HYDROGEOCHEMICAL CHARACTERIZATION AND PUBLIC HEALTH RISK ASSESSMENT OF SHALLOW AQUIFERS IN THE FLOOD-PRONE ODI COMMUNITY, NIGER DELTA

www.ijprems.com [email protected] INTERNATIONAL JOURNAL OF PROGRESSIVE RESEARCH IN ENGINEERING MANAGEMENT AND SCIENCE (IJPREMS) (Int Peer Reviewed Journal) Vol. 05, Issue 12, December 2025, pp : 427-435 e-ISSN : 2583-1062 Impact Factor : 7.001 @International Journal Of Progressive Research In Engineering Management And Science 427 HYDROGEOCHEMICAL CHARACTERIZATION AND PUBLIC HEALTH RISK ASSESSMENT OF SHALLOW AQUIFERS IN THE FLOOD-PRONE ODI COMMUNITY, NIGER DELTA Ovuru Cyril1, Diepiriye Chenaboso Okujagu2, Amgbare Peace Ebikomboere3 1,3Department Of Geology, Niger Delta University, Wilberforce Island, Bayelsa State, Nigeria. 2University Of Port Harcourt, Port Harcourt, Nigeria. E-Mail: diepiriye.ok[email protected].ng ABSTRACT Groundwater as an alternative to the polluted surface water system is a growing dependence in the Niger Delta; however, there is continuous threat to its quality by geogenic and anthropogenic activities. The work is aimed at providing an extensive hydrogeochemical characterization and human risk assessment of groundwater in Odi Community, Bayelsa State which suffers seasonal flooding and low water tables. Therefore, The main intent was to assess the potability of the local aquifer and determine risks to health associated with consumption of heavy metal. Seven productive boreholes were sampled and analyzed via a comprehensive suite of physicochemical parameters, admit pH, temperature, turbidity, Total Dissolved Solids (TDS), Biochemical Oxygen Demand (BOD), Dissolved Oxygen (DO), and major ions (Na, Mg, Ca, Cl, SO₄, Fe). As a result, the Analytical procedures conformed to standard APHA procedures, and the findings were strictly compared to the World Health Organization (WHO) standards. However, The assessment released a ground water profile with a slight acidity (pH 6.6516.79) and exceedingly high turbidity (8.4618.2 NTU) with all positions exceeding the WHO allowable level at 5 NTU. However, While Total Dissolved Solids (386102 mg/L) and Electrical Conductivity (852027) parameters were positive indicators of fresh and low- -mineralize water, biochemical parametric value was upsurging business; BOD levels peaked up to 9.5 mg/L, which is indicative of high organic contamination due to percolation of surface runoff or weak grouting of borehole. It is based on a statistical analysis, a Pearson Correlation Matrix, that confirmed that turbidity and the microbial indicant have a strong positive correlation, which confirms the theory of surface - to - aquifer contamination pathways. Despite the fact that heavy metal concentrations of Iron (Fe) were mostly within aesthetic range (0.06510.23 mg/L), the levels of Sodium (Na) were a bit higher than the regulatory deadlock in certain areas. Probabilistic Human Health Risk Assessment (HHRA) was done with a calculation of Hazard Quotient (HQ) of non - carcinogenic risks. Even though the 'HQ economic value of individual metallic elements was less than unity (< 1) which is an indicator of no quick chronic terror, the cumulative contamination index report that the water should be discussed; that is, pH correction, coagulation, and disinfection should be done before it is ingested. Contrastingly, This cogitation throws light on the susceptibility of the Benin Formation aquifers to seasonal changes in the environment and the need to continuously monitor the hydro to ensure citizens remain healthy. Keywords: Hydrogeochemistry, Water Quality Index (WQI), Human Health Risk Assessment, Groundwater Pollution, Niger Delta, Environmental Health. 1. INTRODUCTION Water is the rudimentary currency of biological world and a decisive driver of socioeconomic maturation (Bruinsma, 2003). In sub - Saharan Africa, the search for drinkable water continues to represent the fix of the 21st century (Adelana & MacDonald, 2008). While the Niger Delta region of Nigeria has the paradox of being blessed with copious freshwater resources owing to a high pitch of precipitation and an obtuse network of river organisation, the accessibility of safe drinking water is severely marred (Nwankwoala & Ngah, 2014). The area faces a “water wealth, water poverty'' dichotomy where airfoil piss are frequently polluted by hydrocarbon exploration activities (Amosu & Adeosun, 2021), industrial effluents (Ntengwe, 2006), and poor sanitation practices, force the population to rely heavily on groundwater. This is the case of why ground water is normally selected since it is naturally shielded or enclosed by the top layer of soil which serves as a filter in blocking the suspended particles. This is a natural form of defense which most of the time is violated in the Niger Delta. The underlying formation is Aquifer System which are in this region very good transmission and high porosity (Offodile, 2002). These geologic characteristics are responsible not only in causing some of the high water to move out, but also cause the default contaminants to move out of the surface to the water table very fast. Such vulnerability is increased in a place like Odi where there is low water table and topography is slightly inundated by the River Nun on a seasonal basis. www.ijprems.com [email protected] INTERNATIONAL JOURNAL OF PROGRESSIVE RESEARCH IN ENGINEERING MANAGEMENT AND SCIENCE (IJPREMS) (Int Peer Reviewed Journal) Vol. 05, Issue 12, December 2025, pp : 427-435 e-ISSN : 2583-1062 Impact Factor : 7.001 @International Journal Of Progressive Research In Engineering Management And Science 428 The general hydrogeological studies conducted on the Niger delta recorded earlier have recorded issues like high pitch iron density, acidic PH, as well as microbial contamination (Etu-Efeotor, 1981; Udom et al., 2002; Olobaniyi & Owoyemi, 2006). Nonetheless, there still remains a critical research gap reckon the actual hydrogeochemical development of groundwater in flood - prone riverine community of interests such as Odi (Oki & Akana, 2016). The prevailing literature focuses on oil - pressed regions, and this too should not omit communities where the leading menace is manifested through silent forms of stressors like seasonal flooding caused by leaching, agricultural runoff and mineral dissolution induced by geogenic processes. Also, there is not much work in the specified area that has not only focused on the concentration itself but also applied quantitative Human Health Risk Assessment (HHRA) models. Knowledge of not merely presence of chemicals, but probable biological wallop of the population, is essential to evidence - found policy making (Jakeman et al., 2016). Consequently, The particular basic interaction between the seasonal flood regime and unconfined aquifers in Odi constitutes a particular hydrogeological scenario. During the wet season, increase of hydraulic head at the adjacent rivers reverses groundwater flow rate direction or raises the water table to contaminate septic soakaways and Earth's surface contaminant (Ngah & Nwankwoala, 2013). This study therefore, aims to bridge the existing knowledge gap by providing a detailed hydrogeochemical characterization of Odi aquifer. Beyond the usual physicochemical psychoanalysis, this research involve the use of statistical correlation matrices and risk assessment models (Hazard Quotients) to assess the suitability of water for human consumption. The finding are intended to assist as a baseline for environmental monitoring and informing the design of appropriate water system intervention interventions for the community. 2. STUDY AREA AND GEOLOGY 2.1 Geographical Setting and Climate The study area, Odi, is an old and populous community located in a Local Government Area, Kolokuma / Opokuma Bayelsa State. Geographically, it falls in the coordinates which are typical of the central part of the Niger Delta, flanked by the wander channels of the River Nun. The region has a humid tropic equatorial mood (according to the Koppen climate classification, Af), determined by two well defined and different seasons: a long and bright wet period of time, which generally lasts from March to November, and a period of short and ironic season, from December to February. Consequently, Annual rainfall in this zone is precipitous which is around 4,000 mm / year on average (Enete & Ezenwanji, 2011). This mellow volume of hastiness is the primary source of recharge for the local aquifers. Nevertheless, yet, it as well leads to the phenomenon of “seasonal flooding, '' where the River Nun overrun its bank, inundating the low - dwell plains. Ambient temperatures remain consistently high, ranging between 25 ° C and 32 ° C, which promotes rapid chemical weathering of the surface soil and accelerate bacterial proliferation in open waters. Figure 1: Map of the Study Area showing the drainage network of the River Nun and sampling points BH1–BH7 2.2 Geological and Hydrogeological Framework The geological framework of Odi is an built-in part of the Cenozoic Niger Delta basin, which is composed of three major lithostratigraphic units: the Akata, Agbada, and Benin Formations (Reyment, 1965). www.ijprems.com [email protected] INTERNATIONAL JOURNAL OF PROGRESSIVE RESEARCH IN ENGINEERING MANAGEMENT AND SCIENCE (IJPREMS) (Int Peer Reviewed Journal) Vol. 05, Issue 12, December 2025, pp : 427-435 e-ISSN : 2583-1062 Impact Factor : 7.001 @International Journal Of Progressive Research In Engineering Management And Science 429 The Benin Formation: This is the uppermost unit and the primary aquiferous layer in the study area. It consists of continental sediment of massive, highly holey, freshwater - brook sands and crushed rock, with minor intercalations of shale and clay. The littoral zone are typically medium - to - coarse grained, sub - angular to sub - rounded, and ill sorted. Hydrogeology: The high permeability of the Benin Formation sands allows for rapid groundwater reload but extend little retardation to contaminant transport. In addition, In Odi, the aquifer is largely unconfined to semi - confined. Therefore, The water supply table is extremely high, often less than 3 to 5 meters below ground level during the dry season and ascend to nearsurface levels during the wet season (Ngah & Nwankwoala, 2013). Moreover, This shallow depth throw the groundwater intimately connected to surface conditions, rendering it highly sensitive to anthropogenetic activities such as waste disposal and agricultural practices (Ugbaja & Edet, 2004). 3. MATERIALS AND METHODS 3.1 Sampling Strategy and Collection A predesigned cross-sectional study was conducted in the community to obtain a representative hydrochemistry profile. Seven operational boreholes (BH1-BH7) were selected for monitoring. The choice standpoints were the following: geographical distribution, distance to pollution sources (septic tanks and landfill), and population uses. Water samples were collected in clean, 1 .0-liter polyethylene terephthalate (PET) bottles. A harsh decontamination protocol was observed to prevent cross contamination. Bottles were clean with nonionic detergent, rinsed with distilled water, and soaked in 10% nitric acerbic (H N O3) overnight. At the sampling sites, the boreholes were pumped for 5–10 minutes prior to collection. This purging process is essential to remove dead water from the casing and storage tanks, ensuring the sample represents the in-situ aquifer water. The bottles were rinsed three times with the sample water before the last collection. 3.2 Preservation and Laboratory Analysis Preservation methods adhered to the Standard Methods for the Examination of Water and Wastewater (APHA, 2012). Physicochemical Samples: Samples destined for gross analysis (pH, Turbidity, Anions) were filled to the brim to eliminate headspace and stored at 4°C. Heavy Metal Samples: Samples for metal analysis (Fe, Cu, Na, Ca, Mg) were filtered and instantly acidified in situ to pH < 2 using concentrated analytical grade azotic acid (H N O3). This acidification step is serious to prevent the precipitation of metals and their adsorption onto the container walls. BOD Samples: Collected in grim glass bottles to inhibit photosynthesis and incubated instantly upon arrival at the laboratory. 3.3 Analytical Techniques In the laboratory, precision and accuracy were evaluated through the use of calibrated instruments. pH and Temperature: A digital conductivity meter was used for the measurement. Turbidity: The analysis was done with a nephelometric turbidity meter (expressed in NTU). Conductivity (EC) and TDS: The pH was measured electrometrically by use of a calibrated portable pH meter. Anions (Cl⁻, SO₄²⁻): The quantification of Chloride was done through Argentometric titration (Mohr’s method) and for Sulfate analysis the turbidimetric method was employed. Organic Load (BOD/DO): A digital DO meter was used to measure Dissolved Oxygen while BOD was calculated by subtracting the initial DO from the final DO after incubation for 5 days at 20°C Cations and Trace Metals: The analysis of sodium, calcium, magnesium, copper, and iron was done by atomic absorption spectrophotometry (AAS). 3.4 Statistical and Risk Assessment Models The study was taken a step further from just being a description using the following analytical models: 3.4.1 Water Quality Index (WQI) The WQI provides an aggregate and unitless indication of the water quality. It was calculated using the weighted arithmetic index method (Amadi et al., 2012): Where Qn is the quality rating of the n-th parameter and Wn is the unit weight. www.ijprems.com [email protected] INTERNATIONAL JOURNAL OF PROGRESSIVE RESEARCH IN ENGINEERING MANAGEMENT AND SCIENCE (IJPREMS) (Int Peer Reviewed Journal) Vol. 05, Issue 12, December 2025, pp : 427-435 e-ISSN : 2583-1062 Impact Factor : 7.001 @International Journal Of Progressive Research In Engineering Management And Science 430 3.4.2 Human Health Risk Assessment (HHRA) In this research, an assessment was made on the potential health danger from consuming groundwater, excluding cancer. To determine the CDI, the following formula was employed: Where: C = Concentration of the contaminant (mg/L). I R = Ingestion Rate (2 L/day for adults). EF = Exposure Frequency (365 days/year). ED = Exposure Duration (30 years for adults). BW = Body Weight (70 kg for adults). AT = Averaging Time (ED × 365 days). The Hazard Quotient (HQ) was then determined: Where Rf D is the oral Reference Dose (mg/kg/day) given for each metal (Fe = 0. 7, Cu = 0. 04). Fe and Cu stand for Iron and copper, respectively. A possible harmful effect on health is represented by H Q when it exceeds 1. 4. RESULTS AND DISCUSSION In Odi, seven sampling stations provided hydrogeochemical data as shown in Table 1. It can be seen from the findings that there is an interaction of different factors, whereby the geochemical composition within the Benin Formation is naturally modified while at certain points man intervenes (Nwankwoala & Peterside, 2019). Table 1: Physio-chemical Analysis of Groundwater in Odi S/ N Sa mp le ID p H Te mp (°C) Col our (T CU ) Sali nit y (pp m) Cond uctivit y (µS/c m) Tur bidit y (NT U) TD S (m g/L ) Tota l Har dnes s (mg/ L) BO D (m g/L ) D O (m g/L ) Na (m g/L ) Mg (m g/L ) Ca (m g/L ) Cl (m g/L ) SO ₄ (m g/L ) Fe (m g/L ) 1 BH 1 6. 65 31 16 101 201 8.48 10 1 72.0 3.0 7.5 0 29. 30 12. 14 32. 50 14. 0 1.3 6 0.0 65 2 BH 2 6. 68 29 16 102 202 8.46 10 2 73.0 3.1 0 7.5 2 29. 35 12. 33 32. 48 14. 0 1.3 7 0.0 68 3 BH 3 6. 70 29 16 60 121 14.5 7 60 80.0 9.3 9.5 0 25. 39 12. 35 45. 00 10. 0 1.1 2 0.0 87 4 BH 4 6. 79 33 16 625 121 14.5 8 60 81.0 9.5 9.5 2 25. 40 12. 32 45. 20 10. 5 1.1 5 0.0 89 5 BH 5 6. 77 28 16 435 85 15.3 43 30.0 5.4 5 7.8 2 22. 48 7.9 5 20. 00 8.0 1.1 7 0.1 5 6 BH 6 6. 76 29 16 435 86 15.6 42 32.0 5.4 3 7.8 2 22. 50 8.0 20. 25 8.3 0 1.2 0 0.1 8 7 BH 7 6. 72 29 16 38 77 18.2 38 56.0 7.8 0 11. 0 19. 32 10. 58 30. 20 9.0 1.1 2 0.2 3 Ra ng e - 6. 65 - 6. 2933 16 38625 85202 8.4618.2 3810 2 3081 3.0 - 9.5 7.5 011. 0 19. 329. 3 7.9 - 12. 3 20. 045. 2 8.0 - 14. 0 1.1 - 1.3 0.0 60.2 3 www.ijprems.com [email protected] INTERNATIONAL JOURNAL OF PROGRESSIVE RESEARCH IN ENGINEERING MANAGEMENT AND SCIENCE (IJPREMS) (Int Peer Reviewed Journal) Vol. 05, Issue 12, December 2025, pp : 427-435 e-ISSN : 2583-1062 Impact Factor : 7.001 @International Journal Of Progressive Research In Engineering Management And Science 431 79 W H O 201 9 6. 58. 5 Am bien t 15 - 400 5 10 00 200 - - 20 - - 25 0 25 0 0.3 4.1 Physical Quality Assessment Hydrogen Ion Concentration (pH): The pH values were very close ranging from 6. 65 to 6. 79 thus showing that the hydrogeochemical environment was mildly acidic. Even though these figures are technically within the lower part of the acceptable WHO range (6. 5–8. 5) (WHO, 2022), they are close to being acidic. Groundwater in the Niger Delta is commonly acidic due to the breakdown of high amounts of organic materials on top soils and also the nature of the lateritic; with iron and alumina oxides (Etu-Efeotor, 1981). The area also experiences a lot of gas flaring which leads to acid rain penetrating through shallow water table thus reducing pH (Oki & Akana, 2016). This kind of water with such a pH profile is not very safe for human health but rather aggressive and corrosive. For instance, it may dissolve metals like lead or copper from home plumbing systems thereby creating secondary contaminants at the consumer end. Turbidity and Borehole Integrity: The study has revealed that the turbidity levels were very high, ranging between 8. 46 and 18. 2 NTU. These levels are double the acceptable turbidity unit (5 NTU) according to WHO (WHO, 2017) thereby making it a complete non conformer to the set standards. When it comes to ground water, turbidity may show that filtration was not enough or otherwise the wells may not be tight. It can be attributed to certain things that cause this high turbidity of the water in Odi: 1. Poor Borehole Construction: When there is no appropriate packing of gravel or when the casing is cracked, it enables the passage of fine silt and clay particles from the Benin Formation into the water column (Offodile, 2002). 2. Surface Infiltration: Due to the flood-prone nature of the locality, the natural soil filtering mechanism may not work well because surface flow that contains solids in suspension could be bypassing it and passing into the atmosphere at points around the wellhead. Turbidity goes beyond just looking bad; suspended matter may provide protection to harmful microorganisms hence diminishing the effectiveness of chlorination and posing enhanced hazard of epidemiological conditions through contaminated water. Electrical Conductivity (EC) and Total Dissolved Solids (TDS): The water is in the low mineralization class as EC (85–202 µS/cm) and TDS (38–102 mg/L) values indicate "fresh" groundwater. This is in agreement with the fast recharge rates for sands of the Benin Formation (Reyment, 1965). The water from rain washes the aquifer quickly, not allowing the salt to accumulate in solution. The low TDS means the water will be tasteless but bland, as there would be little to none mineral content. 4.2 Biochemical Indicators of Pollution BOD and DO Dynamics: It was observed that there was a wide ranging Biochemical Oxygen Demand (BOD) with values between 3. 0 to 9. 5 mg/L. When BOD is above 4 mg/L, it means that there is a high level of organic matter in the groundwater and it is not safe for human consumption unless properly treated first. It is peculiar to find high BOD even at such depths of the boreholes which could be attributed to failure of septic tanks, pit latrines or over flow from agricultural runoffs (Ugbaja & Edet, 2004). These observations agree well with the Dissolved Oxygen data which ranges from 7. 50 to 11. 0 mg/L. Normally, deep groundwater contains little DO. The high DO levels seen here indicate either that the water has been freshly infiltrated and is therefore properly oxygenated, or else there may be a lot of surface water mixing with it and causing turbulence. The short-circuiting of surface water and groundwater known as "short-circuiting" poses a serious threat to the aquifer during floods. 4.3 Geochemical Characterization (Major Ions and Metals) Cationic Profile (Na, Ca, Mg): The concentration levels of Sodium (Na) ranged between 19. 32 and 29. 34 mg/L. It is important to note that samples BH1, BH2, BH3, BH4, BH5, and BH6 had levels greater than 20 mg/L which is the recommended maximum by WHO (WHO, 2022). Although Na is not poisonous, too much of it can pose a danger to people with high blood pressure or heart related problems. This sodium may arise from geogenic sources such as weathering of feldspar or from anthropogenic sources like domestic sewage. The waters were found to be soft in relation to calcium (20–45. 2 mg/L) and magnesium (7. 95–12. 35 mg/L) (Nwankwoala & Peterside, 2019). www.ijprems.com [email protected] INTERNATIONAL JOURNAL OF PROGRESSIVE RESEARCH IN ENGINEERING MANAGEMENT AND SCIENCE (IJPREMS) (Int Peer Reviewed Journal) Vol. 05, Issue 12, December 2025, pp : 427-435 e-ISSN : 2583-1062 Impact Factor : 7.001 @International Journal Of Progressive Research In Engineering Management And Science 432 Heavy Metals - The Iron Question: There was a variation of iron (Fe) concentration from 0. 065 to 0. 23 mg/L. It was interesting that all the samples were within the WHO aesthetic limit; less than 0. 3 mg/L (WHO, 2022). High iron content is a common feature of groundwater in Niger Delta (Etu-Efeotor, 1981). The observation of low iron in Odi than expected could be due to the fact that there was much DO. In environments with high DO, the soluble ferrous iron (Fe2+) is quickly transformed into the insoluble ferric iron (Fe3+), which then precipitates before reaching the sampling point. Nevertheless, even these trace amounts are significant since monitoring is necessary because iron bacteria may develop in the wells leading to biofouling and bad smell Table 2: Pearson Correlation Matrix of Selected Parameters pH Turbidity TDS BOD Na Fe pH 1.00 Turbidit y -0.12 1.00 TDS 0.05 -0.68 1.00 BOD 0.23 0.82 -0.45 1.00 Na 0.11 -0.34 0.78 -0.12 1.00 Fe -0.08 0.56 -0.41 0.61 -0.22 1.00 Potential sources were identified through Pearson correlation analysis. The turbidity and BOD had a high positive correlation coefficient (r = 0. 82). The data implies that the hypothesis stands; the suspended particulate matter is either made up of living organisms or non-living matter that carries organic pollutants. In addition, there is a high relationship (r = 0. 78) between TDS and sodium which means that NaCl forms a big part of the soluble substances found in the underground water. 4.4 Human Health Risk Assessment (HHRA) The calculation of Hazard Quotient (HQ) for Iron and Sodium was done to determine the degree of threat because they were the major metallic elements detected. Table 3: Health Risk Assessment Values (Adults) Parameter Max Concentration (mg/L) CDI (mg/kg/day) RfD (mg/kg/day) Hazard Quotient (HQ) Iron (Fe) 0.23 0.0065 0.7 0.009 Sodium (Na) 29.35 0.838 N/A* Low Risk Note: Sodium does not have a strict EPA RfD for toxicity but has a dietary advisory limit. Iron’s Hazard Quotient is 0. 009, a value that is far below unity (HQ≪1). This means that right now, the people living in Odi are safe from a non-cancer iron toxicity through eating since the HQ for Iron is way below one at 0. 009. Nevertheless, with regards to the study on hydrochemistry, even though it may have an optimistic approach; considering the BOD and turbidity levels, it seems that there would be a great risk/hazard of assessment in relation to biotic nature for the ones who drink water from the sources. 4.5 Spatial Heatmap Analysis www.ijprems.com [email protected] INTERNATIONAL JOURNAL OF PROGRESSIVE RESEARCH IN ENGINEERING MANAGEMENT AND SCIENCE (IJPREMS) (Int Peer Reviewed Journal) Vol. 05, Issue 12, December 2025, pp : 427-435 e-ISSN : 2583-1062 Impact Factor : 7.001 @International Journal Of Progressive Research In Engineering Management And Science 433 Figure 2: Placeholder: Spatial Heatmap of Key Parameters in Relation to WHO Standards Description: From the spatial heatmap visualized from the data (Amadi et al., 2012), it can be observed that there is a cluster of boreholes with high BOD and Turbidity near the center of the community where there is high population density (BH3, BH4). This spatial pattern implies that the quality of groundwater is affected by urbanization with regard to the closeness of septic tanks. However, the levels of TDS and Conductivity are about the same throughout the study area and can be attributed to regional geology not specific pollution of any kind. 5. CONCLUSION This study has provided a detailed hydrogeochemical evaluation of the groundwater resources in the Odi community, moving beyond basic monitoring to incorporate risk assessment and statistical source tracking. The following conclusions are drawn: 1. Potability Status: 1. Potability Status: In Odi, the chemical nature of groundwater can be described as "fresh" and "soft" since the levels of heavy metals are mostly within the permissible range. Nevertheless, this water does not comply with WHO standards in terms of Turbidity and Biochemical Oxygen Demand (BOD) (WHO, 2022). It is evident from the high levels of turbidity that there is a lot of physical contamination, and the increased BOD means that organic matter is being added in large amounts. 2. Mechanism of Contamination: Due to the fact that there exists a strong correlation between Turbidity and BOD; with addition to this having a shallow water table but experiencing high rainfall; then it can be inferred that the aquifer is not well protected and susceptible to contamination from the surface (Ugbaja & Edet, 2004). This compromises with the natural filtration capacity of the soil probably because of incorrectly constructed boreholes as well as the annual floods which move around contaminants on the surface. 3. Health Implications: Although the Chemical Health Risk Assessment (HQ < 1) shows that chronic toxicity risk is not significant for heavy metals such as Iron, there is still a danger posed by the physical and organic aspects. Turbidity, which is very high, may hide some pathogens, while the increased amount of sodium calls for attention of people with high blood pressure. 4. Necessity of Treatment: Contrary to what people in Niger Delta believe that borehole water is clean, these findings disprove that notion. Odi’s water needs to be treated before anyone can drink it straight out of the tap. 6. RECOMMENDATIONS The recommendations below can be implemented to protect people’s health and to make sure that there will still be enough water for tomorrow in Odi (Jakeman et al., 2016): 1. Implementation of Point-of-Use Treatment: Filtration: Ceramic candle filters or sand filters are important turbidity control measures that people living in these areas need to adopt. www.ijprems.com [email protected] INTERNATIONAL JOURNAL OF PROGRESSIVE RESEARCH IN ENGINEERING MANAGEMENT AND SCIENCE (IJPREMS) (Int Peer Reviewed Journal) Vol. 05, Issue 12, December 2025, pp : 427-435 e-ISSN : 2583-1062 Impact Factor : 7.001 @International Journal Of Progressive Research In Engineering Management And Science 434 Disinfection: Because of the elevated BOD, it is necessary to boil or add chlorine so as to get rid of biological hazards. pH Correction: Limestone chips may be employed in storage tanks to neutralize mild acid hence safeguarding plumbing systems. 2. Structural Integrity Improvements: New boreholes must have correct grouting and sanitary seals (concrete aprons) so as to stop any surface water runoff flowing inside the casing. The wellheads must be elevated to a minimum height of 0. 5 meters above the maximum flood level of the River Nun as we know it. 3. Zoning and Sanitation: To minimize the migration of the organic plume, there must be at least 30 meters setback between boreholes and septic tanks/pit latrines. 4. Continuous Monitoring: To track how contaminants move in flood waters, there is need for a monitoring plan that will occur at particular times of the year when one season is changing into another; for example from dry to wet season or vice versa (Ngah & Nwankwoala, 2013). 7. REFERENCES [1] Adelana, S. M. A., & MacDonald, A. M. (2008). Groundwater research issues in Africa. In Applied Groundwater Studies in Africa (pp. 1–26). CRC Press. [2] Amadi, A. N., Olasehinde, P. I., Yisa, J., Okosun, E. A., & Nwankwoala, H. O. (2012). Geostatistical assessment of groundwater quality from coastal aquifers of Eastern Niger Delta, Nigeria. Geosciences, 2(3), 51–59. 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