Solid waste by destination
This year our sites generated 7,630 tonnes of solid waste, 74 percent less than last year. This reduction is due to the inclusion of 6,700 tonnes of soil and pond settlings in last year's total amount, which was removed during capital project work at our Cheyenne site in Wyoming USA, and to increased recycling. Approximately 4 percent of our solid waste is classified as hazardous and is mostly waste from the manufacture of our explosives products. In addition 1,456,604 tonnes of ammonium nitrate that was unsuitable for use in explosives manufacturing was converted to fertiliser at several of our sites. This was sold to local farmers as either a nitrogen rich liquid fertiliser, or a low grade solid fertiliser.
Solid chemical waste
Our sites generated 2,134,307 tonnes of solid chemical waste this 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 307 tonnes (0.01 percent) of hazardous chemical waste was mostly generated by our North American explosives initiation system manufacturing plants. This year, 2 percent less solid chemical waste was generated.
Liquid waste by destination
Our sites generated 14,280 kL of liquid waste that was sent offsite for re-use, recycling or disposal this year, a decrease of 6 percent from 2015. This liquid waste total includes 9,417 kL of contaminated water, 4,234 kL of hazardous liquid waste and 629 kL of non-hazardous waste. Approximately 54 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. 70 percent of the hazardous waste was septic liquid or sludge (considered a bio-hazard) which was sent offsite for disposal or treatment.
Waste reduction initiatives and opportunities
Continuous improvement in reducing all types of waste and increasing recycling has resulted in several new initiatives in 2016, as well as identifying focused areas for improvement in 2017.
• At Carthage, USA, a complete redesign of the site wastewater system was initiated in 2016. This will be a 5 year project which considers all wastewaters and evaluates each stream for reduction and/or elimination. The aim of the project is to reuse wastewaters, which typically contain valuable nitrates and ammonia. In addition, solids which are currently filtered and disposed of could potentially be recovered, resulting in a reduction of hazardous waste, as well as recovery of valuable product.
• The Carthage, USA site also invested $260,000 in the purchase of a Micro-Auto Gasification System (MAGS). The MAGS will convert the organics in non-hazardous explosives contaminated waste into syngas, which will be used as fuel for the MAGS and to generate hot water. This will reduce the site’s hazardous waste by approximately 10 tonnes and save approximately $130,000 each year. It will also reduce energy use for water heating.
• At Gregory, USA, a project to reclaim explosives powders during parts cleaning and nitrate residues during acid tank cleaning reduced hazardous waste and increased production.
• Our Simsbury, USA site worked to establish processes which divert plastic wrap, bolts and metal flanges to recycling, and eliminated the use of plywood in customer shipments.
• At Wolf Lake, USA, processes were established to recycle floor sweepings and non-conforming cast boosters, reducing hazardous waste and increasing production. The opportunity to recycle paper booster canisters will also be investigated in 2017.