Roux Blog

New Tool Validated for Vapor Intrusion Litigation:
Stable Isotope Fingerprinting

The increased regulatory focus on vapor intrusion has led to the development of better tools for determining the source(s) of VOCs in indoor air. One such tool is compound specific isotope analysis (CSIA). CSIA is a well-established method for fingerprinting of pure chemicals and groundwater contamination. CSIA compares molecular structures between two samples of the same material in order to determine the likelihood that they originated from the same source. While this approach has been applied to VOCs in indoor air, there has been some hesitation to use it in a litigation context given the lack of an established methodology. However, in the last month or so, two major developments have occurred that pave the way for utilizing this methodology for litigation related to vapor intrusion source attribution.

This presentation will provide an overview of typically vapor intrusion source attribution issues, then review and discuss the lessons learned and implication from:

• The 9th Circuit court, in City of Pomona v. SQM North America Corporation, issued 5/2/14, which held that stable isotope analysis (for perchlorate in this case) meets the Daubert standard for admissibility.
  
  

• The US Department of Defense’s environmental technology demonstration and validation program, ESTCP, issued a report titled “Use of Compound-Specific Stable Isotope Analysis to Distinguish between Vapor Intrusion and Indoor Sources of VOCs”.

These developments facilitate the use of isotope analysis techniques that can be effectively and efficiently employed to reduce uncertainty and answer questions that otherwise would be extremely difficult and costly to address.

If you are interested in learning more about the above topic, contact Roux via the button below to request or schedule a technical brown bag tailored to your needs.

Technique for Identifying Source(s) of Indoor VOCs Now Positioned to Survive Daubert Challenge

Until recently, vapor intrusion was not a major concern at contaminated sites. Now there is a realization that indoor air impacts can be the most direct exposure to people from subsurface contamination. In addition, the new ASTM Phase I standard creates much greater visibility for the potential for vapor intrusion. While measuring concentrations of VOCs in indoor air is a well-established practice, determining the source of the VOCs has often been problematic:

• Is subsurface contamination actually contributing to indoor air VOCs?

• Are outdoor air concentrations of VOCs a major contributor to indoor levels?

• Are potential indoors sources of VOCs, such as dry cleaning, aerosols, paint, solvents, etc., distinguishable from vapor intrusion?

• Do VOC concentrations continue to show up inconsistently, even after remediation, but you cannot exclude the possibility of residual soil vapor as a source?

The increased focus on vapor intrusion has led to the development of better tools for determining the source(s) of VOCs in indoor air. One such tool is compound specific isotope analysis (CSIA). This is a well-established method for fingerprinting of pure chemicals and groundwater contamination. CSIA compares molecular structures between two samples of the same material in order to determine the likelihood that they originated from the same source. While this approach has been applied to VOCs in indoor air, there has been some hesitation to use it in a litigation context given the lack of an established methodology. However, in the last month or so, two major developments have occurred that pave the way for utilizing this methodology for litigation related to vapor intrusion source attribution.

1. The 9th Circuit, in City of Pomona v. SQM North America Corporation, issued 5/2/14, held that stable isotope analysis (for perchlorate in this case) meets the Daubert standard for admissibility.

2. The US Department of Defense’s environmental technology demonstration and validation program, ESTCP, issued a report titled “Use of Compound-Specific Stable Isotope Analysis to Distinguish between Vapor Intrusion and Indoor Sources of VOCs”. This report provides the documentation needed for establishing a standard methodology and method validation to meet legal standards for admissibility and withstand Daubert challenges or state-specific expert witness thresholds (such as Sargon in CA).

These developments facilitate the use of isotope analysis techniques analysis that can be effectively and efficiently employed to reduce uncertainty and answer questions that otherwise would be extremely difficult and costly to address.  If you are interested in learning more about the above topic, contact Roux via the button below to request or schedule a technical brown bag tailored to your needs.

Mitigating Vapors & Minimizing Legal Liabilities from Vapor Intrusion

GRACast Webinar - Wed., June 11 - 12:00-1:30pm Pacific Daylight Time (GMT-07:00)

Vapor intrusion (VI) evaluation, mitigation, regulatory negotiations and legal perspectives are constantly evolving.  On Wednesday, June 11 (12:00-1:30pm PDT) Ms. Karen Nardi, Arnold and Porter, LLP and Dr. Angela Liang Cutting, PhD, PE, Roux Associates, Inc. will be presenting:

Mitigating Vapors & Minimizing Legal Liabilities from Vapor Intrusion

This GRACast will focus on the legal and engineering mitigation issues involved with VI from contaminated groundwater sites.  See below for some of the discussions included in the 90-minute webinar.

Legal:

Types of liabilities that are associated with vapor intrusion into indoor air in buildings, including obligation for groundwater cleanup, mitigation of indoor air conditions, and third party toxic tort type claims.

The differing interests of potentially responsible parties (PRPs), landlords, tenants, employers and building occupants.

A case study that focuses on recent developments in the Silicon Valley where EPA Region 9 has re-opened many of the federal Superfund sites and asked for a re-evaluation of vapor intrusion issues.

Some of the interesting policy and scientific questions involved in setting health-based standards for indoor air.

Kinds of advice lawyers can provide to clients in this rapidly evolving area of law, science and policy.

Engineering:

The approach relating to VI mitigation measures for a residential development in Silicon Valley. (The client acted upon legal advice to incorporate proactive VI mitigation measures at the proposed development when it was not mandated by the regulatory agency. The lead agency is Department of Toxic Substances Control.)

How to succeed in implementing cost-effective vapor mitigation by communicating effectively across multiple disciplines regarding the VI mitigation system design and incorporating the system into the Building Plan and Schedule.

The different components of the mitigation system, including the:
Vapor Barrier;
Passive Sub-Slab Depressurization System;
Active Sub-Slab Vapor Extraction System; and
Sub-Slab Vapor Monitoring System.

The legal/regulatory setting; operation, maintenance, and monitoring of the system.

To learn more or to register for this event, please click on the logo below: