Cook Plant preoperational studies, 1969 / John C. Ayers ... [et al.].

Station locations are indicated in Figure 12.
Surface temperature distribution is shown in Figure 13. Surface water warmer
than 16~C occupied a limited area north of the plant's breakwall. The vast majority
of the plume's surface area was occupied by water of 13~ to 15~, and water of 13~
to 14~ occupied more than half the plume area. The 13~ isotherm is here taken as
the edge of the plume, inferring retention of 0.2~ of plant-added heat. Figures
14 through 22 show the subsurface temperature distribution from a depth of 1 foot
to 9 feet. Table 8 lists the surface and subsurface temperatures for all stations
at a 1-foot interval to each station' s maximum depth. The upwind stations, WP-2 and
3, agree in indicating a common bottom temperature of 12.6~ but disagree in indicating
surface temperatures of 12.8~ and 13.0~. We have elected to honor 12.8~ as the most
probable incoming ambient temperature; note, from Table 8, that Station WP-4 is
isothermal at this temperature throughout 18 feet of depth. We assign 12.9~ to
being within the limits of error of this experiment and do not consider iL to be
contourable as being a part of the plant's thermal plume. We have doubts, unsupported
by evidence, that 13.0~ should be accepted as the edge of the plant's thermal plume,
but accepting it as such gives an ultraconservative large extent to the plume.
Under these conditions the plume could be identified, at nine feet of death,
as extending about 6000 feet northward along the shore and reaching about 3000 feet
off shore. Too many stations drop out as depth increases to allow reasonable
contouring at the greater depths.
Samples of phytoplankton, zooplankton, and benthos were taken at Stations WP-1
in the outfall channel, WP-2 as near the intake channel as possible, and at Station
WP-13 near the outfall channel and in the thermal plume of the plant.
Discussion of Biological Data
Phytoplankton were abundant at Waukegan. Kill-off by passage through the
plant was shown by a drop in numbers from 6,632,000 cells per liter in the intake

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