Spatial Distribution of Groundwater Quality in Kitwe District, Copperbelt Province, Zambia: A Case Study of Mulenga Informal Settlement

Abstract

In most informal settlements in Zambia, access to piped water and proper sanitation system still remains a challenge. This has led to people in these settlements to rely on groundwater from shallow wells which are either protected or unprotected. In terms of human waste disposal, the majority of the people depend on traditional pit latrines. In order to help protect and sustainably manage the groundwater resources, a study was undertaken to investigate groundwater quality and its spatial distribution in Mulenga informal settlement in Kitwe district, Copperbelt Province, Zambia. A total of twenty eight (28) groundwater samples were collected from twenty eighty (28) wells in the aforementioned settlement. The samples were analysed for total dissolved solids (TDS), turbidity, total suspended solids (TSS), pH, sulphates, nitrate, total and faecal coliforms using standard techniques. Results were compared with the Zambian Bureau of Standards (ZABS) guideline values for drinking water and in some cases, with WHO guideline values. In terms of microbiological parameters, all water samples in Mulenga informal settlement tested positive for total and faecal coliforms. Parameters such as TDS, TSS and sulphate complied with ZABS drinking water guideline values. Other parameters which include turbidity ranged from 0 to 52NTU, pH from 5.1 to 6.8 and nitrates from 1.6 to 35.6mg/L did not comply with ZABS drinking water guideline values at the majority of the wells. Spatial distribution maps revealed that larger parts of Mulenga informal settlement display pH values less than ZABS and WHO minimum permissible value of 6.5 while sulphate and nitrate levels ranged from 1 to 20mg/L and 10 to 20mg/L respectively. In terms of turbidity and TDS, their spatial distribution maps display significantly high turbidity levels (>20NTU) in the south-eastern and some north-western parts of Mulenga informal settlement while slightly high TDS values (>500m/L) were displayed in south-eastern and north-western parts of the settlement. The highest numbers of total and faecal coliforms were concentrated in the north-eastern and central parts of Mulenga informal settlements.