[01] Kenny Nyirenda, Department of Geology and Survey, Copperbelt University, Kitwe, Zambia. [02] Sydney Nonde Sichilima, Department of Environmental Engineering, Copperbelt University, Kitwe, Zambia. [03] Bwalya Lydia Mwale, Department of Environmental Engineering, Copperbelt University, Kitwe, Zambia.

In Mpongwe district of Zambia, farming is the major economic activity and is heavily dependent on the use of agrochemicals such as chemical fertilizers. However, excessive application of chemical fertilizers can pollute groundwater with nutrients. It is from this background that a study was undertaken in Mpongwe farming block to determine the seasonal variations of nitrate and phosphate levels in groundwater and their implication on the health of consumers and the ecosystem. Sixteen (16) water samples were collected from the same wells during both dry and rainy seasons and analyzed for nitrate and phosphate using the calorimetric method. A comparison of the concentrations of nitrate and phosphate in collected water samples was then made to determine if there are any seasonal variations of the aforementioned parameters in groundwater. The laboratory analysis revealed that concentrations of nitrate from water samples collected during the dry season ranged from 0 to 1.9mg/L with the mean of 0.4mg/L while those collected during the rainy season ranged from 0.03 to 2.2mg/L with the mean of 0.6mg/L. Concentration of phosphate in water samples collected during the dry season ranged from 0.1 to 7.43mg/L with the mean of 1.8mg/L while those collected during the rainy season ranged from 0.3 to 7.7mg/L with the mean of 2.2mg/L. The result of this study revealed that nitrate and phosphate concentrations in water samples collected during the rainy season where slightly higher than those sampled during the dry season. Variations in concentrations of these nutrients in groundwater samples collected during the rainy season could be attributed to the usage of chemical fertilizers by farmers in the area during the rainy season. However, concentrations of nitrate in all water samples complied with the Zambia Bureau of Standards (ZABS) and World Health Organization (WHO) drinking water maximum permissible limit of 10mg/L and 50mg/L respectively. With phosphate, there are currently no set standards, but the concentrations recorded for both parameters in all water samples is likely to have no negative effect on the health of the consumers and the ecosystem.

Nitrate, Phosphate, Groundwater, Mpongwe Farming Block, Zambia

[01] International Groundwater Resources Assessment Centre, IGRAC (2013). Groundwater Monitoring in SADC Region. [02] Zambia Environmental Management Agency. (2012). An Environmental and Social Impact Assessment for Musakashi River Catchment and its Tributaries: an independent impact assessment of industrial mining waste pollution in Chambishi. [03] Department for International Development (DFID). (2015). Baseline assessment for Lusaka – prepared for FRACTAL. [04] Smedley, P. (2001). Groundwater quality: Zambia. [05] Nyambe I. A., Feilberg M (2009). Zambia National Water Resources for WWDR. [06] United Nation. (2013). Zambia: Country Brief. [07] Custodio E. (2014). Trends in Groundwater Pollution: Loss of Groundwater Quality & Related Services. Groundwater Governance: a Global Framework for Action, GEF-World Bank-UNESCO. [08] Norrgren, L., Pettersson, U. R. N. S., Örn, S., & Bergqvist, P. A. (2000). Environmental monitoring of the Kafue River, located in the Copperbelt, Zambia. Archives of environmental contamination and toxicology, 38 (3), 334-341. [09] World Bank. (2009). Zambia Managing Water for Sustainable Growth and Poverty Reduction. Washington, DC: World Bank. [10] Lindahl J., (2014). Environmental Impacts of Mining in Zambia. Towards better Environmental Management and Sustainable Exploitation of Mineral Resources. Geological Survey of Sweden. [11] Pavelic P., Giordano M., Keraita B., Ramesh V., Rao T. (2012). Groundwater Availability and use in Sub-Saharan Africa: A Review of 15 Countries. Colombo, Sri Lanka: International Water. [12] Environmental Council of Zambia, ECZ (2008). Environmental Outlook Report 3 Management Institute (IWMI). [13] Mateo-Sagasta, J., Zadeh, S. M., Turral, H., Burke, J. (2017). Water pollution from agriculture: a global review. Executive summary. Rome, Italy: FAO Colombo, Sri Lanka: International Water Management Institute (IWMI). CGIAR Research Program on Water, Land and Ecosystems (WLE). [14] Manassaram, D. M., Backer, L. C., Messing, R., Fleming, L. E., Luke, B., & Monteilh, C. P. (2010). Nitrates in drinking water and methemoglobin levels in pregnancy: a longitudinal study. Environmental Health, 9 (1), 60. [15] World Health Organization. (2018). Water sanitation hygiene. (Available http://www.who.int/water_sanitation_health/diseases-risks/diseases/methaemoglob/en/). [16] Central Statistical Office Zambia (2012). 2010 Census of Population and Housing Volume 11 National Descriptive Tables. [17] Nyirenda, K., Kaputula, D., Ngulube, R. (2016). Spatial Distribution of Groundwater Quality in Kitwe District, Copperbelt Province, Zambia: A Case Study of Mulenga Informal Settlement. American Journal of Water Resources, 4 (5), 102-110. [18] Minnesota Pollution Control Agency (1998). Nitrate in Minnesota Ground Water: A GWMAP Perspective. [19] Water Resources Center. (2018). Phosphate in Environment (https://www.water-research.net/index.php/phosphates). [20] Ator, S. W., Denis, J. M. (1997). Relation of nitrogen and phosphorus in ground water to land use in four subunits of the Potomac River Basin (p. 26). US Department of the Interior, US Geological Survey. [21] Domagalski, J. L., Johnson, H. (2012). Phosphorus and groundwater: establishing links between agricultural use and transport to streams. US Geological Survey Fact Sheet, 3004, 2012.