African Journal of
Environmental Science and Technology

  • Abbreviation: Afr. J. Environ. Sci. Technol.
  • Language: English
  • ISSN: 1996-0786
  • DOI: 10.5897/AJEST
  • Start Year: 2007
  • Published Articles: 991

Full Length Research Paper

Irrigation water quality analysis of Mitheu Stream in Machakos Municipality, Kenya

Linge Kitulu
  • Linge Kitulu
  • Department of Environmental Science and Education, School of Environmental studies, Kenyatta University. P. O. Box 43844-00100, Nairobi, Kenya.
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Julius Kioko Nzeve
  • Julius Kioko Nzeve
  • Department of Environmental Sciences, School of Environment and Natural Resources Management, Machakos University, P. O. Box 136, Machakos, Kenya.
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Fuchaka Waswa
  • Fuchaka Waswa
  • Department of Agricultural Science and Technology, School of Agriculture and Enterprise Development, Kenyatta University, P.O. Box 43844-00100, Nairobi, Kenya.
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Esther Kitur
  • Esther Kitur
  • Department of Environmental Science and Education, School of Environmental studies, Kenyatta University. P. O. Box 43844-00100, Nairobi, Kenya.
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Douglas Shitanda
  • Douglas Shitanda
  • Department of Mechanical Engineering, School of Engineering and Technology, Machakos University, P. O. Box 136, Machakos, Kenya.
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  •  Received: 29 April 2020
  •  Accepted: 15 July 2020
  •  Published: 30 September 2020

Abstract

Water samples for physico-chemical, heavy metals and bacteriological analyses were collected from 4 selected points along Mitheu Stream flowing through Machakos Municipality once every month from June 2019 to September 2019. The samples were analyzed in Kenya Plant and Health Inspectorate Service and Water Resources Authority laboratories then data subjected to one-way analysis of variance to test significant differences (P≤0.05). The results were compared with World Health Organization guidelines to assess the suitability of the water for irrigation use. Results showed that the levels of the Biological Oxygen Demand and the Chemical Oxygen Demand in Mitheu Stream were higher than critical values permitted by the World Health Organization for irrigation water. Nitrates and Sulphates were within critical limits; however, Phosphates were higher than permissible limits at all the sampling points. Heavy metals concentrations for Cu, Pb, Zn and Cr were within allowable limits for irrigation water, but Cd was above the limit. Both total coliforms and Escherichia coli counts exceeded allowable limits for irrigation water. As such, Mitheu Stream can be considered polluted and the water unfit for irrigation farming. The Municipal authorities, working with other relevant stakeholders should take appropriate measures to mitigate stream pollution from untreated effluent discharged into the stream.
 
Key words: Physico-chemical, heavy metals, total coliforms, effluent.