Contaminated Sites Workshop – Science Advisory Board Projects

1. Contaminated Sites Workshop – Science Advisory Board Projects September 28, 2004

2. Agenda • Overview of the SAB • Risk Assessment in Contaminated Sites Management • High Risk Screening and Classification Process • Screening Risk Assessment • Level 1 – The SRA-1 Process • Level 2 – The SRA-2 Process • Other Standards and Guidance Initiatives

3. Overview of the SAB Paul West

4. Background • A unique model in British Columbia • Independent Board of Directors • Registered under the Societies Act • An agency at the University of Victoria • Funding from the Ministry of Water Land and Air Protection • A Recommendation of the Minister’s Panel on Contaminated Sites

5. First AGMOctober 14, 2004 Morris J. Wosk Centre for Dialogue 580 West Hastings Street Vancouver, BC 11:30 – 2:00pm Contact: Sara Alvarez in the SAB office sabcs@uvic.ca Additional information on Risk Guidance

6. Membership Criteria • Advanced degrees in pertinent science and engineering disciplines • Number of years experience • Professional credentials • Leadership in the discipline • Field or lab experience • Evidence of ability to produce peer reviewed or other professional literature

7. More Information The SAB’s website can be found at: www.sabcs.chem.uvic.ca • Terms of Reference • Constitution and Bylaws • Nomination Form • Contact Information • News and Recent Documents

8. Risk Assessment in Contaminated Sites Management Marc Cameron

9. Contaminated Sited and Risk Assessment • Site determined to be contaminted • Site with chemicals present at concentration greater than BC Numerical Standards or Criteria. • Section 16 of the Contaminated sites regulation states “The numerical standards, or the risk based standards prescribed in section 18 or 18.1, may be used in relation to the remediation of a contaminated site.”

10. Contaminated Sites Process

11. When is risk assessment is employed? • At some sites it is not possible or practical to remove substances due to technological, physical or financial constraints. • When a site owner selects the risk-based approach, it allows the risks associated with leaving substances in place to be estimated.

12. Risk Assessment Process

13. When is risk assessment is employed? • The mere presence of a substance or contaminant at a site does not necessarily constitute a risk. In order for a risk to exist, the following three basic conditions must be met: • substances must be present; • these substances must be able to cause toxic or other adverse biological effects — that is substances must be hazardous; and • pathways by which humans, animals or plants (receptors) may be exposed to substances must exist.

14. Risk Assessment • Risk assessment uses mathematical models to predict the dose (amount of chemical), which is the amount of a substance received by a receptor by any specific exposure pathway. • Provided that the safe dose is not exceeded, there is little risk that exposure to the substance will adversely affect the health of receptors.

15. Risk Assessment • Risk assessment is a tiered process with each tier generaly requiring the collection of additional and more detailed site specific information. • Tier 1 Screening Level • SRA1 • SRA2 • Tier 2 Baseline –deterministic • Tier 3 Detailed –focused on specific issues and often probabilistic

16. Risk Assessment in British Columbia • SAB to develop and oversee the development of Screening Level Risk Assessment Guidance and Detail Risk Assessment Guidance. • It is the intent of the SAB to have these guidance documents build on one another so as to reduce reduce, redundancy. • The screening level risk assessment looks at assessing pathways of exposure to receptors of interest.

17. Risk Assessment and Contaminated Sites

18. High Risk Screening and Classification Process Dennis Konasewich

19. Background – Panel report • Focus regulatory resources on high-risk sites • Establish stand-alone and independent system of licensed environmental professionals- allow them to oversee non-high risk sites • Establish SAB to develop screening level risk-assessment methodology

20. Ministry’s proposed process • Investigation and remediation of all but high risk contaminated sites under licensed professionals. • Ministry will guide and direct remediation process on high risk contaminated sites and sites undergoing risk-based remediation • Ministry will also review and develop new standards and protocols.

21. Compliance acceptance • Retain existing approach of using numeric standards to classify a site • Added two protocols: high risk identification, and pathway/receptor screening assessment

22. Ministry requirements for identification of high risk contaminated sites • Level 1: Initial high risk procedure largely consisting of prohibiting conditions • Level 2: Development of high spot numbers representing concentrations capable of causing significant harm and in combination with other prescribed conditions • Level 3: Consideration of a scoring system for classification

24. Definition of a “high risk” contaminated site-WLAP references • WMA 27.1(8) reference to “imminent and significant threat or risk to human health, given current and anticipated human exposure, or the environment“ • Sites that require immediate regulatory attention

25. High risk identification process must: • Be representative of good science • Be pragmatic • Enable a reasonable selection process • Assure high risk sites are appropriately identified • Assure that the number of “non-high” risk sites selected as “high risk” is minimal.

26. Time-frame for SAB • Report status to the Ministry September 30 • Undertake additional work and complete draft procedure by November 15 • Present SAB reviewed draft to the Ministry on November 30

27. Approach • Discussion with Ministry • Discussions with consulting community • Discussions with federal agencies • Literature Review • Consideration of approaches already developed • Workshop • Board discussions

28. Screening Risk AssessmentSRA-1 Status Report Will Gaherty

29. Context of SRA-1 • SRA-1 - simple rules - all LEPs • SRA-2 - simple models - some LEPs • DRA-1 - simplified risk assessment - MWLAP • DRA-2 - unconstrained risk assessment - MWLAP

30. What is SRA-1? • Avoid “full blown” risk assessment at lowest risk sites that exceed numerical standards • Few if any similar approaches elsewhere, so built from scratch

31. What is SRA-1? • 12-17 “yes/no” questions total, in three modules • Human and ecological risk • Minimal professional judgement (audit/liability)

32. How it works? • Barriers • Distance to receptors

33. Comments on Draft • Comments from roughly 8 sources • General feeling that SRA1 highly restrictive • Comments helpful, but SRA2 had more impact

34. Revisions • Framework basically unchanged from original draft • Clarification of a number of issues • Questions quite different

35. Where Next? • Limited circulation now • Submit to MWLAP in next week or so • Field trials will tell a lot • Science moving fast in some areas • Experience with SRA2 will help, too

36. Screening Risk AssessmentSRA-2 Status Report Jean Cho

37. Outline • Pathways Evaluated in SRA-2 • Vapour Intrusion into Occupied Buildings • Leaching of Soil Contaminants to Groundwater • Transport in Groundwater to Water Supply Well • Transport in Groundwater to Aquatic Receptor • Habitat Viability Issues Also Addressed

38. Schematic of Pathways

39. Pathway 1 – Soil Vapour Intrusion • Input from 14 Scientists and Engineers • 7 SAB Members • USEPA, Health Canada, MWLAP, U of A, U of T • 6 Consultants • 3 Reviewers

40. Pathway 1 – Soil Vapour Intrusion • Partitioning • Vapour Attenuation • Indoor Air Concentration • HQ (hazard quotient) orILCR (incremental lifetime cancer risk)

41. Pathways 2 to 4 – Soil / GW • Presented in a Single Document • Input from 20 Scientists and Engineers • 12 SAB Members • GSC, UBC, MWLAP, WA state, CPPI • 8 Consultants • 4 Reviewers • Pathway 2 Based on US EPA Soil Screening Guidance

42. Pathway 3 – Groundwater to Well • Aquifer Classification • Suitability as resource • Potential for future use • Vulnerability

43. Pathways 3 & 4 – Groundwater Transport • Quantify risk using cross-plots • Sensitivity Analysis • Cleanup Standard

44. SRA-2 Habitat Assessment • Input from 13 Scientists and Engineers • 7 SAB Members • USEPA, MWLAP, Western Washington U. • 6 Consultants • 3 Reviewers

45. SSS Model Review • Part of Protocol 2 • Two external reviews • Chris Neville of Papodapulos & Associates • Jean Cho • Opinion letter from John Cherry

46. Other Standards and Guidance Initiatives Jim Malick

47. Completed Projects (Posted) • Initial Review of CCME Canada Wide Standards for Petroleum Hydrocarbons • SRA1 – Initial Draft: Screening Risk Assessment Level 1 Guidance (May 2004) • Report of the EPH/LEPH/HEPH Task Force

48. Other Projects in Progress • Detailed Risk Assessment 1 (DRA-1) – Standard, deterministic • Detailed Risk Assessment 2 (DRA-2) – Extended, including stochastic methods • Review of Contaminated Soil Standards Task Group (CSST) Standards Derivation Protocol

49. Other Projects in Progress Cont. • Recommendations for revision of Soil Groundwater Model (Based on Completed Review) • Further recommendations on NSTS (Non-Scheduled Toxic Substances)