Groundwater Quality Analyses along Kenyan Coastal Region, Case Study of Kilifi County

Year 2019, Volume: 6 Issue: 1, 1 - 14, 12.04.2019

Mary Makokha

https://doi.org/10.30897/ijegeo.466933

Cited By: 2

Abstract

The Kenyan coast is a semi-arid region frequently faced with severe water scarcity especially
during prolonged drought and a rapid population growth. Groundwater
provides 50% of the water demand and most sources are poorly drilled,
over-abstracted and abandoned. The aquifers occur in sedimentary formations of
fluvial and lacustrine origin. There is a need to have a groundwater  monitoring system in place; therefore this
study analyses selected physico- chemical and microbial parameters using both
laboratory and field methods. Arc-GIS 9.3, SURFER were used to generate
thematic maps for some tested parameters. Results indicate pH values within
acceptable range of 6.5 – 8.5, though shallow wells in Malindi were acidic,
this atrributed to the heavy industries prevalent in the area. Electric
conductivity (EC) was above the set standard of 1500µS/m indicating high
dissolved ions present especially in Magarini where salt mining is done. Total
dissolved solids (TDS) of up to 500mg/L suitable for drinking water was only
found during the wet season. Turbidity of less than 5 NTU was established in
most areas.  Chlorides and salinity
levels exceeded 250mg/L pointing to the saltwater intrusion problem that is a
challenge along Kenyan coastal aquifers  
Boreholes and shallow wells had a total hardness ranging from 50mg/L
-150mg/L indicating the water was ranging from being slightly hard to hard
water. Escheriria coli was present in
almost all the boreholes and shallow wells indicating the need to treat water
before use. Water Quality index (WQI) calculation indicate that groundwater is
unsuitable for human consumption in dry season.

Keywords

Groundwater, boreholes, water quality

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