On-Site Sanitation and Its Effects on the Recreational Waters of Nyali-Bamburi-Shanzu and Diani-Chale –Kenya

Abstract

This paper presents the effect of on-site sanitation systems on the recreational waters of Nyali-Bamburi-Shanzu and Diani-Chale tourist destinations along the Kenya Coast to establish the level of contamination in these lagoon waters frequented by tourists for swimming, diving and snorkeling. Water oozing out along the beaches near hotels or a clusters of hotels and that of lagoons in front of the beach hotels were sampled for laboratory examination to determine the levels of contamination by nutrients and micro-bacteria. Nitrites and E. coli –indicators of recent contamination by human wastes were of major interest. The sampling and analysis spanned the whole year to capture the four tourist seasons and the wet and dry periods of the year. The results of analysis established the in-effectiveness of the on-site sanitation systems in containing human waste. Topology and rock formation promoted transportation of contaminants downstream for measurable levels of nutrients and E.Coli to be detected in the lagoon waters. Nutrients and bacteria levels were higher in the lagoons in the wet periods than during dry weather. This was linked to of diffuse pollution from surface run-off, leachates from dumpsite, and discharges of contaminated water into the lagoons. Specifically for Diani-Chale, the levels of contamination were observed to be in sync with the peak tourist season, where the higher levels could be explained on account of the large number of people (tourist  plus  local people), which increased significantly as the number of local people increased to cash in on the opportunities the industry offered during this period only to decline to low contamination levels during the low-tourist season when the tourists return to their home countries and the local people move to their rural homes for farming activities. Variation of contaminant levels as a pattern due to migration of the people was not observed in the NBS study area on account the area being more urbanized, people depend on other sectors for their socio-economic activities. Overall, the contamination levels in the two study areas are generally still low. However, with increasing urbanization and investments in the tourism industry, the problem may grow to unacceptable levels and action needs to be taken to address it as an emerging problem.

Keywords: Lagoon waters, on-water activities, on-site sanitation, human waste management, contamination, nutrients, micro-bacteria, E. coli