EFFECT OF HUMAN ACTIVITIES ON GROUNDWATER QUALITY IN RURAL AND PERI-URBAN AREAS: A CASE OF KANDUYI SUB-COUNTY, BUNGOMA COUNTY, KENYA

Abstract

Human activities and land use changes stand as the primary drivers of groundwater pollution, a consequence of growth in population, urban expansion, and heightened demand for farming and the escalated application of chemicals to enhance agricultural yields in response to growing food needs. These endeavors exert adverse impacts on groundwater quality. The central goal of the research was to analyze the influence of human activities on groundwater quality in rural and peri-urban areas of Kanduyi, Bungoma County. This main objective was realized through the pursuit of the subsequent specific aims: evaluating the sanitary-related risk factors contributing to the deterioration of water quality in wells and springs within Kanduyi, Bungoma County; ascertaining the physicochemical and bacteriological attributes of water from the existing wells and springs in the area; and assessing the water quality index for wells and springs in the seven wards of Kanduyi sub-county, Bungoma county. Total of 89 wells and 10 springs were selected by simple random technique through randomization principle to avoid biasness. Human activities neighboring water sources were investigated using structured questionnaires administered via the online mWater application. These questionnaires were completed during field visits and subsequently subjected to analysis. The study scrutinized the sanitary conditions of eighty-nine wells (89) and ten springs (10), gauging their susceptibility to contamination in connection with human activities and potential risk elements. This process involved assessment and categorization of risk levels. Moreover, samples from these sources were gathered and subjected to testing in a water laboratory, evaluating seven physicochemical parameters (pH, turbidity, electrical conductivity, total dissolved solids, nitrates, sulphates, and phosphates) as well as two bacteriological parameters (total coliform counts and E. coli presence). The results of physicochemical parameters were utilized to establish a Water Quality Index for each source. The findings demonstrated that the examined waters contained phosphates and nitrates at levels ranging from 0.39 to 24 mg/l and 1 to 51 mg/l, respectively, significantly exceeding both the recommended thresholds set by Kenya Bureau standards and the drinking water quality standards stipulated by the World Health Organization. Furthermore, inadequate drainage (58%) emerged as a potential contamination risk factor through runoff. The study employed Weighted Arithmetic Mean concept to calculate Water Quality Index and found that 6% of the wells and 50% of the springs in the study area exhibited CWQI values falling between 38 and 50, categorizing them as 'good.' Conversely, a majority of the wells (58%) exhibited Water Quality Index values ranging from 103 to 458, rendering them unsuitable for consumption because according to categorization or rating scale, any CWQI values >100 are deemed to be unfit for consumption. This state of quality is attributed to revelation that most of the wells were found to have contamination risk factors such as proximity to sanitation facilities, inadequate well covers, poor modes of solid waste disposal, carrying out farming and washing clothes from near the wells and springs. The research recommends that public health authorities in the County, along with other stakeholders, ought to heighten awareness regarding the necessity of utilizing government-approved disposal sites for solid waste. Stringent control over farming activities and washing practices near water sources should be implemented to mitigate contamination. Additionally, the study recommends that pertinent water authorities formulate groundwater management policies to guide and regulate the construction, siting, and periodic quality monitoring of these sources