REP03364

• Permit No: M1992069
• IBM Index Class Name: Report
• Doc Name: SOIL AND GROUNDWATER ABATEMENT REPORT AGGREGATE INDUSTRIES F STREET FACILITY
• Media Type: D
• Archive: No

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Ms. Connie Davis/Aggregate Industries - F S[ree[ Soil and Groundwater Abatement Re ort
Project Number 1001018 ~'nRAGON
July 6, ?001
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North End and South Wall Middle assessment samples in an effort to bracket the TEPH
contamination.
As also seen in Table 1, BTEX concentrations ranged from not observed above the
laboratory detection limits of 2 µg/Kg to approximately 3,194 µg/Kg while TEPH
concentrations ranged from approximately 4,283 to 4,611 mg/Ks in the two (2) waste soil
samples. The Class 7 Run soil sample was the fine soil material after processing the
impacted soil with the crusher while the Stockpile sample was unprocessed material. It
should be noted that the Stockpile sample was collected approximately two (2) days after the
impacted soil had been excavated from the spill area.
The Tier I RBSLs for the leachate to groundwater ingestion exposure pathway and TPH
' Threshold soil standards, as published in Section 6.3 of the Storage Tank Regulations
(7CCR IIOI-14), are also summarized in Table 1. As seen from Table 1, the TEPH
concentrations observed in the West Wall North End. Bottom ~1. South Wall Middle, Class
' 7 Faun and Stockpile soil samples exceeded the TPH Threshold standard. The BTEX and
P.4H concentrations observed in the soil samples analyzed from the site did not exceed the
Tierl RBSLs.

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4.2 Groundwater Sample Results
One (I) groundwater sample was collected from the abatement excavation on May ] 7, 2001
to document the concentrations of petroleum hydrocarbons which were present in the
groundwater in the abatement excavation while one (1) groundwater sample was collected
from a downgradient mining dewatering trench on May 1~. 2001 to confirm that the
dewatering trench had not bee^ significantly impacted by petroleum hydrocarbons. The
laboratory results for the groundwater samples collected from the site are summarized in
Table 2 in Appendix B of this report. As seen Yrom Table 2, BTEX were not observed above
the laboratory detection limits of 0.5 micrograms per liter (ug/L) in the Discharge Point 2
and Abatement Pit samples with the exception of xylenes which were observed at a
concentration of 47 µg/L in the Abatement Pit sample collected on May l7, 2001. TEPH
wa:; not observed above the laboratory detection limit of 0.~ milligrams per liter (mg/L) in
the Discharge Point 2 groundwater sample while TEPH was observed at a concentration of
126 mg/L in the groundwater sample collected from the abatement excavation on May 17,
_'001.
' The: Ivtaximum Contaminant Levels (MCLs) for BTEX are also summarized in Table 2. As
seen from Table 2, the MCLs for BTE~C are d.0; 1.000; 680 and 10.000 µg/L, respectively.
' Those standards are the statewide interim organic pollutant standards published in '`The
Basic Standards for Ground Water" Regulation 41, (~ CCR 1002-41). It should be noted
that TEPH is not regulated by a numeric standard in Colorado at this time. The BTEX
' concentrations observed in the eroundwater samples collected from the dewatering trench
and abatement excavation in May ~OOI did not exceed the MCLs. The groundwater sample
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