8 November 2022
Another tailings dam failure: the Williamson Mine in Tanzania
I’m sad to report this morning that there has been yet another significant tailings dam failure, this time at the Williamson Mine in Tanzania (the location is -3.525, 33.620). There are brief reports in a number of mining related journals, including African Mining Review and Mining Weekly The reports indicate that the eastern wall of the tailings storage facility has been breached.
This is a Google Earth image of the site, which is a diamond mine owned by Petra Diamonds (75%) and by the Government of Tanzania (25%):-
Planet Labs captured an image of the site yesterday (7 November) at 07:45 UTC. The image is partially cloudy, especially over the TSF itself, but a large plume of tailings can be seen:-
I have place the marker at the approximate position of the beach in the wall of the TSF. The plume of tailings has flowed initially to the southeast and then towards the northeast. It appears that some mine waste has entered the local rivers, but the amount in unclear. The plume is over 6 km long and has a maximum width of about 1.2 km. A very rough estimate has a surface area of the plume at about 4.7 km².
There is a Sentinel 2 image of the site, also captured yesterday:-
This provides a slightly better image of the breach in the TSF wall. As yet I can find no images of the event on the ground.
This is the second major tailings dam failure in Africa in two months, following the Jagersfontein event on 11 September 2022 in South Africa.
Interestingly, Wikipedia reports that the mine was mothballed in April 2020. The owners offered it for sale in September 2021, indicating that it was permanently closed. However, Investors’ Chronicle reported last month that production had restarted.
Planet Team (2022). Planet Application Program Interface: In Space for Life on Earth. San Francisco, CA. https://www.planet.com/