This study investigated effluent from herbal mixture industry and well water nearby effluent drainage. Effluent was sampled twice while well waters were sampled four times (July, August, December and January). All the samples collected were analysed for parameters including water temperature, apparent colour, turbidity, conductivity, total suspended solids (TSS), total dissolved solids (TDS), dissolved oxygen (DO), biological oxygen demand (BOD), chemical oxygen demand (COD), SO42-, NO3-, PO43- and Cl- using standard methods. Sodium, K, Mg, Ca Cd, Cr, Cu, Fe, Mn, Pb and Zn were also determined using Atomic Absorption Spectrophotometry (AAS). The study revealed that the colour of the untreated herbal mixture effluent was black, and turbid in appearance with unpleasant odour. Ranges of turbidity (140.8±0.057 – 144.11±0.157 NTU), apparent colour (1579.35±0.071 – 1643.32±0.821 Pt.-Co.), BOD (20.05±2.828 – 24.40±0.566 mg/L), COD (297.87±0.431 – 301.01±0.041 mg/L), TSS (639.0±12.73 – 643.0±1.414 mg/L) and PO43- (6.571±0.071 – 6.793±0.004 mg/L) were above Nigerian standards- National Environmental Standards and Regulations Enforcement Agency (NESREA). However, well water alkalinity, pH, water temperature, apparent colour, turbidity, conductivity, TSS, TDS, COD, SO42-, NO3-, PO43-, Cl-, Ca and Fe values were significantly (p < 0.05) different between and within the wells. The mean vales of pH, DO, BOD, TSS, PO43-, and Pb of some wells located close to the effluent drainage were above World Health Organisation (W.H.O.) drinking water quality standard. The range of values obtained in the entire wells for apparent colour, turbidity, COD, Cd and were above W.H.O. standard.
The study concluded that the level of pollution of herbal mixture effluents negatively impacted the well water in the study area.