First Urhobo Economic Summit
Oil, Gas and Sustainable Development
November 27-28, 1998
By A.B.M. Egborge,
Professor of Hydrobiology
University of Benin, Nigeria
During the early 1960s, the Atlantic Ocean coastline was some 2 km from the southern end of Marina where many states now have their liaison offices in Lagos. Today, the distance between the water edge and those imposing buildings is easily traversed by Atlantic surge waters. The pumping of sand into the sandy shores was the surest way of wasting money as each tidal or wave movement took with it some dollars spent on the sand.
Stone and concrete paving of shores of rivers and streams stabilises the shore-line. It is thus more cost-effective to develop jetties for take-off and landing of aquatic resources. In addition, paved shorelines prevent erosion and so reduces the amount of silt in water. It also prevents the invasion of littoral vegetation thus retaining the natural width of the waterways. In some developed countries shore-line walls are higher than the natural shore levels thus increasing the effective volumes of the rivers and reducing/preventing annual floods.
Aquatic Weed Control and Dredging
One of the problems of Niger Delta Rivers is siltation. This is the result of the encroachment of the river channel by littoral weeds whose stems and roots serve as sediment traps. Over the years the sediments build up and the littoral region becomes land. In deeper waters the accumulation of sediment reduces the depth of the rivers. Good examples of these occur on the Port Harcourt-Ughelli road. In the Delta State segment of this road from Evwreni towards Patani, it is difficult to determine the channels of the Evwreni River, Onijoh River or the Orhivwiri River (at the 1st, 3rd and 4th bridges respectively) as a result of the profuse growth of aquatic weeds and the near complete siltation of the river bed. Consequently the river banks are overflowed and the surrounding low lands are completely flooded.
If the encroaching weeds are cleared, the river beds dredged to depths of three metres, the river banks paved to a height of 1 foot above the banks, the rivers will not only be more beautiful aesthetically but they will contain more water and reduce flooding.
Flood Control and Fisheries
In eastern [Asian] developed and developing countries, river waters are channelled into a series of lateral concrete or dug in tanks along the river banks for flood control and fisheries. In Nigeria, this can be done in normally flooded lowland plains. For example, a series of water holding tanks, each 50 x 50m x 3m deep on either side of River Ase might reduce the annual floods to zero. These water holding tanks can be stocked with juvenile fish which will grow to table size in 3-4 months with appropriate community management.
Modernisation of Fishing Villages
The primitive state of fishery villages restricts the influx of middle class fishermen who cannot cope with the absence of modern living facilities like flush toilets, pipe borne water, electricity, hospitals, etc. If these coastal fishing villages are developed beyond the present low subsistence levels, fish production would rise consequent upon reduced loss due to spoilage and fish from the water holding tanks.
At the end of the rains in December, farms can be watered through irrigation canals constructed from the water holding tanks. This can continue until the beginning of the next rainy season in March when the water level would have dropped considerably and the fishes cropped. This way more crops can be produced.
Ibia (on Nun River) and Sagbama (on Forcados River) are about 15km apart (crows path) but one needs to do a boat ride of 40km to go from one to the other. Also Isampou (on Bomadi Creek) and Amatolo (on Sagbama Creek) are 25km apart (crows path) but about 100km river distance through Sagbama creek/Forcados River turning south of Ologowa/Agoloma lies between them. With the scarcity of functioning fish processing/preservation facilities, canalisation will greatly shorten distances between production, marketing and consumption centres. One must condemn the irresponsible cannalisation project of Chevron in which Atlantic Ocean waters in the new canal damaged the brackish vegetation at Awoye, Ondo State.
Historically, drinking of river water must be nearly as old as the creation of man although the first book of Moses reports the use of water for irrigation (see Genesis 2-10."And a river went out of Eden to water the garden..." As it was in the beginning so it is today except that municipal water supply schemes also cater for fish farming and industries. This last use of river water produces wastewater and heat which together with solid waste disposed uncontrollable conflict with the use of the water as a municipal source. In the United States of America, Europe, etc as in Nigeria there are standards for surface water quality acceptable for beneficial use (fish farming, irrigation, industries), drinking water from potable public supplies and wastewater effluent standards which regulate discharges of industries into surface waters.
Prior to the arrival of FEPA, Nigeria public water supply standards have been based on US standards published in Standard Methods. In the developed world with the state of the art equipment for determining levels of contaminants in water samples, set standards are met.
In Nigeria, drinking water quality are impaired by run-off discharges, organic and inorganic matter. Rivers/streams in which organic matter is discharged show zonation beyond the point of discharge/mixing. These are:
1. Zone of degradation
* BOD (Biological Oxygen Demand) rises sharply2. Zone of active decomposition.
* DO (Dissolved Oxygen) reduces drastically as a result of satisfying BOD.
* DO reduced to minimumThis recovery from pollution is due to the self-purification capacity (SPC) of all rivers/stream. SPC which assures the assimilation of wastes and restoration of good quality is higher in shallow fast flowing rivers with high re-aeration than in deep/slow flowing rivers with low re-aeration.
* Bacterial and fungal activities increase
* Anaerobic decomposition of bottom sediments produces odours
* Ammonia Nitrogen increase sharply as
* BOD drops
* Animal life decreases and eventually vanish.
In many rural riverine communities river water is the main source of drinking water. In communities close to the Atlantic Ocean high saltiness in river waters makes them unfit for consumption and hence the following statement is applicable in these areas: "Water, water, water everywhere, but none to drink."
* Waters abstracted from rivers for municipal supplies or drinking must be subjected to prescribed laboratory tests to ensure conformity with set standards.
* Where laboratory tests are not possible such waters must be
a. Taken upstream of the discharge of sewage or inorganic chemicalsIndustrial Water
b. Stored in a storage tank and allowed to sediment in its own time or with the addition of alum.
c. Boiled and cooled before drinking. Apart from killing a lot of living organisms including bacteria, boiling expels free carbondioxide and improves the pH (hydrogen-ion concentration).
d. Desalinated in communities close to the Atlantic Ocean.
All industries located close to river banks produce wastes which affect the normal life of the river. There are records of pollution of Warri River by refinery, steel and other industrial effluents, water of rivers, creeks, etc. around the fertilizer plant at Onne in Rivers State and many water systems of the coastal oil producing zones by spilled petroleum. Benin River water of Ogorode, Sapele are polluted with boiling waters discharged from the NEPA thermal plant. Although wastewater effluents standards regulate discharges of industries into surface water, monitoring to ensure compliance in Nigeria appears to be an impossible task.
Political, social and ethnic considerations have influenced the distribution of FEPA outstations. The most pollution endangered part of Nigeria is the oil producing coastal zone. While the zonal office located in Port Harcourt can be justified, the office in Benin meant to cover the oil producing western Niger Delta is misplaced and should be relocated to Warri. For effectiveness local government councils should be charged with the responsibility of monitoring their environments. For this purpose enough money for the establishment of suitable laboratories should be provided on the basis of graded pollution index of each local government area.
Points of discharge of wastewater effluents by industries within the vicinity of the same river should be re-examined with a view to relocating them downstream of the river and on the same side to allow passage of aquatic organisms on the other side.
New Housing Schemes
A visit to Forcados and Escravos tell the same story. Government should as a matter of priority start new housing schemes with 100, 3-bedroom apartments in 10 oil producing communities each year for the next 10 years. Each of the houses should have all modern amenities. With more knowledge and available funds the villages now occupied by oil producing communities will be transformed into cities worthy of their natural endowment before the year 2008 AD.