Qualitative vs. quantitative data: Controls on the accuracy of PID field screening in petroleum contamination assessment applications

Journal Article · Fri Sep 01 04:00:00 EDT 1995 · Ground Water

OSTI ID:122436

Luessen, M J; Allex, M K; Holzel, F R ^[1]

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1. ATEC Associates Inc., Cincinnati, OH (United States)

The use of photoionization detectors (PIDs) for field screening of soils for volatile organic contaminants has become a standard industry practice. PID screening data is generally utilized as a qualitative basis for selection of samples for laboratory analysis to quantify concentrations of specific contaminants of concern. Both qualitative field screening data and quantitative laboratory analytical data were reviewed for more than 100 hydrogeologic assessment sites in Ohio to evaluate controls on the effectiveness of field screening data. Assessment data evaluated was limited to sites at which the suspected contaminant source was a gasoline underground storage tanks system. In each case, a 10.0 eV (or greater) PID calibrated for benzene was used to screen soils which were analyzed for benzene, toluene, ethylbenzene and xylene (BTEX) by SW 846 method 8020. Controls on field screening which were evaluated for each site included (1) soil classification, (2) soil moisture, (3) weather conditions, (4) background levels, (5) equipment quality, (6) screening methodology, and (7) laboratory QA/QC. Statistical data analysis predictably indicated a general overestimate of total BTEX levels based on field screening (gasoline is approximately 25 weight percent BTEX). However, data locally indicated cases of both significant (i.e., more than an order of magnitude difference) over- and under-estimation of actual BTEX concentrations (i.e., quantitative laboratory data) by field screening data.

• OSTI ID: 122436
• Report Number(s): CONF-9510211--
• Journal Information: Ground Water, Journal Name: Ground Water Journal Issue: 5 Vol. 33; ISSN GRWAAP; ISSN 0017-467X
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
ACCURACY
CHEMICAL ANALYSIS
FIELD TESTS
MEASURING INSTRUMENTS
OHIO
OIL SPILLS
PETROLEUM PRODUCTS
SITE CHARACTERIZATION