Layering Institutional Controls Region 9 Example. Alana Lee EPA Region 9

Transcription

1 Layering Institutional Controls Region 9 Example Alana Lee EPA Region 9 March 18, 2014

2 ICs EPA Guidance Institutional Controls: A Guide to Planning, Implementing, Maintaining, and Enforcing Institutional Controls at Contaminated Sites (PIME IC Guidance, EPA 2012) OSWER VI Guidance - Section 8.6 (OSWER Final Guidance for Assessing and Mitigating the Vapor Intrusion Pathway from Subsurface Sources to Indoor Air Guidance External Review Draft ( EPA 2013) ICs: non-engineered instruments - administrative or legal controls, to help minimize potential exposure and protect integrity of response action Examples: land or use restrictions at site by conveying notice to stakeholders regarding subsurface contamination or possible need to refrain from certain actions to minimize/prevent potential exposure May use to secure access to property or require responsible party to conduct response activities (installation or monitoring and maintenance of VI mitigation systems)

3 R9 Site Example: MEW and NAS Moffett Field Location

4 EPA Proposed Plan (2009): Common Elements Monitoring & ICs Monitoring to ensure remedy is effective and protective of human health Each Alternative consisted of an appropriate engineering control and Institutional Control. Institutional Controls what are they? - non-engineered legal and administrative tools to help minimize the potential for exposure to contamination and to ensure the protectiveness of an engineered remedy. 4 Examples: Health and safety ordinances, zoning restrictions, building or excavation permits, and land use covenants.

5 VI Remedial Action Objective (from 2010 Record of Decision Amendment) To ensure that building occupants (e.g., workers and residents) are protected from Site contamination by preventing subsurface Site contaminants from migrating into indoor air or accumulating in enclosed building spaces exceed indoor air cleanup levels for long-term exposure. VI Remedy = Engineering Controls and Institutional Controls Existing Residential and Non-Residential Buildings Future (New Construction) Buildings/Properties 5

6 Vapor Intrusion Remedy Building Scenario Selected Vapor Intrusion Remedy Existing Buildings (Non-Residential and Residential) Tier 1 and Tier 2 Buildings Building with indoor air concentrations greater indoor air cleanup levels and outdoor background levels Tier 3A and 3B Buildings 3A -indoor air concentrations less than indoor air cleanup levels and greater that outdoor background levels; 3B - indoor air concentrations at or within outdoor background levels Tier 4 Building - There is no potential for VI into the building exceeding indoor air cleanup levels) Future Buildings (Non-Residential and Residential) Active Sub-slab/Sub-membrane Ventilation, Monitoring, and ICs*. ICs consist of: permitting and building requirements to install appropriate engineering controls in future construction; recorded agreements for non-residential buildings in MEW area to ensure installation and operation of engineering controls; require information be provided to future owners; require information of building changes be provided to EPA and Implementing Parties; and tracking service to provide information to EPA and Implementing Parties of occupancy and building changes, No Engineering Control. Monitoring and ICs. ICs consist of: permitting and building requirements to install appropriate engineering controls in future construction. No vapor intrusion remedy required for building or future building on property Tier A - Future new building where lines of evidence indicate there is the potential for vapor intrusion into the building above EPA s indoor air cleanup level. Tier B - Future new building where lines of evidence indicate there is no potential for vapor intrusion into the building above EPA s indoor air cleanup level. Passive Sub-Slab Ventilation with Vapor Barrier (Ability to Convert to Active), Monitoring, and ICs**. ICs consist of permitting and building requirements to install appropriate engineering controls. Recorded agreements remain in place for non-residential buildings. Perform indoor air sampling after building is constructed to confirm that there is not potential vapor intrusion risk and indoor air cleanup levels are met. If confirmed, then re-categorize as Tier 4, no further action is required. Notes: * Alternatively, Active Indoor Air Ventilation System, Monitoring, and ICs (including conduit sealing) may be selected as the vapor intrusion remedy for Tier 1 and 2 existing non-residential buildings if the property/building owner agrees to use, operate and monitor the indoor air ventilation system (e.g., HVAC) in a manner consistent with the operations, maintenance, and monitoring plan developed for that building, in a signed recorded agreement. ** Alternatively, Active Sub-slab/Sub-membrane Ventilation, Monitoring, and ICs (including conduit sealing) may be selected as the vapor intrusion remedy for Tier A future buildings. 6

7 Purpose of Institutional Controls Ensure engineering controls used to prevent indoor air contaminant levels from reaching EPA s indoor air cleanup level are implemented, operated, and monitored as required by the remedy Access to install and operate stand-alone building remedy, as necessary Ensure appropriate remedy installed in new development Inform building owners, managers, and occupants of remedy and its requirements Inform responsible parties and EPA when building ownership, new construction or building configuration 7 changes 7

8 Types of ICs Used Vapor Intrusion Remedy Types of ICs Used Governmental Controls formalized planning and permitting requirements (require appropriate VI control system in new construction buildings, require design/construction plans obtain EPA approval) Proprietary Controls requires recording of agreements between Implementing Parties and property owners at any property where engineered VI control in place. Enforceable and binding on successors. Must include notice to future building/property owners of the VI remedy requirements, access for sampling, OM&M, notice to EPA and Implementing Parties when changes to building/property ownership that could impact VI remedy For future construction layered with governmental controls (City s permitting and planning process and procedures)

9 Residential and Commercial MEW VI Study Area Residential and Commercial Usage

10 A City s Review is Complex for VI Issues - Example Varied Stakeholders Owner Contractor Tenant Developer Local Government Review Allowed Activity or Use Community Development Discretionary Planning Ministerial Permits Zoning Public Works Streets/Utilities Maintenance City Manager Redevelopment Business License Environmental Information Source to other departments Fire Occupancy Inspections Emergency Response

11 Informational Devices Vapor Intrusion remedy requires additional measures: - Creation of mapping database (GIS) to keep interested parties informed on properties within VI Study Area - Use of informational service to provide information to EPA and Implementing Parties regarding activities in the VI Study Area that could impact the remedy, including changes to property ownership or occupancy and permitting applications for new construction regarding remedy and information exchange

12 Activity Alerts VI Study Area MEW Site with Study Area

13 Recent Property Sales in MEW VI Study Area Recent Property Sales in MEW Study Area

14 California Environmental Quality Act (CEQA) Notice Zoning Change CEQA Notice

15 Building Permit Activity in MEW VI Study Area Building Permit Activity in Study Area

16 Excavation Activity in MEW VI Study Area Excavation Activity in Plume (zoom with image overlay)