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<br />,~ <br />~ <br />,-- <br />r: <br />[: <br />r: <br />r-: <br />r~ <br />[-' <br /> <br />Limited Phase II Environmental Site Assessment <br />8-Acre Property, Fairhaven Memorial, Santa Ana, California <br /> <br />The State of California DTSC has also developed threshold levels for various pollutants in soil. <br />The total threshold limit concentration (TTLC) and soluble threshold limit concentration (STLC) <br />are used to determine whether excavated soil would be classified as a hazardous or non- <br />hazardous waste for disposal purposes. The detected concentrations of pesticides in the soil <br />samples collected and analyzed for pesticides were compared to the TTLC thresholds established <br />by the DTSC. None of the detected concentrations of pesticides exceeded their respective <br />TTLCs nor were high enough to warrant soluble (STLC) analysis. <br /> <br />Metals in Soil: Varying concentrations of metals were detected in the soil samples collected and <br />analyzed for metals. The PRGs for residential and industrial settings for arsenic are 0.062 and <br />0.25 mg/kg, respectively. Background concentrations of arsenic found in western United States <br />soils (non-contaminated sites) range from 0.10 to 97 mg/kg (Shacklette and Boerngen, Element <br />Concentrations in Soils and Other Surficial Materials of the Conterminous United States, USGS, <br />1984). The USEP A states that generally they do not require cleanup below natural background <br />levels. In light of this fact and in our experience, regulatory agencies typically consider the use <br />of local or regional background concentrations as the threshold concentration for requiring <br />further investigation or remediation. All of the analyzed soil samples detected arsenic <br />concentrations above the PRGs for residential and industrial settings and all of the detected <br />concentrations are within the range of naturally occurring background concentrations for arsenic <br />in western United States soils. <br /> <br />In addition, the levels of metals detected were compared to total threshold limit concentration <br />levels established by the DTSC. The TTLC is used to determine whether excavated soil would <br />be classified as a hazardous or non-hazardous waste for disposal purposes. STLC and TTLC <br />levels for metals are listed in Table 2. Lead was detected in the O.5-foot sample from boring HA- <br />6 at a level that warranted soluble (STLC) analysis. The additional STLC analysis revealed non- <br />detect levels of soluble lead. Metal concentrations detected for all of the other samples analyzed <br />for metals did not exceed their respective TTLC levels and were not high enough to warrant <br />soluble (STLC) analysis. <br /> <br />CONCLUSIONS <br /> <br />Based on the soil sampling and analysis for this Phase II ESA, the following has been concluded: <br /> <br />. The levels of pesticides detected in soil samples collected from the subject property do not <br />exceed PRG or TTLC thresholds established by the USEP A and DTSC. <br /> <br />· The levels of metals identified in the soil samples collected from the subject property were <br />within the published background ranges for metals in western United States soils. <br /> <br /> <br />· Lead was detected in the 0.5-foot samples collected from boring HA-6 at a level that <br />warranted soluble (STLC) analysis. The additional STLC analysis revealed non-detect levels <br />of soluble lead in that soil sample. Detected levels of metals in the other soil samples did not <br />exceed PRG or TTLC thresholds established by the USEP A and DTSC. <br /> <br />-' <br /> <br />r <br /> <br />Rincon Consultants <br /> <br />351 A "77 0 <br />