Post on 09-May-2020
(
(
((
(
((
(
((
(
(
(
(
(
(
(((((
(
(
(
(
(
(
(
(
(
(
((
(
(
(
(
(((
(
(
(
(
((
(
(
(
((
(((
(
(
(
(
((
(
(
((
((
((
(
((
(
((
((
(((
!
!
!
!!
!
!
!
!!
!
!
!
!
!
!
!
!
!
!
!! !!
!
!
!
!
!
!!
!
!
!
!
!
!
!!
! !!
!
!
!
!
/
//
)Ñ
//
/
/
/
)Ñ
)Ñ
)Ñ
/
/
/
>
<<
>
>
>>
>
>>
>
>
>
>
>
<
>>>>>
>
>
>
<>
>
.
. .. .
. ..
.. . .
.
.
.
.
.
.
..
.
..
...
.
...
.
.
..
.
..
..
.
..
...
.
..
.
.
.
.
.
.
...
.
.
..
..
....
..
.
..
..
..
.
.
..
..
..
..
..
..
..
..
....
.
.
..
.
.
>
>
>
>
>A
A
A
A
A
>
Mou
ntai
n V
iew
Rd
Sum
mer
set R
d
Thompson Rd
Santa Fe Ave
Hwy 58
Desert View Dairy
Approximate limit of saturated alluvium
Upper Aquifer
Bedrockexposed at
ground surface
26-65ND/ND
26-66ND/1.5
MW-23C20.5/20.7
MW-31CND/ND
MW-55C0.47/ND
MW-68CND/ND
MW-90CND/ND
MW-91CND/ND
23-130.66/1.2
23-153.6/3.8
23-193.0/3.2
23-242.7/2.1
23-250.77/1.4
23-260.51/ND
23-301.9/3.2
23-320.76/1.7
24-022.9/2.9
24-083.3/3.2
24-101.7/2.5
25-073.6/3.4
25-103.3/3.3
25-141.7/1.5
26-493.5/3.4
27-032.2/2.4
27-082.7J/1.7J
27-212.3/1.927-36
2.2/1.927-382.9J/1.6J
27-390.88/1.3
27-402.1/1.9
27-461.3/2.1
34-010.32/ND
34-34ND/ND
36-241.9/1.8
BGS-462.0/1.8
#
BGS-491.4/1.7
CA-MW-204D62.4/62.1
CA-MW-312D23.4/21.5
CA-MW-31354.7/49.3
CA-MW-315D75.8/72.8
CA MW 317S
CA-MW-405D72.7/71.6 CA-MW-411S
51.5/47.7
CA-MW-412D56.6/47.1
CA-MW-501S40.6/44.4
CA-MW-506D52.5/56.7
CA-MW-508S15.3/13.1
CA-MW-510S10.3/8.8
DW-014.3/3.8
DW-020.31/ND
DW-031.5J/1.0J
MW-06134/115
MW-1330.8/30.3
MW-14A57.6/52
MW-21BND/ND
MW-21B15.1/5.6
MW-23B42.4/41.2MW-28A
3.0/3.8MW-28B48.9/46.3
MW-2911.8/12.3 MW-30B1
4.5/6.8MW-30B26.6/6.7
MW-3115.5/15.9
MW-32B13.5/3.6MW-32B2
ND/ND
MW-32S2.1/2.5
MW-38A64.5/58.1
MW-41S10.3/10.1
MW-42B130.7/30.6
MW-42B243/43.4
MW-4312.8/12.7
MW-44A1.9/2.1
MW-44B3.3/4.3
MW-45A40.3/39MW-45B2.0/2.1
MW-477.0/6.4
MW-49A4.9/4.2
MW-49S3.4/3.8
MW-50A4.6/3.8MW-50B
2.6/2.8
MW-50S13.5/13.5
MW-541.6/2.0
MW-55AND/ND
MW-55BND/ND
MW-55S2.4/3.4
MW-566.4/6.3
MW-572.9/2.6
MW-58
MW-592.1/1.8
MW-611.4/1.5
MW-62A19.7/17.1MW-62BND/ND
MW-630.73/1.6
MW-64A0.71/ND
MW-66A2.6/2.7
MW-68D5.0/5.7
MW-68S0.35/2.2
MW-69D1.7/2.7
MW-69SND/2.9J
MW-70D4.6/4.8
MW-70S1.6/3.0 MW-71D
2.6/2.6
MW-71S2.4/2.4
MW-72DND/1.0
MW-72S7.2/6.3
MW-75D1.4/1.6
MW-76D0.92/1.1
MW-76S3.7/3.5
MW-79DND/ND
MW-79S5.5/5.5
MW-80D1.0/1.5
MW-80SND/ND
MW-81S0.84/ND
MW-82S1.4/2.1
MW-83D2/2.3
MW-83S1.8/2.4
MW-84DND/ND
MW-84S1.9/3.4
MW-85D0.29/ND
MW-85S0.54/1.4
MW-86D1.2/1.4
MW-86S5.3/5.7
MW-87D1.5/1.6
MW-87S2.1/2.3
MW-88DND/ND
MW-88S5.5/5.2
MW-89D0.74/1.2
MW-89S2.6/3.0
SC MW 06S
SC-MW-07D0.98/ND
SC-MW-07S1.0/1.3
SC-MW-08D1.6/2.1
SC-MW-08S1.4/2.2
SC-MW-09S15.6/11.2
SC-MW-10S1.9/2.3
0.45/3.6*
EX-0416.1/17.1
EX-051.1/3.8
EX-090.52/1.2
EX-100.82/1.1
EX-1546.6/42.6
EX-1641.3/38.2
EX-2043.5/41
EX-0113.7/14.7
EX-0210.0/10.3
EX-0322.3/24.2
EX-17ND/ND
EX-2142.9/38.1
EX-2245.4/39.5
EX-235.7/5.3
EX-242.5/2.1
IN-01NS
IN-02NS
IN-03NS
IN-04NS
IN-05NS
24-093.2/3.2
25-162.3/2.7
25-173.2/2.7
Acacia St
Alcudia Rd
Manacor Rd
Serra
Rd
Alcudia Rd
Serra
Rd
Approximate 50 µg/L outlineof Cr(VI) or Cr(T)concentrations in Upper Aquifer, October-November 2010
Approximate 10 µg/L outline of Cr(VI) or Cr(T) concentrations in Upper
23-22NS
Hinkley School
(
(
(
(
(
(
(
((
(
((
((
(
((
(
(
((
((
((((
((
((!
!
!
!
!
!
!
!
! !
!
!
!
!
!
!!
!
!
! !!
!
)Ñ
>
>
>
.
.
.
.
.
.
.
.
.
.
.
.
..
.
..
..
+
.
.
.
.
.
..
..
..
..
..
..
..
.
.
..
..
... .
..
.
)Ñ
.
.
Community Blvd
Fair
View
Rd
PG&E Compressor Station
Freshwater Supply WellPGE-140.44/ND
SC-MW-16C1.2/ND
02-02A0.33/ND
02-05ND/ND
35-04ND/ND
CA-MW-317S8.7/8.2
MW-0326.6/22.9
MW-0441.2/39.5
MW-050.73/ND
MW-11B1660/1560
MW-1632.7/31.3
MW-17113/110
MW-201650/1500
MW-400.27/ND
MW-460.66/ND
MW-67A1.4/1.4
MW-73D0.85/1.1
MW-73S0.79/ND
MW-74D2.3/2.3
MW-77D1.3/1.7
MW-77S1.0/1.3
MW-78D1.8/1.9
MW-78S0.77/ND
PT2-MW-10555/506
SA-MW-16S401/338
SA-MW-17S221/177
SA-SM-01S1120/1030
SA-SM-02S2230/2040
SC-MW-01D1.1/1.3
SC-MW-01S0.54/ND
SC-MW-02D228/226
SC-MW-02S0.63/ND
SC-MW-03D411/371
SC-MW-03S6.9/6.7
SC-MW-04D9.5/9.1
SC-MW-04S0.7/ND
SC-MW-05D1.4/1.5
SC-MW-05S0.93/ND
SC-MW-06D1.3/1.5
SC-MW-06S0.91/ND
SC-MW-11DND/ND
SC-MW-11S0.38/ND
SC-MW-12S17.1/16.7
SC-MW-13S25.2/21.2
SC-MW-14D1.0/ND
SC-MW-14S1.3/1.1
SC-MW-15D1.6/1.5
SC-MW-15S1.4/1.3
SC-MW-16D1.0/1.5
SC-MW-16S0.84/1.8SC-MW-21S
334/292SC-MW-26D
1540/1480
SC-MW-38D177/157
SC-MW-38S7.9/6.0
X-1162.8/60.2
MW-36NS
MW-74SNS
X-16185/171
( ) ( ) ppAquifer, October-November 2010
Approximate outlne of Cr(VI) or Cr(T) in Upper Aquifer exceeding backgroundvalues of 3.1 and 3.2 µg/L, respectively, October-November 2010
\\ZINFANDEL\PROJ\PACIFICGASELECTRICCO\HINKLEYREMEDIATIONPROJECT\GIS\MXDS\MP_MONITORINGPROGRAM\2010\MP_CRT_DISTRIBUTION_2010OCTNOV_REV03.MXD GMOON 2/10/2011 13:41:14
FIGURE 4HEXAVALENT AND TOTAL CHROMIUM CONCENTRATIONSOCTOBER-NOVEMBER 2010AND INTERPRETED MAXIMUM PLUMEOUTLINE IN UPPER AQUIFER
SITE-WIDE GROUNDWATER MONITORING PROGRAMPACIFIC GAS & ELECTRIC CO. COMPRESSOR STATIONHINKLEY, CALIFORNIA
Notes:1. Chromium results are shown for all site-wide Groundwater Monitoring Program wells sampled in the October-November 2010 sampling event. In addition, October-November results for selected In-situ Reactive Zone (IRZ) monitoring wells are shown for plume mapping. See Appendix E for the chromium results for all IRZ monitoring wells sampled in October-November 2010.
2. The concentration contours are based on chromium results from the groundwater monitoring wells. Results for long-screen (>25 feet) supply or extraction wells, shown in italics, and lower aquifer wells (gray shade labels) were not used for contouring.
3. Concentration contours represent the maximum extent of either Cr(VI) or Cr(T) at any depth within the Upper Aquifer based on monitoring well data. Some chromium results for wells within the 50, 10, and 3.1/3.2 chromium contours are less than those concentrations.
4. The 3.1/3.2 ug/L Cr(VI)/Cr(T) plume outline shown in the northeast, Summerset Road area, is inferred based on available data from all monitoring wells sampled in this area in August and October-November 2010 sampling events. As required by the Water Board, PG&E is installing additional monitoring wells to improve delineation of the chromium plume boundaries in this area.
±0 500 1,000 1,500
Feet
LEGEND
. Groundwater Monitoring Well> Domestic Supply Well<
Agricultural Supply Well+ Other Supply Well/ Active Groundwater Extraction Well)Ñ Inactive Extraction or Multi-Use Well
A Freshwater Injection Well
PG&E Property
( < 3.1 μg/L or ND! 3.1 - 10 μg/L! 10 - 50 μg/L
! 50 - 100 μg/L! 100 - 1,000 μg/L! > 1,000 μg/L
Groundwater Cr(VI) Concentrations in Monitoring Wells
REVISED 2/10/2011
Cr(VI) = Hexavalent ChromiumCr(T) = Total Dissolved ChromiumND = Not Detected; NS = Not SampledJ = Analyte was present in the sample but the laboratory reported concentration is qualified as estimated by data validation because one or more quality control criteria were not met
MW-611.99/2.04
Well IDCr(VI)/Cr(T) concentrations in micrograms per liter (µg/L); maximum of primary and duplicate samples
* = The Cr(T) result initially reported for well MW-58 during fourth quarter 2010 (shown on this figure) was rejected due to data quality issues related to the laboratory analysis, and is not representative of Cr(T) concentrations in the aquifer at this location. The same sample was re-analyzed for Cr(T) and the second result was 1.3 μg/L.