Carousel Tract Environmental Remediation Project Update by Expert Panel to Regional Board July 11, 2013

Overview 1.Expert Panel Members 2.Scope of Work and Deliverables 3.Current Phase: Review of the Site-Specific Cleanup Goal Report (SSCG), including property-specific evaluations that involve a Human Health Screening Risk Evaluation (HHSRE) – Review criteria/principles – Analysis/concerns that arise when applying review criteria – Unknowns 4.Next Steps

Expert Panel Chair: J.R. DeShazo, PhD Professor of Public Policy, UCLA Economist with specialist in environmental policy and planning Member: Arturo Keller, PhD Professor of Biochemistry, UC Santa Barbara Expert on fate and transport of pollutants, treatment of contaminated water and soil, and remedial technologies Member: Gary Krieger, MD, MPH, DABT, DTM&H Lead author of guidance on health impact assessment for USA, also expert on risk assessment and medical toxicology

Scope of Work Overview Expert Panel charged with providing technical assistance to the Regional Board to support their decision making. This involves reviewing site information and making recommendations that the Regional Board will consider in evaluating Shell Oil’s proposed site-specific cleanup goals and the upcoming Remedial Action Plan. Expert Panel Members are third party, independent evaluators of appropriate scientific, technical and policy protocols.

Deliverables 1)Review of Human Health Screening Risk Evaluations (HHSRE) and Site-Specific Cleanup Goal Report (SSGC) – Interim Report to Regional Board by end of July, )Review of Remedial Action Plan – Report that provides recommendations to Regional Board

Review Criteria for the HHSRE and SSCG 1.Transparency – logic and underlying assumptions should be clearly presented. 2.Consistency – methodological approaches should utilize appropriate guidance and procedures and disparities minimized/explained. 3.Objectivity – there should be relevant and reasonable complete databases. 4.Sensitivity – should explain how risk-based decisions are dependent on variability and uncertainty.

Background The SSCG utilizes over 550 Reports that contain property- specific investigations and include a Human Health Screening Risk Evaluation (HHSRE). The HHSREs (various dates 2009/2010/2011) provide an initial evaluation, residential property by property, of potential risks. Concern: Not clear whether 1) the HHSREs are now considered to constituent the “full” human health risk assessment or 2) whether a human health risk assessment is scheduled for release in the future. Concerns with either scenario.

Analysis: Overview 1. An impressive amount of data has been presented by knowledgeable and sophistical practitioners. 2. Critical stakeholders should be able to more clearly follow a transparent, consistent and objective analysis that includes sensitivity analysis of key assumptions and technical decisions.

Analysis: Approach 1.Was the data collected analyzed in the most appropriate and rigorous way? 2.Was the risk potential of chemicals of concerns appropriately calculated? 3.Were all appropriate chemical of concerns included in the SSCG? 4.What are the critical unknowns or uncertainties?

Selected Examples 1.Lack of consistency between selecting potential chemicals of concern (COCs) between the SSCG and HHSRE. Calculated media-specific SSCG would mathematically change (become more stringent) if the COC process used in the HHSRE was utilized. Different methodologies should be highlighted and impacts of this decision characterized (sensitivity). 2.Questions over consistency and objectivity used for risk screening levels. 3.Concerns about methodology questioned when some analyses (e.g. to determine whether there is a sub-slab vapor to indoor air VOC transfer) aggregates across properties and mixes time periods.

Examples of Unknowns 1.Extent of the groundwater plumes (different plumes for different COCs) are not explicitly determined in information provided. 2.Sources and risk of chlorinated VOCs (lack of maps hinders this analysis).

Approach to Rule “Maximum Social Benefits” clean up Subject to what is “economically and technically feasible” 1.In which land uses would these properties yield the maximal social benefits? 2.How much has the long-run private and social value of these properties been impacted? 3.What other private and social value losses (e.g., transient interim-use value losses) might have been incurred?

Next Steps By end of July: Expert Panel will provide Regional Board with interim report on their review of SSCG report. Will review Remediation Action Plan. Make final recommendations based on consistency with scientific, technical and legal protocols, including State Water Board Resolution