Iron removal in Borehole water: A case study of Luapula Province

Abstract

Supply of clean drinking water in the rural areas is a high priority of the Government of the Republic of Zambia (GRZ). More than 65 percent of the population of Zambia live in rural areas. The rural population is characterized by low access to basic services including safe water supply and sanitation. The Government with support from Cooperating Partners (CPs) formulated the National Rural Water Supply and Sanitation Program (NRWSSP) to guide interventions in the rural areas. The overall goal is to provide sustainable access to water supply and sanitation in rural areas A research study was carried out to ascertain the efficiency of Iron Removal Technology (IRT) in four rural districts of Luapula Province, namely Mansa, Milenge, Mwense and Samfya. The “before-and-after” study design was utilised by comparing the difference in the iron concentration before and after Iron Removal Plant (IRP) intervention in assessing IRP performance. An inventory of existing boreholes under the Japan International Corporation Agency (JICA) phase one groundwater development project was conducted with sampling done at some of the water points. To ascertain the levels of iron concentration in the water, different samples were taken from the water points for immediate field analysis and later for laboratory analysis. Multistage (cluster) sampling was used in picking respondents for the questionnaire survey in assessing the effectiveness of operation and maintenance. Pump tests were conducted to ascertain the main source of iron in the water. Different retention times were tested within one hour of sampling in ten minute intervals to assess its effect on iron concentration. The filter bed depth was upwardly adjusted to ascertain its effect on iron concentration in the water. The result from the performance evaluation process of the current IRP’s showed 85.6 to 92.5 percent performance efficiency respectively. From the pump tests conducted, it was observed that the iron concentration in the water increased over time with continuous pumping. Results from a t-test analysis showed no significant difference (P < 0.05) in iron concentration between water points installed with Indian Mark II pumps in comparison to those installed with the Afridev pump. The results showed remarkable iron removal with increased retention time. The strategies for operation and maintenance were not very effective due to the attitudes and perceptions of the users. Government capacity to operate the IRP was found to be limited due to inadequate funding and lack of devolution. The results obtained showed that there was a reduction of 88.1 percent iron concentration in the water with the sand bed depth adjustment of 18 to 36 cm with the highest iron reduction observed between 27 and 30 cm.