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

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Presentation on theme: "Presentation for City of Brisbane Final Peer Review Findings November 7, 2005 (Revised May 10, 2006)"— Presentation transcript:

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

2 Presentation Outline uPurpose uProject Overview uSummary of Findings uBackground and Regulatory Framework uObjectives and Evaluation Criteria uFindings uRecommendations uDiscussion

3 Purpose uUpdate April 2005 workshop u Supplemental data uRefine findings u Information to date uUpdate recommendations

4 Project Overview uBaylands project area u Former Brisbane landfill u Southern Pacific Railroad facility uPhase 1 development u Former Brisbane landfill uFuture development phases u Southern Pacific Railroad facility

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

6 Summary of Findings – Landfill Evaluation categoryAssessment Risk assessment Human health Ecological 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

7 Summary of Findings – OU-1 Evaluation categoryAssessment Risk assessment Human health Ecological 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

8 Summary Findings – OU-2 Evaluation categoryAssessment Risk assessment Human health Ecological Evaluations incomplete Final assessments pending Soil & groundwater Adequately characterized Soil vapor Depending on final approved development plan, future studies may be required Surface water Adequately characterized Remedial approach 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

9 Background and Regulatory Framework uBrisbane Landfill u Former municipal landfill (1933-1967) u RWQCB and County of San Mateo Environmental Health Division (County) uGroundwater Operable Unit 1 (OU-1) u Former Southern Pacific Railroad Facility (1914- 1960) and Schlage Lock Facility (1926-1999) u California Department of Toxic Substances Control (DTSC) uGroundwater Operable Unit 2 (OU-2) u Former Southern Pacific Railroad Facility (1914- 1960) u RWQCB

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

11 Peer Review Role In Baylands Planning Process

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

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

14 Remedial Approach – Brisbane Landfill

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

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

17 Site Map – Operable Unit 1

18 Stratigraphic Terminology Possible Gap

19 Simplified Conceptual Aquifer Development West East

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

21 Proposed Remedial Action – Operable Unit 1 (Profile)

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

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

24 Findings – Operable Unit 2 Adequacy of Environmental Characterization uPrimary site contaminants: u TPH as Bunker C, metals, VOCs uSoil and groundwater – adequately characterized uSurface Water - adequately characterized uSoil Vapor – evaluation incomplete uRisk Assessments – evaluation incomplete u Pending final development plan

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

26 Site Contaminants – Operable Units 1 and 2

27 Proposed Remedial Action – Operable Unit 2

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

29 Recommendations uGeneral uSubarea specific u Brisbane landfill u OU-1 u OU-2 uNext steps u Note: not all steps required immediately

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

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

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

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

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

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

36 Recommendations - Next Steps uDevelop integrated site conceptual model and development-based Remedial Action Plan uCity meet with regulatory agencies to discuss path forward with respect to future requirements uReview revised specific plan and development concept uEvaluate future environmental documents as deemed necessary

37 Future Studies and Sequencing Landfill OU-1 OU-2 Future Studies & Program Sequence ASupplemental Data Review BPrior to/concurrent with CEQA CRequired by CEQA DDevelopment Plan EPost Development Plan

38 Discussion


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