HomeMy WebLinkAboutAppendix H - Phase II Environmental Site Assessment
211 W. Avenida Cordoba, Suite 200 San Clemente, CA 92672 tel 949/361/3902 fax 949/361/3697
November 11, 2025
DLJ Fontana LLC
9895 Double R Blvd.
Reno, NV 89521
Subject: Phase II Environmental Site Assessment - Almond Avenue Trailer Yard
9882 Almond Avenue, Fontana, California 82335
Dear Sir or Madam,
This report has been prepared to present the results of a Phase II Environmental Site Assessment (ESA)
conducted at the properties located at 9882 Almond Avenue in Fontana, California (the Site; Figure 1). HMC
prepared a Phase I ESA for the Site dated March 10, 2025 (HMC, 2025). This ESA included review of previously
prepared ESAs by Partner Engineering and Science (Partner for the two parcels dated May 26, 2022, and July
14, 2022), which found consistent issues as those presented in HMC, 2025 and identified recognized
environmental conditions (RECs) associated primarily with current and historical Site uses and a former gravel
pit.
BACKGROUND
The Site consists of a single parcel with the address of 9882 Almond Avenue in Fontana, California.
Groundwater in the vicinity of the Site was reported at depths between approximately 325 to 375 feet below
ground surface (bgs) and flowing to the south (HMC, 2025).
On-Site operations at 9882 Almond Avenue consist of equipment parking, material storage, an asphalt-paved
parking lot, and paved and unpaved storage yards. A portion of this parcel was a former sand and gravel mine
that was backfilled as part of the mine reclamation with fill from an unknown source. There are no permanent
structures currently present at this portion of the Site.
The primary chemicals of potential concern for the site include volatile organic compounds (VOCs), metals,
total petroleum hydrocarbons (TPH) as gasoline (TPHg), diesel (TPHd), and motor oil (TPHmo), polycyclic
aromatic hydrocarbons (PAHs), and polychlorinated biphenyls (PCBs).
The Phase I ESA identified the following RECs Site:
• Jensen Precast facility features including the clarifier, 10,000-gallon UST, septic system, former dip
tanks, and settling ponds.
• The potential for runoff via the drainage culvert at the Site from the former Kaiser Steel facility to
contain hazardous materials.
• The former gravel pit.
Phase II ESA
9882 Almond Ave.
Fontana, California 82335
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211 W. Avenida Cordoba, Suite 200 San Clemente, CA 92672 tel 949/361/3902 fax 949/361/3697
OBJECTIVES
The objectives of the work summarized herein was to evaluate whether significant releases of hazardous
substances, including VOCs, metals, TPH, PAHs, and PCBs, have occurred at the Site or migrated to the Site from
an off-Site location. Potential releases were evaluated assuming that the Site would continue to be used for
commercial purposes.
DATA EVALUATION CRITERIA
Data collected as part of the Phase II ESA were evaluated against several commonly used screening criteria applied
by the State of California when evaluating whether contaminants could lead to impacts to human health and the
environment and also to evaluate whether the soil, if removed, would be considered hazardous waste. The
following soil and soil vapor criteria for commercial/industrial land use were used to evaluate the data.
Soil Criteria
Soil sampling results were compared to State and Federal screening levels to assess whether detectable
concentrations would present a possible human health risk to commercial/industrial occupants, future
occupants, and the environment. Laboratory analytical results were compared to the following criteria:
• California Department of Toxic Substances Control (DTSC) Soil Screening Levels for
commercial/industrial land use (DTSC-SLi).
• U.S. Environmental Protection Agency (EPA) Region 9 Regional Screening Levels for industrial land
use (EPA-RSLi); and
• San Francisco Bay RWQCB (SFBRWQCB) Environmental Screening Levels for commercial/industrial
shallow soils for direct exposure human health risk (SFBRWQCB-ESLi).
The DTSC-SLi, EPA-RSLi, and SFBRWQCB-ESLi screening values provide human health risk criteria based on dermal
contact, ingestion, and inhalation for VOCs, PAHs, and PCBs. These guidelines are referenced and presented in
Tables 1 and 2 of this report.
Metals are naturally occurring within soil and sediments. With the exception of arsenic, metals data for soil was
compared to the human health risk criteria set forth in DTSC-SLi and EPA-RSLi screening values. Due to the granitic
nature of California geology, naturally occurring background concentrations of arsenic typically exceed the human
health risk guidelines published by the State and federal agencies. As such, arsenic data for soil was evaluated
based on a 12 milligrams per kilogram (mg/kg) threshold, as published in HERO Note 11 (DTSC, 2022). These
screening values are presented in Table 3.
Soil Vapor Criteria
The California DTSC and U.S. EPA have established screening levels for ambient air at commercial/industrial
properties based on human health risk criteria. Subsurface soil vapor screening levels (DTSC-SLi and EPA-RSLi)
Phase II ESA
9882 Almond Ave.
Fontana, California 82335
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211 W. Avenida Cordoba, Suite 200 San Clemente, CA 92672 tel 949/361/3902 fax 949/361/3697
were calculated by dividing the published ambient air screening level concentrations using an EPA-recommended
attenuation factor of 0.03 (33 to 1). The SFBRWQCB provides screening levels for ambient air, sub-slab vapor, and
soil vapor (SFBRWQCB-ESLi) based on human health risk criteria for commercial/industrial settings.
It should be noted that these screening levels are used as guidelines to assess whether a potential human health
risk might be present due to vapor intrusion. However, the values are extremely conservative and do not
necessarily indicate the presence of a risk, but rather that additional Site evaluation, which could include
engineering controls or remediation, is warranted. The soil vapor screening level guidelines are referenced and
presented in Table 4.
SCOPE OF WORK
The Phase II ESA was conducted in April and May 2025 and included the scope of work described in the
following subsections. Sample collection was generally conducted as described below, but in some cases the
sample collection depths may have been adjusted based on field conditions including, but not limited to, Site
lithology or whether drilling refusal was encountered. In general, soil and soil vapor samples were either
collected in areas of potential environmental concern (i.e., near the dip tank or settling pond) and/or evenly
spaced grid pattern spanning across the Site. The field activities for the Phase II investigation including the
sampling and analytical program are summarized in this section.
Soil Testing
Soil samples were tested for the following parameters as summarized in the table below. Duplicate samples
(approximately 2 percent of samples) were collected and analyzed for VOCs only. A total of 39 soil borings,
identified as SB-31 through SB-39, were advanced to 5, 15, 30, 45, or 60 feet bgs at the locations shown on
Figure 2 and described in the table below:
Soil samples collected were tested for the following parameters:
• VOCs by EPA Method 8260B.
• TPH by EPA Method 8015B.
Location Boring ID No. of
Borings
Sample Depth
(feet bgs)
No. of
Soil
Samples Analyses and # of Samples
VOCs TPH Metals
Gravel Pit and
Landfill
Summary Totals 28 18 18 18
Phase II ESA
9882 Almond Ave.
Fontana, California 82335
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211 W. Avenida Cordoba, Suite 200 San Clemente, CA 92672 tel 949/361/3902 fax 949/361/3697
• California Code of Regulations Title 22 (CAM 17) metals including mercury by EPA Methods 6010B and
7471A.
Soil Vapor Testing
• Installed temporary 5- and 15-foot-deep soil vapor probes at borings SB-31 through SB-39 (18 probes).
• Conducted a soil vapor survey that included the collection of 17 soil vapor samples plus including
1 replicate from 17 vapor probes for submittal to a State-certified on-Site mobile laboratory for VOC
analysis by EPA Method 8260B. The temporary soil vapor probe at boring SB -37-5 wasn’t sampled
because it was destroyed prior to the performance of the soil vapor survey.
• Tested 17 soil vapor probes for methane using a Landtec GEM 5000 multi-gas meter.
DISCUSSION OF RESULTS
The following sections summarize the results of the Phase II ESA program.
Soil Sampling Results
As summarized in Tables 1, soil analytical results for VOCs and TPH were either “non-detect” (ND) (i.e., lower
than laboratory reporting limits [RLs]) or reported at concentrations below the corresponding DTSC-SLi, EPA-
RSLi, and SFBRWQCB-ESLi screening levels.
As summarized in Table 2, metals concentrations at all boring locations were either ND or present at levels that
were below regulatory commercial/industrial screening criteria and/or lower than typically naturally-occurring
background levels in California soils.
The total Chromium concentrations at samples SB-31-5 and SB-31-15 of 81 and 170 mg/kg, respectively,
exceeded the soluble threshold limit concentration (STLC) trigger level of 50 mg/kg and sample SB-31-15 also
exceeded the toxicity characteristic leaching procedure (TCLP) trigger level of 100 mg/kg suggesting that the
soluble fraction of chromium could potentially exceed the STLC. Additionally, the chromium concentration in
the SOIL-COMP sample of 61 mg/kg, taken for waste disposal purposes, also exceeded the STLC trigger level.
Based on the exceedances of these trigger levels, the samples were tested to determine the soluble fraction
per the California Waste Extraction Method (DHS WET) for comparison to the STLC and per the federal EPA
Method 1311 for comparison to the TCLP. The results were below the limit of 5 milligrams per liter (mg/L).
Therefore, soil removed from the Site for off-site disposal would not be a California or federal hazardous waste
and could be disposed of as non-hazardous waste based on these results.
Soil Vapor Assessment Results
Soil vapor results confirmed the presence of benzene concentrations exceeding regulatory
commercial/industrial screening levels, The remaining VOCs were either non-detect above laboratory RLs or
below commercial/industrial screening levels.
Phase II ESA
9882 Almond Ave.
Fontana, California 82335
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211 W. Avenida Cordoba, Suite 200 San Clemente, CA 92672 tel 949/361/3902 fax 949/361/3697
Field readings were also taken from soil vapor probes SB-31 through SB-39 with a Landtec Gem 5000 multi-gas
meter to assess the presence of methane due to the unknown source of fill material used to close the former
gravel pit. Following purging of the soil vapor probes, the multi-gas meter measured the percentage by volume
of the lower explosive limit (LEL) of methane. Methane was not detected in any field screening locations
monitored in April and May 2025. Results confirm that methane is not a risk to Site facilities or migrating
through subsurface utilities.
Benzene in Soil Vapor
As shown in Table 3, benzene was detected at 7 out of the 18 samples at concentrations that exceeded the
regulatory screening level of 14 micrograms per meter cubed (µg/m3). The maximum concentration of benzene
detected in soil vapor was 50 µg/m3 at vapor probe location SB-32-5. Although slightly exceeding conservative
screening levels, soil vapor benzene concentrations beneath the Site were generally low and not likely to result
in a vapor intrusion condition based on the following multiple lines of evidence analysis:
• Benzene analytical results for shallow soil were either ND or at low-level concentrations below
regulatory screening levels at 7 of the 18 samples, which is not indicative of a significant release on-
Site or the presence of residual impacts that would pose a potential risk to human health and the
environment.
• Benzene is present in soil vapor at low-level concentrations commonly observed at
commercial/industrial properties and at magnitudes not indicative of a significant impact.
• Based on data collected by HMC from different sites in Los Angeles, Riverside, and San Bernardino
Counties, ambient outdoor air background benzene concentrations at commercial/industrial
properties typically range from approximately 1.5 to 3.0 µg/m3. HMC applied the conservative DTSC-
recommended attenuation factor of 0.03 to the highest detected soil vapor benzene concentration of
50 µg/m3 and calculated a projected indoor concentration for benzene of 1.5 µg/m3. Because this
value is in the typical range of ambient outdoor air background concentrations observed in Southern
California, it can be concluded that background ambient air, not subsurface soil vapor, would likely be
the primary indoor air source for benzene at the Site.
Given the Site’s location within a commercial/industrial land-use area, it is expected that background ambient
air benzene concentrations would be the primary source of benzene to indoor air and that the observed soil
vapor benzene concentrations beneath the Site would not be the primary risk driver to indoor air via the vapor
intrusion pathway. Furthermore, the absence of residual soil impacts combined with the observed presence of
low-level soil vapor benzene detections does not appear to be indicative of a significant release at the Site.
FINDINGS AND CONCLUSIONS
This report presents the results of the Phase II ESA conducted to assess current environmental conditions at
the Site. This investigation included the collection of soil and soil vapor samples to assess whether COCs were
present at levels that that would warrant further action based on the RECs identified in the ESA. The results of
the Phase II ESA support the following observations, findings, and/or conclusions:
Phase II ESA
9882 Almond Ave.
Fontana, California 82335
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211 W. Avenida Cordoba, Suite 200 San Clemente, CA 92672 tel 949/361/3902 fax 949/361/3697
1. Soil VOCs and TPH were either ND or reported at concentrations below the corresponding
DTSC-SLi, EPA-RSLi, and SFBRWQCB-ESLi screening levels at all boring locations.
2. Soil metals results were either below regulatory screening levels or background levels in
California soils, which are representative of naturally occurring concentrations.
3. STLC and TCLP results indicate that if soil were removed from the Site for off-site disposal they
could be disposed of as non-hazardous waste.
4. Although benzene was detected above regulatory screening criteria at 7 out of 18 samples,
the results are not considered a concern. The localized and low-level detection of benzene in
soil vapor is not likely to pose a significant risk to indoor air via the vapor intrusion pathway
and not indicative of a significant release at the Site.
5. Methane monitoring at soil vapor probe locations in the former gravel pit and landfill area
confirm no risk to on-Site occupants of the Site from subsurface methane.
RECOMMENDATIONS
Based on the results of this Phase II ESA, we have no recommendations for remediation at the Site. HM C
recommends the preparation of a Soil Management Plan to guide future grading activities in the event
unforeseen impacts are discovered during development.
We thank you for the opportunity to be of service. If there are any questions or comments regarding this
report, please contact the undersigned at your convenience.
Very truly yours,
Hazard Management Consulting, Inc.
Attachments:
Table 1 – Laboratory Results of Soil Sampling – Petroleum Hydrocarbons and VOCs
Table 2 – Laboratory Results of Soil Sampling - Metals
Table 3 – Laboratory Results of Soil Vapor Sampling
Figure 1 – Site Vicinity Map
Figure 2 – Sample Location Map
Attachment A – Laboratory Reports
Phase II ESA
9882 Almond Ave.
Fontana, California 82335
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211 W. Avenida Cordoba, Suite 200 San Clemente, CA 92672 tel 949/361/3902 fax 949/361/3697
REFERENCES:
DTSC, 2022. “Human Health Risk Assessment (HHRA) Note Number 3, DTSC-modified Screening Levels (DTSC-
SLs),” revised May Chernoff, G., Bosan, W., & Oudiz, D., 2008. “Determination of a Southern California Regional
Background Arsenic Concentration in Soil,” California Department of Toxic Substances Control.
HMC, 2025, Phase One Environmental Site Assessment, Jensen Precast, 14221 San Bernardino Avenue
Fontana California 92335, March 10, 2025.
Partner, 2022a. “Phase I Environmental Site Assessment Report, DJL Fontana, LLC, 14221 San Bernardino
Avenue, Fontana, California,” 26 May.
Partner, 2022b. “Phase I Environmental Site Assessment Report, 9882 Almond Avenue, Fontana, California,”
14 July.
Gasoline
C4-C12
Diesel
C13-C22
Motor Oil
C23-C44 Acetone Benzene
Bromoform
(Tribromo-
methane)
2-Butanone
(MEK)
Carbon
disulfide m,p-Xylene Styrene
Tert-butyl
alcohol Toluene
SB-31-5 5 4/21/25 0.18 J 8.8 267 28 ANC, J ND<2 ND<4 ND<40 ND<40 ND<2 ND<4 ND<20 ND<2
SB-31-15 15 4/21/25 0.20 J 11 217 44 ANC, J 1.5 J ND<4 ND<40 ND<40 2.4 3.8 J 22 ND<2
SB-32-5 5 4/23/25 2.3 21 130 ND<80 ND<2 ND<4 ND<40 ND<40 ND<2 ND<4 27 ND<2
SB-32-15 15 4/23/25 ND<0.5 3.5 67 J ND<80 ND<2 ND<4 ND<40 ND<40 ND<2 ND<4 13 J ND<2
SB-33-5 5 4/22/25 ND<0.5 3.2 74 J 32 ANC, J ND<2 ND<4 ND<40 ND<40 ND<2 ND<4 8.5 J ND<2
SB-33-15 15 4/22/25 ND<0.5 2.0 J 90 J 23 ANC, J ND<2 ND<4 ND<40 ND<40 ND<2 ND<4 ND<20 ND<2
SB-34-5 5 4/21/25 ND<0.5 150 149 ND<80 ND<2 ND<4 ND<40 ND<40 ND<2 ND<4 ND<20 ND<2
SB-34-15 15 4/21/25 ND<0.5 62 984 ND<80 ND<2 ND<4 ND<40 ND<40 ND<2 ND<4 ND<20 ND<2
SB-35-5 5 4/22/25 ND<0.5 17 655 25 ANC, J ND<2 ND<4 ND<40 ND<40 ND<2 ND<4 12 J ND<2
SB-35-15 15 4/22/25 ND<0.5 61 3,530 20 ANC, J ND<2 ND<4 ND<40 ND<40 ND<2 ND<4 ND<20 ND<2
SB-36-5 5 4/23/25 ND<0.5 ND<2.5 ND<100 ND<80 ND<2 ND<4 ND<40 ND<40 ND<2 ND<4 11 J ND<2
SB-36-15 15 4/23/25 ND<0.5 ND<2.5 ND<100 ND<80 ND<2 ND<4 ND<40 ND<40 ND<2 ND<4 11 J ND<2
SB-37-5 5 4/22/25 ND<0.5 7.0 204 29 ANC, J ND<2 ND<4 ND<40 ND<40 ND<2 ND<4 6.2 J ND<2
SB-37-15 15 4/22/25 ND<0.5 24 1,410 ND<80 ND<2 ND<4 ND<40 ND<40 ND<2 ND<4 5.5 J ND<2
SB-38-5 5 4/22/25 ND<0.5 40 614 45 ANC, J ND<2 ND<4 ND<40 ND<40 ND<2 ND<4 ND<20 ND<2
SB-38-15 15 4/22/25 ND<0.5 65 2,260 44 ANC, J ND<2 ND<4 ND<40 ND<40 ND<2 ND<4 ND<20 ND<2
SB-39-5 5 4/23/25 ND<0.5 ND<2.5 ND<100 ND<80 ND<2 ND<4 ND<40 ND<40 ND<2 ND<4 ND<20 ND<2
SB-39-15 15 4/23/25 ND<0.5 ND<2.5 ND<100 ND<80 ND<2 ND<4 ND<40 ND<40 ND<2 ND<4 10 J ND<2
500 NE NE NE 1,400 86,000 NE NE NE 32,000,000 NE 5,300,000
1,700 440 3,500,000 1,100,000,000 5,100 86,000 190,000,000 3,500,000 NE 35,000,000 6,500,000 47,000,000
1,818 1,084 54,452 271,597,000 1,400 79,600 118,759,000 NE NE 24,527,000 NE 4,699,000
Notes:
Sample ID - Sample identification.
bgs - Below ground surface.
Petroleum hydrocarbons analyzed using U.S. Environmental Protection Agency (EPA) Method 8015B or 8260B and reported in milligrams per kilogram (mg/kg).
VOCs - Volatile organic compounds analyzed using U.S. EPA Method 8260B and reported in micrograms per kilogram (ug/kg).
J - Detected but below the Practical Quantitation Limit; therefore, result is an estimated concentration.
ANC - Analyte not Certifiable by California Environmental Laboratory Accreditation Program (CAL ELAP).
ND - Not detected above laboratory reporting limit listed.
"--" - Not analyzed.
EPA-RSLi - U.S. EPA Regional Screening Level for soil for commercial/industrial land use (RSLi), updated in November 2023.
NE - Not established.
Bolded and highlighted data in light blue indicate concentrations exceeding regualtory screening levels.
DTSC-SLi - California Department of Toxic Substance Control (DTSC), Human and Ecological Risk Office Note 3, modified soil screening levels for commercial/industrial land use (SLi), revised in May 2022.
SFBRWQCB-ESLi - San Francisco Bay Regional Water Quality Control Board (SFWRQCB), Environmental Screening Levels (ESLs) Workbook, for direct exposure human health risk level for commercial/industrial soil, dated 2019 Rev. 2
TABLE 1 - LABORATORY RESULTS OF SOIL SAMPLING - PETROLEUM HYDROCARBONS AND VOCS
Regulatory Screening Levels - Protection of Human Health
EPA-RSLi
Date Sampled
Depth
(feet bgs)Sample ID
DTSC-SLi
SFBRWQCB-ESLi
Petroleum Hydrocarbons
(mg/kg)
VOCs
(ug/kg)
Antimony Arsenic Barium Beryllium Chromium Cobalt Copper Lead Mercury Molybdenum Nickel Silver Vanadium Zinc
4/21/25 0.51 J 0.60 J 118 0.37 J 81 7.6 22 11 ND<0.1 1.4 12 0.35 J 64 51
STLC (mg/L)4.2
4/21/25 1.3 J ND<2 133 0.30 J 170 6.0 20 8.6 ND<0.1 1.6 9.4 0.33 J 42 74
STLC (mg/L)1.0
TCLP (mg/L)ND<0.5
SB-32-5 5 4/23/25 ND<2 0.74 J 80 0.30 J 21 5.7 13 4.0 ND<0.1 0.30 J 10 ND<1 39 37
SB-32-15 15 4/23/25 0.68 J 3.1 74 0.52 J 14 11 22 15 ND<0.1 0.36 J 14 ND<1 41 63
SB-33-5 5 4/22/25 ND<2 0.56 J 75 0.47 J 11 8.6 11 5.8 ND<0.1 ND<1 10 ND<1 40 37
SB-33-15 15 4/22/25 ND<2 6.1 41 0.32 J 13 7.4 14 6.3 ND<0.1 0.35 J 13 ND<1 26 36
SB-34-5 5 4/21/25 ND<2 ND<2 225 ND<1 8.9 9.2 8.8 8.3 ND<0.1 ND<1 7.9 ND<1 42 64
SB-34-15 15 4/21/25 ND<2 ND<2 139 ND<1 13 7.1 18 6.9 ND<0.1 1.2 14 ND<1 34 49
SB-35-5 5 4/22/25 ND<2 ND<2 111 0.45 J 14 8.7 17 11 ND<0.1 0.37 J 11 ND<1 42 53
SB-35-15 15 4/22/25 ND<2 ND<2 97 0.36 J 13 8.5 17 6.7 0.17 ND<1 12 ND<1 42 153
SB-36-5 5 4/23/25 ND<2 ND<2 113 0.48 J 10 9.3 11 2.8 ND<0.1 0.13 J 9.2 ND<1 47 35
SB-36-15 15 4/23/25 ND<2 2.3 84 0.38 J 9.3 8.8 13 8.3 ND<0.1 ND<1 11 ND<1 40 48
SB-37-5 5 4/22/25 ND<2 5.0 48 0.28 J 10 6.6 16 14 ND<0.1 0.25 J 10 0.13 J 28 58
SB-37-15 15 4/22/25 ND<2 6.3 37 0.34 J 9.0 6.5 12 11 ND<0.1 ND<1 12 ND<1 27 47
SB-38-5 5 4/22/25 ND<2 9.0 71 0.41 J 14 8.3 19 29 ND<0.1 0.67 J 12 ND<1 36 75
SB-38-15 15 4/22/25 0.63 J 2.1 88 0.38 J 19 8.4 22 33 ND<0.1 0.70 J 14 0.19 J 40 63
SB-39-5 5 4/23/25 ND<2 ND<2 113 0.45 J 10 10 11 2.7 ND<0.1 0.16 J 9.0 ND<1 52 39
SB-39-15 15 4/23/25 ND<2 ND<2 134 0.42 J 8.4 11 12 2.0 ND<0.1 ND<1 8.2 ND<1 52 48
NE 0.36 NE 230 NE NE NE 500 4.4 NE 11,000 NE NE NE
470 3.0 220,000 2,300 NE 350 47,000 800 30 5,800 17,000 5,800 5,800 350,000
50 0.31 3,019 27 NE 28 14,158 160 44 1,770 86 1,770 466 106,182
NA 12 NA NA NA NA NA NA NA NA NA NA NA NA
Notes:
Sample ID - Sample identification.
bgs - Below ground surface.
Metals analyzed using U.S. Environmental Protection Agency (EPA) Method 6010B and reported in milligrams per kilogram (mg/kg). Mercury was analyzed using U.S. EPA Method 7471A and reported in mg/kg.
J - Detected but below the Practical Quantitation Limit; therefore, result is an estimated concentration.
ND - Not detected st or above laboratory reporting limit listed.
STLC - Soluble Threshold Limit Concentration analyzed using U.S EPA Method 6010B and reported in milligrams per liter (mg/L).
DTSC-SLi - California Department of Toxic Substance Control (DTSC), Human and Ecological Risk Office (HERO) Note 3, modified soil screening levels for commercial/industrial land use (SLi), revised in May 2022.
EPA-RSLi - U.S. EPA Regional Screening Level for soil for commercial/industrial land use (RSLi), updated in November 2023.
SFBRWQCB-ESLi - San Francisco Bay Regional Water Quality Control Board (SFBRWQCB), Environmental Screening Levels (ESLs) Workbook, for direct exposure human health risk level for commercial/industrial soil, dated 2019 Rev. 2
NE - Not established.
NA - Not applicable.
Bolded and highlighted data in light blue indicate concentrations exceed regulatory screening levels.
15
Arsenic background level as published in HERO Note 11, dated December 2020.
ARSENIC BACKGROUND
Regulatory Screening Levels - Protection of Human Health
TABLE 2 - LABORATORY RESULTS OF SOIL SAMPLING - METALS
Sample ID
Depth
(feet bgs)Date Sampled
Metals
(mg/kg)
SB-31-5 5
DTSC-SLi
EPA-RSLi
SFBRWQCB-ESLi
SB-31-15
1,1,1-Trichloroethane 1,1-Dichloroethene
2-Butanone
(MEK)Acetone Benzene
Tert-Butyl
Alcohol (TBA)
Tetrachloroethene
(PCE)
Trichlorofluoromethane
(FC-11)
Trichlorotrifluoroethane
(Freon 113)
SB-31-5 5 4/30/25 0.0 ND<15 ND<25 ND<200 ND<1,000 ND<25 ND<150 ND<25 15 ND<25
SB-31-15 15 4/30/25 0.0 ND<15 ND<25 ND<200 ND<1,000 ND<25 ND<150 ND<25 ND<15 29
SB-32-5 5 4/30/25 0.0 ND<15 ND<25 82 J 369 J 50 ND<150 ND<25 ND<15 37
SB-32-15 15 4/30/25 0.0 ND<15 ND<25 ND<200 ND<1,000 48 ND<150 ND<25 45 ND<25
SB-33-5 5 4/30/25 0.0 ND<15 ND<25 ND<200 ND<1,000 ND<25 ND<150 ND<25 ND<15 ND<25
SB-33-15 15 4/30/25 0.0 ND<15 ND<25 ND<200 ND<1,000 ND<25 ND<150 ND<25 11 J ND<25
SB-34-5 5 4/30/25 0.0 ND<15 ND<25 ND<200 ND<1,000 30 ND<150 ND<25 21 ND<25
SB-34-15 15 4/30/25 0.0 ND<15 ND<25 ND<200 ND<1,000 24 J ND<150 ND<25 15 ND<25
SB-35-5 5 5/1/25 0.0 ND<15 ND<25 ND<200 ND<1,000 ND<25 ND<150 ND<25 ND<15 ND<25
SB-35-15 15 5/1/25 0.0 ND<15 ND<25 ND<200 143 J 22 J 51 J ND<25 23 ND<25
SB-36-5 5 4/30/25 0.0 ND<15 ND<25 ND<200 ND<1,000 ND<25 ND<150 ND<25 ND<15 ND<25
SB-36-15 15 4/30/25 0.0 ND<15 ND<25 ND<200 ND<1,000 ND<25 ND<150 ND<25 ND<15 ND<25
SB-37-5 5 4/30/25 NM NS NS NS NS NS NS NS NS NS
SB-37-15 15 4/30/25 0.0 ND<15 ND<25 ND<200 ND<1,000 ND<25 ND<150 19 J 13 J ND<25
SB-38-5 5 4/30/25 0.0 ND<15 ND<25 ND<200 ND<1,000 ND<25 ND<150 ND<25 ND<15 ND<25
SB-38-15 15 4/30/25 0.0 ND<15 ND<25 ND<200 ND<1,000 ND<25 ND<150 ND<25 ND<15 ND<25
SB-39-5 5 4/30/25 0.0 ND<15 ND<25 ND<200 ND<1,000 24 J ND<150 ND<25 ND<15 ND<25
SB-39-5-Rep 5 4/30/25 --ND<15 ND<25 ND<200 ND<1,000 22 J ND<150 ND<25 ND<15 ND<25
SB-39-15 15 4/30/25 0.0 ND<15 ND<25 ND<200 ND<1,000 ND<25 ND<150 ND<25 ND<15 ND<25
NE 146,667 10,333 NE NE 14 NE 67 176,667 NE
NE 733,333 567 733,333 NE 53 733,333 1,567 NE 5,200
NE 146,000 10,220 730,000 4,526,000 14 NE 67 NE NE
Notes:
Sample ID - Sample Identification.
bgs - Below ground surface.
LEL - Lower explosive limit.
J - Detected but below the Practical Quantitation Limit; therefore, result is an estimated value.
ug/m3 - micrograms per cubic meter.
NM - Not measured.
ND - Not detected at or above the laboratory reporting limit(s) listed.
NS - Not sampled.
"--" - Not analyzed.
NE - Not established.
Bolded and highlighted data in light blue indicate concentrations exceed regulatory screening levels for industrial land use.
DTSC-SLi - California Department of Toxic Substance Control (DTSC), Human and Ecological Risk Office (HERO) Note 3, modified soil screening levels for commercial/industrial land use (SLi), revised in May 2022.
EPA-RSLi
SFBRWQCB-ESLi
DTSC-SLi
SFBRWQCB-ESLi - San Francisco Bay Regional Water Quality Control Board (SFBRWQCB), Environmental Screening Levels (ESLs) Workbook, for direct exposure human health risk level for commercial/industrial soil, dated 2019 Rev. 2
EPA-RSLi - U.S. EPA Regional Screening Level for soil for commercial/industrial land use (RSLi), updated in November 2024.
VOCs - Volatile organic compounds analyzed using U.S Environmental Protection Agency (EPA ) Method 8260B and reported in micrograms per cubic meter (ug/m3).
TABLE 3 - LABORATORY RESULTS OF SOIL VAPOR SAMPLING
Regulatory Screening Levels - Protection of Human Health
Sample ID Date Sampled
Depth
(feet bgs)
VOCs
(ug/m3)
Methane (%LEL)
9882 ALMOND AVENUE
FONTANA, CALIFORNIA
FIGURE 1
71
S
B
A
-
S
L
.
d
w
g
APPROXIMATE SCALE IN FEET
0 1,000 2,000
SITE VICINITY MAP
Reference:
US.G.S. 7.5-Minute Topographic Map,
Fontana & Guasti, 2018.
SITE
SB-31
15
SB-32
45
SB-34
60
SB-35
60
SB-33
15
SB-36
15
SB-39
15
SB-38
15
SB-37
45
SAN BERNADINO AVENUE
BA
N
A
N
A
A
V
E
N
U
E
CA
L
A
B
A
S
H
A
V
E
N
U
E
AL
M
O
N
D
A
V
E
N
U
E
CH
E
R
R
Y
A
V
E
N
U
E
FORMER
GRAVEL PIT
71SBA-ST.dwgFILE NAME:
DRAWN BY:
CHECKED BY:
DATE:
FIGURE:
11/2025
2SAMPLE LOCATION MAP
9882 ALMOND AVENUE
FONTANA, CALIFORNIA
BCD
APPROXIMATE SCALE IN FEET
0 280 560
LEGEND:
Soil Vapor Probe at 5ft & 15ft & Soil Samples at 5ft, 15ft, 30ft, 45ft, & 60ftSB-31
211 W. Avenida Cordoba, Suite 200 San Clemente, CA 92672 tel 949/361/3902 fax 949/361/3697
100392004
ATTACHMENT A
Laboratory Reports
May 13, 2025
Case Narrative
Client: Orion Environmental, Inc.
Project: HMC – Fontana / P.O. # 71 SBA
Report No.: 2504192
Eighteen soil samples and one duplicate were received by a Positive Lab Service representative
on April 25, 2025. The samples were collected on April 24, 2025, and were analyzed per
submitted Chain of Custodies. The temperature of the cooler was 2.6°C upon receipt.
The holding time and analytical acceptance criteria were met for the above-mentioned sample(s),
with the following exception(s).
VOCs
Continuing Calibration Verification (04/28/25 AM): The %D for Carbon disulfide (-23.0%) was
below the +/- 20% acceptance range, with an average %D of 8.64% for the method target
analytes.
SVOCs -SIM
Initial Calibration (05/03/25 GCMS#7): The %RSD for Acenaphthylene (16.4%) in the ICAL
were above the acceptance level of 15%, with an average %RSD of 10.6% for the method target
analytes. The linearity conditions for multi-analyte methods were met as specified in EPA
Method 8000.
1
May 01, 2025
Case Narrative
Client: Orion Environmental, Inc.
Project: HMC – Fontana / P.O. # 71 SBA
Report No.: 2504142
Twenty-two soil samples were received by a Positive Lab Service representative on April 21,
2025. The samples were collected on April 21, 2025, and were analyzed for TPH (EPA 8015B),
VOCs (EPA 8260B), and Metals (EPA 6010B/7471A) per submitted Chain of Custodies. The
cooler temperatures were 1.5°C and 1.6°C upon receipt.
The holding time and analytical acceptance criteria were met for the above-mentioned sample(s),
with the following exception(s).
VOCs
Continuing Calibration Verification (04/22/25 AM) – The %D for Dichlorodifluoromethane (-
21.1%) was below the +/- 20% acceptance range, with an average %D of 8.04% for the method
target analytes.
May 08, 2025
Case Narrative
Client: Orion Environmental, Inc.
Project: HMC – Fontana / P.O. # 71 SBA
Report No.: 2504164
Twenty-two soil samples were received by a Positive Lab Service representative on April 23,
2025. The samples were collected on April 21 and 22, 2025, and were analyzed for TPH (EPA
8015B), VOCs (EPA 8260B), and Metals (EPA 6010B/7471A) per submitted Chain of
Custodies. The cooler temperatures were 2.1°C and 2.8°C upon receipt.
The holding time and analytical acceptance criteria were met for the above-mentioned sample(s),
with the following exception(s).
VOCs
Continuing Calibration Verification (04/24/25 AM) – The %D for Dichlorodifluoromethane (-
27.0%) was below the +/- 20% acceptance range, with an average %D of 8.05% for the method
target analytes. For sample 02.
Continuing Calibration Verification (04/24/25 PM) – The %D for Dichlorodifluoromethane (-
38.8%), Carbon disulfide (-27.7%), 2,2-Dichloropropane (-21.1%) and Dibromochloromethane
(-22.3%) were below the +/- 20% acceptance range, with an average %D of 11.60% for the
method target analytes. For sample 01.
Continuing Calibration Verification (04/25/25 PM) – The %D for Dichlorodifluoromethane (-
20.7%) and Carbon disulfide (-25.0%) were below the +/- 20% acceptance range, with an
average %D of 10.49% for the method target analytes. For samples 03 – 23.
Exceedance Report
Reported: 04/28/2025
The analytes listed in this report exceed one or more of the set flag levels
Project:
Project Number:
Project Manager:Long Beach, CA 90806
2955 Redondo Beach Ave. 75682
HMC - Fontana / P.O. # 71 SBA
Kirstin Gundel
Orion Environmental, Inc.
Report Number (Matrix):
Analyte Result
Reporting
Limit Units
STLC
Flag Level
TCLP Flag
Level
Sample Name: SC-1
Qual
2504164-01 (Soil)
Chromium 61.3 mg/kg 50 100
Report Number (Matrix):
Analyte Result
Reporting
Limit Units
STLC
Flag Level
TCLP Flag
Level
Sample Name: SB-31-5
Qual
2504164-22 (Soil)
Chromium 81.1 mg/kg 50 100
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