3-88 



this time the 1 F AT isotherm bounded 30.5% of the cross-sectional area 

 of Transect F (Figure 3-26) . 



At maximum ebb, the ])lant's thermal plume had tlic greatest 

 horizontal extent (Figure 3-27) . Temperature rises of 4 F occurred 

 above the discharge. Temperature increases of 1 to 2 F extended beyond 

 Fort Hale Park. The area bounded by the 1 F AT isotherm is equal to 

 12.6% of the surface area of the inner harbor. Cross-sectional data 

 show water with increased temperature of 2 to 3 F extending from surface 

 to bottom in the water column at the transect just south of the dis- 

 charge where the plume enters the main channel (Transect G, Figure 3- 

 27) . At this time there was no area in the main channel at Transect G 

 which did not have a temperature rise of at least 1 to 2 F. Further 

 south of the discharge point, the pliome apparently thinned out and 

 possibly formed a surface layer 1 to 2 m thick. 



Generally, the NAI dye and thermal surveys showed that the 

 percentage of the surface area of the inner harbor subjected to a 

 temperature rise of 1 to 4 F was small. In each study, the area bounded 

 by the 4 F AT isotherm was equal to or less than one-tenth of one per- 

 cent of the total inner harbor area. The areas bounded by AT isotherms 

 of 3 F ranged from zero to 0.4% in October and from 0.1% to 0.5% in 

 August. A much larger area was bounded by the 2 F AT isotherm; the 

 percentage affected ranged from less than 0.1% to 3% in October and from 

 0.5% to 5.5% in August. The percentage of surface area bounded by a AT 

 of 1 F ranged between 0.7% and 12.6% in October and between 2.7% and 

 11.2% in August. 



In October, the percentage of the cross-sectional area of 

 Transect F bounded by the 4 F AT isotherm was zero during four of the 

 eight tide phases studied, and it ranged to a maximvun of 2.9% during low 

 slack on October 13. For August, the range was between zero and 3.2%. 

 The 3 F AT isothejrm bounded up to 6.7% and 8.5% of Transect F in October 

 and August, respectively. The area bounded by the 2 F AT isotherm 

 ranged from 1.9% to 22.8% in October and from 10.4% to 20.6% in August. 

 The areal extent of the 1 F AT contour was quite variable in October, 



