Who are we?
ZT Consulting Group is a Southern California based consulting engineering company that provides services to public transportation agencies. Consider us your partner, and as such we are always on call and always available for everything from simple brainstorming sessions to representing you during meetings with stakeholders.


The majority of our staff has served and completed numerous public projects within the State of California over the past decade. We understand the requirements, challenges, and objectives of public projects.



Our Certifications

ZTC staff have qualifications and certifications from various nationally recognized organizations.



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Principal Engineer

Farzad Tasbihgoo, PhD, PE, CQA, CWI, PCI III 

Farzad Tasbihgoo is a registered civil engineer with about two decades of work experience in structure construction and engineering design. He has a strong engineering design background with extensive experience in source inspection and quality assurance services. 

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Quality Assurance Inspector

Andrew Soria, PCI III, ACI I, CWI

Andrew is an experienced precast concrete inspector with about 13 years of experience in mix design, concrete placing, sampling, testing, inspection, and quality control of precast concrete panels. He is Precast Concrete Institute Certified Quality Control Level III (PCI III), the highest precast inspection certification an inspector can achieve. 

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Assistant Quality Engineer

Derick Hobbs, EIT, ACI I, PCI II

Derick is an experienced Assistant Quality Engineer (AQE) with over 3 years of experience. He has a degree in Civil Engineering and holds an E.I.T Certification with the State of California. Derick has developed knowledge of Caltrans Standard Specifications while working as an AQE.

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Quality Assurance Technician

Richard Corona

Richard is an experienced source inspector with more than 20 years of experience working for Caltrans Material Testing Engineering Services (METS) in the Office of Structural Materials (OSM), Los Angeles branch. Richard is among few QA inspectors that started working for Caltrans METS/OSM.

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Administration/Business Development-

Ileen Robles 

Ileen is an experienced office administrator with extensive knowledge in business development. She coordinates all office activities and operations between ZTC offices and staff travels. She prepares all of ZTC RFPs and participate in networking events.

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Quality Assurance Inspector

Paul Mortsolf, PCI II, ACI I

Paul is an experienced QA precast inspector with about 12 years of precast fabrication production and inspection. He was QCM at major precast fabricator for about 10 years and has been working as QA inspector for the past 2 years. He has extensive knowledge of Caltrans Specification for Concrete and precast fabrication.



ZT Consulting Group, Inc. (ZTC) is a consulting engineering company that specializes in Quality Assurance & Source Inspection (QA, QV, IQA, QMP, SIQMP, QAP and QAM), Forensic Engineering, and Structural Health Monitoring (SHM). At ZTC we are a group of professional registered engineers and technicians with decades of experience in design, construction, and fabrication support services.

Source Inspection
Structural Health Monitoring


Projects Completed




San Bernardino County Transportation Authority (SBCTA)

Orange County Transportation Authority (OCTA)

Alameda Corridor East

Construction Authority

City of Los Angeles


Madera County

City of Monterey

Los Angeles County Metropolitan Transportation Authority (LACMTA)

City of Hanford

Riverside County Transportation Department


Port Authority of New York & New Jersey



Please send your email requests to info@ztcgrp.com.


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Office Locations

Los Angeles Office     

1041 E Green Street

Suite 204

Pasadena, CA 91106

Tel  | (626) 714 - 7181


San Bernardino Office   

9087 Arrow Route

Suite 260

Rancho Cucamonga, CA 91730


Tel  | (909) 351-2078



Fax | (818) 369 - 6867