Solid waste by destination
This year our sites generated 6,611 tonnes of solid waste, 0.5 percent more than last year. 21 percent of this waste, 1,377 tonnes, was sent for recycling. This decrease is mostly due to decreases in non-hazardous contaminated wastes in our Americas business. As shown in the graph to the right, our global waste to landfill has declined since reduction targets were introduced in 2014. In 2018, approximately 2.4 percent of our solid waste was classified as hazardous and is mostly waste from the manufacture of our explosives products. In the Americas, 18,087 tonnes of ammonium nitrate that was unsuitable for use in explosives manufacturing was converted to fertiliser and sold to local farmers as either a nitrogen rich liquid fertiliser, or a low grade solid fertiliser. In Australia, 3,792 tonnes was recycled into making explosives emulsions.
Solid chemical waste
Our sites generated 2,307,510 tonnes of solid chemical waste this year, an increase of 3.7 percent from last year. Over 99 percent of this was phosphogypsum chemical waste that was stockpiled at our site in Phosphate Hill, Queensland, Australia. This waste is considered hazardous because of its low pH, however water and phosphate are currently being reclaimed from this material and it is planned that these stockpiles will ultimately be capped and re-vegetated. The other 502 tonnes (0.02 percent) of hazardous chemical waste was mostly generated during explosives initiation system manufacturing.
Liquid waste by destination
Our sites generated 19,575 kL of liquid waste that was sent offsite for re-use, recycling or disposal this year, an increase of 22 percent from last year. This increase was due to greater rainfall in Australia, which increased the volumes of nitrogen rich (contaminated) water captured on sites, and an increase in septic pump outs during the year. This liquid waste total includes 11,181 kL of contaminated water, 7,546 kL of hazardous liquid waste and 848 kL of non-hazardous waste. Approximately 51 percent of the total liquid waste was nitrogen-rich water from our fertiliser manufacturing and distribution sites in Australia that was sent offsite to third parties for use as fertiliser and/or woodchip additive. 95 percent of the hazardous liquid waste was septic liquid or sludge (considered a bio-hazard) which was sent offsite for disposal or treatment.
2018 Waste reduction initiatives
• At Carthage, USA, a 5 year project begun in 2016 to completely redesign the site wastewater system has progressed as scheduled with design alternatives and cost analyses planned for completion in early 2019. The project is considering all wastewaters and evaluating each stream for reduction, elimination or reuse to reclaim valuable ammonia and nitrates. During 2018, evaluation of solids recovery in the Cast Booster plant was completed, followed by the redesign of the filtration systems to allow solids to be recaptured for product manufacturing. This resulted in a reduction of approximately 2 tonnes of hazardous waste in 2018.
• The $260,000 Micro-Auto Gasification System (MAGS) purchased last year at our Carthage, USA site reduced solid waste by 9 tonnes in 2018. The MAGS converts the organics in non-hazardous explosives contaminated waste into syngas, which is used as fuel for the MAGS and to generate hot water, saving approximately $130,000 in waste disposal costs and reducing energy costs.
• At Simsbury, USA, the switch was made from ordering new drums with tops to ordering reconditioned drums without tops, as the tops were previously discarded. This has resulted in an ongoing reduction of half a tonne of metal waste each year and cost savings of over $5000.
• At Wolf Lake, USA, the recycling of pentolite floor sweepings has reduced hazardous waste and saved an estimated $46,000 in 2018. Paper cannister recycling was also implemented this year with both waste and cost reductions expected in 2019.