MEMORANDUM. Joanne LaBaw, Task Monitor, EPA, Seattle, WA, Mail Stop ECL-122. Linda Ader, START-IV Team Leader, E & E, Seattle, WA

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1 MEMORANDUM DATE: June 21, 2017 TO: FROM: SUBJECT: REF: Joanne LaBaw, Task Monitor, EPA, Seattle, WA, Mail Stop ECL-122 Linda Ader, START-IV Team Leader, E & E, Seattle, WA Revised Proposed Sampling and Assessment Approach Delta Junction - Former Trespass Shooting Range and Former Dump Site Contract Number EP-S Technical Direction Document Number: The U.S. Environmental Protection Agency (EPA) is conducting a Targeted Brownfields Assessment (TBA) at the Delta Junction Former Trespass Shooting Range and Former Dump Site, which is located in. On November 15, 2016, a proposed sampling strategy memo was prepared and provided to project stakeholders that outlined the sampling program designed for this TBA. Stakeholders for this project include the City of Delta Junction, the Delta Junction Trails Association, the Alaska Department of Natural Resources (ADNR), the Alaska Department of Environmental Conservation (ADEC), and the U.S. Environmental Protection Agency (EPA). That proposed sampling strategy included drilling of 11 borings for the purpose of assessing ground water conditions at the site; however, new information has come to light that has made this work not feasible and likely not necessary. Specifically, the depth to the first occurrence of ground water has been revised from an expectation of less than 30 feet below ground surface (bgs) to approximately 90 to 120 feet bgs based on conversations with a driller having significant experience drilling near the site. Costs associated with drilling 11 borings to 90 or more feet bgs are prohibitive for this project. Since ground water at the site is not expected to be used as a resource under current development plans, the assessment of site ground water conditions at this time is not necessary. The original sampling approach has been revised in this memorandum to eliminate drilling and ground water sampling. Slight modifications to the soil sampling and analytical design at the former trespass shooting range also have been made. These include the elimination of certain grab surface soil samples and their replacement with composite multi-increment samples (MIS) and the inclusion of explosive analysis for soil samples collected at make-shift firing lines to assess whether propellant residues are present at these locations. This sections below outline the site background, potential future site uses, the TBA site visit, the environmental setting, recognized environmental conditions (RECs), and the proposed sampling and analytical strategy.

2 Proposed Sampling and Assessment Approach Site Background: The city of Delta Junction is located in the interior of Alaska on the east bank of the Delta River (Figure 1) approximately 80 miles southeast of Fairbanks, Alaska. The site under investigation for this TBA includes acres of undeveloped land owned by the City of Delta Junction (Tract 8A), and adjacent acres of undeveloped land owned by ADNR (Tract 8B and 8C) (City of Delta Junction 2016) (Figure 2). These lots are situated between the Delta River on the west and Richardson Highway to the east. A concrete plant (Delta Concrete Products, Inc.) operates directly to the north of the site (Figure 3). Additional undeveloped land owned by ADNR is located to the south; portions of which contain a biomass drop-off center for area residents to drop off tree and brush debris for later burning. The portion of the site owned by the City contains an out-of-use trespass shooting range having an earthen berm as a backstop; and a portion of the site owned by ADNR contains a former unauthorized dump site that once was used by the community of Delta Junction for disposing of household waste and other refuse. Due to flooding of Delta Junction by the Delta River and bank erosion, concrete groins and pilings were placed along the east bank of the Delta River in the 1980 s by the U.S. Department of Agriculture, the Soil Conservation Service, and the U.S. Military; and later a gravel and earthen levee was constructed by the Department of Transportation along the east riverbank (City of Delta Junction 2016). On its northern end the levee extends onto portions of Tract 8B and on its southern end the levee extends to near the southern end of town. A dirt road is present on top of the levee. The former dump site was used during the 1970 s until 1982 when a berm was constructed to block vehicular access to the dump. It is this berm that later was used as a shooting range backstop until 2000 when the City placed large rocks at the range access road along Richardson Highway to block cars from entering the property (City of Delta Junction 2016). It is assumed that the berm contains lead and brass from small munitions. Over time, various targets ranging from electronic equipment (microwave ovens, television sets, and radios), boxes, glass and plastic bottles, and aluminum cans were used for shooting practice. It is not known if any of these targets have led to releases of environmental contaminants (SLR 2009). In 1999 or 2000, the original berm was expanded to include the addition of a right (north) side berm. Prior to the expansion, the area on the right side of the berm contained an I-beam and cable fence to allow authorized vehicles access to the road behind the berm. This north side berm expansion was placed in front of the cable fence to entirely block vehicle access to the road behind the berm. A left (south) side berm was part of the original berm construction and was built up in (SLR 2009). A former City Manager once had contacted the Fort Greely Army Base, Environmental Manager to find out if a transfer of the range berm material to a military range berm was possible. Evidently, this idea did not proceeded beyond this initial call. In the summer of 2009, a representative from the Alaska National Guard volunteered to clean up debris at the range. Shortly thereafter National Guard members went to the range to pick up and disposed of target Page 2 of 6

3 Proposed Sampling and Assessment Approach materials strewn around the backstop berm and range floor areas (SLR 2009). Available site file information does not indicate how or where this material was disposed. Neither the former dump site nor the former trespass shooting range have been the subject of an environmental investigation. In 2009, ADNR requested assistance from ADEC s Reuse and Redevelopment (R&R) Program to help determine the magnitude of environmental issues at the former trespass shooting range and to develop a cleanup strategy. ADEC s R&R program accepted the project and worked with its environmental contractor to conduct a site visit, interview individuals knowledgeable of the site, and develop a sampling work plan for use in assessing the environmental condition of the former trespass shooting range and determining the most cost effective path forward for cleanup (City of Delta Junction 2016). During this site visit conducted in August of 2009, a profile was cut into the face of the impact berm and soils were examined for bullets and bullet fragments. Bullets and fragments were noted to a depth of approximately 1 foot. Soils were noted to be fine to medium sand to a depth of 2 feet within the berm. The berm is horseshoe-shaped and upon measuring was found to have a maximum height of 12 feet at the center of its impact portion (Figure 5). This portion of the berm was measured to be 15 feet wide by 18 feet deep across its base. The impact berm and side berms were estimated to contain a total of approximately 350 cubic yards of soils. Spent shell casings, bullet impact marks, spent bullets, disintegrated electronic equipment and varied target debris were noted along the entire length of the range floor from the entrance gate to the impact berm. In addition, three primary firing lines were evident (SLR 2009). Through this work, it was discovered that the shooting range berm had been reworked over time with the result that the original surface areas of the berm had been mixed with deeper berm material. Based on this finding it was determined that the berm likely was contaminated throughout its entire volume. For this reason, and since the berm is small, ADEC s R&R program opted not to sample the berm based on a conclusion that sample results would not to lead to a reduction of the volume of material requiring cleanup. Instead, ADEC s R&R program had a cost estimate developed for removal and off-site disposal of the entire berm. Due to funding limitations, a cleanup at the Delta Junction former trespass shooting range berm was not preformed (City of Delta Junction 2016). Potential Future Site Use: The City on Delta Junction does not have park lands adjacent to the Delta River. The Delta Junction Trails Association has been working with the City to develop a Delta River Walk Park Trail that is envisioned as encompassing the site (Tracts 8A, 8B, and 8C), as well as the entire levee road and possibly portions of ADNR land immediately south of the site (see Figure 4) (City of Delta Junction 2016). Ultimately, the goal would be to connect the levee road/trail on its southern end to a currently existing city trail on the east side of Richardson Highway. Since the city trail extends north to the Delta State Recreation Site located just across Richardson Highway from the subject properties it is hoped that a continuous single trail loop could one day be completed. Page 3 of 6

4 Proposed Sampling and Assessment Approach It is expected that the Delta River Walk Park Trail would allow for biking, walking, and running through the forest and with intermittent views of the Delta River and Alaska Mountain Range beyond; and would result in helping to make Delta Junction more of a destination for outdoor recreation. It is further envisioned that the Delta River Walk Park Trail would serve as a venue for community events such as bike and foot races. TBA Site Visit: As a component of this TBA, the site was visited on August 9, Photographic documentation of the site visit is provided as Attachment 1. The former dump site is located in the northwest section of Tract 8B (Figure 3). During the site visit, the former dump was found to contain several mounds of debris intermixed with soil that were often heavily overgrown with brush, shrubs, and trees (Photos 16 through 25). Most debris was in a highly deteriorated condition in keeping with exposure to the elements for the 35 plus years since the dump was taken out of use. The debris consisted primarily of weathered and rusted metal remaining from various household items, appliances, drums, cans, and car parts; though some glass, plastics, tires, and dimensional lumber were visible (Photos 16 through 25, and 28, 29, and 30). A stack of large concrete pipe cradles is present near the former dump site (Photos 26 and 27). A review of historic aerial photographs from 1952, 1974, 1985, 1999, and 2014 indicates that by 1974 the parcel directly north of the site had been cleared, and that by 1985 the area containing the former dump site had also been cleared. By 1999, the former dump site had become largely overgrown with new vegetation. Historic topographic maps for the years 1952, 1959, 1962, and 1975 also show a clearing in the former dump site area as of 1975 and the development of an east/west trending access road by 1962 on the parcel to the north of the site. The former trespass shooting range berm was found to be U -shaped having dimensions similar to those described in The berm was heavily overgrown with saplings, brush, and grasses (Photos 2, 3, 4, and 13). Shotgun casings were present along most of the range floor from the impact berm to a pull-out area on the north side of the access road (Photos 5 and 8). A number of clay shooting targets were also noted on the range floor (Photo 7). Based on these observations, coupled with the information that debris was removed from the range floor in 2009 by National Guard volunteers, it appears the range has been in use by trespassers since that time. Environmental Setting: Delta Junction is situated in the Delta River valley on the north side of the Alaska Range, known as part of the Tanana-Kuskokwim Lowland Physiographic province. The present day topography of this area is the result of Pleistocene glaciations, as well as the effect of lacustrine and alluvial deposits that accompanies or follows the advance of glaciers. Glacial deposits and alluvium predominate in the Delta Junction area, having created broad, nearly level tracts of land with slopes generally ranging from 0 to 3 percent (KAE 2008). The well-drained soil of the western portion of Delta Junction area mostly alluvial deposits of sand and silt primarily derived from glaciers. The generally consist of a 3- to 6-inch mat of partially decomposed organic material underlain by very fine sandy loam and fine sand to a depth of 2 or 3 feet. Several feet of very gravelly coarse sand, free of permafrost, underlie these Page 4 of 6

5 sediments (KAE 2008). Proposed Sampling and Assessment Approach The Delta River is approximately 330 feet west of the site at an elevation of approximately 1,135 feet and flows north into the Tanana River, approximately 7 miles north of the site at the town of Big Delta. Jarvis Creek is approximately 2 miles south of the site and flows north to northwest into the Delta River (SLR 2009). The entire Delta Junction region is a single ground water aquifer, although some sections may be fairly separate but with some communication of water. In Delta Junction, the water table is generally encountered at 50 to 100 feet bgs (KAE 2008). According to a drilling firm familiar with conditions in Delta Junction, ground water adjacent to the Delta River ranges from 90 to 120 feet bgs. Recognized Environmental Conditions (RECs): RECs and data gaps that have been identified for the Delta Junction Former Trespass Shooting Range and Former Dump Site that will be addressed as part of this TBA include: Former Dump Site: Soil and ground water at the former dump site may be contaminated as a result of former disposal practices. Remaining visible debris primarily consists of weathered and rusted metal remaining from various household items, appliances, drums, cans, and car parts; though some glass, plastics, tires, and dimensional lumber were visible. Potential contaminants include: metals, pesticides, polychlorinated biphenyls (PCBs), semivolatile organic compounds (SVOCs), petroleum-related contaminants including gasoline, diesel, and heavy oils; and volatile organic compounds (VOCs) associated with solvents and gasoline. Former Trespass Shooting Range: The primary contaminants associated with the former trespass shooting range are heavy metals, particularly lead, that are present in bullets and gun shot. Additionally, over time, various targets ranging from clay discs, electronic equipment (microwave ovens, television sets, and radios), boxes, glass and plastic bottles, and aluminum cans have been used for shooting practice. Of these, clay targets are often associated with SVOCs contamination and other target items can be associated with heavy metals. Further propellant residues often are found in soils near firing lines at small arms gun ranges. Sampling and Analytical Strategy: Former Dump Site: Seven test pits will be excavated at the former dump site to profile soil and debris horizons and to collect soil samples. Due to soil/debris mounding and vegetative overgrowth, most of the dump is not accessible to vehicles. A trail is present along most of the western edge of the dump allowing access to this side of the dump. For this reason, all borehole locations will placed be near this western edge. Excavation of test pits will allow for profiling debris. The test pits will be excavated to native soil, or to a maximum of 8 feet bgs. Up to two subsurface soil samples will be collected from each test pit to determine whether contaminants of concern are present (i.e., 14 soil samples total). Proposed test pit locations are depicted on Figure 6, but the actual locations Page 5 of 6

6 Proposed Sampling and Assessment Approach selected will be largely driven by field observations of debris and available access points. All soil samples will undergo analyses for metals, pesticides, PCBs, SVOCs, gasolinerange organics, diesel-range organics, residual-range organics, and VOCs. Former Trespass Shooting Range: The former trespass shooting range berm has been reworked over time such that its entire volume may be contaminated. The heaviest contamination is expected to be within the impact portion of the berm. For this reason, sampling efforts will focus on this area of the berm. A total of six excavations will be made into the berm, with four placed within the primary impact zone and one on each of the two side berms near the impact berm (Figure 7). Up to three soil samples will be collected at each excavation: one at or near the surface of the berm, one approximately 1 foot into the berm material, and one approximately 3 feet into the berm material (i.e., 18 samples total). All of these samples will be submitted for fixed laboratory metals analysis, and one sample from each excavation will be submitted for synthetic precipitation leaching procedure analysis (i.e., six samples). With regard to the range floor, MIS approach will be used to collect surface soil samples in areas likely to have the greatest contamination. In total, four decision units will be established, with one on the range floor near the impact berm and one at each of the three primary firing lines. A total of four MIS surface soil samples will be collected from the decision units depicted on Figure 7. All of these samples will be submitted for metals, SVOCs, and explosives (i.e., propellant residue) analysis. Samples of Opportunity: Due to the uncertainty of site conditions, additional samples may be collected based on observations made during the field sampling event in order to better assess the site. Up to three additional test pits may be excavated and up to six additional soil samples may be collected. Decisions regarding the need and placement of these samples will be made in consultation with the EPA Task Monitor as will selection of the analytical suite to be applied. References: City of Delta Junction Targeted Brownfields Assessment Questionnaire, Delta Trespass Shooting Range and Dumping Area. KAE (KAE, Inc.) City of Delta Junction, Delta Junction Water and Sewer Feasibility Study, Final Draft. Prepared for the City of Delta Junction. February SLR (SLR International Corp) Draft Work Plan, Site Characterization, DNR Trespass Shooting Range,. Submitted to the Alaska Department of Environmental Conservation, Brownfield Program. October 26, If you have any questions or comments regarding this sampling approach, please contact me at Page 6 of 6

7 FIGURES

8 Source: igage ALASKA Delta Junction Bering Sea Gulf of Alaska Pacific Ocean Approximate Scale in Miles & ecology and environment, inc. Global Environmental Specialists Seattle, Washington DELTA JUNCTION FORMER TRESPASS SHOOTING RANGE AND FORMER DUMP SITE Date: 6/20/17 Figure 1 VICINITY MAP Drawn by: AES 10:START-IV\ \fig 1

9 ADNR Tract 8B City of Delta Junction Tract 8A Section line ADNR Source: Feet & ecology and environment, inc. Global Environmental Specialists Seattle, Washington DELTA JUNCTION FORMER TRESPASS SHOOTING RANGE AND FORMER DUMP SITE Date: 6/20/17 Figure 2 TAX PARCEL MAP Drawn by: AES 10:START-IV\ \fig 2

10 Source: Delta River Landing Strip & ecology and environment, inc. Global Environmental Specialists Seattle, Washington DELTA JUNCTION FORMER TRESPASS SHOOTING RANGE AND FORMER DUMP SITE ,600 Approximate Scale in Feet Date: 6/20/17 Figure 3 SITE MAP Drawn by: AES 10:START IV\ \fig 3

11 Source: & ecology and environment, inc. Global Environmental Specialists Seattle, Washington DELTA JUNCTION FORMER TRESPASS SHOOTING RANGE AND FORMER DUMP SITE Figure 4 DELTA RIVER WALK PARK TRAIL Date: 6/20/17 Drawn by: AES 10:START-IV\ \fig 4

12 FIRING AREA FIRING AREA FIRING AREA Source: October 23, 2009 & ecology and environment, inc. Global Environmental Specialists Seattle, Washington DELTA JUNCTION FORMER TRESPASS SHOOTING RANGE AND FORMER DUMP SITE Date: 6/20/17 Figure 5 FORMER TRESPASS SHOOTING RANGE MAP Drawn by: AES 10:START-IV\ \fig 5

13 Source: Approximate Scale in Feet LEGEND TEST PIT LOCATION & ecology and environment, inc. Global Environmental Specialists Seattle, Washington DELTA JUNCTION FORMER TRESPASS SHOOTING RANGE AND FORMER DUMP SITE Date: 6/20/17 Figure 6 FORMER DUMP SITE PROPOSED TEST PIT LOCATIONS Drawn by: AES 10:START-IV\ \fig 3-1

14 FIRING AREA FIRING AREA FIRING AREA Source: October 23, 2009 DECISION UNIT WOODED / VEGETATED AREA TARGET BERM APPROXIMATE IMPACT AREA EXCAVATION Figure 7 & ecology and environment, inc. Global Environmental Specialists Seattle, Washington DELTA JUNCTION FORMER TRESPASS SHOOTING RANGE AND FORMER DUMP SITE Date: Drawn by: FORMER TRESPASS SHOOTING RANGE PROPOSED SAMPLE LOCATION MAP 6/20/17 AES 10:START-IV\ \fig 3-2

15 ATTACHMENT 1

16 Photo 1 Small burn pile containing household wastes including towels, boots, bottles, cans, and plastic cups. Direction: Southeast Date: 8/9/16 Time: 10:44 Photo 2 Shooting range berm. Approximately 8 to 10 feet high. Used as backstop. Direction: West Date: 8/9/16 Time: 10:58

17 Photo 3 Shooting range berm. Approximately 4 feet high on south side of range. Direction: Southwest Date: 8/9/16 Time: 10:58 Photo 4 Shooting range berm. Approximately 4 feet high on south side of range. Direction: Southeast Date: 8/9/16 Time: 10:58

18 Photo 5 Shot gun casings on the ground at the gun range. Photo 6 Former gun range from east end. Direction: Down Date: 8/9/16 Time: 11:00 Direction: West Date: 8/9/16 Time: 11:03

19 Photo 7 Clay targets. Photo 8 Shot gun casings littering the ground on east end of range. Direction: Down Date: 8/9/16 Time: 11:03 Direction: West Date: 8/9/16 Time: 11:03

20 Photo 9 Richardson Highway and road to medical clinic at gun range access point. Direction: East Date: 8/9/16 Time: 11:10 Photo 10 Range access road with blocking boulders. Direction: West Date: 8/9/16 Time: 11:10

21 Photo 11 ATV trail from range access road looking south. Photo 12 ATV trail from range access road looking north. Direction: South Date: 8/9/16 Time: 11:10 Direction: North Date: 8/9/16 Time: 11:10

22 Photo 13 West side (i.e., back side) of gun range berm. Photo 14 Delta River from northwest corner of state land. Direction: East Date: 8/9/16 Time: 11:23 Direction: West Date: 8/9/16 Time: 11:35

23 Photo 15 Dump truck from concrete plant north of the site and gravel piles in riverbed. Direction: Northwest Date: 8/9/16 Time: 11:35 Photo 16 Metal debris on north end of site at former dump site. Direction: Southeast Date: 8/9/16 Time: 11:46

24 Photo 17 Metal debris on north end of site at former dump site. Photo 18 Remains of bedframe, large appliances, and timbers at former dump site. Direction: Northeast Date: 8/9/16 Time: 11:46 Direction: East Date: 8/9/16 Time: 11:50

25 Photo 19 Remains of bedframe, large appliances, and timbers at former dump site. Direction: Northwest Date: 8/9/16 Time: 11:50 Photo 20 Large appliances and metal debris. Photo taken to north of Photos 18 and 19. Direction: Northeast Date: 8/9/16 Time: 11:54

26 Photo 21 Empty 55-gallon drum, metal containers, bed springs, cans, sinks, glass, and lumber at former dump site. Direction: North Date: 8/9/16 Time: 11:54 Photo 22 Debris piles to north of Photos 20 and 21. Direction: Northwest Date: 8/9/16 Time: 11:57

27 Photo 23 Cans and bed springs at former dump site. Photo 24 Area east of photos 22 and 23. Contains car frames. Direction: Northeast Date: 8/9/16 Time: 11:57 Direction: Southeast Date: 8/9/16 Time: 12:00

28 Photo 25 Area east of photos 22 and 23. Contains car frames. Photo 26 Concrete pipe cradles south of former dump site. Direction: Northeast Date: 8/9/16 Time: 12:00 Direction: Northeast Date: 8/9/16 Time: 12:11

29 Photo 27 Concrete pipe cradles south of former dump site. Photo 28 Tires south of former dump site. Direction: North Date: 8/9/16 Time: 12:11 Direction: East Date: 8/9/16 Time: 12:16

30 Photo 29 Small southern dump pile with rusted drum, plastic tubing, glass, and plastic containers. Direction: Southeast Date: 8/9/16 Time: 12:18 Photo 30 Small engine and car frame at small southern dump area. Direction: Southeast Date: 8/9/16 Time: 12:18

31 Photo 31 Levee road looking south from top of levee. Levee is approximately 8 feet high along Delta River. Direction: South Date: 8/9/16 Time: 12:25