1. Site Assessment Fundamentals Problems During Construction Panel Discussion and Forum Mayor’s Office of Housing 1 South Van Ness Avenue July 29, 2008

2. Due Diligence Site Assessment Main Issues Phase I Environmental Site Assessment Phase II Characterization – Soil and Groundwater Sampling Phase III Remediation – Remedial Soil Disposal – UST Removal Maher Ordinance – Articles 20 & 22A

3. EXPERIENCE TELLS US Presence of fill materials and elevated lead Underground Storage Tanks (USTs) Maher Ordinance Concerns Site Use Change – Especially Commercial/Industrial to Residential Requirement for Site Management Plan and/or long- term soil management

4. When is Lead an Issue? When TTLC total lead is above 400 ppm (In SF) When TTLC total lead is above 100 ppm, or STLC soluble lead and/or Federal TCLP soluble lead is above 5 ppm Excess soil for offsite disposal When TTLC total lead is over 50 ppm When STLC soluble lead is above 1.2 ppm / 5 ppm

5. 1906 Fire

6. Map of 1906 Fire

7. Maher Ordinance Area (Yellow)

8. Terminology TTLC (Total Threshold Limit Concentration) - the total metal concentration in the sample expressed in parts per million (ppm) STLC (Soluble Threshold Limit Concentration) - the California soluble metal test a.k.a. CAM WET reports soluble metal in milligrams per Liter or ppm, used to characterize soil for disposal only, should never be used to assess health risk

9. Terminology cont. PRG (Preliminary Remediation Goal) San Francisco Department of Public Health ESL (Environmental Screening Level) Regional Water Quality Control Board CHHSL (California Human Health Screening Level) California Department of Toxic Substances Control

10. What is a “Part per Million”? One automobile in bumper-to-bumper traffic from Cleveland to San Francisco One Kleenex tissue in a stack taller than the Empire State Building One pancake in a stack four miles high One inch in 15.8 miles One minute in 2 years One ounce in 31 tons

11. How “We” Can Help - Phase I ESA “You get what you pay for” - Perform subsurface investigation – depending on site location, Phase I issues, and proposed site use -Expertise and experience to evaluate results -Budget and profile excess soil disposal -Provide a “second opinion”

12. For More Information Contact: –David DeMent, PG, REA II (925) 938-1600 x109 ddement@erscorp.us Questions, Proposals, Second Opinions –www.erscorp.uswww.erscorp.us