The impact of informal settlements on water quality

A University of Cape Town (UCT) scholar is shedding light on a growing environmental crisis – how polluted runoff from informal settlements contribute to emerging contaminant pollution in South Africa’s freshwater systems.

Emphasising the urgent need for intervention in water management policies and bringing all role players on board, Kalpana Maraj, a lecturer in chemical engineering and PhD candidate at UCT’s Future Water Institute, presented her findings at the 14th International Water Association (IWA) Water Reclamation and Reuse Conference, which took place in Cape Town.

The conference, which kicked off at the Cape Town International Convention Centre on 16 March until 20 March, was just before World Water Day on Saturday, 22 March. The day is observed to highlight the importance of ground water to the environment.

“We’re essentially sounding the alarm that this problem extends beyond one small area – it’s a domino effect that impacts larger catchments and eventually the water supply for cities like Cape Town.”

Maraj’s research is based at the Water Hub in Franschhoek, a unique research site housed in an abandoned wastewater treatment facility. It is a joint initiative between the Future Water Institute, the Western Cape Department of Local Government, Environmental Affairs and Development Planning, and various local and international funders and partners.

This distinctive location of the site provides an opportunity to study nature-based solutions rather than relying on conventional, high-tech interventions, which may not always be feasible in resource-constrained settings like South Africa.

Linking runoff from informal settlements to water pollution

Her research aims to fill a critical gap in the understanding of water contamination sources. While studies worldwide have primarily focused on wastewater treatment plants as sources of emerging contaminants, few have directly linked informal settlements to this type of pollution. “We found a lot of things – ARVs [antiretroviral drugs], TB [tuberculosis] drugs, caffeine, illegal drugs – indicating that informal settlements are a significant source of emerging contaminants,” she told delegates from across the globe.

The issue, according to Maraj, stems from a lack of sanitation infrastructure in informal settlements. “Where infrastructure does exist, much of it is dysfunctional, leaking, or broken. As a result, many residents rely on the river for their daily needs: washing clothes, running small businesses, and even defecating when no other option is available,” she said.

“We need to act now to address the resulting water quality challenges.”

One of the most concerning aspects of the study is its implications for human health. As the polluted river merges with larger water systems, the contaminants spread into broader freshwater reserves. “We’re essentially sounding the alarm that this problem extends beyond one small area – it’s a domino effect that impacts larger catchments and eventually the water supply for cities like Cape Town,” Maraj warned.

Maraj emphasised that policy makers are aware of water quality challenges but often struggle with prioritisation. While the Water Research Commission has been developing a list of priority contaminants, much of the focus remains on formal wastewater treatment plants. Her research urges policy makers to also consider informal settlements as significant contributors to water pollution.

She pointed out that rapid urbanisation is exacerbating the problem. “South Africa is experiencing increasing rates of informal settlement growth. The UN [United Nations] predicts that by 2050, three billion people globally will be living in informal settlements. We need to act now to address the resulting water quality challenges.”

Raising awareness and seeking solutions

Beyond influencing policy, Maraj hopes her research will raise awareness among local communities, municipal leaders, and farmers near the affected sites. She believes education is key to addressing the issue. “There needs to be more communication at all levels – from government to schools to everyday citizens. People often take water for granted, not realising that it originates from natural sources that we are polluting.”

She pointed out the importance of community involvement in finding solutions. “Every informal settlement is unique in terms of geography, population, and land use. The only way forward is through a collaborative approach involving governments, universities, the private sector, NGOs, and residents themselves.”

Next steps

Maraj is focused on completing her PhD while continuing her research into nature-based water treatment solutions. “I find it fascinating to explore how we can rehabilitate our freshwater systems in under-serviced and resource-limited areas,” she said. Her ultimate goal is to develop interventions that allow for water reuse, particularly for agricultural irrigation and other essential activities.

“By working together, we can create meaningful change.”

Her research builds on previous work conducted at the Water Hub, where she studied nutrient degradation in contaminated rivers. During her master’s studies, she focused on high levels of ammonia, nitrate, and phosphate in runoff from informal settlements. Now, her PhD research expands on this by investigating the presence of emerging contaminants, such as ARVs, TB medications, caffeine, illegal drugs, antihistamines, and anti-inflammatory drugs in surface water systems.

Maraj knew from an early age that she wanted to pursue chemical engineering. “I found the field fascinating since early years in high school,” she said. Her career path was cemented through vacation work and job shadowing opportunities. After completing her undergraduate and master’s degrees at UCT, she spent two years working in the field before returning to pursue her PhD and to work as a lecturer.

With increasing urbanisation and water scarcity, the need for sustainable, community-driven solutions has never been more critical. “This is just step one in a long process,” she concluded. “But by working together, we can create meaningful change.”