About us

  • DHDC EngineeringConsulting Services

  • DHDC Engineering Consulting Services, Inc. (DHDC) is a DBE, MBE, EDGE, SBE, LEDE engineering consulting firm. DHDC is headquartered in Columbus with offices in Middletown and Cleveland (TP), Ohio.  We are prequalified by ODOT under Geotechnical (engineering, drilling, and laboratory), Subsurface Utility Engineering (SUE) and we are also certified for "Special Inspections" under the Ohio Building Code (OBC)-Chapter 17 from the Board of Building Standards. Our laboratory is certified by the American Materials Reference Laboratory (AMRL) and Cement and Concrete Reference Laboratory (CCRL) and meets all American Standards for Testing and Materials (ASTM) and American Concrete Institute (ACI) specifications. DHDC is a GREEN SPOT participating firm in the City of Columbus.


    DHDC practices AASHTO R18 quality assurance, including maintaining records of all in-house calibrations and external calibrations. DHDC is in good standing for numerous ASTM and AASHTO procedures in concrete, soils, asphalt, and aggregate through AMRL. We are currently active in the AMRL and CCRL proficiency sample programs. DHDC keeps up with all proper safety procedures including eye wash stations, proper storage of chemicals, and proper heat and eye protection requirements.

LOOKING FOR AN ENGINEERING SOLUTION FOR YOUR COMPANY? DHDC can help! Our professional team works to increase productivity and cost effectiveness.

Our Dedicated Team

DHDC's highly qualified team is comprised of 20 licensed engineers, construction managers, environmental experts, and support staff who combine their technical skills, experience, dedication, and enthusiasm to providing the highest quality services through a combined team effort. DHDC's key contacts comprise: M. O. Haque , M.S, P.E , President, Savvas Sophocleous, Vice President, Mike Sminchak, Operations Manager and Gisella Mandriotti, Office Manager.

M. O. Haque


Michael Sminchak

Operations Manager

Gisella Mandriotti

Office Manager

I am delighted to recommend DHDC Engineering Consulting Services as a qualified firm to provide Geotechnical, Subsurface Utilities Engineering (SUE), construction materials testing, and inspection services. DHDC Engineering has successfully provided those services to the City of Columbus for the last few years. DHDC Engineering has attention to detail in mind, and always provides high quality work. DHDC Engineering has played a key factor to the success of many of our projects and we look forward to working with them in the near future.

In 2012 and 2013, DHDC performed soil borings and submitted a Geotechnical Subsurface Investigation Report for a proposed storm sewer casing under CSX RR along Trabue Road; In 2016, DHDC performed soil borings for Thoburn Road Improvements following ODOT Geotechnical Procedures.  Savvas Sophocleous was our main point of contact at DHDC. Savvas' reports for both projects were complete, accurate, and delivered early. He was always quick to respond to questions and requests, and he provided very good service! The fees DHDC charged were reasonable and fair. We recommend DHDC for their high quality geotechnical engineering services,and look forward to working with them again!

DHDC has been providing construction materials testing services along with other various engineering/construction services to the City of Upper Arlington for the past decade. DHDC provides us with quick responses to our needs and at the same time provides us with the lowest prices available. In working for government entities, it is rare to find such excellent customer service at the low bid pricing that DHDC can provide. For these reasons, I expect that DHDC will continue to be our top choice for construction materials testing and other related consulting services for a long time in the future.

Our Clients

At DHDC Engineering Consulting we care about our clients. We have worked hard to establish lasting relationships that go beyond merely making a profit.

If You Need Any Engineering Solution ... We Are Available For You

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