Trevali Provides Update on Search and Dewatering Efforts at Perkoa Mine

VANCOUVER, May 12, 2022 - Trevali Mining Corp. ("Trevali" or the "Company") (TSX: TV) (BVL: TV) (OTCQX: TREVF) (Frankfurt: 4TI) provides an update on circumstances at the Perkoa Mine in Burkina Faso following the serious flooding incident on April 16, where the Company and government authorities have been working on the search efforts 24 hours per day.

The Company's overarching priority has been, and continues to be, finding the eight miners still missing at the mine. We are working 24 hours a day to dewater the mine and reach our missing colleagues and continue to work hand in hand with the Burkina Faso government, authorities and emergency services at all levels.

Despite the comprehensive efforts of the search teams, including the continued addition of extra pumping equipment during the search and de-watering process, we have yet to find the missing miners. There is a refuge chamber at a depth of approximately 570 metres which is primarily designed to provide protection from industrial hazards that workers might encounter underground, such as smoke from fire, gas emissions, fall-of-ground, and ventilation failure. We cannot be certain whether all or some of the miners managed to reach the refuge as we have had no communication with the missing since April 16.

The miners were last located at various locations below Level 520 and based on planned work patterns that day and our last contact with them, it is unlikely that they would have been together when the flooding occurred, or that all of them would have been able to make it to the refuge.

In order to safely regain access to the mine, we have to rebuild the five-kilometre-long underground access ramp and to date we have restored more than 3,800 metres using more than 25,000 tonnes of waste rock. During this work, the massive scale of the flood has become clearer. We currently estimate that more than 165 million litres of floodwater swept through the underground portion of the mine. These floodwaters caused extensive damage to ramps and access roads, as well as underground infrastructure. Approximately 38 million litres of water has been pumped out of the mine as of May 11.

All of us at Trevali are hugely grateful for the continued assistance provided by Burkinabe authorities, including enabling the imports of equipment for the search effort, and expediting air carriers able to transport heavy machinery into the country, which has greatly accelerated the dewatering and search efforts. The Company has also benefitted from the relocation of the crisis management committee to the Sanguié region near the Perkoa mine site and from the support provided by government officials in daily planning meetings. Trevali will continue to welcome support from those able to assist in the search effort. Trevali and Byrnecut, the mining contractor at Perkoa, also remain in daily communication with the families of the missing workers and we continue to offer our heartfelt support.

"The environment underground in any mine is dynamic, and our teams are working round the clock, adjusting methods and adapting to the circumstances we confront as we gain deeper access in the mine," said Ricus Grimbeek, President and CEO. "We will continue to make every effort, using all available equipment and personnel, and will continue to look for any and all opportunities to safely speed up the search operation. We acknowledge the frustration of the families and the community, and we are listening to their concerns. We are committed to locating our missing colleagues as soon as possible."

Summary of Dewatering and Mine Access Rehabilitation Efforts To-Date

The response to the flood event began on the morning of April 16 with the initiation of evacuation orders and mine rescue efforts, followed by immediate action to focus search efforts on dewatering and mine access rehabilitation to quickly gain access to lower levels of the mine.

A three-phase plan was initiated to dewater the mine. Phase One involved repurposing existing service water piping systems to support initial dewatering, sump pumping in the open pit, and establishing surface pump stations to receive water from the underground. This was quickly followed by Phase Two, which involved the rehabilitation of mine access and reconstructing the road surface to re-establish the mine's existing underground dewatering system that had been damaged by the flooding. Phase Three involved the installation of significant additional pumping and dewatering infrastructure, strainer boxes, and more than 5,000 metres of new poly pipe while simultaneously gaining access to the lower levels of the mine. In total, the multiple dewatering systems are comprised of more than 24 electric submersible and diesel pumps. A series of pumps is required in order to provide the pressure required to move the water from the lower level some 550 meters vertical to the surface.

As part of its efforts Trevali continues to source and transport additional machinery and equipment to the Perkoa Mine site, including installing pumps that arrived from Ghana by truck and from South Africa by air, expedited with the assistance of the Burkina Faso government and Air France. Other mining companies in Burkina Faso have provided support in the form of pumps and operational assistance. The National Fire Brigade has also been continually on site and has provided additional emergency response support and expertise.

Both the Company and the government are undertaking ongoing investigations into the circumstances that resulted in this flood event, and Trevali has welcomed visits from all government authorities who have requested site access. The Company fully supports an open and independent investigation and will provide any assistance that may be required.

The Company will provide further details on the progress of search activities as circumstances warrant.

Trevali is a global base-metals mining Company headquartered in Vancouver, Canada. The bulk of Trevali's revenue is generated from zinc and lead concentrate production at its three operational assets: the 90%-owned Perkoa Mine in Burkina Faso, the 90%-owned Rosh Pinah Mine in Namibia, and the wholly owned Caribou Mine in northern New Brunswick, Canada. In addition, Trevali owns the Halfmile and Stratmat Properties and the Restigouche Deposit in New Brunswick, Canada. Trevali also owns an effective 44% interest in the Gergarub Project in Namibia. The Company's growth strategy is focused on the exploration, development, operation, and optimization of properties within its portfolio, as well as other mineral assets it may acquire that fit its strategic criteria. Trevali's vision is to be a responsible, top-tier operator of long-life, low-cost mines in stable pro-mining jurisdictions. Trevali is committed to socially responsible mining, working safely, ethically, and with integrity. Integrating responsible practices into its management systems, standards, and decision-making processes is essential to ensuring everyone and every community's long-term sustainability.

The shares of Trevali are listed on the TSX (symbol TV), the OTCQX (symbol TREVF), the Lima Stock Exchange (symbol TV), and the Frankfurt Exchange (symbol 4TI). For further details on Trevali, readers are referred to the Company's website (www.trevali.com) and to Canadian regulatory filings on SEDAR at www.sedar.com.

Cautionary Note Regarding Forward-Looking Information and Statements
This news release contains "forward-looking information" within the meaning of Canadian securities legislation and "forward-looking statements" within the meaning of the United States Private Securities Litigation Reform Act of 1995 (collectively, "forward-looking statements"). Forward-looking statements are based on the beliefs, expectations and opinions of management of the Company as of the date the statement are published, and the Company assumes no obligation to update any forward-looking statement, except as required by law. In certain cases, forward-looking statements can be identified by the use of words such as "plans", "expects", "outlook", "guidance", "budget", "scheduled", "estimates", "forecasts", "intends", "anticipates" or "believes", or variations of such words and phrases or statements that certain actions, events or results "may", "could", "would", "might", "will be taken", "occur" or "be achieved" or the negative of these terms or comparable terminology. Forward-looking statements relate to future events or future performance and reflect management's expectations or beliefs regarding future events including, but not limited to, statements with respect to the search efforts at Perkoa, including the Company's plans with respect thereto, the efficacy of the Company's pumping, decline ramp rehabilitation and de-watering activities and its efforts to restore electrical power and communications at the lower levels of Perkoa, the Company's ability to effectively dewater the mine and restore access to the lower levels of Perkoa, the results of any investigation of the flooding incident, and the Company's assessment of the effect of the flooding on the safety and structural integrity of Perkoa's underground areas. By their very nature, forward-looking statements involve known and unknown risks, uncertainties and other factors which may cause the actual results, performance or achievements of the Company to be materially different from any future results, performance or achievements expressed or implied by the forward-looking statements. Such factors include, among others, risks related to the Company's search efforts and plans to remedy the impact of the flooding at the Perkoa Mine, including that such efforts and plans will not be effective or achieve their desired outcomes; dependence on key personnel; labour pool constraints; labour disputes; increased operating and capital costs; foreign currency exchange rate fluctuations; operating in foreign jurisdictions with risk of changes to governmental regulation; compliance with governmental regulations; compliance with environmental laws and regulations; maintaining ongoing social license to operate; impact of climatic conditions on the Company's mining operations; limitations inherent in our insurance coverage; litigation; and other risks of the mining industry including, without limitation, other risks and uncertainties that are more fully described in the Company's annual information form, interim and annual audited consolidated financial statements and management's discussion and analysis of those statements, all of which are filed and available for review under the Company's profile on SEDAR at www.sedar.com. Although the Company has attempted to identify important factors that could cause actual actions, events or results to differ materially from those described in forward-looking statements, there may be other factors that cause actions, events or results not to be as anticipated, estimated or intended. Trevali provides no assurance that forward-looking statements will prove to be accurate, as actual results and future events may differ from those anticipated in such statements. Accordingly, readers should not place undue reliance on forward-looking statements.

SOURCE Trevali Mining Corp.