3-66 



July, August and October 1976. During these surveys, Rhodamine WT dye 

 was added to the cooling water inside the generating station. Dye 

 concentrations were converted to temperatures above ambient by assuming 

 a direct relationship between dye dilution and dilution of discharged 

 cooling water (NAI, 1976) . No velocity measurements have been taken in 

 the plume in New Haven Harbor, but by making some qualitative compar- 

 isons between the temperature dilutions measured during the thermal 

 surveys and those predicted by the physical model, it is possible to get 

 an idea of how reasonable it is to expect that plume velocities pre- 

 dicted by the physical model will be present in New Haven Harbor. 



Figure 3-17 shows the results of the surface temperature 

 measurements obtained from the University of Florida physical model. 

 Shown are isotherms of degrees above ambient temperature with the out- 

 flow located at 0.0. Figures 3-18 and 3-19 show the results of the NAI 

 s-urvey conducted during August. During the survey, the plume inter- 

 sected the surface near the easterly edge of the navigation channel; the 

 distance from the end of the discharge pipe to the inner and outer edges 

 of the 4 F (2.2 C) AT isotherm are approximately 61 and 122 m respect- 

 ively (the boil area must be somewhere inside this isotherm) . Figure 3- 

 17 shows the axis of the maximum temperature of the plume in the phys- 

 ical model intersecting the surface 53 m from the end of the discharge 

 pipe. The temperature rise of the discharge water in the boil area in 

 the physical model is also around 4 F (2.2 C) ; however, in this partic- 

 ular model run the temperatxire of the cooling water was increased to 

 10.3 C and the discharge rate lowered to 14 m /sec. Exact comparisons , 

 between the test runs made with the physical model and the measurements 

 made by NAI during 1976 and 1977 vary from test run to test run and 

 between hydrographic and thermal surveys. This is not surprising con- 

 sidering the natural forces in New Haven Harbor that were not taken into 

 account in the model (including wind and wave-induced turbulence) , and 

 the inherent limitations of a physical model. In general, however, one 

 similarity and one difference between the results of the physical model 

 test runs and what has been observed in New Haven Harbor are evident. 

 The difference and similarity can be seen in Figures 3-17, 3-18 and 3-19 



