Landfill Area #1 Site Within the Governor Bacon Health Center I Ft

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION Ill 1650 Arch Street Philadelphia, Pennsylvania 19103-2029

SUBJECT: Approval of a Request for Funding for a Time-Critical Removal Action at Landfill Area #1 Site within the Governor Bacon Health Center I Ft. DuPont State Park Delaware City, New Castle County, Delaware

FROM: David Wright, Associate Director Hazardous Site Cleanup Division, Region III

TO: Mathy Stanislaus, Assistant Administrator Office of Solid Waste and Emergency Response

THRU: Lawrence Stanton, Director Office of Emergency Management

ATTN: Gilberto Irizarry, Director Program Operation and Coordination Division

ISSUE

The attached Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) Action Memorandum pertains to the Landfill Area #1 Site within the Governor Bacon Health Center I Ft. DuPont State Park located in Delaware City, New Castle County, Delaware. A removal site evaluation performed in accordance with Section 300.410 of the National Oil and Hazardous Substance Pollution Contingency Plan (NCP) has identified a threat to public health or welfare or the environment due to the uncontrolled presence and release of hazardous substances at the Site. The removal site evaluation found hazardous substances, predominantly lead, present within and migrating from the soil and sediment at the Site.

The Region has determined that this Site meets the criteria for a removal action under Section 300.415 ofthe NCP. Pursuant to Regional Delegation of Authority 14-2, funds in the amount of$ 1,919,900, of which$ 1,8J4,900, are Regional Removal Allowance Costs, have been approved to mitigate the threats posed by the Site. The attached Action Memorandum documents approval of the Removal Action necessitated by Site conditions and threats.

Attachment: Funding Request

Printed on I 00% recycled/recyclable paper with I 00% post-consumer fiber and process chlorine free. 0 Customer Service Hotline: 1-800-438-2474 AR300001 UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION III 1650 Arch Street Philadelphia, Pennsylvania 19103-2029

,l/\ 2 8 2018

SUBJECT: Request for Funding for a Time-Critical Removal Action at Landfill Area # 1 Site Located at the Governor Bacon Health Center I Fort DuPont State Park Delaware Cit , New Cast County, Delaware

FROM: Micha~e,~ - cene Coordinator Eastern Removal Response Section (3~~

TO: David Wright, Associate Director ~~ Office of Preparedness and Response (3HS30)

I. ISSUE

The purpose of this Request for Funding ("Action Memorandum") is to request funding to initiate a Time-Critical Removal Action to address a release of hazardous substances from a landfill (Landfill Area #1 Site) located at the Governor Bacon Health Center I Fort DuPont State Park. The Landfill Area# 1 Site is located along the banks of the Delaware River near Delaware City, New Castle County, Delaware. The Removal Action herein is proposed only for the Landfill Area #1 Site and not the remainder of the Governor Bacon Health Center I Fort DuPont State Park. The Removal Action addresses the Landfill Area #I Site which was the location of a fire, from which some cylinders already have been removed. A portion of the Landfill Area #1 Site is currently exposed and eroding into the Delaware River. Elevated concentrations of hazardous substances are exposed, migrating into the environment, and posing a threat to human health and environment, as discussed below.

A Removal Site Evaluation conducted by the On-Scene Coordinator (OSC) pursuant to Section 300.410 of the National Oil and Hazardous Substances Pollution Contingency Plan (NCP), 40 C.P.R. § 300.410, revealed a release and threatened release of hazardous substances, primarily metals and most notably lead, as well as low levels of polychlorinated biphenyls (PCBs), from the Landfill Area #1 Site into the environment. Based upon information obtained from the Removal Site Evaluation, and upon consideration ofthe factors in Section 300.415(b)(2) ofthe NCP, 40 C.P.R.§ 300.415(b)(2), the OSC determines that a Removal Action, pursuant to Section 104(a) ofthe Comprehensive Environmental Response, Compensation, and Liability Act, as amended (CERCLA), 42 U.S.C. § 9604(a), is appropriate and necessary to mitigate threats posed by the release and threatened release of hazardous substances from the Landfill Area #1 Site. The OSC's evaluation of the Landfill Area #1 Site conditions indicates that removal of exposed waste items (e.g., cylinders and remnants of drums containing unknown materials), removal of exposed waste materials containing high concentrations of 1

AR300002 lead, removal of debris impeding response actions, removal of eroding and contaminated soil along the bank ofthe Delaware River, consolidation and covering of remaining contaminated soil, and implementation of measures to protect users of the Park from exposed hazardous substances are the primary response actions required to mitigate the release and threatened release of hazardous substances from the Site. A Removal Action Project Ceiling of$1,919,900, ofwhich $1,814,900 are from the Regional Removal Allowance, is necessary to mitigate the threats identified in this Action Memorandum.

II. BACKGROUND AND SITE CONDITIONS

A. Site Description

Some of the information contained herein was obtained from the documents identified in paragraph A.4.a below.

1. Physical Location

The Governor Bacon Health Center I Fort DuPont State Park is generally located along the Delaware River south of Delaware City, New Castle County, Delaware. The Governor Bacon Health Center I Fort DuPont State Park includes over 380 acres and numerous buildings and features originating from military operations. The Governor Bacon Health Center I Fort DuPont State Park is generally bounded by the Delaware River to the east, the Chesapeake and Delaware (C&D) Canal and associated lands to the south, and a branch of the C&D canal to the west and north.

After the foriner military reservation (Fort DuPont) was transferred to the State of Delaware (in 1946), it was turned into the Governor Bacon Health Center. In 1992, portions were then turned into the Fort DuPont State Park. The Landfill Area #1 Site is within Fort DuPont State Park and is generally located adjacent to the Delaware River and south of the eastern terminus of Wilmington Avenue (a road within Fort DuPont State Park). The full size of the Landfill Area #1 Site is not known, but has been estimated to be approximately between 10 and 20 acres. The OSC believes, after review of all available information, that the Landfill Area #1 Site is about 12 acres in size. The eastern portion of the Landfill Area # 1 Site is located along a tidal reach of the Delaware River and is submerged by the high tide.

The Landfill Area # 1 Site is located generally east of two former gun batteries associated with Fort DuPont- Battery Ritchie and Battery Elder- as well as a former rapid fire gun emplacement. Battery Ritchie is now demolished. The guns have been removed from Battery Elder, but the structure remains. The structure of the rapid fire gun emplacement also remains. An incinerator was built near the location of former Battery Ritchie. The incinerator does not appear on available plans of Fort DuPont dating up to 1943. An aerial photograph from 1937 indicates the presence ofthe structure of Battery Ritchie, but not the incinerator. The incinerator is visible on an aerial photograph from 1946 at which time it is also apparent that Battery Ritchie had been demolished. A 1941 plan and a 1943 plan of Fort DuPont depict a "dump area" in the present location of the Landfill Area #1 Site. Aerial photographs from 193 7 and 1940 and 1946, which indicate the location of various features ofFort DuPont, also depict what appears to be disturbed ground at the location of the "dump area".

AR300003 2. Site History

Guns were emplaced at the present position of Fort DuPont during the 1860s to protect the cities of Wilmington, DE, Chester, PA, and Philadelphia, PA, from enemy invasion. Fort DuPont was completed in 1902 and became the headquarters ofthe harbor defense ofthe Delaware River and Bay and Coast Artillery Regiments.

Prior to World War I, Fort DuPont was used as a mine laying and destroying location on both land and water. During World War I the Coast Artillery Corps would spend time at Fort DuPont engaging in field training and target practice. In 1922 and until World War II the First Engineers occupied Fort DuPont. They used the facility as a proving ground for pontoon equipment. At the start of WWII, the importance ofFort DuPont increased with the transfer of the 261 st Coast Artillery of Delaware and the 122nd Coast Artillery Anti-Aircraft Battalion from New Jersey. By the end ofWWII, Fort DuPont housed over 1,000 German prisoners ofwar.

On December 31, I945, the U.S. government declared Fort DuPont to be surplus and it was decommissioned. In I946, the military reservation and all of its buildings were transferred to the State ofDelaware, who on October 28, 1948, converted Fort DuPont into the Governor Bacon Health Center.

The Governor Bacon Health Center has been occupied by several Delaware state agencies. Historically, many of these occupants have used the former military reservation and buildings for office space or storage for surplus goods, including potentially hazardous substances. The Department of Health and Social Services uses facilities at the Governor Bacon Health Center for residential treatment of patients. There is also an active sewage treatment plant, operated by New Castle County, located on approximately three (3) acres in the northeast comer of the Governor Bacon Health Center property.

In 1985, a fire occurred in the area known as Landfill Area #1. This area had reportedly been used as a dump by the U.S. Army and possibly subsequently by the State of Delaware. The cause of the fire is not known. Cylinders reportedly containing bromotrifluoromethane and ethylene oxide were removed from the burned area under direction ofthe State of Delaware (the OSC was unable to find records specific to this activity).

In 1992, the Fort DuPont State Park was dedicated and created from portions of the Governor Bacon Health Center property.

3. Site Characteristics

The Landfill Area #1 Site is located within Fort DuPont State Park and along a tidal reach of the Delaware River. The Landfill Area# I Site appears to have been originally used for the purpose of discarding/dumping materials in an area distant from the center of operations of the former Fort DuPont. A portion of the Landfill Area #1 Site is presently covered by small trees and woodland; the remainder is covered by tall grasses or exposed within the tidal zone oft~e Delaware River. The degree to which the discarded materials in the Landfill Area #1 Site were originally or subsequently covered or capped is not known (only that an area which caught fire in 1985 was reportedly covered by about 1 foot of soil according to available summary information). The eastern limits of the Landfill Area #1 Site are submerged by the high tide of the Delaware River. A portion of the Landfill Area #I 3

AR300004 Site has been eroded away by the Delaware River; this erosion has exposed the materials discarded in the Landfill Area #1 Site. These materials are mixed within the surficial materials (sand/soil/ mud/sediment) which comprise the bank of the Delaware River and are exposed and accessible (more so at the low tide). The discarded materials include debris likely associated with demolition (e.g., broken bricks or tiles), metal objects (e.g., pipes, equipment parts, hinges, etc.) and other objects associated with military operations (e.g., military uniform buttons, pottery with insignia, pieces of small arms ammunition, etc.). Additionally, bits of melted glass, various forms of metallic lead, and other items can be observed within a matrix which includes an ash or gritty material in some locations. The remains of two drums and a glob of white material (unknown content) similar to paint are also exposed on the shoreline ofthe Delaware River.

Several walking trails and habitat areas have been created within Fort DuPont State Park. A trail directs people to and through the Landfill Area # 1 Site. Signs discourage users of the Park from removing objects and items. Tall grasses and woodland provide the only barrier between the trail and the exposed landfill materials.

4. Removal Site Evaluation

a. Review of Available Documents

The EPA OSC considered numerous documents as part of the removal site evaluation of Landfill Area # 1. Among the documents are: 1) a Field Trip Report for Governor Bacon Site prepared for EPA by the NUS Corporation in 1986; 2) Fort DuPont Delaware: An Architectural Survey and Evaluation, prepared for the Delaware Department of Natural Resources and Environmental Control (DNREC) in 1994 ("1994 architectural survey':); 3) two geophysical survey reports prepared in 1992 for the U.S. Army Corps of Engineers and in 2001 for DNREC; 4) a 2001 Archeological Survey and Monitoring report prepared for DNREC; 5) a 2003 Site Inspection Governor Bacon Health Center/Fort DuPont State Park prepared by DNREC; 6) a 1987 Site Analysis prepared by EPA's Environmental Monitoring Systems Laboratory; and, 7) several figures and aerial photographs contained in the documents listed above or available for view from other publicly available web-based sources. Documents 1, 3 and 4 listed above are either summarized within or found attached to document 5 listed above.

Based upon a review of available information, including aerial photographs from 1937, 1940 and 1946 and plans ofFort DuPont from 1941 and 1943, Landfill Area #1 may be associated with a "dump area" depicted on plans of Fort DuPont. Landfill Area #1 is also proximal to the remains of what is identified in the 1994 architectural survey as a former incinerator. The former incinerator is identified in the 1994 architectural survey as existing prior to 1941. The incinerator structure is not visible on the 1937 aerial photograph. It is, however, visible on the 1946 aerial photograph. The remains of the former incinerator are still present and include ashy gritty material within its foundations.

Aerial photographs from 1937, 1940 and 1946 depict disturbed ground (suggested by a lightly colored contrasting area in the vegetative cover which is of darker imaging in the photographs) along the Delaware River. These aerial photographs also depict roadways leading to the area of disturbed ground from the main area of Fort DuPont suggesting a relationship between the Fort and the disturbed 4

AR300005 ground. This area is also labeled as "dump area" on plans ofFort DuPont dating from 1941 and 194 3. The area of disturbed ground and a new roadway are also observable on a 1959 aerial photograph. Casual and current observation of this disturbed ground area indicate the presence of debris associated with demolition (e.g., broken bricks, tiles, slate, concrete, etc.), metal objects (e.g., pipes, equipment parts, hinges, tools, etc.), objects associated with military operations (e.g., military unifonn buttons, pottery with insignia, pieces of small arms ammunition, etc.), and objects associated with human occupation ofthe Fort (e.g., bottles, tools, keys, screws, small parts, etc.). Additionally, various forms oflead are found. Collectively, this non-native material is considered "debris" within the context of the environmental sampling activities discussed below and was not specifically sampled. The OSC believes that the disturbed ground ("dump area") is a portion of present day Landfill Area #1 Site.

The 1994 and 2001 architectural survey documents indicate that dikes were constructed along the eastern boundary of the Fort property to allow for draining of the wetlands along the River's edge (likely between 1870 and 1890). A 1915 figure of Fort DuPont indicates that construction of Fort DuPont included filling activities in an area behind a "tide bank" constructed between the Fmi's structures and the Delaware River. Plans ofFort DuPont beginning in 1901 also depict a straight line feature as a timber bulkhead, line of sheetpiling or old retaining bank. A 1941 plan ofF ort DuPont also indicates that a timber bulkhead separates the area of the Fort from the Delaware River. Information also indicates that dredge materials may have been used to fill the wetlands alongside the Fort. Dredge material from the River was likely placed along the edge of the Fort in the early 1900s as indicated in the archeological reports. Collectively, this information suggests the likely presence of "made land" or fill material in the area of the Fort. The straight line feature is easily observed on aerial photographs from 1937 and 1940.

Disturbed ground is visible on the River side of the timber bulkhead in the 193 7, 1940 and 1946 aerial photographs. This area of disturbed ground is most likely the area labeled as "dump area" on a 1941 plan and a 1943 plan ofthe Fort. This area of disturbed ground labeled as "dump area" was the primary area field assessed and sampled by EPA during the removal site evaluation.

b. Summary of Previous Sampling and Evaluation of the Landfill Area #1 Site

Following a 1985 fire in Landfill Area #1, a survey for ordnance and/or explosives was conducted in 1986. It was determined that the area contains only buried metallic debris.

In October 1992, a preliminary assessment was performed at Landfill Area # 1 by a contractor under contract to the United States Army Corps of Engineers (USACE). The assessment included analysis of ground water, near-surface soil, and sediment in the vicinity of Landfill Area #1, as well as a survey for the presence of unexploded ordnance in the area.

The 1992 survey for unexploded ordnance identified high magnetic readings in the following areas: on a cut path on the north side of the investigation area between the Delaware River and incinerator building, along the bank of the Delaware River, and within a 100 to 200-foot range south of the incinerator. The survey team could not determine whether the readings were due to scrap metal or unexploded ordnance.

AR300006 Sampling and analysis of environmental media at the Landfill Area #1 Site in 1992 indicate concentrations of lead and cadmium in the soil above a range common for soils in the area. Additionally, low levels of semi-volatile organic compounds (polycyclic aromatic hydrocarbons (PAHs)), polychlorinated biphenyls (PCBs), and petroleum hydrocarbons were found in the soil. Ground water sampling results showed very low concentrations of organic and inorganic contaminants. Low concentrations of P AHs, PCBs, and petroleum hydrocarbons were detected in sediment samples taken along the Delaware River. In 1992, sediment samples were reported to exceed comparative sediment standards for arsenic, cadmium, chromium, mercury, barium, copper, lead, and zinc. The USACE contractor recommended further delineation of metals contamination in sediments along the river in order to determine the potential for threats to human and environmental health and acknowledged that, while no explosive ordnance was detected during the investigation, the potential for future exposure exists.

In 2000, in advance of a sampling event, a geophysical survey was performed along the walking trails in and around Landfill Area# 1. The results indicated signatures indicative of buried metallic material. A pathway leading from the area of the incinerator to a large rampart had the largest potential for buried metal objects ·based upon the geophysical anomalies. In 2001, an additional geophysical survey was completed along with shallow excavation of numerous identified anomalies. The anomalies were predominantly related to wire, nails, hinges, pipes, etc. No ordnance or explosive or related material was identified.

DNREC concluded a sampling assessment in 2001, which included Landfill Area #1 as well as other areas, and prepared a Site Inspection Report in 2003. Samples of soil and ground water from locations within or near Landfill Area #1 were collected. Concentrations of certain metals (notably lead) were elevated in the soil above concentrations reasonably anticipated to represent soil background concentrations. Most notable was the detection of lead in soils above 1000 mg/kg in the area closest to the location of the incinerator and the "dump area" identified in a diagram of Fort DuPont. Additionally, a sample of soil from this area was subject to the Toxicity Characteristic Leaching Procedure (TCLP) test and indicated levels of leachable lead above standards for hazardous waste disposal.

c. Summary of Sampling and Analyses Conducted during the Removal Site Evaluation

Based upon available information and the request of DNREC, the OSC initiated a removal site evaluation in accordance with Section 300.410 of the NCP. The removal site evaluation progressed through three main events- December 2011, July 2012 and December 2012.

December 2011 removal site evaluation

A sampling plan was prepared in October 2011 and approved by the OSC. The assessment team initiated the field sampling assessment on December 5, ·2011. The sampling activities included two main components: 1) excavation of test pits accompanied by screening and sampling of the subsurface materials encountered and 2) sampling of material ("sediment") at the ground surface. An XRF device was used to screen various media and items for element content. The removal site

AR300007 evaluation was focused on that portion of the Landfill Area # 1 Site found to be eroding into the Delaware River.

Sixteen test pits were excavated in a line parallel to the River and approximately positioned mid-way between the high and low tide lines. These "tidal area" test pits were dug using a mini excavator while UXO technicians observed the activities. A total of 16 samples were collected from a total of 12 of the tidal test pits.

Seven test pits were excavated in a line parallel to the River, but above the high tide line, within the area thought to include the disturbed ground area seen on aerial photographs. These "upland area" test pits were dug using a mini-excavator after tall grasses were removed and while UXO technicians observed the activities. A total of 5 samples were collected from a total of 5 of the upland area test pits.

Twenty-two samples of surface material ("sediment") were also collected in a grid pattern throughout the area characterized by debris and within the tidal zone of the River. Additionally, samples of surface material ("sediment") were collected immediately downgradient of two locations at which oily material was observed discharging during low tide. Finally, two samples of water encountered within two of the tidal area test pits were collected. The water was typically encountered well within 1 foot of the land surface and can be seen discharging into the Delaware River at numerous locations. All collected samples were analyzed for metals. A select number of samples were also analyzed for organic parameters.

Oil was observed discharging from the Landfill Area # 1 Site into the Delaware River at at least two locations. The. amount of oil was not significant and any sheen dissipated within inches of the shoreline. It is unknown if the oil originated from the landfill or came ashore and is now located within the landfill area.

Objects related to the military operations at the Landfill Area #1 Site were identified throughout the assessed area. These objects included small ammunition parts, uniform insignia and uniform buttons, and pieces of stamped pottery and silverware. Objects likely related to the demolition or dismantling of buildings and the operations therein or simply related to occupation and operations at the Fort and the Landfill Area #1 Site were identified throughout the assessed area and included bottles, equipment (including electrical) parts, hinges, bricks, tiles, tools, keys, etc.

The OSC observed pieces of metallic lead throughout the area. The lead was found as several types of shaped (cast) forms, as casing around electrical wire, as melted blobs, and as small fragments. A small arms shell casing was found covered by lead. At least one of these lead pieces was screened with an XRF to verify its lead content (over 90% ). It appears to the OSC that the material may have resulted from 1) an operation which produced lead in various forms, 2) the demolition of structures that contained electrical wiring likely intended to be protected from exposure to water, 3) lead subjected to heat, and 4) an operation which caused lead to spatter and cool.

Analytical results of the sampling activities indicated concentrations of lead well above any reasonable concentration attributable to the natural environment. Lead was detected at concentrations up to 36,800 mg/kg. Sampling activities also identified other elements (e.g., arsenic) which may exist

AR300008 above typical background concentrations. Arsenic was detected at concentrations up to 115 mg/kg. Other metals may also exist above reasonable background concentrations.

The analytical results of the tidal area test pits, comprising predominantly orangey or dark gray colored fill-type material, indicated lead concentr(}.tions up to 15,000 mg/kg in tidal area Test Pit 6.

The analytical results of the upland area test pits, comprising predominantly dark colored fill type material, indicated lead concentrations up to 36,800 mg/kg in Test Pit U7.

The analytical results ofthe sampling of surface material (sediment) amongst the debris and inundated by the tide also indicated lead contamination. A sample collected near a portion of a buried drum exhibited the highest lead concentration in surface sediment (28,300 mg/kg).

The two samples of water collected from tidal area test pits exhibited lead concentrations of 97 and 157 ug/L. The lead concentration in the fill material within these two test pits was relatively low at 486 mg/kg and 22.5 mg/kg, respectively (since the samples were collected from locations noted for oil and not for lead). As such, it is possible that the lead concentration in the shallow water could be higher in other areas of the Landfill Area # 1 Site.·

The two samples of water collected from the tidal area test pits contained polychlorinated biphenyls (PCBs) detected via congener analysis. The analytical results indicate low levels ofPCBs (31.4 and 36.7 ng/L). PCBs (analyzed as aroclor) were not detected in soil or sediment samples. The two test pits from which water samples were collected also exhibited oily sheen.

July 2012 removal site evaluation

The October 2011 sampling plan was amended in May 2012 to guide additional sampling activity. Additional removal site evaluation activity was conducted in July 2012. The objectives of the July 2012 removal site evaluation activities focused on evaluating the potential migration of lead contamination from the Landfill Area # 1 Site into the environment and the levels of lead in soils within the area routinely accessed by users of Fort DuPont State Park.

Surface material (sediment) samples were collected from 5 locations on the shoreline of the Delaware River in the area designated as the Landfill Area # 1 Site. The analytical results of the sampling of sediment amongst the debris and inundated by the tide indicated lead concentrations ranging between 1140 and 55,200 mg/kg. A sample collected near a portion of a buried drum exhibited the highest lead concentration in surface sediment (55,200 mg/kg). A sample collected immediately downgradient of an area covered by visible pieces of lead exhibited the second highest lead concentration in surface sediment (20,500 mg/kg).

Surface soil samples were collected from 3 locations on or near the path that traverses the Landfill Area #1 Site. The analytical results of the sampling indicated lead concentrations between 647 and 6,600. mg/kg.

A sample was also collected from the material currently located in the base of the incinerator. The analytiCal result of this sample indicated lead at a concentration of2,440 mg/kg. 8

AR300009 Several ofthe samples were subjected to TCLP analysis to determine ifthe matrix would be characterized as a hazardous waste. The analytical results showed that lead leached from the matrix at levels between 0.8 and 58.2 mg/1 indicating that the contaminated materials could be considered a hazardous waste under the Resource Conservation and Recovery Act regulations, 40 C.F .R. Section 261.24.

Samples of water were also collected from 3 locations. Two samples of water from the Delaware River were collected from the area where oil was seen seeping from the shoreline in December 2011. These samples indicated levels oflead at concentrations of 15.9 and 19.5 ug/L. A sample of water from the Delaware River was also collected near the location of pieces of visible lead on the shoreline. This sample exhibited lead at a concentration of 53.5 ug/L. A sample of water from the Delaware River was also collected near the location of exposed, but partially buried, drums on the shoreline. This sample had lead at a concentration of 134 ug!L.

December 2012 removal site evaluation

In December 2012, the OSC directed activity intended to define the limits ofthe Landfill Area #1 Site. The activity occurred after a significant storm event ("Sandy") affected the shoreline in October 2012. The storm clearly removed (eroded) and/or covered material from the shoreline as some objects visible in July 2012 were no longer present and other objects had been uncovered or further uncovered. Many of the EPA's location stakes placed in December 2011 were still present, but mostly exposed. Notable changes on the shoreline include 1) complete removal of 1 drum from the area 2) nearly complete exposure of a second drum, 3) exposure of a mass of soft white material similar to paint.

Using a small excavator, pits were dug in and around the presumed limits of the Landfill Area #1 Site. The initial limits of the Landfill Area #1 Site were estimated based upon aerial imagery from 1937 and 1940. Additionally, the location ofthe Landfill Area #1 Site was estimated based upon maps of Fort DuPont from 1941 and 1943; the OSC estimated the position ofthe "dump area" depicted on plans of the Fort relating to the present day position of the remains of Battery Elder. The limits were predominantly located in an area of phragmites vegetation.

Some of the excavated areas exhibited materials including large pieces of metallic items (e.g., pipes, or stakes for barbed wire), numerous bottles, pieces of pottery, and layers of materials similar to that existing on the shoreline. Other excavated areas (located inland of the shoreline) contained materials inclusive of plastic suggestive of a newer source. Most excavated areas contained rubble (broken bricks, concrete, etc.) suggestive of demolition. In summary, the OSC believes that the area indicated on the 1937 and 1940 imagery contains large pieces of metal (e.g., pipes and similar items), numerous bottles, pieces of pottery, electrical equipment, insulators, and a fairly ubiquitous layer of ashy or gritty material between approximately 12 and 30 inches below ground surface. Areas beyond the above-indicated area generally included plastic items (e.g., toys or sheeting) possibly suggestive of a more recent disposal event or from a newer or different source.

The OSC believes that the position of the timber bulkhead (identified on maps of Fort DuPont) within the Landfill Area #1 Site may have been located during the removal site evaluation. Vertically 9

AR300010 positioned lumber was found where the bulkhead would likely be located. Materials on either side of the bulkhead were quite different. On the River side the OSC found large amounts of large metallic items (e.g., pipes), bottles, and pieces of pottery along with elevated levels oflead. On the inland side of the bulkhead, far less foreign material was noted and the soils were different in appearance.

Based upon the totality of information, the OSC believes that the Landfill Area # 1 Site consists of two types of disposal. First, an area of "older disposal" inclusive of metal objects (including larger objects such as pipes and very small items such as keys), bottles, pieces of pottery, pieces of ammunition, military items, bricks, etc. and elevated concentrations of lead about 5 acres in size. This area of objects and elevated levels of lead is found at the surface along an approximate 600 feet of shoreline of the Delaware River. The thickness of the disposal above the water table ranges from approximately 30 inches in the vicinity of the bulkhead to a few inches at the line ofthe low tide. However, items are also visible under the waters of the Delaware River.

A slightly different area of disposal exists along with and predominantly inland of the above and includes larger pieces of rubble (concrete with rebar), metallic items such as bedsprings, bricks, and pieces of plastic (sheeting, toys, bottles, etc.). The OSC believes that elevated lead concentrations found in some of this different and more inland disposal may be related to a white coating (likely paint) found upon pieces of wood and/or the incinerator.

Two heavily rusted cylinders of unknown contents were found east of the incinerator. The OSC believes the cylinders contain material for the suppression of fire based upon the location of a handle associated with the valve. Additionally, an amorphous mass of white material (similar to paint) was found on the shoreline in the vicinity of the drum.

d. Quantities and Types of Hazardous Substances

Lead is a hazardous substance within the meaning of CERCLA since it is listed at 40 CFR 302.4. Sampling activities at the Landfill Area #1 Site detected lead at concentrations up to 55,200 mg/kg within sediments adjacent to the Delaware River. Sampling activities at the Site also identified other hazardous substances (e.g., arsenic) in the sediments along the River. Arsenic was detected at 115 mg/kg. Lead and arsenic are also naturally occurring elements. However, the concentrations of lead and arsenic and other hazardous substances at the Landfill Area #1 Site are found at concentrations well above typical background concentrations. Areas of the Landfill Area #1 Site exhibiting potentially elevated concentrations of hazardous substances other than lead also exhibited elevated concentrations of lead. As such, the element lead may be used as a good indicator of the possible extent of contamination. The focus of the removal site evaluation conducted thus far was the eroding eastern limits of the Landfill Area #1 Site along the Delaware River.

Polychlorinated biphenyls (PCBs) are hazardous substances and are located at the Site. The analytical results of samples collected from the landfill Area #1 Site indicate PCBs at low concentrations within the water and limited soil encountered in a limited number test pits dug at the Landfill Area #1 Site. However, only a limited number of samples (2) were collected. The area contaminated by PCBs is not quantified. ·

AR300011 Approximately 630 feet x 40 feet (25,200 square feet) of soil/sediment in the tidal area is likely contaminated by hazardous substances and either exposed at the surface or eroding into the Delaware River. The depth of the hazardous substance contamination is likely to be shallow (e.g., measured as just a few inches) near the low tide line and increasing to nearly three feet thick atop the water table near the high tide line. An unknown amount of the contaminated material is below the water table.

The OSC believes that the area of the Landfill Area #1 Site containing buried objects similar to those observed on the shoreline along with the elevated levels of lead is approximately 12 acres in size and about an average of2.5 feet thick atop the water table representing approximately 12,000 tons of material. However, there is a great deal of variability in the disposal (e.g., large blocks of concrete alongside pieces of lead alongside contaminated soil). Additionally, soil has been placed atop some of the disposed materials.

The presence of additional hazardous substances is unknown, but the presence of additional items such as the cylinders removed from the landfill fire area in 1985 must be considered. Two cylinders were found near the surface of the Landfill Area #1 Site during the removal site evaluation. B. Other Actions to Date

In 1985, a fire occurred in the area known as Landfill Area #1. Fourteen gas cylinders were removed as a result of the fire; six contained ethylene oxide, and eight contained bromotrifluoromethane. One foot of fill was reportedly added to the burned area following the fire. Beyond the sampling events noted above, there are no other known response actions involving the Landfill Area #I Site.

C. National Priorities List Status

Neither the Landfill Area #1 Site nor Governor Bacon Health Center I Fort DuPont State Park are proposed for inclusion on the CERCLA National Priorities List (NPL). The OSC has forwarded and will continue to forward analytical and other information to EPA Site Assessment personnel for further consideration. Removal actions proposed herein will not impede any future remedial actions, should they occur.

D. State and Local Authorities' Role

The Landfill Area #1 Site and other areas of Governor Bacon Health Center I Fort DuPont State Park have been evaluated and/or subject to various response actions by DNREC. DNREC conducted and directed sampling and analysis of the soil, ground water, and surface water at the Landfill Area #I Site in 2000 and/or 2001. Additionally, DNREC directed the removal of cylinders (bromotrifluoromethane and ethylene oxide) from a fire location in the Landfill Area #1 Site in 1985. DNREC also directed and conducted removal of hazardous substances in drums and soils from several other locations at the Governor Bacon Health Center I Fort DuPont State Park unrelated to the Landfill Area # 1Site.

The OSC coordinated activities associated with the assessment and evaluation of the Landfill Area #1 Site with DNREC. EPA and DNREC concur that timely action is needed at the Landfill Area 11

AR300012 # 1 Site. DNREC has indicated that EPA assistance is necessary to facilitate actions at the Landfill Area # 1Site. The State of Delaware is the owner of the Landfill Area# 1 Site and is requesting EPA assistance, minimally, to coordinate with the Army (previous owner of the Site) to facilitate response actions. DNREC has and will continue to offer technical assistance. Local authorities have no current role with evaluating or responding to the release of hazardous substances at the Landfill Area #1 Site and no role is anticipated.

III. THREATS TO PUBLIC HEALTH OR WELFARE OR THE ENVIRONMENT

The Landfill Area #1 Site includes elevated levels of hazardous substances exposed at the surface within a public park located along a tidal reach of the Delaware River. Additional hazardous substances could be exposed as erosion exposes hazardous substances now located in the subsurface (e.g., within samples collected from test pits). A storm event in October 2012 already has uncovered m~terials, inclusive of a mass of unknown amorphous white material and a drum, not seen in July 2012. This storm event removed at least one drum containing unknown materials. Trails in the park direct its users to and through the Landfill Area #1 Site. Tall grasses exist between the trail and the exposed materials eroding from the Landfill Area #1 Site (e.g., objects related to the military operations at Fort DuPont including small ammunition parts, uniform insignia and uniform buttons, pieces of stamped pottery and silverware in addition to the hazardous substances) and represent the barrier between exposed materials and possible human receptors. These exposed materials create an attraction and users of Fort DuPont State Park are known to collect these items despite signage discouraging such activity. The OSC believes that direct contact threats posed by the Landfill Area# 1 Site to human health are present. Access to the Landfill Area #1 Site is unrestricted. Although the Landfill Area #1 Site may be utilized for recreational purposes (e.g., bird watching, walking), these short-term potential exposures are not expected to currently result in significant threats posed by incidental ingestion of contaminated soil. A potential threat is posed to human receptors that may use the Landfill Area # 1 Site in the future for recreational or other purposes since the concentrations of hazardous substances, notably lead, in the surface soil or sediment is high. Potential threat to humans is posed by incidental ingestion of contaminated soil in the future and present exposure to unknown materials (e.g., cylinders or wastes exposed in the future as the landfill continues to erode).

The OSC coordinated with DNREC and the EPA Biological Technical Assistance Group (BTAG) regarding potential threats posed to ecological receptors and then subsequently and potentially to human receptors through ingestion of aquatic organisms (i.e., food chain). Landfill Area #1 Site sampling and analytical results indicate that the environment and habitat of ecological receptors (River sediment) is impacted by hazardous substances at levels significantly higher than background levels and benchmark risk levels established by the National Oceanic and Atmospheric Administration (NOAA) and EPA's BTAG. The analytical results suggest that the sediment at the Landfill Area #1 Site is probably toxic to aquatic receptors. The removal site evaluation confirmed that lead is releasing from the Landfill Area #1 Site into the Delaware River. The removal site evaluation also indicated that PCBs may release from the Landfill Area #1 Site into the Delaware River.

Promulgated Federal criteria for sediment contamination levels intended for the protection of aquatic organisms do not exist. To determine if threats are posed to ecological receptors, EPA and NOAA instead rely upon a comparison between site-specific contaminant levels and screening 12

AR300013 guideline levels developed from contaminant- and organism-specific toxicity testing. The screening guideline levels identify benchmark sediment contaminant levels at which toxicity testing has established a likelihood of adverse biological effects to exposed aquatic organisms. These guidelines, published by NOAA and/or EPA in the form of screening reference tables, indicate that sediment concentrations of lead above about 250 mg/kg in freshwater sediment could likely cause adverse biological effects to exposed aquatic organisms (e.g., NOAA Screening Quick Reference Table for Inorganics in Solids (NOAA AR&R Report 08-L (2008)). The concentration of lead in the sediment at the Landfill Area #I Site is significantly higher than this benchmark level by two orders of magnitude. Thus, EPA considers that the sediment at the Landfill Area #I Site could pose an adverse biological risk to exposed ecological receptors such as fish, shellfish, and/or crustaceans which have been observed by the OSC at the Landfill Area #I Site.

The removal site evaluation also demonstrated that elevated levels of lead within the soil/sediment at the Landfill Area #I Site are further releasing into the surface water environment. The concentrations of lead found within the surface water samples are well above water quality standards;

Additionally, DNREC evaluated the analytical data from the Landfill Area #I Site. DNREC found that numerous metals, e.g., lead, copper, and zinc, often exceeded concentrations potentially toxic to aquatic receptors. DNREC concludeci that most sediment samples at the Landfill Area #I Site could likely be toxic to aquatic receptors when compared to other sediment samples collected throughout the Delaware estuary.

Landfill Area #I Site sampling and analytical results indicate that the environment and habitat of ecological receptors (sediment) may also be threatened by PCBs (as detected in the surface water of two test pits in the tidal area). The area of the test pits is submerged at high tide. This detection of PCBs indicates that PCBs are able to migrate into the surface water environment, i.e., Delaware River, at the Landfill Area # 1 Site. The source of the PCBs contamination is not kn9wn. The Delaware River contains fish that are removed from the River for consumption purposes as observed by the OSC and as documented by others. PCBs can bioaccumulate in exposed organisms and currently result in elevated levels of PCBs in Delaware River fish tissue. Although detected at low levels, the concentration of PCBs in the waters accumulated in the 2 sampled test pits at the Landfill Area #I Site (31.4 and 36.7 ng/L ), exceed criteria established for the protection of the Delaware River (i.e., water quality criteria protective of aquatic life - 14 ng/L) and, according to DNREC, are higher than ambient PCBs concentrations measured by DNREC in this part of the Delaware estuary (2 to 6 ng/L ). The State of Delaware (DNREC Division ofFish and Wildlife) has posted a fish consumption advisory for the Delaware River in the area of the Landfill Area #1 Site due, in part, to PCBs contamination in fish.

Hazardous substances released at and from the Landfill Area #1 Site may bioaccumulate in the food chain. Bioaccumulation poses a threat to migratory birds and to human receptors ingesting aquatic organisms such as fish, shellfish, and/or crustaceans in the contaminated environment. Actions to prevent further release of hazardous substances from the Landfill Area #1 Site will ensure that risks to the food chain posed by bioaccumulation are reduced. PCBs now present in the environment of the Delaware River have entered the food chain; humans (fishermen and others) are a part of the Delaware River food chain through consumption of fish. PCBs, which are a probable human carcinogen, tend to accumulate in the fatty tissue of exposed organisms. Animals and the food chain are potentially exposed to PCBs thereby posing a threat to human populations. The Delaware River Basin 13

AR300014 Commission has established Water Quality Standards to protect human health and environment; these standards include limitations for PCBs in the water. Additionally, and based upon PCBs within fish tissue, a fish consumption advisory is posted for the area of the Delaware River alongside the Landfill Area #1 Site.

In addition to the observed and analyzed hazardous substances, the potential also exists for other hazardous substances to erode from the Landfill Area # 1 Site and expose human receptors or enter into the Delaware River ecosystem. Previously and after a fire caused by unknown reasons, cylinders containing hazardous materials or hazardous substances have been removed from the Landfill Area #1 Site. The OSC found 2 additional unknown cylinders at the landfill Area #1 Site in December 2012. Additionally, thetypes of materials disposed into the Landfill Area #1 Site are not fully known and the potential for unknown and potentially hazardous substances to become exposed in the Landfill Area #!Site is possible.

Section 300.415 ofthe NCP, 40 C.P.R.§ 300.415, identifies factors to be considered in determining the appropriateness of a removal action. Paragraphs (b) (2) (i), (ii), (v), (vii), and (viii) apply to the need for response at the Landfill Area # 1 Site as follows.

§ 300.415 (b)(2)(i) "Actual or potential exposure to nearby human populations, animals, or the food chain from hazardous substances or pollutants or contaminants"

Unknown waste materials, including some drummed waste materials, have been exposed upon the shoreline of the Delaware River. Media near these unknown wastes demonstrate high levels of hazardous substances. Some of these materials have subsequently been washed away by storm events. Waste materials consisting of lead casts, pieces, etc. are also present on the shoreline. Cylinders containing unknown materials are also located near the walking trails. Access to the shoreline by human receptors is discouraged, but possible and occurring.

The contaminated soil and sediment is potential habitat for a variety of ecological receptors, such as fish, shellfish and crustaceans. The concentrations ·of hazardous substances detected in the sediment may result in adverse biological effects to exposed ecological receptors such as fish, shellfish, and crustaceans, based upon scientific studies considered by EPA and NOAA when developing the "Screening Guideline" levels discussed above.

Lead is a hazardous substance and is located at the Landfill Area #1 Site. Exposure to lead by aquatic organisms may result in increased concentrations of lead in the blood of exposed organisms and may affect the growth, reproduction, and behavior of aquatic species. Lead may also bioaccumulate in exposed organisms which can result in lead poisoning and entrance to the food chain. Lead within exposed organisms may pose a potential threat via the food chain to migratory birds and potentially to human receptors ingesting the aquatic organisms. The OSC has observed crustaceans in the sediment at the Landfill Area #1 Site, waterfowl (herons and geese) near the Landfill Area #1 Site, an eagle, and fish which rely on the Landfill Area #1Site area for habitat. The OSC has also observed fishermen in boats off the banks of the Landfill Area# 1Site.

AR300015 In the absence of cleanup activities, the Landfill Area #1 Site also poses a potential direct contact threat to human receptors. Future users of the Landfill Area # 1Site may also be exposed if the Landfill Area #1 Site use is converted. Incidental ingestion oflead in the soil or sediment at the Landfill Area #1 Site may result in increased blood lead levels. Lead is known to adversely affect the central nervous system.

Polychlorinated biphenyls (PCBs) are hazardous substances and are located at the landfill Area # 1 Site. The analytical results of samples collected from the Landfill Area # 1 Site indicate that PCBs are likely entering the Delaware River. DNREC's Division ofFish and Wildlife has posted a fish consumption advisory applicable to the Delaware River alongside the Landfill Area #1 Site recommending limited ingestion of fish due to PCBs contamination. The Delaware River contains fish that are removed from the River for consumption purposes as observed by the OSC and as documented by others. PCBs can bioaccumulate in exposed organisms and within the food chain. PCBs now present in the environment of the Delaware River have entered the food chain; humans (fishermen and others) are a part of the Delaware River food chain through consumption of fish. PCBs, which are a probable human carcinogen, tend to accumulate in the fatty tissue of exposed organisms.

§ 300.415 (b)(2)(ii) "Actual or potential contamination of drinking water supplies or sensitive ecosystems"

Contaminated sediments have been identified in tidal areas which are habitat to a wide variety of aquatic and terrestrial organisms including migratory birds and fish, despite the industrialization of much of the surrounding area. Tidally exposed contaminated sediment provides ground for feeding birds such as herons. The submerged sediment provides habitat for bottom feeding fishes and crustaceans. Because suitable habitat may be scarce in this developed area, available habitat is widely utilized. The contamination of the sediment in the available habitat makes it easy for hazardous substances to enter into the food chain.

§ 300.415 (b)(2)(v) "Weather conditions that may cause hazardous substances to migrate or be released"

Flooding events or storm events, combined with other factors (such as large amounts of debris) that·may exacerbate the potential for erosion of the River bank, will facilitate the release of hazardous substances from the Landfill Area #1 Site into the Delaware River. Erosion of the sediment from the Landfill Area #1 Site will continue to expose additional hazardous substances and other unknown materials within the Landfill Area #1 Site. A storm in October 2012 significantly altered the material contents upon the shoreline at the Landfill Area #1 Site. At least one drum of unknown material was washed away; sediment near this drum contained the highest level of lead contamination observed at the Landfill Area # 1 Site. At least one additional drum and an amorphous mass of unknown white material were exposed by the October 2012 storm.

§ 300.415 (b)(2)(vii) "The availability of other appropriate federal or state response mechanisms to respond to the release"

Both the federal and state governments have mechanisms to respond to a release of hazardous substances at the Landfill Area # 1 Site. At this time, discussions between EPA, DNREC and the 15

AR300016 United States have not resulted in identification of the mechanism able to respond to the situation in a timely manner. The OSC will continue to coordinate with and/or inform the State and the U.S. Army Corps of Engineers.

§ 300.415 (b)(2)(viii) "Other situations or factors that may pose threats to public health or welfare of the United States or the environment"

The Landfill Area #1 Site is located in a tidal reach of the Delaware River. The combination of tide surges and storm events may act to continue to erode the bank of the Landfill Area #1 Site and deposit or erode sediment from the area of the Landfill Area #1 Site. An erosional event in October 2012 caused large amounts of material observed on the shoreline in July 2012 to migrate (presumably into the River). An additional erosional event may cause the migration of contaminated soil directly into the environtnent of the Delaware River, increasing the potential for hazardous substance exposure to aquatic organisms, increasing the potential for unknown items to erode from the Landfill Area # 1 Site, and increasing a public health threat posed by ingestion of organisms from the River.

IV. ENDANGERMENT DETERMINATION

Actual or threatened releases of hazardous substances from the Landfill Area # 1 Site, if not addressed by implementing the response actions outlined in this funding request, may present an imminent and substantial endangerment to the public health, welfare, or the environment.

V. PROPOSED ACTIONS AND COSTS

The actions proposed in this Funding Request are intended to remove high concentrations of hazardous substances and minimize the further migration of hazardous substances, notably lead, into the environment. In addition to posing a threat to human receptors via incidental ingestion of surface soil, hazardous substances which exist immediately adjacent to the Delaware River and are releasing into the River, pose a potential threat to aquatic receptors. The Action will not result in the complete removal of hazardous substances from the Site. Instead, the response action focuses on high concentrations of hazardous substances, the erosion of contaminated materials, and the stabilization of hazardous substances which may further migrate into the environment. The OSC will coordinate with DNREC regarding subsequent actions or post-removal site controls to ensure protection of human health and environment.

A. Proposed Actions

1. Mobilize personnel and equipment.

2. Install facilities and implement temporary measures (e.g., remove vegetation, install roads, install fencing) to improve, facilitate, and control access to and provide security for the Landfill Area # 1 Site to facilitate efficient performance of the response action and minimize exposure of workers to hazardous substances during the response action.

AR300017 3. Prepare and maintain temporary storage for hazardous substances handled during the response action.

4. Install temporary Erosion & Sedimentation (E&S) Control facilities, such as construction entrance, siltation fencing, swales, temporary vegetation, and/or settling ponds, to minimize release of hazardous substances from the Landfill Area # 1 Site, including into the Delaware River during the response action.

5. Install temporary isolation barriers between the Landfill Area #1 Site and the Delaware River to minimize transport of hazardous substances from the Landfill Area #1 Site into the Delaware River during the response action or otherwise conduct activity to prevent such transport.

6. Remove oversized or excessive debris (e.g., pipes, concrete, metal, and brick) from the Landfill Area #1 Site to facilitate implementation of the remainder of the response action.

7. Remove exposed cylinders, waste, containers (e.g., drums) and their contents, and accumulations of waste lead located at the Landfill Area #1 Site encountered during the response action.

8. Remove from the tidal zone of Landfill Area #1 all sediment and soil contaminated by hazardous substances such that the remaining average lead concentration above the water table at low tide is not more than 91.3 mg/kg.

9. Remove up to a depth of 12 inches from the paths traversing Landfill Area # 1 all soil and debris contaminated with lead greater than 1000 mg/kg and such additional lead-contaminated soil such that soil remaining at the surface contains average lead concentrations less than 400 mg/kg.

10. Remove contaminated soil and debris above the high tide line only to the extent necessary to a) implement the response actions described in Items 8 and 9, above, b) develop an appropriate grade and contour to install a soil cover that minimizes erosion of remaining contaminated soil from the Landfill Area # 1 Site, c) facilitate drainage away from paths or trails or structures of Fort DuPont State Park, d) minimize the potential for erosiGn of remaining contaminated soil from the Landfill Area #1 Site into the River, and e) provide for an average surface soil contamination of less than 400 mg/kg lead.

11. Regrade remaining contaminated soil in a manner that promotes drainage, minimizes erosion of the Delaware River bank, and facilitates installation of a cover for contaminated soil.

12. Backfill excavated areas and install a cover on the Landfill Area #1 Site, which minimizes erosion of contaminated soil, provides for continued use of the Landfill Area# 1 Site for current recreational purposes, allows for restoration of vegetative cover, and results in an average surface lead concentration of less than 400 mg/kg.

13. Implement permanent E&S Control facilities, including cover suitable for the Delaware River bank and vegetative cover suitable for the wetland environment. 17

AR300018 14. Dispose of hazardous substances excavated or otherwise segregated for disposal during the above-described activities at an off-Site facility in accordance with 40 C.F.R. § 300.440 and Section 121 (d) of CERCLA.

15. Remove temporary access and security measures for the Landfill Area #1 Site described above and backfill and restore ground disturbed by installation of access and security measures for the Landfill Area #1 Site.

16. Coordinate with State and Local authorities on removal and post-removal activities and conditions intended to, among other things, ensure the continued integrity of the covers and controls installed during the Removal Action.

17. Demobilize personnel and equipment.

B. Contribution to Remedial Performance

The proposed Removal Action is not expected to be inconsistent with or hinder any Remedial Actions at the Landfill Area #1 Site; however, no such Remedial activities are currently expected.

C. Compliance With ARARs

The proposed Removal Action will comply with applicable or relevant and appropriate environmental and health requirements (ARARs), to the extent practicable considering the exigencies of the situation. On December 19,2013, the OSC requested that the State identify all ARARs for this action and is awaiting such identification.

D. Estimated Costs

The proposed distribution of funding is as follows:

Extramural Costs Total Regional Allowance Costs: (ERRS $1,814,900 contractors and subcontractors) Other Extramural Costs Not Funded $105,000 from the Regional Allowance: START Contractor TOTAL REMOVAL ACTION $1,919,900 PROJECT CEILING

AR300019 VII. EXPECTED CHANGE IN SITUATION SHOULD ACTION BE DELAYED OR NOT TAKEN

If no action is taken or the action is delayed, the threat of additional or potential release of hazardous substances from the Landfill Area #1 Site within the Governor Bacon Health Center I Fort DuPont State Park into the environment is inevitable.

VIII. OUTSTANDING POLICY ISSUES

There are no outstanding policy issues pertaining to the Landfill Area #1 Site within the Governor Bacon Health Center I Fort DuPont State Park.

IX. ENFORCEMENT

The EPA Region III Office of Enforcement has been provided with all background information available regarding this Removal Action to pursue enforcement actions pertaining to the Landfill Area #1 Site within the Governor Bacon Health Center I Fort DuPont State Park (See attached Confidential Enforcement Addendum).

The total EPA costs for this removal action based upon full-cost accounting practices that will be eligible for cost recovery are estimated to be $3,342,433. 1

Direct Extramural Costs $ 1,919,900 Direct Intramural Costs $ 80,000 Total, Direct Costs $ 1,999,900

Indirect Costs (67.13% x Direct Costs) $ 1,342,533

Estimated EPA Costs for a Removal Action $ 3,342,433

X. RECOMMENDATION

This Action Memorandum decision document represents the recommended Time-Critical Removal Action for the Landfill Area #1 Site within the Governor Bacon Health Center I Fort DuPont State Park in Delaware City, Delaware, developed in accordance with CERCLA as amended, and not

1Direct Costs include direct extramural costs and direct intramural costs. Indirect costs are calculated based on an estimated indirect cost rate expressed as a percentage of site-specific direct costs, consistent with the full cost accounting methodology effective October 2, 2000. These estimates do not include pre-judgment interest, do not take into account other enforcement costs, including Department of Justice costs, and may be adjusted during the course of a removal action. The estimates are for illustrative purposes only and their use is not intended to create any rights for responsible parties. Neither the lack of a total cost estimate nor deviation of actual total costs from this estimate will affect the United States' right to cost recovery. 19

AR300020 inconsistent with the NCP. Conditions at the Landfill Area #1 Site meet the NCP Section 300.415(b)(2) factors for a removal and I recommend your approval ofthe Removal Action. The total project ceiling will be $1,919,900. Of this, an estimated$ 1,814,900, comes from the Regional Removal Allowance.

Action by the Approving Official:

This Action Memorandum represents the selected Removal Action at the Landfill Area #1 Site within the Governor Bacon Health Center I Fort DuPont State Park in Delaware City, Delaware, developed in accordance with CERCLA as amended, and not inconsistent with the NCP. This decision is based on the administrative record for the Landfill Area #1 Site.

Pursuant to Section 113(k) ofCERCLA, 42 U.S.C. 9613(k) and EPA delegation No. 14-22, I hereby establish the documents identified in Attachment B hereto as the Administrative Record supporting the issuance of the Action Memorandum.

I have reviewed the above-stated facts and based upon those facts and the information compiled in the documents described above, I hereby determine that the release or threatened release of hazardous substances at and/or from the Landfill Area #I Site presents or may present an imminent and substantial endangerment to the public health or welfare or to the environment. I concur with the Removal Action as outlined in the Action Memorandum.

APPROVED: DATE: I (1 ~l( ~ Dav1a Wright, Associate Director Office of Preparedness and Response Hazardous Site Cleanup Division EPA Region 3

Attachments: A. Enforcement Confidential Memo B. Administrative Record documents

AR300021 Administrative Record

Governor Bacon I Ft. DuPont Site, New Castle, Delaware Background

Photo - Aerial Photograph of Ft. DuPont 193 7

Photo - Aerial Photograph of Ft. DuPont 1940

Map - Survey of Ft. DuPont 1941

Map- Survey of Ft. DuPont 1943

Report - Ft. DuPont Delaware: An Architectural Survey and Evaluation 1994

Report- Archeological Survey and Monitoring at Five Investigation Areas, Ft. DuPont, New Castle County, Delaware 2001

Report - Site Inspection Governor Bacon Health Center/ Ft. DuPont State Park, Wilmington, New Castle County, Delaware 2003

Removal Site Evaluation

Data- Region III Data QA Review, dated 1/26/12, Case 42035 SDG MCOAC7; inorganics in surface soil collected in December 2011 Data- Region III Data QA Review, dated 1/26/12, Case 42035 SDG MCOAA5 and MCOAE7; inorganics in surface soil and test pit water collected in December 2011 Data- Region III Data QA Review, dated 1/27112, Case 42035 SDG MCOAAO; inorganics in test pit material collected in December 2011 Data- Region III Data QA Review, dated 4/6/12, Case 42035 SDG MCOAAO; inorganics in test pit material collected in December 2011, AMENDED Data- Region III Data QA Review, dated 2110/12, Case 42035 SDG COAA5, COAA6, COAA1 and COAB3; organics in various media collected in December 2011 Data- Final Analytical Report, dated 5110/12, PCB congeners in water collected December 2011 Data- Test America Data Report, dated 8/28112, TOC and grain size of samples collected in July 2012 Data- Region III Data QA Review, dated 9/14/12, Case 42668 SDG MCOAF8; inorganics in surface water collected in July 2012 Data- Region III Data QA Review, dated 9117112, Case 42668 SDG MCOAHO; inorganics in surface soil collected in July 2012 Data- Region III Data QA Review, dated 9/17112, Case 42668 SDG MCOAG8; TCLP inorganics in surface soil collected in July 2012 Data- Region III Data QA Review, dated 1/10/13, Case 43068 SDG MCOAJ9 and MCOAK5; inorganics in surface and subsurface soil collected in December 2012 Data- Region III Data QA Review, dated 1114/13, Case 43068 SDG COAJ9 and COAK5 Volume Estimate. 10/22/13 memo from Weston to EPA OSC Towle

AR300022 POLREP 01-3/28/12 PO LREP 02 - 8/8/12 POLREP 03- 1/30/13 POLREP 04-3/15/13

Trip Report, March 2012, describing December 2011 field activities Letter Report, October 2012, describing July 2012 field activities Trip Report, March 2013, describing December 2012 field activities

AR300023