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.
Sectors
Access deep environmental expertise tailored to your industry, with solutions built for real-world conditions.
Solutions
Prepare for escalating environmental risks with expert solutions designed to perform under pressure.
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.
Cuture & Careers
Where brilliant people come together to turn environmental science into real-world progress for communities, industry and the planet.

Temporary CEMS and FTIR Emissions Monitoring

Continuous monitoring capacity when you need it, without permanent infrastructure
Low-angle view of industrial processing towers and steel pipes beneath a bright blue sky
INTRO

Delivering real-time emissions insight for complex compliance programs

Facilities need reliable emissions data when permanent monitoring systems are unavailable, compliance schedules are active or complex gas streams require immediate insight. Onterris provides rapid, emergency deployments for temporary Continuous Emissions Monitoring Systems (CEMS) and on-site monitoring using Fourier Transform Infrared Spectroscopy (FTIR) that support compliance continuity, certification confidence and advanced multi-pollutant analysis. Our field teams deliver defensible data that helps clients maintain compliance, verify performance and make faster operational decisions.

Supporting Your Industry

Onterris supports facilities with stack testing programs that help teams document compliance, manage testing schedules and respond to complex requirements.
why it matters

Real-time emissions monitoring keeps operations moving

Facilities rely on accurate emissions data to maintain compliance, avoid reporting gaps and make operational decisions. When monitoring systems are unavailable or gas streams are complex, delays can create compliance, operational and stakeholder risk.
  • Maintain compliance during monitoring disruptions
  • Measure multiple pollutants and complex emissions streams
  • Support certification with documented quality checks
  • Reduce potential delays from laboratory turnaround
  • Verify emissions performance under real and changing conditions

Advanced emissions monitoring for confident compliance programs

Onterris supports temporary CEMS, CEMS certification and FTIR emissions analysis for facilities that need accurate data under real operating conditions. Our teams help clients bridge monitoring gaps, measure complex pollutant streams and document compliance with practical field execution.
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Our capabilities
Temporary CEMS deployment during start-up, shut-down and maintenance
Certification for continuous emissions monitoring systems
On-site FTIR specialists for complex emissions analysis
HAP, VOC and inorganic gas measurement and analysis
Control equipment efficiency testing
Source screening and emission factor development

Related Services

Field worker surveying rocky terrain with binoculars.

Environmental Permitting, Air & Water Compliance Services

Working through air, water and land permitting requirements and building compliance programs that hold up under regulatory review, across regulated industries.

Explore Related Insights

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

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The Role of Stack Testing in OGMP 2.0 Gold Standard

Applying the power of FTIR stack testing to quantify methane slip and reconcile inventories with confidence

Continuous Emissions Monitoring Systems: A Key Enabler of Permit Protection

Real-time emissions data does more than meet EPA requirements, it protects operations and strengthens compliance decisions

LNG Methane Emissions Measurement & Monitoring

Learn how direct methane measurement across LNG loading, shipping and unloading helps operators strengthen emissions data, compliance and market access.