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Site 1 - Camp Allen Landfill
The CALF site includes two distinct areas (Area A, the 45‐acre landfill, and Area B, the 2‐acre fire disposal area) is located within the Naval Support activity, as shown in the figure below. The Area A landfill, which operated from the mid‐1940s until approximately 1974, was used for the disposal of metal plating and parts cleaning sludge, paint‐stripping residue, various chlorinated organic solvents, overage chemicals, pesticides, asbestos, incinerator ash, fly and bottom ash from the base power plant, and miscellaneous debris. Wastes from a fire at CASY (Site 22), including drums containing various chemicals, were buried in 1971 in trenches at Area B.
The primary contaminants found in all media at the site are volatile organic compounds (VOCs). Areas of inorganic contamination in surface water and sediments in the surrounding drainage ditches and in the onsite pond were also identified. Groundwater contamination was found in both the Columbia aquifer (the shallow, water table aquifer) and the Yorktown aquifer (the deep groundwater aquifer) in Areas A and B. The presence of contamination in the deeper Yorktown aquifer is thought to be due to the presence of a discontinuous confining layer between the two aquifers beneath much of the CALF area.
The primary remedial action at the site consist of the ongoing operation of the groundwater extraction and treatment system began in November 1998 and consists of pump‐and‐treat systems for groundwater remediation installed in Area A (for Yorktown aquifer groundwater in the western part of the area and for Columbia aquifer groundwater in the northern part of the area) and in Area B (for both Columbia and Yorktown aquifer groundwater). ICs currently in place at CALF include prohibitions of the use of groundwater for any purpose other than environmental monitoring, as well as digging prohibitions that are enforced using a dig permit system and the Navy’s site approval process.
Although the current remedial actions at Site 1 are protective of human health and the environment, a Remediation Optimization Investigation will be conducted in early 2019 to further characterize contaminant plume migration and to evaluate additional remedial alternatives to expedite the reduction of COC concentrations within the groundwater.
Site 2 ‐ Naval Magazine Slag Pile
The NM Slag Pile (Figure 2‐2) is a 1‐acre disposal area for slag generated by an aluminum smelting operation during the 1950s and 1960s. The slag is a residual cinder material formed from fusion rocks such as limestone with impurities from the aluminum ore and ash from the blast furnace fuel. To create a level surface upon which the slag could be deposited, fly ash and/or bottom ash (derived from coal burning operations elsewhere at NSN) was also used as fill material at the site. During the smelting operation, the slag pile area was defined by a lack of vegetation around the site near the slag pile. The site surface has since been regraded and vegetation planted. Prior to remediation activities, the surface of the site consisted of a gravel parking lot and an open grassy field.
The 1998 RI conducted at the site concluded that the disposal activities had impacted the groundwater and soil at the site, as well as sediment and surface water in the adjacent drainage channel. In correlation with the type of material disposed at the site, the primary contaminants consist of metals including arsenic, antimony, cadmium, chromium, copper, iron, lead, nickel, silver, and zinc. However, significant concentrations of organic chemicals (4,4’‐dichlorodiphenyldichloroethene and trichloroethene [TCE]) were also detected. Sediment and surface soil sampling was conducted in February of 1998 to delineate the contamination limits for a sediment removal action.
The final Remedial Action Design for the sediment removal program was submitted (CH2M, 1999), and approximately 2,000 cubic yards (yd3) of sediment were removed in November 1999. The final ROD was completed in December 2000 (CH2M, 2000a). In February 2000, an asphalt and soil cover remedy was placed over the site.
Annual long‐term monitoring of the groundwater will continue at Site 2 to assess the effectiveness of the remedy in reducing the COC concentrations within the groundwater.
Site 3 - Q‐Area Drum Storage Yard
The QADSY, shown on Figure 2-3 below, was previously a compound that occupied approximately 5 acres in the northwest corner of the NSN near the carrier piers. This area of the NSN was created by dredging operations in the early 1950s as the base expanded in area. The QADSY was an open earthen yard that was used from the 1950s until the late 1980s to store tens of thousands of drums. Most of the drums contained new petroleum products, various chlorinated organic solvents, paint thinners, and pesticides. Previous investigations showed dark stains on the soil and oil‐saturated soil throughout the storage yard, indicating past spills. The northern portion of the yard, which was used to store leaking or damaged drums and hazardous materials, was particularly stained.
In 1986, Navy fire inspectors expressed concern with the oil‐saturated soils at the northern end of the storage area (previously used to store damaged or leaking drums). Based on a potential fire hazard, the top 6 inches of soil were excavated from an area of 4,240 square yards (totaling approximately 750 yd3 of soil removed) in the northern section and disposed offsite in 1987. Following the removal action, this area of the storage yard was paved.
The DD (ESE, 1996b) for the site was signed in November 1996 and calls for remediation by AS/SVE. A pilot treatability study was performed prior to the system being constructed. The remediation system began operation in August 1998. Several monitoring wells were sampled for VOCs in 1998 to provide baseline water‐quality data before the remediation system was started. LTM for the QADSY has historically been (from 1999 through 2012) on a biannual sampling schedule for VOCs. Based on the significant reduction of VOC concentrations during the first year of operation, the system operation was modified during September 1999 to a 2‐week cycle of pulsing. Based on Team discussion of the groundwater data collected in 2012, the systems at AOC 1 and AOC 2 were shut down in June 2013 while LTM continues. The 2017 LTM data indicated that COCs exceeded their cleanup goals in nine monitoring wells, however, the concentrations were relatively low and mostly within an order of magnitude of the cleanup goals. In addition, the current LUCs and ICs are protective of human health and the environment. Based on this information the NSN partnering team agreed that the re‐activation of the AS/VES was not warranted at this time. LTM will continue to assess remedy effectiveness and future optimization.
Site 6 - CD Landfill
The CD Landfill site occupies approximately 22 acres and is located just east of Hampton Boulevard and south of the Naval Exchange, as illustrated on Figure 2‐4 below. The site incorporates two areas of landfilling operations—the easternmost (unpermitted) section and the western (permitted) section. The unpermitted portion of the landfill operated from 1974 to 1979 and was used for demolition debris and inert solid waste, fly ash, and incinerator residue.
In October 1979, NAVFAC received a permit from the Virginia Department of Health to use the landfill (western portion) for disposal of demolition debris and other non‐putrescible wastes, excluding fly ash, incinerator residues, chemicals, and asbestos. Blasting grit used for sandblasting cadmium‐plated aircraft parts was deposited at the landfill until 1981, when the blasting grit was tested and found to exceed the USEPA Extraction Procedure toxicity limit for cadmium. The grit was classified as a hazardous waste and onsite disposal of the material ceased. Landfilling operations continued in the western portion of the site until 1987.
The results of several investigations (performed in 1993 and 1994) guided the scoping of the RI. The RI was completed in three separate rounds of sampling. Soil, sediment, groundwater, and surface water samples were collected. As a result of the RI/RA Report (Baker, 1995b), an FS (Baker, 1996b) was prepared in July 1996 to address contaminated media at the CD Landfill site. Potential risks associated with contaminants in the soil, sediments, and groundwater (including surface water) were identified, and these guided the development and evaluation of the media‐specific remedial action alternatives. In addition to the FS, a separate geostatistical analysis was performed to evaluate and better define the areas of sediment contamination.
A Proposed Remedial Action Plan for OU2 (Baker, 1998a) identified the preferred alternative, a synthetic flexible liner‐capping system with groundwater monitoring with ICs, for the CD Landfill. The final ROD was issued on September 28, 1998 (Baker, 1998b). The construction of the landfill cap was completed in December 1999. As a requirement of the VSMWR (Part D of 9 Virginia Administrative Code 20‐80‐270), the CD Landfill is part of the LTM program at NSN with groundwater and surface water monitoring, as well as annual.
The LTM requires that eight monitoring wells be sampled every five years for 10 Site COCs. The last monitoring event was completed in 2016. The 2016 LTM data shows that only one of the wells detected one COC (arsenic) at concentrations above the MCL. However, the arsenic concentration is lower that what was previously detected at the well in 2007. In addition, the data for the other COCs shows that there has not been exceedances of the MCLs/ACLs or significant increases in concentrations in any of the eight monitoring wells. As a result, no modifications to the remedy or the LTM program is warranted at this time.
Site 18 ‐ Former Naval Magazine Waste Storage Area
The NM Storage Area (Figure 2‐5 below) is in the southeastern corner of NSN and was used from 1975 to 1979 to store drums of hazardous waste, consisting of waste oil, metal plating solutions and sludges, chlorinated organic acids (including TCE and 1,1,1‐trichloroethane), and paint stripping solutions. Spillage of waste oil and hazardous wastes occurred in this area. A pit was excavated, and an existing drainage ditch was widened and lengthened to channel waste oil and contaminated runoff into an unlined pit. Oil and contaminated water were periodically pumped from the pit and transported to a wastewater treatment plant. Based on the analytical data and a preliminary monitored natural attenuation evaluation, it was determined that there is evidence for biodegradation of TCE at Site 18. An EE/CA (CH2M, 2008a) was finalized in March 2008, detailing an interim groundwater action which recommended the implementation of ERD to mitigate the potential human health risk, an interim action of injection was completed in July 2008 in accordance with the Final Non‐Time‐Critical Removal Action Work Plan, Site 18, Former Naval Magazine Waste Storage Area, Naval Station Norfolk, Norfolk, Virginia (AGVIQ/CH2M, 2008a). A Performance Monitoring Report documenting the effectiveness of the NTCRA was completed in December 2009. The report recommended an additional injection to encourage further reduction of VOCs in groundwater. The additional injection was implemented as an Addendum to the 2008 Action Memorandum in May 2010 (CH2MHILL, 2010b). Performance monitoring has been conducted through March 2013 to evaluate the effectiveness of the May 2010 injection. The Selected Remedy documented by the ROD is continued enhanced bioremediation with groundwater monitoring and LUCs. Additional injections may be necessary if cleanup goals are not met in a reasonable timeframe in accordance with the ROD.
The NSN Partnering Team evaluated the 2017 LTM site groundwater monitoring data and concluded that based on the low levels of VOCs detected additional injections were not warranted during 2018 (CH2M, 2018). During 2018 the Navy identified Site 18 as a potential source of PFAS constituents that will be evaluated as part of a base wide PFAS PA/SI in FY 2019. As a result, the need for any substrate injections or modifications to the existing LTM will be evaluated following the completion of the PA/SI.
Site 20 - LP‐20 Site
As shown on Figure 2‐6 below, Building LP‐20 is one of many large buildings located northwest of the NAS main runway. Currently, the building primarily houses the PWC’s Transportation Department. In the past, a portion of the building was used for aircraft engine overhaul and maintenance. Previous activities at the building included painting, X‐ray facilities, cleaning and blasting, and a metal‐plating operation. Waste products generated from these activities were transferred to the industrial wastewater treatment plant via underground piping. In addition, a large fuel storage area is also located south of the building. An underground pipeline extends from the Fuel Farm to buildings LP‐78 and LP‐176, located east of the site. Between the 1940s and 1990s, numerous spills or releases of wastewater and petroleum have been documented. Significant releases were associated with damage to underground wastewater lines during construction activities, and leakage of the underground petroleum pipeline.
Investigations at the site began in 1986 following a release of Jet Propulsion‐5 fuel from the underground pipeline. Since 1986, numerous investigations have been conducted to evaluate the extent of releases from underground fuel pipelines, the industrial wastewater line, and various USTs at the site. These investigations determined that significant amounts of free product, as well as chlorinated solvents, were present. An RI and FS summarizing the previous investigation data were completed in 1995 (Baker, 1995c) and 1996 (Baker, 1996b), respectively.
The data generated during the RI indicate that VOCs are the primary contaminants detected in the area. Specifically, chlorinated solvents were detected near LP‐20 and LP‐26. In addition, petroleum products are present east of Building LP‐22 and south of Building LP‐179. VC, 1,1‐dichloroethene (DCE), 1,2‐DCE, 1,2‐dichloroethane, TCE, and benzene were detected in the shallow aquifer (Columbia). Furthermore, VC, 1,2‐DCE, and TCE were also detected in the deep aquifer (Yorktown).
The DD (Baker, 1996d) for the LP‐20 site required that contamination at the site be treated to reduce the threat to human health and the environment. The goal of the remedial action was to treat the contaminant plume in the shallow aquifer using an AS/SVE system to prevent migration of the plume offsite and into the deep aquifer, and to reduce the contaminant concentrations to established cleanup goals. In addition, aquifer use restrictions (for both the shallow and deep aquifer) were mandated to prevent the groundwater from being used for either a potable or non‐potable (industrial water) source.
Following recommendations from the Remedial Process Optimization team, a groundwater extraction system was installed at the site to supplement the existing AS/SVE system. The enhanced system (groundwater extraction and AS/SVE systems) began operation August 2010. The groundwater that was extracted contained high concentrations of VOCs that were treated and removed, creating an overall mass reduction of VOCs in groundwater at Site 20.
High iron concentrations in groundwater caused scaling in the air stripper, which then had been taken offline to perform maintenance. Additionally, the extraction system captured residual petroleum, oil, and lubricants, from an adjacent site, which clogged the filter bags. Because of the operational issues requiring significant maintenance activities, the extraction system is no longer operating.
Based on LTM data through 2013, the AS/SVE system was turned off (but maintained in an operable condition) in 2013 while its continued/long‐term effectiveness is evaluated. During the 2017 LTM 18 groundwater samples from wells in the shallow aquifer were collected and seven samples from the wells in the deep aquifer were collected for analysis of COCs (CH2M, 2018). Since the groundwater remediation activities have been discontinued in 2013 the COC concentrations within the shallow aquifer have remained relatively stable, however, the COC concentrations remain elevated above the cleanup goals. The COC concentrations within the deep aquifer show an increasing trend when compared to previous years.
To expedite the reduction of COC concentrations within the groundwater an alternative remediation strategy, consisting of installing and pilot testing a subgrade biogeochemical reactor (SGBR), will be evaluated as a viable alternative for the remediation of VOCs at Site 20. A baseline groundwater monitoring program and bench scale testing of this remedy is anticipated to be completed in the fourth quarter of FY 2018. The pilot test for the SGBR and the performance monitoring of the system is scheduled to be initiated in FY 2019.
Site 22 - Camp Allen Storage Yard
The CASY operated from the 1940s until 1995, salvaging and processing scrap materials generated at NSN. The CASY is located between Area A and Area B of the CALF Site, as shown on Figure 2-7 below. The CASY activities have included storage and management of waste oils, used chemicals, and scrap industrial and commercial equipment. Metal smelting, various recycling activities, and miscellaneous burning also occurred at the CASY. In addition, the facility was used to store acids, paint thinners, solvents, pesticides, and transformers. A polychlorinated biphenyl (PCB) spill occurred at the CASY in 1989, when a transformer was damaged by a forklift. The PWC responded to the spill and conducted a preliminary cleanup at that time. When operations ceased in 1995, the buildings, incinerators, and rail lines were demolished.
The initial remedial action at CASY consisted of the NTCRA and offsite disposal of metals‐ and PCBcontaminated soils. A PCB removal action began in August of 1998. Additional delineation of site contaminants in 2001 identified six metals hotpots throughout the site. As an interim measure, the Navy began removal of the hotspot soils in conjunction with the ongoing PCB removal action. The hotspot and PCB‐contaminated soil removal continued through 2001, with the ultimate excavation of more than 16,000 yd3 of material. Additional soil analytical data showed that the aerial extent of metals contamination was more widespread than previously estimated. It was estimated that approximately 29,000 yd3 of soil remained at the site above the metals cleanup goals The Navy determined that the placement of a soil cover was more cost‐effective than removal of the metals‐contaminated soils, and the Team reached consensus on this course of action in March 2002.
The soil cover and the cover for the sediments in the pond were completed in June 2004. The final ROD addressing the soil and sediment at the site and encompassing the overall soil and sediment cleanup strategy for the site was signed by USEPA in September of 2004 (Baker, 2004). Quarterly site inspections continue to be completed to assess the enforcement of the LUCs. Because of the proximity of Site 22 to Site 1, groundwater beneath the sites underlying Areas A and B, as well as the Site 22 (CASY) (which is located between Areas A and B), is being managed and addressed as a single unit.
Site 23 - LP‐20 Plating Shop
Site 23, the former LP‐20 Plating Shop, is located on the west side of the building (Figure 2-8 below). In May 2005, the NSN Tier I Partnering Team agreed to conduct an interim removal action to address the site soils. The Team also agreed that the groundwater beneath Site 23 was being treated as part of Site 20. A final EE/CA was submitted in December 2006, summarizing the soil removal action (a new concrete floor to serve as a cover). The construction activities associated with the interim action were initiated in June of 2006. In September 2008, a Proposed Plan for Site 23 proposed the implementation of LUCs to effectively limit site access and to protect against human exposure to unacceptable risk in the soil at the site. The ROD for Site 23 was finalized in September 2008 (CH2MHILL, 2008), implementing LUCs as the remedy. The Remedial Design was finalized in July of 2009 to implement LUCs and maintenance actions, including periodic inspections and reporting to ensure that residential development, or any other development that is inconsistent with the specific remedial action objectives and selected remedy, will not be allowed on the site and that the concrete cover will be properly maintained until contaminant levels diminish so as to allow unrestricted use and unlimited exposure.
Quarterly site inspections are conducted to verify the implementation of the LUCs. Groundwater associated with Site 23 and Site 20 is considered one hydrogeologic unit and is currently being remediated as part of Site 20.
Due to the presence of elevated VOC concentrations in the groundwater beneath Site 23, a vapor intrusion investigation will be completed during the winter of 2019 to verify the results of EPA’s previous investigation that the groundwater does not pose an unacceptable human health risk to the workers at Site 23.
Solid Waste Management Unit 14 - Q‐50 Satellite Accumulation Area
The Q‐50 Satellite Accumulation Area (SWMU 14) is located in the northeast corner of NSN, as shown on Figure 2‐9 below. SWMU 14 consisted of a concrete storage pad surrounded by a grass‐covered field. The pad served as a 90‐day hazardous waste accumulation area where wastes generated through various waste streams were processed (sampled, identified, labeled, and packaged) before being shipped for eventual disposal. The original concrete pad for the accumulation area has since been removed. A new pad was installed west of the original location and is used for temporary storage of investigation‐derived waste materials.
In March 2008, an EE/CA was prepared for an NTCRA at SWMU 14. The objective of the NTCRA was to mitigate potential unacceptable human health risk from exposure to contaminated surface soil, subsurface soil, and subsurface debris at SWMU 14 by constructing an asphalt cover. The supporting Action Memorandum was signed April 8, 2008. Construction activities were initiated in early June 2008 and were completed in January 2009. The Focused FS was finalized in July 2009 (CH2M, 2009), followed by completion of the Proposed Plan in September 2009, recommending LUCs to prevent exposure to soil by human receptors. The ROD was signed in August 2010 to document LUCs as the selected remedy. As documented in the ROD, potential risks associated with groundwater are deemed acceptable and no action for groundwater was required; however, the LUC objectives for SWMU 14 prohibit the withdrawal of groundwater.
SWMU 14 is inspected quarterly to verify the enforcement of LUCs.