The largest Hazelwood ash pond is now bright green after being sprayed with a non-toxic dust suppressant.
The aerial spraying of Hazelwood Ash Pond 4 (HAP4) was a first for the business and will assist in mitigating dust during periods of high wind.
ENGIE Hazelwood Environment Regulation Manager, Ross Brooker, said HAP4 had continued to dry out since closure and there was a potential for strong winds to generate surface dust, particularly during the high wind months of October and November.
Brooker said the non-toxic dust suppressant called Gluon was a versatile water-borne polymer emulsion that could be sprayed onto soil surfaces to form a “veneer” or “crust”. It is resistant to wind and allows water to pass through.
“The product dries clear so a green dye was added to ensure the entire pond surface was treated,” he said. “It will also be obvious if there is damage to the crust.”
Brooker said when Hazelwood was operating, the ash ponds were covered with water from the station process to mitigate any dust. This water source is no longer available.
“The ponds are now drying out but using a water cart on HAP4 was not appropriate as the pond surface is now very soft in many sections. Therefore, aerial application was the chosen method of application,” he said.
Specialist company, Rainstorm, undertook the project. A crop dusting aircraft is normally used but because of transmission lines, a Lone Ranger helicopter with a 400 litre sludge bucket attached sprayed the product.
Some 31 000 litres of Gluon, mixed with 217 000 litres of water, was applied over the 31 ha. area taking a total flight time period of 40.5 hours. The product, widely used by large mining companies, is non-toxic and will not cause any harm to personnel or the environment.
“This treatment will last at least 12 months, taking us through to the period of rehabilitation of the ponds,” Brooker concluded.
Read the article online at: https://www.worldcoal.com/coal/25072017/dust-mitigation-initiative-at-hazelwood-coal-plant-completed/