SAN BERNARDINO COUNTY

SOLID WASTE MANAGEMENT DIVISION

222 West Hospitality Lane, 2nd Floor San Bernardino, CA 92415-0017

SUPPLEMENTAL INFORMATION

TO THE PLANS AND BID DOCUMENTS FOR THE UNIT 2 PHASE 5-2 LINER

CONSTRUCTION PROJECT

AT THE SAN TIMOTEO SANITARY LANDFILL

in Redlands, California

October 19, 2026

The following changes and/or additions are made to the Plans and Bid Documents for the Unit 2 Phase 5-2 Liner Construction Project at the San Timoteo Sanitary Landfill.

I. GENERAL

1. The Paleontological Resources Impact Mitigation Plan (PRIMP) for STSL is included as Attachment 1 of this Supplemental Information. The purpose of this plan is to identify mitigations, monitoring, and compliance measures to reduce potential impacts to paleontological resources during construction. Bidders must be familiarized with the paleo monitoring requirements and must be aware of potentially working around the monitors during the earthwork excavation activities.

II. Questions and Answers from first Advertisement:

Q1. The Warning Sheet that is a part of the specification, states bidders must obtain plans and specifications from department managing the project. Does that mean that bidders have to go and request hard copies from SOLIDWASTE - Public Works - Solid Waste over the counter?

A1. Bidders may obtain the plans and specifications from the Department on a USB drive for a fee or access them through the EPro System. To retrieve the bidding documents through EPro, bidders must be registered and have an active account. Note, to be able to bid on this project, all bidders must be registered with EPro.

Q2. The bid proposal checklist specifies submission of Performance and Payment Bond Forms with the bid. What format should they be submitted in?

A2. The Performance and Payment Bond forms must be submitted in accordance with the requirements specified in the project’s bidding documents.

Bidders should refer to the Instructions to Bidders (yellow pages) for detailed requirements regarding the required format and submission of these forms. The yellow pages contain forms that may be utilized for bonding purposes.

Q3. Will CAD files for the project be provided?

A3.CAD files are available by clicking the link below.

https://amermft.tetratech.com/message/3KlBMjrGu3cH17fRNINQ2g

Q4. Can you please send me the Engineer's Estimate for the Unit 2 Phase 5-2 Liner Construction Project at the San Timoteo Sanitary Landfill project.

A4. The County does not share the Engineer’s Estimate.

Q5. In the Instructions to Bidders (yellow pages) section XII. Lowest Responsible Bid, paragraph 1 refers to a ‘delivery schedule’ proposed by the bidder that will be taken into consideration by the county. Section XVII. Schedule also refers to the bidder preparing an overall schedule for this project. However, the Bid Proposal Checklist and Assembly (pink pages) makes no reference to this schedule. Please confirm if this is to be submitted at bid time.

A5. Project schedule will be submitted by awarded Bidder prior to the start of construction.

Q6. Please provide detailed information on required perils coverages, limits and deductibles for the Builder’s Risk coverage outlined in the Standard Contract, Section 5.3.2, Subsection E. For example, will earthquake and flood perils coverage be required at the full contract amount, or will a coverage sublimit such as $1,000,000 be acceptable?

A6. The Course of Construction/Installation (Builder’s Risk) Property Insurance shall be based on the Contractor’s proposed bid amount.

Q7. The General Conditions, Section 11.2.1.4, states that projects exceeding $10,000,000 require General Liability and Auto Liability limits of no less than two times the total estimated project cost. This results in a liability limit that is much greater than most general contractors carry. Would the Agency be willing to grant an exception to this requirement for this project?

A7. Per the project’s bidding documents, the insurance requirements specified in the General Conditions, Section 11.2 are mandatory. The County will not grant https://amermft.tetratech.com/message/3KlBMjrGu3cH17fRNINQ2g an exception or waiver to the General Liability and Auto Liability insurance limits required for this project. Bidders are required to comply with the insurance requirements as stated in the project’s bidding documents.

Q8. Please confirm whether subcontractors must be listed in ePro when submitting electronically, or if the List of Subcontractors included in the bid package will satisfy the subcontractor listing requirement.

A8. It is not necessary to list subcontractors separately in ePro. Bidders should list all proposed subcontractors for this project on the List of Subcontractors Form provided in the project’s bidding documents. Bidders are required to complete the form in its entirety and ensure that all requested information is provided as specified on the form. The completed List of Subcontractors Form must be submitted as part of the bid package.

Q9. Is there a minimum self-performance percentage for prime contractors?

A9. The SSPWC, Section 3 – Control of the Work, Subsection 3-2-Self Performance states that Contractor shall perform with its own organization contract work amounting to at least 50 percent of the contract price except that any designated “specialty items” may be performed by subcontract.

Q10. Is this project also referred to as “Liner Construction Unit 2 Phase 5B San Timoteo Sanitary Landfill?”

A10. Unit 2 Phase 5 liner was originally designed and permitted as one construction phase. It was then subsequently divided into two construction phases, identified as Phase 5-1 and Phase 5-2. Phase 5-1 has already been constructed. This project consists of completing the remaining portion of Unit 2 Phase 5 Liner, which is referred to as Phase 5-2. Any documentation, plans, specifications, or other project information obtained with the title “Liner Construction Unit 2 Phase 5B San Timoteo Sanitary Landfill” may contain outdated or superseded information. Do not use, rely upon, or incorporate any documents bearing this title for bidding purposes.

Q11. Will the County be issuing an operations layer fill grading plan?

A11. A grading plan will not be provided, the requirements for the grading are in the project specifications. See Section 31 00 00, Subsection 3.4.

Q12. Are there minority goals set for this bid?

A12. There are no minority participation goals established for this bid solicitation.

Q13. The Performance and Payment bonds are included in the Bid Documents and are typically due post award. Please confirm when the Performance and Payment bonds are due.

A13. Performance Bond and Payment Bond are required to be submitted after award of the contract. Section XVIII of the Instructions to Bidders states the Payment Bond shall be furnished prior to the commencement of work under the contract.

Q14. Please confirm that the Subcontractor Non-Collusion Declaration is due four

(4) Working Days after bid opening.

A14. Per the project’s bidding package and requirements, the Subcontractor Non-Collusion Declaration must be submitted with the bid or within four (4) working days after the bid opening.

Q15. Please confirm when the Contractor's Affidavit and Final Release form is due.

A15. The Contractor’s Affidavit and Final Release Form must be submitted following completion of the project and after all outstanding project requirements and obligations have been satisfied and cleared. The completed form is required prior to the release of the project retention and will be part of the documentation required for final payment and closeout.

Q16. Are CARB certs required to be submitted with the bid?

A16. Yes, the CARB certification is one of the required bid submittals and is specifically included in the “Bid Proposal Checklist and Assembly.” As part of the bidding package, both Contractor and Subcontractor CARB Certification Forms are provided and must be properly completed and submitted with the bid.

Failure to submit the required CARB Certification Forms, or failure to comply with any of the applicable requirements, may result in the bid being deemed non-responsive.

Q17. “Section 3.15.3 of the general conditions require a NPDES permit. Section 015000 Article 1.8 Water Pollution Control does not indicate NPDES permit is required. Please clarify”.

A17. Refer to the Subsection 3.15.3 – Water Pollution Control.

As a clarification, no separate Construction General Permit is required for this project since all work will be performed under STSL’s Industrial Permit.

Contractor is responsible for preparing and submitting an Erosion Control Plan for the project for SWMD’s review and approval in accordance with the specifications, Section 01 50 00, Subsection 1.8.

Q18. Subparagraph 8.4.1.3 gives the Contractor no time extension for the first ten

(10) Workdays per year of rain/inclement weather. Contract Time is 350 Working Days, which spans more than one year. Please clarify whether the allowance is 10 Workdays total for the Contract or 10 Workdays for each year, whether "year" means a calendar year or each 12 months from the Date of Commencement, and what the County uses to decide that a day is unworkable.

A18. The ten (10) workday allowance for rain/inclement weather is 10 Workdays total for the entire Project and does not reset annually. The County will determine whether a Workday is unworkable due to rain or inclement weather based on the conditions at the Project site and their impact on the Contractor’s ability to perform the scheduled Work.

Q19. Section 01 20 00, Paragraph 1.3, states that Access Road Excavation and Entrance Road Excavation volumes will be measured and paid under Bid Items 9 through 17, and the Bid Schedule includes Item 16 (Access Road Excavation to Access Road Unclassified Fill, 2,400 CY) and Item 17 (Entrance Road Excavation to Stockpile 3, 5,260 CY). Paragraphs 4.106 (4-Inch AC over 8-Inch CMB) and 4.107 (6-Inch AC over 12-Inch CMB) state that excavation, fill to subgrade, grading, and daylighting to existing are included in the paving unit price and that no separate payment will be made. Please clarify which bid item carries excavation and embankment beneath the paved sections of the Access Road and Entrance Road, including the 1-foot over excavation and recompaction of the roadbed recommended in Section 8.2.2 of the Access Road Widening Geotechnical Report (Reference Document #4).

A19. Please use Bid Item #10, Phase 5-2 Excavation to Access Road Unclassified Fill for the excavation and embankment beneath the paved sections of the Access Road and Entrance Road, including the 1-foot over excavation and recompaction of the roadbed.

Q20. On sheet D-101, the drawings call out for an existing 36" pipe to be removed and salvaged on the north end of the project, how deep is the pipe and is it backfilled with soil, gravel or slurry?

A20. Most of the existing pipe is situated at an approximate depth of 16 feet below grade, with a section extending to approximately 28 feet in depth at the elbow. The resulting void shall be properly backfilled with soil.

Q21. On sheet D-101, the drawings call out for existing channels, ditches and bench crossings to be demoed, what can we assume for thickness of concrete?

A21. The existing concrete thicknesses for the structures identified for demolition on Sheet D-101 shall be assumed as follows:

• Trapezoidal Channels: 6 inches thick

• V-Ditches: 4 inches thick, with 6-inch-thick concrete edges

• Downdrains: Slope anchors every 10-foot vertically. The slope anchors extend 12 inches below the downdrain and have a thickness of 8 inches.

• Bench Crossings: 6 inches thick

Please refer to Project Specifications Section 31 10 00, Subsection 3.1, General for stockpiling requirements for this material.

Q22. On sheet D-101, the drawings call out for "Contractor to pothole to determine limits of existing waste in accordance with General Note 2". However, there is no general note 2 on the sheet. Please advise.

A22. Please refer to the General Notes provided on Sheet C-002. For bidding purposes, assume two (2) days of support which includes excavation, moisture conditioning, backfill placement, and survey activities.

Q23. Section 01 50 00, Paragraph 1.13, states the Contractor shall not interrupt two-way traffic at the site, and that landfill traffic will be switched from the eastern access road to the western access road between April and June 2027. The Contract Agreement, Section 3.1, Milestone 3, requires Access Road Improvements (Sheets C-401 through C-409) to be completed within 65 Working Days of that switch.

Please confirm: A) That the Access Road shown on Sheets C-401 through C-404 will be closed to landfill operations traffic during the 65-Working-Day improvement window. B) Whether the Entrance Road improvements on Sheets C-302 through C- 304 must be constructed under live landfill traffic, and if so, whether half-width construction with traffic control is required. C) Whether the start of the 65-Working- Day window is contingent on the County's switchover date, and how a delayed switchover will be treated with respect to Contract Time.

A23. Please see responses below.

A) Please refer to the revised Project Specifications Section 01 50 00, Subsection 1.13, Traffic Control, Paragraph D.

B) Weekend and/or night work will be required during the Entrance Road improvements on Sheets C-302 through C-304 to keep both scales operating during normal hours. The Contractor shall account for high strength/quick setting concrete, temporary protection and traffic control as necessary to accommodate two-way traffic and scale operations.

C) The start of the 65-working-day window is contingent on the County’s switchover date, if the switchover is delayed to the point that the 65-working-day period extends beyond the Contract Time, the Contract Time will be adjusted accordingly.

Q24. Section 01 20 00, Paragraph 4.110, states the 6-Inch AC Curb Type D1-6 with 2' openings every 10' (Bid Item 110, 205 LF) will be paid per actual linear footage installed. Please confirm whether the pay quantity is measured along the full curb alignment (gross) or excludes the 2-foot openings (net).

A24. The pay quantity for Bid Item 110, 6-Inch AC Curb Type D1-6 with 2-foot openings every 10 feet, shall be measured along the full curb alignment (gross).

Q25. On Sheet D-102, the drawings call out for the existing channel and asphalt pavement to be demoed, what can we assume for thickness of both?

A25. For bidding purposes, contractors shall assume the existing access road consists of 6 inches of asphalt concrete (AC) over 12 inches of crushed miscellaneous base (CMB). The existing channel shall be assumed to consist of 6-inch-thick concrete with block extension. Please refer to the Project Specifications Section 31 10 00, Clearing, Grubbing, and Demolition, Subsection 3.1, General for stockpiling requirements for this material.

Q26. Regarding Sheet C-603, please provide detail on how the catwalk for the leachate tanks needs to be built. What is the required height of the catwalk?

A26. As noted on Sheet C-603, the new catwalk shall match the existing landing height. The Contractor shall submit shop drawings for the proposed catwalk for approval prior to construction.

Q27. On sheet C-302, construction note 157, construct dual wall solid LCRS pipe, there is no profile or elevations indicated on the drawings, what should we assume for depth of trench to install?

A27. As indicated on Sheet C-302, the Contractor shall locate the existing LCRS pipe and provide the resulting survey data to the Engineer in accordance with General Note 2 on Sheet C-002. For bidding purposes, the Contractor shall assume an average trench depth of 3 feet.

Q28. In the event that selected soil doesn’t meet spec for the LPL as directed by the CQA, where does the Contractor get compensated to move the soil?

A28. The costs should be included in Bid Item 11 – Phase 5-2 Excavation to Stockpile 3.

Q29. Earthwork Section 31 00 00, spec 2.1, slope liner subgrade on the upper 12" thick section shall consist of 1" screened material. Is the Contractor expected to place the 1" screened material at an equipment width, concurrently and adjacent as the buttress fill is being placed? What are the compaction requirements for the 12" section?

A29. Please refer to Detail 2/C-501. The means and methods for achieving the requirements are not specified and shall be determined by the Contractor. The compaction requirements for the buttress fill also apply to this section of fill.

Please refer to Project Specifications Section 31 00 00, Table 31 00 00(B), for compaction requirements.

Q30. Earthwork Section 31 00 00, spec 3.4 states that the Contractor is to provide daily cover to operations. Under which bid item does this get paid and where is the location and elevation for this material to be stockpiled?

A30. Bid Item 12 - Phase 5-2 Excavation to Stockpile A (Deletable), Bid Item 13 - Phase 5-2 Excavation to Stockpile B (Deletable), and Bid Item 14 - Phase 5-2 Excavation to Stockpile C (Deletable). The locations of Stockpiles A, B and C are shown on Sheet C-001.

Q31. Earthwork Section 31 00 00, states material is not to be larger than 3" for the backfill material of the MSE wall, is this material expected to be screened from onsite soils?

A31. The onsite soil shall be selectively excavated, processed or screened in order to meet the specifications.

Attachment 1

Paleontological Resources Impact Mitigation Plan

2026-505/San Timoteo Sanitary Landfill Project Rocklin ♦ Redlands ♦ Irvine ♦ San Diego ♦ Chico ♦ Santa Fe ♦ Fresno ♦ ecorpconsulting.com

September 9, 2026

Cole Duncan, P.E.

Project Manager SWT Engineering 800-C South Rochester Avenue Ontario, CA 91761 Sent via email: ctd@swteng.com

RE: Paleontological Resources Impact Mitigation Plan for the San Timoteo Sanitary Landfill Project, San Bernardino County, California

Dear Cole Duncan:

ECORP Consulting, Inc. (ECORP) prepared this Paleontological Resources Impact Mitigation Plan (PRIMP) for the San Timoteo Sanitary Landfill Project (Project) in the City of Redlands, San Bernardino County (County), California (Appendix A, Figure 1). This Project involves the construction of Unit 2, Phase 5-2 composite liner systems and includes extensive earthwork, including excavation, subgrade preparation, and placement of low-permeability layers, leachate collection and removal system gravel, and operations layers. Key civil improvements include entrance and perimeter access roads, striping, signage, retaining walls, fire water lines and hydrants, and perimeter fencing. Landfill gas improvements, including piping and associated components, are also part of the work. The Project will also add two leachate tanks with associated pumps, controls, and electrical improvements, modify the existing leachate tank and secondary containment, and incorporate drainage improvements.

This PRIMP is designed to identify mitigation, monitoring, and compliance measures to reduce potential impacts to paleontological resources in accordance with the Society of Vertebrate Paleontology (SVP;

2010) and other laws and regulations. This PRIMP follows these conditions:

1. Prior to the start of grading/earth-moving activities, a Qualified Paleontologist approved by the County shall be retained to create and implement a Project-specific plan for monitoring onsite earth-moving activities (Project Paleontologist). A qualified paleontological monitor will be onsite and oversee all paleontological mitigation, including providing a worker environmental awareness training program. The training will discuss field procedures conducted by the paleontological monitor, types of fossils that may be encountered, laws and regulations governed in protecting paleontological resources, and fossil discovery notification protocols. The Project Paleontologist shall receive and review the approved development and grading plans from the Contractor. A copy of this PRIMP shall be submitted to the County for approval prior to earth-moving activities.

This PRIMP also includes the following:

a. Description of the proposed site and planned grading operations (if provided).

b. Description of the level of monitoring required for all earth-moving activities within the Project Area where highly sensitive units are observed.

mailto:ctd@swteng.com

ECORP Consulting, Inc. 2 September 9, 2026 San Timoteo Sanitary Landfill Project 2026-505

c. Identification and qualifications of the qualified paleontological monitor to be employed for monitoring and supervision of other monitor(s).

d. Identification of personnel with authority and responsibility to temporarily halt or divert construction equipment to allow for recovery of large specimens.

e. Direction for any fossil discoveries to be immediately reported to the Project developer.

f. Means and methods to be employed by the paleontological monitor to quickly salvage fossils as they are unearthed to avoid construction delays.

g. Procedures and protocol for collecting and processing samples and specimens. Sampling of sediments is likely to contain the remains of small fossil invertebrates and vertebrates.

h. Fossil identification and curation procedures to be employed.

i. Identification of the permanent repository to receive any recovered fossil material. A written agreement between the Project developer and the repository must be in place prior to site grading.

j. All pertinent exhibits, maps, and references.

k. Procedures for reporting findings.

l. Identification and acknowledgment of the developer for the content of the PRIMP, as well as acceptance of financial responsibility for monitoring, reporting, and curation fees. The Project developer shall provide appropriate funding for monitoring, reporting, delivering, and curating the fossils at the institution where the fossils will be placed and will provide confirmation to the County that such funding has been paid to the institution.

m. All final reports shall be signed by the Project Paleontologist; one original signed copy of the report(s) shall be submitted to the County along with a copy of this condition and the grading plan for appropriate case processing and tracking.

ECORP’s Principal Paleontologist, Niranjala Kottachchi, has been retained as the Project Paleontologist to fulfill the conditions above. Appendix B provides her qualifications and the qualifications of the paleontological monitor.

ECORP Consulting, Inc. 3 September 9, 2026

BACKGROUND AND SETTING

The Project Area is located within the City of Redlands, which is a region within the Peninsular Ranges Geomorphic Province of Southern California in the central portion of the San Bernardino Valley (Lancaster et al. 2012; Morton and Miller 2006; Webb Associates 2022). The Peninsular Ranges province consists of several northwesterly trending ranges in Southwestern California. Prior to the mid-Mesozoic, the region was covered by seas and thick marine sedimentary and volcanic sequences. During the Cretaceous, extensive mountain building occurred during the emplacement of the Southern California batholith. By the Tertiary and Quaternary periods, strike-slip faulting along the San Jacinto and Elsinore faults took place, and this tectonic activity resulted in the present-day terrain (City of Beaumont 2022).

Bortugno and Spittler (1986) described the geology of the Project Area as containing Pleistocene and/or Pliocene sandstone, shale, and loosely consolidate gravel deposits of the San Timoteo Formation.

Quaternary (Pleistocene and/or Holocene) unconsolidated and semi-consolidated alluvium, lake, playa, and terrace deposits may be found in the southwestern portion of the Project Area (Appendix A, Figure 2).

Geotechnical studies were conducted for the Beaumont Summit Station Specific Plan, with boring depths ranging from 10 to 50 feet and trenching to depths of 6.5 to 10.5 feet below existing grade. Subsurface soils consisted of artificial fill at the surface, alluvium, and older alluvium with depth. Similarities in the stratigraphy suggest that the Project Area will also show this. The older alluvium is significant because it has the highest potential of containing paleontological resources; it consists of medium dense to very dense silty fine sands, silty fine to medium sands, and silty fine to coarse sands with some hard sandy clays (City of Beaumont 2022). One additional geologic unit of interest may be encountered within the Project Area with depth: the San Timoteo Formation, which is composed of dark gray-green, fissile mudrock, with interbedded paleo brown sandstone and reddish-brown, clay-rich paleosols (Clifford 2017).

This formation is significant because it has yielded numerous and diverse fauna.

ECORP Consulting, Inc. 4 September 9, 2026

PALEONTOLOGICAL RESOURCES

As defined by the SVP guidelines, significant paleontological resources are fossils and fossiliferous deposits, herein defined as consisting of identifiable vertebrate fossils, large or small, uncommon invertebrate, plant, and trace fossils, and other data that provide taphonomic, taxonomic, phylogenetic paleoecologic, stratigraphic, and/or biochronologic information. Paleontological resources are considered to be older than recorded human history and/or older than middle Holocene (i.e., older than about 5,000 radiocarbon years) (SVP 2010). Body fossils include bones, teeth, shells, leaves, and wood, whereas trace fossils include trails, trackways, footprints, burrows, coprolites, and eggshells. The fossil record is the only evidence that life on earth has existed for more than 3.6 billion years. Fossils are important scientific and educational resources because they are used to:

study the phylogenetic relationships among extinct organisms, as well as their relationships to modern groups;

elucidate the taphonomic behavioral, temporal, and diagenetic pathways responsible for fossil preservation, including the biases inherent in the fossil record;

reconstruct ancient environments, climate change, and paleoecological relationships;

provide a measure of relative geologic dating that forms the basis for biochronology and biostratigraphy, and which is an independent and corroborating line of evidence for isotopic dating;

study the geographic distribution of organisms and tectonic movements of land masses and ocean basins through time;

study patterns and processes of evolution, extinction, and speciation; and identify past and potential future human-caused effects to global environments and climates.

California law mandates efforts to mitigate adverse effects to paleontological resources because disturbance of previously undisturbed sediments can damage or destroy significant paleontological resources, and because fossils are considered to be nonrenewable resources.

ECORP Consulting, Inc. 5 September 9, 2026

PALEONTOLOGICAL POTENTIAL/SENSITIVITY

To assess the significance of a geologic unit to contain paleontological resources (i.e., paleontological potential/sensitivity), paleontologists have adopted the standards set forth by the SVP (2010). The SVP defines four categories of paleontological potential/sensitivity for geologic units: high, low, undetermined, and no potential. The following sections describe each category.

High Potential/Sensitivity

High sensitivity is assigned to geologic units that are known to contain paleontological localities with rare, well-preserved, critical fossil materials for stratigraphic or paleoenvironmental interpretation, and fossils that provide important information about the paleobiology and evolutionary history (phylogeny) of animal and plant groups. Highly sensitive formations produce vertebrate fossil remains or are considered to have the potential to produce such remains.

Low Potential/Sensitivity

Low sensitivity is assigned to geologic units that, based on their relative youthful age and/or high-energy depositional history, are determined to be unlikely to produce important fossil remains. Typically, low-sensitivity formations produce invertebrate fossil remains in low abundance. Low paleontological potential is also assigned to geologic formations that are entirely igneous in origin and therefore have no potential for producing fossil remains, or to artificial fill materials, which lose the stratigraphic/geologic context of any contained organic remains (such as fossils).

Undetermined Potential/Sensitivity

Undetermined sensitivity is assigned to geologic units that exhibit geologic features and preservation conditions that suggest significant fossils could be present, but little information about the geology and/or paleontological resources of the unit or the site is known. This may indicate that the unit or site is poorly studied, and field surveys may be useful to more precisely determine the paleontological sensitivity.

No Potential/Sensitivity

Rock units of metamorphic or igneous origin are commonly classified as having no potential for containing significant paleontological resources.

ECORP conducted a desktop study of known paleontological resources for the Project Area and vicinity.

The nearest known Pleistocene-age fossil locality is a specimen of Bison antiquus, which is an extinct species of bison (Smith B. F. and Associates, Inc. 2021). Another locality was in the area of Calimesa Boulevard; it consisted of the remains of an extinct species of horse (Equus), which was found in late- to middle-Pleistocene-age alluvial fan deposits. The slightly older San Timoteo Formation of the late Pliocene to middle Pleistocene (3.5 to 0.7 million years ago) has produced numerous fossils, including at least 30 mammalian and reptilian species. In addition, fossil specimens of camel, horse, deer, and whipsnake have been recovered in the Beaumont site from shallow depths of 9 to 11 feet below ground

ECORP Consulting, Inc. 6 September 9, 2026 surface (Clifford 2017). Initial contact with the San Bernardino County Museum has indicated that an abundance of fossils is currently curated at the museum from the San Mateo Formation within the Project Area. Fossils discovered from the San Timoteo Formation are significant because they not only provide a more complete fossil record for the late Cenozoic but also constrain dates and assist with magnetostratigraphy, paleogeography, paleoclimate reconstructions, and timing of prehistoric faunal migrations (Clifford 2017). For these reasons, the Project Area has a high potential/sensitivity.

RECOMMENDATIONS

Due to the high potential of the Project Area to produce paleontological resources, ECORP recommends full-time monitoring. A qualified paleontological monitor should be retained if excavations exceed disturbed soils and recent alluvium and encounter highly sensitive Quaternary older alluvium and the San Timoteo Formation. Because the geologic units can vary throughout the Project Area, the monitor will need to rely on the Project supervisor to inform them of when excavations will take place in undisturbed native sediment. The Contractor shall provide a copy of earth-moving construction plans to the qualified Project Paleontologist prior to the start of construction.

Monitoring Requirements

A qualified paleontological monitor shall be retained and work under the supervision of the Project Paleontologist. The following guidelines of the SVP (2010) state the qualifications of such a monitor.

Paleontological resource monitors shall have the equivalent of the following qualifications:

1. BS or BA in geology or paleontology and 1 year of experience monitoring in the state or geologic province of the specific project. An associate degree and/or demonstrated experience showing ability to recognize fossils in a biostratigraphic context and recover vertebrate fossils in the field may be substituted for a degree.

An undergraduate degree in geology or paleontology is preferable, but is less important than documented experience performing paleontological monitoring, or

2. AS or AA in geology, paleontology, or biology and demonstrated 2 years’ experience collecting and salvaging fossil materials in the state or geologic province of the specific project, or

3. enrollment in upper division classes pursuing a degree in the fields of geology or paleontology and 2 years of monitoring experience in the state or geologic province of the specific project.

4. Monitors must demonstrate proficiency in recognizing various types of fossils, in collection methods, and in other paleontological field techniques.

Paleontological resource monitoring of construction excavations involves field inspections of cut slopes, trenches, and spoils piles. Additional paleontological monitors may be required to cover these activities should excavations occur concurrently in multiple locations within the Project Area. Test sampling will be conducted if potentially fossiliferous sediments have been encountered. Test sampling consists of

ECORP Consulting, Inc. 7 September 9, 2026 removing a small amount of sediment (typically 200 pounds) and analyzing it for microvertebrate fossils by passing it through a series of sieves with a minimum screen size of 30 mesh. In most cases, screening is done by wet-sieving, and the resulting concentrate is then dried and examined under a microscope. If initial screening produces microvertebrates, the guidelines of the SVP (2010) mandate that an additional 6,000-pound sample be processed for microvertebrate fossils from the fossil-producing horizon. This larger sample can be set aside within the Project Area away from construction activities and later sieved onsite, when possible.

If a paleontological resource is discovered during excavations, both the Project Paleontologist and the paleontological monitor(s) have the authority to halt or divert construction activity. In doing so, all ground-disturbing work within 50 feet of the discovery shall be halted, and the 50-foot buffer site secured by stakes and flagging. The paleontological monitor(s) will notify the construction supervisor and the Project Paleontologist of the discovery (if not onsite), who in turn shall notify the Proponent. The contact information is as follows:

Project Paleontologist:

Niranjala Kottachchi ECORP Consulting, Inc.

Telephone: 916-708-5330 Email: nkottachchi@ecorpconsulting.com

Proponent:

Cole Duncan, P.E.

Project Manager SWT Engineering Email: ctd@swteng.com

If no monitor is present onsite, the construction supervisor or supervisor responsible for the construction activity at the site of discovery shall be responsible for making the notifications.

The paleontological monitor(s) shall prepare daily logs that detail the types of activities and soils observed, in addition to any discoveries. They should be equipped with the necessary supplies in case of a fossil find that requires removal. Equipment and tools include a magnifying lens, flagging, survey stakes, and tools for fossil exploration and recovery, including utility/craft knives (such as X-ACTO knives), awls, brushes, picks, chisels, and shovels. Other essential tools for monitors include screens for wet/dry sieving sediment samples, chemical preservatives such as vinac or butvar, specimen containers such as vials and plastic bags, a GPS receiver, a field notebook, data recording forms, a digital camera, and a plaster kit.

If the fossil discovery is determined to be scientifically significant, fossil recovery will consist of:

1. assigning a unique locality number;

2. documenting the fossil locality with GPS and obtaining an estimate of the depth at which the fossil was found;

3. recording stratigraphic and lithologic descriptions;

4. documenting the fossil with photographs; and

5. completing a fossil locality form for each paleontological locality discovered.

mailto:nkottachchi@ecorpconsulting.com mailto:ctd@swteng.com

ECORP Consulting, Inc. 8 September 9, 2026

Specimen Processing

Screen-washed material will be transported to the ECORP laboratory, where it can be sorted to identify microfossils using a stereo-dissecting microscope. Larger fossils (such as vertebrates) recovered from the field will require the removal of the surrounding sedimentary matrix using various mechanical methods, including pneumatic air scribes, micro-sandblasters, and simple hand tools (such as hammers, chisels, brushes, and dental picks). Fossils will be stabilized and treated with preservatives and cleaned to the lowest taxonomic level possible, allowing for identification for curatorial purposes. A detailed taxonomic analysis will take place later in the museum, where the fossils will be curated. Details of the fossil specimens recovered will be incorporated into the Project’s final report. This final report of findings will be submitted along with field notes and photographs to the curation facility. In addition, a final report of findings, whether positive or negative, will be submitted to the County.

Curation Agreement

Prior to the start of construction, the Project Paleontologist will develop a curation agreement between the San Bernardino County Museum and the Project Owner/Developer, should significant paleontological resources be found during Project construction. Funding for the transfer and curation of resources at the institution must be paid for by the Project Owner/Developer.

Sincerely, Niranjala Kottachchi, M.S.

Principal Paleontologist

ECORP Consulting, Inc. 9 September 9, 2026

REFERENCES

Bortugno, E. J. and T. E. Spittler. Geologic Map of the San Bernardino Quadrangle, California, 1:250,000.

City of Beaumont. 2022. City of Beaumont Summit Station Specific Plan. Geology and Soils: Draft Environmental Impact Report. 28p.

Clifford, H. 2017. Paleontological Resource Sensitivity Assessment for the San Bernardino County Portion of the Beaumont Wastewater Treatment Plant Upgrade/Expansion and Brine Pipeline Project. 10p.

Lancaster, J. T., C. A. Hayhurst, and T. L. Bedrossian. 2012. Preliminary geologic map of the Quaternary surficial deposits in southern California. Palm Springs 30’ x 60’ quadrangle. In Geologic compilation of Quaternary surficial deposits in southern California. California Geological Survey Special Report 217: pl. 24 (scale 1:100,000).

Morton, D. M. and F. K. Miller. 2006. Geologic map of the San Bernardino and Santa Ana 30’ x 60’ quadrangles, California: U.S. Geological Survey Open-File Report 06-1217, scale 1:100,000.

Smith, B. F. and Associates, Inc. 2021. Paleontological Assessment for the Trammell Crow Beaumont Project.

City of Beaumont, County of Riverside, CA. 23p.

Society of Vertebrate Paleontology (SVP). 2010. Standard Procedures for the Assessment and Mitigation of Adverse Impacts to Paleontological Resources. 11 pp.

Webb Associates. 2022. Addendum No. 1 to the Initial Study and Mitigated Negative Declaration for the Beaumont Wastewater Treatment Pant Upgrade/Expansion and Brin Pipeline for the Mesa Lift Station and Force Main Project. 146p.

LIST OF APPENDICES

Appendix A – Maps

Appendix B – Qualifications

APPENDIX A

Maps

Map Date: 8/31/2026 Sources: ESRI, USGS

Lo ca tio n:

N

\2

6-

Sa n Ti m ot eo L an df ill U ni t

Ph as e

5- 2\

M

AP

S\ Lo ca tio n_ Vi ci ni ty \S an T im ot eo L

F Ln

V.

ap rx

S an

T im ot eo

L nV

(k ed w ar ds

/3 1/

Redlands (1996 p.r. 1999, NAD 83) CA 7.5-minute Topographic Quadrangle

US Geological Survey.

San Bernardino County, California

§8, T.02S, R.03W, SBBM

Latitude (NAD83): 34.011079° Longitude (NAD83): -117.213282° Watershed: Santa Ana (18070203)

I 0 1,000 2,000

Scale in Feet

2026-505 San Timoteo Sanitary Landfill Project

Figure 1. Project Location and Vicinity

Project Area - 47.98 ac.

Cypress Way

W Pilgrim

Rd

Refuse Rd

R e fu se

R d

R e f u s e R d

QPcQPc grMzgrMz

QQ

QQ

Map Date: 8/31/2026 Sources: Esri Imagery, Vantor (2024), California Department of Conservation - Geologic Atlas of California (2010)

Lo ca tio n:

N

\2

6-

Sa n Ti m ot eo L an df ill U ni t

Ph as e

5- 2\

M

AP

S\ So ils _a nd _G eo lo gy \S an T im ot eo S oi ls a nd

G eo

.a pr x

Sa n

Ti m ot eo

G eo lo gi c ke dw ar ds

/3 1/

Map Contents

Project Area - 47.98 ac.

Geology Types

Q - Alluvium, lake, playa, and terrace deposits;

unconsolidated and semi-consolidated

QPc - Pleistocene and/or Pliocene sandstone, shale, and gravels deposits; mostly loosely consolidated

I

0 800

Feet

2026-505 San Timoteo Sanitary Landfill Project

Figure 2. Geology Types

APPENDIX B

Qualifications

Niranjala Kottachchi Paleontology Task Manager

Ms. Niranjala Kottachchi is a geologist with experience in paleontology for more than 16 years (three with ECORP). She specializes in conducting record searches, field surveys, construction monitoring, and fossil preservation and identification in both a field and lab environment. Her skills include the preparation of plans and reports that identify, evaluate, and mitigate paleontological resource impacts in compliance with California Environmental Quality Act/National Environmental Policy Act (CEQA/NEPA) and Society of Vertebrate Paleontology (SVP) standards, and in compliance with various state and local agency standards.

Ms. Kottachchi has worked closely with all California institutes that conduct paleontological record searches and curation. Her project experience is wide-ranging, and includes urban development, transportation and energy infrastructure, renewable energy, communication, and waste management projects throughout California. Her most substantial work has been for Fresno State University, monitoring and supervising excavation and recovery of Pleistocene vertebrates at the Fairmead Landfill Fossil Site north of Madera, California. She has published scientific papers in paleontology and teaches geology part-time at two of the local community colleges.

Education

M.S., Earth Sciences, Carleton University, Ottawa, Canada

B.S., Earth Sciences, Carleton University, Ottawa, Canada

Registrations, Certifications, Permits, and Affiliations

Principal Investigator and Field Director on BLM California Paleontology Permits (CA-25-01P, exp 10/15/2027)

Orange County Certified Paleontologist

Society of Vertebrate Paleontology certified Paleontologist (#1365666, Exp. 12/31/2026)

Professional Experience

308 Sango Court Demolition Project, Santa Clara County – Pacific West Communities, Inc. (2022- Ongoing). Paleontologist who prepared the project scope and cost, as well as the Paleontological Resources Mitigation and Monitoring Plan.

Saxon Reservoir and Booster Station, Los Angeles County – Golden State Water Company (2022- 2023). Paleontologist who prepared paleontological resource memo based on record search and literature reviews.

Veteran Boulevard Project, Fresno County – PaleoWest, LLC (2022). Monitoring and reporting of excavations during the construction of the Veteran Boulevard Interchange at State Route 99.

Niranjala Kottachchi (Continued)

SR-210 Waterman Avenue Interchange Project, San Bernardino County – XP U.S. Services Inc. (2022).

Paleontologist who prepared successful proposal for paleontological services for the project.

Buena Vista Debris Basin Project, Santa Barbara County – County of Santa Barbara (2022).

Paleontologist who conducted a paleontological record search and preparation of the Geology section for an IS/MND report.

Upper Truckee River Restoration/Lake Tahoe Golf Course Reconfiguration Project, Placer County – State Parks and Tahoe Regional Planning Agency (2021-Ongoing). Paleontologist who prepared the Geology and Soils section for the EIR/EIS.

Pleasant Grove Boulevard Widening Project, Placer County – City of Roseville (2021-2024).

Paleontologist who prepared a paleontological resource memo based on record search and literature reviews.

Victorville Wellness Center Project, San Bernardino County – City of Victorville Development Department (2021-2024). Paleontologist who prepared the Paleontological Resource Mitigation and Monitoring Plan and coordinated and supervised paleontological field technician during project construction.

Countryview Project, Riverside County – WSI Land Holdings, LLC (2021-2023). Paleontologist who coordinated and supervised paleontological field technician during project construction.

Desert Quartzite Solar Project, Riverside County – EDF Renewables North America (2020-2021).

Paleontologist who monitored geotechnical activities.

Oberon Renewable Energy Project, Riverside County – EDF Renewables (2020). Paleontologist who surveyed and monitored geotechnical activities.

Stanton Energy Reliability Center Project, Orange County – Jacobs and California Energy Commission (2019-2020). Paleontologist who supervised paleontological monitors during construction activities, consulted with the client, managed schedule, site visits, and delivered monthly and final reports.

Carlsbad Energy Center Project, San Diego County – NRG Energy, Inc. (2017-2018). Paleontologist who supervised paleontological monitors during construction activities, consultations with the client, scheduling, site visits, compiled daily monitoring reports, and technical report writing.

Alamitos Energy Center Project, Los Angeles County – Applied Energy Services (2017-2018).

Paleontologist who supervised paleontological monitors during construction activities, consultations with the client, scheduling, site visits, compiling daily monitoring reports, and technical report writing.

Huntington Beach Energy Center Project, Orange County – Applied Energy Services (2017-2018).

Paleontologist who supervised paleontological monitors during construction activities, consultations with the client, scheduling, site visits, compiling daily monitoring reports, and technical report writing.

R E

S U

M

Darryl Dang Senior Technical Specialist

Senior Principal Professional

Staff Archaeologist and Paleontological Technician

Archaeologist/Paleontologist

Mr. Dang is a paleontological and archeological monitor. He has over 23 years of experience as a paleontological field technician and has monitored for numerous construction projects on both public and private lands. In particular, Mr. Dang has expertise in salvaging fossil resources, recording data, processing sediment samples for micro fossil analysis, and preparing fossils for analysis and display. Mr. Dang has also received cross training as an archaeologist. As such, he has served as an archaeological field monitor, performed archaeological surveys, and performed extended Phase I studies, Phase II testing and evaluations, and Data Recovery excavations.

EDUCATION/TRAINING

California State University Long Beach, 1987-1990 Saddleback Community College, Mission Viejo, California, 1984-1986 University of California, San Diego, 1983-1984 Identifying Human Bone, Riverside County Coroner and George Page Museum, 2002

EXPERTISE:

Paleontological monitoring and field surveys Salvage and preparation of fossil resources for analysis and display Processing sediment samples for micro fossil analysis Archaeological surveys and field monitoring Archaeological extended Phase I studies, Phase II testing and evaluations, and Data Recovery excavations

Years of Experience 23 years

Certifications 40-Hour HAZWOPER, No.

17040568

8-Hour HAZWOPER Refresher

8-Hour HAZWOPER Refresher

8-Hour HAZWOPER Refresher

S U

Professional Experience

Kleinfelder, San Diego, CA, From 08/2020 To Present

Archaeological/Paleontological Field Monitor Field monitor for construction projects on both public and private lands. Archaeological duties include Surveys; Construction monitoring; Phase II testing and evaluations; Data Recovery; Writing cultural resources constraints analyses. Paleontological duties include Construction monitoring;

Salvaging paleontological resources; Recording locality data; and Processing bulk sediment samples for microfossil analysis.

Garcia and Associates, Auburn, CA, From 01/2010 To 08/2020

Archaeological/Paleontological Field Monitor Field monitor for numerous construction projects on both public and private lands. Archaeological duties included Surveys; Construction monitoring; Extended Phase I studies; Phase II testing and evaluations; Data Recovery; Writing cultural resources constraints analyses. Paleontological duties included Surveys; Construction monitoring; Salvaging paleontological resources; Recording locality data; and Processing bulk sediment samples for microfossil analysis. Garcia and Associates was acquired by Kleinfelder, Inc.

in August, 2020.

Paleo Resource Consultants, Auburn, CA, From 06/2011 To 09/2011

Paleontological Field Monitor Field monitor for the CPV Sentinel Energy project in Desert Hot Springs, CA. Duties included Construction monitoring; Recording lithological and stratigraphic data; and Processing sediment samples for the presence of paleontological resources.

Bonterra Consulting, Santa Ana, CA, From 07/2008 To 10/2011 Archaeological/Paleontological Monitor Field monitor for construction projects. Archaeological duties included Surveys; Construction monitoring; Extended Phase I studies; Phase II testing and evaluations; and Data Recovery.

Paleontological duties included Surveys; Construction monitoring; Salvaging paleontological resources; and Recording locality data.

Tierra Environmental, San Diego, CA, From 12/2007 To 06/2008

Archaeological/Paleontological Monitor Field monitor for the Sea Terrace Park project in Dana Point, CA. Duties included Construction monitoring for cultural and paleontological resources; Salvaging paleontological resources;

Recording locality data; Processing sediment samples for microfossil analysis; Preparing fossil specimens for display.

Chambers Group, Santa Ana, CA, From 07/2005 To 11/2010

Archaeological/Paleontological Monitor Field monitor for numerous construction projects on private lands.

Archaeological duties included Construction monitoring. Paleontological duties included Construction monitoring;

Salvaging paleontological resources; and Recording locality data.

L&L Environmental, Corona and Redlands, CA, From 11/2000 To 11/2011

Archaeological/Paleontological Monitor Field monitor for numerous construction projects on private lands.

Archaeological duties included Surveys; Construction monitoring; Phase II testing and evaluations; and Data Recovery. Paleontological duties included Surveys; Construction monitoring; Salvaging paleontological resources;

Recording locality data; and…