New ash disposal facility AT LAST

A new ash disposal facility (ADF) at Kendal Power Station is clearing the way for many more years of power generation.

A joint venture between Concor and Lubocon Civils is tackling this demanding project, which is applying environmentally compliant solutions. Concor’s project manager Pierre van Vuuren highlights that safeguarding water quality is a key priority behind the project design.

Eskom’s Kendal power station near Ogies is having its ADF expanded in this multi-faceted joint venture.

The project, says Van Vuuren, will ensure that the new ADF is environmentally compliant with South Africa’s environmental regulations. The continuous ADF will store the ash generated by Kendal until 2032.

“At the centre of the project is the lined ADF, which will ensure that there’s no contamination of groundwater,” says Van Vuuren. “The various infrastructural elements of this contract all ensure that polluted water’s kept separate from clean water and that water can be recycled to reduce consumption.”

Complex draining system

The new ADF is being constructed on a 65ha footprint adjacent to the existing ADF, which is reaching the end of its operational life. The design includes a sub-soil drainage system which allows clean groundwater to run into a clean water dam.

“An impermeable liner is placed over the sub-soil drainage system, while another drainage system is installed above the liner,” explains Van Vuuren. “The upper system allows water contaminated by ash to be channelled to the pollution control dam, from where it can be used for dust suppression.”

The clean water channelled into the dam is returned to the power station for re-use. Constructing the new ADF has also required the diversion of an existing natural stream, leading to a new 3km channel being built.

Stream diversion

“The stream diversion will withstand a once-in-100-year flood and has been lined with hand-filled gabion baskets to prevent erosion,” adds Van Vuuren. “The 30m-wide stream contains over 4 100 of these baskets, each 1m high, 1m wide and 3m long.”

120 workers + 19 months

To complete this mammoth task, about 120 workers were involved over a period of 19 months, packing 42 000 tons of gabion rock into the wire baskets. More than 2 000 Reno mattresses were also used. The project has employed hundreds of local residents and sourced extensively from local suppliers. It has also trained people in a range of construction-related activities, adding significantly to skills base