MINING SERVICES
Repairing damage caused by abandoned, contaminated mines
Latest approaches to mine-remediation planning and implementation are helping the environment and communities.
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lex Watson’s interest in abandoned mines and contaminated land began with the UK Government in the 1990s. Watson, a geochemist, completed investigations of Royal Air Force stations including Second World War bomber stations and an old nerve-gas plant in Cornwall in southwest England. The Cornwall site represented a range of problems. It had been constructed in an area subject to intense historical lead and zinc mining, with some of the old shafts used for the disposal of wastes from the nerve-gas plant when it was decommissioned and demolished. Watson became interested in abandoned sites, contaminated land and mining, and began a professional journey that would later take him to South Africa and then Sydney, Australia. In 2008, Watson joined SRK Consulting as an environmental consultant. Today, he is a principal environmental scientist at SRK, specialising in environmental management, site assessment and remedial design. Watson also has extensive experience in geochemical characterisation, mine closure, water quality and water-balance modelling. “Identification and remediation of abandoned, contaminated mines are incredibly important,” Watson says. “An abandoned mine could range from a shaft in a field from centuries ago that nobody knows about to a large, well-known project. “Governments worldwide are paying more attention to the risks of old abandoned mines. Population growth and urban sprawl in cities are exposing more people to the risks of abandoned mines. Environmental expectations are also much higher and communities are better informed, allowing them to become more involved when old mines present risks.”
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A slag-lined drain at an abandoned mine.
Abandoned mines are a timely topic. More than 600 historic and abandoned mine sites in New South Wales (NSW) are listed on the Legacy Mines Program (LMP). The LMP is a NSW Government initiative that focuses on public safety and improving the environment through remediation of abandoned mines. The NSW Government is investing more than $100 million over the next 10 years to remediate abandoned mines that represent the greatest risk to public health and safety, and the environment. Remediation works include detailed site assessments, preparation of remediation action plans and engineering design works. Other Australian states and territories are increasing their focus on historic abandoned mines. “This issue is steadily gaining momentum,” Watson says. “There’s a lot of
open dialogue between governments and industry on abandoned mines and liaison with communities. It’s an issue that mining stakeholders are passionate about fixing.” RISKS FROM HISTORIC MINES Abandoned mines can have significant risks. From a public-safety perspective, an old mine shaft covered by corroded corrugated iron could lurk in a field, unknown to the public. Some people have been badly injured after falling down unmarked mine shafts in recent years. Environmentally, some abandoned mines have leached toxic materials into surface water and groundwater on-site, and into nearby waterways. That can kill aquatic life and affect downstream communities that rely on the waterways for work or recreation. Dust blown off abandoned mine sites is another risk.
