Summit Materials (SUM) Risk Analysis

The reliability and efficiency of certain of our facilities is dependent upon vital pieces of equipment, such as our cement manufacturing kilns. Although we have scheduled outages to perform maintenance on certain of our facilities, vital equipment may periodically experience unanticipated disruptions due to accidents, mechanical failures or other unanticipated events such as fires, explosions, violent weather conditions or other unexpected operational difficulties. A substantial interruption of one of our facilities could require us to make significant capital expenditures to restore operations and could disrupt our operations, raise costs, and reduce revenue and earnings in the affected locations.

Our success depends on the continuing services of key members of our management team. Our senior management team possesses valuable knowledge and skills that are crucial to our success and would be difficult to replicate or replace. While we are developing plans for key management succession and have long-term compensation plans designed to retain our senior employees, if our retention and succession plans do not operate effectively, our business could be adversely affected.

In our production and distribution processes, we consume significant amounts of electricity, diesel fuel, natural gas, liquid asphalt and other petroleum-based resources. The availability and pricing of these resources are subject to market forces that are beyond our control. For example, during 2022 the cost of coal, diesel fuel and other petroleum-based resources rose sharply. Furthermore, we are vulnerable to any reliability issues experienced by our suppliers, which also are beyond our control. Our suppliers contract separately for the purchase of such resources and our sources of supply could be interrupted should our suppliers not be able to obtain these materials due to higher demand or other factors that interrupt their availability. Variability in the supply and prices of these resources could have a material adverse effect on our financial condition, results of operations and liquidity.

We are subject to changing rules and regulations promulgated by a number of governmental and self-regulatory organizations, including the SEC, the New York Stock Exchange (the "NYSE") and the Financial Accounting Standards Board. These rules and regulations continue to evolve in scope and complexity and many new requirements have been created in response to laws enacted by Congress, making compliance more difficult and uncertain. In addition, increasingly regulators, customers, investors and employees and other stakeholders are focusing on environmental, social and governance ("ESG") matters and related disclosures. These changing rules, regulations and stakeholder expectations have resulted in, and are likely to continue to result in, increased general and administrative expenses and increased management time and attention spent complying or meeting such regulations and expectations. For example, developing and acting on initiatives within the scope of ESG and collecting, measuring, and reporting ESG related information and metrics can be costly, difficult and time consuming and is subject to evolving reporting standards, including the SEC's proposed climate-related reporting requirements, and similar proposals by other international regulatory bodies. We may also communicate certain initiatives and goals, regarding environmental matters, diversity, responsible sourcing and social investments and other ESG related matters, in our SEC filings or in other public disclosures. These initiatives and goals within the scope of ESG could be difficult and expensive to implement, the technologies needed to implement them may not be cost effective and may not advance at a sufficient pace, and we could be criticized for the accuracy, adequacy or completeness of the disclosure. Further, statements about our ESG-related initiatives and goals, and progress against these goals, may be based on standards for measuring progress that are still developing, internal controls and processes that continue to evolve, and assumptions that are subject to change in the future. In addition, we could be criticized for the scope or nature of such initiatives or goals, or for any revisions to these goals. If our ESG-related data, processes and reporting are incomplete or inaccurate, or if we fail to achieve progress with respect to our goals within the scope of ESG on a timely basis, or at all, our reputation, business, financial performance and growth could be adversely affected.

As a company conducting business with physical operations throughout the United States and Canada, we are exposed, both directly and indirectly, to the effects of changes in U.S., state and local tax rules. Taxes for financial reporting purposes and cash tax liabilities in the future may be adversely affected by changes in such tax rules. Such changes may put us at a competitive disadvantage compared to some of our major competitors, to the extent we are unable to pass the tax costs through to our customers. Organizational Structure Risks

We are subject to a variety of federal, state, provincial and local laws and regulations relating to, among other things: (i) the release or discharge of materials into the environment; (ii) the management, use, generation, treatment, processing, handling, storage, transport or disposal of hazardous materials, including the management of hazardous and non-hazardous waste used as a fuel substitute in our cement kiln in Hannibal, Missouri; (iii) the management, use, generation, treatment, processing, handling, storage, transport or disposal of non-hazardous solid waste used as a fuel substitute in our cement kiln in Davenport, Iowa; and (iv) the protection of public and employee health and safety and the environment. These laws and regulations impose strict liability in some cases without regard to negligence or fault and expose us to liability for the environmental condition of our currently or formerly owned, leased or operated facilities or third-party waste disposal sites, and may expose us to liability for the conduct of others or for our actions, even if such actions complied with all applicable laws at the time these actions were taken. In particular, we may incur remediation costs and other related expenses because our facilities were constructed and operated before the adoption of current environmental laws and the institution of compliance practices or because certain of our processes are regulated. These laws and regulations may also expose us to liability for claims of personal injury or property or natural resource damage related to alleged exposure to, or releases of, regulated or hazardous materials. The existence of contamination at properties we own, lease or operate could also result in increased operational costs or restrictions on our ability to use those properties as intended. There is an inherent risk of liability in the operation of our business, and despite our compliance efforts, we may be in noncompliance with environmental, health and safety laws and regulations from time to time. These potential liabilities or events of noncompliance could have a material adverse effect on our operations and profitability. In many instances, we must have government approvals, certificates, permits or licenses in order to conduct our business, which could require us to make significant capital, operating and maintenance expenditures to comply with environmental, health and safety laws and regulations. Our failure to obtain and maintain required approvals, certificates, permits or licenses or to comply with applicable governmental requirements could result in sanctions, including substantial fines or possible revocation of our authority to conduct some or all of our operations. Governmental requirements that affect our operations also include those relating to air and water quality, waste management, asset reclamation, the operation and closure of municipal waste and construction and demolition debris landfills, remediation of contaminated sites and worker health and safety. These requirements are complex and subject to frequent change, often in connection with changes in the presidential administration. Stricter laws and regulations, more stringent interpretations of existing laws or regulations or the future discovery of environmental conditions may impose new liabilities on us, reduce operating hours, require additional investment by us in pollution control equipment or impede our opening new or expanding existing plants or facilities. We have incurred, and may in the future incur, significant capital and operating expenditures to comply with such laws and regulations, and in some cases we have been or could be named as a defendant in litigation brought by governmental agencies or private parties. In addition, we have recorded liabilities in connection with our reclamation and landfill closure obligations, but there can be no assurances that the costs of our obligations will not exceed our estimates. The cost of complying with such laws and defending against any litigation could have a material adverse effect on our financial condition, results of operations and liquidity.

Even though the majority of our government contracts contain raw material escalators to protect us from certain input material price increases, a portion or all of the contracts are often on a fixed cost basis. The costs incurred and profit realized, if any, on our contracts can vary, sometimes substantially, from our original projections due to a variety of factors, including, but not limited to: failure to include materials or work in a bid, or the failure to estimate properly the quantities or costs needed to complete a lump sum contract; delays caused by weather conditions or otherwise failing to meet scheduled acceptance dates; contract or project modifications or conditions creating unanticipated costs that are not covered by change orders;changes in availability, proximity and costs of materials, including liquid asphalt, cement, aggregates and other construction materials (such as stone, gravel, sand and oil for asphalt paving), as well as fuel and lubricants for our equipment; to the extent not covered by contractual cost escalators, variability and inability to predict the costs of purchasing coal, diesel, natural gas, liquid asphalt and cement; failure by our suppliers, subcontractors, designers, engineers or customers to perform their obligations; mechanical problems with our machinery or equipment; difficulties in obtaining required governmental permits or approvals; changes in applicable laws and regulations; uninsured claims or demands from third parties for alleged damages arising from the design, construction or use and operation of a project of which our work is part; and public infrastructure customers may seek to impose contractual risk-shifting provisions more aggressively which may result in us facing increased risks. These factors, as well as others, may cause us to incur losses, which could have a material adverse effect on our financial condition, results of operations and liquidity.