RE:RE:New Wastewater Regs
"Ammonia: Ammonia may be present in wastewater from mining operations as a result of the use of ammonium nitrate and fuel oil (ANFO) as a blasting agent. Any ammonium nitrate spilled in preparation for blasting or left over after a blast may contribute to increased ammonia concentrations in wastewater. In addition, ammonia may occur as a decomposition product from cyanide wastes."
https://www.ec.gc.ca/lcpe-cepa/default.asp?lang=En&n=CBE3CD59-1&offset=5&toc=show#s3_3_3