Onterris, Inc.

Onterris, Inc. operates as an environmental services company across the United States, Australia, Canada, and other international locations. The company is structured into three segments: Assessment, Permitting and Response; Measurement and Analysis; and Remediation and Reuse. Onterris provides scientific advisory and consulting services, assisting with environmental assessments, emergency response and recovery, toxicology consulting, and environmental audits and permits for various projects including current operations, facility upgrades, new developments, and decommissioning. Its services also encompass environmental testing and laboratory analysis, such as source and ambient air testing and monitoring, leak detection, and advanced multi-media laboratory services for air, soil, stormwater, wastewater, and drinking water. Additionally, Onterris offers engineering, design, and implementation services, including treatment technologies for contaminated water or soil remediation. The company serves a diverse client base, including the oil and gas, utilities, government (local, state, provincial, and federal), technical services, industrial manufacturing, transportation, chemicals, renewable energy generation, telecommunications, and engineering industries. Founded in 2012, Onterris, Inc. changed its name from Montrose Environmental Group, Inc. in May 2026 and is headquartered in North Little Rock, Arkansas.