Loading...
HomeMy WebLinkAboutAppendix I - Excavation and Transportation CompletionEN G I N E E R S + GE O L O G I S T S + EN V I R O N M E N T A L S C I E N T I S T S EXCAVATION, TRANSPORTATION, AND DISPOSAL COMPLETION REPORT SOIL REMOVAL ACTIVITIES, CONIFER RIDGE PROPERTY 14.5 ACRES OF VACANT LAND SOUTH OF CONIFER COURT AND VILLAGE DRIVE, APN 0237-411-27-0000 CITY OF FONTANA, SAN BERNARDINO COUNTY, CALIFORNIA 92337 CONIFER COURT LLC January 3, 2025 J.N. 24-229 ENGINEERS + GEOLOGISTS + ENVIRONMENTAL SCIENTISTS Offices Strategically Positioned Throughout Southern California RIVERSIDE COUNTY OFFICE 40880 County Center Drive, Suite M, Temecula, CA 92591 T: 951.600.9271 F: 951.719.1499 For more information visit us online at www.petra-inc.com January 3, 2025 J.N. 24-229 CONIFER COURT LLC 500 Newport Center Drive, Suite 570 Newport Beach, California 92660 Attention: Mr. J. Rob Meserve Subject: Excavation, Transportation and Disposal Completion Report; Soil Removal Activities, Conifer Ridge Property, 14.5 Acres of Vacant Land South of Conifer Court and Village Drive, APN 0237-411-27-0000, City of Fontana, San Bernardino County, California 92337 Dear Mr. Meserve: Petra Geosciences, Inc. (Petra) presents this Excavation, Transportation, and Disposal Completion Report for Soil Removal Activities on the Conifer Ridge project, city of Fontana, San Bernardino County, California. All work summarized herein has been completed in general accordance with the scope and limitations set forth in our original proposal, 24-229P (dated May 17, 2024) and in Amendment No. 1 (dated August 21, 2024). This opportunity to be of service to you is sincerely appreciated. Please do not hesitate to call this office if you have questions pertaining to this report. Respectfully submitted, PETRA GEOSCIENCES, INC. ______________________________ Edward Lump Siamak Jafroudi, PhD Associate Geologist Senior Principal Engineer DRAFT DRAFT CONIFER COURT, LLC January 3, 2025 Conifer Ridge Project / Fontana J.N. 24-229 TABLE OF CONTENTS Page INTRODUCTION ......................................................................................................................................................... 1 Project Location ................................................................................................................................................. 1 Project Description ............................................................................................................................................. 1 Background Summary ........................................................................................................................................ 2 PROCEDURES FOR EXCAVATION, TRANSPORTATION, AND DISPOSAL ..................................................... 3 Excavation .......................................................................................................................................................... 3 Conformation Sampling ..................................................................................................................................... 4 CONCLUSIONS ........................................................................................................................................................... 9 Discussion .......................................................................................................................................................... 9 Transportation of Stockpiled Soil..................................................................................................................... 10 Bill-of-Lading .................................................................................................................................................. 11 Disposal Facility............................................................................................................................................... 11 Reporting and Field Oversight ......................................................................................................................... 11 Documentation ................................................................................................................................................. 11 LIMITATIONS ........................................................................................................................................................... 12 REFERENCES ............................................................................................................................................................ 13 ATTACHMENTS TABLE 1 – SUMMARY OF LEAD AND TOTAL CHROMIUM STLC RESULTS TABLE 2 – SUMMARY OF CAM TITLE 22 METALS (TTLC) – STOCKPILE SOIL TABLE 3 – SUMMARY OF TOTAL PETROLEUM HYDROCARBONS – STOCKPILE SOIL TABLE 4 – VOLATILE ORGANIC COMPOUNDS – STOCKPILE SOILS FIGURE 1 – SITE LOCATION MAP FIGURE 2 – EXCAVATION AND STOCKPILE LOCATION MAP, PHASE 1 FIGURE 3 – EXCAVATION AND STOCKPILE LOCATION MAP, PHASE 2 APPENDIX A – LABORATORY REPORTS AND CHAIN-OF-CUSTODY DOCUMENTS APPENDIX B – BILL-OF-LADING EXCAVATION, TRANSPORTATION, AND DISPOSAL COMPLETION REPORT SOIL REMOVAL ACTIVITIES, CONIFER RIDGE PROPERTY 14.5 ACRES OF VACANT LAND SOUTH OF CONIFER COURT AND VILLAGE DRIVE, APN 0237-411-27-0000 CITY OF FONTANA, SAN BERNARDINO COUNTY, CALIFORNIA 92337 INTRODUCTION Petra Geosciences, Inc. (Petra) is submitting this excavation, transportation, and disposal completion report to summarize excavation and transportation procedures, collection of stockpile characterization soil samples, and removal confirmation soil samples completed on August 22 and September 20, 2024. Our field sample collection was performer by Mr. Kurtis Morenz, Senior Staff Geologist and Mr. Edward Lump, with compilation performed by Mr. Edward Lump, Associate Geologist, and with oversight by Dr. Siamak Jafroudi, President and Principal Engineer. Project Location The subject property consists of an irregular-shaped 14.5-acre vacant site south of the intersection of Conifer Court and Village Drive in the city of Fontana, California. The subject property, situated east of Live Oak Avenue, is bounded by vacant land to the west (Southridge property), Village Drive on the north, an improved drainage channel on the east (Declez Channel), and an abandoned rock quarry on the south. Conceptual development plans provided to us denoted that the property will be developed as a self-storage facility (Allard Engineering, 2022). A site location map is included as Figure 1. Project Description The subject property consists of approximately 14.5-acres of vacant land that was historically developed as a rock quarry with railroad spur access. A gated entrance to the subject property is on the south side of Village Drive. The highly irregular surface of the subject property overall has been disturbed by historic quarry activities, which includes the (offsite) excavation of a high cut slope face and placement of a large rectangular-shaped stockpile of soil and rock on the northern portion of the site. The southwest and southeast property boundaries abut natural ascending slopes. The eastern portion of the subject property, beyond the large stockpile, appears to consist of fill overlying undisturbed alluvium deposited at the outlet of a natural drainage extending upslope into the Jurupa Mountains. Subsequent to mining activities, what appears to be a large volume of oversized rock/boulders and large concrete fragments have been dumped throughout the subject property; however, some of the over-sized boulders have been removed from the property. Existing elevation provided on Google Earth (2024) are on the order of approximately 945± to 990± feet above mean sea level (msl). DRAFT DRAFT CONIFER COURT, LLC January 3, 2025 Conifer Ridge Project / Fontana J.N. 24-229 Page 2 The surface of the subject property is currently void of most native vegetation. which previously covered the piles of rock and concrete scattered across the property. We understand that the eastern portion of the subject property, beyond the former quarry operation, is planned for open space. This area currently contains a few stockpiles of boulders and concrete. This area is void of vegetation in the stockpile areas, with dry native grasses in undisturbed areas. Background Summary Results of the Phase I Environmental Site Assessment and Limited Phase II Metals Soil Residue Survey by Petra (dated June 17, 2024) indicated areas of elevated Lead and Chromium soil residues had been delineated both vertically and horizontally along the former railroad spur alignment within the subject property. Elevated Total Threshold Limit Concentration (TTLC) and Soluble Threshold Limit Concentration (STLC) results for Lead soil residues, and to a lesser extent Chromium, were delineated in sample locations S-2, S-3, S-4, S-5, and S-17. An elevated TTLC lead concentration was reported in sample location S-3 at 1 foot. Elevated STLC concentrations were reported for soil samples S-17 at 0-1 foot and 2- foot. Additionally, elevated STLC levels of Lead were reported in sample S-2 at 1 foot, sample S-4 at 1 foot, and in sample S-5 at 1 foot. Laboratory test results from soil samples collected vertically below these sample depths and horizontally beyond in step-out locations were reported below the Department of Toxic Substances Control (DTSC) Residential Screening Levels (SLs), the San Francisco Bay Regional Water Quality Control Board (SFBRWQCB) Environmental Screening Levels (ESLs), and/or the USEPA Residential Regional Screening Levels (RSLs) for Lead and Chromium. In addition to soil analysis for Lead and Chromium, soil samples collected from the early phases of the Limited Phase II Metals Soil Residue Survey (Petra, 2024) were analyzed for other Title 22 Metals, Polycyclic Aromatic Hydrocarbons (PAHs), and Total Petroleum Hydrocarbons (TPHs). Laboratory results from these analyzes reported non-detect or very low to low laboratory results below the applicable DTSC, SFBRWQCB, and/or USEPA residential screening levels. The Limited Phase II sample locations are provided below in Figure A. DRAFT DRAFT CONIFER COURT, LLC January 3, 2025 Conifer Ridge Project / Fontana J.N. 24-229 Page 3 Figure A – Limited Phase II Sample Location Map (Petra, 2024) PROCEDURES FOR EXCAVATION, TRANSPORTATION, AND DISPOSAL Excavation As described in the Phase I Environmental Site Assessment and Limited Phase II Metals Soil Residue Survey (Petra, 2024), Recognized Environmental Conditions (RECs) were identified within the subject property associated with elevated Lead and Chromium concentrations reported in soil samples collected along the former railroad spur. Based upon laboratory results from soil samples collected from step-out test pits, the limits of elevated Lead and Chromium residues were determined. Using photography from drone flights by the client and photographs by Petra during the Phase II soil survey (Petra, 2024), the center of the five recommended remedial excavations, S-2, S-3, S-4, S-5, and S-17, were determined and marked in the field by the client. Petra was notified when the excavations were complete . A map showing the initial remedial excavation locations is provided in Figure 2. A summary of removal locations and depths is provided below. DRAFT DRAFT CONIFER COURT, LLC January 3, 2025 Conifer Ridge Project / Fontana J.N. 24-229 Page 4 • Removals extended to a depth of approximately 3 feet below the ground surface from 25 feet east of S-3/S-24 to 25 feet west of S-3/S-24. • Removals extended from 25 feet east of S-2 to 25 feet west of S-2 to a depth of approximately 1.5 feet below the existing ground surface. • Removals extended to a depth of approximately 1.5 feet below the ground surface from 25 feet east ofS-4 to 25 feet west of S-4. • Removals extended to a depth of approximately 1.5 feet below the ground surface from 25 feet east ofS-5 to 25 feet west of S-5. • Removals extended from a distance of 25 feet east of S-17 to 25 feet west of S-17 to a depth of approximately 3.5 feet. It is our understanding that the contractor (The Hillside Group, Inc.) provided a track-mounted excavator to conduct all excavation activities required to remove and stockpile the Lead and Chromium impacted soils. Additionally, scheduling and loading of export trucks and soil disposal was coordinated by the contractor. Based upon our field observations, the remedial excavations were slightly larger in dimension than what was recommended both vertically and horizontally due to oversize rock and sloughing. Conformation Sampling Removal Excavations Petra mobilized to the subject property on August 22, 2024, after excavations were complete, to collect soil removal verification samples and stockpile characterization samples from the five excavations. Five removal verification samples (RVS) were collected from randomly chosen sidewall and bottom locations from each excavation to verify that elevated Lead and Chromium soil residue concentrations had been removed. Overall, 25 soil samples (and 2 duplicates) were collected from the five remedial excavations. A map showing the estimated sample locations is provided on Figure 2. Based upon the laboratory Lead STLC results of soil samples collected from the removal excavations, additional removals were recommended to the S-3 excavation (bottom and west wall), S-5 excavation (south and west walls), and S-17 excavation (bottom, north, and east walls). Removal verification samples collected from S-2 and S-4 reported STLC levels below the 5.0 ug/L limit; therefore, no additional remedial removals were needed in the S-2 and S-4 excavations. On September 20, 2024, Petra mobilized to the subject property to collect additional soil removal verification samples from the additional removals in the three excavations (S-3, S-5, and S17). Additional removal excavations were complete upon our arrival. Samples were collected from the same area where DRAFT DRAFT CONIFER COURT, LLC January 3, 2025 Conifer Ridge Project / Fontana J.N. 24-229 Page 5 additional removals were completed. Two samples were collected from S3 (S3 RVS-3A, S3 RVS-5A, and duplicate); two samples were collected from S-5 ( S5 RVS-2A and S5 RVS-3a); and S-17 (S17 RVS-3A, S17 RVS-4A, and S17 RVS-5A). The limits of the additional excavations and verification sample locations is provided in Figure 3. Soil Stockpiles The DTSC Information Advisory Clean Import Fill Material Fact Sheet (dated October 2001) was reviewed for stockpile sample guidance. The recommended samples per volume of area stockpile is 1 sample per 250 cubic yards for a stockpile up to 1,000 cubic yards. On August 22, 2024, two soil samples were collected from each of the stockpiles associated with S-2, S-3, S-4 and S-5. Three samples were collected from the stockpile associated with S-17. Overall, Petra collected 11 samples (and 1 duplicate) from the stockpiles of soil generated for offsite disposal characterization . A map showing the initial sample locations is provided in Figure 2. Samples were collected directly from the stockpiles via a stainless-steel trowel and sterile gloved hand. Each stockpile sample was collected from at least two different locations in the stockpile. Each sample was immediately placed in a sterile glass jar (provided by the testing laboratory), sealed, properly labeled with sample date, time, location and depth, and immediately placed within a chilled cooler and transportation to Enviro-Chem, Inc. Laboratories the same day by Petra. On September 20, 2024, Petra mobilized to the subject property to collect additional soil removal stockpile characterization samples from additional removals to the three excavations (S-3, S-5, and S17). Two samples were collected from S-3 stockpile (S3 SSS-3 and S3 SSS-3 duplicate); two samples were collected from S-5 stockpile (S5 SSS-3 and S5 SSS-4); and one sample from S-17 stockpile (S17 SSS-4). The limits of the additional stockpiles and verification sample locations are provided in Figure 3. Laboratory Testing All samples were logged into a chain-of-custody (COC) form, signed by Petra, and by the laboratory representative. A copy of the laboratory reports and COC’s are provided in Appendix A. All analysis was completed by Enviro-Chem Laboratories, Inc., a California Environmental Laboratory Accreditation Program (ELAP) laboratory located in Pomona, California. DRAFT DRAFT CONIFER COURT, LLC January 3, 2025 Conifer Ridge Project / Fontana J.N. 24-229 Page 6 Excavation Samples At the request of the client, all 25 soil samples (and 2 duplicates) collected from the excavations on August 22, 2024 were tested discreetly for the Soluble Threshold Limit Concentration (STLC) for Total Lead and Chromium by EPA Method 6010b. Seven soil samples (and 1 duplicate) collected from the additional removal excavations on September 20, 2024 were tested discreetly for the Total Threshold Limit Concentration (TTLC) for Total Lead and Chromium by EPA Method 6010b. Stockpile Samples Ten soil samples (and 1 duplicate) collected from the stockpiles on August 22, 2024 were discretely tested for Title 22 Metals by EPA Method 6010b/7010B, Total Petroleum Hydrocarbon (TPH)-carbon range by EPA Test Method 8015B, and Volatile Organic Compounds (VOCs) by EPA Test Method 8260B. Subsequently, four soil samples (and 1 duplicate) collected from the second group of stockpiles on September 20, 2024 were discretely analyzed for the TTLC for Title 22 Metals by EPA Method 6010b/7010B, Total Petroleum Hydrocarbon (TPH)-carbon range by EPA Test Method 8015B, and Volatile Organic Compounds (VOCs) by EPA Test Method 8260B. Results of Removal Verification Sample Analysis • Lead STLC analytical results from 17 of the 25 soil samples (and 2 duplicates) collected from the soil excavations on August 22, 2024 reported detectable STLC concentrations of lead, ranging from 0.167 milligrams per liter (mg/L) to 13.5 mg/L. Concentrations exceeding the STLC limit of 5.0 mg/L were reported in samples S-3 RVS-3 (6.84 mg/L); S-3 RVS-5 (10.2 mg/L); S-5 RVS-2 (6.34 mg/L);S-5 RVS-3 (13.5 mg/L); S-17 RVS-3 (8.49 mg/L); S-17 RVS-4 (7.52 mg/L); and S-17 RVS-5 (6.60 mg/L). Additional removals were recommended in these areas. All excavation removal verification samples from S-2 and S-4 were reported with STLC Lead concentrations less than the limit and required no additional excavation. Subsequently, analysis of the seven soil samples (and 1 duplicate) collected from the additional soil excavations on September 20, 2024 reported detectable TTLC concentrations of lead ranging from 11.3 milligrams per kilogram (mg/kg) to 30.2 mg/kg. These results indicate that all secondary excavation removal verification samples from S-3, S-5, and S-17 were reported with TTLC Lead concentrations less than the USEPA Regional Screening Level (RSL) for Lead of 200 mg/kg (USEPA, 2024) and the DTSC DRAFT DRAFT CONIFER COURT, LLC January 3, 2025 Conifer Ridge Project / Fontana J.N. 24-229 Page 7 Screening Level (SL) of 80 mg/kg (DTSC, 2022) and required no additional excavation. Test results are summarized in Table 1 at the end of this report. The laboratory test results are included in Appendix A. • Chromium None of the 25 soil samples (and 2 duplicates) collected on August 22, 2024 analyzed for the Chromium STLC reported detectable levels above the laboratory reporting limit of 0.05 mg/L (i.e., non-detect). Test results are summarized in Tables 1 at the end of this report. The laboratory test results are included in Appendix A. Based upon the lack of detectable concentrations of Chromium from the initial samples, none of the 7 soil samples (and 1 duplicate) collected from the additional excavations on September 20, 2024 were analyzed for the Chromium. Results of Soil Stockpile Sampling Analysis • Lead STLC analytical results from 5 of the 10 soil samples (and 1 duplicates) collected on August 22, 2024 from the soil stockpiles reported detectable concentrations of Lead, ranging from 1.33 mg/L to 4.26 mg/L. All excavation stockpile samples were reported with STLC Lead concentrations less than the STLC limit of 5 mg/L. Test results are summarized in Table 1 at the end of this report. The laboratory test results are included in Appendix A. • Chromium One of the 10 soil samples (and 1 duplicate) collected on August 22, 2024 analyzed for the Chromium STLC reported a detectable level slightly above the laboratory reporting limit of 0.05 mg/L. The sample S17 SSS-2 reported a STLC Chromium concentration of 0.053 mg/L. All excavation stockpile samples were reported with STLC Lead concentrations less than the STLC limit of 5 mg/L. Test results are summarized in Table 1 at the end of this report. The laboratory test results are included in Appendix A. • Title 22 Metals In addition to the samples analyzed specifically for Lead and Chromium STLC’s, and for offsite disposal characterization, five samples collected on August 22, 2024 from the stockpiles were analyzed for Title 22 Metals. Detectable TTLC concentrations of Barium, Chromium, Cobalt, Copper, Mercury, Nickel, Vanadium, and Zinc were reported at levels below their individual DTSC SLs (2022), USEPA RSLs (2024), DRAFT DRAFT CONIFER COURT, LLC January 3, 2025 Conifer Ridge Project / Fontana J.N. 24-229 Page 8 and/or SFBRWQCB ESLs (2019). One sample, S17 SSS-2, reported Cadmium at 0.512 mg/kg. Total Chromium concentrations ranged from 26.1 mg/kg to 48.3 mg/kg. Lead concentrations ranged from 1.06 mg/kg to 53.3 mg/kg. None of the four discrete soil stockpile samples (and one duplicate) collected on September 20, 2024 reported detectable concentrations of Title 22 Metal elements above their respective DTSC SL (2022) or USEPA RL (2024) for residential soil use except one. The sample S5 SSS-3 reported a TTLC level of 51.4 mg/kg, slightly above the recommended concentration of 50 mg/kg triggering STLC analysis. The STLC results for this sample reported non-detect results, or a concentration below the laboratory Practical Quantitation Limit (PQL) of 0.05 mg/L. Test results are summarized in Table 2 at the end of this report. The laboratory test results are included in Appendix A. • Total Petroleum Hydrocarbons Carbon Chain For offsite disposal characterization, five discrete soil samples collected on August 22, 2024 were tested for gasoline, diesel, and motor oil carbon chain total petroleum hydrocarbons (TPH) using EPA Method 8015B (S2 SSS-2, S3 SSS-2, S4 SSS-2, S5 SSS-2, and S17 SSS-2). No gasoline or diesel range levels were detected above the detection limit of 10 mg/kg (i.e., non-detect). No motor oil range soil residues were reported above the detection limit of 50 mg/kg (i.e., non-detect). Test results are summarized in Table 3 at the end of this report. The laboratory test results are included in Appendix A. None of the four discrete soil stockpile samples (and 1 duplicate) collected on September 20, 2024 reported detectable concentration of gasoline, diesel, and motor oil carbon chain total petroleum hydrocarbons. It should be noted that the November 2024 US EPA Region 9 Regional Screening Levels (RSLs) provide concentrations for Total Petroleum Hydrocarbons as “aliphatic” high, medium and low, and “aromatic” high, medium and low; however, the user’s guide state that, “the carbon range used in the RSLs are not intended to screen against DRO (diesel range organics), GRO (gasoline range organics), ORO (oil range organics) and RRO analysis”. As such, Environmental Screening Levels (ESLs) by the San Francisco Bay Regional Water Quality Control Board were use to assess reported TPH concentrations (SFBRWQCB, 2019). • Volatile Organic Compounds For offsite disposal characterization, five discrete soil samples collected on August 22, 2024 were tested for Volatile Organic Compounds (VOCs). All concentrations in all soil samples analyzed were reported as non-detect, or below the laboratories PQL for the test method of each analyte. DRAFT DRAFT CONIFER COURT, LLC January 3, 2025 Conifer Ridge Project / Fontana J.N. 24-229 Page 9 None of the four discrete soil stockpile samples (and 1 duplicate) collected on September 20, 2024 reported detectable concentrations of any VOC analyte above the laboratory PQL (i.e., non-detect). Test results are summarized in Table 4 at the end of this report. The laboratory test results are included in Appendix A. CONCLUSIONS Based upon the laboratory test results reported herein, elevated STLC levels of Lead soil residues collected from the five remedial excavation areas (S-2, S-3, S-4, S-5, and S-17) were reported below the limit concentration of 5.0 mg/L in 20 of 25 initial remedial excavation verification samples (and 2 duplicates). Seven additional samples collected for further excavation in S-3, S-5, and S-17 reported TTLC Lead residues well below the DTSC SL of 80 mg/kg. Elevated STLC concentrations of Chromium soil residues were not reported in any of the remedial excavation verification samples. STLC results from 10 stockpile samples (and 1 duplicate) collected from the five remedial excavation areas (S-2, S-3, S-4, S-5, and S17) reported no elevated Lead soil residues above the limit concentration of 5.0 mg/L. Furthermore, TTLC results from the 10 stockpile samples (and 1 duplicate) reported no elevated Lead concentrations above the DTSC SL of 80 mg/kg. Detected STLC concentrations of Chromium soil residues were not reported in any of the soil stockpile samples. TTLC concentrations of Chromium soil residues were not reported above the DTSC SL of 160 mg/kg in any of the soil stockpile samples. Based upon laboratory tests results, stockpiled soils are suitable for unrestricted offsite disposal. Stockpiled soils were also analyzed for offsite disposal characterization. The 10 stockpile samples (and 1 duplicate), analyzed for TPH-g, TPH-d, and TPH-mo, reported non-detectable concentrations. The soil samples, also analyzed for VOCs, reported non-detectable concentrations. Based upon TPH and VOC laboratory tests results, stockpiled soils are suitable for unrestricted offsite disposal. Discussion • Stockpile Sampling Protocol As previously noted, the DTSC Information Advisory Clean Import Fill Material Fact Sheet (dated October 2001) was reviewed for stockpile sampling guidance. Information provided by the contractor (The Hilldale Group) indicated approximately 115 cubic yards of soil was exported from the subject property. Based upon the DTSC’s recommended samples per volume of area stockpile of 1 sample per 250 cubic yards for a stockpile up to 1,000 cubic yards, analytical results from the 14 stockpile samples (and 2 DRAFT DRAFT CONIFER COURT, LLC January 3, 2025 Conifer Ridge Project / Fontana J.N. 24-229 Page 10 duplicates), which were collected and analyzed from the subject area, were sufficient to properly characterize the export soils as non-hazardous materials. • Variation in Laboratory Results Site-specific conditions explain the differences in Lead and Chromium soil residue concentrations reported during the Phase II Soil Residues Survey (Petra, 2024) and the remedial excavations and soil stockpile analysis reported herein. Conditions include disturbance of the property by brushing of the site for fire protection purposes and removal of dumped trash and debris. Disturbance of the property was conducted by the previous property owner without regard to open sample test pits on the vacant rock quarry site. Changes in the landscape of the site were significant during removal of trash and debris throughout the subject property including creating access roads. Furthermore, distribution of Lead residues encountered during the Phase II Survey was not uniform and consistent. Seven of the 25 removal verification samples (RVS) collected from the five remedial excavations sidewalls and bottoms reported STLC concentrations of Lead above the screening threshold for non-RCRA California Hazardous Waste. During excavation and stockpile operations soils were mixed and soil residues were homogenized, which explains the lower stockpile Lead concentration results. The second phase of remedial excavations in proximity to the seven elevated STLC Lead concentrations indicate that soils remaining in- place do not contain hazardous Lead residues. Transportation of Stockpiled Soil We understand that all stockpiled soil generated from the five excavations were exported from the subject property. It is our understanding that scheduling export trucks was coordinated by the contractor, Hillsdale Group. The principal carrier of the soil was listed as DC Dispatch. The export trucks were identified as Super-10 dump trucks and strongarm trucks. Discussions with the excavation contractor (Hillside Group) indicated that the super-10 export truck capacity was approximately 12 to 14 cubic yards. The strongarm truck loads were approximately 18-19 cubic yards. The first round of stockpiled soil export from the subject property was on September 5, 2024. This consisted of four loads of stockpiled soils from S-2 and S-4, which reported no elevated residue concentrations of Lead, Chromium, Title 22 Metals, Total Petroleum Hydrocarbons, and Volatile Organic Compounds. One of the loads was described as rock. The second round of stockpiled soil export from the subject property was on November 27, 2024. This consisted of stockpiled soils from S-3, S-5, and S-17 generated from the second phase of excavation, which DRAFT DRAFT CONIFER COURT, LLC January 3, 2025 Conifer Ridge Project / Fontana J.N. 24-229 Page 11 reported no elevated residue concentrations of Lead, Chromium, Title 22 Metals, Total Petroleum Hydrocarbons, and Volatile Organic Compounds. Six loads were removed from the subject property. Overall, a total of 8 soil (115 cubic yards) and 2 rock loads, were removed from the subject property. It should be noted, however, that not all boulders encountered in the excavations were removed from the subject property. Bill-of-Lading Based upon the absence of elevated concentrations of Lead and Chromium residues reported by laboratory testing of all recent soil samples collected from the stockpiled soils onsite, a “Bill-of-Lading” was used for all export loads. Weight of the loads were not provided. A copy of the documents is provided in Appendix B. Disposal Facility Petra provided all laboratory test results to the client to forward to the soil disposal facility for review and acceptance prior to removal from the property. All stockpiled soil removed from the subject property during the first phase and three of the loads from the second phase were exported to the Agua Mansa Properties, Inc. facility, 588 Agua Mansa Road, Rialto, California. Three of the second phase loads that did not contain concrete and only small rock fragments were taken to the 91 71 LLC dump site operated by SUKUT Construction, LLC in Chino, California. Reporting and Field Oversight Field oversight of the excavations and soil stockpiles sampling was performed by Petra. Documentation Documentation of field activities by Petra include the following: 1. Collected soil samples from the 5 remedial excavations and associated soil stockpiles described herein. 2. Laboratory reports associated with soil confirmation and stockpile sampling including chain-of- custody (COC) documents (Appendix A). 3. Copies of the Bill-of-Lading for the soil export loads (Appendix B). DRAFT DRAFT CONIFER COURT, LLC January 3, 2025 Conifer Ridge Project / Fontana J.N. 24-229 Page 12 LIMITATIONS This Excavation, Transportation, and Disposal Completion Report is based upon the project as described herein. This report has been prepared for Conifer Court, LLC, and not for use by parties or projects other than those named or described in this report. The completion report is based upon soil confirmation field sampling and laboratory test results. The completion report has been derived in accordance with current standards of practice, and no warranty is expressed or implied. This opportunity to be of service to you is sincerely appreciated. Please do not hesitate to call this office if you have questions pertaining to this report. Respectfully submitted, PETRA GEOSCIENCES, INC. ______________________________ 1/3/25 Edward Lump Siamak Jafroudi, PhD Associate Geologist Senior Principal Engineer PG 5975 GE 2024 EL/JC/SJ/lv Distribution: (1) Addressee (electronic) (1) Mr. Bryan Avilla (electronic) (1) Mr. Ian Harvey (electronic) W:\2020-2025\2024\200\24-229\Reports\24-229 540 Excavation and Transportation Completion Report.docx DRAFT CONIFER COURT, LLC January 3, 2025 Conifer Ridge Project / Fontana J.N. 24-229 Page 13 REFERENCES Department of Toxic Substances Control (DTSC), 2022, DTSC-Recommended Screening Levels for Soil Analytes, Table 1 Residential, HHRA Note No. 3, June 2020, revised May. _______, 2001, DTSC Information Advisory Clean Imported Fill Material Fact Sheet, Site Mitigation and Restoration Program, dated October. Petra Geosciences, Inc., 2024, Phase I Environmental Site Assessment and Limited Phase II Metals Soil Residue Survey; Conifer Ridge Property, 14.5 Acres of Vacant Land South of Conifer Court and Village Drive, APN 0237-411-27-0000, City of Fontana, San Bernardino County, California 92337, J.N. 24-229, dated June 17. United States Environmental Protection Agency (US EPA), 2024, Regional Screening Level (RSL) Summary Table (TR=1E -06, HQ=1), dated November. DRAFT CONIFER COURT, LLC January 3, 2025 Conifer Ridge Project / Fontana J.N. 24-229 TABLE 1 Summary of Lead and Total Chromium STLC Results Sample ID TTLC(4) Lead (mg/kg)(1) STLC(5) Lead (mg/L)(3) TTLC Total Chromium (mg/kg) STLC Total Chromium (mg/L) Removal Excavation Verification Samples S2 RVS-1 NT(2) ND NT < 0.05(11) S2 RVS-2 NT ND NT < 0.05 S2 RVS-3 NT 1.54 NT < 0.05 S2 RVS-4 NT 0.167 NT < 0.05 S2 RVS-5 NT 0.668 NT < 0.05 S2 RVS-5 Dup NT 1.01 NT < 0.05 S3 RVS-1 NT ND NT < 0.05 S3 RVS-2 NT ND NT < 0.05 S3 RVS-3 NT 6.84 NT < 0.05 S3 RVS-3A(10) 22.5 NT NT NT S3 RVS-4 NT 0.773 NT < 0.05 S3 RVS-5 NT 10.2 NT < 0.05 S3 RVS-5A(10) 29.2 NT NT NT S3 RVS-5A (Dup) (10) 30.4 NT NT NT S4 RVS-1 NT 3.51 NT < 0.05 S4 RVS-2 NT 1.29 NT < 0.05 S4 RVS-3 NT 2.25 NT < 0.05 S4 RVS-4 NT ND NT < 0.05 S4 RVS-5 NT ND NT < 0.05 S5 RVS-1 NT < 0.05 NT < 0.05 S5 RVS-2 NT 6.34 NT < 0.05 S5 RVS-2A(10) 29.8 NT NT NT S5 RVS-3 NT 13.5 NT < 0.05 S5 RVS-3A(10) 11.3 NT NT NT S5 RVS-4 NT 1.99 NT < 0.05 S5 RVS-5 NT 0.403 NT < 0.05 S17 RVS-1 NT ND NT < 0.05 S17 RVS-5 Dup NT ND NT < 0.05 S17 RVS-2 NT 2.92 NT < 0.05 S17 RVS-3 NT 8.49 NT < 0.05 S17 RVS-3A(10) 29.4 NT NT NT S17 RVS-4 NT 7.52 NT < 0.05 DRAFT CONIFER COURT, LLC January 3, 2025 Conifer Ridge Project / Fontana J.N. 24-229 TABLE 1 Summary of Lead and Total Chromium STLC Results Sample ID TTLC(4) Lead (mg/kg)(1) STLC(5) Lead (mg/L)(3) TTLC Total Chromium (mg/kg) STLC Total Chromium (mg/L) S17 RVS-4A(10) 14.3 NT NT NT S17 RVS-5 NT 6.60 NT < 0.05(11) S17 RVS-5A(10) 22.6 NT NT NT Stockpile Soil Samples S2 SSS-1 NT 4.26 NT < 0.5(11) S2 SSS-2 NT < 0.05 NT < 0.5 S3 SSS-1 NT 2.02 NT < 0.5 S3 SSS-1 Dup NT 3.03 NT < 0.5 S3 SSS-2 NT 2.06 NT < 0.5 S4 SSS-1 NT < 0.05 NT < 0.5 S4 SSS-2 NT < 0.05 NT < 0.5 S5 SSS-1 NT < 0.05 NT < 0.5 S5 SSS-2 NT < 0.05 NT < 0.5 S5 SSS-3 NT NT < 0.05 NT S17 SSS-1 NT < 0.05 NT < 0.5 Industrial Screening Levels 80(6) 400(9) 5.0(7) 160(8) 5.0(7) Notes: (1) Milligrams per kilogram (2) Not tested (3) Milligrams per Liter (4) Total Threshold Limit Concentration (5) Soluble Threshold Limit Concentration (6) Recommended Screening Levels, Industrial Use Soils, HERO Note 3 (DTSC, 2022) (7) CCR-Title 22, Chapter 11, Article 3 (8) San Francisco Bay Regional Water Quality Control Board Environmental Screening Levels (ESL’s) – July 2019 (9) Regional Screening Levels, RSL’s Industrial Land Use (US EPA, May 2024) (10) Second Phase of Removal Verification Sampling (11) Non-detect DRAFT DRAFT CONIFER COURT, LLC January 3, 2025 Conifer Ridge Project / Fontana J.N. 22-229 TABLE 2 Summary of CAM Title 22 Metals (TTLC) – Stockpile Soil Sample ID Sb(15) (mg/kg) As(16) (mg/kg) Ba(5) (mg/kg) Cd(13) (mg/kg) Total Cr(12) (mg/kg) Co(3) (mg/kg) Cu(11) (mg/kg) Lead (mg/kg) Hg(9) (mg/kg) Ni ((2) (mg/kg) Vanadium (mg/kg) Zinc (mg/kg) S2 SSS-2 < 1.0(4) < 0.5(4) 131 < 0.5(4) 26.1 11.0 14.6 12.5 0.038 7.81 50.6 58.2 S3 SSS-2 < 1.0 < 0.5 210 < 0.5 37.3 14.3 35.2 53.3 0.066 12.2 63.6 112 S4 SSS-2 < 1.0 < 0.5 156 < 0.5 29.1 12.0 13.7 4.61 0.054 7.36 55.6 49.1 S5 SSS-2 < 1.0 < 0.5 276 < 0.5 48.3 17.0 17.5 1.06 0.041 13.1 75.1 48.5 S17 SSS-2 < 1.0 < 0.5 176 0.512 32.0 12.6 35.4 28.1 0.354 11.2 58.2 105 S3 SSS-3 < 1.0 1.32 228 < 0.5 44.4 14.5 21.2 12.0 0.032 12.7 65.6 60.6 S3 SSS-3 (Dup) < 1.0 1.73 237 < 0.5 43.2 15.4 19.3 12.9 0.023 12.3 67.7 53.0 S5 SSS-3 < 1.0 2.07 269 < 0.5 51.4 16.1 21.3 5.19 0.017 15.3 71.4 54.9 S5 SSS-4 < 1.0 1.13 214 < 0.5 32.9 15.4 15.9 5.78 0.053 7.81 70.8 58.3 S17 SSS-4 < 1.0 3.17 168 < 0.5 39.1 12.7 20.6 12.5 0.019 14.5 54.9 76.6 Screening Levels 470(7) 12.0(6) 3.0(7) 220,000(7) 100(7) 1,100(8) 4,000(10) 160(8) 3,500(7) 43,0007 80(10) 400(7) 46(7) 15,000(8) 5,800(7) 350,000(7) 5,000(14) Notes: (1) Milligrams per kilogram (2) Nickel Compounds (3) Cobalt (4) Non-detect or below the laboratory detection limit (5) Barium (6) Chernoff, G., Bosan, W. and Oudiz, D., 2008 (DTSC) (7) Regional Screening Levels, RSLs (US EPA, May 2024) (8) San Francisco Bay Regional Water Quality Control Board Environmental Screening Levels (ESL’s) – July 2019 (revision 2) (9) Mercury (10) DTSC-Recommended Screening Levels for Residential Soil, HERA Note 3, June 2020 -Revised May 2022 (11) Copper (12) Chromium (13) Cadmium (14) Total Threshold Limit Concentration (TTLC) (15) Antimony (16) Arsenic DRAFT CONIFER COURT, LLC January 3, 2025 Conifer Ridge Project / Fontana J.N. 24-229 TABLE 3 Summary of Total Petroleum Hydrocarbons – Stockpile Soil SAMPLE ID TPH-g(1) (mg/kg)(4) TPH-d(2) (mg/kg) TPH-mo(3) (mg/kg) S2 SSS-2 <10(5) <10(5) <50(5) S3 SSS-2 <10 <10 <50 S4 SSS-2 <10 <10 <50 S5 SSS-2 <10 <10 <50 S17 SSS-2 <10 <10 <50 S3 SSS-3 <10 <10 <50 S3 SSS-3 (Dup) <10 <10 <50 S5 SSS-3 <10 <10 <50 S5 SSS-4 <10 <10 <50 S17 SSS-4 <10 <10 <50 Tier 1 Soil Screening Level(6) 100 100 1,600 Notes: (1) Total Petroleum Hydrocarbons gasoline range organics (2) Total Petroleum Hydrocarbons diesel range organics (3) Total Petroleum Hydrocarbons motor oil range organics (4) Milligrams per kilogram (5) Non-Detect, or below the laboratory detection limit (6) San Francisco Bay Regional Water Quality Control Board Environmental Screening Levels (ESL’s) – July 2019 (Revision 2) DRAFT DRAFT CONIFER COURT, LLC January 3, 2025 Conifer Ridge Project / Fontana J.N. 22-229 TABLE 4 Volatile Organic Compounds – Stockpile Soils VOC(5) Analyte S2 SSS-2 (mg/kg)(1) S3 SSS-2 (mg/kg) S4 SSS-2 (mg/kg) S5 SSS-2 (mg/kg) S17 SSS-2 (mg/kg) S3 SSS-3 (mg/kg) S3 SSS-3 (Dup) (mg/kg) S5 SSS-3 (mg/kg) S5 SSS-4 (mg/kg) S17 SSS-4 (mg/kg) Generic Screening Level (mg/kg) Methylene Chloride <0.010(4) <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 2.2(2) 2-Butanone (MEK) <0.020(4) <0.020 <0.020 <0.020 <0.020 <0.020 <0.020 <0.020 <0.020 <0.020 27,000(3) Benzene < 0.005(4) < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 0.33(2) Carbon Disulfide <0.010(4) <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 770(3) Chloroform < 0.005(4) < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 0.32(2) 4-Methyl-2-pentanone (MIBK) <0.020(4) <0.020 <0.020 <0.020 <0.020 <0.020 <0.020 <0.020 <0.020 <0.020 33,000(3) Toluene < 0.005(4) < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 4,900(3) Tetrachloroethene (PCE) < 0.005(4) < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 0.59(2) Chlorobenzene < 0.005(4) < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 280(3) Ethylbenzene < 0.005(4) < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 5.8(3) m,p-Xylene <0.010(4) <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 550(3) o-Xylene < 0.005(4) < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 640(3) Naphthalene < 0.005(4) < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 2(2) 1,2,4-Trimethylbenzene < 0.005(4) < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 300(3) Trichloroethene (TCE) < 0.005(4) < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 0.94(3) Remaining VOCs ND(4) ND ND ND ND ND ND ND ND ND various Notes: (1) milligrams per kilogram (2) DTSC’s Screening Levels (SLs) for Residential Soil, Table 1, HHRA Note 3, revised May 2022 (3) USEPA’s Regional Screening Levels (RSLs) Summary Table, Residential Soil (November 2024) (4) Non detect or less than the laboratory reporting limit (5) Volatile Organic Compound FIGURES Site Location Map PETRA GEOSCIENCES, INC. COSTA MESA MURRIETA PALM DESERT SANTA CLARITA Figure 1J.N.: SCALE: January 2025 24-229 epl see map DATE: DWG BY: 40880 COUNTY CENTER DRIVE, SUITE M TEMECULA, CALIFORNIA 92591 PHONE: (951) 600-9271 Village Project Fontana. San Bernardino County, California - Approximate Site Location LEGEND N N TP-15 - Approximate location of exploratory test pit - Approximate Location of Exploratory Boring LEGEND B-7 Af Qal - Artificial Fill - Quaternary Young Alluvium - Quaternary/Tertiary Sandstone Qls - Quaternary Landslide Deposits QTsw GEOLOGIC UNITS N SCALE 1 MILE0 SITE - Reproduced from: USGS, 2024, The National Map Viewer Base Map Reference: NewBridge Homes, L LC, 2024, Proprietary Photograph, dated August 22. P E TR A G E O S C I E NC E S, I N C. 40880 County Center Drive, Suite M Temecula, California 92591 PHONE: (714) 549-8921 COSTA MESA TEMECULA VALENCIA PALM DESERT CORONA Excavation and Stockpile Location Map Conifer Court Storage Facility Project Fontana, San Bernardino County, California D ATE:January 2025 J.N.: 24-229 Figure 2 N N TP-15 - Approximate location of exploratory test pit - Approximate Location of Exploratory Boring LEGEND B-7 Af Qal - Artificial Fill - Quaternary Young Alluvium - Quaternary/Tertiary Sandstone Qls - Quaternary Landslide Deposits QTsw G EO L O G I C UN I T S GEOSCIENCES N SC A LE 30+/- ft.0 LEGEN D - Approximate Limits of Remedial Excavation - Approximate Limits of Remedial Soil Stockpile S17 S17 S5 S5 S5 S4 S4 S2S2 S3 S3 S4 S17 S17 S S S -3 S17 S S S-1 S17 S S S-2 S5 S S S-1 S5 S S S-2 S2 S S S -2 S2 S S S-1 S3 S S S -1 S3 S S S-2 S4 S S S -2 S4 S S S-1 - Approximate Soil Stockpile Sample Location - Approximate Removal Verification Soil Sample Location S17 S S S-3 S17 RV S-5 S5 R V S -5 S5 R V S -3 S5 RV S-4 S5 RV S-2 S5 RV S-1 S17 R V S -1 S17 R V S -2 S17 RV S-5 S17 RV S-3 S17 RV S-4 S4 RV S-3 S4 R V S -4 S4 RV S-2 S4 RV S-5 S4 RV S-1 S2 R V S -4 S2 R V S -1 S2 R V S -3 S2 RV S-2 S2 RV S-5 S3 RV S-5 S3 RV S-4 S3 RV S-3 S3 RV S-1 S3 RV S-2 S T L C @ 6.34 S T L C @ 13.5 S T L C @ 8.49 S T L C @ 7.52 S T L C @ 6.60 S T L C @ 6.84 S T L C @ 10.2 - Approximate Soil Sample Location with Lead S T LC (WE T) Results Exceeding C A Hazardous Waste Criteria (Units in mg/L). S T L C @ 8.49 Base Map Reference: P E TR A G E O S C I E NC E S, I N C. 40880 County Center Drive, Suite M Temecula, California 92591 PHONE: (714) 549-8921 COSTA MESA TEMECULA VALENCIA PALM DESERT CORONA Excavation and Sample Location Map, Phase 2 Conifer Court Storage Facility Project Fontana, San Bernardino County, California D ATE: January 2025 J.N.: 24-229 Figure 3 N N TP-15 - Approximate location of exploratory test pit - Approximate Location of Exploratory Boring LEGEND B-7 Af Qal - Artificial Fill - Quaternary Young Alluvium - Quaternary/Tertiary Sandstone Qls - Quaternary Landslide Deposits QTsw G EO L O G I C UN I T S GEOSCIENCES N J.N.: 24-229 SC ALE 30+/- ft.0 S5 S5 SSS-3 S5 S S S-4 S5 S5 S5 RVS-3A S5 RV S-2A S17 S17 S17 SS S-3 S17 S S S-4 S17 RV S-3A S5 RV S-4A S17 RVS-5A S3 S3 SSS-3 S3 RV S-5A S3 RV S-3A LE G E ND Base Map Reference: NewBridge Homes, L LC, 2024, Proprietary Photograph, dated October 4. - Approximate Limits of Former Excavation (Phase 1) - Approximate Limits of Phase 2 Excavation - Approximate Limits of Phase 2 Stockpile - Approximate Location of Phase 2 Excavation Verification Sample - Approximate Location of Phase 2 Stockpile Sample S17 RV S-5A S17 SSS-4 APPENDIX A LABORATORY REPORTS AND CHAIN-OF-CUSTODY DOCUMENTS APPENDIX B BILL-OF-LADING