T.G. Miller, P.C. follows a team approach, encouraging close working relationships with clients to deliver high-quality workmanship regardless of project size and budget. Our licensed staff includes four Professional Engineers, three Professional Land Surveyors and one LEED Accredited Professional.
All of our professionals reside locally and have a keen awareness of local concerns and government practices. We recognize the need for accessible civil engineering and land surveying services and are able to address client concerns in a timely manner.
We are a local business compromised of local people committed to providing quality service to our community.
T.G. Miller, P.C. follows a team approach, encouraging close working relationships with clients to deliver high-quality workmanship regardless of project size and budget. Our licensed staff includes five Professional Engineers, two Professional Land Surveyors and one LEED Accredited Professional.
All of our professionals reside locally and have a keen awareness of local concerns and government practices. We recognize the need for accessible civil engineering and land surveying services and are able to address client concerns in a timely manner.
We are a local business and local people committed to providing quality service to our community.
Team TGM
Click staff name for contact information and a little personal info.
Owen B. Barden, P.E.
Rachael L. Barnhart
Justin S. Blomquist
Jacqueline L. Dresser, L.S.
Lee Dresser, L.S.

Vice President/Principal Surveyor
ld@tgmillerpc.com
607-272-6477 x 227
Marcus Haider
Construction Administrator
MWH@tgmillerpc.com
607-272-6477 x225
As a Construction Administrator, Marcus is responsible for assisting in the development of plans and specifications for projects through constructability reviews and cost estimates. Marcus also serves as a conduit for communication between engineers and contractors by reviewing submittals, answering RFI’s, performing scheduled SWPPP inspections, and conducting field observations during the construction phases of projects. Marcus has been employed by the firm since May of 2022, and comes in everyday eager to learn under the guidance of senior team members.
Little Known Fact: Marcus is an avid pool player and plays competitively.
Donald (Dondi) M. Harner, P.E., LEED® A.P., C.P.E.S.C.

Vice President/Principal Engineer
dmh@tgmillerpc.com
607-272-6477 x 233
David Herrick, P.E.
President and CEO/Principal Engineer
Patrick King, E.I.T, CPESC I.T.
Patrick King joined the firm in June 2021 as a Civil Engineer. Patrick is from Newfield, New York where he graduated high school in 2017. During his senior year of high school, he participated in the New Visions Life Sciences program at Cornell where he did research and interned with Tompkins County Soil and Water Conservation District (SWCD). This experience led him to major in Environmental Resources Engineering with a focus on Water Resources at SUNY ESF. During his college breaks, Patrick worked as a Conservation Technician at SWCD and on the side for his father’s concrete construction company.
Patrick completed his Bachelor of Science Environmental Resources Engineering from SUNY ESF in 2021. Patrick serves as a member on the Tompkins County Water Resources Council, and is an FAA certified drone pilot. In his spare time, he enjoys trail running, fishing, and hiking in the Adirondacks.
Little Known Fact: Patrick has completed five marathons, including one 40-mile ultramarathon.
Michael Lambert
Surveyor Technician and Licensed Drone Operator
msl@tgmillerpc.com
607-272-6477 x 232
Michael Lambert is currently a Surveyor’s Apprentice, who assists in deed research, file organization, and more since joining the firm in 2024. Michael was born and grew up in the state of Maine where he spent most of his life prior to moving to Ithaca, NY. After completing a two-year degree in Construction and Environmental Technology, he developed a passion for land surveying while completing a micro-credential in Surveying at Tompkins Cortland Community College. Especially drawn to the advancement of survey work using drone technology, he attained his Part 107 Commercial Drone Pilot license.
Before joining TGM Michael owned and operated a successful carpentry business in Maine and Upstate NY, making a living as a skilled woodworker and craftsman. His favorite project to date has been building his own home in Freeville and developing his property alongside his wife during his free time.
Little Known Fact: Mike shares the exact birth date as Tom Brady and is very proud to be a New England Patriots fan in Upstate NY.
Donovan (Donnie) Mason
Surveyor's Apprentice
dam@tgmillerpc.com
607-272-6477 x 224
Donovan Mason joined the firm in 2025 as a Surveyor's Apprentice, where he plays a key role in field operations and office preparation. His responsibilities include deed and boundary research, file and records organization, and assisting survey crews with drafting and equipment readiness. He is eager to grow in the profession by gaining hands-on experience and expanding his knowledge of land surveying practices and the surrounding region. Prior to beginning his surveying career, Donovan served 11 years in the United States Marine Corps and U.S. Army, where he developed a strong foundation in discipline, teamwork, and situational awareness, qualities that now support his transition into technical fieldwork and data collection. When not working, Donovan enjoys spending time outdoors fishing, kayaking, scuba diving, and camping.
Little Known Fact: Donovan lived in Okinawa, Japan for three years and once swam with humpback whales off the surrounding island chains.
David O'shea, P.E.

Project Manager
dlo@tgmillerpc.com
607-272-6477 x 234
David received a Bachelor of Technology in Civil and Environmental Technology from SUNY Canton in 2015. David has over a decade of municipal engineering experience, ranging from utility projects to facility improvement and renovation projects. David's experience comes from past employment with one of Tompkins County's largest municipalities.
Little Known Fact: David can usually be found performing home renovations, or helping friends preform theirs, on the weekends.
Justin Pettit
Civil Engineer
jwp@tgmillerpc.com
607-272-6477 x 238
Justin Pettit joined the firm in June 2025 as a Civil Engineer. Justin is from Moravia, New York where he graduated high school in 2021. During high school, he worked for his father's construction company building residential buildings from the ground up, which sparked his interest in Civil Engineering. Justin completed his Bachelor in Science in Civil Engineering at Syracuse University in 2025. In his spare time, he enjoys working out, fishing, and spending time outdoors.
Little Known Fact: Justin has competed in powerlifting competitions.
Justin Pettit
Business Operations Manager
kap@tgmillerpc.com
607-272-6477 x 221
Kristi graduated from Tompkins Cortland Community College with an A.S. in Accounting while working full time at Claritas, formerly known as National Planning Data Corporation. She worked her way through the ranks of the Accounting Department before taking a break to raise her son. She has worked with the Town of Dix in the capacity of Administrator and as Court Clerk. For six and a half years, she also worked for the Halpin Firm handling Commercial Real Estate transactions. Her experience with municipal and legal work has given her experience that has assisted in her transition to T.G. Miller.
Little Known Fact: Kristi volunteers in her community by being a part of the Schuyler County Learn Not to Burn Program and part of the Montour Falls Fire Department. Both causes being near and dear to her heart, as both her Son and Husband are firefighters.
Gail Sgrecci
Administrative Assistant
gss@tgmillerpc.com
607-272-6477 x 220
Gail’s voice is likely the first one you’ll hear at T.G. Miller, P.C. As an Administrative Assistant, Gail provides secretarial support and assistance with administrative tasks primarily for the Surveying Division Staff. She is responsible for answering the phone and daily record-keeping – from initial project intake, invoicing, and filing – digitally and physical survey records.
She graduated from Elmira College with a B.A. in History/Anthropology. She spent a year in Washington, D.C. where she worked at the National Geographic Society in the Administrative Services Department along with the Research Grant Department. She returned to New York and was hired by Thomas G. Miller, P.C./L.S. himself. She stayed for ten years as a secretary, leaving to start a career as a dairy farmer and raise a family. After 25+ years of owning/working a successful organic dairy farm and raising her four children, she and her husband transitioned to raising organic grass-fed angus beef cows. In an effort to keep busy once the dairy cows were gone, Gail has decided to start her next chapter at TGM.
Little Known Fact: Gail can ride a unicycle.
Mitchell Westfield, E.I.T.

Civil Engineer
mpw@tgmillerpc.com
607-272-6477 x 229
Mitchell Westfield joined the firm in 2023 as a Civil Engineer. Mitchell is from northern Kentucky and moved to Ithaca in 2023. Mitchell completed his Bachelors of Science in Civil and Environmental Engineering in 2021 and his Masters of Engineering in Civil and Environmental Engineering with a focus in Water Resources in 2022, both from the University of Louisville. Mitchell previously worked for USACE Louisville District, and has previous experience in civil site design, hydrology and hydrologic design, water resources, and risk management.
Little Known Fact: Mitchell enjoys competing in gaming competitions in his spare time.
Project Manager


