Evaluating Thermal Impacts to an Estuarine Balanced Indigenous Community for 316a Demonstrations

As part of the NPDES permit renewal process, the Taunton Municipal Lighting Plant (TMLP) will conduct a 316(a) Demonstration Study to evaluatge the effect of their existing thermal discharge variance. AECOM has assisted TMLP with designing and implementing a multidisciplined approach for assessing the impacst to the Balanced Indigenous Community (BIC) and defining the zone of fish passeage during thermal discharges. Oceanographic and biological data was collected in the facilities discharge creek and  the subsequent recieving waters of the Taunton River mainstem in support of Hydrological CORMIX modeling and biological community assessments comparitve to a nearby reference creek with similar physical attributes. Adult and juvenile fisheries surveys were used to determine migratory and resident species present and evaluate potential behavioral responses as a result of thermal plume mixing at the confluence of the discharge creek and Taunton River which included quantifying the zone of fish passage under various tidal scenarios. Additional studies ito determine direct thrermal impacts in the discharge canal and mainstem mixing zone with respect to the reference creek included; ichthyoplankton density and diversity surveys; infaunal and epifaunal settlement and recruitment assessments; sediment characterization, intertidal and subtidal vegetation surveys, and physiochemical water quality monitoring. Data from the thermally impacted areas were compared to baseline information and reference creek results to assess the impact to the BIC.