[Image: Wikicommons]
The Klip River in Gauteng has turned into a “chemical reservoir” as the vital water source feeding into the Vaal River System finally reached critical pollution levels.
The pollution levels have become so high that they now threaten the surrounding communities and ecosystems that depend on it.
A recent environmental assessment study by researchers from the University of Johannesburg (UJ) has exposed the alarming presence of polycyclic aromatic hydrocarbons (PAHs) in the river’s sediments. These organic chemicals are linked to a great many health problems, including organ damage, developmental disorders, and cancer.
The 100-kilometre Klip River flows east along the southern edge of Soweto and passes through Lenasia, Henley-on-Klip, and Meyerton before joining the Vaal River System. The surrounding communities rely on it to sustain families, livestock, and local ecosystems. It is also used for religious practices like baptisms.
“But beneath its flowing surface lies a hidden danger: cancer-causing organic pollutants accumulating at levels high enough to potentially harm human health, animals, and aquatic life,” said UJ’s Department of Chemical Sciences researchers.
The study, led by Samuel Makobe, Dr Mathapelo Seopela, and Prof Abayneh Ambushe, analysed river sediments from nine sites along the Klip River in both wet and dry seasons. Their findings, published in Environmental Monitoring and Assessment, reveal:
- Total concentrations of PAHs in river sediments reached up to 7.41 mg/kg—far exceeding environmental safety thresholds.
- High-risk toxins peak in dry seasons when water levels are lower and increasing the exposure risks as communities rely more heavily on the river.
- Zebrafish embryos exposed to sediments suffered severe malformations, delayed hatching, and 80% mortality, signalling dire risks for aquatic life and human health.
Professor Ambushe explained that PAHs are widely recognised for their “persistence and harmful effects”. These compounds primarily originate from sources like oil spills, industrial runoff, and leaking fuel tanks. PAHs are also produced during the combustion of coal, waste, and biomass – a common occurrence in urban and informal communities, especially those located near bodies of water.
“These toxins don’t just vanish… they linger in sediments, enter the food chain, and accumulate in humans and animals over time.”
As per BusinessTech, a recent toxicity investigation into zebrafish embryo development found that heart abnormalities and spinal deformities manifested within just a few days of exposure. The UJ experts explained that zebrafish possess roughly 70% of the same genetic and physiological characteristics as humans – implying that humans exposed to environments tainted with PAHs may experience comparable developmental and cardiovascular issues.
“This is a public health crisis in slow motion.”
“The problem is systemic urbanisation, inadequate waste management, and historical pollution have turned the Klip River into a chemical reservoir,” said Seopela.
It’s gotten so bad that last year, efforts to enlist a private company to recover the body of a seven-year-old boy who drowned in the Klip River were thwarted when police prohibited private divers from entering the “contaminated” water.
“If these toxins can devastate aquatic life so quickly, imagine their long-term impact on humans,” said Makobe. “The study isn’t just exposing the Klip River’s pollution crisis, but the research is leading the charge for solutions,” added Ambushe.
“By integrating advanced chemical analysis with bioassays, the research team pinpoints seasonal pollution hotspots for targeted cleanup, advocating for stricter industrial regulations, and empowering communities with data to demand safer water policies.”
Seopela told the SABC that “it would be good for the Department of Water Affairs and the Department of Environment to start looking at how we are doing with environmental monitoring.”
Despite numerous calls for urgent intervention, the Klip River continues to face severe pollution from mining activities, industrial and urban runoff, and failing wastewater treatment.
In July 2023, WaterCAN filed a criminal complaint against the City of Johannesburg and its former managers over the ongoing pollution of the Klip River caused by two leaking wastewater treatment works (WWTW). The Goudkoppies plant in Riversdale and the nearby Bushkoppies plants in Eldorado Park are both leaking untreated sewage into local water sources.
A frustrated Executive manager of water rights advocacy group WaterCAN, Dr Ferrial Adam, told BusinessTech, “The wheels of justice turn very, very slowly in this country. Sadly, this is just one example of the many dangerously polluted water sources across the country.”
[SourceL BusinessTech]
