2021_Jan_19_Pilot_Scale_BBJ_Treatability_Study_Tech_Memo.pdf

U.S. Fish and Wildlife Service / Milton, DE Project No. R2012075

January 19, 2021 Page 1

TECHNICAL MEMORANDUM

Date: January 19, 2021 To: Fred Pinkney, Ph. D., U.S. Fish and Wildlife Service From: Tyler Paulina; Nicholas Dufficy; John Tanaka, P.E.; and J. Tim Bradburne, P.G., BBJ

Group, LLC Subject: Pilot Scale Treatability Study Results, Prime Hook National Wildlife Refuge, Milton, Delaware

Introduction

This Technical Memorandum (TM) summarizes the results of BBJ Group’s pilot scale treatability testing completed for the Prime Hook National Wildlife Refuge (NWR), in Milton, Delaware (Site), pursuant to the Treatability Study Workplan – Lead Shot Site (Workplan) submitted to the United States Fish and Wildlife Service (Service). The Workplan was prepared to evaluate the implementability of in-situ stabilization/solidification (ISS), an alternative recommended in an Engineering Evaluation/Cost Analysis (EE/CA)1 previously prepared for the Site. Bench and pilot scale treatability testing procedures and interpretations of the results as they relate to the treatability study objectives are summarized below. Based on the pilot scale treatability study testing results, BBJ Group finds that ISS can be implemented at full-scale at the Site.

Bench Scale Treatability Testing (September 2020)

Based on the alternative remedial action (i.e., ISS) recommended in the previously prepared EE/CA for the Site, BBJ Group collected two soil and two sediment samples for bench scale treatability testing to

(1) determine the effectiveness of the stabilization regent, (2) evaluate the potential for leaching of chemicals in the stabilization regent, and (3) determine if stabilized materials can be disposed at a permitted off-site non-hazardous waste disposal facility.

The results of the bench-scale treatability testing indicated that a 3% or 4% dosage (by weight) of Enviroblend® CS2 was capable of stabilizing lead impacted soil and sediment to below the hazardous waste level (less than 5 milligrams per liter (mg/L) using the toxicity characteristic leaching procedure [TCLP]) when mixed in a rotary-like fashion (end-over-end) in a laboratory environment. The bench-scale treatability data further indicated that the primary ingredients in the reagent do not appear to pose significant direct contact or leaching risks once applied. Stabilized material was also capable of meeting Delaware Solid Waste Authority’s (DWSA) non-hazardous solid waste disposal criteria3.

Additional details of the bench-scale treatability testing are provided in the TM submitted to the Service by BBJ Group on October 22, 2020.

1 KOMAN Government Solutions, LLC and Geosyntec Consultants, Inc. prepared the Engineering Evaluation/Cost Analysis for the Service, dated December 2017.

2 A proprietary magnesium oxide and hydroxide-based stabilization reagent.

3 https://dswa.com/wp-content/uploads/2015/02/Special-Waste-Policy-Revised-10-27-05.pdf

January 19, 2021 Page 2

Pilot Scale Treatability Testing Methodology and Sampling Procedures (December 2020)

On December 9th through 11th, 2020, BBJ Group conducted pilot scale treatability testing to evaluate if the results of bench-scale testing were reproducible under field conditions. Pilot scale treatability testing procedures and interpretations of the results are summarized below.

ISS Grid Cell Preparation – ISS was performed on eight grid cells approximately five feet long by five feet wide by two feet deep. Specifically, two side-by-side grid cells were centered around each of the four bench-scale sample collection locations, which were selected to evaluate the implementability of ISS across a range of site conditions (i.e., lead shot pellet counts, total lead concentrations, and moisture content). Prior to introducing the reagent (EnviroBlend® CS), a hydraulic excavator pre-excavated each grid cell. Native soils and sediment removed from each grid cell were used to temporarily berm the perimeter of each grid cell. Once each grid cell was excavated to the desired dimensions, preparation and addition of the reagent occurred. Physical characteristics related to each grid cell location is as follows:

Grid Cell ID Previous Bench-Scale Sample ID Matrix

TS-SED-1 BS-SED-1 Sediment

TS-SED-2 BS-SED-1 Sediment

TS-SED-3 BS-SED-2 Sediment

TS-SED-4 BS-SED-2 Sediment

TS-S-1 BSS-2 Soil

TS-S-2 BSS-2 Soil

TS-S-3 BSS-1 Soil

TS-S-4 BSS-1 Soil

Note: One waste characterization composite sample (WC-1) was developed from each grid cell (TS-SED-1, TS-SED-3, TS-S-1 and TS-S-3) that received a 4% dose of EnviroBlend® CS reagent.

Approximate grid cell locations are shown on Figure 1.

Reagent Preparation - The volume of each grid cell was approximately 50 cubic feet, or 1.85 cubic yards.

Assuming a bulk soil density of 1.4 tons/cubic yard, the weight of soil or sediment requiring stabilization in each grid cell was approximately 2.6 tons (5,200 pounds). Based on the two lowest successful dosage ratios determined from bench-scale testing, EnviroBlend® CS was pre-weighed using 5-gallon buckets prior to being introduced into the grid cell. At each of the four bench-scale sample locations, one grid cell received a 3% dose and the adjacent cell received a 4% dose of EnviroBlend® CS reagent, equivalent to approximately 156 and 208 pounds, respectively. The stabilization reagent dosage for each test grid cell is as follows:

January 19, 2021 Page 3

Grid Cell Sample ID Dosage Rate (by Weight)

TS-SED-1 4%

TS-SED-2 3%

TS-SED-3 4%

TS-SED-4 3%

TS-S-1 4%

TS-S-2 3%

TS-S-3 4%

TS-S-4 3%

Soil Mixing –Using a hydraulic excavator equipped with a rotary soil mixing head, reagent was incrementally added into each grid cell as the temporarily bermed pre-excavated soils/sediment were concurrently added back into the cell in 1-foot lifts by a support excavator. The soil/reagent or sediment/reagent mixture was thoroughly mixed via the rotary mixing head until the required quantity of reagent was uniformly distributed throughout the grid cell.

In-situ pH Screening – In-situ pH screening of native soil or sediment was conducted before mixing and during mixing to evaluate the uniformity of reagent distribution in each cell. The mixing process ceased after numerous ‘spot checks’ at different areas and depths of each grid indicated that the pH was at or close to the pH of EnviroBlend® CS (10.0 to 11.0). Typically, the pH of each cell was at or close to the pH of Enviroblend® CS following approximately 20 to 30 minutes of mixing.

Verification Sampling and Laboratory Analysis – One four-point composite sample was collected from each of the eight individual cells and submitted for laboratory analysis. Additionally, one waste characterization composite sample was developed from each grid cell that received a 4% dose of EnviroBlend® CS reagent. In total, nine samples were placed in a cooler containing ice and submitted to Eurofins TestAmerica (Eurofins), Edison, New Jersey for laboratory analysis.

Results

The pilot scale treatability testing results as they relate to objectives outlined in the Workplan are discussed below.

Objective #1: “Identify and confirm whether a lead stabilization reagent can stabilize concentrations of leachable lead in bench and pilot-scale testing to below the TCLP Regulatory Level of 5 mg/L.”

Objective #1 Results: The results of the pilot scale treatability testing (this TM) indicated that EnviroBlend® CS is capable of stabilizing lead leachate to below 5 mg/L under natural field conditions.

Objective #2: “Identify dose(s) of the lead stabilization reagent capable of stabilizing leachable lead to below 5 mg/L.”

January 19, 2021 Page 4

Objective #2 Results: A 4% dose of EnviroBlend® CS (weight of reagent/wet weight of soil) was determined to effectively stabilize lead leachate to below 5 mg/L in all samples collected (includes bench and pilot-scale studies).

While successful within a controlled laboratory environment, a 3% dose of EnviroBlend® CS did not stabilize lead leachate to below 5 mg/L in three of the four samples collected (TS-SED-2, TS-SED-4, TS- S-4).

Total lead concentrations in treated samples ranged between 1,600 milligrams per kilogram (mg/kg) in TS-S-3 to 21,000 mg/kg in TS-S-2. When stabilized with a 4% dose of EnviroBlend® CS, lead leachate ranged from 0.589 mg/L (WC-1) to 2.32 mg/L (TS-S-1).

The pilot scale treatability study results indicate that a 4% dose of EnviroBlend® CS can effectively stabilize lead leachate to below 5 mg/L in soil and sediment containing concentrations of total lead on the order of 1,000 mg/kg to 10,000 mg/kg.

Refer to Table 1 for detailed sample analytical results in treated samples. Complete laboratory analytical reports are provided as Attachment A.

Objective #3: “Identify an in-situ mixing methodology that is capable of stabilizing leachable lead in both aboveground and submerged areas of the Site.”

Objective #3 Results: Grid cells were thoroughly mixed with the reagent using a hydraulic excavator equipped with a rotary mixing head. The results of the pilot scale treatability testing indicate rotary mixing (end-over-end) is an effective large-scale in-situ mixing technique for stabilizing leachable lead in Site soil and sediment.

Objective #4: “Understand performance characteristics of the lead stabilization reagent on different matrices (e.g., soil and sediment).”

Objective #4 Results: Composite samples from each test grid cell containing a soil/reagent and sediment/reagent mixture were collected for pilot scale treatability testing. Additionally, one composite sample from all test grid cells containing a 4% dose of reagent was collected. Moisture content and TCLP lead leachate concentrations in stabilized soil and sediment samples were as follows:

January 19, 2021 Page 5

Sample ID Matrix Moisture (%) Dosage Rate (by weight)

TCLP Pb (mg/L) pH

TS-SED-1 Sediment 37.8 4% 1.31 10.7 TS-SED-2 Sediment 34.6 3% 9.03 10.6 TS-SED-3 Sediment 28.1 4% 0.665 10.8 TS-SED-4 Sediment 26.6 3% 16 10.7

TS-S-1 Soil 20.6 4% 2.32 10.8 TS-S-2 Soil 23.1 3% 1.18 10.7 TS-S-3 Soil 18.6 4% 0.997 10.5 TS-S-4 Soil 15.2 3% 12 10.6

WC-1 N/A 26.5 4% 0.589 10.7

Note: TCLP lead leachate concentrations shaded red exceed the hazardous waste level (5 mg/L).

The pH in all samples collected were within the reagent’s pH range (10 to 11), suggesting unform distribution of the reagent throughout the sample matrix. Since pilot scale data did not show a correlation between pH and TCLP lead concentrations, the results suggest that in-situ pH testing is effective to evaluate the uniformity of reagent distribution, but should not be used predict a passing TCLP result for stabilized soil or sediment. Both the pH and concentration of added reagent were important to stabilize soil.

Objective #5: “Understand the leachability characteristics of active ingredients in the stabilization reagent.”

Objective #5 Results: Concentrations of total magnesium and magnesium leachate in stabilized samples [as analyzed by the Synthetic Precipitation Leaching Procedure (SPLP)] were as follows:

Sample ID Matrix Total Mg (mg/kg) SPLP Mg (ug/L)

TS-SED-1 Sediment 14,300 12,800 TS-SED-2 Sediment 13,500 11,700 TS-SED-3 Sediment 15,500 12,600 TS-SED-4 Sediment 12,200 12,700

TS-S-1 Soil 24,300 13,800 TS-S-2 Soil 16,600 14,100 TS-S-3 Soil 13,000 14,000 TS-S-4 Soil 11,300 15,500 ug/L – micrograms per liter (equivalent to parts per billion)

The total magnesium concentrations reported above generally exceed state background levels4 by an order of magnitude and can likely be attributed to the composition of the reagent. Human health and ecological toxicity data for magnesium are limited, but in general, essential elements such as magnesium, calcium, sodium, and potassium have inherently low toxicities. Likewise, there are no Delaware human health or ecological Hazardous Substance Cleanup Act (HSCA) soil or freshwater sediment screening levels for total magnesium. Magnesium toxicity in plants is rare potentially due

4http://www.dnrec.delaware.gov/dwhs/SIRB/Documents/Statewide%20Soil%20Background%20Study%20- %20Report%20of%20Findings%202012.pdf

January 19, 2021 Page 6 to their large vacuolar storage capacity for magnesium.5 The USEPA Region 3 2006 Biological Technical Assistance Group (BTAG) Freshwater Screening Benchmark6 for magnesium is 82,000 ug/L, representing the lowest chronic value (LCV) for daphnids.

Total iron and leachable iron (via the SPLP) were also analyzed as part of the treatability testing. Total iron ranged from 1,480 mg/kg (in TS-S-1) to 2,580 mg/kg (in TS-SED-2), on the lower end of state background levels. SPLP iron ranged from an estimated concentration of 12.5 ug/L (in TS-S-1) to 326 ug/L (in TS-SED-2). Consistent with the bench-scale treatability study, the pilot scale treatability study results suggest that iron is not present, or is present at negligible quantities, in the reagent and the corresponding leachate concentrations do not present a significant human health or ecological concern.

Concentrations of total phosphorous (as P) and orthophosphate as phosphorus (as PO4) in treated samples as reported by Eurofins are shown in the table below:

Sample ID Matrix Phosphorus (as P) (mg/kg) Phosphorus (as PO4) (mg/kg)

TS-SED-1

Sediment

141 434

TS-SED-2 378 1160

TS-SED-3 377 1150

TS-SED-4 118 361

TS-S-1

Soil

204 625

TS-S-2 362 1110

TS-S-3 88.1 270

TS-S-4 107 327

Consistent with the bench-scale TM, the pilot scale results suggest that phosphorous (or phosphate) is not a primary ingredient in the reagent and is not expected to be a source of leachable phosphorous.

Total nitrate ranged from 0.66 mg/kg (in TS-SED-3) to 1.5 mg/kg (in TS-S-4). Total nitrite was detected at a concentration of 0.21 mg/kg in one of eight samples collected (TS-S-4). Total nitrate and nitrite concentrations are several orders of magnitude below applicable screening levels. The pilot scale treatability study results suggest that nitrite and nitrate are not present, or are present at negligible quantities and do not present a significant human health or ecological concern.

The treatability study data indicate that the primary reagent ingredients do not pose a significant risk to human health or the environment. BBJ Group further notes that if ISS is implemented at full-scale, the reagent will only be in contact with onsite soils and sediment for a matter of hours or days before stabilized soils are subsequently excavated and disposed off-site. Therefore, once removed, the reagent will cease to be a source of magnesium, iron, phosphorous, nitrate and nitrite (or other nutrients).

5https://www.researchgate.net/profile/Nathalie_Verbruggen/publication/257639141_Physiological_and_molecular_responses_ to_magnesium_nutritional_imbalance_in_plants/links/004635296f172a5828000000.pdf 6 https://www.epa.gov/sites/production/files/2015-09/documents/r3_btag_fw_benchmarks_07-06.pdf

January 19, 2021 Page 7

Refer to Table 1 for detailed sample analytical results in untreated and treated samples. Complete laboratory analytical reports are provided as Attachment A.

Objective #6: “Identify and confirm whether the chemical and physical nature of impacted soils and sediment meet additional acceptance criteria for non-hazardous waste disposal at a permitted off-site facility.”

Objective #6 Results: One composite sample of stabilized soil and sediment (WC-1) was developed from equal portions of the four grid cells which received a 4% dosage rate. The sample was analyzed for hazardous waste characteristics and other analyses that are typically needed prior to disposal at a Resource Conservation and Recovery Act (RCRA) Subtitle D non-hazardous solid waste disposal facility (SWDF). A given SWDF may require additional analyses to meet facility-specific requirements.

BBJ Group conducted waste characterization testing in accordance with the Delaware Solid Waste Authority’s (DWSA) Policy on Special Solid Wastes7 (Special Waste Policy). Specifically, the composite sample was analyzed for the following required parameters listed in Section 9 of the Special Waste Policy:

TCLP constituents listed in SW-846 [includes eight RCRA metals and certain volatile organic compounds (VOCs), semivolatile organic compounds (SVOCs), herbicides, and organochlorine pesticides];

Ignitability;

Corrosivity (pH);

Sulfide and cyanide reactivity;

Total benzene, toluene, ethylbenzene, and xylenes (BTEX);

Total polychlorinated biphenyls (PCBs);

Moisture content; and

Free liquid content (paint filter test).

With the exception of total toluene, ethylbenzene and xylenes (total) and TCLP barium and lead, concentrations of the above parameters were neither detected above laboratory reporting limits (RLs) nor the limits specified in Section 9 of the Special Waste Policy. While detected above laboratory RLs, total toluene, ethylbenzene and xylenes (total) and TCLP barium and lead were detected below their applicable regulatory levels. Collectively, the results indicate that stabilized material is capable of meeting DWSA’s non-hazardous solid waste disposal criteria if effectively stabilized in-situ. Laboratory analytical results are summarized in Table 1 and laboratory analytical reports are provided in Attachment A.

7 https://dswa.com/wp-content/uploads/2015/02/Special-Waste-Policy-Revised-10-27-05.pdf

January 19, 2021 Page 8

Recommendations

The results of the treatability study indicate that, on a larger scale, leachable lead in soil and sediment is effectively stabilized to below 5 mg/L using a 4% dose of EnviroBlend® CS and a rotary mixing technique. Additionally, ingredients within the reagent do not appear to present a significant risk to human health or the environment once applied. Full-scale implementation strategies and recommendations will be documented in the forthcoming Remedial Action Workplan (RAWP).

Attachments: Table 1 – Summary of Treatability Study Testing Analytical Results Figure 1 – Site Plan with Grid Cell Locations Attachment A – Laboratory Analytical Reports

TABLE 1

SUMMARY OF TREATABILITY STUDY TESTING ANALYTICAL RESULTS

Table 1 - Summary of Treatability Study Testing Analytical Results (Page 1 of 3)

U.S. Fish and Wildlife Service / Milton, DE BBJ Group Project No. R2012075

Lab ID 460-224814-1 Q 460-224814-2 Q 460-224814-3 Q Sample ID TS-SED-1 (4% EB Treated) TS-SED-2 (3% EB Treated) TS-SED-3 (4% EB Treated)

Sample Date 12/10/2020 12/10/2020 12/10/2020

Matrix Soil Sediment Leachate Sediment Sediment Sediment Analyte, Method, units

Moisture, % NEC NEC NEC 37.8 34.6 28.1

Phosphorus (4500 P E), mg/kg Phosphorus as P NEC NEC NEC 141 378 377 Phosphorus as PO4 NEC NEC NEC 434 1,160 1,150

Total TAL Metals (USEPA 6020B/7471B), mg/kg Aluminum 51,200 NEC N/A 3,520 4,520 4,270 Antimony 3.1 2 N/A 13.9 12.5 6.4 Arsenic 11 9.8 N/A 10.6 12.9 9.1 Barium 1,500 NEC N/A 33.6 29.9 26.1 Beryllium 16 NEC N/A 0.78 0.66 0.39 J Cadmium 7.1 NEC N/A 0.17 U 0.16 U 0.15 U Calcium NEC NEC N/A 2,200 1,880 1,660 Chromium 214 43.4 N/A 3.5 5.1 4.4 Cobalt 34 50 N/A 1.7 J 1.5 J 1.5 J Copper 310 31.6 N/A 2.9 2.7 J 2.2 J Iron 74,767 20,000 N/A 1,910 2,580 2,530 Lead 400 / 421[3] 35.8 / 312[3] N/A 3,710 2,770 2,290 Magnesium NEC NEC N/A 14,300 13,500 15,500 Manganese 2,100 460 N/A 21.7 34.7 22.8 Mercury 1.1 0.18 N/A 0.012 J 0.042 0.0077 J Nickel 150 22.7 N/A 3.2 3.5 3.2 Potassium NEC NEC N/A 132 J 154 154 Selenium 39 2 N/A 0.26 J 0.27 J 0.21 J Silver 39 1 N/A 0.13 U 0.13 U 0.12 U Sodium NEC NEC N/A 37.4 J 34.1 J 31 J Thallium 0.078 NEC N/A 0.067 J 0.069 J 0.068 J Vanadium 134 NEC N/A 5.7 8 7.1 Zinc 2,300 121 N/A 8.6 J 8.9 J 9.0 J

Nitrate/Nitrite (SM4500_NO3_F), mg/kg Nitrate as N 13,000 NEC N/A 1.2 J H3 0.87 J H3 0.66 J H3 Nitrite as N 780 NEC N/A 0.2 U H3 0.2 U H3 0.2 U H3

SPLP Fe, Mg (USEPA 1312/6020B), ug/L Iron NEC NEC N/A 16.8 J B 326 B 17.6 J B Magnesium NEC NEC N/A 12,800 11,700 12,600

TCLP RCRA Metals (USEPA 1311/6010D/7470A), mg/L Arsenic N/A N/A 5 0.0191 J 0.0167 U 0.0167 U Barium N/A N/A 100 0.256 J 0.205 J 0.123 J Lead N/A N/A 5 1.31 9.03 0.665

BTEX (USEPA 8260D), mg/kg Benzene 1.2 NEC N/A NR NR NR Toluene 490 NEC N/A NR NR NR Ethylbenzene 5.8 1.1 N/A NR NR NR Xylenes (total) 58 NEC N/A NR NR NR

PCBs (USEPA 8082A), mg/kg Various Various N/A NR NR NR

Corrosivity (pH) (USEPA 9045D), SU pH NEC NEC NEC 10.7 10.6 10.8

PAHs (USEPA 8270-Delaware), mg/kg Various Various N/A ND ND ND

Reactivity, Sulfide and Cyanide (USEPA 9014 and 9034), mg/kg N/A N/A N/A NR NR NR

Ignitability (USEPA 1030), mm/sec N/A N/A N/A NR NR NR

TCLP Herbicides, Organochlorides, SVOCs, and VOCs (USEPA 1311/8151A/8081B/8270D/8260C), mg/L N/A N/A Various NR NR NR

Paint Filter (Free Liquid) (USEPA 9095B), mL/100g N/A N/A N/A NR NR NR Notes and acronyms on last page

USEPA TCLP

Regulatory Levels[2], mg/L

DNREC HSCA Soil

Screening Levels[1], mg/kg

DNREC HSCA

Freshwater

Sediment Screening

Levels[1], mg/kg

Created by / Date: TJP / 1.11.21 Checked by / Date: AWS/ 1.11.21

(Page 2 of 3)

U.S. Fish and Wildlife Service / Milton, DE BBJ Group Project No. R2012075

Lab ID Sample ID

Sample Date

Matrix Soil Sediment Leachate Analyte, Method, units

Moisture, % NEC NEC NEC

Phosphorus (4500 P E), mg/kg Phosphorus as P NEC NEC NEC Phosphorus as PO4 NEC NEC NEC

Total TAL Metals (USEPA 6020B/7471B), mg/kg Aluminum 51,200 NEC N/A Antimony 3.1 2 N/A Arsenic 11 9.8 N/A Barium 1,500 NEC N/A Beryllium 16 NEC N/A Cadmium 7.1 NEC N/A Calcium NEC NEC N/A Chromium 214 43.4 N/A Cobalt 34 50 N/A Copper 310 31.6 N/A Iron 74,767 20,000 N/A Lead 400 / 421[3] 35.8 / 312[3] N/A Magnesium NEC NEC N/A Manganese 2,100 460 N/A Mercury 1.1 0.18 N/A Nickel 150 22.7 N/A Potassium NEC NEC N/A Selenium 39 2 N/A Silver 39 1 N/A Sodium NEC NEC N/A Thallium 0.078 NEC N/A Vanadium 134 NEC N/A Zinc 2,300 121 N/A

Nitrate/Nitrite (SM4500_NO3_F), mg/kg Nitrate as N 13,000 NEC N/A Nitrite as N 780 NEC N/A

SPLP Fe, Mg (USEPA 1312/6020B), ug/L Iron NEC NEC N/A Magnesium NEC NEC N/A

TCLP RCRA Metals (USEPA 1311/6010D/7470A), mg/L Arsenic N/A N/A 5 Barium N/A N/A 100 Lead N/A N/A 5

BTEX (USEPA 8260D), mg/kg Benzene 1.2 NEC N/A Toluene 490 NEC N/A Ethylbenzene 5.8 1.1 N/A Xylenes (total) 58 NEC N/A

PCBs (USEPA 8082A), mg/kg Various Various N/A

Corrosivity (pH) (USEPA 9045D), SU pH NEC NEC NEC

PAHs (USEPA 8270-Delaware), mg/kg Various Various N/A

Reactivity, Sulfide and Cyanide (USEPA 9014 and 9034), mg/kg N/A N/A N/A

Ignitability (USEPA 1030), mm/sec N/A N/A N/A

TCLP Herbicides, Organochlorides, SVOCs, and VOCs (USEPA 1311/8151A/8081B/8270D/8260C), mg/L N/A N/A Various

Paint Filter (Free Liquid) (USEPA 9095B), mL/100g N/A N/A N/A Notes and acronyms on last page

USEPA TCLP

Regulatory Levels[2], mg/L

DNREC HSCA Soil

Screening Levels[1], mg/kg

DNREC HSCA

Freshwater

Sediment Screening

Levels[1], mg/kg

460-224814-4 Q 460-224814-5 Q 460-224814-6 Q 460-224814-7 Q 460-224814-8 Q 460-224814-9 Q TS-SED-4 (3% EB Treated) TS-S-1 (4% EB Treated) TS-S-2 (3% EB Treated) TS-S-3 (4% EB Treated) TS-S-4 (3% EB Treated) WC-1 (4% EB Treated)

12/11/2020 12/10/2020 12/11/2020 12/11/2020 12/11/2020 12/11/2020

Sediment Soil Soil Soil Soil N/A

26.6 20.6 23.1 18.6 15.2 26.5

118 204 362 88.1 107 NR

361 625 1110 270 327 NR

3,270 2,700 2,500 2,280 2,470 NR

6.3 3.2 4,100 7.1 6.2 NR

7.4 5.8 1,130 5.4 7.1 NR

23.7 15.8 19.9 13.2 18.4 NR

0.34 J 0.13 J 0.17 J 0.12 J 0.13 J NR

0.15 U 0.13 U 0.14 U 0.13 U 0.12 U NR

2,150 3,840 3,010 2,350 1,940 NR

3.3 2.8 2.6 2.3 2.2 NR

1.3 J 0.82 J 0.60 J 0.5 J 0.84 J NR

2.2 J 1.6 J 4.3 1.4 J 1.8 J NR

1,890 1,740 1,540 1,480 1,810 NR

2,010 1,850 21,100 1,600 2,750 NR

12,200 24,300 16,600 13,000 11,300 NR

16.8 16.9 11 12.9 14.4 NR

0.0055 U 0.005 U 0.0062 J 0.0048 U 0.0045 J NR

2.6 1.8 J 1.5 J 1.5 J 1.4 J NR

126 J 83.1 J 70.5 J 65.5 J 81.2 J NR

0.15 U 0.14 U 0.17 J 0.14 U 0.13 J NR

0.11 U 0.11 U 3.5 0.10 U 0.096 U NR

32.3 J 23.8 J 22.1 J 19.7 J 18.9 J NR

0.053 U 0.049 U 0.049 U 0.047 U 0.044 U NR

5.3 4.7 4.5 3.7 4.0 NR

7.1 J 6.5 J 5.3 J 5.5 J 7.8 J NR

0.98 J H3 0.75 J H3 1 J H3 1 J H3 1.5 J H3 NR

0.2 U H3 0.2 U H3 0.2 U H3 0.2 U H3 0.21 J H3 NR

129 B 12.5 J B 15.4 J B 248 B 51.5 J B NR

12,700 13,800 14,100 14,000 15,500 NR

0.111 0.0276 J 0.0167 U 0.0167 U 0.339 0.0167 U

0.185 J 0.0789 J 0.068 J 0.0783 J 0.127 J 0.134 J

16 2.32 1.18 0.997 12 0.589

NR NR NR NR NR 0.0004 U H H3

NR NR NR NR NR 0.00057 J H H3

NR NR NR NR NR 0.0016 H H3

NR NR NR NR NR 0.0088 H H3

NR NR NR NR NR ND

10.7 10.8 10.7 10.5 10.6 10.3

ND ND ND ND ND ND

NR NR NR NR NR ND

NR NR NR NR NR ND

NR NR NR NR NR ND

NR NR NR NR NR ND

Checked by / Date: AWS/ 1.11.21

(Page 3 of 3)

U.S. Fish and Wildlife Service / Milton, DE BBJ Group Project No. R2012075

Notes:

- Only detected analytes are shown. Refer to associated laboratory reports for complete analytical results.

- Indicates exceedance of HSCA Soil Screening Level

- Indicates exceedance of HSCA Freshwater Sediment Screening Level

- Indicates exceedance of USEPA TCLP Regulatory Level

[1] - DNREC HSCA Screening Levels, updated February 2020 [2] - USEPA TCLP Regulatory Levels (40 CFR 261.24), July 1999 [3] - USFWS-calculated site-specific PRG provided for reference [4] - Result reported by Ursus Remediation Testing & Technologies, of Mount Horeb, Wisconsin ND - Analyte(s) not detected above laboratory reporting limits for specific method J - Concentration is an estimated value.

U - Indicates the analyte was analyzed for but not detected.

H - Sample was prepped or analyzed beyond the specific holding time.

H3 - Sample was received and analyzed past holding time.

HF - Field parameter with a holding time of 15 minutes. Test performed by laboratory at client's request.

B - Compound was found in the blank and sample.

Acronyms:

g - gram mg/kg - milligrams per kilogram mg/L - milligrams per liter mL - milliliter mm - millimeter ug/L - micrograms per liter BTEX - benzene, toluene, ethylbenzene, and total xylenes DNREC - Delaware Department of Natural Resources and Environmental Control EB - EnviroBlend® CS Fe - Iron ft bgs - feet below ground surface HSCA - Hazardous Substance Cleanup Act Mg - Magnesium N/A - Not applicable NEC - No established criterion NR - Not analyzed Q - Qualifier PAHs - polycyclic aromatic hydrocarbons PCBs - polychlorinated biphenyls PO4 - Orthophosphate PRG - Preliminary Remediation Goal RCRA - Resource Conservation and Recovery Act SPLP - Synthetic Precipitation Leaching Procedure SVOCs - Semivolatile Organic Compounds TCLP - Toxicity Characteristic Leaching Procedure USEPA - United States Environmental Protection Agency VOCs - Volatile Organic Compounds

Checked by / Date: AWS / 1.11.21

FIGURE 1

SITE PLAN WITH GRID CELL LOCATIONS

ATTACHMENT A

LABORATORY ANALYTICAL REPORT

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