30 November
2022
FOR IMMEDIATE RELEASE |
LSE:
PDL |
Petra Diamonds Limited
(“Petra”) or the
(“Company”)
Update regarding
Tailings Storage Facility (TSF) wall breach at Williamson in
Tanzania
In follow up to its announcement of 10
November 2022, Petra provides a further update regarding the
TSF wall breach at the Williamson mine on 7
November 2022.
Impact on the environment and local
community
The assessment team has concluded there is a low risk of further
breaches of the TSF or a breach of the New Alamasi water dam.
Williamson Diamonds Limited (WDL) has constructed an initial
6m high wall to close the breached
wall area. As a precautionary measure, WDL has also constructed
containment walls upstream and downstream of the New Alamasi water
dam, while buttressing of the New Alamasi water dam wall is
underway. Various diversion trenches are also being constructed to
prevent any build-up of water and to enable rainwater to flow into
the surrounding rivers and streams.
A total of 12.8 million cubic metres of water and tailings
material were released from the TSF as a result of the breach. A
total area of 3.57km2 is covered with this material on Williamson’s
mine lease area with 1.52km2 outside the mine lease area.
Environmental work to date confirms the tailings material which
flowed out of the TSF is inert. Water and tailings material samples
were taken by the Tanzanian Government Chemist Laboratory
Authority, which confirmed that no dangerous chemicals were found
and that all chemicals were within normal parameters. This was
confirmed by separate, private, laboratory tests. Analysis is
underway with the assistance of independent experts to ascertain
appropriate measures for the clean-up or remediation of affected
areas.
Petra reconfirms that no fatalities or serious injuries occurred
as a result of the incident. A temporary rehousing scheme is being
planned for the families affected by the breach. Interim
accommodation and humanitarian relief, including psycho-social
assistance, continues to be provided to those affected. Valuation,
land and socio-economic surveys are being implemented with all the
necessary approvals from the Government.
A socio-economic study, supported by an external social impact
specialist, is well advanced to determine socio-economic impacts.
WDL, along with local, Regional and National authorities, continues
its extensive engagements with local communities to ensure that key
stakeholders are kept informed of WDL’s response, including planned
remediation activities. WDL and Petra remain appreciative of the
continued cooperation and assistance provided by Government,
community leadership and affected parties.
Technical and Production
Following the visit of a technical team that included
independent external specialists, the preliminary assessment
concluded that the failure mechanism was subsidence of a portion of
the East wall of the TSF by around 1.5m that enabled the water to crest the wall,
initiating the breach. The root cause of the subsidence has not
been determined and will require a forensic geotechnical
investigation to be completed. This work will be undertaken by an
independent company specialising in tailings dam design and
management. Cost and timing of the investigation will be available
after a detailed scoping process is completed, but initial
indications are that this exercise will take between 6 and 12
months.
In light of the failure of the existing facility, the design of
the new TSF is currently under review. This is only expected to be
finalised in February 2023, which
will determine the additional construction work required to make
the facility operational. It is now expected that this new TSF will
take longer than initially anticipated to become operable. In
parallel, a further potential option of repairing and using the
existing TSF is also being explored as a long-term solution, but
this is subject to the outcome of the geotechnical investigation.
Updates on the progress of these potential long-term solutions will
be provided in due course.
As a result of the additional work required to progress these
long-term solutions, interim deposition options are being developed
that may enable the Williamson mine to resume production around the
middle of 2023. These interim options may include utilising a
portion of the existing or new TSF. The Williamson mine will not
resume any deposition under these interim options until it has been
confirmed that it is safe to do so and any necessary regulatory
approvals have been obtained. Further work is being conducted
between WDL, Petra’s technical team and external specialists to
determine the best possible options to recommence production safely
and as soon as possible. As previously stated, accelerated waste
stripping and planned maintenance activities will continue in order
to minimise the impact of lost production. This interim plan will
be adjusted as we progress the interim options referred to
above.
WDL is considering additional financing options to provide
support during this period and is engaging with the Government of
Tanzania regarding the sale of the
previously blocked and confiscated diamond parcel, the proceeds of
which the Government of Tanzania
has agreed to allocate to WDL under the Framework Agreement entered
into in December 2021.
Further updates will be provided in due course.
Petra currently has a 75% shareholding in WDL, with the
Government of Tanzania owning the
remaining 25%.
This announcement includes inside information as defined in
Article 7 of the UK Market Abuse Regulation No. 596/2014 and is
being released on behalf of Petra by the Company Secretary.
~ Ends ~
For further information, please
contact:
Petra Diamonds,
London
Telephone: +44 20 7494 8203
Patrick
Pittaway
investorrelations@petradiamonds.com
Julia Stone
About Petra Diamonds Limited
Petra Diamonds is a leading independent diamond mining group and
a supplier of gem quality rough diamonds to the international
market. The Group’s portfolio incorporates interests in three
underground mines in South Africa
(Finsch, Cullinan Mine and Koffiefontein) and one open pit mine in
Tanzania (Williamson).
Petra's strategy is to focus on value rather than volume
production by optimising recoveries from its high-quality asset
base in order to maximise their efficiency and profitability. The
Group has a significant resource base which supports the potential
for long-life operations.
Petra strives to conduct all operations according to the highest
ethical standards and only operates in countries which are members
of the Kimberley Process. The Group aims to generate tangible value
for each of its stakeholders, thereby contributing to the
socio-economic development of its host countries and supporting
long-term sustainable operations to the benefit of its employees,
partners and communities.
Petra is quoted with a premium listing on the Main Market of the
London Stock Exchange under the ticker 'PDL'. The Group’s loan
notes due in 2026 are listed on the Irish Stock Exchange and
admitted to trading on the Global Exchange Market. For more
information, visit www.petradiamonds.com.