Why should you consider helium as a leak tracer for Vapor Intrusion sampling?

When conducting vapor intrusion sampling, helium is an excellent choice as a leak tracer due to its precision and practicality. Helium is extremely effective in detecting minute leaks, allowing for accurate identification of potential intrusion points that might otherwise go unnoticed. This level of sensitivity makes it ideal for ensuring the reliability of sampling results.

One of helium’s key advantages is that it can be employed without the need for costly fixtures or specialized test chambers, making it a low-cost and accessible option for both small-scale and complex systems. Whether testing individual components or entire networks, helium can easily adapt to various testing environments, ensuring it is a practical solution for a wide range of applications.

Additionally, helium offers higher test sensitivity compared to other volatile alternatives. By increasing the concentration of the helium tracer gas, the precision of the testing process improves, enabling more accurate detection and measurement of potential leaks. This makes helium particularly valuable for situations where thoroughness and accuracy are critical.

Helium also possesses unique chemical properties that enhance its effectiveness as a tracer. As a large yet lightweight compound, it is easily retained during testing and less likely to escape prematurely. Its scarcity in the environment further minimizes the risk of background interference, ensuring that any detected helium during vapor intrusion testing originates solely from the testing process.

The rarity of helium in natural settings is another major benefit. While it is relatively rare, it remains stable and predictable in the environment, which reduces the risk of false positives. This reliability ensures that test results are accurate, allowing decision-makers to confidently assess vapor intrusion risks and implement necessary mitigation strategies.

By choosing helium as a leak tracer, professionals conducting vapor intrusion sampling can leverage a cost-effective, highly sensitive, and environmentally reliable tool that ensures precise, dependable results.

How does a helium shroud apparatus support soil gas sampling?

A helium shroud apparatus plays a critical role in supporting soil gas sampling by ensuring the integrity of the sampling process and delivering highly reliable data. Soil gas sampling is often performed to assess the presence of volatile contaminants that can migrate from subsurface sources into indoor air. The helium shroud enhances the accuracy of these efforts by providing a way to detect and prevent ambient air leaks that could otherwise compromise the validity of the collected samples.

The apparatus consists of several key components that work together to evaluate potential leakage. These components include helium detectors, soil vapor probes, real-time monitors, sampling pumps, vacuum chambers, and a portable gas chromatograph. Each element serves a vital purpose: the soil vapor probes collect the gas sample, while the pumps and vacuum chambers regulate airflow. Real-time monitors and helium detectors continuously track helium concentrations, and the gas chromatograph allows for on-site analysis, further expediting the identification of potential leaks.

During the testing process, the helium shroud is carefully positioned over the sampling area. Laboratory-grade helium is introduced into the shroud and maintained at a controlled level throughout the test. This ensures that if any leaks occur around the sample train or at the interface between the soil-gas tubing and the ground surface, they are immediately detected. The presence of helium at these points serves as a clear indicator of ambient air intrusion, helping technicians quickly identify and address any issues.

The use of helium as a tracer is particularly valuable because it offers real-time leak detection during fieldwork. This is essential for site clearance, especially for development projects, where public safety is paramount. Immediate detection allows for swift corrective action, reducing the likelihood of delays and ensuring that accurate data is collected for environmental assessment and remediation efforts.

However, one challenge associated with using helium is the global shortage, which can make it difficult to secure helium on short notice—especially when coordinating with restricted site access windows. Planning ahead becomes crucial for ensuring that helium supplies are available when needed, minimizing disruptions to the sampling process. Despite these challenges, the helium shroud apparatus remains a preferred tool for soil gas sampling due to its ability to detect leaks with precision, support real-time monitoring, and provide highly accurate data that supports environmental safety and compliance.

Why should you consider a helium shroud apparatus?

This technology is ideal for soil vapor sampling technicians, managers, and environmental consultants involved in modeling vapor intrusion and its movement through buildings as part of Environmental Impact Reports (EIRs).

In California, these considerations are especially significant due to several unique challenges:

• Homelessness Crisis: Housing Crisis: California is home to 15% of the nation’s population in families experiencing homelessness. The state’s housing shortage is worsening, and development efforts are increasingly hindered by overly conservative risk assessments.
• Regulatory Gaps: There is no standardized protocol from regulatory agencies to identify and remove outliers, complicating site assessments and long-term monitoring efforts.
• Public Health Standards: The Bay Area and San Francisco have stringent health requirements, with regulatory shifts continuing to push Environmental Screening Levels (ESLs) to stricter thresholds.
• Emerging Standards: States like Colorado, New Hampshire, Massachusetts, and Hawaii are rapidly developing their own guidelines, while the EPA is finalizing new federal vapor intrusion standards.
• Reevaluation of Guidelines: Vapor intrusion risks have been historically understudied, but current efforts are reexamining these risks, leading to evolving best practices.
• This evolving regulatory landscape underscores the importance of advanced sampling technologies, ensuring accurate assessments and supporting safe, efficient development.

Are there any drawbacks to using this method?

The main concern most often mentioned about helium shroud testing is regarding the use of laboratory grade vs “party grade” helium. Cost and availability concerns of laboratory-grade helium has led to some testing firms using commercially available tanks commonly used to fill balloons.

Compared to the quality control and consistency and purity of the helium in lab-grade tanks, party tanks can be filled from different sources and at different times, leading to sometimes significant variations in the quality of the helium.

One common compound often found in higher concentrations in party grade tanks is benzene – in such concentrations that would produce test results with significantly elevated levels.

Where is this technology going?

With the introduction of VaporDeck™, our newly patented and trademarked vapor intrusion testing apparatus, organizations can now achieve faster, more cost-effective, and compliant site development clearances. Without investing in this cutting-edge technology, developers may be forced into outdated approaches that carry heavy costs and risks:

• Extended Risk Assessments: Developers might spend unnecessary time and resources on lengthy risk assessments that could result in acquiring land that costs more to maintain than its return value.
• Costly Clean-Up Programs: Without VaporDeck™, organizations could find themselves locked into expensive, long-term remediation efforts that fail to fully clear sites for use.
• High-Maintenance Technologies: Developers may need to rely on alternative technologies that require extensive operational monitoring and maintenance—without a guaranteed timeline for completion or assurance of meeting increasingly stringent regulatory thresholds.

Next steps

Vapor intrusion is a very real concern and threat. Helium leak shrouds represent a distinct and viable testing option is accurate and can save valuable resources. To learn more about how we can assist you with your vapor intrusion detection and put our helium leak shrouds to work for you, please reach out.