N E W S & V I E W S • D E C E M B E R 2 0 2 3 13 The devastating fire at NCT Richards Bay Wood Chip and BayFibre, starting on Saturday 30 September and burning until Thursday 12 October was not without environmental impact. The fire engulfed most of the NCT site, burning the chip piles, conveyors, stackers, the log yards, and some buildings such as the screens. A great deal of effort was placed on stopping the spread to neighbours, including TWK’s chip pile (which is some 30m away) and the nearby fertilizer plant (FOSKOR), as well as the spread into the natural area between the site and residential areas. This entailed the use of a great deal of water – 1 103 700 litres were used by aerial water bombers alone. (This was from fixed wing aircraft and helicopters). Various fire retardants were used to maximise the impact of this water. The type of retardant used was in part determined by their availability. An immediate effect of the fire was a huge plume of smoke which spread according to prevailing wind conditions. The plume of smoke was visible from a long distance and blew as far as 30 km away. While the scale and density of the plume was an issue, a redeeming feature was the fact that this was burning wood smoke with no additional chemicals added. Investigations are ongoing as to the possible effects of this smoke plume. However, circumstantial evidence suggests that the main impact was on people with respiratory ailments (Asthma, bronchitis etc). Health warnings were issued to the Richards Bay community when the wind direction carried the smoke plume into the town and surrounding suburbs. People with respiratory ailments were requested to remain indoors. Occutech (approved inspection authority) have an ongoing air quality monitoring programme in Richards Bay, they were commissioned to do air quality monitoring in and around the mill site. Their preliminary report indicates that the main risk to human health during the fire was to people close to the source (firefighters and people working on site). Tests conducted in the later days of the fire showed that the air quality levels on site were within the acceptable work standards for RSA. An unforeseen impact of the firefighting effort was contamination of adjacent water bodies by water runoff from the site. By Monday 9 October, dead fish were being found in the Richard’s Bay harbour. While the cause of these deaths was not immediately known, it was suspected that they could be linked to the fire. Ongoing Investigations will reveal more, but it can be assumed, given the nature of the deaths and the initial results of the very basic water tests, that this was attributable to the very low dissolved oxygen levels in the water. Dissolved oxygen levels are usually measured in milligrams per litre (mg/L) or parts per million (ppm). Healthy water should generally have dissolved oxygen concentrations above 6.5-8 mg/L. Dissolved oxygen levels that are too high or too low can harm aquatic life and affect water quality. Excess organic material (eg leachate from fire) in water can result in oxygendeficient situations. Different aquatic organisms have different dissolved oxygen requirements. For instance, bottom feeders need minimal amounts of oxygen (1-6 mg/L), while shallow water fish need higher levels (6-15 mg/L). Monitoring sites below runoff discharge points have indicated that dissolved oxygen levels went as low as 3,09 mg/L. Shortly after fish mortalities were noticed, various interventions were implemented at the mill to reduce runoff into adjacent water bodies. The stormwater drain from the still smouldering wattle chip pile was blocked off and bunding was erected to contain any further water drainage from the pile. The amount of water used to finally put out the smouldering pile was also severely limited. At this stage, the eucalyptus chip piles on the south side of the site had burnt out and very little water was being used here. The water flooding the screens building has been tested and is cleared for disposal into the municipal wastewater system. The hazardous-waste company, Spilltech, was contracted to remove the dead fish, and the sediment material from below the stormwater outlet as well as the polluted water collecting within the bunded area. This material was deemed to be hazardous waste and was disposed of in the appropriate manner. Teams were deployed along the canal and affected harbour area to collect dead fish. Signs were also placed at various points to warn people of the possible hazard that fish might pose and not to use them in any way.
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