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Vapor Intrusion

  • Land Recycling Program TGM Section IV: Vapor Intrusion (PDF) – The revised VI Guidance has been included as section IV of the revised TGM which was published and effective on January 19, 2019 (261-0300-101, eLibrary). Note: As of October 13, 2022, there have been screening values added for mercury for indoor air, sub-slab, and near-source sampling data as well as the ability to use the J&E model for soil vapor (near-source sampling) data. The TGM will be updated to reflect this in the next revision.

  • Vapor Intrusion Screening Value Tables (Excel) – These screening tables are updated when the numeric values used to calculate the Act 2 medium-specific concentrations (MSCs) are revised via Chapter 250 rulemaking.

  • Table IV-A-1: Volatile Substances Without Inhalation Toxicity Data (PDF) – This table provides a list of volatile substances that do not have inhalation toxicity data. See TGM Appendix IV-A for additional information.

  • Table IV-A-5: Vapor Intrusion Screening Value Calculation Parameters (PDF) – This table provides the parameters used for VI screening value calculations. The toxicity parameters used are from Chapter 250, Appendix A, Table 5A.

  • A Note on Practical Quantitation Limits (PQLs): Laboratory detection limits are sometimes higher than the associated screening values. Act 2 specifies that in demonstrating attainment of any standard, the concentration of a regulated substance shall not be required to be less than the PQL set by EPA. Vapor intrusion is a pathway and not a media for which attainment can be demonstrated but evaluation of the VI pathway is necessary to attain the Statewide health and the site-specific standards for soil and groundwater. EPA does not currently publish PQLs for the Toxic Organics (TO) series methods. PQLs are laboratory-specific and instrument-specific so PQL values will vary from one laboratory to another. Because of this, it was determined that the VI Relative List of PQLs previously provided on this website was no longer useful and has been removed. Laboratories should be consulted prior to sampling to obtain PQL values if possible or the procedure in § 250.4(b) can be used in developing PQLs for the TO-series analytical methods. Laboratories should also be consulted prior to sampling to obtain method detection limits (MDLs) and reporting limits (RLs) for the compounds of interest. The calibration data associated with individual data sets should be included when providing analytical laboratory results to the Department.

  • Vapor Intrusion Guidance Frequently Asked Questions (FAQ's) - April 2023 (PDF): Questions about the VI guidance that have been frequently asked or that the Department anticipates will be frequently asked are addressed in this list of FAQ's. This document will be periodically updated as new questions are received. The date at the top of the document indicates when the document was last updated

  • PA DEP Johnson & Ettinger (J&E) Models – DEP has developed PA-specific J&E model spreadsheets (below) to be used to calculate indoor air concentrations or to calculate risks associated with the indoor air pathway. Remediators should use DEP's version of the models which are based on EPA's advanced model version 3.1 spreadsheets with PA-specific model inputs. Additional information on the development and application of the models can be found in Appendix B of Section IV of the Technical Guidance Manual. These models will be periodically updated to add the most up to date toxicity information. The date listed on each spreadsheet link below corresponds to the date the spreadsheet was last updated.

The Land Recycling Program (LRP) partnered with the Pennsylvania Council of Professional Geologists to conduct training on the new vapor intrusion guidance that became effective January 18, 2017. The training sessions were one-day courses that presented an explanation of the vapor intrusion guidance along with four exercises based on a case study. The slides and exercise materials from the final session in Malvern on January 10, 2017 are provided below.