Domestic mining operations release approximately one million tons of toxic waste into the environment every year. Most of this material is contained in tailing ponds – manufactured bodies of water containing liquid effluents or wastewater separated out during the processing of
mineral ores. Due to the technical difficulties associated with isolating the metals present in this water, reprocessing the effluents to increase mine yields is typically not done.

In most countries, mining companies are required to follow stringent environmental and rehabilitation codes to minimize environmental impacts and avoid adversely affecting human health and safety. Unfortunately, even with regulation and oversight, significant environmental impact is still a common occurrence.