66
E. NAYLOR
33-46°C in various Pennsylvanian rivers, and Cairns (1956) records
exceptional heating to 60°C in Mahoning River at Youngstown, Ohio.
The importance of continuous measurement in determining these
maxima in heated areas is emphasized by Gameson, Gibbs and Barrett
( 1959) who demonstrated considerable diurnal fluctuations in temperature up to 54 miles downstream owing to fluctuations in output at apower
station. For marine localities such figures as are available indicate
temperatures of up to about 40°C for water in the actual discharge
ducts at power stations. Thus Fox and Corcoran (1957) record summer
values of about 3641°C in discharge tunnels of installations in Southern
California and Naylor (1965) records temperatures taken at a power
station ranging from about 23°C in winter to about 37OC in summer in a
locality where mean sea temperatures range from about 7-17°C. Heat
is, of course, dissipated very rapidly from such discharges, the average
rate of heat loss from water being 9.7 Btu/ft2/h/"C excess temperature
(Gameson et al., 1959), so that temperatures in the vicinity of the latter
outfall were about 10 Centigrade degrees lower than those recorded in
the effluent duct, though they were, of course, still higher than normal
sea temperatures (Naylor, 1965). That author showed that in an almost
completely enclosed system of docks used as a cooling pond by a continuously operating coal-fired generating station all the water in the
docks was at least 5 Centigrade degrees higher than outside sea water.
Temperatures near the outfall in this case were at all times between 7-10
Centigrade degrees above those of outside sea water and often reached
nearly 30°C (Naylor, 1959, 1965). Crisp and Molesworth (1951) also
recorded high temperatures of 25°C or more near an effluent in a marine
harbour where temperatures normally ranged up to about 18"C, and
Wolff (1954) recorded water temperatures of 6°C near factory outfalls
in Copenhagen Harbour at a time when the harbour was normally
icebound. In Southampton Water, too, Pannell et al. (1962) recorded
a temperature rise of nearly 3OC for distances of up to a quarter of a
mile away from heated outfalls, at one of which temperatures averaged
about 8 Centigrade degrees higher than a t the intake (Ansell et al.,
1964). I n more open areas heating effects perhaps fall off more quickly
away from outfalls, as Gilet (1960) found near Marseilles where heated
effluents were quickly mixed with Bay of Marseilles water and heated
areas were localized in fairly shallow surface layers or in isolated parts
of the dock system. I n open areas off Southern California, however,
heating appeared to be more widespread, for temperatures higher than
normal were recorded for distances of up to " a few thousand feet ''
away from the industrial outfalls (Resig, 1960).
In an estuary it has been reported that even during periods of low
E. NAYLOR
33-46°C in various Pennsylvanian rivers, and Cairns (1956) records
exceptional heating to 60°C in Mahoning River at Youngstown, Ohio.
The importance of continuous measurement in determining these
maxima in heated areas is emphasized by Gameson, Gibbs and Barrett
( 1959) who demonstrated considerable diurnal fluctuations in temperature up to 54 miles downstream owing to fluctuations in output at apower
station. For marine localities such figures as are available indicate
temperatures of up to about 40°C for water in the actual discharge
ducts at power stations. Thus Fox and Corcoran (1957) record summer
values of about 3641°C in discharge tunnels of installations in Southern
California and Naylor (1965) records temperatures taken at a power
station ranging from about 23°C in winter to about 37OC in summer in a
locality where mean sea temperatures range from about 7-17°C. Heat
is, of course, dissipated very rapidly from such discharges, the average
rate of heat loss from water being 9.7 Btu/ft2/h/"C excess temperature
(Gameson et al., 1959), so that temperatures in the vicinity of the latter
outfall were about 10 Centigrade degrees lower than those recorded in
the effluent duct, though they were, of course, still higher than normal
sea temperatures (Naylor, 1965). That author showed that in an almost
completely enclosed system of docks used as a cooling pond by a continuously operating coal-fired generating station all the water in the
docks was at least 5 Centigrade degrees higher than outside sea water.
Temperatures near the outfall in this case were at all times between 7-10
Centigrade degrees above those of outside sea water and often reached
nearly 30°C (Naylor, 1959, 1965). Crisp and Molesworth (1951) also
recorded high temperatures of 25°C or more near an effluent in a marine
harbour where temperatures normally ranged up to about 18"C, and
Wolff (1954) recorded water temperatures of 6°C near factory outfalls
in Copenhagen Harbour at a time when the harbour was normally
icebound. In Southampton Water, too, Pannell et al. (1962) recorded
a temperature rise of nearly 3OC for distances of up to a quarter of a
mile away from heated outfalls, at one of which temperatures averaged
about 8 Centigrade degrees higher than a t the intake (Ansell et al.,
1964). I n more open areas heating effects perhaps fall off more quickly
away from outfalls, as Gilet (1960) found near Marseilles where heated
effluents were quickly mixed with Bay of Marseilles water and heated
areas were localized in fairly shallow surface layers or in isolated parts
of the dock system. I n open areas off Southern California, however,
heating appeared to be more widespread, for temperatures higher than
normal were recorded for distances of up to " a few thousand feet ''
away from the industrial outfalls (Resig, 1960).
In an estuary it has been reported that even during periods of low