13-3 



The inner harbor (1600 acres, bounded on the north by the 

 confluence of the Mill and Quinnipiac Rivers, and on the south by a line 

 from Sandy Point to Fort Hale) experiences greater environmental stress 

 due to direct discharges of municipal and industrial wastes than the 

 outer harbor (5500 acres, bounded by inner harbor, and Long Island Sound 

 breakwaters) . Inner harbor waters also characterized by natural high 

 thermal, salinity, and river sediment load fluctuations. 



Impact 



Condenser cooling water for the New Haven Harbor Station is 

 withdrawn from the harbor via a dredged intake channel which extends 

 from the main ship channel approximately 270 m (886 ft) to the eastern 

 shore (Figure 13-1) . Water currents at the western end of the intake 

 channel are deflected less than 20° eastward from their essentially 

 north-south orientation by this withdrawal. An intake incurrent of not 

 more than 25 cm/sec (0.8 fps) rapidly diminishes to less than 10 cm/sec 

 (0.3 fps) a few meters out from the intake structure. 



Heated cooling water is discharged horizontally through a 

 single diffuser port approximately 210 m (700 ft) from shore and 11 m 



(35 ft) below mean low water. Discharge water velocity, up to 300 

 cm/sec (10 fps) , creates maximum currents of no more than 90 cm/sec 



(3 fps) near the easterly edge of the ship channel. Added heat is 

 usually sufficient to cause the discharge plume to rise to the surface. 

 Only occasionally, during late winter and early spring periods of high 

 runoff has a submerged plume been observed. Although under a certain 

 combination of wind and tide it may be possible that the plume might 

 briefly contact the eastern shore, there has been no evidence to date 

 of any such occurrences. 



Aerial infrared radiometry and three-dimensional thermal and 

 dye studies have shown a maximum temperature rise (AT) in surface waters 

 of about 2.8°C (5°F) above ambient. The percentage of the surface area 



