Water quality assessment of streams draining the Akwapim Ridge of Ghana

Abstract

Surface water samples from seven streams on the Akwapim Ridge were analysed over a period of 1 year for various water quality parameters following standard methods prescribed in APHA, AWWA, WEF and AOAC. The study was carried out in order to assess the suitability of the streams for drinking and other domestic purposes. Additionally, the effect of land use activities was assessed. The study revealed that, generally, most of the physico-chemical parameters of the streams were below the World Health Organization (WHO) limits recommended for drinking water, with the exception of the levels of sulphate and conductivity in three of the streams (Opiafo: 224 mg/1, 908.5 μS/cm; Kwati: 221.3 mg/1, 920 μS/cm; and Ademi: 246 mg/1, 1292 μS/cm), respectively, which were above the WHO requirements. Nevertheless, taking these factors into consideration (except the sulphate and conductivity), the waters may be regarded as excellent and good for drinking and other domestic uses. Introduction Water, the source of life and human civilization has become one of the major issues of the 21st century. It is probably the most valuable natural resource available to man, without which nothing can survive. Unfortunately, in many areas of the world, it is not possible to obtain a ready source of pure drinking water. In addition to this, no other public health issue affects a large proportion of the population than that of drinking water. Thus, through the ages, the contamination of drinking water by both point (e.g. sewage disposal) and non-point (runoff from agricultural farms) sources of pollution have resulted in several catastrophes and human death. The supply of fresh water is an important role of rivers, springs and streams. For this reason, the quality of drinking water must be constantly monitored. Water quality relates to the chemical, physical and biological characteristics of water. The quality is often affected by both natural (e.g. types of soil, rocks and surface through which it flows) and anthropogenic activities (e.g. agricultural activities and mining). Hence, the key is to ensure the quality of water resources is suitable for their intended uses. For, it has long been realized that other substances dissolve and/or suspended in it can affect the suitability of water for any purpose (Faniran et al., 2001). Consequently, water must be substantially free from bacterial contamination, animal waste, chemical and other physical parameters to be potable and, thus, suitable for human consumption. Thus, currently, water pollution has become a major subject of public concern the world over. Despite the large volume of water that covers the surface of the earth, only 1% is inland or fresh and easily available for human use (Bockris, 1978). In Ghana, only 30% of Ghanaians have access to safe drinking water. Over 50% of Ghanaians use naturally "unprotected" source of water (Ministry of Health, Accra). The Akwapim Ridge in the Eastern Region of Ghana is no exception. The nature of the area has made it such that the indigenous population uses surface waters such as rivers, streams, ponds and springs as their only source of potable water. The qualities of these water bodies vary naturally and widely depending on climate, season, and the geology of the local bedrock. Natural variations can have a negative impact on the suitability of water for human use, in addition to the contributions emanating from human activities like agricultural practices, which is characteristic of this part of Ghana. Not only does this phenomenon pose a problem to us all but it does not augur well for any sustainable development. These surface waters may be prone to pollution. It is, therefore, imperative to carry out an extensive baseline surface water quality assessment and management evaluation study of the Akwapim Ridge before deciding whether it is necessary to carry out monitoring or not. The present study, the first in a series, focused on the water quality assessment of the springs/streams on the Akwapim Ridge to evaluate their suitability for domestic uses. It also aimed at identifying potential sources of pollution into the springs/streams. Biological characteristics could not be assessed at this stage.