Review of EPA's Assessment of 316(b) Technologies for Mount Tom Generating Station

In April, 2014 the Mount Tom Generating Station (MTS), received a draft NPDES permit issued by the U.S. Environmental Protection Agency (EPA) Region 1 that includes conditions to address 316(b) impingement and entrainment. MTS is a 147 MW, once-through cooling, coal-fired facility located along the Connecticut River in Holyoke, MA. Resident, migrating and ESA- listed fish species are present in the area of the intake. 

As part of the permit, EPA conducted a best professional judgment assessment of 316(b) technologies for MTS. Initially, EPA evaluated options for reducing entrainment and impingement and ruled out certain technologies from further evaluation. The costs and environmental benefits of the remaining technologies were then evaluated. Since, other than converting to closed-cycle cooling, none of the available technologies alone would substantially reduce both entrainment and impingement, technologies aimed at reducing impingement were evaluated separately from those considered for reducing entrainment. The costs of technology options were compared to the magnitude of the estimated environmental gains. The benefits of reducing entrainment and impingement were analyzed quantitatively while the overall benefit of saving these organisms was evaluated on a qualitative basis. A review of EPA’s assessment and the resulting technology requirements will be presented.