The Industrial Development Corporation (IDC) has apologised for unintentionally dumping toxic chrome into the Crocodile River near Brits earlier this month.
”The IDC greatly regrets this unfortunate incident and commits itself to cooperating with the authorities to minimise the consequences,” the state development company said.
”The IDC is also committed to completing the plant demolition and site clean-up operation safely and within the shortest possible time.”
It explained that a watchman trying to turn on the floodlights at a water-treatment plant at African Chrome on the night of December 8 inadvertently switched on a set of pumps that discharged water contaminated with Chromium-6 (Cr-6) into a municipal sewage system.
”The quantity of contaminated water discharged from the African Chrome site is estimated at about 180 cubic metres. All necessary steps to avoid a recurrence of such an incident have been taken,” the IDC added.
The plant in Brits was built in 1996 to produce sodium dichromate for the local and export markets, but is now out of use and its parts are being demolished, decontaminated and sold as scrap.
The red-orange chemical commonly used in the dyeing process of textiles and leather contains Cr-6, which is toxic to the liver, kidneys and digestive system if ingested and can cause lung cancer if inhaled over a long period.
Properly released, Cr-6 breaks down into Cr-3, which is 500 times less toxic.
In this case, too much was released, resulting in water with a concentration of 41mg of Cr-6 per litre being discharged in the Crocodile River from the municipal waste water-treatment plant.
The upper limit of acceptable contamination of drinking water has been set at 0,05mg of Cr-6 a litre by the Department of Water Affairs and Forestry.
Ingesting higher concentrations can cause mouth sores, stomach aches, indigestion, diarrhoea, vomiting and a raised white-blood-cell count. Prolonged exposure may cause cancer.
The IDC pointed out that heavy rainfall and a strongly flowing river on the night in question would have diluted the bright-yellow discharge.
While no sign of contamination has been found yet in inspections and sampling of the river up to the Rooikoppies Dam and several boreholes near the river, it is possible their Cr-6 concentrations are over the recommended limit, the IDC said.
It urged caution in the use of water directly from the river, the dam or boreholes until later this week, when chemical analysis of the samples will be available.
Yellow-tinged borehole water cannot be used for drinking or even irrigation, as Cr-6 at a high concentration acts as a herbicide.
The IDC asked anyone with yellow borehole water to stop pumping and notify the IDC’s Etienne Roux on Tel: 082 774 2045.
It also urged anyone with a borehole within 250m of the Crocodile River or the Rooikoppies Dam to call Martin Steenkamp on Tel: 083 298 900 for free testing for Cr-6.
At the time of its shutdown in 1999, African Chrome’s Russian-South African owners filled the areas designed to hold spillages with materials containing Cr-6, also dumping these materials in areas where they contaminated the soil and groundwater.
The IDC immediately took control of the site and launched a clean-up of the soil and water.
The demolition and site clean-up is scheduled for completion in the middle of next year. Complete remediation of the groundwater will take at least 10 years, but does not pose any health threat to the public. — Sapa