Water pollution occurs when foreign substances enter water bodies, such as dams and rivers, and degrade the quality of the water (World Wide Fund for Nature). What makes the impact of the pollution even worse, is that these contaminants can seep into the groundwater below.
All South Africans will agree that our dams and rivers are in an awful state. Droughts, pollution and mismanagement have put us in a dire situation, where we see no immediate light at the end of the tunnel.
The importance of clean rivers cannot be emphasised enough. These water bodies stretch through kilometres of urban and rural areas, where they are massively impacted by the addition of various pollutants. Rivers then carry these pollutants to the communities and ecosystems downstream, where the impact will also be reflected over time. The impact will eventually spread even further into our oceans. It truly is a disastrous ‘domino effect’.
South Africa has reached a state where no river can be considered free from pollutants. This can have a great negative impact on the health of our communities and natural ecosystems. Water, in general, is a scarce resource in North West. This province is greatly affected by river pollution, as it is downstream from the Vaal and Crocodile River (SABC, 2021), which means that North West is on the receiving end of various pollutants travelling by river from Gauteng.
Associated health risks
Without water life will not be possible. This is a common scientific fact. All living organisms require water to survive. What happens to our health when we consume polluted water?
Polluted water is often associated with poor sanitary conditions. Communities exposed to these conditions are often plagued by transmissible diseases such as diarrhoea, cholera, hepatitis A and typhoid. Diarrhoea, as a result of polluted drinking water, claims the lives of over 800 000 individuals every year on a global scale (World Health Organisation, 2019). All of the above-mentioned diseases could have easily been prevented through better water resource management and pollution prevention.
Causes
In order to address the issue of polluted water resources, we must first identify the main causes of pollution in this regard. There are various urban and rural role-players in the pollution of our rivers and dams.
Urbanisation is a growing global occurrence. Cities and towns are the sources of chemical pollutants, sewage and litter that end up in our rivers. Large volumes of litter from cities and towns end up in rivers through stormwater channels and surface runoff.
Agriculture is also guilty in this case. The ploughing and overgrazing of farmlands loosen the top-soil layer and increase the amount of soil that washes into nearby streams and dams during rainfall events and/or irrigation periods. This increases the concentration of salts and minerals in the receiving waterbody and gives it a murky appearance.
Traces of agricultural fertilisers are also found in many waterbodies, and this results in an increase of nitrate and phosphate concentrations. These nutrients enhance the growth of algal blooms and when these plants die, they are broken down by bacteria.
The bacteria require oxygen to perform this task, which eventually leads to lowered oxygen levels within the water. This phenomenon is known as eutrophication and results in the death of various aquatic organisms, including fish, due to oxygen deficiency (Rand Water, n.d.).
Deforestation is a term used to describe the clearing of natural vegetation to make space for agricultural activities and urban development. Land that is stripped of its natural vegetation is more prone to soil erosion.
As already described above, nearby streams and dams will become murky due to the addition of the eroded soil. These particles can block the gills of fish, prevent the aquatic plants on the waterbed to photosynthesise efficiently, and increase the spread of bacteria and viruses that use the suspended soil particles as a mode of transportation.
Another key cause of polluted dams and rivers that is often overlooked, is the destruction of wetlands. Wetlands act as natural ‘filters’ that store and degrade many pollutants such as phosphorus and heavy metals (Rand Water, n.d.).
Pollutants originating from industries and mining activities are responsible for some of the most devastating impacts on South African water resources. When industrial and/or mining waste is pumped into a river, it may change the pH level of the water, increase the nutrient balance resulting in eutrophication, alter the natural water temperature and cause an imbalance in natural mineral concentrations.
All these changes in water properties lead to the death of various sensitive aquatic organisms and can sometimes also lead to the death of terrestrial organisms (including humans) when consumed.
What can we do?
South Africa has various laws and regulations in place to deter water pollution, but the issue will persist until every South African realises his or her responsibility.
- Communities can start river clean-up projects, but this will not address the root cause of the issue, which is our attitude towards water. Humans tend to struggle to have a broader perspective on their impacts with regards to the environment. Industries and communities alike have this false perspective that they can easily get rid of waste by just dumping it into a river.
- Municipalities need to drastically address the issue of deteriorating sewage treatment plants. Littering and the illegal dumping of waste need to stop.
- Fisherman should make sure that they don’t leave any fishing lines or domestic waste behind when they leave a fishing spot.
- Producers should keep their livestock away from rivers, as the soil erosion and faeces that are linked to livestock farming will degrade the water quality.
The bottom line is that all people need to respect water resources by keeping them clean.
References
- Rand Water, n.d. Causes of water pollution. www.waterwise.co.za/site/water/environment/causes-of-water-pollution.html [15 September 2021]
- SABC, 2021. Experts warn poor water quality, erratic supply pose significant threat to North West economy. www.sabcnews.com/sabcnews/experts-warn-poor-water-quality-erratic-supply-pose-significant-economic-threat-in-north-west [14 September 2021]
- World Health Organisation (WHO), 2019. Drinking water. https://www.who.int/news-room/fact-sheets/detail/drinking-water [15 September 2021]
- WWF, n.d. Water pollution. https://wwf.panda.org/discover/knowledge_hub/teacher_resources/webfieldtrips/water_pollution/ [14 September 2021]