Cleanup Criteria Rules 2017 Proposed Rules for the Volatilization to the Indoor Air Pathway (VIAP) Matthew Williams, Vapor Intrusion Specialist Remediation and Redevelopment Division 1
A new Paradigm! www.flickr.com *MPCA, 2016 2
2017 Public Information Meetings “Comprehensive Package” DATE TIME LOCATION Holiday Inn Ann Arbor October 11, 2017 6:00 pm - 8:00 pm 3600 Plymouth Road Ann Arbor, MI 48105 Grand Traverse Resort October 18, 2017 10:00 am - 12:00 pm 100 Grand Traverse Village BLVD Acme, MI 49610 L.V. Eberhard Center Grand Valley State University October 26, 2017 10:00 am - 12:00 pm 301 West Fulton Street Grand Rapids, MI 49504-6495 • 2017 PUBLIC COMMENT PERIOD To be announced • 2017 PUBLIC HEARING To be announced 3
Proposed Rule 27 • Volatilization to the indoor air pathway (VIAP) – Shallow groundwater • Situations where groundwater may be close or in contact with a building • Direct volatilization to the indoor air is likely to occur – Groundwater • Situations where groundwater is deeper than a typically constructed building • Vapor Intrusion (VI) is likely to occur – Vapor – Soil 4
Tiered Approach For the VIAP Conceptual Site Model (CSM) • Common in modern risk-based guidance VI Tier 1 Generic Screening Levels • Intended to promote: – Efficiency VI Tier 2 – Better Unrestricted Residential Criteria Available Data characterization • Other key features: VI Tier 3A Generic Criteria – Self implemented • Through VI Tier 3A VI Tier 3B – Flexible Site-Specific 5
VI Tiered Process VI Tier 1 VI Tier 2 VI Tier 3A *images from vastree.com *University of Wisconsin Facility-specific inputs Facility-specific inputs to to establish Screening Value establish Restricted Generic Unrestricted Generic Criteria Residential Criteria 6
Facility-specific vs Site-specific Facility-specific Site-specific VI Tier 2 and 3A VI Tier 3B Department pre-approved Approach that better values reflect site conditions Proposed values to the Align to site conditions Department Department Approval Implement Implement 7
Tiered Approach For the VIAP • VI Tier 2 establishes a facility • RBCA Tier 1 is NOT the same as VI Tier 1 – RBCA Tier 1 is the VI Tier 2 • VI Tier 3A aids in identifying land/use restrictions 8
Remediation and Redevelopment Division www.michigan.gov/deqrrd • Leaders in environmental stewardship • Partners in economic development • Providers of excellent customer service
Tier 1 Screening Levels 10
Depth to Groundwater Single Parameter Sensitivity Analysis Hazardous Substance Benzene Tetrachloroethylene Trichloroethylene CAS # 71432 127184 79016 Depth to GW µg/L µg/L µg/L <3m 1 1.5 0.073 Just >3.0m 14 96 6.1 5m 18 130 7.8 10m 27 200 12 Deeper the groundwater is, the more a hazardous substance is likely to diffuse before a structure 11
Soil Type Single Parameter Sensitivity Analysis Hazardous Substance Benzene Tetrachloroethylene Trichloroethylene CAS # 71432 127184 79016 UNITS µg/kg µg/kg µg/kg Sand 1.7 6.2 0.33 Loamy Sand 11 41 2.3 Sandy Loam 33 120 7.0 Loam 120 450 27 Larger particles (e.g., sand) means more pore space and easier migration of soil vapors 12
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