CENTRE FOR ENVIRONMENTAL IMPACT ANALYSIS · PDF fileThe Centre for Environmental Impact...

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CENTRE FOR ENVIRONMENTAL IMPACT ANALYSIS

DRAFT REPORT ON

EFFECTS OF OIL AND GAS EXPLORATION AT THE JUBILEE FIELD ON WATERQUALITY IN OIL RICH COASTAL COMMUNITIES IN THE WESTERN REGION,

GHANA.

WITH FUNDING FROM GRAP SPECIAL PROJECT FUND FOR OIL AND AGSUNDER AUSPICES OF OIL WATCH GHANA.

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1.0 Introduction

Ghana’s Discovery of Oil in June 2007 is not the first time oil exploration has taken place in thecountry. Oil exploration dates back to almost a century when oil was discovered in the saltpondfields. However, Ghanaians nave been more expectant and looks forward to Ghana becoming anoil producing country since the discovery of oil in commercial quantities at the jubilee fields.

The oil find is seen as a blessing by most Ghanaians’ because the certainty of revenues that willbe generated from this sector is high and also a boost in the country’s economy. In a World Bankreport dated November 2009, it is certain that the six of government revenue derived from the oiland gas sector will dwarf the revenues currently generated by the mining sector. The World Bankbases its projection of potential government revenue on estimated oil reserves of 490 millionbarrels in the jubilee field. Assuming a price of US$ 75 per barrel, the World Bank estimate putspotential government revenue from oil at an annual average of US$ 1 billion between 2011 and2029. In addition to this, the associated production of gas is estimated to generate revenuesaround one tenth oil revenue amounting to approximately US$ 120,000 annually.

According to figures from GNPC, Ghana’s projected take from the Jubilee field will be in therange of 38-51% of total oil revenue. Job creation and increase in employment opportunities areexpected to go up. As oil and gas companies may hire local companies as sub contactors orservice deliverers. Indirect employments may also be generated in local communities.

These and other economic and financial analysis of the oil and gas sector indicates significantpotential increase in revenue for Ghana. However, the impact of oil and gas exploration andextraction on the socio-economic, environmental and health of surrounding communities as wellas the entire country have to be considered and not only the revenue that will be generated fromthe sector.

1.1 Project background

The find of oil though seems as a blessing, because of the numerous benefits the country is goingto derive from it like, creating more jobs, increasing the country’s revenue and also bringingGhana into the limelight to attract more investors into the country, has also gotten somechallenges that there is the need for them to be addressed. Problems associated with extractivesectors like the ‘Dutch disease’ whish is over concentration on the oil and gas sector leavingother natural resource base sectors to diminish in returns in terms of concentration and revenuesgenerated from those sectors. Consequences like environmental degradation, resource wars, badgovernance, socio- economic issues like gender issues and others are some of the problems thatneed to be addressed.

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Oil Watch Ghana, a new coalition on oil and gas which seeks to ensure sustainable and efficientoil and gas management in Ghana undertakes this project to deepen knowledge about issuesassociated with the oil and gas sector. Other sectors of the economy like cocoa production andexport, timber and other forest products export, fishing and other agricultural developmentscould be threatened with the arrival of the oil production sector for the competition for land andother resources, possible dislocation of other trade opportunities if not a total government neglectof the earlier sectors to focus on oil and gas. The large rural population that depends onagriculture and fishing to earn a living in the western region and other oil find locations in Ghanaare agitating on their sustainability and how this new oil extraction sector will affect theirlivelihood. The social, culture and gender values of Ghana and the immediate geographicalsurroundings and communities in the oilfield are of much concern with the infiltration of theirtraditional norms and regulations with the influx of different culture and global trends. This canhamper development strategies that respect social responsibilities and the development ofaffected communities. Oil production and the revenues generated from it pose very seriouschallenges to governance, environmental sustainability and macroeconomic management. It isfrom this background that this project has been undertaken to bring out the challenges and somecoping strategies.

1.3 Rationale and justification for the study

The oil find areas in Ghana including Nzema East Municipal, Secondi Takoradi Metropolitan,Ellembelle, Ahanta West, Jomoro, Agona West District Assemblies and their surroundingcommunities like cape three points, half Assini, Ellembelle, Princes Town, Axim, Discove,Busua, Miamia, Akwidae,Wotera, Sekonde, Eziama, Nkroful and Secondi-Takoradi are the areaswhich are most likely to be affected by these oil and gas activities. The impacts that may resultfrom the actions and inactions of these multinational oil companies could result in manyunhealthy environmental and socio-cultural situations like:

• Grabbing of farmlands for petroleum production and its auxiliary services bypotential investors and local business operations and its potential relocation andsocio-cultural challenges.

• Potential degradation of the environment including land degradation, marinewater pollution, gas flaring effects like increased green house emissions , poorpublic health and safety.

• Increase prevalence of infectious diseases like, HIV, malaria, tuberculosis andother oil extraction and pollution related problems and diseases such as skinrashes, eye inflammatory diseases, respiratory tract infections and others.

• Social conflict and increasing harassment and intimidation of inhabitants by oilcompany personnel and state security.

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• Increasing unemployment of the local people, widening poverty gap andunderdeveloped infrastructure within affected communities.

It is within the above context that this study was designed to conduct evidence based research onthe effects of oil and gas exploration on water quality in oil rich coastal communities in theWestern Region, Ghana. This evidence based research would generate data that would build thecapacities of citizens, to engage government (local and national levels), oil companies and otherstakeholders on the opportunities and potential (positive and negative) impacts of oil productionin the oil rich communities.

This study also seeks to make communities and civil societies aware of possible implications ofoil and gas extraction on the marine ecology (UN Convention on oil pollution prevention) inGhana and the implications of indiscriminate land scramble and grablling on user rights offarmers, agriculture and food security as a whole and the effect of oil and gas on theenvironment, land policy issues, livelihood and food security. For example, between December2009 and May 2010, KOMOS energy a member of the Jubilee partners on three differentoccasions discharged Low Toxicity Oil Based Mud into the marine waters of Ghana. Dischargeof oil drill cuttings including low toxicity oil based mud has serious implications on marineecology as shown in fig. 1.0 below.

Fig. 1.0 Apartially

discomposed whale found on the shore of Half Assini. (Source: Fishermen Association inHalf Assini during the commencement of the Jubilee Operation)

The Centre for Environmental Impact Analysis (CEIA), a member of the OIL WATCHCOALITION, seeks through this research work to investigate the effects of oil and gasexploration on marine water quality and other water bodies in the study area. The study seeks to

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come out with strategies of pollution prevention to mitigate the effects of continuous oil and gasexploration in the study area. CEIA seeks to promote environmental and gender audits andaccounting to also environmental and social impacts issues with the identified oil extractioncompanies. The results of the study would serve as a platform for oil watch coalition membersto:

- Engage government and private sector (oil extraction companies) on socio-cultural, gender and environmental related issues on oil and gas.

- Establish a baseline on community interests, floral and faunal resources,knowledge and participation in oil governance for comparative analysis of projectimpact (positive and negative). This will cover relevant areas like land (includingwater) management of hazardous waste and the anticipated impacts on urban andrural communities and livelihoods

- Train 10 selected local communities on the benefits of oil and gas extraction,environmental pollution threats and indicators, indicators/pollutants identificationand response mechanism,

1.4 Aims and Objectives

The overall aim of this project is to collect evidence of effects of oil and gas extraction on waterquality, fisheries resources, flora and fauna species; as well as investigate other issues such assustainable environmental management, transparent and accountability (good governance)resulting from oil and gas extraction.

The specific objectives of this project are:

- To determine the levels of the following water quality parameters pH, turbidity,colour, conductivity, total dissolved solids, total suspended solids, sodium,potassium, calcium, magnesium, total iron, ammonium, chloride, sulphate,phosphate, manganese, nitrite, nitrate, total hardness, total alkalinity, calciumhardness, magnesium hardness, fluoride, bicarbonate, carbonate, zinc, cadmium,lead, arsenic and copper.

- To determine the concentration of oil and grease in the water samples; and to usethis concentration as an indicator of oil pollution from the oil and gas exploration.

- To compare the levels of physic – chemical parameters, cadmium, arsenic, zinc,copper and oil/grease in the water samples with World Health Organization(WHO) and Ghana Environmental Protection Agency (GEPA).

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CHAPTER TWO

LITERATURE REVIEW

ENVIRONMENTAL IMPACT OF OIL AND GAS EXPLORATION

2.0 Chemicals in petroleum

Petroleum is a naturally occurring toxic, flammable liquid consisting of a complex mixture ofhydrocarbons of various molecular weight and other organic compounds and is recovered mostlythrough oil drilling. It is refined and separated most easily by boiling points into a large numberof consumer products like gasoline, kerosene, asphalt, chemical reagents use to make plasticsand pharmaceuticals.

Liquefied petroleum gas (LPG) is part of petroleum but it is a mixture of lighter hydrocarbonslike methane, ethane, propane and butane. The other organic compounds found in petroleum arecarbon, nitrogen, oxygen and sulphur. There are also other trace metals such as iron, nickel,copper and vanadium.

2.1 Impact of petroleum exploration on the environment

The effects of oil and gas exploration on the environment are numerous and according to theNiger delta environmental survey final report, the Niger delta which is a well endowedecosystem and is one of the highest biodiversity concentrated areas on the planet, with morespecies of fresh water fish in west Africa could experience ea loss of 40% of its inhabitableterrain in the nest thirty years because of extensive dam construction by oil explorers in the area.

Gas flaring which is normally done during exploration releases gases such as nitrogen dioxide,sulphur dioxide, volatile organic compounds like benzene, toluene, xylene and hydrogensulphide. The flares coat nearby lands with soot and damage adjacent vegetation.

Waste water that is the water produced as a byproduct of oil drilling, contains polycyclicaromathic hydrocarbons which in high concentrations are lethal to marine life. Other by productsof oil drilling is mud, slimes and sludge. Sludge contains TENORM (technologically enhancednaturally occurring radioactive material) that can be lethal sometimes. The dispersal method forthese waste include dumping them on farm sites and tailing ponds which can be fatal tomigratory birds and the vegetation.

In the extraction phase of oil and gas, road and infrastructure are constructed and these are oftendone in pristine areas. The infrastructure constructed allow loggers, ranchers and displaced

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people to access previously impenetrable forest or wilderness area leading to further destruction.The extraction process also leads to leaks and seepages that cause massive environmentalpollution and health problems.

The effects of extraction on marine life are enormous and the effects are caused by either thephysical nature of the oil or the chemical composition. Clean up operations during extractionaffect the habitat of plants and animals. Birds that feed by diving or form flocks on the sea andmarine life on shorelines are affected.

The FPSO facility and associated support vessels and export tankers according to the jubileefield draft environmental impact analysis report, will produce a series of discharges includingblack water, grey water, produced water and miscellaneous discharges (i.e. bilge water, deckdrainage and cooling water).

2.2 Effect of oil extraction on fishing and farming activities and the marine environmentOil extraction be it offshore and onshore has a lot of effects on existing activities in the areawhere the oil is being extracted, notable among them are farming and fishing. According toLegborsi (2007), the people of Ogoni in the Niger delta of Nigeria are experiencing thedestruction of the traditional local economic support system of fishing and farming. Thecombination of the effects of oil spill and acid rain resulting from gas flaring has been soildegradation which affects crop yield and harvest. Fish are driven away from in-shore or shallowwaters into deep-sea as a result of flaring.The ultimate result of this is the poor crop yield as thesoil has been rendered infertile and poor fish catch, as most fish has been driven into deepwaters and the Ogoni people do not have the fishing gadgets to go into deep-sea fishing. Thewhole impact of this is food shortage and which has affected the ability of most families to feedthemselves. As a result of the above, Ogoni that was once the food basket of the Niger Delta, isnow fully dependent on imported food.

Produced water which is a by-product of the processing of hydrocarbons from undergroundreservoirs and occurs naturally in these reservoirs that are normally produced as a liquid with theoil or as a vapour in gas. These are mostly discharged to the sea following treatment to reducethe concentration of dissolved oil to at or below 29 mg/l maximum monthly average and 42 mg/lmaximum (jubilee field draft). The produced water being dumped in the sea contaminates andpollutes the water and therefore causes harm to marine organism and the ecosystem in whole.

Produced water, having been in contact with various rock strata at elevated pressure andtemperature, contains many soluble components including barium and the radioactiveintermediates of the uranium and thorium decay series. As the water is produced from the wellsthe temperature and pressure decreases creating conditions in which the barium and radionuclides can co precipitate inside separators, valves and pipe work, forming an insolublenaturally-occurring radioactive material (NORM) scale. Some of the soluble radio nuclides andparticles of NORM scale can pass through the system and be discharged with the produced waterinto the sea which tends to have negative effect on marine organisms.

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2.4 Oil spillage and it effect on the marine environment

Oil spillage which is one of the accidental occurrences of oil extraction has a major effect on theecosystem. According to the final report of the environmental survey of the Niger delta, largetracts of the mangrove forest has been destroyed. The spills have taken out crops and aquaculturethrough the contamination of ground water and soil. Offshore spills which are usually muchgreater in scale contaminate coastal environment and causes a decline in local fishing production.Tanker ship accidents that cause oil spills have damaged natural ecosystems in Alaska, theGalapos Island in France and many other places. Oil spill quantities from a few hundred tons to afew thousand tons have already proven to have a big impact on the ecosystem such as the ExxonValdez oil spill. Oil spills at sea are more damaging than those on land. When oil is spilled, mostof the volatile compounds evaporate quickly. The oil, however, remains floating on the surfaceof the water, and starts to disperse, forming a very thin film which can cover large areas of water.Oil spills affect marine life which live, hunt, or travel in the area covered with oil. Differenttypes of marine life are impacted differently, depending on their physiology and habits. Thecompounds left behind after the volatile compounds play a large part in why oil spills affectmarine life, since many of them are toxic, dense, and bio accumulative.

One of the most direct ways in which oil spills affect marine life is by essentially suffocatingplants and animals. Marine plants can be covered in a film of oil which prevents oxygen andwater exchange, causing the plants to die. Marine life which feed on this vegetation will in turnstruggle to survive. Coatings of oil on the flesh of birds and mammals can literally kill themthrough suffocation. Oil spills also affect marine life such as birds by stripping the water resistantcoating from their feathers. A bird weighed down by oil may have difficulty flying, and willdevelop hypothermia as a result of exposure to extremely cold water. Mammals also suffer, as oilcan remove water resistant compounds from the coats of furred marine life like otters and seals.Oil spills affect marine life like filter feeders by concentrating in the flesh of these animals.Clams, mussels, and oysters may quickly accumulate toxins which can kill the animals or bepassed on along the food chain. Human consumers often complain that shellfish harvested froman area impact by an oil spill taste heavy and oily. Animals that rely on these filter feeders forfood may become sick and die as a result of consuming them. When oil spills affect marine life,it usually happens at multiple levels of the food chain, representing a lot of work to fix theproblem. The inhalation and ingestion of compounds related to oil spills can also harm marinelife, both in the long and short term. In the long term, oil spills affect marine life by interferingwith the ability to breed, reproduce, grow, or perform other vital functions. Some of the effectsof oil spill on the marine environment include:

(a) Decrease of fisheries resources or damage to wild life such as sea birds and marine mammals,

(b) Decrease of aesthetic values due to unsightly slicks or oiled beach

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(c) Modification of marine ecosystems by elimination of species with an initial decrease indiversity and productivity and

(d) Modification of habitats, delaying or preventing re-colonization.

Sources of oil input to the marine environment are often divided into natural, sea-based and land-based sources. In the NRC report, the perspective of "following the oil" is used, with four maincategories of sources: discharges through natural seeps, discharges during the extraction of oil,discharges during the transportation of oil, and discharges during the consumption of oil(including both sea-based and land-based sources). There are also other ways of placingaccidental or operational/deliberate discharges of oils into different main categories.

2.5 Oil extraction and atmospheric emissionsAlthough atmospheric emissions accompany most of the oil and gas operations, this factor hasnot gained any special attention in the context of offshore development. In some areas of onshoredevelopment e.g. western Siberia and near astrakhan in Russia, this source of pollution poses aserious threat to water and onland ecosystem and to human health (Patin 1999).From the environmental survey of the Niger delta, gas flaring as a form of emission releaseslarge amount of methane which has a high global warming potential. Nigeria is estimated to haveemitted more than 34.38 million tons of methane accompanied by carbon dioxide in 2002.

Atmospheric emissions takes place at all stages of oil and gas industry activities. The mainsources according to Patin (1999) include:

• Constant or periodical burning of associated gas and excessive amounts of hydrocarbonsduring well testing and development as well as continuous flaring to eliminate gas fromstorage tanks and pressure controlling systems.

• Combustion of gaseous and liquid fuel in the energetic units ( diesel- powered generatorsand pumps, gas turbines, internal combustion engines on the platforms, ship and onshorefacilities).

• Evaporation or venting of hydrocarbons during different operations of productiontreatment, transportation and storage. In spite of the prohibition of flaring of oilassociated gases, it remains one of the major sources of atmospheric emissions in theworld.

Components of atmospheric pollution caused by oil and gas development include gaseousproduct of hydrocarbons evaporation and burning as well as aerosol particles of the unburnedfuel. From ecological perspective, the most hazardous compounds are nitrogen and sulphurdioxide, carbon monoxide which is the product of incomplete burning of hydrocarbons. Theseinteract with the atmospheric moisture, transform under the influence of solar radiations andprecipitate onto the land and sea surface to form fields of local and regional pollution. Accordingto the draft environmental impact analysis report of the jubilee field the phase one activities,including well completion operations, the subsea equipment and FPSO facility installation,commissioning and operation, export tanker operation, flow line and umbilical installation andsupport vessel and helicopter operations will emit greenhouse gases and varying amounts of

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other pollutants such as carbon monoxide (CO), oxides of nitrogen (NOx) and sulphur (SOx),volatile organic compounds (VOCs) and particulate matter(PM).

2.6 Health risk associated with oil extraction activities

Oil extraction can impose a lot of health risk to individuals like pollution of underground water.In Nigeria, according to the survey conducted in the Niger delta, drinking water is usuallycontaminated. The numerous hydrocarbons and chemicals present in oil represent a carcinogenicrisk. There are some studies, although few in number, which describes link between extractivepetroleum activities in remote areas and health problems for local indigenous people, such aselevated rates of spontaneous abortion, cancer and deterioration of other indices of health in theEcuadorian Amazon. Toxins in oil can also cause cancers and other illnesses in the long term. Ifleft untreated, the area around an oil spill can be denuded of life Hazards to man through eatingcontaminated seafood, Explosions from pipelines have also resulted in injuries and in some casesdeaths of people in the local communities. According to a UNCTAD (2007) report, because theproducts of the oil industry are mostly combustibles and explosives, accidents such as fires andexplosion can have serious effects. In October 1998, for example, a pipeline leak led to an oilflood near the village of Jesse in the Niger Delta and ultimately resulted in an explosion in whichover 700 people, mostly women and children, were reported to have died (US Non-Governmental Delegation to the Niger Delta 1999 report, Darkwah 2010) In addition to thehealth risk for the local communities from environmental pollution and accidents as a result ofoil explorations, the influx of migrant populations also brings health problems to the localpopulation through the introduction of new diseases. New settlers and migrant workers in someinstances become vectors through which new diseases hitherto absent, are introduced into thelocal communities. The UNCTAD (2007) report cites the case of the Ecuadorian Amazon wherethe new settlers and migrant workers of ChevronTexaco introduced various diseases to the localpopulation. For example, a report by a US Non-Governmental Delegation (1999) that visited theNiger Delta indicated that in the local communities there, diseases such as respiratory diseases,skin rashes, coughing up blood, tumours, gastrointestinal problems, different kinds of cancersand malnourishment were not uncommon.

2.7 Effects of spillage of low toxicity oil based mud

The liquid and solid waste associated with the petroleum hydrocarbon operations include wastesderived from drilling activities, those derived from maintenances of machines and equipment andthe wastes derived from life on platform Imevbore (1979). The exploratory wastes generatedduring the drilling activities include well cuttings, drilling muds, formation water, cement slurryresidue, oil cushions e.t.c. Drill cuttings are pieces of the formation being drilled that arereturned to the surface with drilling fluid. Solids control equipment separates the cuttings fromthe drilling fluids so that the drilling fluid can be reused. The cuttings then become a wastestream from the drilling process.

Prominent among the composition of the exploratory wastes are the aliphatic hydrocarbons,polynuclear aromatic hydrocarbon (PAH) and heavy metals such as arsenic, cadmium,

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chromium, lead and mercury (Valkonic, 1978; Darley, 1988; Arscott, 1989). These wastes arediverse in their toxicities and impacts on the biota of the environment (Odiete, 1999).

According to American petroleum institute (API) (1989), both the well cuttings and the drillingfluids constitute about 2% of the total exploratory wastes. It is well known and generallyaccepted that the drilling muds and cuttings generated during the off-shore drilling activities aredumped into the sea.

Owing to their sizes (that is, 2 – 5 mm) almost all the particles of the cuttings disposed on the seaare deposited below the rig in a thin uniform layer. The disposed well cuttings becomes aproblem to the environments – offshore or onshore (Richard, 1993), when they becomeimpregnated with oil during drilling while Reis (1996) believed that many of the additivescomponents in the disposed drilling muds can be toxic to the environment.

CHAPTER THREE

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METHODOLOGY

3.0 Sampling techniques

Random sampling techniques were adopted in selecting three districts within the six frontline oilproducing districts in the western region. The selected districts are Jomoro, Nzema EastMunicipal and Ellembele District. In each district/ municipality, three communities were selectedusing random sampling techniques. In each community, water samples were collected fromstreams/rivers using random sampling techniques. In addition to the random samplingtechniques, purposive sampling techniques were also adopted in collecting water samples fromthe Jubilee Field and areas where residents/fishermen perceived to be polluted by the operationsof the Jubilee Field. Table 1.0 below gives the list of communities where the water samples werecollected.

Table 1.0 List of communities where water samples were collectedS/No. Name of community District

1. Half Assini Jomoro

2. Asanta – River Asanta Ellembele

3. Ellembele Blay Ellembele

4. River Ankobra – Axim Nzema East

5. Rig – Jubilee Field Nzema East

6. River Ankobra – Asanta Ellembele

7. Sea Water – Half Assini Jomoro

8. Axim – River Ankobra Nzema East

9. River Ankobra – Axim Nzema East

3.1 Sample collection, preparation and storage

Water samples were obtained from rivers, streams, boreholes/wells and tap water in the studyareas. 1.5L of the water samples were collected into sampling containers that has been rinsedwith 1:1 conc. HNO3 acid and double distilled water and fixed with identification labels. Thesamples were stored in an ice – chest at a temperature of 4_C and later conveyed to WaterResearch Institute of Council for Scientific and Industrial Research (CSIR – WRI) for laboratory

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analysis. pH, turbidity and conductivity of the samples were determined using hand potable pH,turbidity and conductivity meters respectively on the field (AWWA, 1998). Two samples werecollected from each sampling point. One was acidified with 10% nitric acid for the analysis ofheavy metals whilst the other was used for the physicochemical analysis. The other sample wasused for the physic – chemical analysis. In the laboratory, the acidified samples were filteredusing Whatman’s no. 0.45µm filter paper. The 0.45µm membrane filter paper was used becausethe analyte of interest in this work is the total dissolved metals. The filtered samples and theunfiltered samples were stored in the refrigerator at 4_C for further analysis (APHA – AWWA,1998).

3.2 Digestion of samples for the analysis of As, Fe, Mn, Cu, Pb, Cd and ZnOne hundred millilitres of the well – acidified water sample was mixed with 5ml conc. HNO3and 5ml conc. H2SO4. This mixture was then heated until the volume was reduced to about 15 –20ml. The digested sample was allowed to cool to room temperature. It was then filtered throughWhatman’s 0.45µm filter paper. The final volume was adjusted to 100ml with double distilledwater and stored for analysis (APHA – AWWA, 1998).

3.3 Analysis of samples for As, Fe, Cu, Mn, Cd, Pb and ZnThe method for the analysis of the water samples in this work was based on standard methods foranalysis of heavy metals adopted by the US Environmental Protection Agency and AmericanWater Works Association. The determination of the heavy metals in the samples was carried outby the Heavy Metals Laboratory of the Water Research Institute (WRI) of Council for Scientificand Industrial Research (CSIR). The concentrations of Fe, Cu, Mn, Cd, Pb and Zn weredetermined using flame AAS (Atomic Absorption Spectrophotometer) Perkin Elmer model 520after double distilled water has been used to zero the instrument, the concentrations of Fe, Cu,Cd, Pb, Mn and Zn in the blank were also measured and then followed by the determination ofthe concentrations of Fe, Cu, Mn, Cd, Pb and Zn in the digested samples. The concentration ofarsenic in the water samples were determined using flame AAS Perkin Elmer model 520 coupledwith arsine gas generator. In the determination of arsenic concentrations in the water samples,5ml of 0.5% NaBH4 and 5ml of 0.5M HCl were added to each of the digested sample to reduceall the arsenic in the samples to an arsine gas, in the arsine generator, which was coupled to theflame Perkin Elmer model 520.

3.4 Analysis of physico – chemical parameters

The physico-chemicals parameters including pH, turbidity, conductivity, apparent colour,sodium, potassium, calcium, magnesium, ammonium, chloride, sulphate, phosphate, nitrite,nitrate, total hardness (as CaCO3), total alkalinity (as CaCO3), calcium hardness (as CaCO3),magnesium hardness, fluoride, bicarbonates, carbonates, total suspended solids and totaldissolved solids were also determine by the Potable Laboratory section of Water ResearchInstitute of CSIR. The pHs of the samples were determined using Jennway pH meter model3510, after the meter has been calibrated with pH buffer solutions of 4, 7 and 10.The turbidity’s of the samples were also determined using Hach Turbidimeter model 2100Pwhilst the electrical conductivities, total suspended solids and the total dissolved solids of thesamples were also determined with Jennway Conductivity meter model 4520 (AWWA, 1998).

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The concentrations of sodium and potassium in the samples were determined using the flamephotometer whilst the concentrations of ammonium, sulphate, nitrite, nitrate and fluoride in thesamples were determined using UV spectrophotometer. Total alkalinity, chloride, total hardness(as CaCO3) and magnesium hardness were determined using titrimetric method (AWWA, 1998).

3.5 Determination of oil and grease in the samples

To 100 mL of the sample was added 20 mL of acetone in a separating funnel. The mixture wasshaken vigorously for 20 mins after which it was allowed to settle into organic and aqueouslayers respectively by clamping the funnel in a retort stand for 10 mins. The aqueous layer wascollected into a separate beaker and the organic layer drained into a pre – weighed evaporatingdish. The aqueous layer was then transferred into the separating funnel and 20 mL of acetone.The mixture was shaken thoroughly for 20 mins, after which it was allowed to settle intoaqueous layer and organic layer. The organic layer further was drained into the pre – weighedevaporating dish whilst the aqueous layer was also drained into the beaker. The process wasrepeated for three consecutive times. The organic layer in the evaporating dish was evaporated todryness on water bath at 95°C. The dish was allowed to cool to room temperature and re –weighed again. The difference in weight of the evaporating dish was mass of the oil/grease in thesample after which the concentration of the oil/grease in the samples was determined (AWWA,1998).

3.6 Quality Assurance

Reproducibility and recovery studies were conducted using certified reference material withconcentration of 1µg/g. The percentage of Fe, Cu, Mn, As, Cd, Pb and Zn recovered in therecovery studies ranges from 95% to 100% for Fe, Cu, As, Mn, Cd, Pb and Zn respectively.Similar results were obtained for the reproducibility studies. The percentage of Fe, Cu, As, Mn,Cd, Zn and Pb recovered in the reproducibility studies ranges from 96.3 to 99.6% (standard error± 0.005 to 0.560). The standard error was less than 1, suggesting that the method employed toanalyse Fe, Pb, As, Cu, Mn, Cd and Zn was reproducible. The distribution ration for the solventextraction was 1.0 which suggests that the method used for extraction of oil/grease from thewater samples was reproducible.

CHPATER FOUR

RESULTS AND DISCUSSION

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4.0 Mean results of the physico – chemicals parameters of the water samples

The mean results of pH, conductivity, colour, total dissolved solids, total suspended solids,sodium, potassium, calcium, magnesium and ammonium in the water samples from the studyarea is presented in table 1.1 below.Table 1.1 Mean results of physico – chemical parameters in the water samples in the studyareas

Parameters

Sampling PointpH Colour Cond

-µS/cm

TDS –mg/L

TSS –mg/L

Namg/L

Kmg/L

Ca

mg/L

Mg

mg/L

NH4-Ng/L

Elembele 1 (RiverAsanta Upstream)

7.23 25 1410 776 3.0 220 3.46 40.1 34 <0.001

River Ankobra–Axim

8.43 15 62000 34100 <1.0 8846 120 601 1312 <0.001

Rig 1 (North of theRig)

8.40 2.50 63600 34980 <1.0 11248 132 441 1263 <0.001

Elembele 2 (RiverAsanta Downstream)

7.38 20 1371 754 4.0 216 3.24 48.1 20.6 <0.001

Half Assini 1 (SeaWater)

8.38 7.50 64900 35695 <1.00 13886 144 441 1433 <0.001

Rig 4 (south of theRig)

7.33 7.50 64400 35420 <1.00 14680 138 521 1360 <0.001

Rig 3 (East of the Rig)

8.47 7.50 64200 35310 <1.0 12690 142 481 1409 <0.001


8.45 7.50 64800 35640 <1.0 11420 138 481 1409 <0.001

S e a w a t e r –Elembele

8.34 7.50 62000 34100 <1.0 11243 118 441 1215 <0.001

Brackish water –Elembele

8.38 7.50 62300 34265 <1.0 7654 132 521 1336 <0.001

Rig 2 (West of theRig)

8.42 10.0 63100 34705 <1.0 12480 136 441 1239 <0.001

Half Assini 3 (seaWater)

7.30 10 64600 35530 <1.0 13482 152 481 1457 <0.001

WHO GuidelineValue

6.5–8.5

15 - 1,000 - 200 30 200 150 0.001– 1.5

*the bold figures exceeded WHO guideline values.From table 1.1 above, it can be seen that pH of the water samples ranges from 7.33 to 8.47 pHunits. These values falls in line with the WHO acceptable guideline values for pH for marine,brackish and natural resources. High conductivity values were recorded for water samples fromsea water of Half Assini, Elembele and around the rig platform than water samples from riversAnkobra and Asanta or brackish water in the study area. The conductivity values ranges from

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1,371 µS/cm to 64,900 µS/cm. Electrical conductivity which is the ability of water to conductelectric current. The high electrical conductivity values recorded in this study means that there ishigh amount of cations and anions in the water samples.

Total dissolved solids (TDS) concentration in the study area ranged from 754 mg/L to 35,695mg/L. TDS concentrations in most cases were generally higher than 1000 mg/l (WHO, 1993) and(WHO, 2006). Water samples with the highest TDS concentrations were sampled from riverAnkobra, brackish or marine water in Elembele, Axim and Half Assini. High TDS in water mayproduce bad taste, odour and colour, and may also induce unfavourable physiological reactionsin the consumer (Spellman and Drinan, 2000).

Sodium ion concentration ranged from 216 to 14,680 mg/L as shown in table 1.1 above. Sodiumion concentrations in the study areas were generally higher than the WHO guideline limit (200mg/l). Consumption of water high in sodium is believed to increase one’s blood pressure, whichmay lead to cardiovascular diseases (Baird, 1999). High sodium in drinking water may giveunacceptable taste (WHO, 2006).

Total hardness of the water samples from the study area ranged from 240.0 to 7,200 mg/L asshown in table 1.2 below. Water is termed to be soft, moderately hard, hard or very hard if totalhardness range of 0-75 mg/l, 74-150 mg/l, 151-300 mg/l and >300 mg/l respectively are recorded(Lester & Birkett, 1999). Generally water samples from the sea by this classification are hard, aswater samples from the rig area which are marine water samples, brackish water and watersamples from rivers Ankobra and Asanta analysed in the study area respectively, recorded totalhardness concentrations greater than 300 mg/l. Hardness gives an indication of the portability ofwater for drinking and domestic use (washing). A number of ecological and analyticalepidemiological studies have shown a significant inverse relationship between hardness ofdrinking water and cardiovascular diseases (WHO, 2006).

Chloride concentration for water samples in the study area ranged from 315 to 25,212 mg/L asshown in table 1.2 below. Chloride concentration rivers Asanta and Ankobra were found to beabove WHO guideline value (250 mg/L). Chloride level above the WHO guideline limit can giverise to detectable taste to water (WHO, 2006). Chloride concentrations in marine water samplesare generally very high.

Sulphate ion concentration in the study area ranged from 54.1 to 394 mg/L. Generally sulphateion concentration in water samples from the sea water are high, with the exception of one fromElembelle which recorded 57.5 mg/L, well above the WHO guideline of 250 mg/L. The highsulphate concentration recorded may be from the geological formation (Birimian rocks) of thearea or other water bodies which drains into the sea. High levels of sulphate in drinking waterhave been found to cause gastrointestinal effects in human. Nitrate-N levels recorded during thestudy period ranged from 0.01 to 1.10 mg/L as shown in table 1.1 below. Nitrate-N levels in thestudy areas were generally lower than the recommended WHO guideline (10 mg/L). Highnitrate-nitrogen levels in water samples are as a result of run-offs from nearby agricultural lands

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and also due to the unsanitary and unhygienic conditions prevailing around these water bodies.High levels of nitrate ion in drinking water may cause methemoglobinemia in newborn infants,as well as in adults with particular enzyme deficiency (Baird, 1999). Phosphate ion concentrationranged from 0.014 to 0.132 mg/L as shown in table 1.2 below.

Table 1.2 Mean results of physico – chemical parameters in the water samples in the studyareas

Parameters

Sampling Point

Turb/NTU

Cl-/mg/L

SO42-/

mg/LPO4-P/mg/L

NO2-N/mg/L

NO3-N/mg/L

Tot.Hard/mg/L

Tot. Alk/mg/L


1.54 54.1 57.5 0.121 2.48 1.10 240 152

River Ankobra–Axim

1.82 342 342 0.118 0.245 0.415 6,900 124


1.46 20,845 329 0.014 0.026 0.240 6,300 110

Elembele 2 (RiverAsantaDownstream)

2.63 315 329 0.132 0.232 0.513 205 154


4.05 24,517 335 0.024 0.822 0.001 7,000 130


2.20 25,512 335 0.022 0.079 0.400 6,900 138


2.47 16,576 343 0.022 0.457 0.300 7,000 120


2.83 20,943 370 0.029 0.310 0.310 7.000 130

Sea wa te r –Elembele

1.97 19,356 394 0.054 0.352 0.352 6,800 138


2.21 15,286 343 0.090 0.300 0.300 6,100 130


2.12 21,242 360 0.031 0.233 0.250 6,200 124


2.81 23,227 340 0.082 0.274 0.283 7,200 138

WHO GuidelineValue

5 250 250 - 1.0 10 500 -

*the bold figures exceeded WHO guideline values.

The mean levels of heavy metals such as manganese, arsenic, iron, zinc, lead, cadmium, copperand oil/grease concentrations in the water samples from the study area is presented in table 1.3below.

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Table 1.3 Mean levels of manganese, arsenic, iron, copper, cadmium, zinc and oil/grease inthe water samples from the study area.

Concentration in mg/LSampling point

Mn Fe Zn Cd Pb As Cu Oil/grease


0.040 0.772 0.045 0.004 0.005 0.001 0.020 6.0

River Ankobra –Axim 0.051 0.657 0.032 0.092 0.414 0.001 0.065 12


0.048 0.443 0.091 0.105 0.286 0.001 0.059 44

Elembele 2 (RiverAsanta Downstream)

0.087 0.754 0.007 0.101 0.005 0.001 0.078 18


0.059 0.684 0.048 0.096 0.184 0.001 0.070 10


0.058 0.690 0.047 0.101 0.259 0.001 0.053 15


0.049 0.539 0.048 0.100 0.471 0.001 0.065 41


0.054 0.563 0.048 0.089 0.216 0.001 0.020 28

Sea water – Elembele 0.521 1.15 0.057 0.002 0.372 0.001 0.059 40


0.059 0.754 0.011 0.004 0.477 0.001 0.034 8.0


0.049 0.435 0.034 0.092 0.312 0.001 0.072 40


0.063 0.908 0.080 0.116 0.310 0.001 0.073 44

WHO Guide l ineValue

0.4 0.3 3.0 0.05 0.015 0.01 2.0 -

GEPA Guidel inevalue

- - 10 - - 1.0 - 10

*the bold figures exceeded either WHO or GEPA permissible guideline values.

From table 1.3 above, it can be seen that the concentration of manganese ranged from 0.040 to0.087 mg/L. Manganese is a neurotoxin and as such exposure to elevated levels of it via oralingestion poses significant health hazard. Manganese concentration in the water samples in thestudy area were found to be below the WHO permissible value of 0.40 mg/L.

Total iron concentration in the study area ranged from 0.435 to 1.15 mg/L . The prevalence ofiron levels above 0.3 mg/l was noticeable in all the water samples collected from the study area.The presence of high iron could be as a result of chemical weathering of the host granitic and

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metamorphosed rocks, which could have resulted in the dissolution of iron that ultimately,percolate through the overburden to enrich the groundwater in storage (Darko, 2006). Runoffs ofwater samples from the mining areas in Tarkwa, Prestea, Telezu Bukazo, etc into river Ankobrawhich drains into the sea at Axim could also account for the elevated levels of iron.

Lead ranged from 0.005 to 0.477 mg/L as shown in table 1.3 above. High concentration indrinking water may lead to damage of the brain, red blood cells and kidneys. Generally theconcentration of lead in most cases exceeded the WHO permissible guideline values of 0.015mg/L.

Arsenic ion levels in all the water samples were 0.001 mg/L as shown in table 1.3 above. Thissuggests that arsenic contamination as result of oil and gas exploration in the study area is veryminimal. However, it is important to note that exposure to As at high concentrations posesserious health effects as it is a known human carcinogen. It has also been reported to affect thevascular system in humans and has been associated with development of diabetes.

Cadmium ion levels in all the water samples collected for this study ranged from 0.004 to 0.105mg/L as shown in table 1.3 above. The cadmium concentrations in some cases were found to beabove the WHO acceptable value of 0.05 mg/L. Exposure to elevated levels of cadmium posessignificant health hazard to both aquatic organisms and human beings who consume suchorganisms.

Oil and grease content in the samples were used as a measure of oil pollution from oil and gasexploration activities being undertaken by Jubilee partners. The concentration of oil/grease in thewater samples ranges from 6.0 to 44 mg/L as shown in table 1.3 above. The highest oil/greaseconcentrations were found from water samples around the Jubilee rig platform which was foundto exceed the Ghana Environmental Protection Agency (GEPA) permissible guideline value of10.0 mg/L. This suggests that activities of the Jubilee partners are gradually polluting marinewater and other water bodies which have serious implications for marine organism and humanbeings.

CHAPTER FIVE

CONCLUSION AND RECOMMENDATION

5.0 Conclusion

This study investigated the effects of oil and gas exploration and extraction by the Jubilee OilField partners on water marine waters and other water bodies in Nzema East Municipality,Jomoro District Assembly and Elembelle Municipality.

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The results of the study revealed the following:1. Elevated levels of lead, manganese, cadmium found in marine water samples around the

Jubilee Rig is an indication of the discharged of low toxicity oil based mud and other drillcuttings which contains these toxic chemicals.

2. The discharge of these fluids is also affecting water quality.3. The presence of elevated levels of oil and grease in the water samples is an indication of

oil pollution from the operations of the Jubilee Field.

5.1 Recommendation

From the results of the study, the following is recommended:1. Government should ensure that domestic regulations and relevant international standards

are rigidly enforced to protect and safeguard our marine environment.2. CSOs should advocate for government to pass legislation on the ‘polluter pay principle’.3. CSOs should advocate that government expedite that action on the passage into laws of

all pending bills in the oil and gas industry.4. Government should ensure that relevant environmental conventions ratified by Ghana are

incorporated into domestic laws.5. A further research should be conducted to isolate, characterize and determine the

concentrations of polycyclic aromatic hydrocarbons in water, sediment and aquaticorganisms in the study area.

REFERENCE

• Akosua k darkwah,2010. The impact of oil and gas discovery and exploration oncommunities with emphasis on women.

• www.itof.com/effect/html. “Effect of marine oil spills, December 2006”

• U.S. Energy Information Administration (USEIA, 1997): Nigeria’s country analysisbrief. December 1997

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• Patin, S. A. (1999): Environmental impact of the offshore oil and gas industry. Stanislavaleksandrovich. I999. PhD Thesis Submitted to the University of Leeds. Retrieved fromwww.ideas connection.com/so/1404.environmental impact.oil extraction.html.

• U.S. National Academy of Sciences: Oil in the sea III: Inputs, fates and effects. Report2002 by the National Research Council (NRC) Committee on Oil in the Sea: Inputs,Fates, and Effects.

• United Nations Environmental Programme (2009) ‘From Conflict to Peace building; TheRole of Natural Resources and Environment’ UNEP.

• United Nations Conference on Trade and Development (2007) ‘Globalization forDevelopment: Opportunities and Challenges’ Report of the Secretary-General ofUNCTAD to UNCTAD XII, Geneva, United Nations.

• Legborsi Saro Pyagbara. 2007. The Adverse Impacts of Oil Pollution on the Environmentand Wellbeing of a Local Indigenous Community: The Experience of the Ogoni Peopleof Nigeria. United Nations publication.

• Odiete WO (1999). Environmental physiology of animals and pollution. DiversifiedResources Ltd.,

• American Petroleum Institute (1978). API Recommended Practice. Standard Procedurefor Testing Drilling Mud, API, Washington D.C. pp. 35.

• Arscott RW (1993). New directions in environmental protection in oil and gas operations.Petroleum Technology, Texas pp. 193

• Darley HCH (1988). Composition and properties of drilling and completion fluids. Gulfpublishing company, Houston, Texas p. 665

• Valkonic V (1978). Trace Elements in Petroleum. Petroleum Publishing Company, Tulsa.p. 122

• Imevbore AMA (1979). Impact of oil production on five biota of the Niger delta, lectureseries 10. University of Ife Press, Nigeria.

• Reis JC (1988). Environmental control in Petroleum Engineering, Gulf PublishingCompany, Houston, Texas, pp. 560.

• Richard JG (1993). The Environment of Oil, Kluwer, Academic Publishers, USA. p. 307.

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