The following dredging equipment are available for hire for work in Nigeria.

1. Trailing Suction Hopper Dredger (1300 m3 hopper capacity)

 2. Trailing Suction Hopper Dredger (4700 m3 hopper capacity).

3. IHC Beaver Wheel Dredger.

If you have interest in any of these machines, please contact us: +234 1 7928166; +234 (0)803 337 8735; or by email to editor@ddhmag.com




Environmental Quality Monitoring


­By C. Chris Anyanwu.

Monitoring of a process is carrying out surveillance over a specific period of time. The type of surveil1ance may range from a few simple measurements to comprehensive statistical sampling and analytical programmes. Measurements may be made visually or with manual equipment, or by relying on sophisticated instrumentation. The way in which samples are taken is as important as the quality of the measurement (analysis) itself. The numerical results of measurement must be correctly interpreted and presented in an appropriate form to interested decision-makers. The results of some monitoring programmes must undergo extensive validation before they can he accepted.

The essence of monitoring, then, is systematic surveillance in accordance with fixed procedures to provide information that can lead to better decision-making about an industrial operation.


In order for any monitoring programme to be successful, reliable results must he obtained and related to the operational conditions of the process over the period during which the measurements were made. There are many reasons why monitoring is undertaken as shown below. Its results provide information that allows appropriate interventions to be made or factual surveillance reports to be prepared. Interventions can be made by plant managers, production or quality control engineers, waste auditors, maintenance engineers, chemical engineers, plant designers, health, safety and environmental officers and government inspectors.

One purpose of this manual is to improve the ability of plant managers to optimize the use of raw materials and energy during production, which leads to the generation of smaller amounts of discharges, emissions and wastes and is an essential element in the cleaner production approach to environmental management.


Numerous different processes and activities are found in industry. Monitoring of emissions and wastes may be necessary for some of the following reasons.

1.2.1 Process optimization

Information from measurements can be used to optimize a process in order to maximize output of a product, improve or maintain its quality, and minimize waste emissions into the environment. Monitoring campaigns may result in simplified measurements that can serve as indicators of other, more complex reactions that are more difficult to monitor. Furthermore, simplified measurements are sometimes used to control the operation of a process or to indicate the need for in-service maintenance. Process optimization is an important component of overall environmental management, and accurate monitoring will improve the level of control exercised over plant parameters. The parameters that are monitored are highly process-specific, but often includes operating temperature, pressure or physical dimensions or movement, in addition to the chemical parameters that are the focus of this manual.

1.2.2 Auditing

Auditing generally consists of a short 'campaign' which is more intensive than usual process monitoring. Its purpose is to support a diagnostic study of process efficiency. As it is often carried out to reduce loss of materials to the environment, it tends to focus on input-output parameters, to allow balance of materials. Further details are available in UNEP/UNIDO Technical Report No.7, Audit and Reduction Manual for Industrial Emissions and Wastes. The audit technique can also be used for energy, water and other consumables. The monitoring activity then focuses on appropriate parameters in those areas.

Monitoring for audits is carried out over a defined period. Modifications to the process usually becomes apparent from an audit; so that, for example, waste streams and their adverse effects on the environment can be reduced. Use of the manual will vary according to the objectives of the process audit but should provide helpful inputs to monitoring activities in all applications.

1.2.3 Compliance with emission standards and consents

Routine monitoring is often used to characterize and quantify plant emissions, as a check on compliance with emission standards or discharge consent requirements. Solid waste leaving a plant may need to be quantified and chemically characterized before transport from the site.

1.2.4 Quality control

Monitoring of raw materials and inputs to a process is often a prerequisite for efficient operation. Inspection of finished products may also reveal process inefficiencies that indirectly lead to the identification of process losses, and hence unwanted pollution. Quality monitoring is highly specific to each process and rarely involves the parameters covered in this manual.

1.2.5 Occupational health and safety

It is of vital importance that monitoring be carried out in work places where there is risk of exposure of personnel to hazardous substances. Procedures and exposure limits for such situations are well documented. Techniques and instruments used for health and safety monitoring can be adapted, in some cases, for measuring the concentrations of gases and particulates.

1.2.6 Environmental reporting

An increasing number of companies prepare regular reports on their environmental performance, including releases to the environment. Some governments require regular reporting of discharges and emissions as a condition for the issuance of permits.


In a plant in which there are many process steps, materials and rejects, it is important to be clear about what is to be monitored and where. The correct choice of process parameters is of course determined by the objectives of the monitoring programme, but the possibilities are still numerous. Selecting the correct parameter, location and frequency, when these are not already stipulated, is a skill that is developed only with practice. A useful rule of thumb is to ask oneself what use will be made of the results and what interpretation may be put on the figures obtained. The general, broad areas that may come under investigation include the following:

within a plant:

- the industrial processes themselves,

- input materials and energy

- residues discharge from the processes

Outside the plant:

- releases to the environment.

- environmental quality and ecological processes.

While environmental monitoring is certainly an important issue, this manual deals principally with monitoring inside industrial plants.

Chapter 2 shows some of the chemical determinants associated with a range of industries and activities. Procedures are given for physical measurements, sampling and analysis. The physical measurement and resources necessary to carry out monitoring at a process plant are described.

Steps in a monitoring Programme

For the purpose of this manual, plant monitoring has been divided into four stages as shown in figure 1.1.

Further information including resources for each stage of a monitoring programme are given in the appendices. Four case studies, with various objectives and of different complexities, are presented in Chapter 4 .

The substance or component of a mixture that is to be determined normally quantitatively, The term provides a distinction between those components of a sample for which measurements are and are not specified.


The paper introduces the topic by highlighting the role of petroleum in the economy and development of the country.

However, attention is drawn to certain attendant negative impacts of oil exploitation on human and ecosystems which should be controlled. Effective solution to this problems calls for an integrated approach which entails forward planning in environmental assets. The concept of Environmental Quality Monitoring is discussed. Guidelines for the control of pollution in oil, gas and petrochemical industries include.

  • The mandatory application of the concept of environmental impact assessment.
  • Establishment of monitoring systems for air, water qualities and hazardous waste management.

The paper also proposes and gives guidelines for the setting up of a national committee to evolve national interim and comprehensive guidelines. Composition of such a committee is also highlighted. The paper concludes by drawing attention to the fact that the cost of environmental protection must be paid either now or in the future. It is much less expensive to install pollution control equipment initially than to convert a production process and add pollution control equipment later. Moreover, it has proved cheaper to spend today’s currency than an inflated one at a later date. The enactment of national interim and comprehensive guideline and their enforcement are the only solutions to long term sustainable economic benefits from the oil, gas and petrol chemical industries.


Nigeria is among the few countries of the world blessed with rich deposits of the “Black Gold’ and other raw materials necessary for oil, gas and petrochemical production. The availability of crude oil, coupled with an inexpensive labour force, and an increased demand for petroleum products have expectedly led to the development of petroleum production capabilities within the country. There can be no question that the discovery and subsequent development of the oil industry in Nigeria have, on balance, brought benefits to its citizens. Today, the petroleum industry has contributed to the country’s rapid physical development of infrastructural facilities and provided revenue for the diversification of the nation’s agricultural and industrial production sectors. However, in spite of these blessings, oil exploration and exploitation, have had attendant negative impact on the human and ecological environment.

Petroleum development and production have resulted in soil degradation, the generation of air and water pollutants, solid and hazardous wastes. Hazardous wastes generated in the petroleum industry potentially pose the greatest hazard to human and animal health since the wastes could be lethal, non-degradable, persistent in nature, biologically magnified or otherwise cause detrimental effects. Several cases of damage to flora and fauna resulting from improper management of hazardous wastes have been documented. These wastes in the environment are often toxic at every low concentration.

It is our conviction, that, as the oil and gas industry in Nigeria grows and become increasingly sophisticated, petroleum processes would produce larger quantities of hazardous wastes. Not only will these waste load grow due to expanding productivity, but also more and newer types of allied industries will come into being with their by-products of toxic hazards leading to greater environmental degradation.

Effective solutions to these problems call for an integrated approach entailing advance or forward planning in environmentally related activities in terms of the long-term conservation of environmental assets. To this end, therefore, it is important to ensure that decision makers on environment as well as planners in both the public and the private sectors are sufficiently conscious as to integrate environmental imperative into development projects such as oil, gas and petrochemical industries. There will also be the need to avoid costly and time-consuming remedial measures. Nigeria has the obligation to protect and preserve its natural environment. In exercising its sovereign right to exploit its petroleum resources, the country has the duty to prevent, reduce and control the degradation of the environment. However, it is a recognized fact that the effective protection of the environment has been handicapped by the absence of comprehensive scientific and socio-economic baseline data that are vital for the enactment of environmental quality guidelines for pollution control.

This paper therefore, is an attempt to provide some basic guidelines which are needed to help the oil, gas and allied industries to incorporate environmental quality monitoring consideration into their development and operational plans. The paper, however, limits itself to guidelines which are intended to serve more importantly as “EARLY WARNING’ to their operators. This is in order to complement the oil spillage contingency plans. The systems proposed here integrates the whole facets of the ecosystem – viz: land, water and air.


In the protection of the natural environmental against pollution/degradation, monitoring can be defined as the measurement of a pollutant or its effects on flora and fauna for the purpose of assessing and controlling exposure to that pollutant. The environmental monitoring process involves regular measurement of physical, chemical and biological parameters to determine the degree to which environmental protection is achieved. Monitoring is used to assess; first, the need for pollution prevention measures, and subsequently the effectiveness of any protection measures introduced. Thus, monitoring programmes have a two-fold objective, firstly, to ensure that regulatory requirements are met, and secondly, to provide management with sufficient data to determine the acceptability or otherwise of any consequent changes.

There are three main categories of environmental monitoring. These are:

Source Monitoring:

This determines the natures and quantity of contaminants or pollutants prior to their distribution in the environment.

Ambient Monitoring:

This also determines the nature, quantity and distribution of pollutants/contaminants in the natural environment - in other words, their distribution in the environment after discharge from the facility.

Effects Monitoring:

This is to monitor environmental changes (if any) caused by contaminants/pollutants.

Source and ambient monitoring are mainly concerned with physical and chemical parameters while effect monitoring must include a biological component as ecological changes are the effects of primary school concern.

However, practical experience from continuous monitoring by the Environmental Planning and Protection Division over the years has shown that ambient and effects monitoring have caused the effect relationships. The monitoring process is strongly inter-disciplinary and if it is to meet targets must be carefully designed and implemented. Hence, it must recognize the requirement for baseline data, with the result that monitoring is initiated at a very early stage of a proposed project.

Baseline information is that which is required for the specific requirements of the project and usually involves supplementing the available data-base. The fact must be emphasised, however, that the oil industry may undertake such work in relation to a project at a particular time and in a particular place, in such a way as to relive the government environmental department; (in this case, the Environmental Planning and Protection Division and other related agencies) of the responsibilities for continuing scientific study of the organism and terrain comprising those ecosystems for whose stewardship they are ultimately responsible.


Environmental Impact Assessment (EIA)


The oil industry being aware of the potential for significant environmental impact and the obvious requirements to comply with the country’s environmental regulations and standards when enacted, it must initiate during the planning and design phases of oil installations, an environmental programme to identify the potential impact resulting from constructions. So far, nationwide investigations conducted by the Event Response Unit of Environmental Planning and Protection Division of the Federal Ministry of Works and Housing, have revealed lack of environmental impact assessment at the inception stages to be responsible for many environmental pollution problems in the oil, gas and petrochemical industries and indeed other major development projects. Example of these, are the Funiwa 5 oil blowout, the Oshika oil spill; there are also, the resultant impairment of health, unhappiness and loss of productivity which are of great cost to all.

Long-term economic effects of industrial pollution must not be neglected. If an industry is allowed to develop in an area of pollution control facilities, eventually the area may deteriorate to a level unacceptable to the local communities who may then move away. Relocation of the population depletes the tax base for public services and results in a further deterioration of the local living conditions. With an added burden, the community is forced to extract more support from the oil industry resulting in higher production cost. Environmental pollution also adds to maintenance cost for homes, public buildings and equipment themselves.

Pollution control through appropriately enforcing guidelines and legislations is a good business practice which a nation cannot afford to neglect. Maintenance of the environment eventually improves that environment as it deteriorates.

Deterioration may occur at a level that is intolerable to flora and fauna and cost the people and the government more than the industry produces. A nation must not sacrifice its customs and good environment to short-term economic gains.

Kaduna Refinery oil seepage, Shell Oil blowout in Umuahia, Gulf Oil spillage in the Escravos, to mention a few, are industrial accidents which have had disastrous impact on the environment. Farmers have suffered great crop damage and could not water their livestock due to the hydrocarbon-laden nature of streams and rivers. Community boreholes which hitherto, served as source of potable water were turned into ‘gasoline well’ as the case in Romi community near the Kaduna Refinery.

However, the major task to be undertaken during environmental impact assessment should include:

  • Review of project facilities and description of planned pollution control equipment.
  • Review of available data; identify and collect additional data needed to describe the existing environment of the project area.
  • Review of applicable Nigerian environmental standards (if any) and assisting in the selection of practical design criteria which effectively reduce the projects’ potential environmental impact.
  • Preparing a discharge inventory to identify the quantity and characteristics of air, water and solid waste effluents generated by the project’s accessories.
  • Performing quantitative and qualitative analysis including air dispersion and noise modeling to determine the potential environmental impacts resulting from the operation of the project and to ensure compliance with applicable environmental standards.
  • Evaluating and assisting in the selection of appropriate pollution control technologies and equipment to limit pollution emission based on the applicable national or international standards.

It is important to add at this juncture that in order to arrest the accelerating environmental degradation of our ecosystem, the environmental planning and protection division (EPPD) introduced the concept of environmental impact assessment (EIA) to the National Council on Works Conference in 1986. It is now mandatory that all projects be preceded by the EIA studies. The memo is now awaiting presentation to the Federal Executive Council for necessary legislative backing. It is envisaged that the passing of this memo into law will make it mandatory for all public and private sector projects to be preceded by EIA at the inception stage.

Establishing Monitoring Systems

Air Quality:

To ensure the proper monitoring and control of air quality, a programme consisting of the following elements need to be initiated and implemented:

  • Meteorological installations around oil, gas and petrochemical terminals, aimed at determining factors which may affect the dispersal of airborne contaminants both at low and high levels.
  • Development and verification of air quality models to help predict possible air quality problems around operational sites.
  • Air quality monitoring programme, utilizing fixed and movable air quality stations, equipped with dependable monitoring equipment and information tapping devices.
  • Laboratory facilities for contaminant/pollutant analyses, tape readout and analysis equipment.
  • Emission monitoring studies for significant sources i.e. anticipated volume, composition and source of all emissions.
  • Design and construction of control accessories such as smokeless flares, gaseous treatment measures, catalyst emission control, etc.
  • Monitoring and improving storage facilities in order to reduce hydrocarbon emissions.
  • Characterization of all air pollution sources, including nature of the emission and factors pertaining to their dispersal potential; in other words, the description of the existing ambient air quality at the project site having regard for the other industrial emission that may be present in the area.

Water quality:

To minimize any potentially adverse environmental impacts on water quality, the following actions should be considered for implementation:

  • Setting up of monitoring stations at up and down streams of water resources adjacent to any oil, gas or petrochemical locations. Remote-sensing facilities for some selected water quality parameters such as pH, conductivity, hydro-carbons, etc.
  • Establishment of central stations for data gathering and collation through radio signals.
  • Daily, weekly effluent sampling programmes to be established in order to detect and held correct eventual higher than normal discharge. Laboratory facilities should be provided with necessary equipment to conduct the analysis of collected samples.
  • Establishment of mobile laboratory units for field in situ determinations.

Solid and Hazardous Waste Management:

The management of solid and hazardous and waste streams calls for, firstly, the description of all solid wastes the oil, gas or petrochemical plant will generate. In other words, the segregation and collection of all the solid wastes generated; and secondly, safe handling/disposal methods. Few technologies are available for treating hazardous solid wastes:


For combustible material whose combustion products do not create air pollution hazards.

Chemical Treatment:

For materials which can be neutralized by chemical addition.


For small quantities of extremely hazardous materials, not readily degradable, encapsulation in concrete, plastic or glass is possible.

Common disposals methods include:


Solid wastes (industrial or domestic) were formerly disposed of in open dumps, but are now generally placed in engineered systems known as landfills. Many hazardous wastes can safely be disposed of with minimal environmental impact if managed. Buried wastes in sanitary landfills and dumps is subject to leach ate by percolating water, and the leach ate may contain several inorganic and organic contaminants. If the landfills are located in relatively permeable strata such as sandstone or fractured rock, leach ate migration may cause ground water contamination over large areas. Such problems can be avoided only by careful evaluation of the hydro-geological features of sites before they are licensed for disposal.

Other disposal methods include dumping at sea and underground disposal, but these are however, presently being discouraged. In addition , it should be mandatory for the oil, gas and petrochemical industries to have functional research and development units whose functions should include shifting emphasis from end of pipe pollution control to evolving plant optimization and designs producing low wastes or no wastes, or less toxic wastes; substituting for alternative process chemicals with less negative environmental impact. They should also produce designs to recycle most of the hazardous wastes.


Since the 1979 seminar, there has been significant concern on the part of the oil industries in Nigeria for environmental protection in their areas of operation. Indeed, the oil companies have made substantial investments in pollution control equipment, research and community development programmes, etc. Individual and group contingency plans have also been established by the oil companies to combat oil spill incidents. However, the lack of enforced regulations has not allowed for significant impact of these collective efforts. Information and series of investigations conducted by the Environmental Planning and Protection Division and the Inspectorate Section (NNPC), and other research institutes continue to show progressive increase in pollution and degradation of our natural resources beyond the carrying capacity of the ecosystem.

It is thus, pertinent to say that in Nigeria today, different official agencies, at national, state, and local government levels, have evolved with considerable overlap with regard to regulating environmental pollution control. The official answer to industrial expansion, in view of environmental contamination or degradation, has been a highly fragmented one, leading to an overlapping of codes, acts, laws and resolutions which on many occasions, have not been sufficiently implemented. Consequently, the public is still at the mercy of the polluter and thereby suffers ill health, crop damage, disruption of means of livelihood, etc.

The urgent need to set ‘interim standards’ to control the high rate of environmental degradation now threatening the basis of our natural resources cannot be over-emphasized. It is for this reason, therefore, that we are advocating that a committee be set up to enact interim national environmental quality standards for air, water, and land pollution control in Nigeria. The responsibility of this committee would be to set interim standards to be operated within 3-5 years during which national baseline studies would be carried out that will aid in formulating comprehensive national standards for pollution control.

It is suggested that the committee should comprise the following:-

A. An inter-ministerial committee consisting of:

  • Environmental planning and protection division, Federal Ministry of Works and Housing.
  • Federal ministry of petroleum resources (inspectorate division, NNPC).
  • Federal ministry of industries.
  • Federal ministry of health.
  • Federal ministry of labour and productivity, (factory inspectorate unit).
  • Federal ministry of agriculture (department of water resources and fisheries).
  • Nigerian institute for oceanography and marine research.
  • Federal ministry of transport and aviation.
  • Representatives of the universities.
  • Federal ministry of justice.
  • States and local government representatives.
  • Representatives of the armed forces.
  1. Technical sub-committees on interim criteria/standards for air, water, solid and hazardous waste pollution control. These sub-committees should be made up of experts in relevant fields.

In addition, the committee should consider for its deliberations, safety guidelines for in-plant operations. It should also evolve strategies for adequate enforcement of these guideline/standards through the framework of an autonomous agency for environmental protection.

We are aware of the enormity of such a task which involves auditing Nigeria’s ecosystem upon which comprehensive guidelines can be enacted. Equally true is the task of determining ambient levels, trends and mathematical modeling simulations that will assist in the formulation as standards for an effective monitoring programme. Nevertheless, it is our conviction that this will assist in the formulation of standards for an effective monitoring progaramme. Nevertheless, it is our conviction that the enormity of such a task has, to an extent, been lessened by the availability of some level of baseline data through the commendable efforts of the NNPC inspectorate division. The EPDD has in the past few years commissioned certain programmes of environmental data gathering. Also, of note, are relevant data scattered all over the nation’s research institutions that need to be collected and collated further for international standards and guidelines. We must not also forget the fact that Nigeria is blessed with adequate technical manpower to surmount this vital task.


The costs for environmental protection must be paid either now or in the future. The most effective method of handling waste products is to build the facilities for processing of certain wastes into useful products. It is much less expensive to install such equipment initially that to convert a production process and add pollution control equipment later; moreover, it has proved cheaper to spend today’s currency than an inflated one at a later date. The clean up at a future time will be costly and difficult. Some damage may be impossible to rectify. There is also the productivity which is of great cost to all.

Long-term economic effects of industrial pollution must not be neglected, if an industry is allowed to develop in an area without pollution control facilities, eventually, the area may deteriorate to a level unacceptable to the local communities who may then move away. Relocation of the population depletes the tax base for public services conditions. With an added tax burden, the community is forced to extract more support from the oil industry resulting in the higher production costs. Environmental pollution also adds to maintenance costs for homes, public buildings and thorough-fares, as well as for the industrial buildings and equipment themselves.

Pollution control through appropriate enforced guidelines and legislations is good business practice which a nation cannot afford to neglect. Maintenance of the environment is much the same as maintenance of machinery, automobiles and other devices. If a nation does not routinely care for the environment, eventually that environment deteriorates. Deterioration may occur at a level that is intolerable to flora and fauna and cost the people and the government more than the industry produces. A nation must not sacrifice its customs and good environment to short-term economic gain.





4th Quarter 2008




Niger Delta: When The Dust Begins To Clear

The white man who came to tap oil in 1958 seems to have run his course in the Niger Delta. It’s 2008 and the world has changed. Both in the larger Nigeria, the Niger Delta and in most other parts of the globe, wherever feelings of being repressed abound, self determinism is increasingly finding its voice.

In the Niger Delta, 50 years of crude oil production has worsted the reputation of the oil majors who gained mining and prospecting licenses from poorly informed civilian regimes and bungling military juntas. Since the turn of the new millennium, all manners of skirmishes now greet the presence and operations of these oil majors and their cronies, minions and hangers-on. Now the communities are on the ascendancy with diverse methodologies but all aimed at the singular goal of appropriating more of the petrodollar. More...

Other Articles & Interviews

Environmental Quality Monitoring

Environment: "How many choppers has DPR got?" - Chief Ogunsiji.

Dredging the Niger Delta: Interview of Ben Efekarurhobo

Role of Surveying in the Dredging Industry

G.B Liman: Of Myth, Reality and Resource Control

Dredging Law: A judgment on the ownership of a sand dredging site by the Court of Appeal.


Dredging Skills Courses 2008

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October 15-18 2008

* Dredge Owners' / Dredge Operators Refresher Course (Oct. 15th)

* Dredge Masters' / Dredge Engineers' / MEAs' Refresher Course (Oct. 18th)

* Dredge Deckhands' 2-day Basic Orientation / Refresher Course.(Oct. 16th-17th)

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