and LUCs, but for a shorter timeframe. Alternatives 4 and 5 require

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considerably higher implementation and O&M costs than Alternative 3. The estimated present-worth costs of Alternatives 4 and 5 are $5,076,000 and $6,207,000, respectively.

Modifying Criteria State Acceptance. State involvement has been continual throughout the CERCLA process for OU14 and NCDENR supports the selected remedy. The State of North Carolina concurs with the selected remedy.

Community Acceptance. The Proposed Plan was issued for public review from May 1 to June 15, 2009 and was discussed at a public meeting on May 21, 2009. The transcript from the public meeting is provided in Appendix B. Aside from questions and comments voiced and addressed at the public meeting, no other public comments on the Proposed Plan were received.

2.9 Selected Remedy

The selected remedy for OU14 groundwater is Alternative 3, MNA and LUCs. This selected remedy is the preferred alternative presented in the Proposed Plan. No further action is required for soil, sediment, or surface water.

2.9.1 Rationale for Selected Remedy

Based on the evaluation of the data and information currently available, the Navy, in partnership with EPA, believes the selected remedy meets the threshold criteria and provides the best balance of tradeoffs among the other alternatives with respect to the balancing and modifying criteria.

As described in the OU14 RI, the evaluation of natural attenuation parameters indicates that conditions are generally favorable for natural attenuation at OU14. The presence of daughter products of parent compounds indicates that natural attenuation is occurring. The low chlorinated VOC concentrations observed are amenable to natural attenuation, and the plumes appear to have stabilized. No ongoing sources have been identified at OU14.

Petroleum-related contamination is also expected to facilitate biodegradation of the chlorinated VOCs where the two plumes are commingled, and will continue to act as an energy source for naturally-occurring, dechlorinating bacteria in the aquifer. Similarly, active remediation systems for treatment of the petroleum-related contamination have a beneficial impact by reducing chlorinated VOC concentrations.

The HHRA and ERA for OU14 indicated no unacceptable risks to current receptors. The only unacceptable human health risks were to hypothetical future residents from exposure to groundwater of the surficial aquifer. Residential land use and use of surficial aquifer groundwater as a potable water source at OU14 are not likely to occur, as the site is an active flightline area on a military installation for which there is no indication of plans for closure or reassignment of mission. In addition, potable groundwater supplies at MCAS Cherry Point or in the surrounding coastal plain area of North Carolina are not derived from the surficial aquifer, but from more productive underlying aquifers that are separated from the uppermost surficial aquifer by one or more confining units that limit inter-aquifer groundwater flow.

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2 DECISION SUMMARY

Since OU14 is an active flightline area, implementation of Alternatives 4 and 5 would be disruptive to military operations. Alternative 4 would also increase the risk of indoor air vapor intrusion issues from both chlorinated VOC and petroleum contamination, and may also be temporarily disruptive to ongoing remediation efforts to recover petroleum free product. Alternative 5 is based on the enhancement of anaerobic conditions for biodegradation, which have the potential to be disrupted by existing UST Program AS/SVE remedial systems.

LUCs would be implemented at OU14 to prevent human contact with groundwater contaminated with COC concentrations above cleanup levels and minimize the potential for future vapor intrusion from COCs in groundwater underlying newly-constructed or modified buildings at OU14.

2.9.2 Description of Selected Remedy

Alternative 3, MNA and LUCs involves the implementation of a natural attenuation remedy in conjunction with groundwater performance monitoring. MNA will be performed by collecting and analyzing groundwater samples to assess that no unacceptable contaminant migration is occurring and to evaluate reductions in contaminant concentrations through naturally occurring processes such as biodegradation, dispersion, and dilution. The selected remedy will also include additional monitoring well installations and baseline groundwater sampling, performance monitoring, and Five-Year Reviews.

Performance monitoring would be implemented at OU14 to:

Demonstrate that natural attenuation is occurring

Track changes in the spatial extent(s) of the plume(s) over time as natural attenuation progresses

Verify that the downgradient extent(s) of the plume(s) is(are) not reaching the unnamed stream such that groundwater discharge to the stream would occur at concentrations above State surface water regulatory standards

Demonstrate the efficacy of institutional controls put in place to protect potential receptors

Verify attainment of remediation objectives

The objectives of the LUCs are to limit direct contact with contaminated groundwater and limit the potential for vapor intrusion from contaminated groundwater into overlying buildings. LUCs including, but not limited to, land use restrictions in the base master planning process and the filing of a Notice of Contaminated Site per North Carolina General Statutes 143B-279.9 and 143B-279.10, will be implemented to prevent exposure to contamination above remediation goals. The base master planning process will identify that no one shall use or come in contact with the surficial groundwater aquifer, except for monitoring/remediation purposes. The base master planning process will also identify the need for further evaluation of the vapor intrusion pathway if new buildings are constructed or if existing buildings are changed significantly (physical structures, occupancy, or use). LUCs will be developed during the remedial design phase following approval of the ROD for OU14. The LUCs will be implemented and maintained by the Navy and MCAS Cherry Point until the concentrations of hazardous substances in the groundwater are at levels that allow for UU/UE. The LUC boundaries for the selected remedy are shown in Figure 6.

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~W+E

S

o 250 500

~i~~~iiiiiiiiiiiiiiiiiil! Feet

~J >0.015 ~g/L, VC Lower~J >100 ~g/L, CVOCs Lower• >200 ~g/L, CVOCs Lower

24

Legendc::J LUC boundary - Intrusive activities below the

water table prohibitedNapor Intrusion evaluationrequired for building construction/modification

c::J LUC boundary - Well installation and groundwateruse prohibitedLower Surficial Aquifer Monitoring WellYorktown Aqu ifer Mon itoring Well

~ Upper Surficial Aquifer Monitoring Well- Surface Water

Upper and Lo"",r Surficial Aquifer Isoconcentralions

C>2.8 ~g/L, TCE Upper ..",11>2.8 ~g/L, TCE Lower>1 00 ~g/L, TCE Upper

o >0015 ~g/L, VC Upper0>1 00 ~g/L, CVOCs Upper• >200 ~g/L, CVOCs Upper

336 156GW0656GW12

/

2 DECISION SUMMARY

FIGURE 6

Land Use Control (LUC) Boundaries

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2 DECISION SUMMARY

The performance objectives of the LUCs include:

Prohibiting all uses of groundwater from the surficial aquifer within the LUC boundaries (except for monitoring and remediation purposes), including but not limited to, human consumption, dewatering, irrigation, heating/cooling and industrial processes, unless prior written approval is obtained from the USEPA and NCDENR

Prohibiting unauthorized intrusive activities below the water table within the LUC boundaries, unless prior written approval is obtained from the USEPA and NCDENR

Evaluating the potential for vapor intrusion impacts from new building construction or from major physical modifications or changes in occupancy/usage of existing structures within the LUC boundaries

Maintaining the integrity of any existing or future monitoring or remediation system at the site.

Although the Navy may later transfer procedural responsibilities related to the Selected Remedy to another party by contract, property agreement, or through other means, the Navy will retain ultimate responsibility for remedy integrity.

A technical memorandum will be prepared periodically to summarize the analytical results and document progress towards remediation goals.

2.9.3 Expected Outcomes of the Selected Remedy

The expected outcome of the Selected Remedy is to allow for unrestricted use of the groundwater. However, the land use at OU14 is not expected to change once the groundwater cleanup levels are met. The site is beneath and around an active runway and is expected to continue to serve this military purpose for the foreseeable future. In accordance with the objectives of the LUCs, groundwater use will be limited to monitoring or remedial purposes until the remedial goals are achieved. The MNA portion of the remedy will require assessment through LTM of groundwater quality to provide evidence that natural attenuation is occurring. When a single COC is at or below its respective remediation goal for four consecutive sampling events3, the COC will no longer require monitoring.

The time required to meet cleanup levels using the selected remedy is conservatively estimated to be 100 years. However, the estimate does not account for several factors at OU14 that may facilitate the attenuation of COCs, such as the presence of petroleum-related contamination. Baseline and performance sampling would provide temporal and geochemical data to more accurately estimate the time to achieve RAOs.

Within 90 days following signature of the ROD, the Navy will prepare, in accordance with USEPA guidance, and submit to USEPA and NCDENR for review and approval, a RD containing LUC implementation and maintenance actions, including periodic inspections. The Navy and MCAS Cherry Point are responsible for implementing, maintaining, inspecting, reporting on, and enforcing the LUCs described in this ROD in accordance with the ROD and the approved RD.

3The four consecutive sampling events will not occur more frequently than quarterly or less frequently than annually.

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2 DECISION SUMMARY

2.9.4 Statutory Determinations

In accordance with the NCP, the selected remedy meets the following statutory determinations.

Protection of Human Health and the Environment - The selected remedy is needed to restore groundwater to levels consistent with potential drinking water use and will protect human health and the environment through MNA and LUCs. Long-term groundwater monitoring will monitor the effectiveness of the natural attenuation processes in reducing the COC concentrations to achieve the remediation goals. LUCs will limit groundwater use from the surficial aquifer to monitoring and remedial purposes, prohibit unauthorized intrusive activities below the water table, evaluate the potential for vapor intrusion impacts to new buildings or the modification of existing structures, and maintain the integrity of any existing or future monitoring or remediation at the site.

Compliance with ARARs - The selected remedy will attain the Federal and State ARARs presented herein (Attachment B, Tables B-1 through B-3).

Cost-Effectiveness - The selected remedy provides the most reasonable value relative to the cost.

Utilization of Permanent Solutions and Alternative Treatment Technologies or Resource Recovery Technologies to the Maximum Extent Practicable - The selected remedy represents the maximum extent to which permanent solutions and alternative treatment technologies can be used in a practicable manner at OU14. An MNA remedy was chosen because the volumes and concentrations of COCs are low, and the remedy is expected to be successful in attaining performance standards in groundwater. MNA has been successful in meeting performance standards at other MCAS Cherry Point sites.

Preference for Treatment as a Principal Element – Although the selected remedy for groundwater does not provide for treatment as a principle element, reduction of groundwater contamination is expected over time due to natural processes. The selected remedy for groundwater represents the maximum extent to which permanent solutions and treatment are practicable at OU14, because based on the low volume and concentrations of COCs present, treatment would not be cost effective.

Five-Year Review Requirements - Because this remedy will result in hazardous substances, pollutants, or contaminants remaining on-site in groundwater above levels that allow for UU/UE, a statutory review will be conducted no less often than each 5 years after the initiation of remedial action to ensure that the remedy is protective of human health and the environment.

2.10 Documentation of Significant Changes

The Proposed Plan for OU14 was released for public comment on May 1, 2009. The Navy reviewed all comments submitted during the public comment period, which extended until June 15, 2009. It was determined that no significant changes to the remedy, as originally identified in the Proposed Plan, were necessary or appropriate.

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2 DECISION SUMMARY

2.11 Community Participation

Community participation at MCAS Cherry Point includes a Restoration Advisory Board (RAB), public meetings, a public information repository, newsletters and fact sheets, public notices, and an ERP web site. The Community Involvement Plan for MCAS Cherry Point provides detailed information on community participation for the ERP.

The RAB was formed in 1995 and consists of community members and representatives of the USEPA, NCDENR, Navy, and Marine Corps. RAB meetings are held approximately every 3 months and are open to the public to provide opportunity for public comment and input. The investigations at OU14, the findings, and potential remedial approaches have been presented and discussed at the RAB meetings. The Community Involvement Plan and technical reports supporting the remedial decision are available for download by the public via the MCAS Cherry Point ERP Public website: http://public.lantops-ir.org/sites/public/ cherrypoint/. These and other MCAS Cherry Point Administrative Record documents can be accessed by clicking on the “Admin Records” link at the top of the web site home page. If a computer and internet access is not available from home, access to the MCAS Cherry Point ERP Public web site may be obtained from the following location: Havelock-Craven County Library, 301 Cunningham Blvd., Havelock, North Carolina 28352, Phone 252-447-7509.

For additional information on the ERP, contact:

Public Affairs Office NAVFAC Atlantic 6506 Hampton Blvd. Norfolk, VA 23508-1278 757-322-8005

In accordance with Sections 113 and 117 of CERCLA, the Navy and MCAS Cherry Point provided a public comment period from May 1 through June 15, 2009, for the preferred alternative described in the Proposed Plan for OU14. A public meeting to present the Proposed Plan was held at the Havelock Tourist and Event Center, located in Havelock, North Carolina, on May 21, 2009. Public notice of the meeting and availability of documents was placed in the Sun Journal Newspaper on April 26, 2009, the Havelock News on April 29, 2009; the Windsock on April 30, 2009; and the Carteret County News-Times on April 26, 2009.

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3 RESPONSIVENESS SUMMARY

Responsiveness Summary

No written comments, concerns, or questions were received by the Navy, USEPA, or NCDENR during the public comment period. One member of the public attended the public meeting held on May 21, 2009. Navy, USEPA, and NCDENR representatives were available to present the Proposed Plan for OU14 and answer questions regarding the Proposed Plan as well as any other documents in the information repository. The transcript from the public meeting is provided in Appendix B.

3-1

4 Acronyms and References

4.1 Acronyms

ARAR applicable or relevant and appropriate regulations AS air sparge AST aboveground storage tank

bgs below ground surface BRAC Base Realignment and Closure

CAP Corrective Action Plan CERCLA Comprehensive Environmental Response, Compensation, and Liability Act CERCLIS Comprehensive Environmental Response, Compensation, and Liability

Information System COC chemical of concern CTE central tendency exposure

DCE dichloroethene

EAD Environmental Affairs Department ERA Ecological Risk Assessment ERD enhanced reductive dechlorination ERP Environmental Restoration Program

FFA Federal Facility Agreement FS Feasibility Study

GRA general response action

HHRA Human Health Risk Assessment HI hazard index HQ hazard quotient

IAS Initial Assessment Study

LUC land use control

µg/L microgram per liter MCAS Marine Corps Air Station

4-1

4 ACRONYMS AND REFERENCES

MNA monitored natural attenuation

NAS Natural Attenuation Software NAVFAC Naval Facilities Engineering Command Navy Department of the Navy NC SSL North Carolina Soil Screening Levels NCDENR North Carolina Department of Environment and Natural Resources NCGWQS North Carolina Groundwater Quality Standards NCP National Oil and Hazardous Substances Pollution Contingency Plan NPL National Priorities List

O&M Operation and Maintenance ORP oxidation-reduction potential OU operable unit

PP Proposed Plan

RAB Restoration Advisory Board RAO Remedial Action Objectives RD Remedial Design RI Remedial Investigation RME reasonable maximum exposure ROD Record of Decision

SAP Sampling and Analysis Plan SARA Superfund Amendments and Reauthorization Act SMP Site Management Plan SVE soil vapor extraction

TCE Trichloroethene TOC total organic carbon

UFP Uniform Federal Policy USEPA United States Environmental Protection Agency UST underground storage tank UU/UE unlimited use/unrestricted exposure

VOC volatile organic compound

4-2

4.2 References

Reference Number Reference Phrase in ROD

1 Federal Facility Agreement (FFA)

2 Initial Assessment Study (IAS)

3 Site Management Plan (SMP)

4 most likely former source areas

5 OU14 Remedial Investigation

6 OU14 Feasibility Study

7 petroleum contamination in soil and groundwater

8 Corrective Action Plan (CAP)

9 remedial system

10 RI for the adjacent Operable Unit 1

Location in ROD

Section 1

Section 1

Section 1

Section 2.1

Section 2.1

Section 2.1

Section 2.2, Table 1





Identification of Referenced Document Available in the Administrative Record

Naval Facilities Engineering Command (NAVFAC). 2005. Federal Facility Agreement for Marine Corps Air Station Cherry Point, North Carolina. USEPA Administrative Docket Number CERCLA-04-2005-3766.

Water and Air Research, Inc. 1983. Initial Assessment Study of Marine Corps Air Station Cherry Point, NC. Prepared for Naval Energy and Environmental Support Activity (NEESA). March.

CH2M HILL. 2009. Site Management Plan, Fiscal Year 2010, Marine Corps Air Station Cherry Point, NC. July.

CH2M HILL. 2008. Final Remedial Investigation, Operable Unit 14, Site 90, Marine Corps Air Station Cherry Point, North Carolina. December. Section 2.3 Pages 2-2 through 2-4 and Section 5.2.2 Pages 5-13 through 5-14.

CH2M HILL. 2008. Final Remedial Investigation, Operable Unit 14, Site 90, Marine Corps Air Station Cherry Point, North Carolina. December. Section 2.3 Pages 2-2 through 2-4.

CH2M HILL. 2009. Final Feasibility Study, Operable Unit 14, Site 90, Marine Corps Air Station Cherry Point, North Carolina. April. Sections 2.1 and 2.2 Pages 2-1 through 2-4.

Halliburton NUS (HNUS). 1994. Site Characterization and Evaluation Report for BRAC Sites 6 and 7 for Marine Corps Air Station, Cherry Point, NC. December.

Law Engineering. 1997. Corrective Action Plan for the Recovery of Free Product and the Restoration of Petroleum Contaminated Soil and Groundwater, Building 130, Building 3996, and Pit 4 Area, Marine Corps Air Station, Cherry Point, NC. January.

J.A. Jones Environmental Services Company (Jones). 2000. Work Plan, Task Order 045, RAC Action for Statement of Work Design, Subsurface Petroleum Remediation, Buildings 130 and 3996, Marine Corps Air Station, Cherry Point, NC. June.

TetraTech NUS (TTNUS). 2002. Final Remedial Investigation Report for OU1, Marine Corps Air Station Cherry Point, NC. November.

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11 North Carolina Groundwater Quality Standard (NCGWQS)

12 Preferred Alternative for OU14

13 hydrogeology beneath OU14

14 plumes of chlorinated VOCs

15 several natural attenuation evaluation parameters

16 constituents were not COCs

17 Predictive modeling

18 Human health risks

19 Screening-level Ecological Risk Assessment (SERA)

20 Details of the ARARs

Location in ROD



Section 2.3

Section 2.3

Section 2.3

Section 2.3

Section 2.3

Section 2.5.1

Section 2.5.2

Section 2.5.3


North Carolina Administrative Code (NCAC). Classifications of Water Quality Standards Applicable to the Groundwaters of NC. NC Administrative Code 15A NCAC 02L.0100, .0200, & .0300. http://h2o.enr.state.nc.us/admin/rules/documents /WEBversioncomp2Lw-PFOAInterim_dec06.pdf. Amended December 7, 2006.

Naval Facilities Engineering Command (NAVFAC). 2009. Proposed Plan, Operable Unit 14, Site 90, Marine Corps Air Station Cherry Point, North Carolina. April. Section 9 Pages 16 through 18.


CH2M HILL. 2008. Final Remedial Investigation, Operable Unit 14, Site 90, Marine Corps Air Station Cherry Point, North Carolina. December. Section 5.2.2 Pages 5-6 through 5-14.

CH2M HILL. 2009. Final Feasibility Study, Operable Unit 14, Site 90, Marine Corps Air Station Cherry Point, North Carolina. April. Section 2.2.4 Pages 2-13 through 2-18.

CH2M HILL. 2009. Final Feasibility Study, Operable Unit 14, Site 90, Marine Corps Air Station Cherry Point, North Carolina. April. Section 2.2.7 Page 2-23.


CH2M HILL. 2008. Final Remedial Investigation, Operable Unit 14, Site 90, Marine Corps Air Station Cherry Point, North Carolina. December. Section 7 Pages 7-1 through 7-26.

CH2M HILL. 2008. Final Remedial Investigation, Operable Unit 14, Site 90, Marine Corps Air Station Cherry Point, North Carolina. December. Section 8 Pages 8-1 through 8-13.

CH2M HILL. 2009. Final Feasibility Study, Operable Unit 14, Site 90, Marine Corps Air Station Cherry Point, North Carolina. April. Section 3.2 Pages 3-2 through 3-3 and Appendix B.

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21 preliminary screening of General Response Actions (GRAs)

22 comprehensive analysis of each remedial alternative

23 best balance of tradeoffs

Location in ROD

Section 2.8

Section 2.8.2

Section 2.9.1



CH2M HILL. 2009. Final Feasibility Study, Operable Unit 14, Site 90, Marine Corps Air Station Cherry Point, North Carolina. April. Section 4.3 Pages 4-3 through 4-4 and Tables 4-2a and 4-2b.

CH2M HILL. 2009. Final Feasibility Study, Operable Unit 14, Site 90, Marine Corps Air Station Cherry Point, North Carolina. April. Section 6 Pages 6-1 through 6-4 and Table 6-2.

Naval Facilities Engineering Command (NAVFAC). 2009. Proposed Plan, Operable Unit 14, Site 90, Marine Corps Air Station Cherry Point, North Carolina. April. Section 9 Pages 16 through 18.

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Appendix A ARARs

APPENDIX A - ARARS

TABLE A-1 Chemical-Specific ARARs Operable Unit 14, Site 90 Record of Decision Marine Corps Air Station Cherry Point, North Carolina

Action

Classification of contaminated groundwater

Restoration of contaminated groundwater

Protection of adjacent surface water body

Requirements Prerequisite

Chemical-Specific ARARs

Groundwaters in the state naturally containing 250 mg/L or less of

chloride are classified as GA under 15A NCAC 02L .0201(1)

Shall not exceed the groundwater quality standards4 for

contaminants specified in Paragraphs (g) or (h) for the site related

contaminants of concern.

Chloromethane (2.6 µg/L)

cis-1,2-Dichloroethene (70 µg/L)

1,1-Dichloroethane (70 µg/L)

1,2-Dichloroethane (0.38 µg/L)

Methylene Chloride (4.6 µg/L)

Tetrachloroethene (0.7 µg/L)

Trichloroethene (2.8 µg/L)

Vinyl Chloride (0.015 µg/L)

Shall not exceed the Safe Drinking Water Act National Revised Primary Drinking Water Regulations: maximum contaminant levels

(MCLs) for organic contaminants specified in 40 CFR 141.61(a).

Monitor and undertake management practices for sources of pollution

such that water quality standards and best usage of receiving waters

and all downstream waters will not be impaired.

Groundwaters located within the boundaries or under the extraterritorial jurisdiction of the State of North Carolina — applicable

Class GA or GSA groundwaters with contaminant(s) concentrations exceeding standards listed in 15A NCAC 02L .0202 — applicable

Groundwaters classified as GA or GSA which are an existing or potential source of drinking water— relevant and appropriate

Indirect discharges of waste or other source of water pollution into surface waters classified as Class C5 — relevant and appropriate

Citation

15A NCAC 02L .0302(1)

15A NCAC 02L .0202(a) and (b)

40 CFR 141.61(a)

15A NCAC 18C .1517

15A NCAC 02B .0203

4 Groundwater quality standards established on the basis of a National secondary drinking water standards are not utilized as remediation goals since these are based on taste, odor and other considerations unrelated to human health. 5 The unnamed stream at OU14, Sandy Branch, and East Prong Slocum Creek are classified as Class C estuarine water by NCDENR. These waters are suitable for fish and wildlife and secondary recreation (i.e., not considered suitable for swimming or potable use).

A-1

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APPENDIX A ARARS

TABLE A-1

Chemical-Specific ARARs Operable Unit 14, Site 90 Record of Decision Marine Corps Air Station Cherry Point, North Carolina

Action



Requirements Prerequisite

Chemical Specific ARARs

The concentrations of toxic substances, either alone or in combination with other wastes, in surface waters shall not render waters injurious to aquatic life or wildlife, recreational activities, public health, or impair the waters for any designated uses.

Toxic substances: shall not exceed the numerical quality standards (maximum permissible levels) to protect human health from carcinogens through consumption of fish (and shellfish).

Tetrachloroethene (3.3 µg/L)

Trichloroethene (30 µg/L)

Vinyl Chloride (2.4 µg/L)

Shall not exceed 25 NTU turbidity level (unless due to natural background conditions).

Compliance with this standard can be met when land management activities employ Best Management Practices [as defined by Rule .0202 of this Section].

Toxic substances: shall not exceed the numerical quality standards (maximum permissible levels) provided in subparagraphs (i) through (xi) to protect aquatic life.

Nonpoint discharges into surface waters classified as Class C (see footnote 2) — relevant and appropriate

Nonpoint discharges (containing toxic substances which are carcinogens) into surface waters classified as Class C (see footnote 2) — relevant and appropriate

Nonpoint discharges into surface waters classified as Class C in 15A NCAC 02B .0211 — relevant and appropriate

relevant and appropriate

Citation

15A NCAC 02B .0208

15A NCAC 02B .0208(a)(2)B)

15A NCAC 02B .0211(3)(k)

15A NCAC 02B .0211(3)(l)

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APPENDIX A ARARS

TABLE A-2

Location-Specific ARARs Operable Unit 14, Site 90 Record of Decision Marine Corps Air Station Cherry Point, North Carolina

Action Requirements Prerequisite Citation

Location Specific ARARs

Presence of floodplain Shall consider alternatives to avoid, to the extent possible Federal actions that involve potential Executive Order designated as such on a adverse effects and incompatible development in the impacts to, or take place within, 11988 Section 2(a)(2) map floodplain. floodplains—TBC

A-3

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APPENDIX A ARARS

TABLE A-3

Action-Specific ARARs Operable Unit 14, Site 90 Record of Decision Marine Corps Air Station Cherry Point, North Carolina

Action

Managing fugitive dust emissions

Construction of groundwater monitoring well(s)

Implementation of groundwater monitoring system

Requirements Prerequisite Citation

General Construction Standards All Land disturbing Activities (i.e., excavation, clearing, grading, etc.)

Shall not cause or allow fugitive dust emissions to cause or contribute to substantive complaints, or visible emissions in excess of that allowed under paragraph (e) of this Rule.

Activities within facility boundary that will generate fugitive dust emissions — relevant and appropriate

15A NCAC 02D .0540(c)

Implement methods (e.g. wetting dry soils) to control dust emissions that could travel beyond the facility boundary.

relevant and appropriate 15A NCAC 02D .0540(g)

Monitoring Well Installation, Operation, and Abandonment

No well shall be located, constructed, operated, or repaired in any manner that may adversely impact the quality of groundwater.

Installation of wells (including temporary) other than for water supply — applicable

15A NCAC 02C .0108(a)

Shall be located, designed, constructed, operated and abandoned with materials and by methods which are compatible with the chemical and physical properties of the contaminants involved, specific site conditions, and specific subsurface conditions.

applicable 15A NCAC 02C .0108(c)

Must comply with general requirements for construction of a well as provided in 15A NCAC 02C .0108(c)(1) through (12)


Shall be constructed in such a manner as to preclude the vertical migration of contaminants with and along borehole channel.

applicable 15A NCAC 02C .0108(f)

Shall be constructed in a manner that will not result in contamination of adjacent groundwaters of a higher quality.

Installation of monitoring system to evaluate effects of any actions taken to restore groundwater quality, as well as the efficacy of treatment — applicable

15A NCAC 02L .0110 (b)

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APPENDIX A ARARS

TABLE A-3


Action

Maintenance of groundwater monitoring well(s)

Abandonment of groundwater monitoring well(s)

Characterization of solid waste (e.g., well soil cuttings)

Requirements

Every well shall be maintained by the owner in a condition whereby it will conserve and protect groundwater resources, and whereby it will not be a source or channel of contamination or pollution to the water supply or any aquifer.

Broken, punctured, or otherwise defective or unserviceable casing, screens, fixtures, seals, or any part of the well head shall be repaired or replaced, or the well shall be abandoned pursuant to 15A NCAC 02C .0113

All materials used in the maintenance, replacement, or repair of any well shall meet the requirements for new installation.

Shall be abandoned in accordance with the requirements of 15A NCAC 02C .0113(b)(1) and (2)

Prerequisite Citation

Installation of wells (including temporary wells) 15A NCAC 02C other than for water supply — applicable .0112(a)


applicable 15A NCAC 02C .0112(b)

Permanent abandonment of wells (including 15A NCAC 02C temporary wells) other than for water supply — .0113(b) applicable

Waste Characterization and Storage Primary Wastes (i.e., excavated contaminated soils)

Must determine if solid waste is hazardous waste or if waste is excluded under 40 CFR 261.4(b); and

Must determine if waste is listed under 40 CFR Part 261; or

Must characterize waste by using prescribed testing methods or applying generator knowledge based on information regarding material or processes used.

Must refer to Parts 261, 262, 264, 265, 266, 268, and 273 of Chapter 40 for possible exclusions or restrictions pertaining to management of the specific waste.

Generation of solid waste as defined in 40 CFR 261.2 and which is not excluded under 40 CFR 261.4(a) —applicable

applicable

40 CFR 262.11(a)

40 CFR 262.11(b)

applicable 40 CFR 262.11(c)

Generation of solid waste which is determined to be hazardous —applicable

40 CFR 262.11(d)

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APPENDIX A ARARS

TABLE A-3


Action Requirements

Storage of solid waste All solid waste shall be stored in such a manner as to prevent the creation of a nuisance, insanitary conditions, or a potential public health hazard.

Containers for the storage of solid waste shall be maintained in such a manner as to prevent the creation of a nuisance or insanitary conditions.

Containers that are broken or that otherwise fail to meet this Rule shall be replaced with acceptable containers.

Characterization of hazardous waste

Must obtain a detailed chemical and physical analysis on a representative sample of the waste(s), which at a minimum contains all the information that must be known to treat, store, or dispose of the waste in accordance with pertinent sections of 40 CFR 264 and 268.

Must determine the underlying hazardous constituents [as defined in 40 CFR 268.2(i)] in the waste.

Must determine if the waste is restricted from land disposal under 40 CFR 268 et seq. by testing in accordance with prescribed methods or use of generator knowledge of waste.

Must determine each EPA Hazardous Waste Number (Waste Code) to determine the applicable treatment standards under 40 CFR 268.40 et. seq.


Generation of solid waste which is determined not 15A NCAC 13B to be hazardous —relevant and appropriate .0104(f)

relevant and appropriate 15A NCAC 13B .0104(e)

Generation of RCRA-hazardous waste for 40 CFR storage, treatment or disposal —applicable 264.13(a)(1)

Generation of RCRA characteristic hazardous 40 CFR 268.9(a) waste (and is not D001 non-wastewaters treated by CMBST, RORGS, or POLYM of Section 268.42 Table 1) for storage, treatment or disposal — applicable

applicable 40 CFR 268.7

applicable 40 CFR 268.9(a)

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TABLE A-3


Action

Temporary storage of hazardous waste in containers

Use and management of hazardous waste in containers

Disposal of solid waste

Requirements

A generator may accumulate hazardous waste at the facility provided that:

waste is placed in containers that comply with 40 CFR 265.171-173; and

the date upon which accumulation begins is clearly marked and visible for inspection on each container

container is marked with the words ―hazardous waste‖; or

container may be marked with other words that identify the contents.

If container is not in good condition (e.g. severe rusting, structural defects) or if it begins to leak, must transfer waste into container in good condition

Use container made or lined with materials compatible with waste to be stored so that the ability of the container is not impaired

Keep containers closed during storage, except to add/remove waste

Open, handle and store containers in a manner that will not cause containers to rupture or leak

APPENDIX A ARARS


Accumulation of RCRA hazardous waste on site 40 CFR 262.34(a) as defined in 40 CFR 260.10 — applicable

40 CFR 262.34(a)(1)(i)

applicable 40 CFR 262.34(a)(2)

applicable 40 CFR 264.34(a)(3)

Accumulation of 55 gal. or less of RCRA 40 CFR hazardous waste at or near any point of 262.34(c)(1) generation — applicable

Storage of RCRA hazardous waste in containers 40 CFR 265.171 — applicable

applicable 40 CFR 265.172

applicable 40 CFR 265.173(a)

applicable 40 CFR 265.173(b)

Waste treatment and disposal primary wastes (excavated contaminated soils)

Shall ensure that waste is disposed of at a site or facility Generation of solid waste intended for off-site 15A NCAC 13B which is permitted to receive the waste. disposal — relevant and appropriate .0106(b)

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APPENDIX A ARARS

TABLE A-3


Action

Disposal of RCRAhazardous waste in a landbased unit

Transportation of hazardous waste on-site

Transportation of hazardous waste off-site

Citation

40 CFR 268.40(a)

40 CFR 268.49(b)

40 CFR 262.20(f)

40 CFR 262.10(h)

40 CFR 263.10(a)

Requirements

May be land disposed if it meets the requirements in the table ―Treatment Standards for Hazardous Waste‖ at 40 CFR 268.40 before land disposal.

Must be treated according to the alternative treatment standards of 40 CFR 268.49(c) or

Must be treated according to the UTSs [specified in 40 CFR 268.48 Table UTS] applicable to the listed and/or characteristic waste contaminating the soil prior to land disposal.

Transportation of Wastes

Prerequisite

Land disposal, as defined in 40 CFR 268.2, of restricted RCRA waste —applicable

Land disposal, as defined in 40 CFR 268.2, of restricted hazardous soils —applicable

The generator manifesting requirements of 40 CFR

262.20 262.32(b) do not apply. Generator or transporter must comply with the requirements set forth in 40 CFR 263.30 and 263.31 in the event of a discharge of hazardous waste on a private or public right-of-way.

Must comply with the generator requirements of

40 CFR 262.20 23 for manifesting, Sect. 262.30 for packaging, Sect. 262.31 for labeling, Sect. 262.32 for marking, Sect. 262.33 for placarding, Sect. 262.40, 262.41(a) for record keeping requirements, and Sect. 262.12 to obtain EPA ID number.

Must comply with the requirements of 40 CFR

263.11 263.31.

A transporter who meets all applicable requirements of

49 CFR 171 179 and the requirements of 40 CFR 263.11 and 263.31 will be deemed in compliance with 40 CFR 263.

Transportation of hazardous wastes on a public or private right-of-way within or along the border of contiguous property under the control of the same person, even if such contiguous property is divided by a public or private right-of-way — applicable

Off-site transportation of RCRA-hazardous waste — applicable

Transportation of hazardous waste within the United States requiring a manifest — applicable

applicable

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TABLE A-3


Action Requirements

Transportation of Shall be subject to and must comply with all applicable hazardous materials provisions of the HMTA and DOT HMR at 49 CFR 171

180.

APPENDIX A ARARS


Any person who, under contract with a department or agency of the federal government, transports ―in commerce,‖ or causes to be transported or shipped, a hazardous material — applicable

49 CFR 171.1(c)

Institutional Controls for Contamination Left in Place

Notice of Contaminated Prepare and certify by professional land surveyor a survey Site plat which identifies contaminated areas which shall be

entitled ―NOTICE OF CONTAMINATED SITE‖.

Notice shall include a legal description of the site that would be sufficient as a description in an instrument of conveyance and meet the requirements of NCGS 47-30 for maps and plans.

The Survey plat shall identify:

• the location and dimensions of any disposal areas and areas of potential environmental concern with respect to permanently surveyed benchmarks;

• the type location, and quantity of contamination known to exist on the site; and

•any use restriction on the current or future use of the site.

Notice (survey plat) shall be filed in the register of deeds office in the county which the site is located in the grantor index under the name of the owner.

The deed or other instrument of transfer shall contain in the description section, in no smaller type than used in the body of the deed or instrument, a statement that the property is a contaminated site and reference by book and page to the recordation of the Notice.

Contaminated site subject to current or future use NCGS 143Brestrictions included in a remedial action plan as 279.10(a) provided in G.S. 143B-279.9(a) — TBC

TBC NCGS 143B279.10(a)(1)-(3)

TBC NCGS 143B279.10(b) and (c)

Contaminated site subject to current or future use NCGS 143Brestrictions as provided in G.S. 143B-279.9(a) 279.10(e) that is to sold, leased, conveyed or transferred — TBC

A-9

Appendix B PRAP Meeting Transcript

1 PUBLIC MEETING

2 PROPOSED REMEDIAL ACTION PLAN (PRAP)

3 OPERABLE UNIT 14, SITE 90

4 MARINE CORPS AIR STATION, CHERRY POINT, NORTH CAROLINA

5 MAY 21, 2009

6 HAVELOCK TOURIST AND EVENT CENTER 201 TOURIST CENTER DRIVE

7 HAVELOCK, NORTH CAROLINA 28532

8 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *

9 MEETING MODERATOR - MR. JEFF CHRISTOPHER

10 INSTALLATION RESTORATION PROGRAM

11 ENVIRONMENTAL AFFAIRS DEPARTMENT

12 MARINE CORPS AIR STATION

13 CHERRY POINT, NORTH CAROLINA 28533

14 PRESENTER - MR. DOUGLAS BITTERMAN

15 SENIOR PROJECT MANAGER/HYDROGEOLOGIST,

16 CH2M HILL

17 5700 CLEVELAND STREET, SUITE 101

18 VIRGINIA BEACH, VIRGINIA 23462

19 REPORTER LINDA W. LITTLE

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1 LIST OF ATTACHMENTS

2 ATTACHMENT [1] PROPOSED PLAN FOR OPERABLE UNIT 14 (OU14),

3 SITE 90, MCAS CHERRY POINT, NORTH CAROLINA

4 ATTACHMENT [2] MAP OF OPERABLE UNIT 14 (OU14), SITE 90

5 MCAS CHERRY POINT, NORTH CAROLINA

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REPORTER'S NOTE: The public meeting convened at

6:15 P.M., at the Havelock Tourist and Event Center,

Havelock, North Carolina.

MR. JEFF CHRISTOPHER: Thank ya'll for coming to

attend the meeting on the Operable Unit 14 Proposed Remedial

Action Plan for Cherry Point. My name is Jeff Christopher; I

work with environmental affairs on base. I would like to

introduce everybody. George Lane with North Carolina Department

of Environment and Natural Resources, the State Regulator.

Ms. Gena Townsend with the Environmental Protection Agency.

Dale McFarland with the Marine Corps Air Station, Cherry Point.

Jan Nielsen with the Naval Facilities Command. Patricia

McClellan-Green with The Restoration Advisory Board. Doug

Bitterman with the CH2M Hill, and he will be your speaker this

evening. Erica DeLattre, is that correct?

MS. ERICA DELATTRE: Yes.

MR. JEFF CHRISTOPHER: -- with RHEA, and Tim Wenk

and Bill Hannah with CH2M Hill, here also. I ask that as we

are presenting, if you have questions, please state your name

for the Court Reporter -- for the stenographer, and we will

try to answer it as it is asked. Doug, take it away.

MR. DOUG BITTERMAN: My name is Doug Bitterman. I'm

with CH2M Hill; I'm a hydrogeologist and project manager. CH2M

Hill is the Navy Contractor that has done most of the

investigation work at Operable Unit 14, and my job here this

evening is to present the proposed plan for Operable Unit 14 to

you, which Pat, you received your's in the mail. Basically,

tonight I'm going to go through the information that's

presented in the plan. In doing that, I will cover background

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information on Operable Unit 14. I will talk about the

investigation results from the various sampling that we did at

OU14. I'll talk about the evaluation of remedial alternatives

that we went through to provide information for the team to

come up with the preferred remedy that's in the proposed plan.

And I will talk about that preferred remedy and the rationale

for why the team came to the conclusion that it was the best

alternative. And the main reason we're all here is to solicit

public comments on the proposed plan. We are in the middle of

the 45-day public comment period; it started on May 1 and

extends to June 15. And any comments that you have can be

verbally expressed this evening, or later in writing up until

June 15. The main format for today is informal. You do not need

to wait until the end of the meeting to ask questions. Simply

raise your hand when and if you have a question. As Jeff

already said, please state your name before speaking so that

the stenographer can accurately record your name. And we did a

little sound check before the meeting; it should be okay for

you to be heard -- Pat and people on this side of the room, but

try to project so that she can catch your question accurately.

And if at any time, if I fail to define a term, or I'm going

too fast or too slow, just give me a hint, and I'll try to

speedup.

So, before getting into Operable Unit 14, I just

wanted to remind everyone about the regulation that governs all

the work that the team has done. And that is CERCLA,

Comprehensive Environmental Response Compensation and Liability

Act, or commonly known as Superfund. And this graphic shows the

various steps in that process that we have been following. The

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earliest step is the preliminary Assessment/Site Investigation

Phase. And that's basically when you are determining whether or

not there is even a problem at a site that you suspect there

might be one. The Preliminary Assessment or PA is more of a

paper study looking at historical documents, whether or not

there was a release. The site investigation is when you take

very limited samples just to confirm whether or not there's an

environmental issue. Assuming that you do find something that

needs further investigation, you move on to the Remedial

Investigation or RI Phase. That's a much more comprehensive

sampling, an investigation effort to delineate the nature and

extent of contamination. You also quantify human health and

ecological risks that may be present at that stage. We

completed -- we started on our remedial investigation of

Operable Unit 14 in around 2001. And we ended up having to do

several phases of investigation, because we kept finding that

the contamination had extended further than we thought. So the

final remedial investigation report was finalized in December

of 2008. The next phase after that, assuming that you do find

human health and ecological risk, is to do a Feasibility Study,

an FS, and that is when you come up with a list of remedial

alternatives to address those risks, and do a technical

evaluation to give the team information about which alternative

might be the more feasible or better alternative. We just

completed our Feasibility Study in Operable Unit 14, finalized

in April of 2009.

That brings us to the next step, where we are tonight,

which is the proposed plan or the Proposed Remedial Action

Plan, sometimes called a PRAP. That's when the preferred

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alternative that the team selected based on the Feasibility

Study is presented to the public and an opportunity is provided

for comments on that plan. The stuff we'll be going to next

after public comment period is over, is the record of decision

or ROD; that is when the selected remedy is formally documented

in a decision document. The transcript from this evening's

public meeting will be incorporated in the ROD and any comments

received will be taken into consideration and might possibly

result in changes to the remedy. And after the ROD, we

basically get to implementing the remedial action, the design

and the construction of the remedy.

Now, there's one thing that's not shown on here that I

wanted to make sure I pointed out. When the remedy is

constructed, that's not the end of the process. There is a

five-year review process in CERCLA that, until the remedy is

actually finished, every five years we need to evaluate whether

the remedy is still working, whether there are any problems,

whether it's still protecting human health and the environment.

So, until the remedy is actually complete, there's an on going

process to make sure that the remedy is still working properly.

I mentioned that we've completed the Remedial Investigation and

Feasibility Study Reports in the last six months. I have copies

of them here, if you want to peruse them, but they provide a

lot more detail than I'll be getting into tonight. These

documents are part of the administrative record for Cherry

Point which is available online at this web address. When you

go in there, there's an "Admin Records" link that you can click

on and that takes you to the complete administrative record

including these two documents which are the major background

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documents for OU14. If you don't have access to the internet

from home, at the Havelock Public Library there's a computer

that's provided by the Navy that is prioritized for access to

the administrative record. If you ask at the reference desk for

access to that, they'll help you get online and access the

"Admin Records" from Cherry Point.

These topics are the major parts of the proposed plan

and I'll basically be walking through them in the order shown

there. I will not be reading you a glossary of terms, but if I

ever fail to define one, just let me know if you have any

questions about any terms, just stop me.

So, getting to the background in Operable Unit 14, this

is a map of Cherry Point. And Operable Unit 14 came to be in

the year 2000, when this building here, it's a large aircraft

hangar, building 130. In the vicinity of that building,

groundwater contamination was discovered containing chlorinated

volatile organic compounds. And volatile organic compounds are

chemicals that tend to evaporate or volatilize into air.

Chlorinated VOCs or volatile organic compounds contain

chlorine, one or more chlorine atoms in the molecule.

Chlorinated VOCs make good solvents, and that's why they're

commonly found in the ground around industrial facilities like

Cherry Point, where degreasing and metal parts cleaning and

things are common occurrences. So, it's not a surprise that we

have chlorinated VOCs. So, the red box was the original

Operable Unit 14 or Site 90 -- the vicinity of hangar 130. As

we began to investigate, we quickly realized that the

chlorinated VOC contamination extended outside of this red box.

And by the time we were finished, our study area included most

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of what's inside that green box. Now this area in Operable Unit

14 is basically the flight line complex for the air station.

It's almost entirely paved; there are parking areas for

aircraft. One of the major runways here -- lots of hangars and

buildings. And I believe I have a picture on the next slide

here that gives you a great idea of what Operable Unit 14 looks

like. This is looking to the northwest, parallel to the runway.

The runway is just out of sight to the right here. This is

building 130, the large aircraft hangar I mentioned. And as you

can see, it's almost entirely covered with pavement or

concrete. This is the taxiway and parking area for aircraft at

the air station. Here's an aerial photo zooming in to Operable

Unit 14. And I'm not going to talk about every one of these

features, but as we go through the presentation, we've got two

blow-ups here that we can refer to. But just a few things that

I wanted to point out; here's hangar 130 again, you'll hear a

lot about wash racks, because one of the major sources of

contamination appears to be wash racks. There's one outside of

hangar 130 and a couple more down the runway complex. This is

Tank Farm A, which is one of several fuel storage areas for the

air station. And Tank Farm A feeds into an underground fueling

pipeline system for aircraft out here. And, as you'll see,

there's also petroleum contamination at Operable Unit 14. The

other thing I wanted to point out right now is this unnamed

stream. Almost the whole area is paved; it's not until you get

down here that you get any grass or anything that you could

remotely call a habitat. And basically this unnamed stream is

the habitat at Operable Unit 14. It is -- it basically receives

storm water drainage from this whole area, and actually, the

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1 drainage ditch, I believe, starts up here and there is a

2 culvert under this taxiway and it continues. Down in this area,

3 the stream is actually deep enough that it intersects the water

4 table, and shallow groundwater discharges into it. And it also

receives a lot of storm water. It flows this way, starting here

6 it's a culvert, goes underneath the runway and joins Mill Creek

7 here. And that continues to flow to the northwest down to East

8 Prong Slocum Creek. Is that correct Jeff?

9 MR. CHRISTOPHER: Yes. You also need to

mention -- I'll mention it. All the way down, it's all

11 concrete. It's a cement culvert.

12 MR. BITTERMAN: Up here?

13 MR. CHRISTOPHER: Yeah, all that is cemented,

14 concrete culvert.

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stream.

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MR. BITTERMAN: Okay. Yeah, it's not just --

MR. CHRISTOPHER: Until you get up to where you see

MS. PAT McCLELLAN-GREEN: Yeah.

MR. CHRISTOPHER: Then it's the actual natural

MR. BITTERMAN: The other thing I did want to

22 mention, too, is that there are a couple of petroleum

23 remediation systems in place within Operable Unit 14 addressing

24 that contamination, which I'll talk more about later. This

pinkish box is the extent of one of those systems, an air

26 sparge – injecting air into the groundwater system. So, if we

27 can refer back to this later.

28 But moving along, there are no historical documents

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1 that we have that say anything about disposal of contamination

2 or spills, or releases of contamination. So, basically, we've

3 had to infer to where the contaminates likely were released.

4 Obviously, there were releases because we had contamination in

groundwater. But since we don't have any records of where they

6 may have originated, we've had to delineate the extent of any

7 contamination and then infer where they likely came from by

8 looking at the highest concentration areas, and seeing what

9 parts of Operable Unit 14 are near those areas. Basically,

we've come up with these four apparent source areas from doing

11 that kind of analysis. The first one is the building 130 wash

12 rack. This is hangar 130, building 130. The wash rack is this

13 area right in here -- a place where aircraft are parked and

14 then washed. Solvents must have been used at some time in that

process and may have leaked into the ground either through

16 cracks in the pavement -- there are drains to the industrial

17 sewer system. Perhaps they were leaky, those drains or the

18 sewer system itself leaked. Nevertheless, there does appear to

19 be contamination that originated from this wash rack area.

MS. McCLELLAN-GREEN: Is that wash rack still in

21 use?

22 MR. BITTERMAN: It is. I don't know -- has it been

23 improved or changed at all, historically?

24 MR. DALE McFARLAND: Well, they don't wash with

solvents at all.

26 MS. McCLELLAN-GREEN: But they still wash.

27 MR. McFARLAND: Yes, they still wash.

28 MS. McCLELLAN-GREEN: Is that wash rack still

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used?

MR. CHRISTOPHER: Yes.

MR. BITTERMAN: I believe they all are, or the two

that are listed here are still in use.

MR. CHRISTOPHER: All of them are.

MR. BITTERMAN: The second one is the C-130 wash

rack. That's right here. Here's building 130. This is a wash

rack for the large C130 aircraft. That appears to be a source

area. The area around building 4075, which is this guy right

here, if I'm not mistaken, there are several possible sources

around building 4075. There's a former waste solvent

underground storage tank, another wash rack and then a

hazardous waste above-ground storage tank. Anyone or all of

those may have contributed, but there's clearly contamination

that originated from that area. And then finally a former

refueling station up in this area appears to be a minor source

of contamination. We don't have any understanding of exactly

how that occurred – why solvents from the groundwater are

running to the refueling station, but nevertheless, you'll see

there is some contamination.

MS. McCLELLAN-GREEN: Would that be from their

fuel pits -- heavy fuel pits?

MR. BITTERMAN: Um --

MR. CHRISTOPHER: No.

MR. BITTERMAN: -- these guys?

MS. McCLELLAN-GREEN: Yeah.

MR. BITTERMAN: Well, the plumes extend into

that area, but they appear to more originate from this

building 4075 area. But they do extend under that, and

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there's petroleum contamination in that area.

This slide is a conceptual site model of the

Hydrogeology of Operable Unit 14. You can see the aerial photo;

here's building 130 to the southwest, heading to the northeast;

here's that unnamed stream. The horizontal features are to

scale. There is a great deal of vertical exaggeration in this

figure. So, keep that in mind. It's thousands of feet across

here. This is only -- what's shown here is about 150 feet of

vertical thickness. So, beneath Operable Unit 14 and beneath

all Cherry Point are a series of sandy water-bearing units,

which we call aquifers. We show the top two of them in this

figure. This Surficial Aquifer, which is the uppermost, which

features the water table. And then the Yorktown Aquifer is the

next one down. We only show these two, because our

investigation activities at Operable Unit 14 did not extend

beyond that. In fact, all of the contamination in groundwater

was found to be contained in the Surficial Aquifer.

MS. McCLELLAN-GREEN: That's like the darker

green and the light green?

MR. BITTERMAN: It's, yeah, the contamination -

-it's kind of hard to see in the graphic; it may be better on

the printout, but the darker green is meant to be a general

conception of the contamination.

MS. McCLELLAN-GREEN: Okay.

MR. BITTERMAN: Separating the aquifers are clay,

mostly clay units that are not very permeable. So, ground water

can move very slowly across them, but they do restrict flow

based on the low permeability. What I want to say about this

Surficial Aquifer is, as you can barely see on here, that the

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groundwater contamination is not equally distributed vertically

across the aquifer in all different places. Here it's more

towards the bottom of the aquifer. Here it's more to the top.

So, in order to be more precise in describing where

contamination is vertically, we have --we often refer to the

upper Surficial Aquifer and the lower Surficial Aquifer. So,

actually, it's all one aquifer; there's no physical separation;

it's just for convenience in describing more precisely what

we're talking about. The aquifer is about 50 feet thick. When

we say the upper, we're talking about the top 25 feet or so --

the bottom 25feet when we're talking about the lower. And,

usually, we have wells screened, in one or the other or both at

a particular location to get that vertical delineation. Another

important point, the water supply for Cherry Point is derived

from groundwater, but not from these upper aquifers. There are

several more aquifers below these. Below the Yorktown, there's

another confining unit, and then the Pungo River Aquifer. Below

that, another confining unit and the Castle Hayne Aquifer. The

Castle Hayne, which is generally 200 feet or more in depth at

Cherry Point, is the primary drinking water -- potable water

aquifer at the air station. There are no water supply wells in

the vicinity of Operable Unit 14. So, there's a great deal of

horizontal and vertical separation in between this

contamination and any potable water supplies. So, Operable Unit

14 does not pose any threat to potable water supplies at Cherry

Point.

So, moving into the Remedial Investigation findings, we

looked at all the media out there. With respect to soil, we

ultimately did not find any chlorinated VOCs in the soil

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samples that we collected. And keep in mind there's really not

any exposed soil around the source area. So, we had to core

through concrete or asphalt to get to the soil. But in all

those source areas that I identified, we did collect soil

samples attempting to find residual chlorinated VOC

contamination and we ultimately did not find any. That's

important because if there was substantial amounts of that

contamination, it could be an ongoing source of groundwater

contamination in the future. But we did not find any, so, it

does not appear that -- it's possible we missed some small

isolated areas, but there does not appear to be any significant

remaining soil contamination with chlorinated VOCs. Groundwater

is where most of the action is at OU14. We find these

chlorinated VOCs in various plumes, which are the elongated

areas where the contamination has migrated with groundwater

flow. And basically, those plumes can be described as

containing trichloroethene, or TCE, is the primary chlorinated

volatile organic compound. TCE is probably the most common

solvent that was used historically for degreasing and parts

cleaning. And what we see is plumes of TCE that have undergone

many years of biodegradation and natural attenuation. And such

that the amount of biodegradation leads us to believe that the

releases likely occurred 30 to 60 years ago, quite a longtime

ago. I'll have more about biodegradation as we go along, but as

TCE biodegrades, it transforms into other chlorinated VOCs. And

we call those "daughter products" because they originate from

the parent TCE. The most common ones we find at OU14 are 1,2-

Dichloroethene, or l,2-DCE, and vinyl chloride. We find them

quite frequently in OU14. As I said before, the contamination

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was found to be limited to the Surficial Aquifer. We drilled

wells down into the Yorktown and did not find any chlorinated

VOCs. So, that confining unit has prevented the contamination

from reaching that lower aquifer. A little bit more about

biodegradation. The TCE is actually biodegraded by naturally

occurring bacteria that is found in the aquifer. The process is

called reductive dechlorination, and this process occurs

naturally under anaerobic conditions, which means the absence

of oxygen. And basically, I guess, the simplest way to describe

it -- it's not precisely accurate, but is to say that the

contamination is food for the bacteria. And as the bacteria

metabolize the contamination, chlorine atoms on the molecule

are replaced with hydrogen that are produced by the bacteria.

So this chart shows TCE, the parent compound, trichloroethene

refers to the three chlorine atoms on the molecule. And as it

biodegrades, the first step is for one of those chlorines to be

replaced with a hydrogen atom. You end up with 1,2-

dichloroethene, di meaning two chlorines. Then as the

biodegradation proceeds further, another chlorine atom is

replaced with a hydrogen and you end up with vinyl chloride,

which has one chlorine. Proceeding further on, the last

chlorine atom replaced with hydrogen, you end up with ethene,

which is a completely harmless compound. The chlorine makes all

the difference with respect to toxicity. So, once they're gone,

you have harmless product. So, this is the biodegradation

process that is occurring. Now, I have a couple of slides here,

which I beg your patience as we go through them. There's quite

a bit of information packed into them. This is meant to get to

the distribution of contamination and the magnitude of

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contamination. So, the figure is kind of hard to see on the

screen, but you have an oversized copy of it there that you can

look at if you're having trouble seeing it. But, basically,

when we look at the contamination in Operable Unit 14, we see,

in a nut shell, relatively low TCE concentrations and then the

widespread presence of these TCE daughter products. And this

table basically summarizes the most common chlorinated VOCs

that we find at Operable Unit14; the TCE and then the two

daughter products 1,2-DCE and vinyl chloride. Now, this table

shows both the State and the Federal Regulatory Groundwater

Standards for those compounds. This is the North Carolina

Groundwater Quality Standard, and this is the Federal Maximum

Contaminate Level, or MCL, that's a Federal drinking water

standard. And then the last column shows what we found at OU14,

the maximum concentration in micrograms per liter, which is

equivalent to parts per billion. One part TCE per billion parts

of water. The maximum concentration that we found at OU14 is

180 micrograms per liter. And I say that's relatively low by

comparison at Operable Unit l, the industrial part of the air

station. Underneath building 130, we found TCE above50,000, in

quite a number of places. But the most we have is 180 at

Operable Unit 14. The highest concentration of1,2-DCE was also

180. And then the highest concentration of vinyl chloride was

48.

So getting to the spacial distribution, and this

figure's meant to show everything in one figure. So, bear with

me as I talk you through it. You can basically see graphically

the distribution of contamination. The blue arrows show

groundwater flow direction; the purple is TCE. But, basically,

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the way this figure works is that the solid lines show where

contamination is in the upper part of the aquifer. The dashed

lines show in the lower part of the aquifer. So, the purple is

TCE, the shaded TCE is where TCE is found above 100 micrograms

per liter. And only this little, or relatively little patch

right here, is where we found TCE above 100.

MS. McCLELLAN-GREEN: But you said you found it in

excess of 50,000 under 130.

MR. BITTERMAN: No, I'm sorry. Building 133 at

Operable Unit 1, which is off the chart.

MS. McCLELLAN GREEN: Okay.

MR. BITTERMAN: Yeah, and that's at a different

Operable Unit. I was trying to show how relatively little

concentrations at Operable Unit 14 --


MR. BITTERMAN: -- higher concentrations at

Operable Unit 1.

MS. McCLELLAN-GREEN: I missed the building

number then.

MR. BITTERMAN: Yeah. Yeah, if I meant -- if I said

130, that was a mistake it's 133. That's one of the fleet

readiness center east --

MS. McCLELLAN-GREEN: Helping it out, right.

MR. BITTERMAN: Okay. The solid line not shaded is

the extent of TCE in the upper surficial above the2L that North

Carolina Groundwater Quality Standards of 2.8.So, that is this

area here, this area here, and this little area here. And the

dashed lines show where TCE is above 2.8 in the lower part of

the aquifer. Which is, let's see, starting down here in this

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area here, this area here, and this area here, and this little

area there. So, that's TCE, the parent compound. We're not so

much interested in the distribution of DCE because the standard

is higher, so we put vinyl chloride on because the North

Carolina Standard is a very low .015 micrograms per liter. And

the yellow shows the distribution of that. The solid lines are

where it's above that 0.015 in the upper part of the aquifer.

That's here, here -- those are the two areas. And in the lower

part of the aquifer, it's a little bit hard to see, but right

here, and then right here. Then to capture all the remaining

chlorinateds, we've used the green shading; that's to show

total chlorinated volatile organics. Basically, at a sample

location, we sum the total of all the concentrations of

chlorinateds up. And we just show the levels above 100

micrograms per liter on this figure. And it's the green

shading. The lighter green is above 100.The darker green is

above 200. So, in the upper part of the aquifer that's this

area here, in the lower part of the aquifer, these areas here.

I wanted, before I go on – if you were to take a knife and

slice through the earth along the long axis of the plume, and

look at it from the side, you would see something like this.

And again, it's hard to see on the screen, you have a -- if you

flip over that oversized figure, you'll find this figure on

your handout. The color scheme is the same, the purple reddish

is the TCE. This shows where TCE is above the groundwater

standards 2.8, and you can see that. This is hangar 130 here;

this is the unnamed stream here. Ground-water flow is from

right to left. So, you can see in these areas we have TCE

contamination. The yellow shows where vinyl chloride is above

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the standard in this area here, and this area here. And I only

show the total chlorinated VOCs above 200 on here, because all

of these purple and yellow would be covered by the area greater

than 100. So, just so you can see it, I limited it to over 200

micrograms per liter.

I mentioned before that there is petroleum

contamination in Operable Unit 14. And there is quite a bit of

it, including free product, which means actual petroleum fuel

that you can hold in your hand, can be found across OU14. The

underground storage tank program is responsible for the

investigation and the remediation of the petroleum. So, our

team is not engaged in trying to clean that up. But we are

interested in the presence of this contamination, and I'll

explain more about that later. But we found petroleum in soil

across a lot of OU14 above standards -- in the Surficial

Aquifer including free product. And again, the UST program is

handling that. Why we're interested in it is that, ironically,

the presence of this petroleum co-mingled with our chlorinated,

actually helps us. I don't think it helps them, but the

petroleum contamination actually can act as an energy source

and enhance that biodegradation. So, that's why we're

interested in delineating it, and understanding where there is

that petroleum contamination, because it can actually help the

biodegradation of our contamination. And this is a figure

showing one particular petroleum compound, benzene. And the

detail's not important, but you can basically see that -- the

extent of it -- it pretty much covers most of the area where

our chlorinated VOCs are found. And the green is the benzene

contamination; the purple or red areas show where free product

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petroleum was measured back in 2007. It floats on the water

table and the UST program measures regularly the thickness of

that product in the wells that they have out there. So, this

was in 2007, these are the various places where there's

floating petroleum product in groundwater inOU14. In surface

water and sediment, we mentioned that one unnamed stream down

here. This is a photograph of it so you can see what it looks

like up close. We were interested in sampling here because we

wanted to make -- we wanted to see whether or not contaminants

from the plumes were reaching and impacting this stream. So, we

collected surface water and sediment samples up and down the

length of it. And, basically, in surface water, we did find

trace levels of TCE and 1,2-DCE, but they were well below

regulatory standards. We found TCE at a maximum of 0.19

microgram per liter. The State's surface water standard is 30.

1,2-DCE, the maximum we found was 0.5 micrograms per liter.

There is no surface water standard, but the groundwater

standard is 70; so, well below any regulatory standards.

MS. McCLELLAN-GREEN: What about vinyl

chloride?

MR. BITTERMAN: Did not find any vinyl chloride;

undetected in all samples. Yeah, thank you, I did mean to say

that. And in sediment, we found no chlorinated VOCs in our

results. With regard to biodegradation, I mentioned that there

was wide spread presence of these daughter products. That's one

line of evidence that biodegradation is occurring. We also

collected samples for various -- what we call "Indicator"

Parameters. These are different metrics that helps us get an

idea whether conditions in the aquifer are right for

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biodegradation to occur. These include pH, dissolved oxygen,

total organic carbon, oxidation-reduction potential,

nitrite/nitrate, iron isotopes II/III, and sulfate and sulfide.

And not to get into any of the details of each one of those,

but in a nut shell, the results of those Indicator Parameters

show that conditions at OU14 were sufficient to ideal for

reductive dechlorination to occur. So, that was a second line

of evidence regarding biodegradation at OU14.So, a couple of

slides here just summarizing the big picture of what we found

in the RI at OU14. The conclusion was that the chlorinated

volatile organic compound plumes have stabilized and are

naturally attenuating. Now, what does that mean, stabilized? It

means that they're not increasing in spacial extent, and the

magnitude of the concentrations is also not increasing. We

found evidence that the chlorinated VOCs are biodegrading and

attenuating naturally. And as the plumes move downgrading

towards that unnamed stream, they biodegrade to below

regulatory standards before they reach that stream. We also did

biodegradation modeling to see whether or not in the future the

likelihood that they would reach the stream, and the results

of that modeling concluded that, in the future, none of those

constituents would reach the stream before they biodegraded to

below standards. And, again, I mention those indicator

parameters showed that the geochemical conditions were

sufficient to ideal for biodegradation in the aquifer. With

regard to human and ecological risks, we did find human health

risks at Operable Unit 14. With regard to the ground-water, the

only unacceptable risk was for a future resident scenario. In

other words, Operable Unit 14, either base housing were built

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there, or the air station closed and it became a subdivision,

and people installed wells and got potable water from the

Surficial Aquifer. That's the only scenario in which there's

unacceptable human health risk to groundwater. Now, that

scenario is not very likely to occur. There's no plan to close

the air station and since it's the flight line complex for the

air station, it's pretty unlikely that base housing would be

built for Operable Unit 14. But even if that were to occur,

it's still not very likely that anyone would ever use the

Surficial Aquifer as a potable groundwater source, because they

don't in North Carolina, in general, use it for anything more

than irrigation; other non potable uses. Because the natural

groundwater quality is not very good because of high levels of

inorganics, iron and manganese, in particular. Plus, the yields

that you get from wells are not generally sufficient for water

supply at a home or larger building. The other unacceptable –

potential unacceptable risk involved indoor air. We did not

find any risk for the existing buildings out there, based on

their location and the types of building. However, should a new

building be built or an existing building be modified in a

particular way, there is some possibility that an indoor air

risk would be created. What we're talking about here is the

volatilization, the contaminants moving up through the soil

column. Buildings with crawl spaces or basements tend to be the

more likely places where you get problems where the vapors

accumulate and then occupants of those buildings might breathe

those vapors. So, we didn't find any current risk for existing

buildings out there. However, depending on where a new building

might be built, or an existing building might be modified, it

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was identified that there's the potentially risk for that. For

ecological risk in that stream area, there were no risks found.

MS. McCLELLAN-GREEN: I'm a toxicologist, but

I'm more of a biologist then a chemist. What is the

transport rate for TCE in the soils here at Cherry Point?

'Cause you said you didn't find any soil contamination and

all of your figures show that it's in the water. So, it

must be going through quite rapidly. So what is the

transport rate?

MR. BITTERMAN: You mean the groundwater flow

rate?

MS. McCLELLAN-GREEN: The flow of these

chemicals through the sediment. Not the groundwater --

MR. BITTERMAN: Volatilizing up to --

MS. McCLELLAN-GREEN: -- well, you have none of it

in the soil you said. And all of your graphs show

none

of it in the top 20 feet.

MR. BITTERMAN: Of the groundwater --

MS. McCLELLAN-GREEN: Of the --

MR. BITTERMAN: -- of the soil?

MS. McCLELLAN-GREEN: -- of the soil. There's

nothing here; it all starts about 20 feet down. So, what's the

transport rate to the soil here on Cherry Point?

MS. GENA TOWNSEND: That we have not

calculated.

MR. BITTERMAN: Yeah, we did not collect --

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MS. TOWNSEND: But, we don't -- we really can't say

that the source started at the point where we have highest

concentration; it could have been lines of leaking that were

already there.

MS. McCLELLAN-GREEN: Yeah, yeah.

MS. TOWNSEND: Right.

MS. McCLELLAN-GREEN: That's why I'm wondering,

cause it's all well down below, so --


MS. McCLELLAN-GREEN: -- you can -- if these

values that you're saying are true, that there's none in

this soil up here --


MS. McCLELLAN-GREEN: -- then it's transported,

well, you said 30 to 60 years, who knows.

MS. TOWNSEND: Well, those are the degradation of

the chemical itself.

MS. McCLELLAN-GREEN: Yeah, so, either it's

degrading rapidly in the soil or it's being transported back

into the soil.

MR. DALE McFARLAND: Or it -- it was not released

as a chemical but as -- dissolved in the water --

MS. McCLELLAN-GREEN: Right.

MR. McFARLAND: -- and carried in the water

from the wash rack down to the water table.

MS. McCLELLAN-GREEN: What's the solubility of TCE

in the water?

MR. BITTERMAN: It's 400 milligrams per liter.

These compounds have moderate to low solubility. And they'd

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much rather be in the air --


MR. BITTERMAN: -- than in the water.


MR. GEORGE LANE: So, you can tell by the

picture they sink when they're not in the water.

MR. BITTERMAN: You have to keep in mind, too, that

there's a lot of petroleum contamination in the soil, which

might actually dissolve the TCE. It might have gotten down

there faster by --

MS. McCLELLAN-GREEN: Yeah, see that's why I'm

wondering -- it just went (whoosh) straight through?

MR. BITTERMAN: -- the presence of petroleum.

MS. McCLELLAN-GREEN: Well, there's an active

bacterial culture in the sediments, that, you know, it still

went through quickly, but what remained behind was slower --got

chewed up faster, so. Yeah, that's just the scientist in me

coming out. Thank you.

MR. BITTERMAN: Okay. At the conclusion of the

remedial investigation, the team formulated remedial action

objectives, or RAOs, to address those risks – those potential

risks that I mentioned. And this is what we came up with for

ground water, surficial aquifer groundwater. To prevent human

exposure to the contaminants in the surficial aquifer

groundwater containing chemicals of concern, or COCs, is the

term that we tend to use. Reduce those COCs to cleanup levels.

Achieve suitability of OU14 groundwater for unlimited use with

a reasonable approach and within a reasonable time frame. To

prevent -- and then prevent migration and discharge of those

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COCs into that unnamed stream, such that it would cause

unacceptable risks to human or ecological receptors. So, those

were the RAOs for surficial aquifer groundwater. For indoor air

vapor, the RAO was to prevent unacceptable risks to human

receptors from exposure to indoor air vapors resulting from

sub-surface contaminants of concern.

MS. McCLELLAN-GREEN: Do the occupational health

-- does that office monitor for concrete cracks in the

building? 'Cause I assuming you all have concrete floors.

MR. BITTERMAN: I believe they're slabs,

concrete slabs, most of the foundations. I have no

knowledge of whether they make records.

MS. TOWNSEND: Yeah, that would have to be a base

process on that -- but most of those buildings are wide open

hangars.

MS. McCLELLAN-GREEN: Yeah, that's why you're not

seeing any.


MS. McCLELLAN-GREEN: I was just wondering.

MR. BITTERMAN: We looked at the --

MS. McCLELLAN-GREEN: Ya'll did air samples,

right?

MR. BITTERMAN: -- locations of the buildings with

respect to the contamination, and then the types of the

buildings -- what kind of foundation it had. And, basically,

all the existing buildings didn't get over that hump to get to

the next level where you might take samples, of soil gas or

indoor air. So, the conservative screening values were all

safely within bounds just at that level.

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MR. BITTERMAN: But, you know, depending on the

location of a new building, that may not be the case; that was

in the caveat for indoor air.

MS. ERICA DeLATTRE: And part of the reason it

fell out of the process was that the levels of the

contamination in this area --

MR. BITTERMAN: Yeah,

MS. DeLATTRE: -- is whether it's higher

contamination than the groundwater. You may have to go that

extra step with the same type of rule.

MR. BITTERMAN: If you remember from the plume

map, the area where it's really either moderate or high is

very small, relative to the total plume. This is a list of

the chemicals of concern that were identified from the

remedial investigation. It also shows the groundwater

remediation goals. For each of those, with one exception,

those goals are the North Carolina Groundwater Quality

Standard. Bromomethane, the first compound listed there, which

was very infrequently detected, does not have a North Carolina

Groundwater Quality Standard. So, we developed a risk-based

remediation goal from the human health risk assessment, and

that's what the asterisk is to refer to. But all the other

remediation goals are the North Carolina Groundwater Quality

Standards.

So, after the RI and the development of the RAOs and

identifying the COCs, it was time to do the Feasibility Study;

developing clean-up alternatives and then evaluating and

comparing the different alternatives. So, I'll start off just

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by listing all of the alternatives and then we'll go into more

detail about each one. Whenever you do a feasibility study,

the first alternative is always no action required under

CERCLA. So, that was Alternative 1.Alternative 2 is Land Use

Controls, or LUCs [“Lukes”] or LUCKs [“lucks”]. Those are

administrative restrictions, institutional controls that

restrict access to a site or prohibit the use of groundwater

and things like that. Alternative 3 also includes the Land Use

Controls, but it adds Monitored Natural Attenuation. It's

allowing the contaminants to naturally attenuate, but you have

a regular and formal monitoring program to assess the progress

of the attenuation. Alternatives 4 and 5 have both the

Monitored Natural Attenuation and the Land Use Controls, but

they add a treatment component to the areas where the

contaminant concentrations are highest. Alternative 4 has a

technology called biosparge, which is injecting air into the

aquifer at a relatively low rate to physically volatize the

chlorinated VOCs and promote aerobic biodegradation, which

does work, but not as effectively as anaerobic. It's the

stripping that's really the most important process for

biosparging. And then, Alternative5, instead of biosparge, has

Enhanced Reductive Dechlorination as the technology. That's

basically injecting a substrate, a liquid substrate into the

aquifer, that provides the nutrients and the components that

make the conditions as ideal as possible for dechlorination

and biodegradation to occur -- to try to really speed up that

process. So, those are the 5 alternatives we looked at.

Now, to evaluate them, there are a set of nine

evaluation criteria that are defined in what's called the

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National Oil and Hazardous Substances Pollution Contingency

Plan, or NCP, as I refer to it. There are nine evaluation

criteria defined in that regulation. And those nine criteria

are grouped into three groupings. The first grouping contains

two of those criteria and it's called the Threshold Criteria.

And these are pass/fail criteria and they represent the minimum

compliance. If you don't meet the threshold criteria, then you

can no longer consider those alternatives. The two threshold

criteria are overall protection of human health and the

environment and compliance with what are called ARARs --

Applicable or Relevant and Appropriate Requirements, which are,

basically, State, Federal Groundwater Standards, Regulations -

being in compliance with those things. So, those are the -

that’s the first hurdle of the two threshold criteria. Any

alternatives that pass that hurdle move on to the grouping

of the next five criteria, which are called the Primary

Balancing Criteria. These are not pass/fail. This is

really the meat of the evaluation. This is where the

different alternatives, some will score higher with one

versus the other. And you, basically, do a very detailed

evaluation to see how each of the alternatives score with

respect to these five criteria. And, they're fairly self-

evident, long-term effectiveness and permanence; reduction

in toxicity, mobility, or volume through treatment;

implementability; short-term effectiveness; and, finally,

cost.

Now, the preferred alternative is actually selected

based on this first set of criteria. The last two of the nine

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are actually -- actually come into play after the receipt of

public comments on the proposed plan. And they are called the

modifying criteria. And it's acceptance by the State and

acceptance by the community. The State actually reserves

judgment officially until public comments are received on their

acceptance of the preferred alternative, and then, obviously,

any public comments. So, based on the feedback from that, the

preferred alternative may be modified or even replaced with

another alternative based on that comment. So, these two come

into play based on public comments. So, that is the evaluation

process that we have undergone.

Now, I'm going to go through each of the alternatives

and start telling you about our evaluation, provide a little

bit more detail about each one. Starting with no action,

Alternative 1. As I said, it’s required to be considered; it

basically means doing absolutely nothing, walking away, no

restrictions whatsoever on access or activities at the site.

No monitoring; you're done. Obviously, this alternative does

not comply with the threshold criteria because there's

absolutely no restriction to exposure to the contaminants. So,

it does not protect against human health. It does not protect

human health and the environment, because there's no

prohibition on someone putting in a well and drinking the

water. It does not comply with ARARs because the State

Groundwater Standards are not being met or addressed in any

way. So, Alternative1 is out for further consideration. It

does not meet those threshold criteria.

Alternative 2, the Land Use Controls, they prevent

human exposure to the contaminants by restricting access to

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them, in indoor air and groundwater. Now, the specifics of the

Land Use Controls are not developed until the remedial design

phase. But the team has talked about what kinds of Land Use

Controls would be required for OU14, and there are basically

two kinds -- a restriction on groundwater access, prohibition

on using groundwater, and then, secondly, in the event that a

new building or an existing building is to be modified within

the contaminated areas of OU14, there would need to be a

process to evaluate whether or not there's any likelihood of an

indoor air vapor problem being the result of that. So, those

are the kinds of Land Use Controls that we're talking about.

Now, obviously, under this alternative, natural attenuation

would still be occurring in the groundwater, however, there's

no monitoring program. So, there would be no idea whether or

not at any particular point and time -- cleanup goals had been

met, or whether risks still remain. So, for that reason, this

alternative Land Use Control alone does not meet the threshold

criteria. It is also out for further consideration. Lack of

monitoring is the main reason for that. The Land Use Controls

are still an important thing, though. This Land Use Control

alone do not meet the threshold criteria.

However, Alternative 3 keeps those Land Use Controls

but adds to it Monitored Natural Attenuation. That's basically

a formal, regular monitoring program to sample for the

contaminants of concern throughout the natural attenuation

process until groundwater clean-up goals have been met. We

would install additional monitoring wells to create the best

possible monitoring network, and prepare a plan to collect COC

samples and also indicator parameter samples over time. The

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remedy includes land use controls which is what prevents

exposure during the time that the plumes are natural

attenuating. So, this alternative does meet the threshold

criteria, because the Land Use Controls restrict access to the

contaminants. So, that prevents --protects human health and

the environment. And then, overtime, those remedial action

objectives are met through natural attenuation. So, it does

meet threshold criteria. We have not done a very rigorous

study to try to estimate precisely how long we think the

natural attenuation process will take at OU14, but very

conservatively, we are projecting that it could take as many

as 100 years.

MS. McCLELLAN-GREEN: Ya'll haven't modeled

that out?

MR. BITTERMAN: We don't have enough data, over a

long enough period of time to come up with a better estimate.

If we were to implement this, we would get that data and be

able to come up with a better one. We're pretty sure it's

going to be less -- that or less. That's the, kind of the

worse case scenario, if you want to say. It doesn't take into

account a couple of factors that may be in our favor to

shorten that time frame, but just because there's no

analytical process to factor in these other factors. It has to

do with the petroleum contamination. I mentioned before that

where it's co-mingled with chlorinated VOCs, it can actually

enhance that biodegradation. So, our estimate of the

biodegradation did not factor that beneficial influence in

whatsoever. It just looked at that biodegradation in the

absence of any enhancement like that. Then, secondly, in this

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pink area, which you probably can't see in this figure, but

it's sort of a box here, within this box there are a number of

air sparge wells; I don't know how many. Erica, do you know

the approximate number?

MS. DeLATTRE: I --

MS. McCLELLAN-GREEN: And that's for the

petroleum guide?

MR. BITTERMAN: For petroleum, and then, also, I

think --

MS. DeLATTRE: Yeah, there's six up there.

MR. BITTERMAN: But air sparging strips out

chlorinated volatiles, as well as, petroleum volatiles. So, to

the extent that their system corresponds with the chlorinated

VOCs, there is some treatment from the existing systems out

there. We haven't factored that in either.

Alternative 4 includes the Monitored Natural

Attenuation and the Land Use Controls. Because the plume area,

you know, this is a couple of thousand feet here; this whole

length is a huge distance. The area of the plume is way too big

for it to be feasible to literally treat every square foot of

the plume. The cost would be unimaginable. So, all you can

feasibly do is treat the higher concentration areas in order to

reduce the natural attenuation time frame. So, Alternatives 4

and 5 have a treatment technology to do that. Alternative 4 is

the biosparge technology, injecting air into the groundwater.

The concept we laid out that we think is the best for this

scenario, is to install horizontal injection wells along the

access of the plume in the areas of the highest concentration.

And the photos -- this is a drill rig for installing a

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horizontal well, and this is a closeup. It's hard to see, but

there's actually slots in this high-density polyethylene pipe

that are slits that are along the length of it, and that's

where the air would bubble up into the aquifer. This shows

basically a conceptual layout of where these horizontal wells

would be, these black lines that the arrows, the red arrows

point to. And, basically, we have a concept of four horizontal

wells that would be for biosparging in the areas where the

plume concentrations were relatively the highest. And this just

shows you at other sites of pictures of biosparging equipment,

some of the control system. Here's a portable blower or

injection system at another military facility somewhere.

MS. McCLELLAN-GREEN: Will vents be added to the

concrete -- if this alternative is done?

MR. BITTERMAN: Yeah, we'll talk about

implementability in a minute, but we would have to basically

have a subterranean vault in with some of this equipment,

because it can't just be sticking up out of the ground in the

middle of the taxi way. It's a lot easier in sites like this

where you can just have it come up from the grass off to the

side. As I said before, this alternative does also include

Monitored Natural Attenuation and Land Use Controls. Monitored

Natural Attenuation would be for those fringe areas of the

plume that are not receiving the direct treatment. The

technology does meet the threshold criteria. Like Alternative

3, the exposure pathways are restricted by the LUCs during the

remediation time. And, eventually, those remedial action

objections will be met through the combination of treatment and

natural attenuation. We estimate approximately 40 years for

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this scenario. It would reduce the time frame to about 40

years. And here's a picture of some other base, this is where

the horizontal well comes up out of the ground and they're just

beginning to install the injection. This is basically the

control room where they're going to put the equipment. So, this

is so you can see what it would look like. But it would be more

difficult at OU14; you couldn't just put a box like that out in

the middle of a flight line area.

MS. McCLELLAN-GREEN: No.

MR. BITTERMAN: Okay. Alternative 5, instead of

biosparging, uses this Enhanced Reductive Dechlorination or

ERD. It's injecting organic substrate, things like vegetable

oil, molasses, or different substrates, but there are companies

that have proprietary formulations that are optimized to get

the best results. So, in the higher concentration areas, you

would inject the substrate. Well, actually, you would first

install a series of injection wells to get the coverage that

you wanted. And you would have to do multiple phases of

injections to get the kind of treatment that you needed. So, we

would have to install vertical injection wells, and then do two

to three injections phases. This remedy also includes Monitored

Natural Attenuation and the LUCs, as do the other alternatives

to prevent exposures while the treatment and attenuation is

occurring. This shows the concept here, unlike the biosparge

where the alignments were parallel to the flow, the idea for

ERD is more of creating these alignments that are perpendicular

to flow, where you inject the substrate in the groundwater so

that it moves through that zone and gets revved up for

biodegradation. So, there's a concept of about six areas where

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there would be injection alignments. This gives you and idea of

what atypical injection well looks like at some other military

facility. Here, this is actually showing the injection, the

tanks holding the substrate and the pumps that inject it down

into the well. So, that's kind of what it would like. This

would have to be subterranean though, at OU14. This alternative

also meets the threshold criteria similar to Alternative 4. The

time estimated on this alternative is 60 years. And here is a

photo, and you can kind of see a series of injection wells in

parallel alignments. Sort of the same kind of concept we have

for OU14, except for they would have to be subterranean. And

here is just another injection cart, and some of that

equipment.

So, I've gone through each of the alternatives;

Alternatives, 3, 4 and 5 met the threshold criteria. So,

they're still in the running. Alternatives 1 and 2 did not, so,

they're are out of the running for an alternative. So, we're

moving on now to the primary balancing criteria. I have a

series of slides -- and I basically have one slide per

criterion. And there's a table that compares each of the three

viable alternatives with respect to that criterion. And I just

want to tell you that the tables that I show here are distilled

down from significantly more detailed tables in the feasibility

study. Pages with long and tremendous detail. This has been

distilled down to the essence of the findings of our

evaluation. So, if you're interested in seeing the full detail,

the glorious detail, the feasibility study has it -- a table in

four of five pages of great detail.

Okay, so starting with the first primary balancing

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criterion, long-term effectiveness and permanence. I also show

on these slides in a little bit more detail of what is involved

in these criteria. That's what these bullets are up here. This

one gets to the magnitude of any residual risks. That is, if

after the treatment or after the remedy is complete, you still

have some remaining contamination left, the adequacy and

reliability of the controls and then the type and degree of

monitoring and O&M, operation and maintenance, that the remedy

involves. So, it's actually nota whole great deal of

difference between Alternatives 3, 4and 5 with respect to this

criteria. They are all effective and permanent; at the end,

there is no residual risk remaining. Same for all three of

them. With respect to the monitoring and operation and

maintenance, the least amount is with Alternative 3, the

Monitored Natural Attenuation. Alternatives 4 and 5 have that

same amount plus operation and maintenance of the treatment

systems. Alternative 4 would have the greatest amount because

you actually have a system that requires power and a continuous

operation. Alternative 5, where you're just injecting every

couple of years, has less; but still more than Alternative 3.

All in all, there's not a whole great deal of difference with

respect to this criterion.

The next primary balancing criterion is reduction of

toxicity, mobility, or volume through treatment. And that gets

to the extent that the mass and the volume and the mobility is

reduced by the remedy; the type and quantity of any residuals

that remain; and in this case, there would not be any. And then

the extent to which the scope of the action reduces the hazards

out there. And there's not a tremendous amount of difference

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between these three alternatives with respect to this criterion

either. They all achieve reduction over time via natural

attenuation of the contamination. Alternatives 4 and 5 add to

it treatment, either through volatilization and aerobic

biodegradation for the biosparge, or anaerobic biodegradation

for the ERD. All of them over time achieve the same end.

The third primary balancing criterion is short-term

effectiveness. And this gets to whether or not during the

construction or implementation there are any issues with

protecting the community or the workers that are actually doing

the work; environmental impacts from the construction. Some

alternatives, like if you're doing it -- digging up

contamination, you might act to deforest an area in order to do

that. It looks at things like that. The short-term

effectiveness is where you actually get to the time frame for

achieving the remediation. So, with respect to protecting

workers during implementation, they're really pretty much the

same; standard engineering safety controls will protect the

workers doing this kind of work for all of them. With respect

to the time frame, the Monitored Natural Attenuation alone,

obviously, has the longest time frame --it -- you know, up to

100 years. Alternatives 4 and 5 reduce that to approximately 40

or 60 years, respectively.

Getting into implementability, this criterion gets into

the technical feasibility, how much of a challenge it is to

construct, how reliable the technology is, how much monitoring

is needed. Administrative feasibility is how much red tape and

administrative work you have to go through to implement the

remedy where there's lots of permits and things like that. And

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then, finally, the availability of the services. Will you have

to go to Sweden to get someone to come in for this technology

or is it widely available at your location. So, those are the

kind of issues that this criterion gets to. There's a fair

amount of difference between these alternatives with respect to

this criterion. They're all implementable; there's no doubt

about it. The technology exists and it can be done. The easiest

to implement, obviously, is the Monitored Natural Attenuation

and LUCs alone. The services and the materials to do that are

all readily available. Alternative 4 is the most technically

challenging of all of them, because it's an active system that

requires ongoing power. And you would drill these horizontal

wells and there's a lot of utilities, as you can imagine out at

OU14. And because of the nature of the site with the flight

line and all the military activities, it would be very

challenging to implement that and not disrupt their operations.

You have to -- you'd have to go beyond the normal design to

make things subterranean so that the aircraft could ride over

the vaults where you have air sparging going on. So, it can be

done, but it's definitely more challenging than the other

alternatives. There's also an increased risk of air vapor being

caused by this. It's not really -- I don't want to exaggerate

the risk because we don't think it's really that great of a

risk. But, because you're injecting air into the aquifer,

you're going to be volatizing the chlorinated VOCs into the

soil gas, which is going to be rising up toward the atmosphere.

The buildings at OU14 are not immediately adjacent to any of

these proposed injection areas. However, keep in mind, the

whole operable unit almost is covered with pavement and

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concrete. And sometimes, strange things can happen when the

soil gas cannot readily vent to the atmosphere because of the

barrier of the pavement. So, occasionally, you can get strange

things happening. So, some increased risk; we don't want to

over state it, but just wanted to point out that there is

increased risk in the air vapor with this alternative. There's

also the possibility that it may interfere with the UST

programs remediation systems. When you inject air into the

aquifer -- we saw this at the site 16 air sparge system. That

the injection causes the groundwater table to mound up from all

that air bubbling up. And there's free product in some of the

areas where we would be doing this injection. And that

groundwater mounding would tend to disperse or potentially

spread that pool of petroleum. It would be a temporary effect

because we don't inject -- the injection rates are fairly low

for biosparge; it probably would be a temporary effect. But

there might be some tripping over each other, trying to

remediate our various issues caused by this alternative.

MS. McCLELLAN-GREEN: Didn't you say that UST

program was already doing some of that?

MR. BITTERMAN: They are doing it --

MS. McCLELLAN-GREEN: In some areas?

MR. BITTERMAN: -- in some places. But we maybe

doing it in places where they don't want to do it. Because

they -- they do free product recovery, pumping it out, as

well, in some places.

MS. DeLATTRE: In one area, they purposely

mound the groundwater in one spot to prevent the product

from moving to that area. So, they actually use it as

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almost a wall or control.

MR. BITTERMAN: I don't want to overstate this one

either, but -- because we think this is a minor concern, but

it is an issue. Alternative 5 is easier than 4, but it's more

challenging than 3, because you're doing these one-time

injections, so going out and installing all these vertical

injection wells would, obviously, be challenging to coordinate

with the flight line activities. But once they're in, then

there's not daily activities at them. You do injections every

couple of years or something like that. So, it is challenging,

but it's less than 4, more than 3. Now, one risk that we are

concerned about with Alternative 5 is that these air sparge

systems that UST program has out there, they tend to make the

aquifer aerobic, because they're blowing air through the

aquifer. ERD depends on the development of anaerobic

conditions, so it is possible that where we're in the same

area, that their systems might impede the ability of ERD to

function properly. So, that was identified as a concern with

Alternative 5.

And then the final primary balancing criterion is cost, and

these are rough order of magnitude cost. They're called minus

30 percent, plus 50 percent, meaning that it could be as much

as 50% more or as much as 30% less, depending on actual

circumstances when you do the work. All of these costs, the

future costs have been discounted into2009 dollars. So, the

actual absolute cost will be considerably higher, because

money, 30, 40, 50 years from now discounted back in 2009 is not

very much. So, they're all discounted to 2009 in order to be

able to compare them. We've included the two nonviable

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alternatives just – just for comparison. Obviously, the no

action is zero dollars. But the Land Use Controls -- the

purpose of including that is just to give you an idea of what

portion of these other costs are related to maintaining the

Land Use Controls. The cost of that is just having Jeff's time

and others' time in those inspections, and there's

administrative procedures that have to occur to document and

administer those Land Use Controls. And over a long period of

time, it adds up to more money than you might expect. But,

basically, with respect to the three viable alternatives,

Alternative 3,Monitored Natural Attenuation, is expected to

have a present value cost at just over 2 million dollars. Then

Alternatives 4 and 5 are considerably more; 3 million more for

the biosparge option, for a little over 5 million; and

4.2 million more -- 4.1 million more for Alternative 5, at

6.2 million dollars.

So, based on all this evaluation, the team has

determined that the preferred alternative for OU14 site 90is

Alternative 3, the Monitored Natural Attenuation and LUCs, and

there's a number or reasons why this alternative was selected.

The first are that the human health and ecological risk

assessments showed that there were no risks to current

receptors at the site, and the only unacceptable human health

risks were for a future residential scenario that is actually

very unlikely to occur. And, with respect to the indoor air,

it would only be potentially – and that's not even a sure,

depending on where and what type building would be

constructed. The land use control portion of the remedy

eliminates the potential exposure pathway to the contaminants

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throughout the life of that remedy. The RI results show that

the plumes have stabilized and they are naturally degrading,

and that no impacts to that stream downgradient are expected

throughout the period of natural attenuation. So, the

alternative would achieve the RAOs over time and the Land Use

Controls would keep it fully protective of human health and

the environment throughout that time. Alternative 3, also,

has the least significant implementability concerns,

disruptions to the flight line and military activities.

Potential for Alternative 4 to increase indoor air

concentrations could possibly negatively impact the UST

program and their remediation systems was a concern.

Alternative 5, a concern was the influence of those UST

programs systems on impeding the ERD, through creating aerobic

conditions was a concern for that one. Alternative 3 was by

far the most cost-effective of the alternatives. It's

recognized that the time frame for remediation is longer

relative to the other viable alternatives. However, that is a

somewhat pessimistic timeframe, and does not account for the

beneficial influence of the petroleum contamination and the

petroleum remediation systems might have in reducing that time

frame. And, basically, in a nut shell, the team concluded that

that alternative had the best balance of trade-offs among the

various criteria among the different alternatives.

So, in closing, I'd like to remind everyone about the

public comment period extends until June 15, and if you would

like to review any of those source documents, the website --

have you ever gone into the web site records?

MS. McCLELLAN-GREEN: Oh, yeah.

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MR. BITTERMAN: Okay, good. Available online -- if

you want to submit any written comments, we try to make it as

easy as possible. The proposed plan, the very last page,

there's a comment form and you can just rip it out and fold it

in half, it's already addressed.

MS. McCLELLAN-GREEN: You can just send it in.

MR. BITTERMAN: Just send it in. So, feel free to

do that up until June 15. And with that, I thank you for your

patience and if anyone has any final questions?

MS. McCLELLAN-GREEN: Are any of -- are any of the

activities -- at the wash racks or any of the places there,

likely to inhibit the growth of the bacteria that you're

relying on for natural attenuation?

MR. BITTERMAN: No reason to believe that they

would.

MS. McCLELLAN-GREEN: Do you know what chemicals

are used --

MR. BITTERMAN: I'm trying to think how they

would.

MS. McCLELLAN-GREEN: -- cleaning with now?

MR. McFARLAND: They shouldn't be using any

chemical -- just soaps, surfactants are the other thing.

MS. McCLELLAN-GREEN: Well, surfactants are anti-

bacterial, so.

MS. TOWNSEND: But the -- the wash racks should be

draining into --

MS. McCLELLAN-GREEN: Yeah, should be. That's why

I'm asking. Do you know that there's not any impact on what's

going on now or when these new FAP, or whatever, we get here?

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'Cause they'll be --

MR. BITTERMAN: -- all I can say is that it hasn't

manifested to date.


MR. BITTERMAN: You know, there's no evidence that

attenuation -- those indicator parameters, for example, would

turn negative if -- right at this moment – the conditions had

changed. We don't have -- we don't see that. The indicator

parameters were actually one of the more recent data that we

collected. And we would continue to collect it over time.

MS. TOWNSEND: Yeah, we didn't pick up any

strange compounds in our sampling --


MS. TOWNSEND: -- we've seen typical of what we

would expect to see.

MS. McCLELLAN-GREEN: What you would expect to see?

MR. BITTERMAN: And -- and I didn't say this, but

the places where we found the conditions to be most ideal were

where the concentrations were the highest.

MS. McCLELLAN-GREEN: Okay. So, it seems to be

degrading in those areas more rapidly than the other areas?

MR. BITTERMAN: I think it's because, you know,

where the concentrations are higher, there's -- there's more

food for the bacteria, so they get -- they get revved up.

MS. McCLELLAN-GREEN: Yeah, so --

MR. McFARLAND: What is the -- what is the typical

groundwater flowing through this area? I mean, what's their

essential cycle like?

MR. TIM WENK: Is it 40 feet a year or something?

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MR. BILL HANNAH: It's about 22 feet per year.

MR. BITTERMAN: It's still a long time, cause it's

a few thousand feet for the whole length of the --

MR. McFARLAND: So, now, what -- what's getting--

what we're getting released at the wash rack today, is not

going to have an impact on the plume area --

MS. McCLELLAN-GREEN: Well, I'm not thinking that

it's going to add to the plume; what I'm thinking is that maybe

something is going to inhibit the bacteria that you're relying

on to degrade your product.

MS. TOWNSEND: We haven't seen that, and that's

why we collected the natural attenuation parameters, to make

sure that conditions are right.

MR. BITTERMAN: The monitored natural attenuation

would be we'd be constantly inputting data and evaluating the

trends, and in the five-year review, it would have to continue

to be shown as a viable option if it -- there was evidence that

it was slowing down, or stopping, or stalling, then the team

would have to reconsider.

MS. McCLELLAN-GREEN: And as the chlorines are

released, you're not seeing any change in the pH in the soil;

that sort of buffering factor you get?

MR. BITTERMAN: Not the groundwater pH, no.

MR. BILL HANNAH: You also asked about the TCE

solubility -- it's 1100 milligrams a liter.

MR. CHRISTOPHER: Well, thank you very much Doug.

And if there are no more questions, like Doug said, you have up

until the 15th of next month, June, you can get any comments

in. And I have nothing else to say, so, does anyone else have

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anything else to say? What's that?

MS. McCLELLAN-GREEN: What's the solubility of TCE

in petroleum product?

MR. BITTERMAN: I'd have to look that up.

MS. McCLELLAN-GREEN: What's the solvent in the

solvents. So, that would be actually more advantageous to you

because as they're pulling off product, they're decreasing your

contaminant.

MR. McFARLAND: You're watching the soil for --

MR. LANE: The real reason the petroleum is helping

us is -- the benzene -- they actually like the benzene better

than they do our kind.

MS. McCLELLAN-GREEN: The chlorines will kill the

bacteria.

MR. LANE: Yeah, the benzene helps the population

to grow faster, so if you get a bigger – it grows faster, it

has to eat something, so it eats the chlorine, the entire

product.

MS. McCLELLAN-GREEN: So, you want to slow them

down on there until you get rid of your stuff, right?

MR. LANE: Oh, it's going to be there for awhile;

they've got plenty of product to go around.

MR. BITTERMAN: The petroleum contamination by

volume and mass is considerably greater than ours.

MS. McCLELLAN-GREEN: So, it would be pooling up in

the creek in another 50 years.

MS. DeLATTRE: That's why we have the air sparge

there to keep it from going into the creek.

MR. BITTERMAN: You have higher downgradient

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concentrations. Ours won't -- it shouldn't really go into

the stream.

MS. TOWNSEND: Yeah, free product shouldn't show up

in the stream.

MR. LANE: And a part of the remedy will be to put

up monitoring wells, so that we can measure the plume.

MS. McCLELLAN-GREEN: Uh-huh.

MR. LANE: So that we can monitor that plume as it

approaches and goes through there to make sure it's not

increasing.

MR. BITTERMAN: Right. More monitoring wells.

MS. McCLELLAN-GREEN: So, you're going to have some

down on the other side.

MR. BITTERMAN: Yeah, we'll probably -- I mean,

there's already -- the figure shows wells, but there's already

wells on both sides that we'll probably add. So, we really have

it covered thoroughly --


MR. BITTERMAN: -- through the long-term

monitoring.

MS. McCLELLAN-GREEN: Will ya'll do liquid sampling

or use passive sampling devices, or what are you doing?

MS. TOWNSEND: We'll probably will – since they're

chlorinated -- we'll probably go to passive samples; they're

easier, and you get a better picture --

MS. McCLELLAN-GREEN: Yeah. That's what I was

wondering.

MR. CHRISTOPHER: Anything else? Okay. Well, if you

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1 do have questions, you can give me a call. Well, thank you very

2 much. The meeting is adjourned.

3 ***** THE PUBLIC MEETING CONCLUDED AT 7:45 P.M.

4 *****

49

Documents

RECORD OF DECISION (RODS) - Records Collections · 2017. 5. 12. · 2 DECISION SUMMARY In 1994, MCAS Cherry Point was placed on USEPA’s NPL, established under CERCLA §105(a) for