Duffield Associates joins new comprehensive services firm

Duffield Associates LLC has combined with two other engineering and geoscience consulting firms to form a robust national organization offering comprehensive environmental, energy, water and civil infrastructure capabilities.

The combination includes Hull & Associates LLC, headquartered in Columbus, Ohio, and HSW Consulting LLC, headquartered in Tampa, Fla. The combination includes over 275 staff in 20 offices across eight states.

The former leaders of Duffield, Hull and HSW will continue to actively participate as senior leaders within the organization. Gerry Salontai, CEO of the combined firm, said, “Each of these companies has outstanding leadership in place that will allow continued success individually while building a combined leadership team moving forward. Hull, HSW and Duffield provide a complementary set of capabilities that will expand service offerings to our growing client base within the combined companies.”

The entire Duffield team, offices and service offerings will remain an integral part of the combined firm and be bolstered by additional depth and expertise from the new partners. Duffield President Guy Marcozzi, executive vice president of the combined firm, said, “We’re excited to take this deliberate, strategic next step for Duffield Associates, because it enhances our technical breadth and depth to serve our clients, enables us to pivot more effectively toward today’s environmental and infrastructure needs, and provides exciting new opportunities for our professional team.” 

With offices in Delaware, Pennsylvania, Maryland, New Jersey, Ohio, New York, Florida and Texas, the combined firm has a broad geographic reach and builds on an already comprehensive capability set in environmental site assessment and remediation, energy, water resources and treatment, site civil infrastructure, and climate change resiliency, along with marine, coastal and geotechnical engineering. Client markets include the industrial, real estate, energy, transportation and government sectors.

“We look forward to the enhanced value and synergy that this new partnership will bring to our clients and the new opportunities this collaboration will bring to our exceptional team, whose dedication and commitment have enabled Duffield to thrive and grow,” said Deirdre Smith, Duffield chief operating officer.


The combined firm will continue to grow organically by attracting top talent and providing superior service to clients, and inorganically by adding like-cultured firms that expand geographic reach, complement service offerings, and strengthen diversity and experience among the team of professionals. Duffield is growing and looking to hire talented and motivated professionals who share its passion and values.