Efficacy of Karie Waste Water Treatment Plant for Domestic Purposes Murang’a County, Kenya

Water is essential not only for life but also as the foundation of a nation’s green economy. However, inadequate access to clean and safe drinking water severely jeopardizes public health, especially in developing countries such as Kenya. This study was conducted in Murang'a County, Kenya. The aim was to evaluate the effectiveness of the Karie Wastewater Treatment Plant for residential use by examining key physical parameters (temperature, PH, Dissolved solids, electrical conductivity and Total Dissolved Solids) of wastewater before and after treatment. A total of 45 samples (500 ml each) were collected as grab samples from three sites, that is, the plant inlet, outlet, and a point along River Karie. The study was carried out during the dry season (January–February 2023) and the wet season (May–June 2023). In situ measurements of temperature, PH, dissolved oxygen (DO), electrical conductivity (EC), and total dissolved solids (TDS) were performed using standard methods and appropriate instruments (mercury thermometer, PH meter, DO meter, and conductivity meter). Results were compared against guidelines from the Kenya Bureau of Standards (KEBS) and the World Health Organization (WHO) to assess suitability for household water use. During the dry season, temperature and PH increased significantly, with mean values of 24.52 ± 1.20°C and 7.5 ± 0.5, respectively (p < 0.05). In the wet season, TDS and DO levels were notably higher, with overall mean values of 23.42 ± 0.2°C (temperature), 7.4 ± 0.3 (PH), 234 ± 0.52 (TDS), 5.7 ± 0.3 (DO), and 593 ± 0.13 (EC). While temperature and PH did not significantly differ among the sampling stations (p > 0.05), several physical parameters varied significantly between the two seasons. Although most parameters were within allowable limits for domestic water use, the elevated electrical conductivity indicates that additional treatment processes such as advanced filtration, ion exchange, or reverse osmosis are necessary to prevent pollution of River Karie.