Organization

About Ron Adderley

Ron Adderley became Director of Support Services in June 2025, after serving as Acting Director since September 2023 and Deputy Director since October 2021. Ron was previously the Fleet Management Division Director, where he managed the purchase and maintenance of approximately 3,000 vehicles and equipment; fuel delivery of over 5,000,000 gallons per year at 11 fuel sites; and surplus vehicles, equipment, and other items totaling more than $1,000,000 per year.

Ron previously served as the Field Operations Manager and Capital Improvement Program Manager for the city of Centennial, Colorado, and as the Field Services Manager for the city of Sandy Springs while with CH2M HILL. Prior to that, he was the Construction and Maintenance Division Manager for the city of Roswell Transportation Department and was a Construction Project Manager with the Georgia Department of Transportation. He also served as an original member and supervisor of GDOT’s H.E.R.O. program in metro Atlanta.

Ron and his wife, Jane’t, have one daughter.

David Mogge
Deputy Director
770.822.7082
David.Mogge@GwinnettCounty.com

About David Mogge

David Mogge became the Deputy Director in February 2021. David was previously the Facility Construction Division Director. In this role, David managed a team responsible for design and construction of new general government facilities such as fire stations, police stations, and libraries; capital maintenance projects such as roof replacements, HVAC replacements and upgrades, and plumbing upgrades; and major facility renovations. Dave began his career with Gwinnett County in 2013 as an Engineering Coordinator in the Support Services Department. He also serves on the Gwinnett County Environmental Sustainability Committee.

Prior to joining Gwinnett County, Dave served as a project engineer with the U.S. Army Corps of Engineers. He started his career as a Civil Engineering Officer in the United States Air Force and remains active in the United States Air Force Reserve as a commissioned officer.

Dave is a professional engineer and a certified energy manager, and he earned both Master of Engineering and Bachelor of Science in Civil Engineering degrees from the University of Florida.

Dave and his wife, Adrienne, have two sons.

Jerry Dennis
Deputy Director
770.822.7015
Jerry.Dennis@GwinnettCounty.com

About Jerry Dennis

Jerry was named Deputy Director in July 2025. He was named Facility Construction Division Director in August 2024. He joined the County in May 2023 as a Program Manager with the Facility Construction Division.

Prior to joining Gwinnett County, Jerry worked for over 23 years with various architecture and engineering firms and is a licensed Architect specializing in the planning, programming, design, and delivery of a variety of public building projects to include law enforcement facilities, administration buildings, courthouses, public safety facilities, and other specialized and complex government and municipal projects.

Jerry earned a Bachelor of Architecture degree from Auburn University, holds a certification with the National Council of Architectural Registration Boards, and holds a Building Design + Construction professional accreditation with the United States Green Building Council’s Leadership in Energy and Environmental Design Program.

Outside of work, Jerry enjoys spending time with his wife, traveling, and fishing.

Morry Alls
Facility Construction Division Director
770.822.7117
Morry.Alls@GwinnettCounty.com

About Morry Alls

Morry Alls became the Facility Construction Division Director in November 2025. He joined Gwinnett County in 2022 as a Program Manager within the Facility Construction Division.

Before joining Gwinnett County, Morry spent more than 20 years in both the public and private sectors, working with various firms and specializing in facility and construction management, as well as contract administration. He holds a Bachelor of Arts in Architecture from Tuskegee University and has directed facilities at multiple HBCUs, including Clark Atlanta University, Howard University, and his alma mater, Tuskegee University.

Outside of work, Morry enjoys watching sports, cooking, and spending time with his family. He is proud to continue growing his career and deepening his roots within Gwinnett County, where he is also a resident of Sugar Hill and remains actively involved in his community.

Brinston Williams
Fleet Management Division Director
678.442.3303
Brinston.Williams@GwinnettCounty.com

About Brinston Williams

Brinston Williams joined Gwinnett County in May 2024 after serving as Fleet Manager for Gwinnett County Public Schools (GCPS) where he managed a fleet of over 2600 vehicles. GCPS operates the largest school district owned and operated school bus fleet in the United States. In addition to many other projects and responsibilities, Brinston managed the screening, interviewing, and onboarding of all 94 Fleet staffers including mechanics, parts clerks, and administrators.

Prior to joining Gwinnett County and GCPS, Brinston worked for over 20 years for Original Equipment Manufacturers such as Kubota Tractor, Doosan Infracore, and Sandvik Mining and Construction. During his time there, he was responsible for product support management, warranty analytics/reimbursement, and various sales support roles. He’s held responsibilities in finance, sales, and technical support for multiple product lines. He earned his Bachelor of Science degree from California Polytechnic State University in Agriculture Engineering Technology and a Master of Business Administration from the University of Phoenix.

Outside of work, Brinston enjoys traveling with his wife of 24 years and off-road motorcycle riding. They have a son and daughter both attending SEC universities.

Zac Churney
Operations and Maintenance Division Director
770.822.7119
Zachary.Churney@GwinnettCounty.com

About Zac Churney

Zac Churney became the Operations and Maintenance Division Director in February 2022. Zac began his career with Gwinnett in 2018 as an Engineer IV, where he managed a team responsible for the daily operations of the mechanical, electrical, low voltage, and plumbing systems at Gwinnett’s libraries, courthouses, OneStop locations, and other County facilities. Prior to joining Gwinnett, Zac worked as a project and sales engineer with a multifamily HVAC contractor.

Zac earned a Bachelor of Science in Mechanical Engineering from the Georgia Institute of Technology. While at Georgia Tech, he was part of a team that developed a stroller capable of going up stairs. The team was a finalist at the 2014 InVenture prize. Zac is also a member of the American Society of Mechanical Engineers.

Outside of work, Zac enjoys watching sports and golfing.

Clyde Shackleford
Real Estate and Records Management Division Director
770.822.7033
Clyde.Shackleford@GwinnettCounty.com

About Clyde Shackleford

Clyde Shackleford became the Real Estate and Records Management Division Director in October 2020. In this role, Clyde provides management functions related to County owned real estate, records retention and disposal, County mail services, and food service contracts.

Clyde began his career with Gwinnett County in 2012 as a Real Estate Specialist in the Support Services Department. Since then, he served with the Planning and Development Department as a Planner and as the Real Estate Section Manager in Support Services. Prior to joining Gwinnett County, Clyde held positions in land surveying, geographic information system applications, and as a real estate associate broker.

Clyde earned a Bachelor of Arts in Political Science from Virginia Tech. He is also a licensed Real Estate Broker and Real Estate Appraiser and holds professional designations as a Senior Right-of-Way Agent (SR/WA) and Certified Commercial Investment Member (CCIM).

Outside of work, Clyde and his wife enjoy traveling and judging professional barbecue competitions.