28 October 2022

Dr Dalu, who has experience in aquatic ecology, environmental quality monitoring, biodiversity and conservation, says creating a global science-policy interface platform should be a priority to ensure minimal to zero-emission of emerging contaminants to protect the health of freshwater ecosystems. 

Q: What are the dangers of emerging freshwater pollutants and how could this problem be dealt with?

At present, there is little mention of emerging contaminants in regulations on water and the environment, as they are not considered priority pollutants.

This has the spinoff effect that monitoring of wastewater and drinking water excludes these contaminants from testing, even though the technology exists. Generally, water quality monitoring and standards focus on a handful of basic physical and chemical parameters such as such as pH, temperature, nutrients, turbidity, faecal coliform, total coliform, Escherichia coli (E. coli) E. coli and Enterococci.

Even if the technology exists, it is costly and time consuming to test and remove a wide range of these complex emerging pollutant compounds. Conventional wastewater treatment techniques are not up to the task, although advanced techniques, such as membrane filtration, nano-osmosis, reverse osmosis and ultrafiltration technologies, can remove, at least partially remove the chemical active compounds.

Q: In cases where problems are caused by chemicals used by illegal miners to process their minerals, what should be done to clean up the water?

With cyanide, it generally does not persist when released into water or soil and will not be likely to accumulate in aquatic lifeenvironment, below a certain threshold concentration. At this point, the test results as they have been presented have not indicated the concentrations of cyanide found in the water samples tested.

That aside however, cyanide rapidly evaporates and is easily broken down by microbes within the natural environment. However, measures must be put in place to stop the illegal mining which is the main source of the chemicals within the natural environment. This suggesting that all stakeholders need to come together to stop this rampant illegal mining.

Q: The Mpumalanga Department of Water Affairs recently released a Blue Drop test result, which indicated that the province has unclean water; can you elaborate?

The main problem emanates from lack of monitoring and evaluation of our natural environment. We strongly need more men and women on the ground that will be able to pinpoint the point-source pollution as it occurs.

The fines or penalties for environmental pollution need to be substantial high enough to deter would be offenders and should be given consistently supported by efficient enforcement.

Furthermore, policies and regulations also need to go beyond the water sector to tackle the source of pollution. Measures are needed to ensure the clean, safe, and sustainable production, use and disposal of all chemicals in line with SDG’s.

Currently, the province will need millions if not billions to rehabilitate its natural environment. It is obvious that clear, up to date and enforceable policies and regulations are urgently needed to control the masses number of chemicals polluting our water today and prevent the new generation ofemerging chemical pollutants from adding to these in the future.

Thus, a lack of bi-directional communication between scientists and legislators has contributed to the dominance of chemical-by-chemical approaches and, in some cases, the relaxation of environmental regulations to profit polluting industries.

Q: South Africa is facing a serious looming water shortage and the little water we have is being contaminated. How do we avert this crisis?

The water crisis is considered to be mainly due to climate change where South Africa is projected to face physical scarcity by 2050 and also in large part due to a turn away from management based on science and risk assessment towards a more populist approach. With the little water we have, we are currently facing a serious threat from urban, agricultural, and industrial or mining pollution.

With regards to pollution, we need to have proper monitoring so that we can identify the perpetrators and, in some instances, these are known, however, the fines/penalties that they pay are not substantial enough high to deter them from further pollution.

The fines/penalties should be high such that it will make economic sense for industries to treat their wastewater before discharging it into the environment and they will also ensure that there are no leakages coming from their facilities.

Wherever possible, we need to push for pro-environmental behaviour across all sectors of South African society.

@ Story by Lisa Thabethe. Pictures supplied.