3-77 



not return on the flood tide: the water which does not return carries 

 away heat. The projjortion of water that is flushed has not been studied 

 for Now Haven Harbor; however, the assumption used in the model, namely 

 that all the heat returns with the flooding tide, maximizes the temp- 

 erature increase in the harbor and is thus conservative. 



A minimum flow condition that can occur during July and August 

 and corresponding average meteorological conditions for these months 

 were used as inputs to the model. Dispersion coefficients were deter- 

 mined by applying the model to predict the salinity distribution meas- 

 ured during July and August of 1963 (Duxbury, 1963); current speeds and 

 directions were from the same source. 



Figure 3-22 shows the full-depth tidal cycle average harbor 

 temperature increase resulting from operation of the New Haven Harbor 

 Generating Station at 100% capacity (heat load of 545 x 10 Kcal/hr) and 

 operation of the UI English Station at 50% capacity (heat load of 170 x 

 10 Kcal/hr) . The English Station is located on the Mill River and 

 during operation discharges cooling water to model segment 5. The 

 figure shows that the inner part of the harbor is subjected to an 

 average temperature rise of about 0.8 F (0.4 C) with outlying areas 

 about 0.5 F (0.3 C) above ambient temperature. 



The mathematical model-predicted temperatures represent the 

 average temperatures throughout the water column for each segment at a 

 steady-state condition. For steady state to occur, the parameters 

 affecting temperature, i.e., meteorology, freshwater flow, diffusion 

 coefficients, and heat loads, must be constant for periods ranging from 

 about two weeks to a month. In actuality, these parameters are con- 

 tinually varying and a steady-state condition does not occur. However, 

 since Ebasco has chosen realistic worst-case conditions as non-varying 

 inputs, and because the flushing of heat into the Sound is underesti- 

 mated, the temperatures determined by the model can be considered to be 

 conservatively high. 



