Several hydrographic and hydrothermal studies have been conducted since 1965 (NUSCo 1983c). 

 These studies were of two types. Some were designed to predict the shape and extent of the plume under 

 1-, 2-, and 3-unit operations. Others were field studies designed to determine the general hydrographic 

 nature of the waters surrounding MNPS or to verify the shape and extent of the thermal plumes (NUSCo 

 1979d). In addition, a tidal circulation model was developed that predicted current patterns and thermal 

 distributions and simulated dispersal and entrainment of Niantic River winter flounder larvae (Hess et al. 

 1975; Saila 1976). 



As a result of these studies, the hydrographic and ecological characteristics of surrounding waters are 

 described. Studies have been intensified and modified to provide the most representative data with respect 

 to the changing concerns and state-of-the-art techniques. The present report provides results of studies 

 conducted during two-unit operations and provides a basis for evaluating any long-term impacts associated 

 with three-unit operations at Millstone Point. The report also satisfies certain license and permit conditions 

 stipulated by the Connecticut Department of Environmental Protection and the Connecticut Power Facility 

 Evaluation Council. 



All ecological and hydrographic studies through 1976 were conducted by consulting laboratories, most 

 notably Battelle - W.E. Clapp laboratories, Woods Hole Oceanographic Institute and Normandeau 

 Associates. In 1977, Northeast Utilities Service Company (NUSCo) began a phased, in-house takeover 

 beginning with the entrainment and impingement programs. Some benthic and lobster program respon- 

 sibilities were added in 1978. As of January 1980, all studies (excluding heavy metals) were being conducted 

 and reported by NL'SCo scientists based at NUEL. Critical scientific review is provided by a four-member. 

 Ecological Advisory Committee (see acknowledgements) that has provided continuing support since 1968. 



Data from the MNPS monitoring programs, the results of which are presented in this summary report, 

 are stored on discs at NUEL and at Environmental Programs Dept. in Rocky Hill, CT. Appendices to 

 this report are also archived at NUEI,. 



In addition to the monitoring programs described in this report, several studies were conducted in 

 earlier years but were later discontinued (i.e., phytoplankton, zooplankton, heavy metals). A brief summary 

 of these studies' results follows; more detailed results can be found on file at NUEL. 



