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e
<br />dp,
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<br />Department of Water resources.
<br />east of the site on El Dorado
<br />known water wells within a one -
<br />Figure 3.
<br />The closest well to the site is due
<br />treet. The approximate locations of
<br />ile radius of the site are plotted on
<br />Previous investigations at thl facility snow that the unsaturated
<br />soils beneath much of the site consist primarily of clays (CL/CH)
<br />from surface to approximately 26 feet below grade with a zone of
<br />elastic silt (MH) and clay (CL) to a depth of 36 feet, the maximum
<br />depth of the unsaturated zone. However, in the central portion of
<br />the site, roughly coincident with the area of the forner tank
<br />excavation, the site is comprised largely of sands. A portion of
<br />this material may be fill from ff-site, placed in the excavation to
<br />a depth of approximately 12 feot below grade. From approximately 12
<br />to 26 feet below grnda, the native isaterial is largely sand as
<br />indicated by tho lots from bord..ngs SB3, SD4, SB9, VP1 and VP2.
<br />The saturated zone from approximately 35 feet to at least 50 feet
<br />below grade is comprised of intercalated clays, silts and sands.
<br />This zone appears to be under, some degree of confinement and is'.,'
<br />clearly separated hydraulically from the nearby surface water (deep
<br />water channel).
<br />Current depth to groundwater
<br />below grade. Groundwater gra
<br />northeast at 0.005 feet per f
<br />4.0 SUMliARY OF PF'EVIOUS
<br />the site is approximately 35 feet
<br />t at the site is toward the north --
<br />or 26 feet per mile (Figure 5).
<br />TIONS
<br />Previous. as.sssmentE. at the facility have included : 1) ERM West
<br />(September 1989), 2) Kleinfel er, Inc. (May and June, 1990), 3)
<br />Lesdshill-Herkenhoff, Inc. (October 1990), and 4) RESN,. Industries
<br />(May, 1991). These assess ents have identified a petroleum
<br />hydrocarbon plume associated with the previously excavated product
<br />storage tanks at the facility.
<br />In September 1989, ERM - west o Sacramento, California, conducted a
<br />Phase I Environmental Site Asse sment which included a site visit and
<br />a. survey of surrounding land u es.
<br />A second phase of investigation included a soil gas survey around the
<br />former storage tank area and pump islands by Kleinfelder, Inc. Soil -
<br />gas samples were collected from 15 locations at the site and analyzed
<br />for total hydrocarbons, and benzene, toluene, ethylbenzene and
<br />xylenes by gas chromatography. Findings from this investigation
<br />determined that petroleum hydrocarbon concentrations were detected in
<br />soil -gas from the area where he former tanks had been excavated.
<br />Petroleum hydrocarbons were also detected in soil -gas samples up to
<br />60 r:.r i,:est and 50 feet so tha:ast of the tank excavation and
<br />ad' ;:': 7 the underground piping which leads from the tank area to
<br />t'. :y pump island. A detailed summary of findings can be
<br />f leinfelder's Soil -Gas and Storage Tank Assesflment report
<br />da,: 14, 1990.
<br />Lobar Paint Pt parry - 475
<br />H20W.P7V1.TLP
<br />2
<br />nr
<br />..:!I
<br />i x
<br />e
<br />dp,
<br />•``J 1
<br />Department of Water resources.
<br />east of the site on El Dorado
<br />known water wells within a one -
<br />Figure 3.
<br />The closest well to the site is due
<br />treet. The approximate locations of
<br />ile radius of the site are plotted on
<br />Previous investigations at thl facility snow that the unsaturated
<br />soils beneath much of the site consist primarily of clays (CL/CH)
<br />from surface to approximately 26 feet below grade with a zone of
<br />elastic silt (MH) and clay (CL) to a depth of 36 feet, the maximum
<br />depth of the unsaturated zone. However, in the central portion of
<br />the site, roughly coincident with the area of the forner tank
<br />excavation, the site is comprised largely of sands. A portion of
<br />this material may be fill from ff-site, placed in the excavation to
<br />a depth of approximately 12 feot below grade. From approximately 12
<br />to 26 feet below grnda, the native isaterial is largely sand as
<br />indicated by tho lots from bord..ngs SB3, SD4, SB9, VP1 and VP2.
<br />The saturated zone from approximately 35 feet to at least 50 feet
<br />below grade is comprised of intercalated clays, silts and sands.
<br />This zone appears to be under, some degree of confinement and is'.,'
<br />clearly separated hydraulically from the nearby surface water (deep
<br />water channel).
<br />Current depth to groundwater
<br />below grade. Groundwater gra
<br />northeast at 0.005 feet per f
<br />4.0 SUMliARY OF PF'EVIOUS
<br />the site is approximately 35 feet
<br />t at the site is toward the north --
<br />or 26 feet per mile (Figure 5).
<br />TIONS
<br />Previous. as.sssmentE. at the facility have included : 1) ERM West
<br />(September 1989), 2) Kleinfel er, Inc. (May and June, 1990), 3)
<br />Lesdshill-Herkenhoff, Inc. (October 1990), and 4) RESN,. Industries
<br />(May, 1991). These assess ents have identified a petroleum
<br />hydrocarbon plume associated with the previously excavated product
<br />storage tanks at the facility.
<br />In September 1989, ERM - west o Sacramento, California, conducted a
<br />Phase I Environmental Site Asse sment which included a site visit and
<br />a. survey of surrounding land u es.
<br />A second phase of investigation included a soil gas survey around the
<br />former storage tank area and pump islands by Kleinfelder, Inc. Soil -
<br />gas samples were collected from 15 locations at the site and analyzed
<br />for total hydrocarbons, and benzene, toluene, ethylbenzene and
<br />xylenes by gas chromatography. Findings from this investigation
<br />determined that petroleum hydrocarbon concentrations were detected in
<br />soil -gas from the area where he former tanks had been excavated.
<br />Petroleum hydrocarbons were also detected in soil -gas samples up to
<br />60 r:.r i,:est and 50 feet so tha:ast of the tank excavation and
<br />ad' ;:': 7 the underground piping which leads from the tank area to
<br />t'. :y pump island. A detailed summary of findings can be
<br />f leinfelder's Soil -Gas and Storage Tank Assesflment report
<br />da,: 14, 1990.
<br />Lobar Paint Pt parry - 475
<br />H20W.P7V1.TLP
<br />2
<br />..:!I
<br />i x
<br />'I
<br />e
<br />dp,
<br />•``J 1
<br />Department of Water resources.
<br />east of the site on El Dorado
<br />known water wells within a one -
<br />Figure 3.
<br />The closest well to the site is due
<br />treet. The approximate locations of
<br />ile radius of the site are plotted on
<br />Previous investigations at thl facility snow that the unsaturated
<br />soils beneath much of the site consist primarily of clays (CL/CH)
<br />from surface to approximately 26 feet below grade with a zone of
<br />elastic silt (MH) and clay (CL) to a depth of 36 feet, the maximum
<br />depth of the unsaturated zone. However, in the central portion of
<br />the site, roughly coincident with the area of the forner tank
<br />excavation, the site is comprised largely of sands. A portion of
<br />this material may be fill from ff-site, placed in the excavation to
<br />a depth of approximately 12 feot below grade. From approximately 12
<br />to 26 feet below grnda, the native isaterial is largely sand as
<br />indicated by tho lots from bord..ngs SB3, SD4, SB9, VP1 and VP2.
<br />The saturated zone from approximately 35 feet to at least 50 feet
<br />below grade is comprised of intercalated clays, silts and sands.
<br />This zone appears to be under, some degree of confinement and is'.,'
<br />clearly separated hydraulically from the nearby surface water (deep
<br />water channel).
<br />Current depth to groundwater
<br />below grade. Groundwater gra
<br />northeast at 0.005 feet per f
<br />4.0 SUMliARY OF PF'EVIOUS
<br />the site is approximately 35 feet
<br />t at the site is toward the north --
<br />or 26 feet per mile (Figure 5).
<br />TIONS
<br />Previous. as.sssmentE. at the facility have included : 1) ERM West
<br />(September 1989), 2) Kleinfel er, Inc. (May and June, 1990), 3)
<br />Lesdshill-Herkenhoff, Inc. (October 1990), and 4) RESN,. Industries
<br />(May, 1991). These assess ents have identified a petroleum
<br />hydrocarbon plume associated with the previously excavated product
<br />storage tanks at the facility.
<br />In September 1989, ERM - west o Sacramento, California, conducted a
<br />Phase I Environmental Site Asse sment which included a site visit and
<br />a. survey of surrounding land u es.
<br />A second phase of investigation included a soil gas survey around the
<br />former storage tank area and pump islands by Kleinfelder, Inc. Soil -
<br />gas samples were collected from 15 locations at the site and analyzed
<br />for total hydrocarbons, and benzene, toluene, ethylbenzene and
<br />xylenes by gas chromatography. Findings from this investigation
<br />determined that petroleum hydrocarbon concentrations were detected in
<br />soil -gas from the area where he former tanks had been excavated.
<br />Petroleum hydrocarbons were also detected in soil -gas samples up to
<br />60 r:.r i,:est and 50 feet so tha:ast of the tank excavation and
<br />ad' ;:': 7 the underground piping which leads from the tank area to
<br />t'. :y pump island. A detailed summary of findings can be
<br />f leinfelder's Soil -Gas and Storage Tank Assesflment report
<br />da,: 14, 1990.
<br />Lobar Paint Pt parry - 475
<br />H20W.P7V1.TLP
<br />2
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