JAN86 JAN87 



Date 



I'lg. 4. Slalion operating conditions January I9S.S tlirough 

 December 1987. On the top graph, the lower dashed hnc is 

 average (Units 1 and 2) intake temperature; upper dashed line 

 is the design efTluenl temperature; the solid line is tlic actual 

 elTluent temperature (average of measurements made at both 

 quarry cuts). Station cooling water usage (m'/s, "cms") is 

 plotted on the middle graph and station power production 

 (MWe) is plotted on the bottom graph. 



construction and operation events with possible 

 ecological impact implications has been prepared 

 as a reference (Table 1, Fig. 5). Briefly, some of 

 the more important events include construction 

 and removal of cofferdams around the intakes, 

 dredging activities, construction of each of the 

 cuts from the quarry into LIS, initial operation 

 of each unit, and the installation of mitigative 

 devices including the fish barriers at the quarry 

 cuts, and fish return sluiceways at Units 1 and 3 

 intakes. Demonstrable effects were noted in con- 

 junction with several of these events, most notably 

 construction of the second quarry cut which 

 changed near-field thermal plume dispersal pat- 

 terns such that higher water temperatures were 

 experienced by the adjacent rocky shore commu- 

 nity. In addition, removal of the Unit 3 cofferdam 

 changed sediment characteristics and correspond- 

 ing infaunal assemblages in the intake area. Si- 

 multaneous operation of three units for the fu-st 

 time also increased the volume of cooling water 

 discharged and resulted in sediment scouring im- 

 mediately downstream of the quarry cuts. These 

 changes and the corresponding ecological effects 

 arc discussed further in this report. 



A separate report section is included for each 

 continuing monitoring program: rocky intertidal 

 communities, benthic infaunal communities, lob- 

 ster population dynamics, woodborers, finfish as- 

 semblages and winter flounder population dynam- 

 ics. In addition, two special sections are included, 

 one discussing the theory and application of 

 means calculated from a delta distribution and 

 the other containing a summary of the results of 

 hydro thermal studies done in 1987 during three- 

 unit operation. 



Introduction 



