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Our Story

The challenges have changed. So have we.

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Innovation

Seeing the full system and improving it.

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Our commitments

Driving long-term value through responsible delivery.

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Explore our locations across the U.S., Canada and Australia.

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Featured Solutions

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Emergency Response

Building readiness for decisive environmental action.

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Stack Testing

Accurate, EPA-compliant stack testing for industrial facilities.

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Leak Detection

Managing fugitive emissions in complex industrial facilities.

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Contact Laboratory Services

Request a quote for advanced laboratory analysis and support.

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Our Thinking

Our Thinking Spotlight

The Onterris Outlook Report
NEW REPORT

The Onterris Outlook: Why Environmental Performance Is Business-Critical

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BRIEF

Federal Methane Rules in 2026: What Oil and Gas Operators Need to Do Now

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PERSPECTIVE

CCL 6 Is a Signal, Not a Standard. Why a Science-Forward Strategy Matters Now

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BRIEF

HON MACT Fenceline Monitoring Requirements

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Who We Are
Onterris is a global environmental solutions company partnering with organizations to solve complex challenges where environmental pressures, regulatory expectations and operational risks intersect.
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Access deep environmental expertise tailored to your industry, with solutions built for real-world conditions.
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Solutions
Prepare for escalating environmental risks with expert solutions designed to perform under pressure.
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Our Thinking
Explore briefs, perspectives and articles that turn insight into action. Discover thought leadership that informs decisions and drives impact. See the ideas shaping environmental solutions and guiding your next move.
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Cuture & Careers
Where brilliant people come together to turn environmental science into real-world progress for communities, industry and the planet.
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Cullen Flanders

Emerging Contaminants Market Leader
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Cullen brings more than 32 years of experience in environmental engineering and remediation, working across leading consulting firms and research institutions. His expertise spans in situ and ex situ remediation, site characterization, human health risk assessment, industrial water management, wastewater treatment design and oversight and AFFF transition services.