The Department of Forestry, Fisheries and the Environment’s (DFFE's) National Air Quality Officer (NAQO) has granted State-owned power utility Eskom a postponement to meet minimum emission standards (MES) at the Kusile power station, in Mpumalanga, from June 5 this year to March 31, 2025.

This postponement is subject to certain strict conditions. 

The postponement application was necessitated by the failure of Kusile's west stack on October 23 last year. The failure limited the power station’s ability to operate three commissioned generating units (units 1, 2 and 3).

These units would each provide about 700 MW to the national grid and potentially reduce loadshedding by two levels. 

Eskom’s short-term technical solution is to return the units through the construction of three temporary stacks that will bypass the flue gas delsuphurisation (FGD) plant while repairs to the affected stack are under way. The operation of these three temporary stacks will enable the return of 2 100 MW to the grid.

The NAQO, in concurrence with the Nkangala district municipality as the Atmospheric Emissions Licence authority, considered Eskom’s postponement application.

This was considered along with the impacts on health and environment and balancing this against the negative impacts of electricity supply, with NAQO determining that the application should be granted.

The application was granted, subject to certain conditions.

The first is that Eskom is required to take measures to mitigate harm caused by the exposure of sulphur dioxide (SO₂) to its employees and surrounding communities. This must include, at minimum, independent health screenings and the referral of people requiring healthcare to the appropriate public health facilities for treatment.  

Eskom is also required to submit a detailed plan on the mitigation measures it intends to put in place within 21 days of receipt of the decision. This plan will need to be approved by the NAQO and Nkangala district municipality. 

Further, Eskom is required to submit quarterly progress reports on the implementation of the compliance roadmap and commitments made towards recommencing use of the FGD plant.

In addition to these conditions, Eskom also has to meet any requirements set by the Nkangala district municipality. 

This decision may be reviewed by the NAQO with the concurrence of Nkangala district municipality during the postponement period in line with the National Environmental Management Air Quality Act provisions.

Lastly, this decision must be reflected in the Kusile atmospheric emission licence (AEL) to be of any force and effect. 

In response, Eskom welcomed the decision by the NAQO to grant the organisation a postponement in terms of the MES pertaining to the SO₂ emission levels at Kusile.

Eskom also noted and welcomed issuing an updated AEL for Kusile to reflect this postponement decision by the Nkangala district municipality. 

The postponement - granted on June 5 this year and the licences issued on June 13 - mean that Eskom will be able to operate the three units without the use of the FGD plant for the period up to March 31, 2025, while the flue gas ducts in the permanent stack are being repaired.

The FGD plant is equipped with emission-abatement technology for SO₂.

The repairs to the ducts in the permanent stack will be completed by December next year. This comes after the failure of the Unit 1 flue gas duct on October 22 last year.

The failure at Unit 1 subsequently affected units 2 and 3 as the ducts for all these three units are in the same stack (chimney).

The temporary stack structures for Unit 3 will be completed by November this year, and for Units 1 and 2 by December.

The postponement and licence is subject to several conditions, including the implementation of measures to mitigate the impact of SO₂ emissions on air quality. Eskom will comply with the conditions of the MES postponement and the AEL.

Copies of the MES decision and AEL, as well as details of the process to follow to appeal either of the documents, are available on the website of Eskom’s independent consultants Environmental Impact Management Services.