A baseline biological characterization of source water in support of a permit renewal for a cooling water intake structure

OUR CHALLENGE

A client aimed to redevelop a former industrial facility into a sustainable 10–MW data center to house core computing services and information technology equipment. The redevelopment required an updated National Pollutant Discharge Elimination System (NPDES) permit due, in part, to a proposal for withdrawing water from an upstream impoundment through an existing water intake structure to generate electricity and provide cooling water. Integral performed a detailed biological characterization of the source water under the 316(b) federal regulations. 

OUR APPROACH

Using available published literature, including site-specific studies, we summarized fish community composition and distribution data, including species, life stages, and relative abundance in the impoundment. We also summarized the expected spawning and larval periods for all the fish species; described the specific spawning behaviors to identify species and life stages with a higher potential for impingement and entrainment (I&E) by the intake structure; identified and evaluated the primary period of reproduction, larval recruitment, and period of peak abundance; and identified all threatened, endangered, and other protected species that might be susceptible to I&E. 

OUR IMPACT

Our data analysis suggested that the potential for I&E would likely be minimal because none of the fish species present in the impoundment had pelagic embryo–larval life stages susceptible to strongly interacting with the cooling water intake structure. We tabulated, summarized, and presented the biological characterization of the source water based on the specific requirements in the 316(b) regulations and included this information as a core element of the NPDES permit application.