ASSESSING THE POLLUTION STATUS OF RIVER KAPINGAZI EMBU COUNTY, KENYA

Abstract

Water resources confronts immense pressure from human needs, climate change variation, and pollution, which is a major environmental problem. Available literature focuses more on the sources of riverine pollution and their effects on human health. Characterization of the sources of water pollution in the river Kapingazi has not been done necessitating this study. The goal of the research was: to determine different land uses contributing to water pollution in River Kapingazi catchment, Embu County; to evaluate the extent of pollution in River Kapingazi; and to assess the water pollution mitigation measures adopted for River Kapingazi Embu County. For objective one, satellite images (LANDSAT) were utilized to classify the land use land cover (LULC) using supervised maximum likelihood classification. The study analyzed 96 water samples from four locations in a span of eight months which combined the dry and wet seasons of the year to analyze objective two. Parameters measured in-situ included turbidity, pH, total dissolved solids (TDS), temperature, dissolved oxygen (DO) and electrical conductivity (EC) determined using calibrated portable multiparameter analyzer H19829, while ex-situ parameters were salts (phosphates and nitrates) measured using calibrated UV 1800PC and concentrations of heavy metals (iron and Manganese) determined through lab analysis using Atomic Absorption Spectrophotometer. In objective three, a cross-sectional survey design was employed to solicit data from 385 respondents with the aid of a semi-structured questionnaire. Data obtained were cleaned and coded before analysis through descriptive statistics presented in tables, percentage and frequencies, and inferential statistics which employed generalized linear model (GLM), probit model and ordinary least square (OLS) regression model. Results show that tree cover has been decreasing over time while crop land and built areas have been increasing. Water Quality Index (WQI) during the drought period was measured to be 74.05, suggesting that the water quality is only recommended for agricultural and industrial applications. In wet season, the WQI was measured to be 89.67, reflecting a poor status, as more contaminants were likely introduced through surface runoff. This study concludes that there is a sharp decline in tree cover owing to land use operations, which could impact directly on water quality. The water in River Kapingazi is not suitable for human consumption, hence appropriate treatment is essential prior to its use. Involving stakeholders such as NEMA, WRA, EWASCO and Ministry of Agriculture and supporting community programs were crucial strategies in enhancing the water quality outcomes. Measures that prioritize the sustainability of the environment should be emphasized. It is also recommended that the directing resources towards water treatment systems and the regulation of pollution sources ought to be enforced to ensure the safety of river water for diverse applications. Additionally, these findings highlight the significance of collective participation in technical plannnery and cohesive governance towards the safeguarding of riverine ecosystems.