1-17 



The primary direct discharge from the plant into harbor waters 

 is the cooling-system water to which plant operation adds its waste 

 heat; no other toxic element is contributed by the station. The waste 

 heat is not anticipated to impact harbor biota directly, based on a 

 consideration of known temperature tolerances for 14 selected repre- 

 sentative species of fishes and invertebrates. This conclusion is 

 qualified by maintenance of water temperatures within the imposed 

 discharge temperature limitations of AT 15°F and a 90°F maximum (NAI, 

 1976) . 



The permit conditions related to blockage of "zones of pas- 

 sage" and "contact with the surrounding shoreline" are satisfied by the 

 thermal plume description studies including the 1976 infrared overflight 

 and 1977 dye and thermal surveys. 



The answers to the question as to whether or not there has 

 been interference with spawning and alteration of the "balanced indi- 

 genous population of New Haven Harbor or its tributary waters" has been 

 a basic consideration of the ecological monitoring program. Guidance 

 with regard to these concerns was provided by the US EPA (1977b) . 

 Specifically, EPA (1977b) stated: 



Any significant change in standing crop may 

 indicate an adverse impact resulting from the heated 

 discharge, and any appreciable alteration in the com- 

 position and relative abundance . . . constitutes an 

 imbalance in the community and indicates possible 

 adverse impact. 



Though the New Haven Harbor Station Ecological Monitoring 

 Studies program was designed prior to this specific EPA statement, the 

 program design quite clearly reflects these considerations. The program 

 objectives were to establish baselines of patterns in ecological param- 

 eters so that possible deviations could be identified after the plant 

 commenced operation. Impacts, adverse, non-important or beneficial, 

 were to be sought in changes of composition, relative abundances and 

 spatial and temporal distributions. 



