32 Mauchly, Suite B Irvine, CA 92618 TEL: (949) 450-2100 Anaheim – Irvine – Ontario – San Diego – Torrance – San Jose www.GroupDelta.com
City of Fresno, Airports Department January 6, 2025 4995 E Clinton Way Proposal Number EN24-211
Fresno, California 93727-1525
Attention: Cristal De La Torre
Subject: Change Order Request No. 1
Additional Site Visit and Phase 2 Subsurface Investigation Proposed Aviation Academy at the Fresno Chandler Executive Airport 716 W. Kearny Boulevard, Fresno, California
Dear Ms. De La Torre,
Group Delta Consultants, Inc. (Group Delta) is very pleased to provide this Change Order Request Number 1 (CO1) to perform an additional site visit to complete the Asbestos and Lead- Based Paint (LBP) Survey and conduct a Phase 2 Subsurface Investigation for the City of Fresno, Airports Department (Client) at the Subject Property (Site). Our project understanding is based on communications and requests from Ms. De La Torre by email and telephone in November and December 2024.
PROJECT DESCRIPTION
Based on the information provided by Client , it is our understanding that the Site is being considered for a proposed lease of an aviation academy by the Fresno Unified School District (FUSD). Project consists of three new structures, a parking area, and a new canopy, to be constructed on the south side of the Fresno Chandler Executive Airport in Fresno, California.
SCOPE OF WORK
Group Delta understands the project includes the following Tasks:
Task 1 – Additional Site Visit – Asbestos and Lead-Based Paint Survey Group Delta scheduled, coordinated and performed an additional pre-renovation asbestos and lead based paint (LBP) inspection survey to portions of the site that were not accessible during our initial inspection.
Task 2 – Project Scoping Activities and Work Plan Preparation Following completion of the Phase I Environmental Site Assessment (ESA), in accordance with CCR Title 22, § 69104 and section 17213.1, subdivision (a), of the Education Code , Group Delta provided recommendations consistent with section 69108 to evaluate several sources for the City of Fresno, Airports Department January 6, 2025
Change Order Request Number 1 - Phase II Subsurface Investigation Page 2
potential release or presence of hazardous materials . The scoping of this effort was emailed to Client between December 6 and 13, 2024.
Group Delta’s proposed scope of services includes preparation of a subsurface investigation work plan, provided herein, and its implementation. This effort is summarized below:
Task 3 – Phase 2 Subsurface Investigation
Based on the results of the Phase I ES A and the Department of Toxic Substances Control (DTSC) Interim Guidance, Evaluation of School Sites with Potential Soil Contamination as a Result of Lead from LBP, Organochlorine Pesticides (OCPs) from Termiticides, and Polychlorinated Biphenyls (PCBs) dated June 2006 , Group Delta will perform subsurface soil sampling to address the identified recognized environmental conditions (RECs) and areas of concern (AOCs) associated with hazardous materials, petroleum products and other potential contaminants commonly found at similar airports and industrial sites.
Task 3A – Pre-Field Investigation Planning Activities
This task comprises planning meetings with C lient, marking boring locations in white paint, a notification to Underground Service Alert (USA) at least 48 hours prior to field activities, permitting activities, site access coordination, and preparation of a health and safety plan (HASP).
In addition, Group Delta will attempt to obtain additional documentation regarding the historical on-site underground storage tank (UST), including its former location, subsequent removal, and associated remedial activities.
Task 3B – Subsurface Soil and Soil Vapor Investigation
Group Delta proposes to conduct a soil and soil vapor investigation through the advancement of fifteen (15) total soil borings and eight (8) soil vapor probe locations:
• A geophysical survey will be completed to clear all boring locations to reduce the potential for damage to subsurface utilities.
• Each boring location will be cored using a concrete coring device to expose the underlying soils.
• Using hand augers and/or truck mounted direct push drill rigs, each boring will be advanced to depths ranging from three to ten feet. A photo Ionization detector (PID) will be utilized to screen soil samples retrieved from the borings for the potential presence of volatile organic compounds (VOCs). Field decisions will be made when selecting soil samples to be analyzed based on PID readings, visual and/or olfactory observations at various depths.
• Soil borings will be advanced at the following locations:
o REC1: If the former UST location is identified, two soil borings will be advanced to a depth of 10 feet below ground surface (bgs).
Two samples will be collected from each boring.
City of Fresno, Airports Department January 6, 2025
Change Order Request Number 1 - Phase II Subsurface Investigation Page 3
Samples will be analyzed for VOCs by EPA Method 8260B, Semi- Volatile Organic Compounds (SVOCs) by EPA Method 8270, T otal Petroleum Hydrocarbons (TPH ) by EPA Method 8015B, and CAM Metals by EPA Method 6010B/7471A. Soil samples collected for VOC analysis will be collected in the field in accordance with EPA Method 5035. o REC2: Two soil borings will be advanced on either side of the oil/water separator. Two samples will be collected from each boring.
Samples will be analyzed for VOCs by EPA Method 8260B, TPH by EPA Method 8015B, SVOCs by EPA Method 8270, and CAM Metals by EPA Method 6010B/7471A. Soil samples for laboratory analyses for VOCs will be collected in the field in accordance with EPA Method 5035. o REC3: Up to three soil borings will be advanced within the paint booth. Two samples will be collected from each boring.
Samples will be analyzed for VOCs by EPA Method 8260B, SVOCs by EPA Method 8270, TPH by EPA Method 8015B, and CAM Metals by EPA Method 6010B/7471A. Soil samples for laboratory analyses for VOCs will be collected in the field in accordance with EPA Method 5035. o OEC1: Soil samples will be collected using hand tools in accordance with the
Interim Guidance – Evaluation of School Sites with Potential Soil Contamination (DTSC, 2006) as follows:
Lead: Collect six surface (0 to 0.5 feet bgs) and six shallow (1.0 to 1.5 feet bgs) within two feet of the structure due to the presence of lead -based paint (LBP) detected on the hangar’s exterior.
• Analyze six surface soil samples for lead by EPA Method 6010. • If lead exceeds the hazardous waste criteria of 50 mg/kg, solubility testing (STLC and TCLP , if necessary ) will be conducted on up to four samples for disposal and handling purposes during
remediation or demolition.
• If lead exceeds 80 mg/kg, analyze the shallow soil samples. Organochlorine Pesticides (OCPs): Collect six surface (0 to 0.5 feet bgs) and six shallow (2.0 to 3.0 feet bgs) samples within two feet of the structure due to potential historic termiticide applications on the hangar’s exterior. • The laboratory will be instructed to composite three of the discrete surface soil samples from one side of the hangar and three from the other side of the hangar.
• A total of four samples will be anal yzed for OCPs by EPA Method 8081.
Polychlorinated Biphenyls (PCBs): Collect one surface (0 to 0.5 feet bgs) and one shallow (2.0 to 3.0 feet bgs) soil samples in areas of visible staining or within two feet of the telephone pole located adjacent to the hangar on the West Kerney Blvd due to the potential historic releases of former pole- mounted electrical transformers containing PCBs.
City of Fresno, Airports Department January 6, 2025
Change Order Request Number 1 - Phase II Subsurface Investigation Page 4
• Following soil sampling , permanent single and multi- depth soil vapor probes will be installed at depths ranging from 1, 5 to 10 feet bgs in eight (8) borings located inside of the hangar building. Soil vapor samples will be collected a minimum of 2 hours or up to 48 hours following installation of the temporary soil vapor probes using individual 6 -liter summa canisters. Soil vapor probe installation and sampling will be conducted in accordance with the methods and procedures provided in the Department of Toxic Substance Control’s (DTSC’s) Active Soil Gas Investigation Advisory dated July 2015, with updates. The soil vapor samples will be analyzed for VOCs by EPA Method 8260B.
Task 3C – Reporting and Consultation
Analytical results will be summarized in tables and incorporated into a letter report. The soil and soil vapor analytical results will be compared to applicable environmental screening levels to provide a preliminary screening analysis of onsite soils and soil vapor with figures delineating contamination, where appropriate. The letter report will include recommendations and conclusions based on the planned future use of the site. This Task also includes environmental consultation with Client to discuss the results and recommendations for future development activities.
ASSUMPTIONS
The following assumptions are part of this proposal:
o The environmental fieldwork will be completed in one mobilization and will consist of a maximum of two days of field exploration/sample collection. If additional mobilizations are required to complete the fieldwork, these services will be provided on a time and materials basis separate from the fees provided below.
o This estimate was prepared with consideration of the proposed development design, including the building’s size, and footprint. The location of subsurface utilities, depth of soil disturbing activities, and the anticipated quantity of soil export was not provided.
o A geophysical survey will be conducted to attempt to determine the location of subsurface features including utilities. In addition, Group Delta will use a hand auger to clear the upper five feet of the subsurface where most utilities are present. However, if a subsurface structure or utility is damaged during site assessment, Group Delta will not be responsible for the costs to repair the damage or any disruption to the operation of the businesses affected. o If extensive clay intervals are present in the subsurface at the Site, some or all of the soil vapor probes may not be able to provide viable soil vapor samples for analysis.
o This investigation is limited to the constituents indicated and is not intended to identify all potential constituents. Our conclusions will be based on this information and on the environmental regulations in force and effect at the time of the investigation.
City of Fresno, Airports Department January 6, 2025
Change Order Request Number 1 - Phase II Subsurface Investigation Page 5
o Client will coordinate site access with the property owner and tenants and the entire Site will be accessible at the same time for the site reconnaissance and subsurface exploration portions of the scope of work.
o Other than boring permits included in our scope of work, other permits are not required for completing our proposed scope of work. o Site reconnaissance and the subsurface exploration program can be completed on weekdays (Monday – Friday) between the hours of 7:00am and 6:00pm.
o We assume that site soils are not impacted and can be disposed of through a soil recycler as non -hazardous waste. If impacted soils are encountered, we will notify you for further direction. Disposal of impacted soils may result in additional waste management and disposal costs.
o The project is not subject to prevailing wages or project labor agreement requirements.
o Group Delta will not be responsible for costs associated with delays, disruptions, or interferences caused by the owner.
SCHEDULE
We are prepared to start work on Task 3A immediately following receipt of your written authorization to proceed. The pre-field activities will take up to three weeks to complete and the field work will be completed in two days. The report is anticipated to be completed approximately three weeks following receipt of ALL laboratory analytical results.
FEES
We propose to perform the scope of work presented in this proposal in accordance with the fees presented in Table 1.
Table 1: Fees
Tasks Cost
Task 1 – Additional Site Visit for Asbestos and Lead Survey $3,350 Task 2 – Project Scoping Activities and Work Plan Preparation $4,000 Task 3A – Pre-Field Investigation Planning Activities $6,850 Task 3B – Subsurface Soil and Soil Vapor Investigation $44,300 Task 3C – Reporting and Consultation $14,500
Total $73,000
The above fee estimate cover s services provided through the completion of the Subsurface Investigation Report. This cost also includes approximately three hours per task for project management, coordination and up to two client meetings to discuss the results and plans for next steps, if necessary. We will not exceed these fees unless we encounter significant unexpected problems, or change of scope, in that event, we will discuss the situation with you City of Fresno, Airports Department January 6, 2025
Change Order Request Number 1 - Phase II Subsurface Investigation Page 6
before incurring any additional cost. Supplemental post- report services will be provided, as needed, on a time-and-materials basis per the attached fee schedule.
STAFFING
The following key staff will be assigned to this project. Each of the key staff members has extensive technical experience on similar projects.
Personnel Role
Ryan Seelbach Project Manager, Associate Geologist
Kevin Hall Project Scientist
Mike Cassidy Professional Geologist
CONCLUDING REMARKS
We look forward to being your consultant on this project. Please feel free to call us if you have any questions on the contents of this proposal.
If you accept the terms of this proposal and you wish us to perform the proposed services, please document your authorization to proceed by issuing a written authorization.
Sincerely,
GROUP DELTA CONSULTANTS, INC.
Ryan Seelbach, QSD, CPESC
Project Manager
The undersigned, being duly authorized, hereby accepts and specifically agrees to be bound by the above document and exhibits attached hereto and authorizes Group Delta Consultants, Inc. to undertake the items of work described in the above document.