Mogale City has been ranked the worst-performing municipality in Gauteng for wastewater treatment, with all three of its treatment works rated critical in the latest Green Drop Report.

The report found that the municipality’s Green Drop score declined from 75% in 2013 to below 30% in 2025, representing the largest decline of any municipality in the province.

Areas affected by sewage pollution include the Bloubankspruit, the Crocodile River and the Cradle of Humankind World Heritage Site.

The findings follow a recent oversight inspection by Deputy Minister of Water and Sanitation Sello Seitlholo at the Percy Stewart Wastewater Treatment Works in Delporton, as well as engagements with the executive mayors of Mogale City, Rand West City and Merafong on sewage pollution and the 2025 Green Drop Report.

• Also read: Despite millions spent, Cradle sewage crisis continues

According to the report, Percy Stewart scored 30%, down from 68% in 2021, while Flip Human dropped to 30% from 64%. The Magaliesburg treatment works recorded 27%, down from 49%. The municipality also received a 0% rating for both microbiological and chemical compliance.

The PA’s Gauteng MEC for Environment, Ewan Botha, said that although operational improvements were visible at the Percy Stewart plant, treated effluent quality still did not meet national standards and the refurbishment of non-operational pump stations remained outstanding.

• Also read: Progress made at troubled Mogale wastewater treatment plants

“We acknowledge the operational improvements at the Percy Stewart plant; measured optimism cannot substitute for measurable outcomes. The situation in Mogale remains a crisis by any objective standard. We also note the deadline set for Mogale City to complete effluent-dosing measures to remove E. coli from treated wastewater in the coming months,” said Botha.

He added that the Green Drop findings should serve as a warning for Gauteng, with Mogale City representing the worst-performing municipality in the province.

Sewage infrastructure under pressure

DA Gauteng spokesperson for environment Leanne de Jager claimed that 12 of Mogale City’s 14 sewage pump stations are currently non-functional, resulting in large volumes of sewage failing to reach treatment works.

She further claimed that more than six million litres of untreated or inadequately treated effluent are discharged into the environment daily and that E. coli levels in affected rivers exceed extremely high-risk thresholds.

“This is not a municipality trending in the right direction; it is a municipality in a state of sustained environmental and public health emergency. We will continue to liaise with MEC Botha to ensure that Mogale City immediately prioritises the repair of its 12 non-functioning pump stations.”

Funding and turnaround plans

Mogale City’s head of communications, Adrian Amod, acknowledged that substantial work remains to address the challenges and said the municipality continues to engage with public and private-sector stakeholders.

“We are constantly working alongside government and private-sector stakeholders. The municipality participates in the Cradle of Humankind Management Authority, a Gauteng Provincial Government-led forum where various government, private-sector and resident stakeholders collaborate, where relevant to its core mandate, to address sewer and water-related challenges.”

• Also read: Progress at Percy Stewart, but concerns remain

Seitlholo also stressed the need for urgent intervention and greater accountability.

“We cannot allow further deterioration of our water resources. Protecting our water systems is essential not only for environmental sustainability and public health, but also for safeguarding important heritage sites such as the Cradle of Humankind. Through accountability, cooperation and decisive action, we will ensure the protection and preservation of these critical resources for future generations.”

According to Amod, resolving the wastewater challenges is expected to cost more than R150m. He said R85m has already been spent.

“While we have applied for grant funding, a further R10m has been allocated in the new financial year, subject to approval.”

He said resource constraints remain the municipality’s biggest challenge, forcing refurbishment and upgrade projects to be implemented in phases.