Copper processing involves the production of metal – either in pure form or concentrates – as well as waste rock and process materials (tailings) which are sent to above-ground storage facilities.

MMG LXML’s Sepon mine uses a pipeline network to transfer water and mine tailings to a nearby storage facility.  In 2015 several leaks were detected as the tailing pipeline corroded with age. Additional testing of soil and water confirmed that there was minimal environmental impact, but the leaks were concerning to MMG, the local community and the Lao Government.

Managing pipeline integrity

Sepon began a program of replacing significant segments of the pipeline at risk of failure. The program involved thickness testing, replacement of high-priority segments, vegetation clearance and daily inspections.

Sepon has conducted repairs and improvements and installed an additional environmental containment pond and drainage bunds to further minimise potential impacts.

Next steps

The leaks were found to be a result of changed chemistry in the tailings causing faster corrosion than planned.  By early 2017, the entire pipeline was replaced, to prevent further incidents. The mine has maintained regular communication and transparent engagement with local communities and the Government.

Pictured: Managing the quality of water responsibly to comply with international and Lao guidelines prior to discharging to natural watercourses.