J.F. Ahern Co. moved up 17 places in Engineering News-Record’s annual environmental firms ranking, placing No. 159 in 2026 compared with No. 176 the previous year. The ranking evaluates companies based on environmental services revenue from the preceding year.
The list covers businesses providing services across environmental construction, engineering, consulting and remediation. Ahern’s position reflects its work in water and wastewater infrastructure, where mechanical construction and process systems support the operation of treatment facilities.
Based in Fond du Lac, Wisconsin, Ahern provides mechanical and fire protection services for commercial and industrial projects across the United States. Its offerings include HVAC, plumbing, controls, sprinkler systems, fire alarms and fabrication.
Wastewater treatment represented 77% of Ahern’s environmental revenue, making it the largest segment of the company’s environmental services business. Water supply and treatment accounted for another 15%, while air quality and clean energy made up the remaining 8%.
Public-sector clients were a major source of this revenue, with state and local governments contributing 90%. The figures highlight Ahern’s concentration in infrastructure-related work serving public agencies and communities.
Mechanical systems, process piping and related construction services are essential components of water and wastewater treatment facilities, supporting the movement and treatment of water and the operation of specialized equipment.
Water and wastewater infrastructure remains an important market for contractors with mechanical construction capabilities. Ahern’s improved ranking provides an indicator of its standing in the environmental services sector, particularly in treatment-related work.
The ranking is based on prior-year revenue and does not, by itself, establish future growth or disclose the value of individual projects. However, the revenue breakdown shows the importance of water infrastructure and public-sector customers to Ahern’s environmental business.
Source: JF Ahern
