South East Management Area
Table 3-3: Ground Water Quality in Selected Wells
Table 4
Avg TDS (#) 1 (mg/L)
Avg Pb (ug/L)
Avg Mn (mg/L)
Avg As (ug/L)
Well Name
Date Range
Agency
Well Use
602
IRWD
LF-2
Production
2016-2018*
0.42
0.51
22.3
IRWD
LF-1
Production
1961-2000
>500 (21)
IRWD
LF-4
Production
1993-2000
>500 (12)
IRWD
LF-5
Production
1997-2001
>500 (5)
IRWD
LF-3
Production
1991-1998
>500 (12)
IRWD
LF-7
Production
1994-2001
<500 (12)
City of Orange
N/A
N/A
N/A
N/A
N/A
N/A
N/A
ETWD
N/A
N/A
N/A
N/A
N/A
N/A
N/A
1 # = Number of Samples * LF-2 Turned Offline in February 2018
3.2.5 Land Subsidence
Non-recoverable land subsidence has not been observed since 2015 in the South East Management Area (see Figure 3-6). The area is not susceptible to land subsidence given the following: 1. Minimal groundwater development exists in the South East Management Area. 2. Groundwater levels are stable or rising and have been for at least the last 10 years. 3. Low risk of future groundwater level declines due to limited planned groundwater production. As shown in Figure 3-6, the South East Management Area experienced between -0.05 and 0.05 feet of vertical displacement across years 2015 to 2020 with an accuracy of approximately 0.05 feet in data readings. Recently, as part of DWR's SGMA technical assistance to provide important SGMA- relevant data to Groundwater Sustainability Agency’s (GSAs) for Groundwater Sustainability Plan (GSP) development and implementation, DWR contracted with TRE ALTAMIRA, Inc. to provide vertical displacement estimates are derived from InSAR data that are collected by the European Space Agency (ESA) Sentinel-1A satellite.
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BASIN 8-1 ALTERNATIVE 2022 UPDATE
Appendix F - 217
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