Onterris, Inc. (ONT) Business

Item 1. Business.

Since our inception in 2012, our mission has been to help clients and communities meet their environmental goals and needs. We service complex and often non-discretionary environmental needs of our diverse clients across our three business segments: Assessment, Permitting and Response; Measurement and Analysis; and Remediation and Reuse. Examples of our services include:

Our industry is highly fragmented with no single market leader. By focusing solely on environmental solutions, we believe we are uniquely positioned to become a leading platform in the environmental industry. We provide a diverse range of environmental services to our private and public sector clients across the life cycle of their needs—whether they are launching new projects, maintaining operations, decommissioning operations, rehabilitating assets, managing the impacts of climate change or responding to unexpected environmental disruption. Our integrated platform has been a catalyst for our organic growth and we have built on this platform through strategic acquisitions.

Innovation is core to our strategy. As the world’s environmental challenges grow in number, scope and complexity, increasing public pressure and ongoing regulatory changes are driving the demand for better information and advanced solutions. We prioritize innovation to enhance the quality of information provided to clients, and provide solutions tailored to clients' specific environmental needs. Examples include more accurately measuring emissions, or identifying and remediating known and emerging contaminants. Our commitment to ongoing innovation includes investing in research, development, software development, and technology—both directly and through strategic partnerships. These efforts are aimed at creating better solutions for our clients. We believe that these investments, along with our focus on geographic expansion, sales and marketing initiatives, environmental service offerings, and strategic acquisitions, will continue to distinguish us in the marketplace.

Our revenue and earnings are highly resilient. We do not rely upon any single service, product, political approach or regulatory framework. We serve a diverse set of clients across a wide variety of end markets and geographies in both the private and public sectors, with the majority of clients being in the private sector. Funding for our services is typically non-discretionary given regulatory drivers and public health concerns. As a result, our business is positioned to be less susceptible to political and economic cycles. Our client activities can occur at different times for different industries, regardless of economic cycles.

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Clients generating approximately 96% of revenue in the fiscal year ended December 31, 2024 repeated in the fiscal year ended December 31, 2025.

Our financial success is driven by both strong organic and acquisition-driven growth, and as a result, our total revenue has grown at a compounded annual growth rate of 20.4% since 2020.

Our approach has allowed us to successfully and consistently scale our business, and we believe we are well positioned to continue our trajectory and market leadership as we address the growing environmental needs of our clients and communities.

The Industry

The global environmental industry is large, growing, highly fragmented and subject to complex regulatory frameworks. Federal, state, provincial and local environmental regulations dictate compliance requirements that create demand for environmental services.

Global Environmental Industry is Large and Growing

According to the 2025 Environmental Industry Study prepared by EBI, the global environmental industry is estimated to generate approximately $1.9 trillion in revenues in 2026, with $620.0 billion concentrated in the United States. According to EBI, this $620.0 billion U.S. environmental market is expected to grow at a CAGR of approximately 4.0% per year from 2026 through 2028. EBI concludes that strong tailwinds of infrastructure funding, energy security, energy transition, and climate resilience, in addition to traditional drivers of air quality, water quality, responsible waste management, resource recovery, remediation and restoration are leading to positive growth across all environmental sectors in the global market.

Public Demands, Industrial Activity, Climate Change and Regulations Each Drive Needs for Environmental Services

Heightened public awareness and stakeholder demand for environmental responsibility and sustainability have led to a growing need for environmental services. Many companies worldwide have implemented environmental, social, and governance stewardship initiatives focused on managing potential future risks, rather than merely complying with regulations.

Steady increases in industrial activity and infrastructure investment, and the regulations underpinning these activities are also driving demand for environmental services. In addition, environmental disruptions caused by climate change or aging infrastructure further increase the need for these services. Infrastructure investments and environmental emergency responses often require substantial assessments, planning and/or permitting services in addition to environmental testing or remediation services. Testing and monitoring are typically recurring processes driven by regulations throughout the industrial production lifecycle.

Beyond current regulations, future regulatory changes may also create demand for additional or supplementary environmental services. In the United States, Canada, and Australia, the federal, state, provincial and local regulations targeting air and water quality management, waste and contaminated soil management or reductions in greenhouse gas emissions, each of which drives portions of our business, have been implemented over many decades, and are subject to change.

We anticipate that these trends will continue and will spur ongoing growth in the environmental services industry.

The Environmental Services Industry is Highly Fragmented and Complex

According to EBI, thousands of firms operate in many of the markets in which we operate. While several larger firms offer environmental services as a part of broader product portfolios, much of the industry consists of small firms that provide limited service offerings that address specific regulations and geographies. These small firms face challenges in expanding offerings or geographic reach given the technical expertise, accreditations and licenses necessary to serve a broad array of clients and industries across geographies and service lines. These dynamics create significant barriers to entry in our industry.

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As clients increasingly prioritize environmental solutions to mitigate their impact on the environment, we believe they place a high value on environmental solutions providers that offer scale, advanced technology and comprehensive service capabilities. Providers able to address the full lifecycle of environmental concerns—especially those working with companies and organizations that operate across multiple jurisdictions, with complex regulatory landscapes, and across multiple environmental media (e.g., air, water and soil)—will continue to have a competitive edge.

Segments

We provide environmental services to our clients through our integrated solutions across three business segments—Assessment, Permitting and Response, Measurement and Analysis and Remediation and Reuse.

Assessment, Permitting and Response. Our Assessment, Permitting and Response segment provides scientific advisory and consulting services to support environmental assessments, environmental emergency response and recovery, toxicology consulting and environmental audits and permits for current operations, facility upgrades, new projects, decommissioning projects and development projects. We also work closely with clients to navigate the regulatory process at the local, state, provincial and federal levels, identify the potential environmental and political impacts of their decisions and develop practical mitigation approaches, as needed. In addition to environmental toxicology and given our expertise in helping businesses plan for and respond to disruptions, our scientists and response teams have helped clients navigate their preparation for and response to emergency response situations.

We believe this segment maintains a number of competitive advantages, including:

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strong relationships with key private and public sector clients with needs for multiple environmental services, facilitating cross selling opportunities;

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a core team comprised of well-known technical experts with longstanding client relationships and significant experience across the key disciplines in the segment;

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technology, software and data management capabilities, particularly within our emergency response service line;

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our proven ability to help clients navigate regulatory, public and legal scrutiny; and

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a national reach established by having successfully assessed and permitted hundreds of projects in jurisdictions across the United States.

This segment, which is primarily based on a time and materials, or T&M, revenue model, generated approximately 37.0% of our revenue for the fiscal year ended December 31, 2025.

Measurement and Analysis. Our Measurement and Analysis segment is one of the largest providers of environmental testing and laboratory services in North America. Our highly credentialed teams test and analyze air, water and soil to determine concentrations of contaminants, as well as the toxicological impact of contaminants on flora, fauna and human health. Our offerings include source and ambient air testing and monitoring, leak detection, and advanced multi-media laboratory services, including air, soil, stormwater, wastewater and drinking water analysis.

We believe we have a variety of sustainable competitive advantages in this market, including:

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one of the most prominent air testing companies in North America with vertically integrated testing and analytical capabilities, including ultra-trace analysis;

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comprehensive laboratory network in the United States, offering a complete suite of analytical solutions for virtually all environmental projects;

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one of the most experienced providers of advanced optical gas imaging “OGI” testing used to detect hydrocarbon gas leaks; and

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our proprietary software, technologies, processes and applications, including the ability to detect air contaminants in real time at ultra-trace concentrations.

This segment, which is primarily based on a fixed price and, for out-of-scope work, a T&M revenue model, generated approximately 29.6% of our revenue for the fiscal year ended December 31, 2025.

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Remediation and Reuse. Our Remediation and Reuse segment provides clients with engineering, design, and implementation services, primarily treatment technologies that treat contaminated water and remove contaminants from soil. Our employees, including engineers, scientists and consultants, provide these services to assist our clients in designing solutions, managing products and mitigating environmental risks and liabilities at their locations. We do not own the properties or facilities at which we implement these projects or the underlying liabilities, nor do we own material amounts of the equipment used in projects.

We believe this segment’s competitive advantages include:

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advanced technologies and our owned and licensed intellectual property portfolio, such as our patented water treatment systems;

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a team with industry-leading experts and several patent-generating scientists; and

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local expertise and capabilities with respect to unique soil, sediment and water table characteristics and contamination types.

This segment, which is primarily based on a fixed price, including milestone-based fixed price contracts, and, for out-of-scope work, a T&M revenue model, generated approximately 33.4% of our revenue for the fiscal year ended December 31, 2025 primarily through project-based work.

This table illustrates a summary of our segments as of December 31, 2025:

Differentiated Technology, Processes and Applications

Advanced technology, innovative processes, and applications are key competitive advantages in the environmental services industry. Our team of industry leaders plays a vital role in driving our investments in differentiated services. As our platform of environmental service offerings expands, our experts can increasingly deploy innovative technologies that address our clients’ needs, further differentiate our services and create new barriers to entry. Our investment and development activities include real-time air quality and emissions monitoring, environmental data management and visualization software, and technologies for the removal and destruction of complex contaminant streams.

In total, our research and development team has been awarded 31 patents. Our research and development team continued to innovate in the following areas: water treatment, particularly PFAS and selenium removal, PFAS destruction, PFAS testing, foam fractionation, vapor treatment and removal, wastewater treatment, resource recovery, soil vapor sampling, capture and measurement of methane and other gaseous emissions, and enhanced biological treatment.

Strategic Acquisitions

We operate in a growing and highly fragmented market with thousands of potential acquisition targets. Given our success in identifying, executing and integrating over 70 acquisitions since our inception in 2012, we believe we can continue to selectively acquire additive businesses. We seek to acquire businesses at disciplined valuation levels that:

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are led by high quality scientists and management teams,

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expand our portfolio of services,

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provide access to differentiated technologies or processes, and

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extend our geographic coverage.

We have personnel specifically dedicated to identifying acquisition targets, exploring acquisition opportunities, negotiating terms and overseeing acquisition and post-acquisition integration. Our in-house acquisition team has established extensive relationships throughout the industry and maintains and regularly re-evaluates a pipeline of potential acquisition opportunities, largely driven by word of mouth and personal introductions. Although we did not consummate any acquisitions in 2025, acquisitions remain a core component of our long-term growth strategy.

Since January 1, 2023 we have acquired the following businesses:

(1)Business was disposed of in 2025.

Clients

We provide environmental services to clients operating in a number of sectors and industries, including but not limited to oil & gas, utilities, local, state, provincial and federal government entities, technical services including engineering, industrial manufacturing, chemicals, transportation, renewable energy generation, and telecommunications. We have long-term, and through our legacy companies, decades-old relationships. We serve a diversified client base in both the private and public sectors, with the vast majority of revenue being generated from clients in the private sector.

Our largest client represented approximately 17.8% of revenue for fiscal year ended December 31, 2025, with these revenues derived from over 285 separate projects, which included a large emergency response event. As a result of the nature of our environmental emergency response business, our Assessment, Permitting and Response segment may at times experience higher customer concentration levels based on the severity, duration and outcome of certain types of environmental emergencies for which we provide response services, as was the case in 2025 when 56.9% of our Assessment, Permitting and Response segment revenues were attributable to three customers. See Item 1A. “Risk Factors.”

For the fiscal year ended December 31, 2025, 62.1% of our revenue came from customers engaging us to provide more than one service, an increase of 8.8 percentage points from the 53.3% we generated from customers buying more than one service in the fiscal year ended December 31, 2024. We have expanded our relationships with our existing customer base with our vertically integrated business model. Our maturing client relationships coupled with our integrated structure across all our business lines has increased the level of client engagement.

Contracts

Our client contracts are fixed price, including milestone-based fixed price contracts, and T&M based. See ‘Segments’ above for a discussion of how these contracts relate to each business segment. Our client contracts vary from purchase-order based contracts utilizing standard terms and conditions to comprehensive master services agreements with terms of multiple years. In accordance with industry practice, most of our contracts, both in the private and public sector, are subject to

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termination at the discretion of the client. In such situations, our contracts typically provide for reimbursement of costs incurred and payment of fees earned through the date of termination. See Item 1A. “Risk Factors.”

Competition

We operate in a competitive and fragmented market. No single company or group of companies dominates across the entire environmental services market in which we operate. Our primary competitors are divisions of large companies, various small companies, which generally are limited to a specific service and focused on a niche market or geographic region and our clients’ own in-house resources. We believe that few, if any, of our competitors currently provide the full range of environmental solutions that we offer. Each of our segments has competitors with narrower service offerings and/or geographic breadth. Our Assessment, Permitting and Response segment competitors include the environmental divisions of ERM, Ramboll, Geosyntec, Exponent, WSP and other large engineering companies and small businesses. Our Measurement and Analysis segment competitors include the environmental divisions of SGS, TRC Companies, Eurofins, Pace Analytical and other large testing companies and small businesses. Our Remediation and Reuse segment competitors include the environmental divisions or remediation segments of Tetra Tech, AECOM, Xylem, Veolia, Mead & Hunt, and other large engineering companies and other small businesses.

We compete based on the following factors, among others: reputation, safety track record, quality, geographic reach, price, technical capabilities, access to innovative technology and breadth of services. We believe that our current capabilities position us to compete favorably in each of these factors.

The environmental services industry has significant barriers to entry which would make it difficult for new competitors to enter the market. These barriers include:

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highly technical, costly and time-consuming accreditation and licensure requirements;

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ability to deploy/services client needs across geographies;

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advanced quality and safety programs and mandated scores;

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the complex and geographically varying regulatory landscape that requires significant industry experience;

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the need to acquire or develop innovative technologies and processes that are acceptable to regulatory bodies, which in our case occurred over many years of client and regulator engagements and at significant research and development expense; and

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emphasis by large clients on size and scale, length of relationship and past service record.

Intellectual Property

We utilize a combination of intellectual property safeguards, including patents, copyrights, trademarks, trade secrets and licenses, as well as employee and third-party confidentiality agreements, to protect our intellectual property. However, we do not principally rely on any single piece of intellectual property, nor is any single piece of intellectual property material to our financial condition or results of operations.

Seasonality

Because demand for environmental services is not driven by specific or predictable patterns in one or more fiscal quarters, our business is better assessed based on yearly results. Additionally, due to the field-based nature of certain of our services, weather patterns generally impact our field-based teams’ ability to operate in the winter months. As a result, our operating results in our Measurement and Analysis segment and our Remediation and Reuse segment, experience some quarterly variability with generally lower revenues and lower earnings in the first and fourth quarters and typically we experience higher overall revenues and earnings in the second and third quarters. As we continue to grow and expand into new geographies and service lines, quarterly variability in our Measurement and Analysis and Remediation and Reuse segments may deviate from historical trends.

Human Capital Resources

As of December 31, 2025, we had approximately 3,500 employees (which includes permanent and temporary full-time and part-time personnel). Approximately 2,650 employees, or 76%, of our workforce, are based in the U.S., with the remaining employees based in Canada (approximately 730) and Australia (approximately 120). None of our facilities are covered by collective bargaining agreements.

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We invest in our employees’ success by implementing people-centric strategies focused on engagement, training and development, and retention. We strive to protect the health and safety of our people, integrating safety into our daily operations.

Employee Engagement

We believe that employee engagement is critical to fostering a positive work culture.

In late 2024, we launched a company-wide employee engagement survey designed to understand and improve our workplace culture. In early 2025, we analyzed the survey results and identified key focus areas for targeted improvement. Action plans were developed and implemented throughout the year that were designed to enhance the employee experience and strengthen our employee value proposition.

In 2025, our Chief Executive Officer held quarterly global town halls and our business segment leaders led quarterly all-hands meetings to communicate corporate initiatives, reinforce key messages, and recognize employee achievements, while also soliciting and encouraging feedback from our teams. Our monthly all-employee newsletter serves as an additional communication channel, allowing us to showcase ongoing projects, share key initiatives, and provide updates from human resources and cybersecurity.

Employee Training and Development

We are dedicated to empowering our employees by supporting skills development and investing in comprehensive training and development programs. These programs provide the essential resources our teams need to succeed and thrive. We regularly review and update our training and development programs based on employee feedback and industry advancements with a goal of improving and evolving our programs. In addition to our in-house training, we also provide various avenues for continued learning, including mentoring, on-the-job training, external training courses, and tuition reimbursement. We also encourage our employees to obtain professional licenses and certifications to stay current in their fields.

Employee Retention and Rewards

We recognize that high-potential and high-performing employees seek meaningful career growth in impactful organizations; this, in turn, helps foster a sense of belonging and supports overall employee retention. Our business managers engage directly with employees to identify career aspirations, establish goals and action plans for achieving those goals, and support professional development.

Our carefully designed and comprehensive compensation package is another key element of our talent retention strategy. We strive to maintain a fair and equitable compensation program for comparable roles, experiences, and performance, regardless of employee’s race, ethnicity, gender, sexual orientation, or other personal characteristics.

We continue to strengthen our talent retention efforts by incorporating talent retention metrics into business leaders' annual incentive plans, expanding our existing mentorship programs to facilitate knowledge transfer, offering ongoing professional development opportunities with our Montrose Leadership Excellence program and Montrose Sales Leadership Development Program, and supporting flexible work arrangements to accommodate unique situations and promote work-life balance.

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Health and Safety

The health and safety of our employees is part of our culture and supported by a dedicated team of health and safety professionals. Our health and safety management system provides the framework for our health and safety program. Aligned with globally recognized standards, it is designed to promote compliance with health and safety regulations, support risk management and drive improvement. Key pillars include management oversight, well-defined processes, and employee participation, engagement, and empowerment.

We have developed company-wide procedures designed to establish safe work practices. Employees are expected to understand and follow these procedures, while project managers assess and mitigate job hazards throughout a project’s lifecycle using a range of controls, including hazard elimination, administrative controls and personal protective equipment. Beyond our standard procedures, we are focused on proactively identifying workplace hazards and implementing controls to mitigate the associated risks.

Every Montrose employee is required to complete annual health and safety training, reinforcing our attentiveness to workplace safety. Training is tailored to each division’s work activities, better enabling employees to learn about the most relevant risks and mitigation strategies.

Beyond training, we actively engage employees in safety matters. Safety is a core topic in our company-wide town halls and business segment all-hands meetings, and employees are encouraged to start meetings with a safety moment. We share timely updates and lessons learned via email or web-based alerts, promoting a proactive safety culture. Our health and safety team meets regularly to review performance and identify areas for improvement to strengthen our health and safety management system.

Finally, all of our employees have stop-work authority and can halt any project or task if they have concerns about a safety issue, without fear of retribution.

Compliance with Federal, State/Provincial and Local Laws

Our operations subject us to environmental, health and safety laws and regulations in jurisdictions where we operate, including the United States, Canada, and Australia. Such laws and regulations relate to, among other things, the discharge of wastewater, the discharge of hazardous materials into the environment, the handling, storage, use, transport, treatment and disposal of hazardous materials and solid, hazardous and other wastes and workplace health and safety. These laws and regulations impose a variety of requirements and restrictions on some of our operations and the services we provide. The failure by us to comply with these laws and regulations could result in fines, penalties, enforcement actions, third-party claims, damage to property or natural resources and personal injury claims, requirements to investigate or cleanup property or to pay for the costs of investigation or cleanup or regulatory or judicial orders requiring corrective measures, and could negatively impact our reputation with clients. We are not aware of any pending environmental compliance or remediation matters that, in the opinion of management, are reasonably likely to have a material effect on our business, financial condition, results of operations or prospects.

A portion of our revenue is derived from working with the U.S. federal government. When working with U.S. governmental agencies and entities, we must comply with laws and regulations relating to the formation, administration and performance of contracts. Internationally, we are subject to various government laws and regulations (including the U.S. Foreign Corrupt Practices Act, or FCPA, and similar non-U.S. laws and regulations). To help promote compliance with these and other laws and regulations, our employees are sometimes required to complete tailored ethics and other compliance training relevant to their position and our operations.

Information About Our Executive Officers

Vijay Manthripragada, 49 – Mr. Manthripragada joined Montrose as our President in September 2015. In June 2016 Mr. Manthripragada also joined our Board of Directors and, since February 2016, he has served as our President and Chief Executive Officer. Before joining Montrose, Mr. Manthripragada most recently served as the Chief Executive Officer of PetCareRx, Inc., from 2013 to 2015. Prior to PetCareRx, Mr. Manthripragada was at Goldman Sachs where he held various positions from 2006 to 2013. Mr. Manthripragada received his Master of Business Administration from The Wharton School, University of Pennsylvania and his Bachelor of Science in Biology from Duke University.

Allan Dicks, 53 – Mr. Dicks has been our Chief Financial Officer since August 2016. Before joining Montrose, Mr. Dicks first served as a consultant interim Chief Financial Officer from February 2015 to April 2015 and then Chief Financial Officer from April 2015 to June 2016 of Convalo Health International, Corp., a public Canadian healthcare company. Prior to that, Mr.

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Dicks held a number of finance-focused executive positions starting in 2000, including Chief Financial Officer of Universal Services of America, Chief Financial Officer of Moark, LLC, a division of Land O’ Lakes, Inc., Vice President of Finance of White Cap Construction Supply, a division of HD Supply, and first as assistant Corporate Controller and subsequently as a division Chief Financial Officer of Dole Food Company, Inc. Mr. Dicks started his career at PricewaterhouseCoopers where he spent nine years, three of which were in the mergers and acquisitions group. Mr. Dicks received his Bachelor of Commerce and Accounting degrees from the University of the Witwatersrand in South Africa. He is a Chartered Accountant in South Africa and is a Certified Public Accountant (inactive) in the State of California.

Nasym Afsari, 43 – Ms. Afsari has been our General Counsel since November 2014 and our Secretary since August 2015. Before joining Montrose, Ms. Afsari was an attorney in the corporate practice of Paul Hastings LLP, an international law firm, from September 2007 to October 2014. At Paul Hastings, Ms. Afsari represented a variety of business entities in all aspects of corporate and business law, including domestic and cross-border mergers and acquisitions, venture capital financing, private placements and joint venture transactions. Ms. Afsari earned her Juris Doctorate from the University of California at Los Angeles and a dual Bachelor of Arts degree in Economics and Psychology from the University of California at Berkeley.

James Laws, 46 – Mr. Laws joined Montrose as our Chief Operating Officer in January 2026. Mr. Laws has 25 years of experience in the environmental industry. Prior to joining the Company, Mr. Laws served from September 2023 to January 2026 as Senior Vice President and Director of Operations for the West Environment business at AECOM, a construction engineering company, where he was responsible for a portfolio of five practices with approximately 2,500 staff members. He also served from October 2021 to August 2023 as Vice President and Director of Operations for the West Environment business at AECOM, where he was responsible for three practices, and from October 2020 to September 2021 as Vice President and Director of Operations for the Air/Environmental Health and Safety Practice at AECOM, as well as the Federal Remediation Practice from April 2021 to September 2021. Before joining AECOM, Mr. Laws held a number of positions with CH2M Hill with increasing levels of responsibility and seniority beginning in 2001. Mr. Laws holds a B.S. in Chemical Engineering from the University of Southern California.

Jose M. Revuelta, 44 – Mr. Revuelta has served as our Chief Strategy Officer since June 2017, prior to which he was our Vice President and served in several other interim executive positions with Montrose since March 2014. Prior to joining Montrose, Mr. Revuelta was a Vice President with the Infrastructure and Private Equity business of UBS Global Asset Management, a large scale global investment manager, from 2008 to 2014, where he focused on the energy, utility, transportation and environmental sectors, and a member of the Infrastructure Group in the Investment Banking division of UBS from 2006 to 2008. Mr. Revuelta previously served on the Board of Northern Star Generation. Mr. Revuelta received his Master of Business Administration from the Columbia Business School, Columbia University and a Master of Science/Bachelor of Science in Industrial Engineering from Universidad Pontificia Comillas in Madrid, Spain.

Available Information

We are subject to the information and reporting requirements of the Securities Exchange Act of 1934, as amended, or the Exchange Act, and in accordance therewith, we file reports, proxy statements and other information with the Securities and Exchange Commission, or the SEC. Our annual reports on Form 10-K, quarterly reports on Form 10-Q, current reports on Form 8-K, proxy statements and amendments to those reports filed or furnished pursuant to Section 13(a) or 15(d) of the Exchange Act are available through the investor relations section of our website, www.montrose-env.com. Reports are available on our website free of charge as soon as reasonably practicable after we electronically file them with, or furnish them to, the SEC. The information on or that can be accessed through our website is not a part of this Annual Report on Form 10-K or incorporated into any other filings we make with the SEC and the inclusion of our website address is an inactive textual reference only. In addition, the SEC maintains an Internet site that contains our reports, proxy statements and other information that we electronically file with, or furnish to, the SEC at www.sec.gov.