CAPE TOWN – Water quality around Cape Town’s three sewage marine outfalls remains generally stable and within prescribed guidelines, according to the City of Cape Town’s latest monitoring results.

The City says 98.6% of 513 seawater samples collected between April and June met water quality guidelines, with seven samples recording higher-than-allowed levels of enterococci, a type of bacteria used as an indicator of faecal contamination.

The results, presented at the Permit Advisory Forum on Friday 21 August, cover monitoring around the Camps Bay, Green Point and Hout Bay marine outfalls.

The City says most of the exceedances were detected close to the outfall outlets, while only one was recorded outside the edge of the designated mixing zone at a mid-shore monitoring site.

The latest findings are broadly consistent with the results recorded over the previous two years, which the City says indicate generally stable coastal water quality around the three outfalls.

Latest results

Mayco member for water and sanitation Zahid Badroodien said the results were encouraging but warned against complacency.

“While the findings show that water quality around the marine outfalls remains largely within guideline standards, we are not complacent,” Badroodien said.

He said protecting and improving the health of Cape Town’s marine environment remained a priority, with the City continuing its monitoring programme and assessing future treatment solutions.

One instance of acute toxicity was also detected at a Camps Bay monitoring site in May, according to the City.

The City says the monitoring programme is intended to provide ongoing scientific information about the condition of coastal waters around the marine outfalls and to inform future decisions about wastewater infrastructure.

Effluent under scrutiny

The City is also continuing to test the quality of effluent discharged through the three marine outfalls.

For the April to June quarter, the City’s own grab-sample results recorded compliance with current Coastal Water Discharge limits of 88.7% at Camps Bay, 86% at Green Point and 99.4% at Hout Bay.

Independent external laboratory composite-sample results recorded higher compliance rates of 97.9% at Camps Bay, 97.2% at Green Point and 97.9% at Hout Bay.

The figures form part of the City’s ongoing reporting and monitoring obligations around the three outfalls.

Refurbishment underway

Meanwhile, the City says its programme to refurbish and strengthen the three marine outfall systems is progressing.

The refurbishment contract began on 14 January 2026, while a construction work permit covering the three outfall pump stations was issued in April. The City says equipment procurement is underway, with key mechanical and electrical equipment, including pumps, screens and washer compactors, expected to be delivered and installed.

The refurbishment forms part of the City’s medium-term plans for the systems between 2026 and 2028.

Long-term treatment

The City is also investigating alternatives to the current marine outfall system, including additional treatment processes.

It says 60 potential design options have been assessed and narrowed down to nine viable scenarios. The preferred long-term concept includes biological treatment using activated sludge bioreactors and sludge management, followed by advanced treatment aimed at addressing contaminants of emerging concern.

The feasibility study is about 85% complete, with the final report expected by the end of September.

Any long-term solution will depend on the outcome of the feasibility study, environmental authorisations and available funding.

ActionSA awaits outcome

The latest City findings come amid continued criticism from ActionSA over the use of marine outfalls. ActionSA has previously challenged the City’s compliance with permit conditions and has raised concerns about the discharge of wastewater into the ocean.

The party has also pursued regulatory and legal avenues relating to the outfalls. ActionSA said it was still awaiting an outcome in a matter lodged in 2024 concerning allegations that the City had breached environmental permit conditions and regulations.

The City, however, maintains that its marine outfalls are subject to monitoring and regulation and that coastal water quality remains generally stable.

The Department of Forestry, Fisheries and the Environment has previously confirmed that wastewater discharge into coastal waters is regulated through Coastal Waters Discharge Permits.

The City has also expanded its coastal monitoring programme to include wastewater treatment works at Mitchells Plain, Simon’s Town, Millers Point, Llandudno and Oudekraal.

The expanded monitoring is intended to assess environmental impacts associated with treated effluent discharges and compliance with recently issued Coastal Water Discharge Permits.

For residents and beach users, the City’s latest results provide reassurance that the monitored coastal waters around the three marine outfalls remain largely within the applicable water quality guidelines, while longer-term treatment options continue to be investigated.

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