Trevali Announces Mine Rehabilitation and Dewatering Progress at Perkoa Mine in Response to Flooding Event and Provides an Update on Search and Rescue Efforts

VANCOUVER, April 25, 2022 - Trevali Mining Corp. ("Trevali" or the "Company") (TSX: TV) (BVL: TV) (OTCQX: TREVF) (Frankfurt: 4TI) provides an update on search and rescue efforts for eight missing workers as well as progress made on mine rehabilitation and dewatering at the Perkoa Mine in Burkina Faso following intense rainfall that occurred in the early morning of April 16, 2022 and resulted in flooding of the mine.

Eight workers remain unaccounted for following the evacuation of the underground area of the mine and the Company is working closely with Burkinabe authorities as search and rescue efforts continue. Mining and milling operations at Perkoa will remain suspended for the foreseeable future as the Company investigates the cause of the flood event.

The Company initially reported the incident on April 16, 2022, the date of the flooding. A second release was issued April 21, 2022 to provide an update on the Company's activities in response to the flooding of the mine and convey the initial assessment of events surrounding the flood event at the Perkoa Mine. The Company today provides a further update on its activities in response to the flooding of the mine, particularly the logistical operation behind the search and rescue efforts for the missing workers, which includes mine decline rehabilitation and dewatering activities.

"Our primary focus is the search for our colleagues and to do this we are getting pumping and other dewatering equipment where it is most needed," said Ricus Grimbeek, President and CEO. "The flood eroded the decline ramp that is the primary access to all levels of the mine and repairing this access ramp for safe use was a critical initial step in our efforts. With the completion of the decline rehabilitation to Level 520, pumping capacity has now increased, including the installation of a new 5,000-metre pipeline to surface with multiple teams of welders dedicated to completing the assembly and installation. Trevali's senior leadership and Byrnecut, Trevali's mining contractor at the Perkoa Mine, continue to meet with the families of the missing workers and to ensure they have everything they need in these difficult times. We are grateful for the valuable support from the Burkina Faso government and the broader Burkina Faso mining community who are providing all assistance possible in our search and rescue efforts."

The Company has had regular communications with, and received assistance from, the Burkinabe Ministry of Mines and Quarries, the National Emergency Rescue, Military Civil Construction, the Governor of Central-West Region, and the High Commissioner of Réo. A delegation from the government was provided a briefing at the Perkoa Mine site on April 23. Representatives included the Minister of Mines and Quarries, the Minister of Environment, the Minister of Labour, the Minister of Religious and Cultural Activities, the Governor of Central-West Region and the President of the Chamber of Mines.

Additional updates:

• The water level in the mine has settled at approximately Level 520 (520 metres from surface). Communications and electrical power have now been re-established to Level 520.
  
  
• While most workers underground or preparing to enter the mine were able to safely evacuate, the eight missing workers were working below Level 520 at the time of the flooding and there has been no communication with these workers since soon after the evacuation order was given. There are two refuge chambers located below Level 520 that are designed to provide a refuge for workers trapped in a hazardous environment. We do not know if some or all of the eight missing workers were able to access these refuge chambers.
  
  
• The decline ramp roadway is the essential access for vehicles moving people and equipment between levels in the mine. The torrent of water entering the mine resulted in significant road surface erosion. Rehabilitation of the decline ramp is essential to allow the transport of larger pumps to Level 520 to increase dewatering capacity. The Company has completed approximately 3,643 metres of an estimated 5,000 metres of decline ramp rehabilitation the Company believes is required to gain access to lower mine levels, reaching the water level at Level 520 as of April 23.
  
  
• The Company has a three-stage dewatering plan, of which the first two stages - the repurposing of existing piping to commence initial dewatering efforts, followed by the installation of additional underground pumping infrastructure to facilitate an increase in pumping capacity - are now complete and actively pumping. The third stage, which is currently in progress, involves the installation of 5,000 metres of new piping and higher-capacity pumps to increase pumping capacity. Multiple welding crews are mobilized for this assembly effort.
  
  
• The objective of the plan is to dewater the mine to continue the search and rescue efforts for the missing colleagues while working toward completely dewatering to the lowest level of the mine. The Company has also re-established sump pumping in the open pit and doubled pumping volume capacity as a precautionary measure while we continue to investigate the cause of the event.

The Company will provide further details on progress of search and rescue activities and site investigation as more information becomes available.

About Trevali Mining Corporation

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 suspension of mining and milling operations at Perkoa, the rescue and recovery 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, the Company's assessment of the effect of the flooding on the safety and structural integrity of Perkoa's underground areas, the effect of the flooding on the cost of production at Perkoa, the length of time before underground mining operations can be recommenced safely at Perkoa and the effect of the suspension on the Company's results of operations and metal production. As well, forward looking statements relate to the Company's growth strategies, the continued success of mineral exploration, the content, cost, timing and results of future exploration programs and life of mine expectancies, Trevali's ability to fund future exploration activities, estimation of mineral reserves and mineral resources, the realization of mineral reserve estimates, the timing and amount of estimated future production, costs of production and capital expenditures, success of mining operations, environmental risks, unanticipated reclamation expenses and title disputes or claims. 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 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; actual results of current exploration activities, including the inherent uncertainty of mineral exploration and estimations of exploration targets; changes in project parameters as plans continue to be refined; future prices of zinc, lead, silver and other minerals and the anticipated sensitivity of our financial performance to such prices; possible variations in ore reserves, grade or recoveries; dependence on key personnel; potential conflicts of interest involving our directors and officers; labour pool constraints; labour disputes; availability of infrastructure required for the development of mining projects; delays or inability to obtain governmental and regulatory approvals for mining operations or financing or in the completion of development or construction activities; counterparty risks; increased operating and capital costs; foreign currency exchange rate fluctuations; operating in foreign jurisdictions with risk of changes to governmental regulation, including any new or ongoing decrees and regulations issued by any governmental authority in response to the COVID-19 pandemic; compliance with governmental regulations; compliance with environmental laws and regulations; land reclamation and mine closure obligations; challenges to title or ownership interest of our mineral properties; maintaining ongoing social license to operate; impact of climatic conditions on the Company's mining operations; corruption and bribery; limitations inherent in our insurance coverage; compliance with debt covenants; competition in the mining industry; our ability to integrate new acquisitions into our operations; cybersecurity threats; 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.