Quality water not everywhere: Exploratory Analysis of Water Quality Across Ebocha-Obrikom Oil and Gas Flaring Area in the Core Niger Delta Region of Nigeria

Groundwater (GW) quality is crucial for indigenous population of Nigeria’s oil rich communities, their health, food system, societal stability and welfare. This study aims to compare water quality parameters with the recommended standards in the study areas. Result depicts that geogenic enrichment of harmful elements like Turbidity, DO, BOD, COD, TSS, Magnesium, Iron, Cadmium, Lead, Chromium, and Nickel etc. exceeded the desirable limit aimed at drinking purpose as well as would likely threaten human society, including safe utilization and rational management of groundwater resources. Thus, remain unsuitable for drinking. These potential toxic elements should be paid attention to when the water is utilized as a domestic water resource.


Introduction
In Niger Delta, the availability and drinking water quality remain a re ection of where you reside. Due to its perceived abundance, it has mainly been taken for granted particularly its access and safe drinking  . Besides, advisories remain mostly given as a preventative measure, not necessarily on the basis that water is dangerous or unsafe or the risk is consistent; therefore, the degree of the drinking water risk differs on a case-to-case basis . In spite of these, when drinking water availability or quality is undermined, trustworthy as well as e cient public/environmental health sector risk communication is important to reduce negative health impacts, Generally, rural and small communities (Indigenous population or not) across the Niger Delta region have their own particular sets of drinking water issues, for example: whether local access to water quality monitoring expertise is available (Raimi et  More particular, researchers discovered that the indigenous population in oil rich communities, has insu cient record keeping, which included factors like the past improvement, the various infrastructure age within the system, as well as [when or why] past water advisories [have occurred], which led to knowledge gaps in the supplies of water as well as distribution systems. The ability toward accessing safe as well as clean drinking water along shorelines of the Niger Delta is further compounded via the geographical and climatic properties of these regions (Raimi et  ). This will also assist ground water managers as well as policy makers assess the health consequences associated with their own actions, thus this will give policy makers a basis of making sound policy on whether they should base on environmentally friendly development to boost groundwater quality or focus on economic growth alone and would permit aid organizations toward targeting their resources more e ciently (Raimi et  large. Consequently, this study aimed to compare water quality parameters in the vicinity of Gas Flaring Area of Ebocha-Obrikom of Rivers State with that of the recommended standards. Thus, this research may provide valuable information on the heavy metals and other physico-chemical analysis of drinking water associated with the contamination of the ground waters by petroleum products.

Material And Methods
The Study Area The area is placed between latitude 5 0 20N -5 0 27N and longitude 6 0 40E -6 0 46E is situated in Ebocha-Obrikom ( Figure 1). It encompasses Obrikom, Obie, Obor, Ebocha as well as Agip New Base towns all located in Ogba/ Egbema/Ndoni Area of Rivers State ( Figure 1). The study research area lies to the North by River Nkissa, by the West, River Orashi, by the East, River Sombrero and by the South Omoku town.

Climate
The climate of the study area is the equatorial type. Heavy rainfall of about 2500 mm/annum are experienced in the region. During the year, the rainfall takes around eight (8)

Topography and Drainage
The area is actually drained by the Sombreiro on the Eastern anks and Orashi on the Western ank creating an almost uninterrupted inter-basinal area. The region has a topographic structure virtually at, as well as is covered by super cial soil, which is made up of silty clays combined with silty sand. There is a clear lack of imposing hills that rise above the whole land surface at a height of about 25 metres above sea level.
The Orashi River is a prominent feature of the natural drainage system. This river, although an independent river system, which accounts for the drainage of the entire zone, links up with the Niger Delta system during the wet season ( ood stage). Due to the more prominent relief of this area, drainage is more e cient and much fewer rivers and creeks drain the area. Backswamp depressions exist which entrap oodwaters and so form perennial lakes in the area. The rivers are prone to ooding which increases the level of water in the water table. The rivers found in the study area are also subjected to tidal ow ( (see  table 2 below), extracted water samples from groundwater sources utilized mostly for drinking as well as domestic activities. Sample collections were limited to only groundwater from dug wells or shallow pumping wells built for household uses exclusively. The depth of the wells varies between 10 to 28m, which is a phreatic aquifer. The sampling locations sites were documented using portable GPS devices.
In the vicinity of the depot, ground water sources were selected randomly but at various distances from each other for the purpose of this investigation. Furthermore, the samples were manually collected from nine (9) strategic locations in the study area for ground water (boreholes and wells) into previously washed clean plastic sampling bottles after about 20 min of continuous water ow to ensure adequate aquifer quality that can be appropriately represented. All of the samples was obtained during the daytime, from 9.00am to 4.00pm. Due of insecurity, ooding and COVID-19 lockdown. Night samples were not collected and sampling was performed between September, 2019 to August 2020.

Sampling, Preservation and Analysis
The standard methods outlined in APHA (2012); Morufu and Clinton (2017); Raimi and Sabinus (2017); Olalekan et al. (2018) have been followed by water sampling, conservation, transportation as well as analysis.

Ground Water Collection
For the analyses of physico-chemical parameters, ground water samples were collected using pre-rinsed 1litre plastic containers. Pre-rinsed ground water samples for heavy metal analyses were collected with nitric acid of 1litre containers as well as treated with 2ml nitric acid (assaying 100%, Trace Metal Grade, Fisher Scienti c) prior to storage. These were done to stabilize the metals oxidation conditions. Groundwater samples were collected in two groups of 250ml glass-stoppered-reagent bottles per sampling location for Biological Oxygen Demand (BOD), and Dissolved Oxygen (DO) determinations. The BOD samples have been properly lled without air trapping as well as the bottles covered in black polythene bags. This was done to eliminate light, which is present in the samples and capable of producing DO by autotrophes (algae). The BOD samples were incubated for ve days, which was added to 2ml of each sample. In order to retard additional biological activities, Winkler solutions I and II use different dropping pipettes to each sample. The bottles were thoroughly shaken to precipitate the oc, which lay at the bottom of the bottles. Further, Winkler solution I is a solution of manganese sulphate, while solution II is sodium or potassium iodide, sodium or potassium hydroxide, sodium azide (sodium nitride) and sodium hydroxide. The DO samples were collected in clear bottles and also tightly stoppered. With samples of dissolved oxygen preserved on the spot with Winkler I and II solutions similar to that of the BOD samples (APHA, 2012). All samples had been clearly identi ed and controlled at 4°C for easy identi cation. Determination was carried out on site to know the concentrations of unstable as well as sensitive water quality characteristics including total dissolved solids (TDS), electrical conductivity (EC), pH, alkalinity (Alka.), and temperature (Temp). Thus, the fundamental approaches for investigating the groundwater composition are described in gure 2 below.
Quality assurance and quality control (QA/QC) Additionally, employing high purity analytical reagents as well as solvents, all analytical procedures were closely monitored with quality assurance as well as control techniques. Calibration standards were applied to the instruments. Procedure blanks, triplicate analysis as well as the analysis of certi ed reference materials (CRM) was performed through the analytical technique validation. For every organic pollutant from the groundwater samples, the limit of detection (LoD), repeatability, reproducibility, precision, as well as accuracy was established.

Results
Compare water quality parameters in the study areas with that of the recommended standards.   quality parameters obtained during dry season were above the standards as provided in Table 4.

Discussion
Compare water quality parameters in the study areas with that of the recommended standards.
[Groundwater Suitability for Drinking and Irrigation] It is essential to determine the appropriateness of the groundwater resources in a researched area, since it is an essential element. Tables 3 and 4    . The pH is remarkably vital for understanding water nature, as well as likewise make evident a tight proximity with other water chemical components. The value of pH in drinking water is a signi cant index of alkalinity, acidity and resulting value of acid base interaction of its minerals and organic components. Measurement of pH is one of the most essential recurrently used water chemistry test. Although the pH is not directly affecting human health, it is one of the utmost signi cant parameters for water quality. A suitable pH range of 6.5 to 8.5 is generally adopted, according to the WHO recommendation. pH values observed in the range of 6.57 to 6.59 in the water samples were found in this study. This demonstrates that pH was perceived to be slightly demonstrating naturally acidic. From the groundwater results, the pH of the water samples fell within the recommended standards as provided by WHO, SON and NAFDAC during wet and dry season. In any of the groundwater testing, however, both seasons were found to remain within the maximum allowed limit. As a result, based on pH as an indication of agriculture and population, the groundwater seems not to appear to be a serious pollution threat to the milieu. Thus, the pH water value of the test zone is clearly below the allowed limit (6.5-8.5). There is no misunderstanding, therefore, that the region is neither overly acidic or alkaline. Turbidity denotes the relative purity of the water which hinders light transmission and is triggered by chemicals that do not occur in true solution form as well as is directly connected to light dispersal. The ground water turbidity in the research area shows higher turbidity during rainy season (17.57mg/L) representing higher rate of light scattering affecting photosynthesis. Thus, higher turbidities could be due to continuous and impactful predisposition to receiving large quantities of organic and inorganic materials emanating from gas aring and oil spillage contaminating the ground waters of the study area. Thus, the maximum turbidity level surpassed the WHO/NAFDAC/SON drinking water quality recommendations. It is therefore doubtful that it will be appropriate for drinking. As numerous previous studies have revealed that the turbidity in Ebocha-Obrikom groundwater area is signi cantly more than the permissible levels of the WHO/NAFDAC. Likewise, dissolved oxygen (DO) is the oxygen gas (O 2 ) that is dissolved in water and it is a highly signi cant water indicator/constituents which affect physiological and biological process and for its quality as well as help to maintain biological life in aquatic ecosystem. For excellent water quality, enough dissolved oxygen is required. All kinds of life are made out of oxygen. Oxygen in uences a large range of other water indicators, such as the odour, clarity as well as taste not only biochemical, but also aesthetic ones. Oxygen removes from the water through aquatic living things respiration as well as organic matter decomposition. A higher metabolic activity as well as inorganic reducing agents like NH 3  during the dry season (33.27)mg/L. All values recorded in this study were above the recommended maximum permissible limit. Generally, it could be deduced that seasons affected TSS more than the level of anthropogenic activities within the study area. This is because increased atmospheric precipitation during raining seasons help increases the amount of materials in ground waters unlike during the dry seasons where reduced precipitation help in removing suspended particles in groundwater. Also, excessive in ux of suspended solids during the raining season could be attributed to discharge of large quantities of substances directly into surface water bodies or out rightly onto terrestrial regions from where they percolate into ground water bodies. This could be owing to the fact that gas aring releases . While, iron in groundwater causes a "rusty" taste in water. It not only gives an unpleasant taste; it can also stain pipes as well as clothing. Iron is natural in nature, and it is the fourth rich earth element in ground water of the research area occurring cosmopolitically, and thus most groundwater has a certain quantity of iron in it. Iron is derived from the earth minerals, like shale, limestone, as well as coal. In this study, the concentration of iron content for raining seasons ranges from 0.95 to 7.3 mg/L with a mean of 2.95 mg/L, and for dry seasons, Fe ranges from 0.56 to 6.35 mg/L with a mean of 2.43 mg/L, Fe concentration exceeds the allowable drinking purpose limit. While iron de ciency causes hemoglobin as well as cytochromes to decreases, excess of it causes tissues damage through iron accumulation. Hence, iron was found exceeding maximum permissible recommended limits provided by WHO, SON and NAFDAC. It is evident in general, the Ebocha-Obrikom ground water bodies contain higher amounts of iron as well as make the water inappropriate in a range of domestic/ residential purposes. Many treatment options are available, among them, water softener installation. In iron precipitation, aeration, oxygen addition to the water can also help to eliminate it from the water.
Besides, Iron was also the second richest metal on the earth's crust in the world (USEPA, 2017 The dissolved iron concentration is typically 0.6 nM or 33.5 × 10 -9 mg/L in deep ocean, as well as in freshwater, the detection level concentration is extremely low with 5μg/L -ICP, however in groundwater, the dissolved iron concentration is rather high with 20 mg/L (USEPA, 2017). Several people in the Niger Delta region of Nigeria were exposed to higher concentrations of iron by means of drinking water, as the groundwater collected exceeded the WHO/SON/NAFDAC acceptable limit for drinking water quality ; Afolabi and Raimi, 2021). The species abundance, including benthic invertebrates, periphyton as well as sh diversity are severely in uenced by the direct as well as indirect iron contamination effects (Vuori, 1995). The precipitate iron will cause signi cant harm through clogging action as well as hinder shes' respiration (USEPA, 2017). Lead (Pb), and cadmium (Cd) are highly toxic metals that have no known physiological role but can cause adverse health effects even at trace levels.
The higher risk of high blood pressure (hypertension) as well as cardiovascular disease (CVD) in adults is associated to exposure to certain metals ( . The prevalence of exposure to these metals among pregnant women is high. The general resident of Ebocha-Obrikom is ubiquitously exposed to toxic metal such as cadmium through the diet and gas aring as the main sources. Cadmium exposure is associated with increased morbidity and mortality in myocardial infarction and stroke. Atherosclerosis is the main underlying mechanism of myocardial infarction. However, associations between cadmium and coronary artery atherosclerosis have not been examined. Cadmium accumulates mainly in the kidneys and has a half-life of decades, and therefore it usually increases with age. Exposure and body burden can be assessed by measuring blood or urine cadmium concentrations (Nordberg et al., 2015;Akerstrom et al., 2013). Apart from being a well-known cause of kidney and skeletal damage, blood or urine, cadmium has been reported to be an independent cardiovascular disease risk factor, together with coronary heart disease in several reviews (Tellez-Plaza et al. nally cause fragile bones, kidney disease, as well as lung damage (Bernard, 2008). In comparison to other metals, cadmium and its derivatives are extremely water soluble. Because of their high bioavailability, they tend to bioaccumulate in the body. Long-term cadmium exposure can cause morphopathological abnormalities in the kidneys. Cadmium poisoning is more common in smokers than in nonsmokers. Tobacco plants, like other plants, may acquire cadmium from the soil, making it the principal source of cadmium intake in smokers. Cadmium is ingested by non-smokers through gas aring, food as well as some other sources. However, cadmium uptake via other routes is signi cantly Kumar-Patra, 2013). Oil as well as coal burning, petroleum from ferro chromate refractory material, catalyst, pigment oxidants, fertilizers, chromium steel, oil well drilling as well as metal plating tanneries are all-natural sources of chromium. Chromium is discharged into the milieu anthropogenically through sewage as well as fertilizers (Ghani, 2011). Cr(III) is immobile and insoluble in water in its reduced form, but Cr(VI) is extremely soluble in water as well as consequently mobile in its oxidized state (Wolińska et al., 2013). Speciation of metal is critical for determining the metal ions activities in the milieu, as the oxidative form of Cr(III) is not a crucial ground water contaminant in the case of chromium, but Cr(VI) has been recognized to be toxic for humans. Cr(III) resides in the organic matter of soil as well as aquatic environment in oxides form, hydroxides as well as sulphates (Cervantes et al., 2001;Cervantes et al., 2017;. Chromium is widely utilized in industries like tanning, electroplating, metallurgy, production of paints and pigments, chemical and petroleum production, wood preservation, pulp as well as production of paper. These industries contribute signi cantly to chromium pollution, which has a negative impact for biological as well as ecological species (Ghani, 2011;Olalekan et al., 2021). Chromium pollution is a concern due to a variety of industrial as well as agricultural practices that raise the harmful levels in the milieu. In recent years, chromium pollution of the milieu, mostly hexavalent chromium, has become a major concern (Zayed & average of 0.1 mg/l. Both ammonia as well as phosphate levels were higher than the WHO limit but lower than the SON guidelines. As a result, they did not pose a hazard to groundwater quality in terms of the SON criterion (Table 3  reproductive, genotoxicity, neurologic, immunotoxicity, haematotoxicity and developmental effects. The utmost poisonous nickel compound is nickel carbonyl. Hence, the majority of con ned groundwater in the research area is therefore fresh as well as soft, implying desirable quality water aimed at human community utilization in terms of the major solute chemistry. While con ned groundwater quality by the anthropogenic factors was not affected, the natural hazardous elements together with turbidity, TSS, BOD, DO, COD, Cadmium, Magnesium, Iron, Chromium, Lead as well as Nickel exceeded the required drinking purpose limit as well as would hypothetically threaten the human society. Hence, when water is utilized as a domestic water resource, these potential toxic elements should be paid attention to. So far, not all con ned groundwater in the study area pose a health risk to humans, emphasis must remain concentratedly focused on the places where the toxic elements pose a potential threat. In general, the quality of groundwater in this area is quite low as well as not appropriate for drinking. For the quality of groundwater in these locations, the high concentrations of the above-mentioned criteria are accountable. Thus, poor quality groundwater will therefore affect the health of indigenous residents who utilize untreated groundwater for cooking, drinking or other household uses will remain impacted. The primary human health impacts of pollutants are shown diagrammatically as follows (see gure 3 below).
Hence, there is need for the oil and gas company to support groundwater exploitation management in the study area and to fully implement centralized supply of water in Ebocha-Obrikom areas of Rivers State, as well as encourage indigenous residents to decrease their usage of untreated groundwater to guarantee residents' safety of drinking water.

Conclusion And Implications
The comprehensive yearly industrial chemicals production has doubled to almost 2.3 billion tonnes since the turn of the 21 st century, and is expected to rise by 85% come 2030. As a result, environmental and water contamination are likely to worsen unless there is a swift shift in consumption and production habits, as well as a political commitment to true sustainable water management that completely respects nature. The environmental pressure has increased as a result of the recent global pandemic scenario created by COVID-19, which has intensi ed waste release. In the Ebocha-Obrikom oil and gas producing area of River State, Nigeria, an integrated approach was used to successfully establish and identify overall suitability assessment of groundwaters for both drinking as well as domestic purposes. Since, groundwater in Ebocha-Obrikom is an important natural resource that is mostly used for domestic as well as agricultural purposes. Overall, a higher percentage of the groundwaters examined are unsuitable for drinking as well as domestic use. Because the quality of water suitability is tied to the water ingested or consumed. So as to produce consistent outcomes aimed at decision making in the face of uncertainty surrounding groundwater threat. the water quality within the research area has been determined to be impaired owing to high levels of physico-chemical and heavy metals parameters (for example Turbidity, DO, BOD, COD, TSS, Magnesium, Iron, Cadmium, Lead, Chromium, Nickel etc.); hence, these poor drinking water quality parameters remain seen as a core in uencer. The following highlights are offered after the overall research ndings: Physicochemical analysis thus revealed that some of physicochemical parameter's remain within recommended standards, notwithstanding most of the water samples having concentrations of Turbidity, DO, BOD, COD, Alkalinity, TSS, Magnesium, Iron, Cadmium, Lead, Chromium, Ammonia, Phosphate, Nitrite and Nickel etc. remain above the recommended standard, describing such waters as un t for drinking and domestic purposes.
As a result, under current market economy circumstances, the pollution problem is unlikely to be resolved spontaneously. it is vital that policy instruments should remain used in controlling pollution from this point forward. Thus, it is imperative to identify the environmental policy instruments aimed at improving people's welfare while taking into account the capabilities of relevant stakeholders and putting in place a systematic manner.
Human interference (indiscriminate discharge of drainage wastes as well as unregulated use of industrial and agricultural chemicals) must remain more effectively as well as strictly managed, as this is the utmost signi cant approach for preventing groundwater pollution.
It is critical to establish a frequent groundwater quality monitoring network in order to understand the causes as well as sources of groundwater contamination on a regular basis so that appropriate remedial actions may be taken in a timely manner.
Improving groundwater quality monitoring network is advised by creating and raising public awareness (through television, radio, print media and internet). Thus, these strategic measures help decision makers in the development as well as management of groundwater resources in a sustainable manner.
The obligation for implementing adequate management measures toward improving the quality of groundwater must be assumed on the civic authorities.
Other Niger Delta States experiencing similar di culties will bene t from the study's recommendations.
Mcfubara, Prof. B.E. Akpan, Prof. I.M. Aprioku as well as all anonymous reviewers, for feedback and discussions that helped to substantially improve this manuscript.
Funding: The water sampling and analysis was supported by AGIP Research Department.
Con ict of Interest: The authors declare that no commercial or nancial relationships existed that could be construed as a potential con ict of interest when conducting the research.  Figure 2 A schematic illustration of quanti cation methodology adopted for the current study. Main effects of contaminants on human health, indicating the organs or systems affected and the contaminants causing them. Source: Adapted from FAO and UNEP (2021)