HomeMy WebLinkAbouthecate_ortega_bess_substation_geotech_addendum_20210614 Stantec Consulting Services Inc.
735 East Carnegie Drive,Suite 280
San Bernardino,CA 92408
Tel: (909) 335-6116
Stantec Fax: (909) 335-6120
June 14, 2021
Mr. Gabriel Wapner
Hecate Grid LLC
621 Randolph Street
Chicago, Illinois 60661
Reference: GEOTECHNICAL REPORT ADDENDUM
Ortega Battery Energy Storage System Project
Lake Elsinore, Riverside County, California
Stantec Project No. 185805133
Dear Mr. Wapner,
This letter presents a Geotechnical Report Addendum to the Geotechnical Investigation Report
prepared by Stantec dated April 29, 2021.
SECTION 2.4 - SOIL ELECTRICAL RESISTIVITY TESTING
A soil electrical resistivity study was conducted by Atlas Technical Consultants (ATC),which included
collection of electrical resistivity data at the site, compilation and analysis of the data
collected, and preparation of the data report as included in Attachment 1 of this
addendum letter. Specifically, ATC conducted two crossing, nearly orthogonal resistivity
soundings at five locations (R-1 through R-5) onsite for a total of ten lines. The roughly northeast
to southwest trending lines are given an "a" designation (e.g., R-1 a) and the roughly northwest
to southeast lines are given a "b" designation (e.g., R-lb). In Attachment 1, Figure 2 illustrates
the approximate sounding locations, and Figure 3 illustrates the conditions in the study areas. A
summary of the findings is provided in Revised Section 7.3.
The data were collected in general accordance with ASTM G57 using an Advanced Geosciences,
Inc. (AGI) MiniSting earth resistivity meter and four steel electrodes in a Wenner configuration. Soil
resistance measurements were collected at electrode spacing distances of 2.5, 5, 10, 20, and 50
feet, along the two lines with the middle of each sounding generally located at a common center
point. The stainless-steel electrodes were hammered into place and the soils surrounding the
electrodes were moistened with saline water where necessary.
REVISED SECTION 3.0 - LABORATORY TESTING
The following laboratory tests were performed in general accordance with ASTM and California
Test procedures:
Table 1. Summary of Laboratory Tests
Type of Test ASTM Designation Number
Performed
Sieve Analysis ASTM D422 and ASTM C136 7
Design with community in mind
® Stantec
June 14, 2021
Page 2 of 3
Reference: Geotechnical Report Addendum-Ortega Battery Energy Storage System Project
Type of Test ASTM Designation Number
Performed
Direct Shear ASTM D3080 2
Maximum Dry Density and
Optimum Moisture Content ASTM D1557 1
(Modified Proctor)
Thermal Conductivity by
Thermal Needle Probe ASTM D5334 2
Procedure
Chemical Tests for Corrosion CA DOT test methods 2
Potential
The laboratory test results for Thermal Resistivity are presented in Attachment 2.
REVISED SECTION 7.3 - CORROSION POTENTIAL
Two samples of the onsite soils were tested to provide a preliminary indication of the corrosion
potential of the onsite soils. The test results are presented in Appendix B of Stantec's Geotechnical
Investigation Report (Stantec, 2021). A brief discussion of the corrosion test results is provided in the
following text.
• The samples tested had a soluble sulfate concentration ranging from 40 to 345 parts per
million (ppm),which indicates the samples have a low sulfate corrosion potential relative
to concrete. It should be noted that soluble sulfate in the irrigation water supply, and/or
the use of fertilizer may cause the sulfate content in the surficial soils to increase with
time. This may result in a higher sulfate exposure than that indicated by the test results
reported herein. Studies have shown that the use of improved cements in the concrete,
and a low water-cement ratio will improve the resistance of the concrete to sulfate
exposure.
• The samples tested had a chloride concentration ranging from 23 ppm to 35 ppm,which
indicates the sample has a negligible chloride corrosion potential relative to metal.
• The samples tested had a saturated resistivity ranging from 1,378 to 2,408 ohm-cm,which
indicates the samples are severely corrosive.
• The sample tested had a pH ranging from 7.6 to 7.7, which indicates the samples are
slightly alkaline.
Field Wenner four-point resistivity testing was conducted by ATC at the Site. The results of the field
resistivity testing indicate variable corrosion potential in the subsurface profile (Attachment 1). In
Design with community in mind
® Stantec
June 14, 2021
Page 3 of 3
Reference: Geotechnical Report Addendum-Ortega Battery Energy Storage System Project
general, the resistivity decreases (higher corrosion potential) with increasing water content and
salt concentration. In dry and environments like that of the Site, seasonal low moisture content in
near surface soils and evapotranspiration are important factors influencing corrosion potential of
the soil profile. The field data (Figures 4a and 4b in Attachment 1) indicate relatively moderate to
high (1,889 to 12,643 ohm-cm) and apparent mild to severe corrosion potential to ferrous metal in
the near surface materials to a depth of at least 20 feet (note: the depth of the measured
average resistivity in the soil profile is assumed to be equivalent to the probe spacing). Laboratory
testing on saturated samples showed similar corrosion potential.
Caltrans currently considers a site to be corrosive to foundation elements if one or more of the
following conditions exist: Chloride concentration is greater than or equal to 500 ppm, sulfate
concentration is greater than or equal to 1,500 ppm, or the pH is 5.5 or less (Caltrans, 2012).
Proposed import fill materials should be tested to evaluate their corrosion potential prior to being
imported to the site.
If you have any questions or need additional information, please contact us.
Respectfully submitted,
Stantec Consulting Services Inc.
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Jaret is * E ..3131123 * Evan Hsiao, P , GE
Principal Enginee s CIVIC. �Q Principal, Se for Geotec7alineer
Phone: (909) 335-61 16 ext. 82 T�TFOFCAUF � Phone: (949) 923-6000
Jaret.Fischer@stantec.com Evan.Hsiao@stantec.com
ATTACHMENTS
Attachment 1 -Geophysical Evaluation- Electrical Resistivity
Attachment 2-Additional Laboratory Test Results
REFERENCES
Stantec Consulting Services Inc,April 29, 2021, Geotechnical Investigation Report, Proposed Hecate
Ortega BESS and Substation, Lake Elsinore, Riverside County, California, Stantec Project No.
185805133.
Design with community in mind
® Sta me c
ATTACHMENT 1
GEOPHYSICAL EVALUATION — ELECTRICAL
RESISTIVITY
Design with community in mind
6280 Riverdale Street
San Diego, CA 92120
(877)215-4321 1 oneatlas.com
June 2, 2021
Atlas No. 121188SWG
Report No. 1
MR. JARET FISCHER, PE
STANTEC
735 EAST CARNEGIE DRIVE, SUITE 280
SAN BERNARDINO, CALIFORNIA 92408
Subject: Geophysical Evaluation — Electrical Resistivity
Ortega Grid
Lake Elsinore, California
Dear Mr. Fischer:
In accordance with your authorization, Atlas has performed a geophysical evaluation pertaining
to the Ortega Grid project located in Lake Elsinore, California (Figure 1). The purpose of our
evaluation was to collect in-situ electrical resistivity measurements. Our services were conducted
on May 17, 2021. This report presents our methodology, equipment used, analysis, and results.
Our scope of services for the project included collection of electrical resistivity data at the site,
compilation of the data collected, and preparation of this data report. Specifically, we conducted
five soundings at the project site (R-1 through R-5). The soundings consisted of two orthogonal
test lines designated R-1 a and R-1 b through R-5a and R-5b at locations and electrode spacings
specified by you. Figure 2 illustrates the approximate sounding locations, and Figures 3a and 3b
depict the general site conditions in the study area.
The data was collected in general accordance with ASTM G57 using an Advanced Geosciences,
Inc. (AGI) SuperSting R8 earth resistivity meter and four steel electrodes in a Wenner
configuration. For each line, soil resistance measurements were collected at electrode spacings
of 2, 4, 6, 8, 12, 20, 30 and 50 feet along the line. Stainless steel electrodes were hammered in
place at your specified locations and the soils surrounding the electrodes were moistened with
saline water (potable water with added table salt) to help overcome soil contact resistance.
The results of the electrical resistivity study are presented in Figures 4a and 4b. The
measurements collected along each of the two orthogonal test lines are generally consistent (with
some slight variations) indicating that the subsurface conditions are fairly uniform with respect to
apparent resistivity. It should be noted that two of the sounding locations, R-2 and R-4, displayed
inconsistent values between the orthogonal lines at the shortest spacing. The cause of these
variations is not known; however, could be the result of relatively shallow geologic changes in soil
material properties, presence of relatively shallow small diameter animal burrows or tunnels, or
the presence of fill materials.
Page 11
MEN I
The field services and geophysical analyses presented in this report have been conducted in
general accordance with current practice and the standard of care exercised by consultants
performing similar tasks in the project area. No warranty, express or implied, is made regarding
the conclusions presented in this report. Please also note that our evaluation was limited to
measuring in-situ apparent soil resistivity at five sounding locations selected by your office.
Atlas should be contacted if the reader has questions regarding the content, interpretations
presented, or completeness of this document. This report is intended exclusively for use by the
client. Any use or reuse of this report by parties other than the client is undertaken at said parties'
sole risk.
We appreciate the opportunity to be of service on this project. Should you have any questions
related to this report, please contact the undersigned at your convenience.
Respectfully submitted,
Atlas Technical Consultants LLC
fo� lwv�p�
Q
Paul Neuberger Mark Edwards, R.G. (Arizona)
Senior Staff Geophysicist Q�oFV_-ssio/vj Principal Geologist/Geophysicist
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No. 1043
Exp.1/31/2022 y
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Patrick F. Lehrmann, P.G., P.Gp.
Principal Geologist/Geophysicist
PN:MDE:PFL:ds
Attachments: Figure 1 —Site Location Map
Figure 2— Line Location Map
Figure 3a—Site Photographs (R-1 a through R-3b)
Figure 3b—Site Photographs (R-4a through R-5b)
Figure 4a— Electrical Resistivity Results (R-1a through R-3b)
Figure 4b— Electrical Resistivity Results (R-4a through R-5b)
Distribution: Jaret Fischer at Jaret.Fischer@Stantec.com
Atlas No. 121188SWG
Report No. 1
Page 12
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SITE LOCATION MAP Lake Elsinore, California -r ��-
Figure 1
Project No.: 121188SWG I Date:05/21
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low
Ortega Grid
SITE PHOTOGRAPHS Lake Elsinore, California �—
(R-1a through R-3b) Figure 3a
Project No.: 121188SWG Date:05/21
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PHOTOGRAPHS
SITE
- Elsinore, California
• • •
Project :: Date 05/21
Line No. Spacing Current Resistance Error Apparent Resistivity
Orientation (ft) (mA) (Ohms) N (ohm-cm) (ohm-ft)
R-1 a 2 86.9 7.672 0.1 2938.55 96.41
(SW-NE) 4 1202.0 2.713 0.0 2078.28 68.19
6 1183.0 1.853 0.0 2129,22 69.86
8 871.1 1.233 0.0 1889.07 61.98
12 1091.0 0.929 0.0 2135.20 70.05
20 1138.0 0.626 0.0 2399.25 78.72
30 521.6 0.522 0.0 2996.77 98.32
50 845.4 0.540 0.0 5172.72 169.71
R-1 b 2 58.4 10.610 0.1 4063.87 133.33
(SE-NW) 4 803.0 2.515 0.0 1926.60 63.21
6 968.2 1.909 0.0 2193.57 71.97
8 913.2 1.284 0.0 1967.20 64.54
12 882.7 0.950 0.0 2183.69 71.64
20 918.4 0.620 0.0 2373.59 77.87
30 1213.0 0.471 0.0 2706.06 88.78
50 937.9 0.357 0.1 3415.60 112.06
R-2a 2 97.4 19.320 0.0 7400.00 242.78
(SW-NE) 4 51.1 6.124 0.0 4691.26 153.91
6 961.0 3.153 0.0 3623.01 118.87
8 745.5 2.713 0.0 4156.56 136.37
12 797.6 1.670 0.0 3837.89 125.91
20 812.6 1.038 1 0.0 3975.78 1 130.44
30 913.2 0.717 0.1 4118.26 135.11
50 847.0 0.601 0.1 5751.09 188.68
R-2b 2 26.1 6.735 0.0 2579.66 84.63
(SE-NW) 4 20.6 5.086 0.0 3896.11 127.83
6 25.7 3.108 0.0 3571.30 117.17
8 19.1 2.364 0.0 3621.86 118.83
12 19.3 1.447 0.0 3325.40 109.10
20 19.4 1.197 0.0 4584.78 150.42
30 1403.0 0.775 0.0 4453.21 146.10
50 1067.0 0.528 0.1 5052.07 165.75
R-3a 2 38.1 16.890 0.0 6469.25 212.25
(SW-NE) 4 750.3 4.768 0.0 3652.50 119.83
6 883.0 2.907 0.0 3340.34 109.59
8 719.8 2.045 0.0 3133.13 102.79
12 709.7 1.222 0.0 2808.32 92.14
20 868.6 0.714 0.0 2735.16 89.74
30 927.1 0.626 0.0 3596.01 117.98
50 898.7 0.532 0.1 5092.29 167.07
R-3b 2 35.8 17.620 0.1 6748.86 221.42
(SE-NW) 4 606.3 4.635 0.0 3550.62 116.49
6 531.9 3.089 0.0 3549.47 116.45
8 554.4 2.040 0.0 3125.46 102.54
12 648.6 1.525 0.0 3504.66 114.98
20 1 750.9 1 1.003 1 0.0 1 3841.72 126.04
30 710.8 0.677 0.0 3891.32 127.67
50 873.0 0.531 0.0 5088.46 166.94
ELECTRICAL RESISTIVITY Ortega Grid
RESULTS Lake Elsinore, California --r ��--
(R-1a through R-3b) Figure 4a
Project No.: 121188SWG Date: 05/21
Line No. Spacing Current Resistance Error Apparent Resistivity
Orientation (ft) (mA) (Ohms) (%) (ohm-cm) (ohm-ft)
R-4a 2 58.3 33.010 0.0 12643.58 414.82
(SW-NE) 4 656.5 3.808 0.0 2917.10 95.71
6 757.3 2.220 0.0 2550.93 83.69
8 749.9 1.516 0.0 2322.65 76.20
12 801 A 1.161 0.0 2668.14 87.54
20 625.6 0.759 0.0 2905.23 95.32
30 690.5 0.470 0.0 2697.44 88.50
50 830.4 0.351 0.1 3359.11 110.21
R-4b 2 61.8 15.710 0.0 6017.29 197.42
(SE-NW) 4 681.0 3.183 0.0 2438.32 80.00
6 789.8 1.992 0.0 2288.94 75.10
8 810.6 1.446 0.0 2215.40 72.68
12 803.9 1.095 0.0 2516.46 82.56
20 842.0 0.742 0.0 2842.03 93.24
30 739.9 0.537 0.0 3086.40 101.26
50 676.0 0.370 0.0 3544.87 116.30
R-5a 2 99.0 12.410 0.0 4753.31 155.95
(SW-NE) 4 83.7 4.221 0.0 3233.48 106.09
6 1128.0 2.645 0.0 3039.28 99.71
8 893.7 2.102 0.0 3220.45 105.66
12 996.0 1.439 0.0 3307.02 108.50
20 1189.0 0.968 0.0 3708.81 121.68
30 887.8 0.627 0.0 3601.75 118.17
50 1036.0 0.428 0.0 4093.55 134.30
R-5b 2 81.4 10.010 0.0 3834.06 125.79
(SE-NW) 4 89.0 4.305 0.0 3297.83 108.20
6 856.1 2.536 0.0 2914.04 95.60
8 326.4 1.858 0.0 2846.62 93.39
12 1032.0 1.158 0.0 2661.24 87.31
20 1030.0 0.950 0.0 3638.33 119.37
30 1081.0 0.745 0.0 4279.13 140.39
50 827.6 0.404 0.1 3868.53 126.92
ELECTRICAL RESISTIVITY Ortega Grid
RESULTS Lake Elsinore, California
(R-4a through R-5b) Figure 4b
Project No.: 121188SWG Date:05/21
® Sta me c
ATTACHMENT 2
ADDITIONAL LABORATORY TEST RESULTS
Design with community in mind
MATERIALS PAGE#1 PRINT DATE
6/9/2021
C:\Users\roeskej\Box\Reports\Boise\2019
Reports\800-999\131909861-Miscellaneous
TESTING & THERMAL RESISTIVITY Laboratory Services-Stantec Consulting\1 Hecate
INSPECTION San Jacinto Ortega BESS\Hecate Ortega
BESS\B2\B190986L-060921=L=S-
B2The rnra 1210517.d ocx
❑ Environmental Services ❑ Geotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections
Jaret Fischer Phone: 909-255-8209
Stantec Consulting Services, Inc.-San Bernadino Fax:
735 East Carnegie Drive, Suite 280 Other: E-REPORTS ONLY
San Bernadino, CA 92408
Project: Miscellaneous Laboratory Services
Project Manager: Jesse Roeske
Lab Technician: A. Hanle
Test Date: June 9, 2021
As requested MTI has performed corrosion testing on the sample referenced below. The testing was performed
in accordance with current standards indicated below. The results obtained in our laboratory were as follows:
Source: Sample was collected and delivered by the client.Test results apply to the sample as received.
Date Obtained: May 2021
Sample ID: 21-0517 B190986L ,Hecate Ortega BESS,B2
Moisture Content, Thermal Resistivity °C•cm/W
Percent of Dry Mass
6 89.1
4 105.3
2 123.0
0 1 276.0
Samples were compacted to approximately 90% of the dry density of the proctor value and at varying
percentages of the optimum moisture.
If there are questions concerning this report (B190986L-060921=L=S-B2Thermal210517), please contact the
project manager at(208) 376-4748.
Respectfully submitted,
MATERIALS TESTING & INSPECTION, INC.
d-P-0-
Jesse Roeske
Boise Laboratory Coordinator
2791 S Victory View Way•Boise,ID 83709•(208)376-4748• Fax(208)322-6515
www.mti-id.com•mti(a).mti-id.com Revised February 2011
Hecate Ortega, B2
300
276
250
200
E
V
iF
U
a) 150
123
0
0 105.3
t
100 89.1
50
0
0 1 2 3 4 5 6 7
Moisture Content Based on Dry Mass(%)
MATERIALS PAGE#1 PRINT DATE
6/9/2021
C:\Users\roeskej\Box\Reports\Boise\2019
Reports\800-999\131909861-Miscellaneous
TESTING & THERMAL RESISTIVITY Laboratory Services-Stantec Consulting\1 Hecate
INSPECTION San Jacinto Ortega BESS\Hecate Ortega
BESS\B4\B190986L-060921=L=S-
B4T h e rnr a 1210518.d o cx
❑ Environmental Services ❑ Geotechnical Engineering ❑ Construction Materials Testing ❑ Special Inspections
Jaret Fischer Phone: 909-255-8209
Stantec Consulting Services, Inc.-San Bernadino Fax:
735 East Carnegie Drive, Suite 280 Other: E-REPORTS ONLY
San Bernadino, CA 92408
Project: Miscellaneous Laboratory Services
Project Manager: Jesse Roeske
Lab Technician: A. Hanle
Test Date: June 9, 2021
As requested MTI has performed corrosion testing on the sample referenced below. The testing was performed
in accordance with current standards indicated below. The results obtained in our laboratory were as follows:
Source: Sample was collected and delivered by the client.Test results apply to the sample as received.
Date Obtained: May 2021
Sample ID: 21-0518 B190986L ,Hecate Ortega BESS,B4
Moisture Content, Thermal Resistivity °C•cm/W
Percent of Dry Mass
6 79.1
4 88.4
2 160.0
0 1 537.1
Samples were compacted to approximately 90% of the dry density of the proctor value and at varying
percentages of the optimum moisture.
If there are questions concerning this report (B190986L-060921=L=S-B4Thermal210518), please contact the
project manager at(208) 376-4748.
Respectfully submitted,
MATERIALS TESTING & INSPECTION, INC.
d-P-0-
Jesse Roeske
Boise Laboratory Coordinator
2791 S Victory View Way•Boise,ID 83709•(208)376-4748• Fax(208)322-6515
www.mti-id.com•mti(a).mti-id.com Revised February 2011
Hecate Ortega, B4
600
537.1
500
400
E
u
c�
v 300
0
°C 200 160
100 I 88.4 79.1
0
0 1 2 3 4 5 6 7
Moisture Content Based on Dry Mass(%)