THE PROBLEM OF OIL POLLUTION O F THE SEA
233
and sump oils are all too likely to be jettisoned down the nearest drain,
together with the results of spills, leakages and overflows. All industries
use petroleum oils in some form or another ; in some branches of the
steel industry, in which plants are almost all sited along sea or lake
shores, large quantities of oil are used in quenching baths.
I n petroleum-producing regions, but not at present in European
waters, off-shore oilfields are a significant source of pollution. Natural
seepages are so well known off Southern California that a coastal
feature is named Coal Oil Point and two are marked on the official
Hydrographic Charts (see Merz, 1959) ; they also commonly occur in
the Gulf of Mexico (Dennis, 1959), the Caribbean and the Persian Gulf.
Oily material reaching beaches from this source usually has a
composition which clearly distinguishes it from oil spilt during commercial activities (Rosen et al., 1959; Ludwig and Rich, 1964). Geologically, oil and natural-gas stocks are associated with salt deposits.
I n many fields, particularly the older ones, large volumes of brine are
produced with the oil. The Lake Barre field was recently discharging
up to 320 000 gal (1 440 000 litres) per day of this (‘ bleedwater ”,
containing 5-35 p.p.m. of oil, into shallow Louisiana coastal waters
(Mackin and Hopkins, 1962). Oily residues were found in bottom
deposits around the bleedwater outlets (about 2 p.p.m. at Lake Barre
and up to 15 p.p.m. elsewhere) but were very local, attenuating rapidly
with distance.
During the process of drilling and tapping the well, carelessness,
ignorance or poor communication can be as serious a cause of pollution
as a t a tanker terminal. Their effects can be minimized by the observation of proper precautions as laid down, for example, by the Institute
of Petroleum (1964). However, towards the end of the drilling operation, a sudden uncontrollable discharge may occur, resulting in a “ wild
well ” (Mackin and Sparks, 1962). This is not infrequent in off-shore
oilfields-Tarzwell (1967) places it at the head of his list of serious oilpollution sources and the Batelle-Northwest Report (1967) notes that
there are about 3 000 active wells off the U.S. coast-but such events
are rarely recorded in the literature. A serious (‘ blow-out ” occurred
off the Texas coast in 1941, but the oil drifted to sea causing no damage
(Bourne, 1968a). The leakage from the Union Oil Company well A-21
off Santa Barbara, California, received much greater publicity and its
effects are still being documented. An initial blow-out at the end of
January 1969 was successfully contained by normal emergency procedures, but oil and gas under pressure were then forced through a
porous layer outcropping to one side of the drilling platform. After
ten days, during which the magnitude of the leakage averaged 21 000
233
and sump oils are all too likely to be jettisoned down the nearest drain,
together with the results of spills, leakages and overflows. All industries
use petroleum oils in some form or another ; in some branches of the
steel industry, in which plants are almost all sited along sea or lake
shores, large quantities of oil are used in quenching baths.
I n petroleum-producing regions, but not at present in European
waters, off-shore oilfields are a significant source of pollution. Natural
seepages are so well known off Southern California that a coastal
feature is named Coal Oil Point and two are marked on the official
Hydrographic Charts (see Merz, 1959) ; they also commonly occur in
the Gulf of Mexico (Dennis, 1959), the Caribbean and the Persian Gulf.
Oily material reaching beaches from this source usually has a
composition which clearly distinguishes it from oil spilt during commercial activities (Rosen et al., 1959; Ludwig and Rich, 1964). Geologically, oil and natural-gas stocks are associated with salt deposits.
I n many fields, particularly the older ones, large volumes of brine are
produced with the oil. The Lake Barre field was recently discharging
up to 320 000 gal (1 440 000 litres) per day of this (‘ bleedwater ”,
containing 5-35 p.p.m. of oil, into shallow Louisiana coastal waters
(Mackin and Hopkins, 1962). Oily residues were found in bottom
deposits around the bleedwater outlets (about 2 p.p.m. at Lake Barre
and up to 15 p.p.m. elsewhere) but were very local, attenuating rapidly
with distance.
During the process of drilling and tapping the well, carelessness,
ignorance or poor communication can be as serious a cause of pollution
as a t a tanker terminal. Their effects can be minimized by the observation of proper precautions as laid down, for example, by the Institute
of Petroleum (1964). However, towards the end of the drilling operation, a sudden uncontrollable discharge may occur, resulting in a “ wild
well ” (Mackin and Sparks, 1962). This is not infrequent in off-shore
oilfields-Tarzwell (1967) places it at the head of his list of serious oilpollution sources and the Batelle-Northwest Report (1967) notes that
there are about 3 000 active wells off the U.S. coast-but such events
are rarely recorded in the literature. A serious (‘ blow-out ” occurred
off the Texas coast in 1941, but the oil drifted to sea causing no damage
(Bourne, 1968a). The leakage from the Union Oil Company well A-21
off Santa Barbara, California, received much greater publicity and its
effects are still being documented. An initial blow-out at the end of
January 1969 was successfully contained by normal emergency procedures, but oil and gas under pressure were then forced through a
porous layer outcropping to one side of the drilling platform. After
ten days, during which the magnitude of the leakage averaged 21 000