Johannesburg - There has been a delay in fitting emission control equipment at the Medupi power station, Eskom said on Wednesday.
"The delay in the retrofitting... is aligned with the delay in the commissioning of the generating units at Medupi," it said in a statement.
The parastatal said it had asked for a "postponement" on its compliance time frames relating to sulphur dioxide emissions.
Medupi was meant to be fitted with 'flue gas desulphurisation' (FGD), which is a set of technologies used to remove sulphur dioxide in power plants.
The method is part of stringent environmental regulations, which have been enacted in many countries.
"Eskom has previously communicated that Medupi is being constructed to be FGD-ready, which means emission control equipment can be fitted after the station is complete."
Air quality emissions standards
In a statement on Monday, Earthlife said that in 2010, the World Bank lent Eskom $3.75bn to build Medupi.
Among the conditions of the loan agreement was that Medupi install FGD and meet South Africa's air quality emissions standards and legislation.
"However, over the past three months... Eskom has been seeking to exempt itself... and is delaying FGD at Medupi for several years," said Earthlife co-ordinator Tristen Taylor.
"The overall effect... is that Medupi will not be bound to limits in terms of the amounts of particulate matter (PM), sulphur dioxide, oxides of nitrogen, carbon dioxide, mercury, arsenic, chromium, nickel, other heavy metals... that can be emitted."
GroundWork environmental campaigner Rico Euripidou said the pollutants Medupi could generate would affect people's health.
Asthma, pulmonary disease
"Particulate matter emitted during coal combustion generates small particles... which travel deep into the airways. This leads to asthma, decrements in lung function... and chronic obstructive pulmonary disease."
He said sulphur dioxide emitted by coal burning power plants led to inflammation and hyper-responsiveness of the airways, aggravated bronchitis, and decreased lung function.
However, Eskom said it was satisfied its application for a postponement did not contradict its commitment to sustaining operations in an environmental and responsible way.
Eskom said the FGD technology required great water resources and this was a problem.
"FGD is water intensive [it will triple the water use of Medupi], and it cannot be installed on all six units until additional water is available," it said.
"Once the FGD has been commissioned, Medupi will comply with the new plant emission standard for sulphur dioxide."
Energy and water needs
Eskom said it had a problem balancing the country's energy and water needs with environmental compliance.
"Full compliance with the national emission standards at all of Eskom’s power stations will compromise South Africa’s energy and water security.
"At the same time, such compliance would place major demands on South African water resources and produce higher waste volumes, with a small incremental benefit to the environment."
Eskom alleged that air quality research over many years had shown that the primary cause of poor air quality was at ground level and not power stations.
"Eskom has adopted a phased and prioritised approach to compliance with the emission standards," it said.
"Highest emitting stations will first have to be retrofitted with emission reduction technology."