Assessment of the Baseline Characteristics of Groundwater in Igbo-Ukwu and Environs, South-Eastern Nigeria.

Igbo-ukwu and its environs are located within Anambra State, Southeastern Nigeria, and lie within latitudes 5°56' to 6°4' N; and longitude 6°54' to 7°8'E. The composition of groundwater in the study was assessed and characterized to determine the chemical behaviour of the groundwater system within the area. Twenty (20) representative groundwater samples were randomly collected and subjected to physico-chemical analysis using titration, evaporation, atomic absorption spectrophotometer (AAS), and other standard equipment. These quality indicators are namely: pH, temperature, total hardness, electrical conductivity, total dissolved solids, salinity, Ca2+, Mg2+, Na+, K+, HCO3-, CO32-, SO42-, Cl-, NO3-, Fe2+, Cu2+ and Mn2+. The pH mean value (5.75) indicates the water is slightly acidic, and the total dissolved solids (TDS) and electrical conductivity (EC) values showed that it is fresh water. All other parameters fall within WHO 2017 guidelines except Feacal Coli and Total Coli, which exceed 5 and 8 samples respectively. Residual Sodium Carbonate (RSC) and EC values revealed that the groundwater is 100% suitable for irrigation purposes, Magnesium Hazard (MR) values also indicate 25% suitable. With the aid of geochemical diagrams acquired using Grapher Golden Software, groundwater samples were classified into their respective hydro-geochemical facies, identified their relative similarity, and demonstrated the irrigability of the groundwater. Three hydro-geochemical facies were identified in the area using a Piper diagram and they are the Calcium Bicarbonate water type (50%), the Sodium Bicarbonate water type (45%), and the Calcium Sulphate water type (5%). The dominant cation is Magnesium ion, as the anion is Bicarbonate ions. The primary character of the waterfalls within the alkaline earth metals (Ca, Mg) exceeding alkali metals (K, Na) and weak anions (HCO3-, CO32-) exceeding strong acidic anions (SO42-, Cl-). In conclusion, using chlorine in groundwater treatment is essential in ensuring the safety and quality of water; from the growth of harmful microorganisms, for drinking, agricultural and industrial purposes. Proper monitoring of the area's water resources should be carried out consistently to monitor pollution, and remediation should be carried out when necessary. The government should also discourage the use of pit latrines as well as passing feces on land since these constitute environmental hazards.