SA’s wastewater crisis: Leaks, pollution, and the urgent need for reform

Key topics:

• Millions of litres of sewage leak daily before reaching treatment plants

• Leaking wastewater severely pollutes rivers, threatening health and ecosystems

• South Africa’s monitoring system lacks data on uncollected, untreated sewage

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By Nicholas B. Pattinson and Mark Graham*

Wastewater is the water we flush down our toilets, send down the drain from our showers and sinks or discharge from factories. It’s supposed to travel through intact pipes to be cleaned at wastewater works. If it gets into rivers and streams, it pollutes and contaminates these with nutrients, antibiotics, antiretrovirals, heavy metals, plastics, and pesticides. It can cause a full-scale ecological collapse by polluting freshwater so badly that life in the system is wiped out.

As populations grow, it’s vital for governments to monitor wastewater closely. In South Africa, the government initiated the Green Drop assessment programme in 2008 to report on all the wastewater treatment works. But the programme only ran for five years before stopping for eight years. It was eventually relaunched in 2021. What happened in those missing eight years? Aquatic ecologist Mark Graham, research scientist Nicholas B. Pattinson and water and sanitation engineer Dave Still found that tens of millions of litres of sewage went missing through leaks. They tell The Conversation Africa more about their research.

What’s the big problem with wastewater?

Less and less wastewater is being treated in South Africa even though the population is growing. Our data shows that the volume of wastewater reaching South Africa’s treatment plants did not grow from 2013 to 2021, even though the South African population increased by about 5.52 million people (10%) during that period.

This means the wastewater is going missing somewhere en route to the wastewater treatment works. Even where treatment capacity is increased or treatment plants are upgraded, this will be ineffectual if wastewater does not reach the wastewater treatment works.

As part of our larger investigations, we conducted a case study on the Darvill wastewater treatment works in Pietermaritzburg, an inland city that is capital of the second most populous province in South Africa, KwaZulu-Natal.

Over a billion rand (US$56 million) was spent upgrading the Darvill plant between 2013 and 2021 precisely so that it could treat more wastewater. However, as our data shows, the extra wastewater is not reaching the works. Darvill is treating less sewage today than it was in 2013. This is based on a prediction of how much sewage an increased population generates.

Based on the Darvill plant’s data, we calculated that 20 million litres of sewage are going missing every day before reaching the sewage works through broken pipes and failing, vandalised, and poorly maintained reticulation infrastructure.

This shows that Green Drop reporting on wastewater has huge gaps. The Green Drop report captures how well wastewater is treated but does not reveal anything about how much sewage actually reaches treatment plants. A wastewater treatment works can still score highly even if much of the sewage generated in its catchment spills directly into streams and rivers.

Pietermaritzburg is by no means unusual in this regard. For example, the Johannesburg Northern Works processed 18% less sewage (77.7 million litres per day less) in 2021 than in 2013, but its Green Drop score remained little changed.

Why is missing wastewater such a big problem?

It’s a huge problem because scientists know where it is going – straight into our streams and rivers! We see clear evidence of this in E. coli (bacteria) monitoring data within the local rivers and streams. An abundance of E. coli in freshwater systems is a strong indicator of sewage pollution. The median E. coli counts in the streams and rivers around Pietermaritzburg are typically more than ten times higher than they were 15 years ago.

Data gaps, missing wastewater, and poor wastewater management matter because they put people’s wellbeing – especially that of vulnerable and marginalised groups – and the environment at risk. Every year around the world, about 1.5 million people, including about 400,000 children under five years old, die because of poor water, sanitation and hygiene.

Secondly, it decreases water security. South Africa is already extremely water stressed. Poor wastewater management makes wastewater harder to treat and discharge safely, harder to re-purpose for other uses like irrigation, and harder to treat to recycle for drinking. It also contaminates high-quality water sources like the dams used to supply drinking water, making clean water scarcer.

And thirdly, apart from causing loss of human life, wastewater problems have substantial socio-economic implications. For example, the public healthcare system is burdened by dealing with wastewater-related diseases, such as cholera, dysentery, typhoid, and intestinal worm infections.

There are also opportunity costs related to work missed while sick. Treating water sources that should be clean but are contaminated by wastewater carries an unecessary cost too.

What needs to happen next

Several remediation efforts are needed:

• South Africa needs to invest in improving the condition and the performance of sewer networks and sewage pump stations. The capacity and performance of wastewater treatment works is almost irrelevant if sewage does not reach them in the first place.

• The governance of these sewage treatment systems must be overhauled. Our research highlights that municipal managers need to be held accountable for the whole wastewater system. This includes the reticulation (capturing wastewater and transporting it to the treatment works), treatment, and general wastewater management.

• Reinstating the Green Drop assessments was a vital step towards addressing the wastewater crisis in South Africa. It has meant that scientists and authorities are getting some data. But the Green Drop reports still do not accurately monitor how much wastewater is produced in different areas and whether reticulation networks are fit to transport all the wastewater produced.

• Our study clearly indicates the need for much stronger monitoring of wastewater reticulation. Citizen scientists can help with monitoring by using tools that monitor water quality and assess water clarity. They can also conduct simple water tests and flag potential issues to report to water authorities. Community involvement via citizen science monitoring also helps with environmental education and awareness of the importance of clean water.

• Allowing wastewater to contaminate freshwater sources led to catastrophic incidents like the 2022 Rooiwal Hammanskraal and 2014 Bloemhof cholera outbreaks. In both cases, it is likely that wastewater mismanagement led to multiple deaths. The turnaround of the wastewater crisis needs significant political will and leadership.

The efforts will be worth it. Improved wastewater management will save money, enhance water security, and improve the health of South Africa’s people and freshwater ecosystems. Wastewater must get the attention and resources it needs to avoid more disasters.

(Water and sanitation engineer David Still co-authored this article. He is also the director of engineering company Partners in Development, and chair of the Duzi uMngeni Conservation Trust.)

*Nicholas B. Pattinson works for GroundTruth and *Mark Graham works for and owns shares in GroundTruth - environment and engineering consultants.

*This article was originally published by The Conversation and has been republished with permission.