Meet Our Team

Adrienne LaPierre, Principal and President

Practice Areas: Human Health Risk Assessment, Exposure Assessment, Toxicology, Risk Management, and Risk Communication

Ms. LaPierre has more than 20 years of experience in environmental consulting, with emphasis on toxicology and human health risk assessment. She has managed or performed multipathway risk assessments for Superfund sites, RCRA facilities, petroleum release sites, town gas sites, and various types of industrial properties. She has extensive experience in performing critical evaluations of the toxicological literature, defining dose-response relationships, establishing exposure limits, and evaluating potential causal associations between chemical exposures and documented adverse health effects.

Nicholas T. Loizeaux, P.G., Principal

Practice Areas: Brownfields Redevelopment, Site Investigation and Remediation, Geologic and Hydrogeologic Site Characterization, and Hazardous Materials/Waste Management

Mr. Loizeaux is a California professional geologist and has over 20 years of experience as a technical consultant in the fields of geology, hydrogeology, and contaminated site investigation and remediation. Most of this work has been conducted in the context of Superfund, due diligence compliance, litigation, or Brownfields redevelopment. Mr. Loizeaux has designed and implemented numerous site investigations, which have included hundreds of soil borings, monitoring well installations, monitoring well decommissionings, subsurface geophysical investigations, aquifer tests, and soil, groundwater, and soil gas sampling efforts. He has brought a number of underground and above-ground storage tank (UST/AST) cases to closure, brought a number of sites to closure, and has conducted numerous due diligence audits of manufacturing, agricultural, and commercial properties.

Robert B. Balas, Principal

Practice Areas: Regulatory Compliance Audits, Compliance System Development, Subsurface Fate and Transport, Emissions Estimation, Landfill Assessment, Dispersion Analysis, Proposition 65, and Exposure Analysis

As a Principal at RPS Iris Environmental, Mr. Balas specializes in analyzing chemical fate and transport in the environment to determine impacts on human health. This includes expertise in environmental regulatory compliance audits, indoor and outdoor air emissions estimation and air dispersion modeling, subsurface transport, and exposure assessment. His work has included compliance report generation, air dispersion modeling, exposure assessment, developing software for air emissions estimation, and multipathway risk assessment.

Sandra H. Stevens, Principal

Practice Areas: Brownfields Redevelopment, Site Investigation and Remediation, Environmental Compliance, Hazardous Materials/Waste Management

Ms. Stevens has over 15 years of experience in environmental management. She recently served as Associate Vice-President for Environmental Services for Catellus Development Corporation, a San Francisco Bay Area real estate developer. In this position, she directed all environmental activities for the company, including compliance with environmental laws and regulations, the regulatory approval process, due diligence requirements, remediation of contaminated properties, and community outreach and education.

Gregory S. Noblet, P.E., Principal

Practice Areas: Site Characterization, Vapor Intrusion Evaluation and Mitigation, Emissions Estimation, Dispersion Modeling, Health Risk Assessment

Mr. Noblet is a California professional engineer with more than 18 years of consulting experience, including 15 years with Iris Environmental. He has designed numerous subsurface site investigations to characterize impacts to soil, groundwater, and soil gas. He specializes in emissions estimation and dispersion modeling to evaluate impacts to offsite receptors; and in vapor intrusion assessments, where multiple lines of evidence must be considered in evaluating indoor air sampling results. He has worked with several analytical laboratories to develop helium shrouds and soil gas sampling trains compliant with the Cal/EPA Soil Gas Advisory. One of Mr. Noblet's current interests is incremental sampling methodolgy, a potentially much more powerful soil sampling methodology than traditional discrete soil sampling.

Todd Bernhardt, Principal

Practice Areas: Human Health Risk Assessment, Site Investigation and Characterization, Exposure Assessment, Toxicology, Risk Management, and Risk Communication

Mr. Bernhardt has more than 16 years of experience in environmental consulting, with emphasis on human health risk assessment, site investigation and characterization, vapor intrusion modeling, and toxics regulations compliance. He has managed or performed multi-pathway risk assessments for numerous properties under both federal and state regulatory programs, including power plant sites,  utility service stations, former manufactured gas plants, and naval installations, and has served as the primary client and agency point of contact for all risk-related issues for these properties. In addition, he has completed several consumer product risk assessments for Proposition 65 (California's Safe Drinking Water and Toxic Enforcement Act) compliance, and he has provided technical support for tesimony in toxics-related litigation.

Craig Pelletier, P.G., Principal

Practice Areas: Brownfields Redevelopment, Site Investigation and Remediation

Over the past 20 years, Mr. Pelletier has designed and executed hundreds of subsurface investigations, coordinated several emergency response jobs, and worked on fast-track brownfield redevelopment projects with challenging environmental problems. He assists clients with the development and implementation of numerous remediation programs involving soil excavation, soil vapor extraction, dual-phase extraction, air sparging, bioremediation, phytoremediation, chemical injections, and groundwater pump and treatment. With a focus on practical solutions, Mr. Pelletier works closely with developers, engineers, toxicologists, and regulatory agencies to lead his clients to favorable results.