Due to the negative effect of oil spillage on the environment, recently Nigeria President Muhammadu Buhari flag up campaign for cleaning up of the Ogoni Land in Niger Delta region of the country, he was ably represented by the Vice President Professor Yemi Osibanjo.
Traditional environmental problems have been rife ever since the creation of man. Notable among these are the generation of domestic waste and later, industrial wastes. The generation of domestic wastes is as old as human activity or human existence, and the environmental effects are widespread.
Cases of oil spill have been an isolated issue occurring perhaps randomly in countries using oil as power source or as a source of income. The prominence gained by oil spills is mainly due to its pollution and devastating environmental effects. International recognition of oil spill seemed to have started with the oil spill from the Torrey Canyon disaster of 1967 in a reef in the English Channel. This oil spill with the attendant pollution then attracted the attention of the French and English governments. Further developments in oil activities in other countries of the world resulted in other cases of oil spills in different parts of the globe.
Oil in this context and in all its ramifications connotes petroleum, and all its allied products. Oil spill parse can be said to connote the process of oil accidentally coming out or seeping out from pipe or any other container, hitherto containing oil. Put more succinctly, oil spill is an accidentally or intentional discharge of oil which may reach water bodies (FEPA, 1991) or any other part of land. In this sense, the type of oil spill can include petrol spill, gas spill and diesel spill. The effect of any of these spillages is not negligible.
As already indicated, oil spills occur in oil producing/consuming areas of the world. In Nigeria, cases of oil spill are rife. One is reported by Imerson (1976) to have occurred in Bomu in 1970 where oil was spilled over an area of approximately 108 hectares. Other cases of oil spill in Nigeria is reported by Ogbonna (1981) include the Obagi spill in 1971, Bori spill in 1973 and Obirikom spill in 1977 among others. Oil spillage can occur from the refineries, oil pipelines, deports and pump stations. Activities connected with each of these segments have adverse environmental effects. For instance, in connection with petroleum transportation process is the unavoidable presence of oil leak from the pipes and tankers. We will now consider the possible causes of oil spills in general and Nigeria in particular.
CAUSES OF OIL SPILL
In recent times, oil spill has been identified as one of the greatest single environmental problem all over the world. According to the European Environmental Agency (1998) accidents such as oil spills constitutes a unique class of environmental problem. The agency recognizes oil pollution as resulting from accidental oil spills and natural oil seepage. In essence, there are diverse causes of oil spills. Ahman (1992) in her key note address at the opening session of a workshop during an Environmental Day states that the “immediate causes of the spillages range from break up or damage to oil tankers or storage vessels to sabotage by aggrieved people”. Ofomata (1997) observes that in addition to blowouts, cases of local oil spills can occur as a result of improper handling or mishaps such as burst pipes…..or from continuous seepage from the jetties during the loading of vessels, or from the deliberate action of foreign ships dumping their oil-sodden ballast into our coastal waters and gas flaring.
As a matter of fact there has not been a comprehensive documentation of oil spills by causes apart from random reports. It is even estimated that the contribution from routine actions such as flushing oil tankers at time exceed the level of oil pollution from oil spill.
Within the last few decades in Nigeria, pipeline vandalization in oil producing area or in area traversed by oil pipeline has been on the increase. The issue of oil pipeline vandalization has been increased mainly as a result of rising oil price and petroleum scarcity sometime in Nigeria. The vandals hope to make enormous profit from such act. Many other times, the vandalization is perpetuated by angry villages in the oil producing area who may not be contented with the level of attention paid to them by the government and oil producing companies.
Another cause of oil spill is the leakage of oil from the pipeline. This is normally brought about by old and worn-out pipelines which due to old age starts rusting and eventually leaking oil. In other case, the leakages are caused by vehicular or other accidental contact with the pipeline especially where the pipelines are exposed to the surface.
Oil spill by vehicular tankers are becoming prominent. Apart from the pipeline oil distribution, vehicular tankers play active role in this respect. Many times there are oil spills from these tankers brought about by accidents and leakages. Such accidents when initiated are aggravated by fire outbreak, which then result in more spills and more environmental effects.
Oceanic accidents involving oil carrying ships bring about oil spills. Probably, the Torrey Canyon disaster in the English Channel in 1967 might be a good example. In this disaster, as reported by Vesilind and Pierce (1982) “…..the huge tanker loaded with crude oil plowed into a reef……and almost immediately oil began seeping out. Almost all the oil eventually leaked out and splashed on the beaches. These oceanic oil accidents obtain in areas or countries which use water for oil distribution.
The cases of oil spill in Nigeria depend to a large extent on the distribution of oil wells.
SUMMARY OF WELL DRILLED IN VARIOUS ECOLOGICAL ZONE (1960-1985)
Year
|
Offshore
|
Land
|
Swamp
|
Total
|
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
|
-
-
1
1
28
48
54
65
61
83
78
84
74
91
92
63
41
41
33
42
34
49
41
40
35
19
|
25
20
30
39
52
79
118
76
71
63
53
88
115
112
114
95
59
41
48
48
46
66
47
24
29
23
|
7
4
7
9
14
30
43
26
10
6
24
51
61
34
44
37
48
40
33
41
44
36
28
18
14
25
|
32
24
38
49
94
163
215
165
150
152
155
223
250
237
250
195
148
122
114
137
124
157
116
82
78
67
|
Total
|
1,196
|
1,581
|
748
|
3525
|
On their part Olapade and Olusegun (1997) stated that oil spills result from;
(i) Overflowing storage tanks overturned vehicle or fractured pipeline.
(ii) Smaller but, perhaps repetitive losses of oil which often arise from careless handling of small factories and similar installations.
(iii) The surreptitious dumping of waste oils.
They went further to summarize that causes of oil spill may include pipeline leakage, leakage at drilling rigs disposal of used oil or lubricant, gas flaring, usage of chemicals among others.
EFFECT OF OIL SPILL ON ENVIRONMENT
POSITIVE EFFECTS:
The greatest positive contribution of oil to the development of Nigeria is through the improvement in the economy. The Petroleum sector’s contribution to government revenue over the years is enormous. As at late fifties and sixties, the total dependence of the economy on the oil sector appreciated as shown in the table below:
CRUDE OIL EXPORTS 1958/66
Year
|
Export
in the Sand Ton
|
Value
in Thousand
|
1958
1959
1960
1961
1962
1963
1964
1965
1966
|
245
538
828
2,224
3,368
3,695
5,783
13,019
18,945
|
979
2,702
4,408
11,546
16,739
20,176
32,057
68,097
91,973
|
Fiscal
Year
|
Fed.
Govt. (N’000) Revenue
|
Revenue
from Petroleum (N’000)
|
%
share of Petroleum total revenue
|
1967/68
1968/69
19/69/70
1970/71
1971/72
1972/73
1973/74
1974/75
1975/76
1976/77
1977/78
1978/79
1979/80
|
300,197
299,986
435,908
755,605
1,410,911
1,389,911
2,171,370
5,177,063
5,252,297
5,756,328
7,652,500
6,815,200
11,809,100
|
41,884
29,582
75,444
196,390
740,185
567,151
1,549,383
4,183,816
4,568,425
4,833,713
6,459,000
5,458,500
9,869,800
|
13.95
9.86
17.31
25.99
52.46
41.45
71.36
80.81
86.98
83.97
84.04
80.01
83.57
|
S/No
|
Year
|
No.
of Spills
|
Net
Volume (BBLS)
|
1
2
3
4
5
6
7
8
9
10
11
12
13
|
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
|
1
14
41
59
105
128
128
104
154
157
241
233
46
|
180
15,111
15,390
95,580
65,714
56,854.82
20,023
31,144
97,250
630,405
558,053
22,840
34.4
|
Total
|
13
years
|
4,581
|
1,678,989.42
|
Gas
Operation
|
Potential
Impact on the Environment
|
Gas
Flaring
|
Causes
very high temperature with excessive noise and vibrations around the area.
The excessive heat scorched and withered some vegetation especially
palm-trees. Air pollution from the incomplete combustion of the gas flare is
noticed.
|
Oil
Drilling/Leakages
|
-Accumulation
of toxic material from drilling materials.
-
Oil pollution of the sea, beaches or land.
-
Destruction of fisheries ground for some marine fishes.
-
Alteration of the taste of fishes.
-
Killing of bottom dwellers.
-Pollution
of underground water.
|
Flat
form and tank forms
|
-
Water and land pollution from sanitary.
-
Waste, used and leaked lubricating oil.
|
Gas
Flaring (extra)
|
-
Suppressed the growth and flowering tree
-
Destruction of mangrove swamps and salt.
-
Aesthetic devaluation.
|
Loading,
location spillages (onshore and offshores)
|
-
Spillage during loading operation with all its accompanying effect on the
fauna and flora.
|
Transportation
by pipeline , tankers
|
-Sedimentation
along pipe line routes.
-Water
pollution from consequences of leaks from fracturing or breaking of pipes
cause by mental fatigue, trawlers and dredges or sea floor failure, or
sabotages.
-Air
pollution by transport tankers.
-Destruction
of environmentally sensitive areas e.g. lowlands, where enturies, wetland and
sand dumes fields exist.
-Erosion
and flooding.
|
Storage
Deports (spillage)
|
-Land
pollution from chemical cons and drums.
-Air
pollution from storage tanks.
-Air
pollution from gaseous fumes during loading.
|
Refinery
|
-Water
pollution by organic and inorganic pollutants including oil and grease.
|
Health
Effects
|
-In
almost all cases the health of man is affected.
|
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