Sanitation, irrigation and food safety
South Africa may be sitting on the verge of a biochemical time-bomb in some of our watercourses. The good news is that we have the ability to defuse it successfully and sustainably – it becomes a question of will.
The recently released final report of the four year Water Research Commission (WRC) study examining the links between river water quality and irrigated fresh produce has raised public outcry. This comprehensive study in five provinces done by a multi-institutional team comprising four universities and the National Health Laboratory Service was led by the University of Stellenbosch. The study demonstrated unequivocally that in certain parts of our country the river pollution levels have passed a tipping point, where the watercourse’s integrity is sufficiently compromised such that it can no longer absorb the ill-effects of physical and biological pollution. Perhaps most alarmingly the study confirmed that the pathogenic (bacterial and viral) infestation in certain locations, in particular downstream of informal settlements have been found on the surfaces of irrigated fresh produce on-farm. What we have in some of these locations is the potential development of a bio-chemical timebomb in our rivers. And in the cases where irrigation water is abstracted from these sources, this represents a direct and immediate threat to food safety. It demonstrates very graphically the interconnectedness of water. If we take the Stellenbosch study site, inadequate sanitation in an informal settlement has meant that human waste has made its way into the Plankenberg River. The river system in that location is not sufficiently healthy to deal with the E.Coli. and its harmful pathogenic cousins Staphylococcus and Kliebsiella among others, as result they remain powerful in the stream in numbers , much higher than all national (Department of Water Affairs) and internationally (World Health Organisation) recommended standards. These coliform- infested waters are abstracted a little further downstream to irrigate fresh produce. The study found high levels of the pathogens on the fresh produce on-farm at harvest.
What is significant is that the study fortunately confirmed that at all sites tested there are adequate post-harvest cleaning procedures to ensure that the chain did not continue to the shop shelf or the dinner table.
The solutions are obvious. The first requires an understanding by local and provincial authorities that their decisions are as integral to the health of South Africa’s water sources as those of the custodian – the Department of Water Affairs. Failure to attend to sanitation provision and wastewater treatment at municipal level will always have negative effects on the resources, and in some cases, as drastical as we have observed at the sites in this study. The second is that these solutions are available, both through long-term as well as short term measures. The recent ‘poo wars’ in Cape Town have highlighted the desperate plight of the poor and marginalised. The WRC irrigation and food safety study has therefore demonstrated that lack of decent sanitation in these informal settlements is just a few steps away from suburbia. We have a collective responsibility to defuse the ticking timebomb, and the science is also saying that we have the technological solutions at our disposal. The key that starts this engine is the political will at local, provincial and national levels of government.
By Dhesigen Naidoo, CEO of the Water Research Commission