Update

Vapor Intrusion

A proposed new ASTM International standard will link easy to use, cost-effective and nonintrusive passive sampling with concentration data to measure vapor intrusion. WK40037, Guide for Determining Concentration Values from Groundwater, Air and Soil Gas Using Adsorbent-Based, Passive Samplers, is being developed by Subcommittee D18.21 on Groundwater and Vadose Zone Investigations, part of ASTM International Committee D18 on Soil and Rock.

Vapor intrusion, the migration of gas-phase compounds from underlying soil into confined structures, is a potential health risk that has received increased attention from regulators. Use of WK40037 will increase the possibility that health problems associated with vapor intrusion will be avoided.

“The materials or products covered by WK40037 are passive, adsorbent-based samplers,” says Lorne Everett, chief scientist, L. Everett and Associates LLC, and chair of the D18.21.02 task group. “The samplers are commonly used by environmental consultants and regulators, deployed and retrieved by the user, then shipped to an off-site laboratory for analysis and data reporting.”

Measurement of the sampling rate in air to determine gas-phase compound concentrations is well-documented in industrial hygiene literature. However, measuring such concentrations in soil gas and aqueous environments using a passive sampler is less well-documented.

WK40037 will demonstrate that a compound concentration in air, soil gas or water can be measured accurately, in a cost-effective manner, providing defensible quantitative data that will be accepted by regulatory agencies.

“WK40037 will summarize the technical approach in a manner that a user with some scientific background can understand,” says Everett. Use of WK40037 will increase the confidence that concentrations reported with a passive sample are accurate and will thus broaden the acceptance of passive samplers.

The dynamic behavior of soil gases is an emerging issue for vapor intrusion risk calculations. Continuous soil gas analysis, active soil gas sampling, barometric pressure influences and soil moisture variability are being addressed by D18.21.02.

CONTACT Technical Information: Lorne G. Everett, Ph.D., L. Everett and Associates LLC • Santa Barbara, Calif. • Phone: 805-880-9301 | ASTM Staff: Robert Morgan • Phone: 610-832-9732 | Upcoming Meeting: June 9-12 • June Committee Week • Indianapolis, Ind.

This article appears in the issue of Standardization News.