PERICLES M. MANTHOS, P.E.

Member Manager, Civil Engineer

Founder of Manthos Engineering,
Peri brings over 30 years of versatile engineering design and management experience to our team. As a former State Highways Administrator, he was responsible for the management of the State Highways Program totaling over $200 million annually. He has also served in key roles on highway, transit, land development and residential projects.

As District Engineer for the State of Hawaii Department of Transportation Highways Division, Mr. Manthos was part of the Civil Defense Team, located in the basement of the City Office Tower. His first involvement with the State was with the Hurricane Iniki infrastructure restoration efforts. He has taken the FEMA Rapid Assessment Workshop and State Public Assistance Program Managers Workshop held at the Emergency Management Institute in Maryland.

MARTIN OKABE, P.E
Project Manager

Manthos Engineering, LLC

Mr. Okabe brings over 40 years of professional engineering experience, including 9 years at the Dept. of Transportation, Highways Division. At HDOT he served as the Construction and Maintenance Engineer for the state of Hawaii. He also served as the Oahu District Engineer (DE) in charge of maintenance, operations, and construction on Oahu highways.

During Mr. Okabe’s time as DE, he spearheaded a public-private committee in conjunction with DTS to review comments in preparation for the planning and design of an Akamai Highways Information (AHI) system. Prior to Mr. Okabe’s public sector experience at HDOT, he served as Vice President of Project Management/Chief Engineer at two consulting engineering firms where he was involved with both planning and design of major projects.

JIANREN LEI, P.E.
Project Manager

Manthos Engineering, LLC

Mr. Lei has over 27 years of experience including a strong CADD background in the preparation and design of reports and construction plans. His experience spans a vast variety of civil engineering and construction projects, including:
• Solid waste design
• Tunnel construction
• Geotechnical investigation
• Superfund remediation
• Airport facility inventory and GIS
• Airfield pavement management
• ADA compliance issues
• Landfill design and construction

For his work on the West Hawaii Landfill, Mr. Lei received the Dick Harding Technical Excellence Award.

In addition to his design experience, Mr. Lei has several years of experience in construction management, project management and field inspection. Mr. Lei has provided project administration and construction inspection in accordance with Hawaii DOT and Federal Highway Administration (FHWA) procedures on the Ft. Weaver Road Widening Project. He also served as Resident Engineer on the Kalaheo Microtunneling project, which involved numerous value-engineered changes to an already complex utilities project and resulted in extensive traffic control plan modifications. He was also the Project Manager for the DLNR American with Disability Act Monitoring and Advisory Services Project.

CHRISTOPHER FIRBY, P.E.
Project Engineer/Project Manager

Manthos Engineering, LLC

Prior to joining Manthos Engineering in Hawaii, Mr. Firby worked as a construction inspector and as Chief Inspector for Connecticut Department of Transportation for 14 years. All projects included roadway construction ranging from full-depth reconstruction to roadway rehabilitation, bridges, and bituminous concrete overlays. The highlight of his career thus far was the completion of the Thread City Crossing Bridge, which finished one year ahead of a three-year schedule due to a collaborative drainage revision.

As ME’s Project Manager, Mr. Firby has overseen multiple construction projects in the past year: Nimitz Highway and Ala Moana Boulevard Resurfacing and Highway Lighting Replacement, Kalaheo Avenue Shoulder Improvements, and completing the close-out phase of the Ft. Weaver Road Widening Project. Previously, he provided engineering services on the Kalaheo Avenue Reconstructed Sewer Project, which included shaft construction, pile driving, microtunneling and jet grouting.

TANYA BAYADOS CM
Construction Management

Manthos Engineering, LLC

Ms. Badayos has provided engineering services to HDOT-HWY on the Fort Weaver Road Widening Project. More recently, she has been involved in three DOT projects for the Honoapiilani Highway on Maui. She assisted with project close (including review of final change orders) for the Olowlau to Puamana Resurfacing Project and provided inspection services for the full duration of both the Ukumehame Tsunami Damage Project and the Lauiniupoko Shoreline Improvements Project.

Ms. Badayos is currently providing inspection services and engineering support for HDOT’s Interstate H-1 Airport Viaduct Repair Project.

ALLEN FIDDLER
Construction Inspector

Manthos Engineering, LLC

Mr. Fiddler brings with him a background of solid knowledge. His previous work has included being a Geotechnician in California, where he performed geoprobe operations, groundwater sampling, soil sampling, vapor probe sampling, health and safety monitoring, and PID/MGM calibration.

LISA MATHIEU
Construction Inspector

Manthos Engineering, LLC

Mrs. Mathieu has specialized concrete experience. Her skills include creating/implementing concrete mix designs; testing concrete for workability, strength, and air entrainment; recognizing and adjusting inconsistencies in concrete mixes; observing placement of concrete and adjusting mix to ensure workability; and testing aggregates and concrete mixes for compliance with state and federal specifications.

KILEY NAKAMURA
Project Inspector

Manthos Engineering, LLC

Ms. Nakamura's experience includes analyzing traffic flow and developement of traffic plans for better vehicle movement along with driver and pedestrian safety measures.

PAUL LYNCH
Project Inspector

Manthos Engineering, LLC

Mr. Lynch brings with him decades of quality control management and inspection experience. Additionally, Mr. Lynch is a stonemason.

TYLER EDRADA
Project Inspector

Manthos Engineering, LLC

Mr. Edrada brings with him decades of quality control management and inspection experience.

DYLAN DANE
Project Inspector

Manthos Engineering, LLC

Mr. Dane brings with him decades of quality control management and inspection experience. Specializing in utilities management, Mr. Nyuha is currently serving as the Lead Construction Inspector on HDOT’s Interstate H-1 Airport Viaduct Repair Project.

NICK NISHIURA
Project Inspector

Manthos Engineering, LLC

Mr. Nishiura comes to us from the HDOT's Waste Water Management project which also included landscape planning.

Manthos Engineering brings the necessary expertise to the many facets of a project

Project Management

Construction Management

Traffic Studies, Engineering and Management

Erosion Study and Control

Highway and Freeway Rehabilitation

Project Design

Environmental Impact Studies

Whether the scale of your project is large or small, we put your job on back the critical path.

Manthos Engineering, LLC. does not distribute your information to third parties without your consent. We understand that visitors to our website may have tracking cookies in their browsers that may collect general information about our web site. We are not responsible for any information collected or distributed to other parties via these cookies. Visitors should be aware that they have the responsibility to monitor all of the cookies installed on their devices and software and that they should perform periodic maintenance on how their browsers handle the behavior of those cookies,

3rd parties and others should be aware that they do not have permission to use any of the contents of any correspondence or messages or any other communication between Manthos Engineering, LLC and their clients and partners.

While we strive to keep all sensitive information secure, Federal, State and City and County Governments as well as Law Enforcement Agencies require companies that do business with them, such as Manthos Engineering, to keep records of email communications, agreements, plans and certain other documents and information for a reasonable amount of time. Manthos Engineering will not share that information unless compelled to do so by law. In the case of extreme emergency that may involve immediate and catastrophic loss of life or property, Manthos Engineeing reserves the right to disseminate non-personal as well as personal information as circumstances deem necessary.

While we try to be as comprehensive and up to date as possible, new technology and new laws can outpace or otherwise affect the ability of businesses to comply with such changes.

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Over the years, Manthos Engineering has gained specialized knowledge in having handled projects that have required multiple disciplines that draw on proven, time tested techniques and materials and has also incorporated new or emerging methods and materials that are proving to be a better way to build and manage the projects that not only improve the lives of people and the beauty of communities but also watches out for environmental concerns in these days of shrinking and disappearing ecosystems.

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