A time series analysis of fresh water quality in the Greater Plettenberg Bay Municipality, Western Cape Province

Abstract

This study aimed to analyse the variation of recreational water quality in Plettenberg Bay in an attempt to comprehend the effects of pollution on the environment, and more specifically the potential impacts on the quality of surface water used for recreational activities. Plettenberg Bay is a major destination for tourists in South Africa, with recreational water activities representing an important attraction and contributor to the local economy. The study analysed the specific water quality parameters and their variation over five years. Water and its recreational use have a paramount importance for the economy and ecology, and this requires the solid implication of authorities and the community to conserve its quality for the benefit of all. Therefore, the importance of constant monitoring and analysis of water quality cannot be overemphasised if water must be kept clean and well-managed. For this study, data were obtained from Bitou Municipality, the local authority in charge of the water monitoring program in Plettenberg Bay. The selected datasets contained water quality data collected by the Bintou Municipality waterworks department in three sampling sites in Plettenberg Bay. The samples were tested for six water quality parameters namely, Ammonia, Suspended Solids, Conductivity, Nitrates/Nitrites, pH, and E coli. Microsoft Excel was used extensively to analyse and present the data. Furthermore, published literature was used to identify how chemicals react in surface waterbodies and how their behaviour has impacted the overall quality of water. To ensure that water quality is safe enough for full-contact recreational activities, drinking water standards prescribed by The South African National Standards (SANS 241:2015) were used as the standard of reference in the analysis of data. Although this study focused on recreational water, using drinking water quality standards allowed for a better-quality control in this study. The general trends observed showed a certain level of stability over the five years. Although the concentration of some parameters varied throughout the years, it was noted that most of them did not exceed permissible values, with only a few chemicals showing a more erratic trend in their concentration levels. In all, it is recommended that the Bintou Municipality increase the sampling frequency to allow a clearer understanding of water quality variation and to minimise potential uncertainties.