Results of Environmental Soil Pre-Characterization Sampling.pdf

www.geiconsultants.com 455 Winding Brook Drive, Suite 201 Glastonbury, CT 06033 860.368.5300

Memorandum

To: Michael Maltzan Architecture

From: Jonathan Yeich, LEP

Matthew Glunt, P.E.

Date: September 15, 2025

Re: Results of Environmental Soil Pre-Characterization Sampling

Hartford Courthouse Project

Allyn, Church and High Streets

Hartford, Connecticut 06103

GEI Project Number: 2503909

GEI Consultants, Inc. (GEI) recently conducted environmental soil sampling and testing in an effort to pre-characterize soils that are proposed to be excavated as part of construction activities associated with the project located between Allyn, Church and High Streets in Hartford, Connecticut (hereinafter referred to as “the Site”). The purpose of this memorandum is to summarize the data collected and, in turn, discuss considerations for handling and management of excavated soil during construction.

Project and Site Background

Project design plans are in the conceptual stages, though we understand at this time that new construction is to consist of a 9-story federal courthouse facility with one (1) underground parking level. Based on the current plans, we expect initial site preparations will include excavations up to about 16 or 26 feet in depth, depending on finished grades, to construct the lower-level parking. The resulting subgrade is expected to consist of moist to saturated historic fills or fine-grained native soils.

The building foundation is expected to consist of 1) ground improvements, such as rigid (grouted) piers or similar, followed by conventional foundations or 2) deep, anchored foundations with pile caps and a structural slab.

The Site is currently in use as surface parking lots and consists of 2.19 acres. The Site was historically utilized for multiple commercial and residential purposes from at least the late 1800’s.

From approximately 1986 to 1988, all of the buildings on the Site were demolished to make way for a proposed redevelopment project which never materialized. The Site remained vacant and undeveloped for about 17 years. In 2005 the Site was paved and developed as a private parking lot.

The buildings that previously occupied the Site had multiple commercial uses, ranging from a blacksmith, auto sales/repair, gasoline filling station, auto body repair shop, printing operations, woodworking, a machine shop, restaurants, clothing manufacturing, steam laundry, a YMCA and associated parking, and residential structures.

Sampling and testing was previously conducted at the Site in 2019 by BL Companies and the recent sampling and testing by GEI was conducted to supplement the prior data.

http://www.geiconsultants.com/

Michael Maltzan Architecture -2- September 15, 2025

Subsurface Investigation

Twelve (12) soil boring locations (B-1 through B-10, MW-6, and MW-7) were conducted between July 21, 2025 and August 4, 2025 to evaluate subsurface conditions for geotechnical and environmental purposes. The locations of the soil borings are shown on the attached figure. Each soil boring was conducted using a truck mounted drill rig operated by Seaboard Drilling, LLC. A GEI representative was on site to observe the drilling procedures, classify the soil samples, and record any observed visual or olfactory impacts.

Soil samples were screened in the field with a photo-ionization detector (PID) for the presence of volatile organic compounds (VOCs) using headspace methods.

Two of the investigation locations, MW-6 and MW-7, were completed as monitoring wells. The monitoring wells were developed on August 1, 2025 and sampled on August 6, 2025 using low flow sampling protocols.

Environmental laboratory testing was performed by Connecticut Environmental Testing, Inc. (CET), under subcontract to GEI. Generally, one sample was collected at each soil boring investigation location, totaling 12 soil samples. Grab samples were targeted to be within the urban fill that exhibited the most visual or olfactory impacts. Depth ranges of the samples collected for laboratory analyses at each investigation location are as follows:

Table 1 – Summary of Analytical Sampling

Soil Boring ID Depth Range (ft)

B-1 2-4

B-2 2-4

B-3 6.4-8.4

B-4 4-6

B-5 8-10

B-6 0-2

B-7 2-4

B-8 0-2

B-9 0-2

B-10 0-2

B-10 20-22

MW-7 0-2

The soil samples were tested for the following parameters:

• Volatile Organic Compounds (VOCs) by Environmental Protection Agency (EPA) Method 8260

• Polycyclic Aromatic Hydrocarbons (PAHs) by EPA Method 8270

• Extractable Total Petroleum Hydrocarbons (ETPH) via Connecticut Extractable TPH Method

• Polychlorinated Biphenyl’s (PCBs) via EPA Method 8082

• Resource Conservation Recovery Act (RCRA) 8 total metals, plus Copper, Nickel and Zinc

• Leachable metals via the synthetic precipitation leaching procedure (SPLP) if their total concentrations have the potential to exceed the GB Pollutant Mobility Criteria (GB PMC)

Michael Maltzan Architecture -3- September 15, 2025

(20 times rule).

• Leachable metals via toxicity characteristic leaching procedure (TCLP) if their total concentrations have the potential to exceed hazardous waste thresholds (20 times rule).

Four of the soil samples that exhibited visual or olfactory impacts B-2 (2-4’), B-5 (8-10’), B-10 (0-2’) and MW-7 (0-2’) were also analyzed for the following:

• Semi-Volatile Organic Compounds (SVOCs) by EPA Method 8270 (besides the PAHs already reported)

• Total Antimony, Beryllium, Thallium and Vanadium

• Pesticides via EPA Method 8082

• Herbicides via EPA Method 8151

• Flashpoint

• Corrosivity

• Reactivity

The groundwater samples were tested for the following parameters:

• VOCs by EPA Method 8260

• SVOCs by EPA Method 8270

• ETPH

• PCBs by EPA Method 8082

• Total RCRA 8 total metals plus antimony, beryllium, copper, nickel, thallium, vanadium and zinc

• Dissolved RCRA 8 total metals plus antimony, beryllium, copper, nickel, thallium, vanadium and zinc

Summary tables and laboratory reports are enclosed with this memo.

Subsurface Conditions

All borings with exception of boring B-1 encountered variable historic fill to depths of about 2 feet to 12 feet below current grade. Thickness of historic fill will vary across the site depending on multiple factors such as the previous presence of basements, vaults, tanks, etc. and previous grading operations. The fill soils were generally classified as brown to reddish brown, widely graded sand with silt and gravel, and at times contained minor proportions of debris such as asphalt, brick, and concrete fragments.

Native sandy silts to sandy clays were encountered below the fill stratum, underlain by coarse glacial till soils and weathered to sound Arkose (sandstone) bedrock.

Observed visual or olfactory evidence of impacts was noted in the following soil borings:

Michael Maltzan Architecture -4- September 15, 2025

Soil Boring Observed Evidence of Impacts

B-1 Slight gasoline odor at 30 ft bgs.

B-3 Low level PID responses up to 3 ppmv from approximately 2 to 8 ft bgs within the fill.

B-5 Petroleum odor and moderate PID response of 59 ppmv from approximately 8 to 10 ft bgs within the fill.

B-9 Low level PID responses up to 11 ppmv from approximately 0 to 6 ft bgs within the fill.

B-10 Low level PID responses up to 2 ppmv from approximately 0 to 2 ft bgs within the fill.

Significant gasoline odor and sheen on soil from approximately 20 to 22 ft bgs.

MW-7 Moderate PID responses of up to 32 ppmv from approximately 0 to 4 ft bgs within the fill.

ppmv = parts per million volume ft bgs = feet below ground surface

Depth to groundwater was measured on August 6, 2025, from newly installed wells MW-6 and MW-7 and groundwater was encountered at depths of approximately 14 and 15.5 feet. Groundwater was also measured in eight existing wells and groundwater was encountered at depths between approximately 4.5 and 14 feet.

The subsurface conditions are known only at the sample locations and the subsurface conditions may vary significantly from those described below at other locations. These variations may not become evident until construction.

The soil boring and well installation logs are attached.

Analytical Testing Results

The laboratory testing was completed in accordance with the Connecticut Department of Energy and Environmental Protection (CT DEEP) Laboratory Quality Assurance and Quality Control (QA/QC) Guidance, Reasonable Confidence Protocols Guidance Document (RCPs). Results of the analytical testing of the soil samples collected are summarized below and were compared to Connecticut Remediation Standard Regulations (RSR) criteria:

1. ETPH was detected in 8 of the 12 soil samples with the detections in B-5 (8-10’) at 6,300 milligrams per kilogram (mg/kg) above the Residential Direct Exposure Criteria (RDEC), Industrial / Commercial Direct Exposure Criteria (I/C DEC) and GB Pollutant Mobility

Criteria (GB PMC) and in B-10 (0-2’) at 680 mg/kg above the RDEC.

2. Petroleum related VOCs were detected in 3 of the 12 soil samples with the concentrations of ethylbenzene and total xylenes above the GB PMC in B-10 (20-22’).

3. SVOCs were detected in 10 of the 12 soil samples. The concentrations of PAHs, which are subset of SVOCs, detected in B-2 (2-4’), B-7 (2-4’) and B-10 (0-2’) were above the

RDEC. I/C DEC and/or GB PMC.

4. Total lead was detected at 950 and 990 mg/kg in samples B-3 (6.4-8.4’) and B-7 (2-4’) respectively and above the RDEC.

5. Leachable metals by SPLP were detected in 7 of the 11 samples with the concentrations of SPLP lead in B-3 (6.4-8.4’), B-7 (2-4’) and B-8 (0-2’) above the GB PMC.

6. Leachable lead by TCLP were analyzed for in 6 samples where the total lead concentrations were 100 mg/kg or above. The TCLP lead concentrations were below the hazardous waste threshold of 5 milligrams per liter (mg/l).

7. PCBs were not detected in any of the soil samples.

Michael Maltzan Architecture -5- September 15, 2025

8. Pesticides and herbicides were not detected in the four soil samples analyzed for these parameters. The pH was between 8 and 10 standard units (S.U.), the flashpoint was above 200 degrees Fahrenheit and the soil was not reactive indicating that the soil was not characteristically hazardous for those samples analyzed for these parameters.

Results of the analytical testing of the groundwater samples collected are summarized below:

1. ETPH and SVOCs were not detected in either sample.

2. The only VOC detected was chloroform at a low concentration of 2 micrograms per liter

(ug/l) below the Surface Water Protection Criteria (SWPC), Residential Volatilization Criteria (RVC) and Industrial/Commercial Volatilization Criteria (I/C VC).

3. Several total metals were detected with total arsenic detected above the SWPC in both samples and total lead detected above the SWPC in MW-6.

4. Dissolved metals were detected in both samples with dissolved arsenic detected above the SWPC in MW-7.

Conclusions and Recommendations

The goal of this investigation was to pre-characterize soils that are proposed to be excavated as part of construction activities associated with the project. The sampling and testing was also conducted to supplement the prior data generated for the Site in 2019 by BL Companies.

From our review of the data, the following conclusions and recommendations can be made:

1. A total of 118 soil samples were collected and analyzed between the recent investigation and the sampling conducted in 2019. The primary constituents detected included ETPH, petroleum VOCs, PAHs and select metals.

2. 50 of the soil samples detected one of more contaminants at concentrations above the

CT RSRs RDEC, I/ C DEC and/or GB PMC. The contaminants that exceeded one or more criteria included ETPH, petroleum VOCs, PAHs, antimony, arsenic and lead.

3. Approximately 42 percent of the samples detected one or more contaminants above

RSR criteria. The soils represented by these samples will require disposal or recycling if removed from the site. The remaining soils that have concentrations of contaminants below RSR criteria may be able to be reused on-site or off-site under certain conditions.

4. The distribution of the contaminated soils is not in distinct areas. The distribution is generally widespread across the site.

5. No soil removed from the site should be considered Clean Fill unless further testing of it indicates it is not polluted.

6. The soil was not characteristically hazardous based on the samples that were analyzed.

7. The groundwater was generally not impacted during this investigation except for the presence of metals and those metals may be attributed to the elevated turbidity in the samples upon collection.

8. Previous groundwater sampling and testing at the Site detected ETPH, petroleum related VOCs and SVOCs and total arsenic and lead at concentrations above the

SWPC.

9. Groundwater is present at the Site at depths between approximately 4.5 and 15.5 ft bgs.

Groundwater will likely be encountered during construction activities and will need to be managed accordingly since it is polluted.

Michael Maltzan Architecture -6- September 15, 2025

Attachments: Figure 1 - Test Location Plan Table 1 - Soil Sample Results Summary

Table 2 – Groundwater Monitoring Results Summary Soil Boring Logs and Well Installation Logs Soil and Groundwater Sample Laboratory Analytical Reports Site Plans and Data Tabes from BL Companies 2019 Phase II and III Investigations

Figure 1 – Test Location Plan

FIGURE NO.

GEI PROJECT NO: 2503909

TEST LOCATION PLAN

DOWNTOWN FEDERAL COURTHOUSE – ALLYN STREET SITE

HARTFORD, CT 1

LEGEND

APPROX. TEST BORING LOCATION

SOURCE:

CITY OF HARTFORD GIS

B-4

B-1

B-2

B-3

B-7

B-8

B-10

B-6

B-5

MW-6

B-11/MW-7

B-9

Table 1 – Soil Sample Results Summary Table 2 – Groundwater Monitoring Results Summary

Table 1 - Soil Sample Results Summary

Hartford Courthouse Project

Allyn, Church and High Streets, Hartford, CT

Sample Name B-1(2-4ft) B-2(2-4ft) B-3 (6.4-8.4ft) B-4(4-6ft) B-5 (8-10ft) B-6(0-2ft) B-7(2-4ft) B-8(0-2ft) B-9(0-2ft) B-10(0-2ft) B-10(20-22ft) MW-7(0-2ft)

Sample Depth (ft) 2-4 2-4 6.4-8.4 4-6 8-10 0-2 2-4 0-2 0-2 0-2 20-22 0-2

Date Sampled 7/23/2025 7/23/2025 7/21/2025 8/4/2025 7/21/2025 7/29/2025 8/1/2025 7/31/2025 7/28/2025 7/28/2025 7/29/2025 7/23/2025

Analyte Units RDEC I/C DEC GB PMC Haz

Extractable Total Petroleum Hydrocarbons (ETPH) mg/kg

ETPH 500 2,500 2,500 - <62 220 <61 470 6,300 470 <60 220 140 680 <63 160

Volatile Organic Compounds (VOCs) ug/kg

Ethylbenzene 500,000 1,000,000 10,100 - <4.1 <5.4 <3.6 <220 <100 <3.5 <2.9 <3.1 <3.5 <3.4 19,000 <3.8 isopropylbenzene 500,000* 1,000,000* 5,000* - <4.1 <5.4 <3.6 <220 250 <3.5 <2.9 <3.1 <3.5 <3.4 2,900 <3.8

4-Isopropyltoluene 500,000* 1,000,000* 5,000* - <4.1 <5.4 <3.6 <220 <100 <3.5 <2.9 <3.1 <3.5 <3.4 1,100 <3.8

1,2,4-Trimethylbenzene 500,000* 1,000,000* 28,000* - <4.1 <5.4 <3.6 <220 <100 <3.5 <2.9 <3.1 <3.5 <3.4 28,000 <3.8

1,3,5-Trimethylbenzene 500,000* 1,000,000* 28,000* - <4.1 <5.4 <3.6 <220 <100 <3.5 <2.9 <3.1 <3.5 <3.4 10,000 <3.8

Toluene 500,000 1,000,000 67,000 - <4.1 15 <3.6 <220 <100 <3.5 <2.9 <3.1 <3.5 <3.4 1,000 <3.8

Total Xylenes 500,000 1,000,000 19,500 - <8.2 <11 <3.6 <430 <200 <7.1 <5.9 <6.1 <3.5 <6.8 24,910 <7.6 n-Propylbenzene 500,000* 1,000,000* 10,000* - <4.1 <5.4 <3.6 <220 450 <3.5 <2.9 <3.1 <3.5 <3.4 5,900 <3.8

Naphthalene 1,000,000 2,500,000 56,000 - <8.2 <11 <7.2 <430 <200 <7.1 <5.9 <6.1 <7.0 <6.8 2,900 <7.6

All other VOCs varies varies varies - ND ND ND ND ND ND ND ND ND ND ND ND

Semivolatile Organic Compounds (SVOCs) ug/kg

2-Methylnaphthalene 270,000* 1,000,000* 5,600* - <250 <220 <250 <220 4,100 <220 <240 <220 <230 <230 <250 <210

Acenaphthylene 1,000,000 2,500,000 84,000 - <120 340 <120 <110 160 <110 140 <110 <110 <110 <130 <110

Acenaphthene 1,000,000* 2,500,000* 84,000* - <120 <110 <120 <110 860 <110 420 <110 <110 730 <130 <110

Anthracene 1,000,000 2,500,000 400,000 - <120 330 <120 <110 920 <110 1,500 110 <110 2,900 <130 <110

Benzo(a)anthracene 1,000 7,800 1,000 - <120 1,000 <120 180 190 <110 3,400 410 <110 7,200 <130 530

Benzo(a)pyrene 1,000 1,000 1,000 - <120 1,400 <120 180 190 <110 3,200 430 <110 7,100 <130 710

Benzo(b)fluoranthene 1,000 7,800 1,000 - <120 1,900 140 230 180 <110 3,500 510 130 8,100 <130 840

Benzo(k)fluoranthene 8,400 78,000 1,000 - <120 580 <120 <110 <130 <110 1,400 220 <110 3,800 <130 300

Benzo(g,h,i)perylene 8,400* 78,000* 1,000* - <120 1,200 <120 190 140 <110 2,100 290 <110 4,400 <130 570

Carbazole 31,000 290,000 1,000 - NA 220 NA NA <130 NA NA NA NA 780 NA <110

Chrysene 84,000* 780,000* 1,000* - <120 1,100 <120 240 420 <110 3,400 390 140 6,600 <130 620

Dibenzofuran 68,000 1,000,000 1,400 - NA <110 NA NA 390 NA NA NA NA 410 NA <110

Dibenz(a,h)anthracene 1,000* 1,000* 1,000* - <120 340 <120 <110 <130 <110 490 <110 <110 1,000 <130 130

Indeno(1,2,3-cd)pyrene 1,000* 7,800* 1,000* - <120 1,000 <120 120 <130 <110 1,700 230 <110 3,700 <130 410

Fluoranthene 1,000,000 2,500,000 56,000 - <120 2,000 170 320 370 <110 8,300 760 220 17,000 <130 980

Fluorene 1,000,000 2,500,000 56,000 - <120 <110 <120 <110 1,000 <110 470 <110 <110 830 <130 <110

Naphthalene 1,000,000 2,500,000 56,000 - <120 <110 <120 <110 <130 <110 120 <110 <110 <110 320 <110

Phenanthrene 1,000,000 2,500,000 40,000 - <120 1,000 <120 170 3,100 <110 5,600 350 <110 9,700 <130 250

Pyrene 1,000,000 2,500,000 40,000 - <120 1,700 160 350 910 <110 6,800 710 190 13,000 <130 880

All other SVOCs varies varies varies - ND ND ND ND ND ND ND ND ND ND ND ND

Total Metals mg/kg

Antimony 27 8,200 - - NA <2.2 NA NA <2.5 NA NA NA NA <2.1 NA <2.1

Arsenic 10 10 - - 5.3 3.4 2.5 3.7 4.2 2.6 4.4 3.7 2.4 3.8 NA 2.6

Barium 4,700 140,000 - - 230 70 120 92 160 81 160 150 93 140 NA 57

Beryllium 2 2 - - NA <1.1 NA NA <1.3 NA NA NA NA <1.0 NA <1.1

Cadmium 34 1,000 - - <0.62 <0.54 ND <0.56 <0.64 <0.54 <0.59 <0.56 <0.57 <0.52 NA <0.54

Chromium 3,900/100**51,000/100** - - 45 13 19 15 32 17 23 20 19 23 NA 14

Copper 2,500 76,000 - - 31 33 35 33 26 25 51 43 33 54 NA 22

Lead 400 1,000 - - 29 88 950 190 150 11 990 150 16 100 NA 22

Mercury 20 610 - - <0.15 <0.14 0.80 0.25 1.9 <0.14 0.4 <0.15 <0.14 0.25 NA <0.14

Nickel 1,400 7,500 - - 41 20 17 16 29 18 18 19 19 20 NA 15

Selenium 340 10,000 - - <3.1 <2.7 <3.1 <2.8 <3.2 <2.7 <3.0 <2.8 <2.3 <2.6 NA <2.7

Silver 340 10,000 - - <2.5 <2.2 <2.5 <2.2 <2.5 <2.2 <2.4 <2.2 <2.3 <2.1 NA <2.1

Thallium 5 160 - - NA <2.2 NA NA <2.5 NA NA NA NA <2.1 NA <2.1

Vanadium 470 14,000 - - NA 88 NA NA 49 NA NA NA NA 37 NA 38

Zinc 20,000 610,000 - - 110 110 250 85 120 40 330 140 58 280 NA 45

SPLP Metals mg/L - - -

Barium - - 10 - <0.050 NA NA NA NA NA NA NA NA NA NA NA

Chromium - - 0.5 - <0.050 <0.050 <0.050 <0.050 <0.050 <0.050 <0.050 <0.050 <0.050 <0.050 NA <0.050

Lead - - 0.15 - <0.013 0.031 0.17 0.018 0.019 <0.013 0.27 0.16 0.016 <0.013 NA <0.013

Mercury - - 0.02 - NA NA <0.0020 NA <0.0020 NA NA NA NA NA NA NA

Nickel - - 1 - <0.050 NA NA NA <0.050 NA NA NA NA NA NA NA

TCLP Metals mg/l

TCLP Lead - - - 5 NA NA 3.4 0.36 0.22 NA 3.5 1.4 NA 0.069 NA NA

Polychlorinated Biphenyls (PCBs) mg/kg

Total PCBs 1 10 - - <0.062 <0.054 <0.061 <0.055 <0.066 <0.053 <0.060 <0.055 <0.054 <0.055 NA <0.054

Chlorinated Pesticides ug/kg

All Pesticides varies varies varies - NA ND NA NA ND NA NA NA NA ND NA ND

Chlorinated Herbicides ug/kg

All Herbicides varies varies varies - NA ND NA NA ND NA NA NA NA ND NA ND pH pH - - - <2 & >12.5 NA 8.74 NA NA 8.13 NA NA NA NA 9.79 NA 9.94

Flashpoint F - - - <140 F NA >200 F NA NA >200 F NA NA NA NA >200 F NA >200 F

Reactivity mg/kg

Reactive Sulfide - - - NA <22 NA NA <27 NA NA NA NA <24 NA <22

Reactive Cyanide - - - NA <5.5 NA NA <6.7 NA NA NA NA <6 NA <5.4

Notes:

Only those compounds which were detected are included except for metals where all compounds analyzed for are listed.

Bold text indicates that the compound was detected

Gray shading indicates the compound was detected above one or more criteria

RDEC = Residential Direct Exposure Criteria

I/C DEC = Industrial/Commercial Direct Exposure Criteria

GB PMC = Pollutant Mobility Criteria for Class GB Groundwater Classification Areas

Haz = Hazardous Waste Thresholds ug/l = micrograms per liter mg/l = milligram per liter

ND = not detected

* = Additional Polluting Substances (APS) criteria that can be requested for site specific use

** = trivalent chromium / hexavalent chromium

Not

Reactive

Table 2 - Groundwater Monitoring Results Summary

Hartford Courthouse Project

Allyn, Church and High Streets, Hartford, CT

Sample Name MW-6 MW-7

Date Sampled 8/6/2025 8/6/2025

Water Depth (ft) 15.42 14.10

Analyte Units SWPC R GWVC I/C GWVC

Extractable Total Petroleum Hydrocarbons (ETPH) mg/l

ETPH 0.25* - - <0.050 <0.050

Volatile Organic Compounds (VOCs) ug/l

Chloroform 14,100 26 62 2.4 <1.0

All other VOCs varies varies varies ND ND

Semivolatile Organic Compounds (SVOCs) ug/L

All SVOCs varies varies varies ND ND

Polychlorinated Biphenyls (PCBs) ug/L

Total PCBs 0.5 - - <0.10 <0.10

Total Metals mg/l

Antimony 86 - - <0.050 <0.050

Arsenic 0.004 - - 0.0044 0.016

Barium 2.2 - - 0.38 0.49

Beryllium 0.0004 - - <0.0040 <0.0040

Cadmium 6 - - <0.0050 <0.0050

Chromium 1.2/0.11** - - <0.050 <0.050

Copper 0.048 - - <0.040 <0.040

Lead 0.013 - - 0.015 <0.013

Mercury 0.0004 - - <0.00020 <0.00020

Nickel 0.88 - - <0.050 <0.050

Selenium 50 - - <0.010 <0.010

Silver 12 - - <0.012 <0.012

Thallium 0.063 - - <0.050 <0.050

Vanadium 0.27 - - <0.050 <0.050

Zinc 0.123 - - 0.073 <0.020

Dissolved Metals mg/l

Antimony 86 - - <0.050 <0.050

Arsenic 0.004 - - <0.0040 0.0055

Barium 2.2* - - 0.27 0.4

Beryllium 0.0004 - - <0.0040 <0.0040

Cadmium 0.006 - - <0.0050 <0.0050

Chromium 1.2/0.11** - - <0.050 <0.050

Copper 0.048 - - <0.040 <0.040

Lead 0.013 - - <0.013 <0.013

Mercury 0.0004 - - <0.00020 <0.00020

Nickel 0.88 - - <0.050 <0.050

Selenium 0.05 - - <0.010 <0.010

Silver 0.012 - - <0.012 <0.012

Thallium 0.063 - - <0.050 <0.050

Vanadium 0.27 - - <0.050 <0.050

Zinc 0.123 - - <0.020 <0.020

Notes:

Only those compounds which were detected are included except for metals where all compounds analyzed for are listed.

Bold text indicates that the compound was detected

Gray shading indicates the compound was detected above one or more criteria

SWPC = Surface Water Protection Criteria

R GWVC = Residential Groundwater Volatilization Criteria

I/C GWVC = Industrial/Commercial Groundwater Volatilization Criteria ug/l = micrograms per liter mg/l = milligram per liter

ND = not detected

* = Additional Polluting Substances (APS) criteria that can be requested for site specific use

** = trivalent chromium / hexavalent chromium

Soil Boring Logs and Well Installation Logs

F

IL

L S

A N

D Y

S

IL

T S

IL

T

Y C

L A

Y

4 in. ASPHALT

S1A (0"-12"): WIDELY GRADED SAND WITH GRAVEL (SW);

~60% F-C sand, ~35% F-C gravel, ~5% NP fines, reddish-brown, dry.

S1B (12"-17"): SANDY SILT (ML); ~75% NP fines, ~20% F-M sand, ~5% F-C gravel, reddish-brown, dry.

S2: Similar to S1B.

S3: Similar to S1B, stratified.

S4: Similar to S3.

S5: Similar to S3.

S6: SILTY CLAY (CL); 99.9% LP-MP fines, 0.1% F-sand, reddish-brown, stratified, wet.

PID = 0.1

PID = 0.2

PID = 0.1

PID = 0.0

PID = 0.1

S1

S2

S3

S4

S5

S6

24/17

24/21

24/20

24/18

24/16

24/24

9-4-5-4

4-7-9-9

10-13- 16-16

9-11-13-

7-9-8-11

WOH-

WOH-1-

0.3 to 2.3

2.3 to 4.3

4.3 to 6.3

6.3 to 8.3

8.3 to

10.3 to

U = Undisturbed Sample

SC = Sonic Core

DP = Direct Push Sample

HSA = Hollow-Stem Auger

TOTAL DEPTH (ft): 48.0

RQD = Rock Quality Designation = Length of Sound Cores>4 in / Pen.,%

HAMMER TYPE: Automatic

ABBREVIATIONS:

DRILLING INFORMATION

LOGGED BY: B. Flood

AUGER I.D./O.D.: 4.25 inch / NA

Qp = Pocket Penetrometer Strength

I.D./O.D. = Inside Diameter/Outside Diameter

B-1

Sv = Pocket Torvane Shear Strength

PI = Plasticity Index

NA, NM = Not Applicable, Not Measured

Blows per 6 in.: 140-lb hammer falling

30 inches to drive a 2-inch-O.D.

split spoon sampler.

CASING I.D./O.D.: 4 inch/ NA

CORE BARREL I.D./O.D. NA / NADRILL ROD O.D.: NM

WATER LEVEL DEPTHS (ft): 15.0 7/23/2025 First wet sample.

CORE BARREL TYPE:

WOR = Weight of Rods

WOH = Weight of Hammer

DRILLING METHOD: Hollow Stem Auger/Drill and wash

LL = Liquid Limit

PID = Photoionization Detector

Pen. = Penetration Length

Rec. = Recovery Length

BORING INFORMATION

DRILLER NAME: J. Nitsch/D. Griffin

C = Core Sample

S = Split Spoon Sample

RIG TYPE:

Depth (ft)

Elev.

(ft)

L a y e r

N a m e

Soil and Rock Description Drilling Remarks/ Field Test DataSample

No.

Pen./ Rec.

(in)

Blows per 6 in.

or RQD

Depth (ft)

Sample Information

BORING

VERTICAL DATUM:

GROUND SURFACE EL. (ft): 49

LOCATION: See plan.

DATE START/END: 7/23/2025 - 7/24/2025

DRILLING COMPANY: Seaboard

GEI PROJECT NUMBER: 2503909

PROJECT NAME: Hartford Federal Courthouse

CITY/STATE: Hartford, Connecticut

NOTES:

G

E I

W O

B U

R N

S T

D

-L O

C A

T

IO

N -L

A Y

E R

N A

M E

H

A R

T F

O R

D F

E D

E R

A L

C O

U R

T H

O U

S E

G

IN

T .G

P J

G

I D

A T

A T

E M

P L

A T

E

.G

D T

/5 /2

S

T Y

C L A

Y G

L A

C

IA

L T

IL

L

B E

D R

O C

K

S7: Similar to S6.

S8: Similar to S6.

S9A (0"-22"): Similar to S6.

S9B (22"-24"): SILTY SAND WITH GRAVEL (SM); ~50% F-C

sand, ~30% F-C gravel, ~20% NP fines, reddish-brown, wet.

S10: WIDELY GRADED SAND WITH SILT AND GRAVEL

(SW-SM); ~60% F-C sand, ~30% F-C gravel, ~10% NP fines, reddish-brown, wet.

C1: SANDSTONE/ARKOSE; reddish-brown, medium strong to strong, fine-grained, slightly weathered, close to moderately close joints at 0-40 degrees.

Core times: 14.5, 15.75, 17.75, 13.5, 9.0 min/ft

S7

S8

S9

S10

C1

24/23

24/22

24/24

11/11

60/46

WOH-

WOH-

WOH-1

WOH-

WOH-

WOH-

WOH

WOH-

WOH-

WOH-4

24-50/5" to to to to

35.9 to

B-1

Depth (ft)

Elev.

(ft)

L a y e r

N a m e

Soil and Rock Description Drilling Remarks/ Field Test DataSample

No.

Pen./ Rec.

(in)

Blows per 6 in.

or RQD

Depth (ft)

Sample Information

BORING

VERTICAL DATUM:

GROUND SURFACE EL. (ft): 49

LOCATION: See plan.

DATE START/END: 7/23/2025 - 7/24/2025

DRILLING COMPANY: Seaboard

GEI PROJECT NUMBER: 2503909

PROJECT NAME: Hartford Federal Courthouse

CITY/STATE: Hartford, Connecticut

NOTES:

G

E I

W O

B U

R N

S T

D

-L O

C A

T

IO

N -L

A Y

E R

N A

R

T F

O R

D F

E D

E R

A L

C O

U R

T H

O U

S E

G

IN

T .G

I D

A T

A T

E M

P L

A T

E

.G

B

D R

O C

K

C2: SANDSTONE/ARKOSE; reddish-brown, medium strong to strong, fine-grained, fresh to slightly weathered, close to moderately close joints at 0-40 degrees. Core times: 7.5, 9.0, 9.0, 12.25, 10.25 min/ft.

Planned Extent.

Backfilled with drill cuttings.

C2 60/56 8243 to

B-1

Depth (ft)

Elev.

(ft)

-10

L a y e r

N a m e

Soil and Rock Description Drilling Remarks/ Field Test DataSample

No.

Pen./ Rec.

(in)

Blows per 6 in.

or RQD

Depth (ft)

Sample Information

BORING

VERTICAL DATUM:

GROUND SURFACE EL. (ft): 49

LOCATION: See plan.

DATE START/END: 7/23/2025 - 7/24/2025

DRILLING COMPANY: Seaboard

GEI PROJECT NUMBER: 2503909

PROJECT NAME: Hartford Federal Courthouse

CITY/STATE: Hartford, Connecticut

NOTES:

G

E I

W O

B U

R N

S T

D

-L O

C A

T

IO

N -L

A Y

E R

N A

R

T F

O R

D F

E D

E R

A L

C O

U R

T H

O U

S E

G

IN

T .G

I D

A T

A T

E M

P L

A T

E

.G

L S

IL

T

S

IL

T Y

C L A

Y

4 in. ASPHALT

S1: WIDELY GRADED SAND WITH SILT AND GRAVEL

(SW-SM); ~50% F-C sand, ~40% F-C gravel, ~10% NP fines, brown, dry.

S2: Similar to S1.

S3: Poor recovery. Brick in sampler.

S4: WIDELY GRADED GRAVEL WITH SAND (GW); ~70% F-C

gravel, ~30% F-C sand, brown, dry, with brick fragments.

S5A (0-20"): Similar to S4.

S5B (20-22"): SANDY SILT (ML); ~80% NP fines,~ 20% F-sand, reddish-brown, dry.

S6: SILTY CLAY (CL); 99.7% LP-MP fines, 0.3% F-sand, reddish-brown, stratified, wet.

S7: Similar to S6.

PID = 0.0

PID = 0.0

PID = 0.0

PID = N/A

PID = N/A

S1

S2

S3

S4

S5

S6

S7

24/14

24/9

15/1

24/12

24/9

24/22

24/24

12-26- 10-5

4-6-4-8

8-11- 50/3

9-7-5-5

4-5-5-5

4-5-5-6

2-1-1-1

0.3 to 2.3

2.3 to 4.3

4.3 to 5.6

6.3 to 8.3

8.3 to

10.3

10.3 to

12.3 to

U = Undisturbed Sample

SC = Sonic Core

DP = Direct Push Sample

HSA = Hollow-Stem Auger

TOTAL DEPTH (ft): 31.8

RQD = Rock Quality Designation = Length of Sound Cores>4 in / Pen.,%

HAMMER TYPE: Automatic

ABBREVIATIONS:

DRILLING INFORMATION

LOGGED BY: B. Flood

AUGER I.D./O.D.: 4.25 inch / NA

Qp = Pocket Penetrometer Strength

I.D./O.D. = Inside Diameter/Outside Diameter

B-2

Sv = Pocket Torvane Shear Strength

PI = Plasticity Index

NA, NM = Not Applicable, Not Measured

Blows per 6 in.: 140-lb hammer falling

30 inches to drive a 2-inch-O.D.

split spoon sampler.

CASING I.D./O.D.: 4 inch/ NA

CORE BARREL I.D./O.D. NA / NADRILL ROD O.D.: NM

WATER LEVEL DEPTHS (ft): 10.0 7/23/2025 First wet sample.

CORE BARREL TYPE:

WOR = Weight of Rods

WOH = Weight of Hammer

DRILLING METHOD: Hollow Stem Auger/Drill and wash

LL = Liquid Limit

PID = Photoionization Detector

Pen. = Penetration Length

Rec. = Recovery Length

BORING INFORMATION

DRILLER NAME: J. Nitsch/N. Kern

C = Core Sample

S = Split Spoon Sample

RIG TYPE:

Depth (ft)

Elev.

(ft)

L a y e r

N a m e

Soil and Rock Description Drilling Remarks/ Field Test DataSample

No.

Pen./ Rec.

(in)

Blows per 6 in.

or RQD

Depth (ft)

Sample Information

BORING

VERTICAL DATUM:

GROUND SURFACE EL. (ft): 45

LOCATION: See plan.

DATE START/END: 7/23/2025 - 7/25/2025

DRILLING COMPANY: Seaboard

GEI PROJECT NUMBER: 2503909

PROJECT NAME: Hartford Federal Courthouse

CITY/STATE: Hartford, Connecticut

NOTES:

G

E I

W O

B U

R N

S T

D

-L O

C A

T

IO

N -L

A Y

E R

N A

R

T F

O R

D F

E D

E R

A L

C O

U R

T H

O U

S E

G

IN

T .G

I D

A T

A T

E M

P L

A T

E

.G

T Y

C L A

Y G

L A

C

IA

L T

IL

L

Undisturbed sample

S8: Similar to S6.

S9: Similar to S6.

S10: WIDELY GRADED SAND WITH GRAVEL (SW); ~60%

F-C sand, ~35% F-C gravel, ~5% NP fines, reddish-brown, wet.

Sampler refusal at 31.8 ft.

Backfilled with drill cuttings.

Rig chattering at 28 ft.

T1

S8

S9

S10

24/20

24/24

22/10

WOH-

WOH-1-

WOH-

WOH-

WOH-

WOH

9-10-27- 50/4" to to to to

31.8

B-2

Depth (ft)

Elev.

(ft)

L a y e r

N a m e

Soil and Rock Description Drilling Remarks/ Field Test DataSample

No.

Pen./ Rec.

(in)

Blows per 6 in.

or RQD

Depth (ft)

Sample Information

BORING

VERTICAL DATUM:

GROUND SURFACE EL. (ft): 45

LOCATION: See plan.

DATE START/END: 7/23/2025 - 7/25/2025

DRILLING COMPANY: Seaboard

GEI PROJECT NUMBER: 2503909

PROJECT NAME: Hartford Federal Courthouse

CITY/STATE: Hartford, Connecticut

NOTES:

G

E I

W O

B U

R N

S T

D

-L O

C A

T

IO

N -L

A Y

E R

N A

R

T F

O R

D F

E D

E R

A L

C O

U R

T H

O U

S E

G

IN

T .G

I D

A T

A T

E M

P L

A T

E

.G

L S

A N

D Y

S

IL

T

4 in. ASPHALT S1: SILTY SAND WITH GRAVEL (SM); ~50% F-C sand, ~30% NP fines, ~20% F-C gravel, reddish brown, moist, with asphalt and brick fragments.

S2: SILT WITH SAND AND GRAVEL (ML); ~60% LP-MP Fines, ~25% F-C Gravel, ~15% F-C Sand, reddish brown, moist, with brick fragments.

S3: SANDY SILT (ML); ~70% LP-MP fines, ~20% F-C sand, ~10% F- gravel, brown, moist, with brick fragments.

S4: Similar to S3. Brick fragments, few organic fibers.

S5: Similar to S3. Asphalt and brick fragments.

S6: SANDY SILT (ML); ~80% LP fines, ~20% F-M sand, stratified, brown, moist.

PID = 0.5

PID = 1.5

PID = 1.2

PID = 3.0

PID = 0.1

S1

S2

S3

S4

S5

S6

24/21

24/16

24/16

24/24

24/21

24/15

7-8-22-

7-7-8-6

3-3-3-3

1-2-2-1

2-2-4-3

6-7-10-

0.3 to 2.3

2.3 to 4.3

4.3 to 6.3

6.3 to 8.3

8.3 to

10.3 to

U = Undisturbed Sample

SC = Sonic Core

DP = Direct Push Sample

HSA = Hollow-Stem Auger

TOTAL DEPTH (ft): 39.5

RQD = Rock Quality Designation = Length of Sound Cores>4 in / Pen.,%

HAMMER TYPE: Automatic

ABBREVIATIONS:

DRILLING INFORMATION

LOGGED BY: T. Rezzani

AUGER I.D./O.D.: 4.25 inch / NA

Qp = Pocket Penetrometer Strength

I.D./O.D. = Inside Diameter/Outside Diameter

B-3

Sv = Pocket Torvane Shear Strength

PI = Plasticity Index

NA, NM = Not Applicable, Not Measured

Blows per 6 in.: 140-lb hammer falling

30 inches to drive a 2-inch-O.D.

split spoon sampler.

CASING I.D./O.D.: 4 inch/ NA

CORE BARREL I.D./O.D. NA / NADRILL ROD O.D.: NM

WATER LEVEL DEPTHS (ft): 20.0 7/21/2025 First wet sample.

CORE BARREL TYPE:

WOR = Weight of Rods

WOH = Weight of Hammer

DRILLING METHOD: Hollow Stem Auger/Drill and wash

LL = Liquid Limit

PID = Photoionization Detector

Pen. = Penetration Length

Rec. = Recovery Length

BORING INFORMATION

DRILLER NAME: J. Nitsch

C = Core Sample

S = Split Spoon Sample

RIG TYPE:

Depth (ft)

Elev.

(ft)

L a y e r

N a m e

Soil and Rock Description Drilling Remarks/ Field Test DataSample

No.

Pen./ Rec.

(in)

Blows per 6 in.

or RQD

Depth (ft)

Sample Information

BORING

VERTICAL DATUM:

GROUND SURFACE EL. (ft): 42

LOCATION: See plan.

DATE START/END: 7/21/2025 - 7/21/2025

DRILLING COMPANY: Seaboard

GEI PROJECT NUMBER: 2503909

PROJECT NAME: Hartford Federal Courthouse

CITY/STATE: Hartford, Connecticut

NOTES:

G

E I

W O

B U

R N

S T

D

-L O

C A

T

IO

N -L

A Y

E R

N A

R

T F

O R

D F

E D

E R

A L

C O

U R

T H

O U

S E

G

IN

T .G

I D

A T

A T

E M

P L

A T

E

.G

T Y

C L A

Y G

L A

C

IA

L T

IL

L

S7: SILTY CLAY (CL); ~100% MP fines, reddish brown, stratified, wet.

S8: SANDY SILT WITH GRAVEL (ML); ~60% NP fines, ~25% F-C sand, ~15% F-C gravel, reddish brown, wet.

S9: SILTY SAND WITH GRAVEL (SM); ~40% NP fines, ~30% F-C sand, ~30% F-C gravel, reddish brown, wet.

S10: Similar to S9.

Drill refusal at 39.5 ft.

Backfilled with drill cuttings.

Rig chattering at 28 ft.

Rig chattering at 29 ft.

Rig chattering at 31 ft.

Heavy rig chattering at 36 ft.

S7

S8

S9

S10

24/24

24/11

24/17

9/7

WOH-1-

1-1

4-2-4-9

34-39- 49-39

26-50/3 to to to to

35.8

B-3

Depth (ft)

Elev.

(ft)

L a y e r

N a m e

Soil and Rock Description Drilling Remarks/ Field Test DataSample

No.

Pen./ Rec.

(in)

Blows per 6 in.

or RQD

Depth (ft)

Sample Information

BORING

VERTICAL DATUM:

GROUND SURFACE EL. (ft): 42

LOCATION: See plan.

DATE START/END: 7/21/2025 - 7/21/2025

DRILLING COMPANY: Seaboard

GEI PROJECT NUMBER: 2503909

PROJECT NAME: Hartford Federal Courthouse

CITY/STATE: Hartford, Connecticut

NOTES:

G

E I

W O

B U

R N

S T

D

-L O

C A

T

IO

N -L

A Y

E R

N A

R

T F

O R

D F

E D

E R

A L

C O

U R

T H

O U

S E

G

IN

T .G

I D

A T

A T

E M

P L

A T

E

.G

L S

A N

D Y

S

IL

T S

IL

T

Y C

L A

Y

3 in. ASPHALT

S1: WIDELY GRADED SAND WITH SILT AND GRAVEL

(SW-SM); ~70% F-C sand, ~20% F-C gravel, ~10% NP fines, brown, dry, with brick and concrete fragments.

S2: WIDELY GRADED SAND WITH SILT (SW-SM); ~80% F-C

sand, ~10% F-C gravel, ~10% NP fines, brown, dry, with brick, wood and concrete fragments.

S3: Similar to S2.

S4: SANDY SILT (ML); ~80% NP-LP fines, ~20% F- sand, reddish-brown, wet.

S5: SILTY CLAY (CL); 96.8% LP-MP fines, 2.1% F- sand, 1.1% F- gravel, reddish-brown, stratified, wet.

S6: Similar to S5.

PID = 0.0

PID = 0.0

PID = 0.0

PID = 0.0

PID = 0.0

S1

S2

S3

S4

S5

S6

24/15

24/10

24/9

24/19

24/24

24/24

10-9-5-7

5-5-6-6

9-44-9-7

4-4-5-5

3-4-3-4

2-2-2-2

0.3 to 2.3

2.3 to 4.3

4.3 to 6.3

6.3 to 8.3

8.3 to

10.3 to

U = Undisturbed Sample

SC = Sonic Core

DP = Direct Push Sample

HSA = Hollow-Stem Auger

TOTAL DEPTH (ft): 33.6

RQD = Rock Quality Designation = Length of Sound Cores>4 in / Pen.,%

HAMMER TYPE: Automatic

ABBREVIATIONS:

DRILLING INFORMATION

LOGGED BY: B. Flood

AUGER I.D./O.D.: 4.25 inch / NA

Qp = Pocket Penetrometer Strength

I.D./O.D. = Inside Diameter/Outside Diameter

B-4

Sv = Pocket Torvane Shear Strength

PI = Plasticity Index

NA, NM = Not Applicable, Not Measured

Blows per 6 in.: 140-lb hammer falling

30 inches to drive a 2-inch-O.D.

split spoon sampler.

CASING I.D./O.D.: 4 inch/ NA

CORE BARREL I.D./O.D. NA / NADRILL ROD O.D.: NM

WATER LEVEL DEPTHS (ft): 6.0 8/4/2025 First wet sample.

CORE BARREL TYPE:

WOR = Weight of Rods

WOH = Weight of Hammer

DRILLING METHOD: Hollow Stem Auger/Drill and wash

LL = Liquid Limit

PID = Photoionization Detector

Pen. = Penetration Length

Rec. = Recovery Length

BORING INFORMATION

DRILLER NAME: J. Nitsch

C = Core Sample

S = Split Spoon Sample

RIG TYPE:

Depth (ft)

Elev.

(ft)

L a y e r

N a m e

Soil and Rock Description Drilling Remarks/ Field Test DataSample

No.

Pen./ Rec.

(in)

Blows per 6 in.

or RQD

Depth (ft)

Sample Information

BORING

VERTICAL DATUM:

GROUND SURFACE EL. (ft): 46

LOCATION: See plan.

DATE START/END: 8/4/2025 - 8/4/2025

DRILLING COMPANY: Seaboard

GEI PROJECT NUMBER: 2503909

PROJECT NAME: Hartford Federal Courthouse

CITY/STATE: Hartford, Connecticut

NOTES:

G

E I

W O

B U

R N

S T

D

-L O

C A

T

IO

N -L

A Y

E R

N A

R

T F

O R

D F

E D

E R

A L

C O

U R

T H

O U

S E

G

IN

T .G

I D

A T

A T

E M

P L

A T

E

.G

T Y

C L A

Y G

L A

C

IA

L T

IL

L

S7: Similar to S5.

S8: Similar to S5.

S9: No sample recovery.

S10: Weathered rock fragments in tip of sampler.

Drill refusal at 33.5 ft.

Backfilled with drill cuttings.

Harder drilling noted at 32 ft.

S7

S8

S9

S10

24/24

24/24

24/0

1/0

WOH-

WOH-

WOH-

WOH

WOH-

WOH-

WOH-

WOH

WOH-

WOH-1-

50/1 to to to

33.5 to

33.6

B-4

Depth (ft)

Elev.

(ft)

L a y e r

N a m e

Soil and Rock Description Drilling Remarks/ Field Test DataSample

No.

Pen./ Rec.

(in)

Blows per 6 in.

or RQD

Depth (ft)

Sample Information

BORING

VERTICAL DATUM:

GROUND SURFACE EL. (ft): 46

LOCATION: See plan.

DATE START/END: 8/4/2025 - 8/4/2025

DRILLING COMPANY: Seaboard

GEI PROJECT NUMBER: 2503909

PROJECT NAME: Hartford Federal Courthouse

CITY/STATE: Hartford, Connecticut

NOTES:

G

E I

W O

B U

R N

S T

D

-L O

C A

T

IO

N -L

A Y

E R

N A

R

T F

O R

D F

E D

E R

A L

C O

U R

T H

O U

S E

G

IN

T .G

I D

A T

A T

E M

P L

A T

E

.G

L S

A N

D Y

S

IL

T

5 in. ASPHALT

S1B (5-13"): SILTY GRAVEL WITH SAND (GM); ~50% F-C

gravel, ~30% F-C sand, ~20% NP fines, gray and reddish brown, dry, with asphalt and brick fragments.

S2: SILTY SAND WITH GRAVEL (SM); ~60% F-C sand, ~25% NP fines, ~15% F-C gravel, brown to dark gray, moist, with brick fragments.

S3: SANDY SILT WITH GRAVEL (ML); ~70% LP-MP fines, ~15% F-C sand, ~15% F-C gravel, brown, moist, with asphalt and brick fragments.

S4: Similar to S3.

S5: SANDY SILT (ML); ~80% LP-MP fines, ~15% F-C sand, ~5% F gravel, dark gray, moist, with asphalt and brick fragments.

S6: SILT WITH SAND (ML); ~85% LP fines, ~15% F- sand, gray, wet, wood fragment in sampler.

PID = 1.0

PID = 0.9

PID = 0.2

Slow casing advancement at 6 ft.

PID = 0.1

PID = 59.0

S1

S2

S3

S4

S5

S6

24/13

24/10

24/18

24/11

24/22

24/10

7-12-3-4

7-6-6-4

8-8-8-10

9-7-5-5

4-3-4-4

5-6-9-11 to to to to to to

U = Undisturbed Sample

SC = Sonic Core

DP = Direct Push Sample

HSA = Hollow-Stem Auger

TOTAL DEPTH (ft): 44.0

RQD = Rock Quality Designation = Length of Sound Cores>4 in / Pen.,%

HAMMER TYPE: Automatic

ABBREVIATIONS:

DRILLING INFORMATION

LOGGED BY: T. Rezzani

AUGER I.D./O.D.: 4.25 inch / NA

Qp = Pocket Penetrometer Strength

I.D./O.D. = Inside Diameter/Outside Diameter

B-5

Sv = Pocket Torvane Shear Strength

PI = Plasticity Index

NA, NM = Not Applicable, Not Measured

Blows per 6 in.: 140-lb hammer falling

30 inches to drive a 2-inch-O.D.

split spoon sampler.

CASING I.D./O.D.: 4 inch/ NA

CORE BARREL I.D./O.D. NA / NADRILL ROD O.D.: NM

WATER LEVEL DEPTHS (ft): 14.0 7/21/2025 First wet sample.

CORE BARREL TYPE:

WOR = Weight of Rods

WOH = Weight of Hammer

DRILLING METHOD: Hollow Stem Auger/Drill and wash

LL = Liquid Limit

PID = Photoionization Detector

Pen. = Penetration Length

Rec. = Recovery Length

BORING INFORMATION

DRILLER NAME: J. Nitsch

C = Core Sample

S = Split Spoon Sample

RIG TYPE:

Depth (ft)

Elev.

(ft)

L a y e r

N a m e

Soil and Rock Description Drilling Remarks/ Field Test DataSample

No.

Pen./ Rec.

(in)

Blows per 6 in.

or RQD

Depth (ft)

Sample Information

BORING

VERTICAL DATUM:

GROUND SURFACE EL. (ft): 43

LOCATION: See plan.

DATE START/END: 7/21/2025 - 7/22/2025

DRILLING COMPANY: Seaboard

GEI PROJECT NUMBER: 2503909

PROJECT NAME: Hartford Federal Courthouse

CITY/STATE: Hartford, Connecticut

NOTES:

G

E I

W O

B U

R N

S T

D

-L O

C A

T

IO

N -L

A Y

E R

N A

R

T F

O R

D F

E D

E R

A L

C O

U R

T H

O U

S E

G

IN

T .G

I D

A T

A T

E M

P L

A T

E

.G

N D

Y S

IL

T

G L A

C

IA

L T

IL

L

B O

U L D

E R

S G

L A

C

IA

L T

IL

L

S7: Similar to S6.

S8A (0-6"): Similar to S6, absent wood.

S8B: (6-21"): SANDY SILT (ML); ~50% NP fines, ~40% F-C sand, ~10% F gravel, reddish brown, wet.

S9: GRAVELLY SILT WITH SAND (ML); ~50% NP fines, ~35% F-C gravel, ~15% F-C sand, reddish brown, wet.

C1: Reddish brown sandstone and gray gneiss cobbles to small boulders, 3 in. to 10 in. samples recovered. (Core times: 3.25 min, 3.5 min, 2.5 min, 1 min, 0.75 min).

Drilling bit advanced without sampling at 35.0-40.0 ft.

Slight rig chattering at 26 ft.

Practical drill refusal at 30 ft.

S7

S8

S9

C1

24/3

24/21

10/7

60/16

5-5-7-7

2-2-7-9

21-50/4" to to to

29.8 to

B-5

Depth (ft)

Elev.

(ft)

L a y e r

N a m e

Soil and Rock Description Drilling Remarks/ Field Test DataSample

No.

Pen./ Rec.

(in)

Blows per 6 in.

or RQD

Depth (ft)

Sample Information

BORING

VERTICAL DATUM:

GROUND SURFACE EL. (ft): 43

LOCATION: See plan.

DATE START/END: 7/21/2025 - 7/22/2025

DRILLING COMPANY: Seaboard

GEI PROJECT NUMBER: 2503909

PROJECT NAME: Hartford Federal Courthouse

CITY/STATE: Hartford, Connecticut

NOTES:

G

E I

W O

B U

R N

S T

D

-L O

C A

T

IO

N -L

A Y

E R

N A

R

T F

O R

D F

E D

E R

A L

C O

U R

T H

O U

S E

G

IN

T .G

I D

A T

A T

E M

P L

A T

E

.G

B

D R

O C

K

C2: SANDSTONE/ARKOSE; reddish brown, medium strong to strong, fine-grained, slightly weathered, close to moderately close joints at 0 to 30 degrees. (Core times: 5.25 min, 8.0 min,

8.25 min, 8.75 min).

Planned Extent.

Backfilled with drill cuttings.

Practical drill refusal at 40 ft.

C2 48/44 6140 to

B-5

Depth (ft)

Elev.

(ft)

-10

L a y e r

N a m e

Soil and Rock Description Drilling Remarks/ Field Test DataSample

No.

Pen./ Rec.

(in)

Blows per 6 in.

or RQD

Depth (ft)

Sample Information

BORING

VERTICAL DATUM:

GROUND SURFACE EL. (ft): 43

LOCATION: See plan.

DATE START/END: 7/21/2025 - 7/22/2025

DRILLING COMPANY: Seaboard

GEI PROJECT NUMBER: 2503909

PROJECT NAME: Hartford Federal Courthouse

CITY/STATE: Hartford, Connecticut

NOTES:

G

E I

W O

B U

R N

S T

D

-L O

C A

T

IO

N -L

A Y

E R

N A

R

T F

O R

D F

E D

E R

A L

C O

U R

T H

O U

S E

G

IN

T .G

I D

A T

A T

E M

P L

A T

E

.G

L S

IL

T

S

IL

T Y

C L A

Y

3 in. ASPHALT

S1: WIDELY GRADED SAND WITH SILT AND GRAVEL

(SW-SM); ~60% F-C sand, ~30% F-C gravel, ~10% NP fines, reddish-brown, dry.

S2: Poor recovery. Concrete fragments.

S3: No recovery.

S4: Poor recovery, reddish-brown, dry. Cobble fragments.

S5: SANDY SILT (ML); ~80% NP-LP fines, ~20% F- sand, reddish-brown, moist.

S6: SILTY CLAY (CL); ~100% LP-MP fines, reddish-brown, wet.

PID = 0.0

PID = 0.0

PID = N/A

PID = 0.0

PID = 0.0

S1

S2

S3

S4

S5

S6

24/9

24/2

24/0

24/1

24/24

24/20

7-8-9-8

6-11-22-

5-6-8-8

9-10-9-8

9-10-11-

2-2-3-2

0.3 to 2.3

2.3 to 4.3

4.3 to 6.3

6.3 to 8.3

8.3 to

10.3 to

U = Undisturbed Sample

SC = Sonic Core

DP = Direct Push Sample

HSA = Hollow-Stem Auger

TOTAL DEPTH (ft): 27.0

RQD = Rock Quality Designation = Length of Sound Cores>4 in / Pen.,%

HAMMER TYPE: Automatic

ABBREVIATIONS:

DRILLING INFORMATION

LOGGED BY: B. Flood

AUGER I.D./O.D.: 4.25 inch / NA

Qp = Pocket Penetrometer Strength

I.D./O.D. = Inside Diameter/Outside Diameter

B-6

Sv = Pocket Torvane Shear Strength

PI = Plasticity Index

NA, NM = Not Applicable, Not Measured

Blows per 6 in.: 140-lb hammer falling

30 inches to drive a 2-inch-O.D.

split spoon sampler.

CASING I.D./O.D.: 4 inch/ NA

CORE BARREL I.D./O.D. NA / NADRILL ROD O.D.: NM

WATER LEVEL DEPTHS (ft): 15.0 7/29/2025 First wet sample.

CORE BARREL TYPE:

WOR = Weight of Rods

WOH = Weight of Hammer

DRILLING METHOD: Hollow Stem Auger/Drill and wash

LL = Liquid Limit

PID = Photoionization Detector

Pen. = Penetration Length

Rec. = Recovery Length

BORING INFORMATION

DRILLER NAME: J. Nitsch

C = Core Sample

S = Split Spoon Sample

RIG TYPE:

Depth (ft)

Elev.

(ft)

L a y e r

N a m e

Soil and Rock Description Drilling Remarks/ Field Test DataSample

No.

Pen./ Rec.

(in)

Blows per 6 in.

or RQD

Depth (ft)

Sample Information

BORING

VERTICAL DATUM:

GROUND SURFACE EL. (ft): 44

LOCATION: See plan.

DATE START/END: 7/29/2025 - 7/30/2025

DRILLING COMPANY: Seaboard

GEI PROJECT NUMBER: 2503909

PROJECT NAME: Hartford Federal Courthouse

CITY/STATE: Hartford, Connecticut

NOTES:

G

E I

W O

B U

R N

S T

D

-L O

C A

T

IO

N -L

A Y

E R

N A

R

T F

O R

D F

E D

E R

A L

C O

U R

T H

O U

S E

G

IN

T .G

I D

A T

A T

E M

P L

A T

E

.G

T Y

C L A

Y G

L A

C

IA

L T

IL

L

Undisturbed sample

S7A (0-10"): Similar to S6.

S7B (10"-19"): WIDELY GRADED SAND WITH SILT AND

GRAVEL (SW-SM); ~65% F-C sand, ~25% F-C gravel, ~10% NP fines, reddish-brown, wet.

Planned Extent.

Backfilled with drill cuttings.

T1

S7

24/24

24/19 3-13-16-to to

B-6

Depth (ft)

Elev.

(ft)

L a y e r

N a m e

Soil and Rock Description Drilling Remarks/ Field Test DataSample

No.

Pen./ Rec.

(in)

Blows per 6 in.

or RQD

Depth (ft)

Sample Information

BORING

VERTICAL DATUM:

GROUND SURFACE EL. (ft): 44

LOCATION: See plan.

DATE START/END: 7/29/2025 - 7/30/2025

DRILLING COMPANY: Seaboard

GEI PROJECT NUMBER: 2503909

PROJECT NAME: Hartford Federal Courthouse

CITY/STATE: Hartford, Connecticut

NOTES:

G

E I

W O

B U

R N

S T

D

-L O

C A

T

IO

N -L

A Y

E R

N A

R

T F

O R

D F

E D

E R

A L

C O

U R

T H

O U

S E

G

IN

T .G

I D

A T

A T

E M

P L

A T

E

.G

L S

A N

D Y

S

IL

T

4 in. ASPHALT

S1: WIDELY GRADED SAND WITH GRAVEL (SW); ~60% F-C

sand, ~35% F-C gravel, ~5% NP fines, reddish-black, dry, with brick and concrete fragments.

S2: SILTY SAND WITH GRAVEL (SM); ~60% F-C sand, ~25% F-C gravel, ~15% NP fines, grayish-brown, dry, with brick and concrete fragments, wood.

S3: WIDELY GRADED SAND WITH GRAVEL (SW); ~60% F-C

sand, ~35% F-C gravel, ~5% NP fines, reddish-brown, dry, with brick fragments, wood.

S4: Similar to S3, concrete fragments.

S5: Poor recovery, cobbles.

PID = 0.0

PID = 0.0

PID = 0.0

PID = 0.0

PID = N/A

S1

S2

S3

S4

S5

24/14

24/20

24/9

23/16

10/0

10-16- 13-10

6-10-12-

14-14- 28-48

40-38- 31-50/5"

38-50/4"

0.3 to 2.3

2.3 to 4.3

4.3 to 6.3

6.3 to 8.2

8.3 to 9.1

U = Undisturbed Sample

SC = Sonic Core

DP = Direct Push Sample

HSA = Hollow-Stem Auger

TOTAL DEPTH (ft): 39.2

RQD = Rock Quality Designation = Length of Sound Cores>4 in / Pen.,%

HAMMER TYPE: Automatic

ABBREVIATIONS:

DRILLING INFORMATION

LOGGED BY: B. Flood

AUGER I.D./O.D.: 4.25 inch / NA

Qp = Pocket Penetrometer Strength

I.D./O.D. = Inside Diameter/Outside Diameter

B-7

Sv = Pocket Torvane Shear Strength

PI = Plasticity Index

NA, NM = Not Applicable, Not Measured

Blows per 6 in.: 140-lb hammer falling

30 inches to drive a 2-inch-O.D.

split spoon sampler.

CASING I.D./O.D.: 4 inch/ NA

CORE BARREL I.D./O.D. NA / NADRILL ROD O.D.: NM

WATER LEVEL DEPTHS (ft): 15.0 8/1/2025 First wet sample.

CORE BARREL TYPE:

WOR = Weight of Rods

WOH = Weight of Hammer

DRILLING METHOD: Hollow Stem Auger/Drill and wash

LL = Liquid Limit

PID = Photoionization Detector

Pen. = Penetration Length

Rec. = Recovery Length

BORING INFORMATION

DRILLER NAME: J. Nitsch

C = Core Sample

S = Split Spoon Sample

RIG TYPE:

Depth (ft)

Elev.

(ft)

L a y e r

N a m e

Soil and Rock Description Drilling Remarks/ Field Test DataSample

No.

Pen./ Rec.

(in)

Blows per 6 in.

or RQD

Depth (ft)

Sample Information

BORING

VERTICAL DATUM:

GROUND SURFACE EL. (ft): 41

LOCATION: See plan.

DATE START/END: 8/1/2025 - 8/1/2025

DRILLING COMPANY: Seaboard

GEI PROJECT NUMBER: 2503909

PROJECT NAME: Hartford Federal Courthouse

CITY/STATE: Hartford, Connecticut

NOTES:

G

E I

W O

B U

R N

S T

D

-L O

C A

T

IO

N -L

A Y

E R

N A

R

T F

O R

D F

E D

E R

A L

C O

U R

T H

O U

S E

G

IN

T .G

I D

A T

A T

E M

P L

A T

E

.G

N D

Y S

IL

T

G L A

C

IA

L T

IL

L

S6: SANDY SILT WITH GRAVEL (ML); ~60% NP fines, ~20% F-sand ~20% F-gravel, grayish-brown, wet.

S7A (0-10"): SILT WITH SAND (ML); ~80% NP fines, ~10% F-sand, ~10% F-gravel, grayish-brown, wet.

S7B (10"-20"): SANDY SILT (ML); ~50% NP fines, ~50% F-sand, grayish-brown, wet.

S7C(20"-24"): WIDELY GRADED SAND WITH SILT (SW-SM);

~90% F-C sand, ~10% NP fines, reddish-brown, wet.

S8: WIDELY GRADED SAND WITH SILT AND GRAVEL

(SW-SM); ~60% F-C sand, ~30% F-C gravel, ~10% NP fines, reddish-brown, wet.

S9: WIDELY GRADED SAND WITH GRAVEL (SW); ~65% F-C

sand, ~30% F-C gravel, ~5% NP fines, reddish-brown, wet.

S6

S7

S8

S9

24/8

24/24

24/8

24/10

5-4-5-10

4-5-7-7

5-12-7-7

31-21- 19-20 to to to to

B-7

Depth (ft)

Elev.

(ft)

L a y e r

N a m e

Soil and Rock Description Drilling Remarks/ Field Test DataSample

No.

Pen./ Rec.

(in)

Blows per 6 in.

or RQD

Depth (ft)

Sample Information

BORING

VERTICAL DATUM:

GROUND SURFACE EL. (ft): 41

LOCATION: See plan.

DATE START/END: 8/1/2025 - 8/1/2025

DRILLING COMPANY: Seaboard

GEI PROJECT NUMBER: 2503909

PROJECT NAME: Hartford Federal Courthouse

CITY/STATE: Hartford, Connecticut

NOTES:

G

E I

W O

B U

R N

S T

D

-L O

C A

T

IO

N -L

A Y

E R

N A

R

T F

O R

D F

E D

E R

A L

C O

U R

T H

O U

S E

G

IN

T .G

I D

A T

A T

E M

P L

A T

E

.G

L A

C

IA

L T

IL

L

S10: Similar to S9.

S11: Weathered rock fragments in tip of sampler.

Sampler refusal at 39.2 ft.

Backfilled with drill cuttings.

S10

S11

24/15

2/2

30-45- 40-20

60/2" to to

39.2

B-7

Depth (ft)

Elev.

(ft)

-10

L a y e r

N a m e

Soil and Rock Description Drilling Remarks/ Field Test DataSample

No.

Pen./ Rec.

(in)

Blows per 6 in.

or RQD

Depth (ft)

Sample Information

BORING

VERTICAL DATUM:

GROUND SURFACE EL. (ft): 41

LOCATION: See plan.

DATE START/END: 8/1/2025 - 8/1/2025

DRILLING COMPANY: Seaboard

GEI PROJECT NUMBER: 2503909

PROJECT NAME: Hartford Federal Courthouse

CITY/STATE: Hartford, Connecticut

NOTES:

G

E I

W O

B U

R N

S T

D

-L O

C A

T

IO

N -L

A Y

E R

N A

R

T F

O R

D F

E D

E R

A L

C O

U R

T H

O U

S E

G

IN

T .G

I D

A T

A T

E M

P L

A T

E

.G

L S

IL

T

Y C

L A

Y

3 in. ASPHALT

S1: WIDELY GRADED SAND WITH GRAVEL (SW); ~70% F-C

sand, ~25% F-C gravel, ~5% NP fines, brown, dry, with brick and concrete fragments.

S2: SILTY CLAY (CL); ~95% LP-MP fines, ~5% F-sand, reddish-brown, stratified, dry.

S3: Similar to S2.

S4: Similar to S2.

S5: SILTY CLAY (CL); 99.8% LP-MP fines, 0.2% F-sand, reddish-brown, stratified, dry to moist.

S6: Similar to S5.

PID = 0.0

PID = 0.0

PID = 0.0

PID = 0.0

S1

S2

S3

S4

S5

S6

24/11

24/19

24/24

24/24

24/24

24/24

3-4-5-12

3-3-4-5

3-4-4-5

4-4-5-5

4-3-4-5

1-1-2-1

0.3 to 2.3

2.3 to 4.3

4.3 to 6.3

6.3 to 8.3

8.3 to

10.3 to

U = Undisturbed Sample

SC = Sonic Core

DP = Direct Push Sample

HSA = Hollow-Stem Auger

TOTAL DEPTH (ft): 40.0

RQD = Rock Quality Designation = Length of Sound Cores>4 in / Pen.,%

HAMMER TYPE: Automatic

ABBREVIATIONS:

DRILLING INFORMATION

LOGGED BY: B. Flood

AUGER I.D./O.D.: 4.25 inch / NA

Qp = Pocket Penetrometer Strength

I.D./O.D. = Inside Diameter/Outside Diameter

B-8

Sv = Pocket Torvane Shear Strength

PI = Plasticity Index

NA, NM = Not Applicable, Not Measured

Blows per 6 in.: 140-lb hammer falling

30 inches to drive a 2-inch-O.D.

split spoon sampler.

CASING I.D./O.D.: 4 inch/ NA

CORE BARREL I.D./O.D. NA / NADRILL ROD O.D.: NM

WATER LEVEL DEPTHS (ft): 15.0 7/31/2025 First wet sample.

CORE BARREL TYPE:

WOR = Weight of Rods

WOH = Weight of Hammer

DRILLING METHOD: Hollow Stem Auger/Drill and wash

LL = Liquid Limit

PID = Photoionization Detector

Pen. = Penetration Length

Rec. = Recovery Length

BORING INFORMATION

DRILLER NAME: J. Nitsch

C = Core Sample

S = Split Spoon Sample

RIG TYPE:

Depth (ft)

Elev.

(ft)

L a y e r

N a m e

Soil and Rock Description Drilling Remarks/ Field Test DataSample

No.

Pen./ Rec.

(in)

Blows per 6 in.

or RQD

Depth (ft)

Sample Information

BORING

VERTICAL DATUM:

GROUND SURFACE EL. (ft): 42

LOCATION: See plan.

DATE START/END: 7/31/2025 - 7/31/2025

DRILLING COMPANY: Seaboard

GEI PROJECT NUMBER: 2503909

PROJECT NAME: Hartford Federal Courthouse

CITY/STATE: Hartford, Connecticut

NOTES:

G

E I

W O

B U

R N

S T

D

-L O

C A

T

IO

N -L

A Y

E R

N A

R

T F

O R

D F

E D

E R

A L

C O

U R

T H

O U

S E

G

IN

T .G

I D

A T

A T

E M

P L

A T

E

.G

T Y

C L A

Y G

L A

C

IA

L T

IL

L

S6: Similar to S5.

S6: Similar to S5.

S9: WIDELY GRADED SAND WITH GRAVEL (SW); ~65% F-C

sand, ~30% F-C gravel, ~5% NP fines, reddish-brown, wet.

S10: Similar to S9.

Rig chattering at 28 ft.

S7

S8

S9

S10

24/24

24/24

24/14

4/4

WOH-

WOH-

WOH-

WOH

WOH-

WOH-

WOH-

WOH

7-7-14-

50/4" to to to to

34.3

B-8

Depth (ft)

Elev.

(ft)

L a y e r

N a m e

Soil and Rock Description Drilling Remarks/ Field Test DataSample

No.

Pen./ Rec.

(in)

Blows per 6 in.

or RQD

Depth (ft)

Sample Information

BORING

VERTICAL DATUM:

GROUND SURFACE EL. (ft): 42

LOCATION: See plan.

DATE START/END: 7/31/2025 - 7/31/2025

DRILLING COMPANY: Seaboard

GEI PROJECT NUMBER: 2503909

PROJECT NAME: Hartford Federal Courthouse

CITY/STATE: Hartford, Connecticut

NOTES:

G

E I

W O

B U

R N

S T

D

-L O

C A

T

IO

N -L

A Y

E R

N A

R

T F

O R

D F

E D

E R

A L

C O

U R

T H

O U

S E

G

IN

T .G

I D

A T

A T

E M

P L

A T

E

.G

S11: Black and reddish-brown, weathered rock fragments in tip of sampler.

Sampler refusal at 40.0 ft.

Backfilled with drill cuttings.

S11 0/0 50/0"40 to

B-8

Depth (ft)

Elev.

(ft)

-10

L a y e r

N a m e

Soil and Rock Description Drilling Remarks/ Field Test DataSample

No.

Pen./ Rec.

(in)

Blows per 6 in.

or RQD

Depth (ft)

Sample Information

BORING

VERTICAL DATUM:

GROUND SURFACE EL. (ft): 42

LOCATION: See plan.

DATE START/END: 7/31/2025 - 7/31/2025

DRILLING COMPANY: Seaboard

GEI PROJECT NUMBER: 2503909

PROJECT NAME:…