No information available. According to http://www.bhpbilliton.com/-/media/bhp/documents/investors/annual-reports/2016/bhpbillitonsustainabilityreportnavigator2016.pdf?la=en P13:

“This has not been identified as a relevant/material issue. As a result, it is not included in our environmental data collection systems”

Jayne Russell.....2017-02-22 16:26:16 UTC