GZA was contracted by a long-time client, Algonquin Power Windsor Locks (APWL) to secure expedited permitting for the proposed 15-MW combustion turbine at its existing cogeneration facility in Connecticut. The project received a capital grant of $6.5 million from the Connecticut Department of Public Utility Control (DPUC) contingent upon the turbine being operational within 15 months. As an air permit is required prior to construction, allowing for construction, the permitting needed to be completed within 7 months, which is approximately half of the typical permitting time for a similar project. In addition to the time constraints, the project posed several other challenges. Due to space limitations, the emission control systems had to be custom made and they could only reduce NOx emission to 5.0 ppm. CTDEEP policy limits NOx emissions from similar units to 2.5 ppm. The system data needed for permitting was not available as the system design was not complete. The required pre-permitting activities, such as Connecticut Siting Council (CSC) approval, Natural Diversity Data Base (NDDB) review, were not completed.


GZA negotiated a permitting strategy with CTDEEP to address the above issues. To reduce project time, GZA used environmental data from past GZA projects at the facility for the pre-permitting requirements including an NDDB review and, absent timely system data from the manufacturer, GZA developed (based on GZA’s knowledge of turbine systems) the required data for various CSC-specified analyses including ambient impact analysis, which satisfied the CSC. GZA performed a rigorous BACT analysis to justify the higher NOx emission limit. GZA ensured that the application addressed all CTDEEP concerns and was in regular communication with CTDEEP during permitting to minimize review time.


The permitting was completed within the 7-month deadline which allowed APWL to meet DPUC’s 15-month deadline for turbine start-up and receive the $6.5 million grant.