Co-Located Chemical Sampling Planned Sampling Approach

Laura RaineyDepartment of Toxic Substances ControlOctober 12, 2010

Goals for Co-located Chemical Sampling Effort

Opportunity to obtain additional chemical data (co-located with radionuclide data) to assist in identifying key chemical contaminants that may drive cleanup decisions.

Takes advantage of all the additional information that EPA has obtained to target sampling (EPA Historical Site Assessments, Gamma Scanning Data, Geo-physical logging, former worker interviews, aerial photography analysis).

Key Differences

The Agreement in Principle envisions “split” sampling Decision made to co-locate chemical sampling

due to chemical sampling needs: Amount of soil volume needed due to

differences in radionuclide and chemical analytical method needs

Chemical sample interval based on RFI/RI approach and utilizes field screening and visual observations

Key Differences: Rad vs. Chemical Sampling

Amount of soil volume needed Volume required dependent on EPA chemical

analytical method requirements Sample collection and handling

Homogenization over depth interval (rad) vs. discrete sampling (chemical)

Chemical analyses utilize EPA analytical methods Chemical sample depth interval

Selection based on RFI/RI approach Discrete depths selected based on site features

(including excavations/fill areas), screening and visual field observations

Sampling Intervals

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Table of Analytes--Primary Analyses (anticipated to be performed on all collected soil samples):

Analysis EPA Method (unless otherwise listed)

Volatile Organic Compounds 8260B

Metals 6010/6020B

Mercury 7471A

Chromium VI 7196A or 7199

Semivolatile Organic Compounds 8270C

Polycyclic Aromatic Hydrocarbons 8270 SIM

Perchlorate 314.0

Polychlorinated Biphenyls 8082

Fluoride 300.0/9056A

Dioxin/Furans 1613B

Total Petroleum Hydrocarbons (gas/oil/diesel) 8015B

Percent Moisture 160.3

Table of Analytes--Secondary Analyses (performed on selected soil samples):

Analysis EPA Method (unless otherwise listed)

1,4-Dioxane 8260B SIM

Formaldehyde 8315A

Hydrazine 8315A

n-Nitrosodimethylamine 1625C

Energetics 8330A

Cyanide 9012B

pH 9045C

Alcohols 8015B

Terphenyls 8015B

Glycols 8015B

Methyl Mercury 1630

Organic Tin NOAA Status and Trends

Asbestos 600/R-93/116

Pesticides 8081A

Herbicides 8151

DTSC Oversight

DTSC will: Periodically observe sampling in field to

ensure procedures are being followed Participate in quality audits of the

laboratories Obtain quality control split samples to

be sent to DTSC laboratory

Conclusions

Chemical co-located sampling will be a significant input to DTSC for purposes of determining the nature and extent of residual chemical contamination in Area IV and the Northern Undeveloped Land