A sign warning this river is dying (Photo by: Joe
A warning sign on acid rain in Canada. Environmentalists have warned that it could take millennia for North America to recover from historically high sulphur dioxide emissions. (Undated file photo; Joe Sohm/Visions of America/Universal Images Group via Getty Images)
  • Eskom just started the process to apply for new exemptions from air pollution rules, including for its Medupi power station.
  • It could take up to 2030 to install the air scrubbers that are supposed to clean up Medupi's sulphur dioxide emissions, Eskom now says.
  • So it needs permission to emit eight times as much sulphur dioxide as it is supposed to be working towards.
  • Even after 2030 Medupi should never be held to the current rules on the acid-rain precursor, Eskom says.
  • For more stories go to the Business Insider South Africa homepage.

It will take at least eight more years before it installs air scrubbers to reduce sulphur dioxide from its giant Medupi power plant, Eskom now says, and in fact that may only happen in 2030.

In the meanwhile the company would like permission to emit eight times as much sulphur dioxide – the precursor to acid rain – as it is supposed to be working towards.

And even after it starts to clean up at Medupi it still does not plan to fully comply with South Africa's air-quality rules, ever. It wants the power station to be perpetually allowed to emit double the planned limit of sulphur dioxide, until it is decommissioned after what could be a 40-year or more lifespan.

Medupi has been under active construction since 2007 and will officially cost around R150 billion to finish – though the final cost could be far higher than that.

See also: Wet coal (five years ago) and Cahora Bassa – here are all the reasons Eskom has volunteered for load shedding since 2014

A system for removing sulphur dioxide, through a process called fluid gas desulphurisation (FGD), was supposed to be installed as Medupi's various generating units were completed.

But "there have been significant delays in implementation of the project" Eskom says in documents accompanying a public participation process it launched this week, without providing any further explanation.

The public participation process is due to culminate in a "public open day" in Lephalale, near the power station, on 29 January, where Eskom hopes the community will sign off on its new emissions plan.

Under rules created specifically for newer – and supposedly cleaner – generation plants, Medupi is supposed to eventually emit only 500mg/Nm3 of sulphur dioxide; that is, 500 milligrams of sulphur dioxide per normal cubic meter of gas, a standard unit used to measure air pollution.

Under a current exemption, good until May 2025, Medupi is already allowed to instead put out seven times as much as that, 3,500mg/Nm3.

But that is not enough, Eskom now says. Instead it wants the right to emit eight times the legal limit, 4,000mg/Nm3 from next year, and for the decade after that.

Even once FGD installation is complete, it still wants Medupi to be granted the indefinite right to emit 1,000mg/Nm3 of sulphur dioxide for as long as it is operational.

Eskom also wants those limits to be measured as a monthly average rather than on a daily basis, which will mean that lower output levels during weekends and other times of low electricity demand are factored in.

Applying for such variations requires formal studies that include an atmospheric impact report. These have not yet been done, Eskom says, but will be completed and submitted to the government "during 2020". 

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