SURFACE WATER QUALITY IN KENYA’S URBAN ENVIRONMENT: A CASE STUDY OF GITHURAI, NAIROBI, KENYA

  • P. G. Home Biomechanical and Environmental Engineering Department, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya
  • C. Wageci Biomechanical and Environmental Engineering Department, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya
  • J. W. Kaluli, Biomechanical and Environmental Engineering Department, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya
Keywords: Sanitation, informal settlement, water quality, BOD, TSS, TDS

Abstract

Safe, clean drinking water and sanitation facilities are key to economic development and public health in Kenya.
Rapid urbanization and population growth mean worsening conditions for millions of Kenyans, especially the
poorest. Sanitation is one of the greatest problems especially in the informal settlements where 60% of the people
in the urban centers reside. In fact, 50% of all preventable illnesses in Kenya are water, sanitation and hygiene
related. This study was done to establish the level of indicator water quality parameters, and establish water borne
disease prevalence in Githurai and adjacent communities. Water samples were collected from 6 points distributed
uniformly along Kiu River in Githurai. Using standard methods, the samples were analyzed for Dissolved Oxygen
(DO), BOD, TSS and TDS in the JKUAT environmental laboratory. A survey was also done in Githurai, Kahawa Sukari
and Kahawa Wendani to establish the prevalence of water borne diseases. Data was collected from local medical
clinics and Ruiru District Public Health Office. Randomly selected individuals were also interviewed to establish the
frequency of visits to health facilities. The study revealed that dissolved oxygen in surface water was between 1.5
and 8.5 mg/L while biochemical oxygen demand (BOD) was between 200 and 400 mg/L. This was much higher than
NEMA standards for surface water which demand that the BOD of any effluents to be discharged into surface
water should be less than 30 mg/L. Total suspended solids (TSS) varied from 900 to 950 mg/L. NEMA allows
domestic water not to have TSS of more than 30 mg/L. Total dissolved solids (TDS) were in the range of 3000 to
9000 mg/L compared to a maximum of 1200 mg/L which is allowed by NEMA. Surface water in Githurai is highly
polluted and poses public health risks. Some 30-40% of all patients visiting hospitals in the study area suffered
from diarrheal diseases and the average resident in Githurai was treated for water borne diseases once every
three months. Therefore, an urgent intervention is required to clean up Kiu River and stop further contamination
of the river.

Published
2019-05-16