Proposal for Twining, Inc., (available in the City Clerk's Reading File) — Santa Clarita City Council, April 22, 2025

CITY OF SANTA CLARITA

PROPOSAL TO PROVIDE
2024‐25 Overlay Slurry Seal Program ‐ Materials Testing and Inspection
PROPOSAL # CIP‐24‐25‐M0157M
March 7, 2025
Twining | City of Santa Clarita 2

TABLE OF CONTENTS

1. Introduction - Cover Letter ................................................. 3

2. Qualifications of Firm and Assigned Staff ....................... 5

3. Work Statement ...............................................................16

4. Schedule ...........................................................................18

5. Sub-Consultants ...............................................................20 Twining | City of Santa Clarita 3

1. INTRODUCTION - COVER
LETTER
March 7, 2025
Proposal No. 25-0246
Michele Arima
City of Santa Clarita
[email protected]
RE: 2024‐25 Overlay Slurry Seal Program ‐ Materials Testing and Inspection Dear Michele,
Twining, Inc. (Twining) is pleased to present our proposal and qualifications for the 2024-2025 Annual Overlay Projects to the City of Santa Clarita (City). We understand that the City is seeking a well qualified consultant, famliar with Materials Testing and Inspection for Overlay and Slurry Seal Projects. The City’s objectives include the collection of material samples for testing as well as project inspection services.

We also understand that our work must comply with Materials Testing and inspection as per the project plans and specifications, the City’s Quality Assurance Program (using CT methods), the latest edition of Caltrans Construction Manual, and Public Works Construction Green Book. We will work closely with the City’s Project Manager and staff to successfully complete the project and protect the interest of the City. » Our History and Knowledge of the City
Twining has been the City’s trusted advisor for over a decade. We are honored to have a strong partnership and committed to providing the high-quality work you’ve come to expect from us. We are aware that time is of the essence and that the selected consultant will be expected to start providing services as soon as the City contract is executed. We are ready and confident that we can hit the ground running, meeting the project goals effectively and efficiently.

Our history of working with the City points to other benefits to selecting Twining as the consultant for this project. We continue to find ways to save the City time and money that benefit the community you serve. The City is an important client to us and is a critical part of our business. We strive to strengthen our partnership with the City for these projects and beyond.

Our continuous collaboration with the City on these projects and beyond has saved the City hundreds of thousands of dollars over the better part of the past decade. We understand that this contract has core projects as well as alternate options.
1879 Portola Road, Suite G
Ventura CA 93003
Tel 805.644.5100
Fax 562.426.6424
Twining | City of Santa Clarita 4
As the City’s staff make-up has evolved we have continued to maintain our great working relationship and provide continuity of service during this transition within your internal operations. Twining is proud to consider ourselves part of your City’s public works family and commits to keeping your current project on track and within or under budget as we have done in the past. » We Understand On-Call Contracts
Twining is highly experienced with on-call services contracts. Maintaining a large resource pool of qualified individuals to respond in a timely manner has been critical to our successful delivery of more than thirty five (35) projects involving Pavement Engineering, Materials Testing, and Special Inspections services for numerous municipalities and State governments this past year alone. Our on-call materials testing experience includes local agencies like the Cities of Thousand Oaks, Agoura Hills, Santa Clarita and County of Ventura. Our Ventura office is located roughly 30 miles from the City of Simi Valley. This proximity helps to ensure our rapid response to all your project needs. » Depth of Inspection Resources
Twining employs more than 180 inspectors and technicians throughout the state, more than 80% of whom hold multiple inspection certifications. Our field staff is well versed in the Caltrans Local Assistance Procedures Manual, Caltrans Construction Manual, and the Greenbook Standard Specifications for Public Works Construction.

Twining appreciates the opportunity to submit our qualifications to the City. Our familiarity with on-call municipal contracts, proven project management approach, and deep bench of inspection resources make us the ideal candidate to continue serving the City. This proposal offer is valid for at least ninety (120) days. Should you have any questions or comments, don’t hesitate to contact Jeff Tawakoli, Ventura Branch Manager, by phone at 805.827.0742 (mobile) or by email at [email protected].

Sincerely,
Twining, Inc.

Jeff Tawakoli, PE Linas Vitkus, PE, GE
Ventura Branch Manager President and Chief Operating Officer (Authorized to contractually bind the firm)

Twining | City of Santa Clarita 5

2. QUALIFICATIONS OF FIRM AND
ASSIGNED STAFF
Firm Introduction
Twining’s legacy dates back more than 127 years. What started as a family business in 1898 has evolved into one of California’s largest service providers of geotechnical engineering design, materials testing, and construction inspection services. Highly regarded by state and local agencies, developers, contractors, consultants, and industry for providing high-quality services that are reliable, timely, and compliant, Twining has been a central part of some of California’s most regionally significant construction projects. The expertise and capabilities of Twining in geotechnical and many civil engineering disciplines, including testing of asphalt, soils, steel, and various construction materials, complement our services for the asphalt construction industry.

Twining has developed a strong reputation by providing sound engineering, testing, and inspection services on every project we undertake. We earned this reputation knowing that the true measure of our performance rests in the satisfaction of our clients. We approach each project with the understanding that we are evaluated on the safety and durability of the structures and pavements we test and inspect.

We employ some of the industry’s most well-known construction experts, including asphalt and concrete experts who perform research as well as consult with regulatory agencies to shape the future of construction standard practices. Our geotechnical team leaders are licensed and highly qualified with experience in geotechnical design, analysis, and construction support. In addition to our engineers’ highly technical consulting services, we can also provide construction material testing and inspection services. Our engineers offer routine training to our field soil technicians to continuously improve and reinforce their skills related to field testing.

Additionally, experienced inspectors and laboratory technicians can provide field observation and testing to provide immediate compaction data to the Contractor, thus allowing for efficient and accelerated progress of the schedule.

Years in Business
127
Office Location
1879 Portola Road, Suite G
Ventura CA, 93003
Inspectors and Technicians
180+
Professional Services
» Geotechnical Engineering
» Nondestructive Examination
» Materials Testing Laboratory
» Vibration Monitoring
» Stormwater Site Monitoring and SWPPP
» Forensic Evaluation of Existing
Structures
» Applied Research and Materials
Engineering
» Concrete Technology & Concrete Insight
» Concrete for Pavements & Infrastructure
» Asphalt Pavement Engineering Design
» Construction Quality Assurance
Programs
» Mobile Laboratories
» Roofing and Waterproofing Inspection
» Plan Review and Plant Inspection
» Building Material Evaluations &
Specialized Testing
» Petrographic Laboratory
Twining | City of Santa Clarita 6

2. Qualifications of Firm and Assigned Staff
Materials Testing Laboratory
Twining provides fast, reliable test results our clients can count on and has been at the forefront of construction
materials testing for over a century. Our network of state- of-the-art laboratories, complemented by our fleet of
mobile laboratories, allows us to provide in-house testing for projects throughout California.

Twining subscribes to the most stringent inspection
and certification requirements in the industry. We are
recognized by agencies including Caltrans, Division of
the State Architect (DSA), American Association of State Highway and Transportation Officials (AASHTO), Cement
and Concrete Reference Laboratory (CCRL), International Accreditation Service (IAS), and U.S. Army Corps of
Engineers, along with numerous cities and counties as a certified geotechnical, asphalt paving, materials testing, and inspection laboratory.

Our laboratory is capable of testing virtually any structural material utilized in modern construction. Testing is
performed by trained and certified technicians per
relevant American Society for Testing and Materials
(ASTM), American Association of State Highway and
Transportation Officials (AASHTO), or California Test
Methods (CTM). In addition, custom or modified test
procedures can be performed upon request. Some of our
testing equipment and capabilities include:
» Up to 600,000-pound universal test machines
» Charpy V Notch test apparatus
» Rockwell hardness testing machines
» Welding procedure qualification record and welder
qualification testing
» Full range of concrete masonry unit block testing
» Facilities for chemical and physical analysis of
cementitious materials, chloride permeability, and a vast range of specialized tests
Twining's laboratory is accredited/certified
by the State of California and under the
management of a California Registered
Professional Engineer to provide materials
testing, including for federal aid projects.

Twining | City of Santa Clarita 7

2. Qualifications of Firm and Assigned Staff
Infrastructure Construction Expertise
With California’s aging infrastructure and continued
urban growth, our cities and counties are faced with
unique challenges. Never has it been more critical to
maximize the value of each public works dollar spent on capital improvement than today. The quality assurance
programs that Twining has established for public agencies throughout the state emphasize the most cost-effective
practices utilizing industry best practices. Whether it is a major CIP project, bridge or roadway improvement,
or underground utility work, Twining has the requisite
expertise and capabilities to effectively establish and maintain a quality assurance program that is in strict
compliance with the local assistance procedures manual
(LAPM) as well as state and federal mandates.

Twining provides the following services for local agencies:
» Initial engineering design and evaluation
» Specification development and review
» Materials review and verification for acceptance
» Public works inspection
» Source inspection
» Acceptance laboratory testing and evaluation
» Federal compliance
» Final quality assurance report and project closeout
Twining’s involvement with the most cutting edge
materials technologies enables us to assist project
teams with the evaluation of construction products and
determining their suitability for use. Twining has assisted construction managers, structural design engineers,
and owners in developing high-strength concrete
mixes utilizing low carbon emission materials, recycled asphalt pavement structural designs, and various other
cementitious, geotechnical, and sustainable asphalt
pavement components that utilize renewable materials.

Twining is uniquely positioned to provide quality
assurance programs from start to finish. Through our
partnerships with Caltrans and various universities,
we have knowledge of proven technological advances
in construction that we can pass on to our clients and
incorporate into their projects as appropriate. We routinely contribute to the American Public Works Association
by presenting technical sessions related to some of the newest technological advances. Whether it involves rapid strength concrete, warm mix asphalt, high volume fly
ash mixes to reduce greenhouse gases, or 100 percent
recycled materials, Twining can provide the proper
solution for your project.

Innovative Pavement Design Solutions
Twining’s experts have been providing pavement
engineering and materials evaluation services on flexible pavement projects for decades. Our highly specialized
and dedicated team of experts provides comprehensive
pavement engineering services that utilize the newest
pavement rehabilitation technologies to effectively deliver our clients the service life they expect of their pavements at a construction cost that may be less than traditional methods.

Twining is closely involved with hot mix asphalt
industry associations and government agencies that
keep our engineers on the pulse of new and upcoming
technologies. While we have a comprehensive
understanding of traditional methods and designs, we do not automatically suggest the same textbook solutions to all our clients. We individualize our recommendations to include new flexible pavement materials that can be used most effectively and economically. Whether it is a highly- traveled arterial roadway that requires high stability in intersections to prevent pavement rutting or a residential collector that the residents expect to be as quiet as
possible, Twining has the solution.

Twining routinely assesses current pavement conditions
and identifies the causes of pavement distress. Using
the Falling Weight Deflectometer (FWD), coring, ground
penetrating radar (GPR), and dynamic cone penetrometer
testing, we are able to assess subgrade conditions and
determine the load-carrying capacity of in-place pavement.

Our efforts can determine the remaining service life
of pavement and identify options for rehabilitation.

Supported by Twining’s sophisticated laboratories, our
expert staff has a deep knowledge of asphalt concrete
mixtures. We routinely test and inspect hot mix asphalt designs consisting of the following materials:
» Polymer Modified Binders
» Rubberized Hot Mix Asphalt
» Warm Mix Asphalt Research and Development
» Hot Mix Asphalt Using High Amounts of Recycled
Asphalt Concrete
» FAA Marshall designs
» Superpave Designs
We perform production quality and strength and mix for:
» Asphalt Content
» Gradation
» Stability
» Hamburg Wheel Track
» Project Specific Volumetrics
Twining | City of Santa Clarita 8

2. Qualifications of Firm and Assigned Staff
The proper structural section design for flexible pavement as well as the asphalt concrete mixture type is crucial to its performance and longevity. Poor design can result in early failures, substandard performance and repairs that quickly become costly.

We are committed to helping agencies ensure the
design and implement of their pavement projects meets
relevant specifications for their jurisdiction . Our extensive experience providing quality assurance and quality control services in the field gives us unique insight and allows us to provide correction recommendations that can be
implemented and are reliable should the need arise.

Twining professionals are members of the American
Public Works Association, the Asphalt Pavement
Association, the Rubber Pavements Association, the
National Asphalt Pavement Association, and the Caltrans expert task group on flexible pavements. They have
vast knowledge of hot mix asphalt materials and the
constraints during production, as well as experience
managing comprehensive quality assurance and quality
control programs.

Pavement Treatment and Maintenance
Twining and its engineers and specialists have been
involved with the design, development, quality assurance, and performance evaluation of asphalt pavements for
over 20 years. The firm has partnered with Caltrans in
the evaluation of the rubber pavements pilot warranty
program conducted back in 2001 and has consulted
with scores of California municipalities on their annual ARHM overlay program since 1998. Our team has in-depth
experience with the following pavement treatment types:

Preventative Maintenance
» Fog Seal
» Chip Seal (Rap Chips)
» Scrub Seals
» Slurry Seals
» Microsurfacing
» Cape Seals
» Bonded Wearing Course
» Micromilling
» Asphalt Rubber Hot Mix-Gap Graded (ARHHM-GG)
» Overlays
» Prep-Work (Digouts)
Rehabilitation
» Cold In-Place Recycling
» Cold Central Plant Recycling
Reconstruction
» Full-Depth Reclamation
» Lime Stabilization
Pavement Maintenance Capabilities
» Pavement Evaluation and Design Services for
Pavements
» Falling Weight Deflection Testing, Geotechnical
Pavement Engineering, and Analysis
» Project Specification Development and Pavement Repair Plan Preparation
» Pre-Construction Bid Assistance with Technical RFIs
» Submittal Review, Quality Assurance Acceptance, and
Technical Quality Review
» Pavement Placement Inspection during Construction
» Binder Plant Inspection to Verify Reaction Times, Use of Crumb Rubber, Temperatures, Gradations, Etc.
» Placement Compaction Testing
» Laboratory Materials And Performance Predictive
Testing

Twining | City of Santa Clarita 9

2. Qualifications of Firm and Assigned Staff
Since 2008, Twining has been providing material testing, engineering, and inspections services for the County of Ventura. We enjoy working on projects that shape the future of the County, and the municipalities within it. We have a strong relationship with the County and its local agencies, having worked on various projects for cities, such as the City of Oxnard, Thousand Oaks, Simi Valley, and others. Some of our recent project expe- riences includes:
» Bus Pullout on Hwy 33 South of Loma Drive
» Casitas Vista Road
» CRT Material Testing & Inspection Services
» Lockwood Valley Road (West)
» Norway Track Pavement Resurfacing
» Ojai/West Ventura Areas Resurfacing - Various Streets Ventura County » Pavement Resurfacing East Oak Park Area RD12-13
» Pavement Resurfacing Nyland Acres
» Rice Road Bike Lanes
» Rose Ave at Central Ave Pedestrian Improvements
» Sulphur Mountain Road Pavement Resurfacing
» Ventura College Building G Reroofing Project
» West Oak Park Pavement Rehab
» Yerba Buena Road South Resurfacing
County of Ventura
As-Needed Material Testing, Engineering, and
Inspection Services
Public Agency
County of Ventura
Location
Ventura County, CA
Year Completed
2020
Reference
Joshua Patricio
805.654.2054
[email protected]
Project Type
Street Rehabilitation
Twining Staff
Amir Ghavibazoo, PhD
Jeff Tawakoli, PE
Eddie Perez

Twining | City of Santa Clarita 10

2. Qualifications of Firm and Assigned Staff
The City of Simi Valley conducts an annual major and minor street rehabilitation program on many of their arterial and residential streets. The project consisted of residential pavement rehabilitation consisting of a conventional hot mix asphalt overlay, curb and gutter repair, and a type I slurry seal on select residential streets.

Twining was retained as the quality assurance laboratory for the city and provided placement inspection, field compaction testing, batch plant inspection, laboratory testing, and slurry seal sampling and testing.

City of Simi Valley
Annual Major Streets Pavement Program
Public Agency Name
City of Simi Valley
Location
Simi Valley, CA
Year Completed
2019
Reference
Fuad Shamot
805.583.6788
[email protected]
Project Type
Street Rehabilitation
Twining Staff
Amir Ghavibazoo, PhD
Jeff Tawakoli, PE
Eddie Perez

Twining | City of Santa Clarita 11

2. Qualifications of Firm and Assigned Staff
The City of Thousand Oaks is responsible for maintaining approximately 380 miles of streets, and is a leader in exploring the use of innovative pavements with emphasis towards utilizing recycled crumb rubber in asphalt concrete pavements.

Since 2010, Thousand Oaks has engaged the services of Twining to assist in review and revision of the community’s pavement rehabilitation specifications, perform materials design studies, implement quality assurance programs, perform construction inspection and testing, and perform pavement destructive testing and assist with pavement deflection testing for future pavement designs.

The City used Terminal Blend Rubberized Emulsion Aggregate Slurry Seal (REAS), using black rock source. The black rock will help the slurry seal to retain its black color for a longer period of time and the rubberized emulsion will add to the durability of the slurry seal product.

Twining has also provided annual materials certifications and labor compliance interviews throughout the projects.

City of Thousand Oaks
Annual Rubberized Asphalt Concrete Rehab
Public Agency
City of Thousand Oaks
Location
Thousand Oaks, CA
Year Completed
Ongoing
Reference
Nader Heydari
(805) 449-2100
[email protected]
Project Type
Street Rehabilitation
Twining Staff
Amir Ghavibazoo, PhD
Jeff Tawakoli, PE
Eddie Perez

Twining | City of Santa Clarita 12

2. Qualifications of Firm and Assigned Staff
Organization Chart
Project Manager/
Engineering Oversight
Amir Ghavibazoo, PhD
Quality Control Manager/
Engineer
Jeff Tawakoli, PE
Laboratory Technicians
Laboratory Manager
Sean Bautista*
Lead Public Works Inspector
Eddie Perez
Additional Public Works
Inspectors
Alexandra Brown*
Jack Gains*
Resumes available upon request
Firm’s principal contact
*
Over 180 Special Inspectors
Twining | City of Santa Clarita 13

2. Qualifications of Firm and Assigned Staff
City of Santa Clarita, Annual Overlay & Slurry Seal
Each year, streets are evaluated and identified for their need for rehabilitation or maintenance treatments. These projects include asphalt overlay, micro-surfacing, and slurry seal treatments to streets in various areas of the City. Twining performed quality assurance testing and inspection, Amir serves as project manager for this job, coordinating all required testing and inspection and reviewing test results.

City of Thousand Oaks, Annual Pavement Overlay and Slurry Since 2010, Thousand Oaks has engaged the services of Twining to assist in review and revision of the community’s pavement rehabilitation specifications, perform materials design studies, implement quality assurance programs, perform construction inspection and testing, and perform pavement destructive testing and assist with pavement deflection testing for future pavement designs. Amir serves as the Project Manager. He coordinates all required testing and inspection and reviews test results.

County of Ventura, Route 118 (07-296704)
Twining performed quality control testing on route 118 in Ventura County. Amir served as project manager and project engineer. He was responsible for the oversight of all daily sampling and testing, as well as providing technical comments in regard to possible issues, and suggesting a solution to the client based on the test results.

City of Simi Valley, Erringer Road at Cochran Street
This project consisted of the construction of a northbound right turn lane on Erringer Road at Cochran Street. Twining performed surface and subsurface soils investigation, testing, evaluation, geotechnical inspection, materials testing for conventional and rubberized asphalt concrete pavement, structural section evaluations for pavement defection testing, and laboratory testing services. Amir served as the pavement engineer. He reviewed the test data and prepared recommendations to the City.

Relevant Experience
Years of Experience
11 Education
PhD, Civil and Environmental
Engineering, North Dakota
State University
MS, Railways Engineering,
Iran University of Science and
Technology, Tehran, Iran
BS, Industrial Engineering,
University of Technology,
Tehran, Iran
Dr. Amir Ghavibazoo is Twining’s Director of Asphalt Engineering and Pavement Design and has served as project manager for this contract for more than six years. He directs and works on pavement design, highway design, engineering specifications, and consulting services. Amir’s graduate studies included Pavement Management Systems (MicroPaver), pavement evaluation and pavement rehabilitation strategies. He works closely with cities statewide to develop unique and specialized mix designs, pavement construction inspections, and pavement design solutions. Amir’s specialized knowledge allows our firm to offer creative and unique pavement solutions to fit any budget and other goals.

Professional Summary
Amir Ghavibazoo, PhD
Project Manager/Engineering Oversight
Twining | City of Santa Clarita 14

2. Qualifications of Firm and Assigned Staff
City of Santa Clarita, Annual Overlay & Slurry Seal (Multiple Years) Each year, streets are evaluated and identified for their need for rehabilitation or maintenance treatments. These projects include asphalt overlay, micro-surfacing, and slurry seal treatments to streets in various areas of the City. Twining performs quality assurance testing and inspection, Jeff serves as quality control manager throughout this program, providing engineering support out of our local Ventura office.

City of Calabasas, Lost Hills Road Interchange Improvement Project This $25 million project included the expansion of the existing Lost Hills Road/US- 101 overcrossing from two lanes to five lanes. Jeff served as the project manager, overseeing the delivery of all of our services, dispatching inspectors, reviewing all reports, and acting as the single point of contact for the project team.

County of Ventura, Sespe Street Bike Lanes
This project involved pavement widening for installation of 1.96 Class II bike lane miles along Sespe Street from South Mountain Road to Riverside Avenue in the Bardsdale area. This project was part of an effort to provide safe roadways for multiple modes of traffic and a continuous effort to construct bike lanes to promote and provide connectivity to regional routes. Twining provided material testing and inspection of asphalt and soils. Jeff served as Project Manager.

City of Simi Valley, Erringer Road at Cochran Street
This project consisted of the construction of a northbound right turn lane on Erringer Road at Cochran Street. Twining performed surface and subsurface soils investigation, testing, evaluation, geotechnical inspection, materials testing for conventional and rubberized asphalt concrete pavement, structural section evaluations for pavement deflection testing, and laboratory testing services. Jeff served as the Project Manager for this project, providing oversight of materials testing for both laboratory and field services. He was responsible for coordinating schedules, managing budgets, reviewing inspection in the field, reviewing and approving all field inspection.

Relevant Experience
Years of Experience
37 Education
BS, Civil Engineering,
University of Utah
Current Registrations/
Certifications/Specialized
Training
Registered Professional
Engineer (Civil), State of
California (No. 51883)
Registered Professional
Engineer (Civil), State of
Nevada (No. 10869)
Registered Professional
Engineer (Civil), State of Utah
(No. 176290)
ICC Spray Applied Fire
Proofing
ICC Reinforced Concrete
ICC Structural Masonry
Professional Affiliations
American Society of Civil
Engineers (ASCE)
Jeff Tawakoli, PE, is a professional engineer with over 37 years of experience in geotechnical and construction materials engineering. He has served as a local resource in similar capacity on this contract for the past several years. Jeff’s areas of expertise includes subsurface investigation, engineering analysis, preparation of soils reports, building and roadway inspection and engineering, and project management. He has provided geotechnical engineering support for public works programs, industrial and residential developments, military facilities, roadways, and mid-rise buildings.

Professional Summary
Jeff Tawakoli, PE
Quality Control Manager/Engineer
Twining | City of Santa Clarita 15

2. Qualifications of Firm and Assigned Staff
City of Santa Clarita, Annual Overlay & Slurry Seal (Multiple Years) Twining is contracted by the City to perform construction materials testing and inspection services for the annual overlay and slurry seal program. Twining performs construction materials testing and inspection at various project sites and the batch plant. Our firm performs mix design verification and laboratory testing. Twining also assists the City in performing slurry seal placement inspection and testing. Eddie serves as the lead public works inspector. He attends construction progress meetings, and review and ensures adherence to plans and specifications.

City of Simi Valley, Annual Pavement Rehabilitation
The City of Simi Valley conducts an annual major and minor street rehabilitation program on many of their arterial and residential streets. The project consisted of residential pavement rehabilitation consisting of a conventional hot mix asphalt overlay, curb and gutter repair, and a type I slurry seal on select residential streets.

Eddie served as an inspector for this project. He tested the hot mix asphalt to ensure compliance with standards.

City of Thousand Oaks, Annual Overlay Program
The City of Thousand Oaks is responsible for maintaining approximately 380 miles of streets and is a leader in exploring the use of innovative pavements with emphasis towards utilizing recycled crumb rubber in asphalt concrete pavements. Since 2010, the City has engaged the services of Twining to assist in review and revision of the community’s pavement rehabilitation specifications, perform materials design studies, implement quality assurance programs, perform construction inspection and testing, and perform pavement destructive testing and assist with pavement deflection testing for future pavement designs. Eddie serves as the City’s construction manager, attending weekly construction progress meeting with City officials and the contractor(s). He reviews and ensures adherence to construction plans and project specifications. Eddie reviews inspector’s daily field reports, enforces traffic control requirements, performs scheduling of field/plant inspection, coordinates material sampling/testing, collects all load tix/invoices and verifies and logs all bid quantities.

Relevant Experience
Years of Experience
14 Current Registrations/
Certifications/Specialized
Training
CalTrans 125 ADMIX, 125
AGG, 125 BIT, 125 CEM, 125
GEN, 125 HMA
OSHA 10-hour Construction
Safety and Health
Eddie Perez brings over 14 years of technical expertise as a public works construction and quality assurance manager. He serves as the City’s eyes and ears on public works construction. He routinely attends construction progress meeting with City officials and the contractors. He reviews and insures adherence to construction plans and project specifications. His experience encompasses all aspects of public works construction with special emphasis on roadway projects that include utility work ADA ramp remove and replace, street signal loop and signal install and roadway striping in addition to asphalt and concrete paving. He is intimately familiar with Caltrans and Green Book Standards and serves as an extension of City resources.

Professional Summary
Eddie Perez
Lead Public Works Inspector
Twining | City of Santa Clarita 16
Understanding
Twining understands that the City of Santa Clarita requires Quality Assurance Construction Materials Testing and
Inspection Services to support its overlay programs. Our role will be to provide comprehensive inspection and
testing services in accordance with the City’s Quality
Assurance Program, ensuring that all materials and
construction activities meet the applicable standards,
including.
• City of Santa Clarita Quality Assurance Program (QAP) • Caltrans Construction Manual, current edition
• CALOSHA Construction Safety Orders, current edition
• Standard Specifications for Public Works (Greenbook), current edition
• Standard Plans for Public Works, current edition
• Project-specific plans, specifications, and attachments in the City’s RFP
Twining recognizes that our responsibilities will include on-site inspection, field and laboratory testing of
asphalt and concrete materials, compliance verification, documentation, and coordination with all project
stakeholders. Our proposed work plan ensures that all
project objectives are met while maintaining compliance with California Testing Methods (CTM) and industry best practices.

Task 1: Engineering Support During Overlay
Project
Subtask 1: On-call Support to the City’ s Project Manager Output:
• Twining’s Project Manager and Lead Public Works
Inspector will be available from project inception
through completion via phone, email, and in-person
meetings to provide timely responses to City inquiries. • Support will include technical guidance, problem
resolution, and procedural recommendations
throughout the project.

Subtask 2: Materials Submittal Review
Output:
• Twining will conduct timely and thorough reviews
of contractor submittals, ensuring compliance with
project plans, specifications, and applicable standards. • The City’s Project Manager will receive comprehensive feedback and approvals to facilitate smooth project
execution.

Subtask 3: Attendance at Project Meetings
Output:
• Twining’s Project Manager and Senior Field Inspector
will attend all requested meetings to provide
updates, discuss testing and inspection findings, and
coordinate with the City’s project team.

Subtask 4: Review of Inspection and Testing Results
Output:
• Twining will ensure that all laboratory and field testing is scheduled promptly, with results reviewed and
submitted in a timely manner.
• Reports will highlight any non-compliant results, with accompanying recommendations and corrective
actions provided upon request or as necessary.

Task 2: Field Support During Overlay Project

3. WORK STATEMENT

Twining | City of Santa Clarita 17

3. Work Statement
Subtask 1: Public Works Inspection Services
Output:
• Twining’s Public Works Inspectors will provide
supplemental support to the City’s inspection team
throughout the project.
• Inspections will include staging areas, traffic control, contractor housekeeping, and compliance with daily
construction activities.

Subtask 2: Asphalt Inspection Services
Output:
• Twining will conduct laydown inspection and
compaction testing throughout paving operations.
• If the City requests observation of grinding operations, Twining will provide personnel to monitor and
document activities in accordance with project
specifications.
• Plant inspection will be performed throughout paving
operations, ensuring asphalt production meets
Greenbook and Caltrans standards.
• Asphalt samples will be collected from both the plant and field for laboratory testing.

Subtask 3: Asphalt Coring and Testing
Output:
• Twining will provide an experienced technician to core asphalt pavement at a frequency of one core per 250
tons.
• The cores will be transported to Twining’s laboratory for testing to verify asphalt density and compaction
compliance.

Task 3: Materials Testing During Overlay
Project
Subtask 1: Laboratory Testing of Asphalt Materials
Output:
• Twining’s certified laboratory will conduct asphalt
content, gradation, moisture content, density,
stability, air voids, and sand equivalency testing to
confirm compliance with project specifications.
• Acceptance criteria will be based on key parameters,
including asphalt content, gradation, and stability
results.
• Daily core testing will be performed to ensure
compliance with compaction requirements.

Task 4: Quality Assurance Documentation
and Reporting
Subtask 1: Daily and Final QA Reporting
Output:
• Twining’s Project Manager will review daily field and laboratory activities and prepare detailed inspection
reports.
• Reports will document test results, frequencies,
retests (if necessary), and conformance assessments.
• Any failing materials or test results will be immediately reported to the City’s Project Manager with
recommendations for corrective action.
• Twining will ensure that all materials accepted based on a Certificate of Compliance (COC) are referenced
in daily inspection reports.
• Upon project completion, a final Quality Assurance
Report will be submitted, summarizing all testing,
inspections, and conformance evaluations for the
City’s records.

Commitment to Compliance and
Coordination
Twining recognizes the importance of proactive
communication and coordination with all project
stakeholders, including the City’ s Project Manager,
contractor, utility companies, design engineer, and public works inspectors. We will work closely with the City to ensure timely issue resolution and compliance with
project specifications.

Additionally, Twining will utilize the City’ s designated Construction Management Software (Eadoc) to efficiently track, document, and communicate all project-related
activities.

By leveraging our expertise in construction materials
testing, inspection, and compliance verification, Twining is committed to ensuring the success of the City of Santa Clarita’s overlay program.

Twining | City of Santa Clarita 18
Project Schedule and Timeline

1. Availability and Work Periods
The Twining consultant team will be available throughout the project duration, commencing immediately upon contract execution. Our work schedule will align with the City’s construction timeline and will be closely coordinated with the project manager to ensure smooth execution.

We recognize that some work may be performed during night shifts. Twining’s team is fully prepared to accommodate such scheduling needs. We will work closely with the City’s project manager to understand night shift start and finish times, allowing us to allocate additional resources as necessary to meet project demands.

Twining’s project manager and field supervisor will be available throughout the project to coordinate with the City’s project manager, ensuring that workforce resources are allocated efficiently based on daily tasks. With a team of over 150 inspectors on standby, Twining has the capacity to meet any workload demands during construction, ensuring uninterrupted progress and quality assurance.

2. Key Milestones and Completion Dates
The following schedule outlines key milestones aligned with the City's timeline:

Task/Subtask Start Date End Date Milestone/Deliverables Contract Execution March 2025 March 2025 Contract finalized and signed
Pre-Construction Meeting March 2025 March 2025 Kick-off meeting with City and stakeholders
Material Sampling &
Testing Setup
March 2025 April 2025 Testing protocols and
schedule confirmed
Field Testing and Inspection April 2025 November 2025 Ongoing field inspections, daily reports
Weekly Progress Meetings April 2025 November 2025 Updates to City officials and contractors
Mid-Project Quality
Assurance Review
June 2025 June 2025 Compilation of material
compliance data
Final Testing and
Certification
November 2025 December 2025 Final project materials
certification
Project Completion and
Closeout
December 2025 December 2025 Submission of final
reports and compliance
documentation

4. SCHEDULE
Twining | City of Santa Clarita 19

4. Schedule

3. Proposed Meeting Schedule
To ensure effective coordination and progress tracking, Twining will participate in the following key meetings:
• Kick-off Meeting (March 2025): Introduction of the team, discussion of project objectives, and confirmation of schedules.
• Pre-Construction Meeting (April 2025): Coordination of project details, discussion of construction plans, and clarification of testing requirements and responsibilities among the City, contractor, QC, QA, utility companies, and any other stakeholders.
• Weekly Status Meetings (April - November 2025): Ongoing progress reviews, issue resolution, and stakeholder updates.
• Mid-Project Review (June 2025): Verification of testing frequency and updates to compliance documentation. • Project Closeout Meeting (December 2025): Final review of materials, test results, and compliance summary.

4. Contingency Planning
The project schedule is subject to variables such as weather conditions, contractor availability, and unforeseen delays.

Any necessary adjustments will be communicated promptly, and we will coordinate with the City’s project manager to implement schedule modifications while minimizing disruptions to the project timeline.

Twining | City of Santa Clarita 20
Twining is able to self-perform all work identified in the RFP and does not anticipate the use of subconsultants for this contract.

5. SUB-CONSUL TANTS
Twining | City of Santa Clarita 21
Grounded in Safety, Built on Sustainability

CITY OF SANTA CLARITA

COST PROPOSAL TO PROVIDE
2024‐25 Overlay Slurry Seal Program ‐ Materials Testing and Inspection
PROPOSAL # CIP‐24‐25‐M0157M
March 7, 2025
This proposal is a firm offer for a 120-day period, and the proposed work will be performed at a “not-to-exceed” price.

Twining has reviewed the City’s professional services agreement and finds the agreement acceptable as written.

Mariel Attento Rhorer
Vice President of Client Development
(Authorized to bind the firm)

1. STATEMENT OF OFFER AND

SIGNATURE

Estimated
Number of Hours
800
1320
720
900
400
960
900
400
200
480
400
360
80 Daysd
ARHM
R&R
AreasaC2 ACD2 ACTotal
CT 202Aggregate Gradation1 Per 750 Tons,
Minimum 1 Per Day60406025205
CT 217Sand Equivalent1 Per 750 Tons,
Minimum 1 Per Day60406025245
CT 382Asphalt Content1 Per 750 Tons,
Minimum 1 Per Day60406025185
CorescPercent Compactiond,e1 Per 250 Tons,
Minimum 3 Per Day18012018075555
CT 309Rice Density1 Per Day60406025185
CT 226 or CT 370HMA Moisture Content1 Per Day60406025185 CT 366Stabilometer Valuef1 Per Day60406025185
CT 367gAir Voids Contentf1 Per Day60406025185
City of Santa Clarita
2024-25 Annual Projects
City Project No. M0157
Quality Assurance Testing Program
Inspection, Sampling, and Quality Assurance Management
Position a
Unit CostbOvertime RateDoubleExtended Cost Time Rate
Project Management/Engineering Oversite: Responsibilities include project oversite and engineering support.185------ $ 148,000.00 Public Works Inspection: Responsibilities include providing full-time inspection to the City.132198264 $ 174,240.00
QC Manager/Engineer: Responsibilities include oversight of Quality Assurance operations and review of test results.156------ $ 112,320.00 Laydown Inspector (8 hour day) : Responsibilities include mat inspection and sampling122183244 $ 109,800.00 Slurry Inspector (8 hour day) : Responsibilities include crackfill, mat inspection and sampling122183244 $ 48,800.00
Compaction Inspector (8 hour day): Responsibilities include monitoring compaction and temperatures behind the roller.122183244 $ 117,120.00 Plant Inspector (8 hour day): Resonsibilities include inspection and sampling of aggregates, binders, and hot mix asphalt.122183244 $ 109,800.00 Laydown Inspector (4 hour day) : Responsibilities include mat inspection and sampling.122------ $ 48,800.00 Slurry Inspector (4 hour day) : Responsibilities include crackfill, mat inspection and sampling.122------ $ 24,400.00
Compaction Inspector (4 hour day): Responsibilities include monitoring compaction and temperatures behind the roller.122------ $ 58,560.00 Plant Inspector (4 hour day): Resonsibilities include inspection and sampling of aggregates, binders, and hot mix asphalt.122------ $ 48,800.00 Clerical107------ $ 38,520.00
Coring Technicianc: Responsibilities include the extraction of cores and the filling of holes following extraction.358------ $ 28,640.00 a All inspectors, samplers, testers, and labs must posess all current Caltrans certifications relevant to their Total Cost $ 1,067,800.00 b Hourly cost includes travel of inspector/technician to and from the jobsite as well as all sample transportation c Includes travel, coring, and sample transportation only, testing of cores is listed as a separate item. d Rate for coring technician is based on a per day basis.

City of Santa Clarita
2024-25 Annual Projects
City Project No. M0157
Quality Assurance Testing Program
Materials Testing
Test Method(s)Quality Characteristic
Minimum Sampling and
Testing FrequencyLocation of SamplingUnit CostExtended Cost Slurry At Plantb20242 $ 49,610.00
At Plantb60182 $ 44,590.00
Mat Behind Paverb---242 $ 44,770.00
Compacted Mat---94 $ 52,170.00
Mat Behind Paver---182 $ 33,670.00
Mat Behind Paver---inlcuded $ - c Item includes the cost of testing core specimens in the lab. d Though core samples are used for acceptance testing, monitoring of compaction by use of a nuclear gauge shall be required throughout the paving day. e Compaction shall be determined using the formula 100 x (Bulk Specific Gravity (CT 308)) / (Maximum Theoretical Specific Gravity (CT 309)). f Report the average of 3 tested briquettes from a single sample. g Use CT 309 to determine maximum theoretical specific gravity in place of the CT 367 calculated maximum theoretical specific gravity. h Test must be performed by an AASHTO certified laboratory. i No testing of binder will be required except at the discression of the engineer, sample and store all material until the engineer approves disposal.

Mat Behind Paver---242 $ 44,770.00
Mat Behind Paver---242 $ 44,770.00
a Sample digout material at the regular frequency.Total Cost $ 314,350.00 b Exact tonnage and location of sample to be determined by the materials sampling Random Sampling Plan and coring Random Sampling Plan.

Grounded in Safety, Built on Sustainability

Santa Clarita City CouncilApril 22, 2025

Santa Clarita City Council
April 22, 2025