Department of Health Seal

TGM for the Implementation of the Hawai'i State Contingency Plan
Section 7.0
SOIL VAPOR AND INDOOR AIR SAMPLING GUIDANCE

7.0 SOIL VAPOR AND INDOOR AIR SAMPLING GUIDANCE

This section of the Technical Guidance Manuall addresses the collection of subsurface soil vapor samples and indoor air samples. The guidance was developed following review of numerous guidance manuals, sampling protocols, technical reports and advisories published by the United States Environmental Protection Agency (USEPA) and other states, as well as other publications. A list of references consulted during development of this guidance is included at the end of the section.

The discussion of sample collection is preceded by an overview of the occurrence and nature of vapor plumes in the subsurface and the potential risks posed to outdoor air and overlying buildings. The development of HDOH soil, groundwater and soil gas (“vapors”) action levels for evaluation of vapor intrusion hazards is described in the document Evaluation of Environmental Hazards at Sites with Contaminated Soil and Groundwater (“EHE guidance;” HDOH 2016, see also HDOH, 2016b.). The discussion provided below and in Section 13 is intended to serve as a supplement to this guidance.