Holly LeClair, MS McDaniel Lambert, Inc.

1. Holly LeClair, MS • McDaniel Lambert, Inc.

2. The Case Unfolds . . . • Pipeline leaks in a sleepy beach town begins in the 1970s • Thriving tourist area impacted • 20,000 gallons of crude oil, diesel oil and gas • Contaminated soil and groundwater • Businesses and residences needed to be assessed to determine human and environmental risk

3. Bold Remediation Decision Phase one work on first area of site • Excavate • Cap and cover • Drill • Monitor Excavation begun 1998

4. The Excavating of Utopia, USA • Over 1/3 of tourism-economy, coastal town impacted • 25 building demolished • Utilities replaced • Several major streets reconstructed • Over 12,000 hauling truck trips • 200,000 gallons of diesel consumed by stationary and mobile equipment

5. Intense Scrutiny • The public outrage/media.

6. First Phase Completed • Air monitoring results from a 2000 study of samples taken while remediation activities were ongoing causes agency concern Air monitoring HHRA requested 2000 Excavation begun 1988 Excavation completed 2000

7. Ongoing Agency Concerns • “Are residents exposed to diesel exhaust during primary remediation, despite thresholds not being exceeded, at risk during future remediation?” Scrutiny, pressure and data from phase one affects proposed work on other site areas: Air monitoring HHRA requested 2000 Excavation begun 1988 Multi-agency team convened to weigh potential future issues 2003 Excavation completed 2000

8. Mclam Called In • In 2005 we were contracted for one site area to use data collected through 2004 to prepare a HHRA to evaluate the potential risks to current • nearby residents • recreators/tresspassers • future site users (no development plans)

9. Baseline HHRA Results • Our baseline HHRA concludes that risk at the tank farm exceed 1x10-6 Air monitoring HHRA requested 2000 Mclam prepares baseline HHRA 2005 Excavation begun 1988 Multi-agency team Convened to weight potential future issues 2003 Excavation completed 2000

10. Almost Finished . . . 04/08 1st draft submitted 08/08 2nd draft submitted 09/08 3rd draft submitted 04/10 4th draft submitted Air monitoring HHRA requested 2000 Mclam prepares baseline HHRA 2005 Excavation begun 1988 Multi-agency team Convened to weight potential future issues 2003 Mclam submits 1st draft of Supplemental HHRA 2008 Excavation completed 2000

11. Questions Emerged Wouldn’t a quantitative DQA ensure DQOs were satisfied? • Is there sufficient data to make health protective conclusions? • Weren’t the initial site sampling DQOs based only on visual inspection of site coverage and professional judgment?

12. A “Gut Check” Was Needed • All project members wanted assurance • We wanted confidence in our conclusions • Agencies were weighed by their responsibility to the community and wanted iron-clad analyses to base their decisions on • Responsible party could not fail after all the town had been through—company goodwill and future planning at the site were on the line

13. No Room For Error • Our HHRA to be used to make decisions about future use/development plans for the site. • How to move the process forward?

14. The Solution Found A powerful sleuth that can be called into action to check the validity of complex risk assessment projects

15. Why Choose VSP? • Credibility! Agencies are familiar—makes the presented conclusion more trustworthy • User friendly!

16. VSP’s Role Are there adequate data to make defensible risk management decisions? • Over 200 sample size calculations needed • Both soil and soil gas • Soil gas at both 5 and 15 ft bgs • Both 1x10-6 and 1x10-5 risk goals • Sample size calculations conducted retrospectively for the primary risk drivers identified in the risk assessment

17. VSP Validated DQA Approved! • DQA results ultimately led to satisfactory conclusion and approval of the HHRA after a six-year process Mclam submits DQA Air monitoring HHRA requested 2000 Mclam prepares baseline HHRA 2005 Excavation begun 1988 Multi-agency team Convened to weight potential future issues 2003 Mclam submits 1st draft of Supplemental HHRA 2008 HHRA with DQA approved! 2011 Excavation completed 2000

18. How Did VSP Do It?

19. Identify Primary Risk Drivers Greater than 50% of risk or hazard • Soil: benzo(a)pyrene, cadmium, chromium, ethylbenzene, lead, naphthalene, TPH and vanadium • Soil Gas: benzene, 1,3-butadiene, chloroform, ethylbenzene, and 1,2,4-trimethylbenzene

20. Identify Input Parameters • Site-specific screening levels • Standard deviations • Decision error rates • 85-95% confidence correctly determining area is clean • 15-25% chance incorrectly determining area is clean

21. Compare Average to Fixed Threshold • Known Input Parameters: • Distribution • Standard deviation • Unknown Input Parameters: • Desired confidence • Desired width of gray region

22. Compare Average to Fixed Threshold VSP’s report view shows results given a variety of Type I, II error rates and MDDs!

23. Report View

24. Report View

25. Sensitivity Analysis

26. What VSP Unmasked Two areas showing lead, benzene and ethylbenzene did not have enough samples to make defensible risk conclusions The areas were targeted for further action

27. Pros Of Using VSP • More defensible results • Many formulas included for many different sampling needs • Reviewers trust the brand • User-friendly for the average person • Don’t need to be a statistician • Don’t need to know programming to get program to do what you want • Huge cost savings on pricey statistical software

28. Case Closed