Abstract
The seasonal variation and quality status of groundwater systems of Kamiti-Marengeta sub-catchment were evaluated through analysis of boreholes and 17 shallow wells water samples in May 2016 and September 2017. Consequently, the results were compared against the Kenya Bureau of Standards (KEBS) and World Health Organization (WHO) guidelines for drinking water purposes, and its suitability for drinking was established. The results showed that turbidity, calcium, potassium, iron, and fluoride levels in some of the boreholes and pH, calcium, sodium, and iron levels in some shallow wells exceeded the KEBS and WHO standards for drinking water quality. Turbidity, dissolved oxygen, and total hardness significantly varied across the regions of the study, and one-way ANOVA (P < 0.05) indicated a significant difference in the mean concentration of electrical conductivity, turbidity, total hardness, calcium, and iron in boreholes and in all parameters in shallow wells except for magnesium during the two seasons. The findings of this study provide baseline information on the quality of the groundwater systems of the area. It also contributes to knowledge on seasonal variation of groundwater quality of volcanic aquifers like the Nairobi Aquifer System (NAS) which is important for water quality monitoring.
Highlights
The results showed that turbidity, calcium, potassium, iron, and fluoride levels in some of the boreholes and pH, calcium, sodium, and iron levels in some shallow wells exceeded the Kenya Bureau of Standards (KEBS) and World Health Organization (WHO) standards for drinking water quality
It contributes to knowledge on seasonal variation of groundwater quality of volcanic aquifers like the Nairobi Aquifer System (NAS) which is important for water quality monitoring
The outcome of this study provides baseline information on the quality of the groundwater systems of the area; knowledge on the inter-seasonal variation of groundwater quality on a volcanic aquifer whose main aquifer unit is unconfined in the recharge zone but progressively gets confined and thins towards the end at the confined and thin area; knowledge on how water quality varies within an aquifer and factors determining these; and information that can help Water Resources Authority and the County Government in coming up with strategies to address groundwater quality problems and mitigation measures to ensure the provision of safe water to residents
Summary
The concept of water quality has become so important because it affects the use of water resources as well as human and ecological health. According to Knox & Marston, rapid population growth has created a significant amount of stress on local, regional, and global environments [2]. Today the world faces various challenges in meeting both the ecological and human water demands. The increase in human population, rapid urbanization, rising living standards across the world, poor waste management, and environmental degradation put freshwater resources under increasing stress
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
