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
|
Source: S.N.
Uchegbu (2002, p.33)
From the above table it is clear that from 1960 to 1985, Nigeria has a total of 3525 cases of oil wells comprising offshore, land, swampy ecological zones. Out of this total 33.3% are offshore; 44.9% on shore and 22.2% from swampy environment. Thus the percentage which is on land is substantial. Therefore, substantial oil spill can be expected from it. None of the others, where offshore drilled or swamp drilled may be free from all accidental spill.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
|
Source:
S.N. Uchegbu (2002 p.35)
The contribution of oil to the economy continued to present to a level of about 80%.
Specifically from 1967 to 1979/80, the breakdown of the petroleum sector contribution to government revenue is shown below:
PETROLEUM
SECTORS CONTRIBUTION TO GOVERNMENT REVENUE. 1967/68 to 1979/80
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
|
Source:
S.N. Uchegbu (2002 p.36)
The table shows clearly that the continued increase
in revenue from the oil sector and as a matter of fact, the contribution has
continued till date.
Apart from the contribution to the economy, the
whole process of petroleum exploration service, refining and marketing provided
employment for thousands of Nigerians (Ofomota, 1997). According to Ofomota,
the oil companies awarded scholarships to some Nigerians. In addition to
providing roads, maps, etc which have been of immense value to Nigerians, they
contribute to the training of Mechanics, drillers, seismic operators and
laboratory operators thus developing the human resources (Udo, 1981).
The
oil industry provides other available energy sources such as petrol, kerosene,
diesel oil, heavy fuel oil, and bottled gas. Moreover, the oil industry
contributes directly to the Federal for more economic growth of the country.
NEGATIVE
EFFCT OF OIL SPILLS
The
problems inherent in oil spills are wide spread in their effects and long
lasting in duration. The effects of oil spills throughout the world may be the
same since the vegetation, waterbodies, soil and groundwater are affected. The
Torray Canyon disaster in 1961 earlier mentioned affected the environment
negatively.
During
the Gulf War, the oil released from Kuwait’s sea terminal was out at about
950,000 cubic metres. The spilled oil polluted the coast of Saudi Arabia
(outreach 1992). Accordingly, there was water pollution, destruction of
vegetation and nesting place for birds and the like. Also, affected were the
lives of aquatic animals living in the sea. Despite the management efforts by
these fairly advanced countries to avert spills, they do not occur frequently
or once in a while.
In
Nigeria, the effect of oil spill according to Ahman (1992) include lost of fish
and aquatic animals, devegetation and other form of ecological damages, loss of
drinking and industrial water, and so on. Ahman observed that when there was an
oil spillage in Bonny Local Government Area (LGA) of Rivers State, it was not
possible then to find portable (drinking) water anywhere in the entire L.G.A.
A
review of the yearly distribution of oil spills, in Nigeria for instance, would
help to drive home the outlined above.
The table below summarizes the
magnitude of the oil spill problem.
YEARLY
DISTRIBUTION OF OIL SPILL IN NIGERIA (1970-1982)
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
|
Source: S.N. Uchegbu (2002 p.38)
As a matter of fact, about 1,678,989.42 Barel Per
Litre (BPLS) of oil were discharged to the environment within a period of 13
years. One could only imagine the tremendous effect on the environment and
particularly on man.
Initially,
it was thought that the oil spills and their negative effect are localized in
the oil producing areas but this is no true as they also occur along oil
pipelines which traverse none oil producing areas enroute to oil dumps and
other stations. However, most of the negative
effects are experienced in the oil producing areas comparative to other areas.
For instance, the Niger-Delta basin with its very delicate riverine and
mangrove ecology serving as a source of food for shrimps with an estimated
yield of about 50,000 metric tone per year is being devastated instantly by oil
spill and pollution problems.
By
and large, the extent of the potential damage that could result from oil
pollution which resulted from oil spill depend on the severity of the oil
spillage, the toxicity of the oil and the type of environment (Ene-Ita, 1984).
The next table is a summary of potential effect of oil spillage, pollution and
oil related activities on the environment.
POTENTIAL
IMPACT OF OIL OPERATION ON THE ENVIRONMENT
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.
|
Source:
S.N. Uchegbu (2002 p.39-40)
Off
all these oil operations, the lessons resulting from spill are greater. Example
of oil spill incidents includes the following:
i.
Shell 21 blowout in 1970
ii.
the Setrap now Elf, Obagi blowout of
1971
iii.
The Agip Oyakama pipeline leakage.
An oil
spillage from well blowout is disastrous as large quantities of oil are
released to the environment. For example, the Funiwa V oil well blowout in 1980
resulted in the release of estimated 8.4 million gallons of oil into the Marine
environment (Oil spill intelligence Report, 1982), the effect can be expected
ranging from surface water pollution, ground water pollution and aquatic life
losses.
There
are other cases of oil spills in Nigeria within attendant environmental effect,
example is oil spill in Uzo in February, 2000 and from that time to present
there were many cases of oil spills and vandalization which resulted in large
degree of serious environmental pollution and acute fuel shortages in Nigeria.
CONTROL
OF OIL SPILL
According
to Ofomata (1997) it would appear that the major obstacle to the solution to
the environmental problem of oil spillage is the ultimate dependence of the
political economy on the profit of the oil industry. However, in spite of this,
solution and control measures have to be proffered. Various methods have been
used to control pollution from oil spills. However, a saying that “prevention
is better than cure”. The preventive measures to curb the incidence of oil
spill are:
(1) Adequate
maintenance of pipeline by prompt changing of old and worn out ones.
(2) Guarding
of pipeline site to prevent vandalization and human induced leaks.
(3) Regular
clearing of the bushes along which the traversed to make the pipeline visible
to human in order to prevent accidental contacts capable of initiating
leakages.
(4) Public
enlightenment as to benefits of safeguarding oil installations and the possible
negative environmental effects in case of oil pollution from oil spills.
When
these preventive measures are taken and either in case of error of omission or
commission, there are oil spill, then remedial measures should be made to
remove the spilled oil from the environment. The method normally used includes
the following:
(1) Spreading
straw on beaches: the use of straws on the beaches allow the straw to absorb
the oil. The oil soaked straws are later collected and burnt. More straws means
more oil being reduced. However, this method depends on the extent of spillage
on the water body.
(2) The
use of detergents: the use of detergent ensures that the oil or the water are
dispersed and the emulsion are flushed off the beaches or water body.
(3) The
use of boom and net: the booms and net are floating barriers that keep the oil
from spreading. In this method, the barriers are substances that limit the
spread of the oil.
(4) The
use of skimmers: skimmers are machines that scoop off oil from a polluted water
body. If the skimmers are in good condition, as much as 300,000 cubic metres of
oil may be scooped up, especially in major spills.
(5) Spraying
hot water at high pressure: when hot water is spread at high pressure over an
oil spill area, oil may be removed possibly by evaporation.
(6) Sprinkling
the shoreline with nitrogen base fertilizer to degrade the oil.
(7) Bioremediation:
the use of bacteria and microbes to feed or degrade the oil.
(8) The
use of chemical dispersants that act like detergents to break up the oil
(Outreach 1992).
(9) Another
effective way of dissluding or removing oil from any surface is called
degreasing. The fairly viscous, non-corrosive chemical that is capable of
performing this function is called dirthbaster (degreaser) (Adedeji, 2000).
Composition
of the degreaser include:
(i)
Sulphoric acid
(ii)
Coustic soda
(iii)
Soda Ash
(iv)
S.T.P.P
(v)
S.L.S
(vi)
Active solvents
(vii)
Essentials
Applications: when an appreciated quantity of this
degreaser is generously applied to then affected surface, it emulsifies the
hydro-carbon based substances, the emulsion that is formed and rinsed is
effluent friendly and not harmful to the ecosystem. The beauty of it is that
after days it grows algae which is a source of nutrients to the aquatic animals.
However,
for a more effective oil clean up, there is the need for a combination of
method.
CONCLUSION
The
oil industry particularly in the area of exploration and exploitation, drilling
well, transportation, e.t.c have had considerable impact on the environment
which man inhabits. The gain from oil has been noted, but the negative effect
seem to equate with the gain. According to reports about N5-6 billion are used annually by the Federal Government to control
pipeline rehabilitation occasioned by pipeline vandalization and spillages.
There
is therefore the need for measures to be taken to prevent oil spillage or
manage oil spillages effectively at the last cost. Our environment and man
should not be allowed to suffer as a result of the presence of oil in Nigeria.
As Ofomata (1997) rightly pointed out “the human environment is the basis for
economic, social and cultural development and it is important that the quality
of our environment be maintained in a good state so as to ensure a high level
of societal performance, preservation of the ozone layers, maintenance and
substance of human, aquatic and vegetation life as well as promotion of
environmental of aesthetic among others.
Baba
Ali Mustapha is with the Department of
Planning/Research, Ministry of Environment, Maiduguri, Borno State.
Reference:
The
research work was based on the work of S.N. Uchegbu, the Associate Dean,
Faculty of Environmental Studies, University of Nigeria, Enugu Campus, from his
book, Issue and Strategies in Environmental Planning and management in Nigeria.
Published by Stotelite Publishers, 27 Ochi Street, Achara Layout, Enugu,
Nigeria.
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