What is the most critical environmental issue associated with mine closure that must be addressed in an EIA?

The most critical environmental issue associated with mine closure that must be addressed in an EIA is the long-term prevention and control of acid mine drainage (AMD). AMD is the outflow of acidic water from a mining site, often containing elevated levels of heavy metals and sulfates. It forms when sulfide minerals, exposed during mining, react with water and oxygen, creating sulfuric acid. This acidic water can leach heavy metals from the surrounding rock, contaminating surface water and groundwater resources and harming aquatic life. AMD can persist for decades or even centuries after mining operations cease, posing a significant long-term environmental risk. Therefore, the EIA must include detailed plans for preventing or minimizing AMD formation during mine closure, such as isolating sulfide-bearing materials, neutralizing acidic water, and implementing long-term water treatment strategies. Failure to adequately address AMD can lead to severe and irreversible environmental damage.