Presentation for City of Brisbane Final Peer Review

Presentation for City of Brisbane Final Peer Review Findings November 7, 2005 (Revised May 10, 2006)

Presentation Outline u Purpose u Project Overview u Summary of Findings u Background and Regulatory Framework u Objectives and Evaluation Criteria u Findings u Recommendations u Discussion

Purpose u Update April 2005 workshop u Supplemental data u Refine findings u Information to date u Update recommendations

Project Overview u Baylands project area u u Former Brisbane landfill Southern Pacific Railroad facility u Phase 1 development u Former Brisbane landfill u Future development phases u Southern Pacific Railroad facility

Site Map Modified from Workshop Presentation to the City of Brisbane, Brisbane Baylands, Subsurface Environmental Conditions by Universal Paragon Corporation and Burns & Mc. Donnell Engineering Company, Inc. , November 18, 2003.

Summary of Findings – Landfill Evaluation category Risk assessment • Human health • Ecological Assessment • Evaluations incomplete • Final assessments pending Limits of waste • Adequately defined, except for southern boundary • Agree with plan to extend landfill cap to edge of Guadalupe Channel Landfill Settlement • Evaluation incomplete • Future studies needed Landfill gas • Concur majority of organic waste is decomposed • Recommend re-initiation of monitoring activities Groundwater Quality • Adequately characterized. Leachate • Seeps into surface and groundwater adequately characterized Remedial approach • Evaluation incomplete – dependent on approved development plan • Final closure plan not prepared but will address: • Gas control system • Final cover and surface water control • Settlement • Human Health and Ecological assessments

Summary of Findings – OU-1 Evaluation category Risk assessment • Human health • Ecological Assessment • Evaluations incomplete • Final assessments pending Groundwater • Generally adequately characterized • Treatment system mitigates infiltration into Sunnydale Sewer • Additional information is needed for • DNAPL source (residual or upgradient) • A-aquitard discontinuity/B-Aquifer contaminant mechanism • RAP in DTSC review Soil • Evaluation incomplete • DTSC request additional work – • Site characterization • Remedial action workplan Surface water • Adequately characterized • Groundwater treatment system mitigates infiltration into Sunnydale Sewer Soil vapor • Future studies likely needed based on final development plan Remedial approach • • Evaluation incomplete Remedial action plans in review/preparation Overall proposed approach consistent with industry practice Final RAP dependent on approved development plan

Summary Findings – OU-2 Evaluation category Risk assessment • Human health • Ecological Soil & groundwater Soil vapor Surface water Remedial approach Assessment • Evaluations incomplete • Final assessments pending • Adequately characterized • Depending on final approved development plan, future studies may be required • Adequately characterized • Interim approach consistent with industry practice • Soil vapor study may be required for potential vapor migration • Final RAP dependent on approved development plan • Adoption of future RWQCB Site Cleanup Order

Background and Regulatory Framework u Brisbane Landfill u u Former municipal landfill (1933 -1967) RWQCB and County of San Mateo Environmental Health Division (County) u Groundwater Operable Unit 1 (OU-1) u u Former Southern Pacific Railroad Facility (19141960) and Schlage Lock Facility (1926 -1999) California Department of Toxic Substances Control (DTSC) u Groundwater Operable Unit 2 (OU-2) u u Former Southern Pacific Railroad Facility (19141960) RWQCB

Objectives and Evaluation Criteria u Objectives u u u Provide independent technical review Serve as community advocate Support the dissemination of project information u Evaluation Criteria u u u Adequacy of environmental characterization Appropriateness of remedial action Protective of public health and environment

Peer Review Role In Baylands Planning Process

Findings – Brisbane Landfill Adequacy of Environmental Characterization u Evaluation adequate – – u Limits of waste, except for southern boundary Landfill gas Groundwater quality Leachate Evaluation incomplete – Landfill settlement

Findings – Brisbane Landfill Cont. u Appropriateness of Remedial Action u u Final remedial action plan not developed Primary issues associated with landfill closure – – – u Landfill gas generation and migration Leachate generation and transport into groundwater and surface water Settlement of the landfill surface Proposed concept is appropriate – Lacks sufficient detail

Remedial Approach – Brisbane Landfill

Findings – Brisbane Landfill Cont. Protective of Public Health and Environment u Overall concept appropriate – final evaluations not complete u u Final closure plan - not prepared Final risk assessments - not prepared u Human health u Primary concern – Landfill gas u Ecological u Primary concern – Leachate seeps

Findings – Operable Unit 1 Adequacy of Environmental Characterization u Primary site contaminants u VOC’s, TPH as Bunker C, metals u Soil – Evaluation incomplete u Additional investigation requested by DTSC u Revised RAP in progress u Groundwater – Generally characterized u Clarification needed for: – – A-zone aquitard continuity (‘windows’) B-zone contamination source u Soil Vapor – Evaluation incomplete u Risk Assessments – Evaluation incomplete u Pending final development plan

Site Map – Operable Unit 1

Stratigraphic Terminology Possible Gap

Simplified Conceptual Aquifer Development West East

Findings – Operable Unit 1 Cont. Appropriateness of Remedial Action u Remedial approach u u Limited soil excavation at two locations (VOCs) Continued operation of groundwater treatment system – – u u u Add three extraction wells Add two monitoring wells Soil cap Vapor barriers, as needed Engineering and Institutional Controls – Reduce/eliminate human health exposure

Proposed Remedial Action – Operable Unit 1 (Profile)

Proposed Remedial Action – OU-1 Commercial Scenario Engineering Control – Restrict Groundwater Use Engineering Control – Outdoor Inhalation Engineering Control – Indoor Inhalation Legend Proposed Area of Soil Removal Proposed Additional GW Monitoring Well Proposed Additional GW Extraction Well Modified from Burns & Mc. Donnell, Revised Groundwater RAP, Operable Unit 1, January 27, 2005.

Findings – Operable Unit 1 Cont. Protective of Public Health and Environment u Evaluation incomplete u u u Site RAPs not complete Final development plan pending Proposed remedial concept – generally acceptable u Human health u Final risk assessment pending u Ecological u u Assessment not performed/identified Final risk assessment recommended

Findings – Operable Unit 2 Adequacy of Environmental Characterization u Primary site contaminants: u TPH as Bunker C, metals, VOCs u Soil and groundwater – adequately characterized u Surface Water - adequately characterized u Soil Vapor – evaluation incomplete u Risk Assessments – evaluation incomplete u Pending final development plan

Findings – Operable Unit 2 Cont. Appropriateness of Remedial Action u Remedial approach (interim) u Soil Cap - 7 to 10 feet clean soil – – u Abandon existing north-south drainage channel – u Leave in-place TPH and metals impacted soils Limited VOC soil removal (Spring 2006) Replace with interim drainage channel (Spring 2006) Engineering and Institutional Controls – – Reduce/eliminate human exposure Not defined/delineated

Site Contaminants – Operable Units 1 and 2

Proposed Remedial Action – Operable Unit 2

Findings – Operable Unit 2 Cont. Protective of Public Health and Environment u Evaluation Incomplete u Interim RAP approved by RWQCB u Final Site RAP pending u RWQCB Site Cleanup Order pending u Human health u Proposed remedial concept – generally acceptable – – – Final risk assessment pending Evaluate for applicability to current standards Soil vapor not evaluated u Ecological – acceptable u Proposed concept addresses ecological risk – – u Based on SFIA values Evaluate for applicability to current standards Overall interim concept appropriate – final evaluation not complete

Recommendations u General u Subarea specific u u u Brisbane landfill OU-1 OU-2 u Next steps u Note: not all steps required immediately

Recommendations – General u Financial assurance u Mechanism to manage long-term uncertainties associated with maintenance of streets, utilities, etc u Conceptual site model and remedial action plan u u u Integrated development-based Baylands plan Establish evaluation and remedial approach Develop early in project approval process u Continue evaluation of Baylands environmental documents and plans

Recommendations – Brisbane Landfill u Risk assessment u u Final human health assessment Ecological assessment u Landfill surface settlement evaluation u Settlement studies u Final cover design and construction u Landfill cover – – Single, integrated unit Prevent surface water infiltration and minimize leachate seeps

Recommendations – Brisbane Landfill Cont. u Landfill gas and monitoring u u Vapor barriers & methane monitoring Explosion proof construction – underground utilities u Groundwater monitoring u Post-closure monitoring program u Post-closure monitoring and maintenance plans

Recommendations – Operable Unit 1 u Provide additional information to address: u u Soil contamination – type and extent Groundwater – – – A-aquitard ‘windows’ DNAPL source B-Sand aquifer – VOC source u Consider benefits of in-situ treatment technologies u u Source reduction Augment proposed final remedial approach u Human health and ecological risk u Complete final assessments

Recommendations – Operable Unit 2 u Update soil remedial action plan u VOC soil vapor u Update soil management plan and residual risk management plan u Consider in-situ bioremediation treatment u u Source reduction Augment proposed final remedial approach u Human health and ecological risk u Complete final assessments

Recommendations – Operable Unit 2 Cont. u Prepare monitoring plan for post well abandonment and replacement plan u Assess the brick-lined arch sewer u Structural integrity for proposed tie-in u Evaluate long-term settlement u Final remedial approach consistent with future RWQCB site cleanup order

Recommendations - Next Steps u Develop integrated site conceptual model and development-based Remedial Action Plan u City meet with regulatory agencies to discuss path forward with respect to future requirements u Review revised specific plan and development concept u Evaluate future environmental documents as deemed necessary

Future Studies and Sequencing Future Studies & Program Sequence A OU-1 OU-2 B Prior to/concurrent with CEQA C Required by CEQA D Landfill Supplemental Data Review Development Plan E Post Development Plan

Discussion