City's sewage treatment isn't coping

URBAN water bodies - rivers, lakes and oceans are in trouble globally.

- LESLEY GREEN, CECILIA YEJIDE OJEMAYE & OTHERS

Large sewage volumes damage the open environment, and new chemicals and pharmaceutical compounds don't break down on their own. When they are released into the open environment, they build up in living tissues all along the food chain, bringing with them multiple health risks.

The city of Cape Town is no exception. It has 300km of coastline along two bays and a peninsula, as well as multiple rivers and wetlands. The city discharges more than 40 megalitres of raw sewage directly into the Atlantic Ocean every day.

In addition, large volumes of poorly treated sewage and runoff from shack settlements enter rivers and from there into both the Atlantic and the Indian Oceans.

Over almost a decade, our multi-disciplinary team, and others, have studied contamination risks in Cape Town's oceans, rivers, aquifers and lakes. Our goal has been to bring evidence of contaminants to the attention of officials responsible for a clean environment.

Monitoring sewage levels in the city’s water bodies is essential because of the health risks posed by contaminated water to all citizens - farmers, surfers, and everybody eating fish and vegetables. Monitoring needs to be done scientifically and in a way that produces data that is trustworthy and not driven by vested interests. This is a challenge in cities where scientific findings are expected to support marketing of tourism or excellence of the political administration.