Environmental guidance for your business in Northern Ireland & Scotland
If you excavate coal, metal ores or other minerals, you may expose rocks and minerals that contain sulphur. If sulphur mixes with water and oxygen it can cause groundwater to become acidic. This is called acid mine drainage (AMD).
AMD can contain highly polluting substances such as lead, zinc, iron, mercury and cadmium. It often occurs when a mine is closed because any exposed sulphur will mix with water that floods the mine once you stop pumping the water out.
Contaminated water from spoil heaps and stockpiles of crushed and waste rock can also create an acidic discharge called acid rock drainage (ARD), although the term AMD is often used to cover both.
If your business has a permit, licence or exemption you must comply with its conditions, including any conditions about surface water and groundwater. If you do not comply with conditions, you can be fined or sent to prison.
You must comply with any conditions in your mineral planning consent, including conditions about AMD and ARD. If you breach the conditions for your site you may be liable for the costs of any clean up.
You may need consent from your regulator if you discharge to the public sewer, surface water or groundwater. For further information, see our guidance on discharges to water and sewer.
View our latest videos & subscribe to our channel.