APPENDIX H – Fremont Valley Preservation Project
August 19, 2013 Letter from GEI Consultants
P. 1-1 (p. 2371 of 6840) “However, the development and production of native water as indicated in the GMMMP of 114,000 acre feet per year (AFY) has the potential to cause significant unmitigated impacts to the Fremont Valley Groundwater Basin by causing subsidence, unknown supply impacts, and potentially irreversible groundwater quality degradation. …”However, this letter will address additional potential impacts, which could result if the implemented mitigation measures are not effective, or if available data proves inaccurate.”
p. 1-2 (p. 2372) “Additional future testing is required as described in the GMMMP to determine additional unknown data and address any unknown potential impacts, of native groundwater production beyond the available recharge of 10,500 to 12,500 AFY.”
p.1-2 (p. 2372) “Subsidence will likely continue to occur due to the historical pumping and the continued dewatering of the clays. Groundwater modeling results for this investigation suggest that the Koehn Lake Area has removed about 400,000 AF of water from storage due to dewatering of the clays. The Koehn Lake Area has lost a total of about 860,000 AF of water from storage during the period from 1958 to 2010 (GEI, 2012, p. 10-3)”
p.1-3 (p. 2373) …”prolonged native groundwater production significantly above the estimated native recharge of 15,000 to 17,000AF to the Koehn Lake Area (GEI , 2012, p. 6-11) could produce averse groundwater quality changes to the basin”
“groundwater production above the estimated native recharge of 15,000 to 17,000 AFY would likely decrease the current groundwater levels”…”Groundwater levels for wells used by others in the Koehn Lake Area would be affected to various degrees with higher water level declines closer to the native extraction wells and decreased drawdowns more distant. Other native water users could have increased pumping costs due to greater groundwater lift, and decreased well yields due to decreased well screen saturated thickness.” (p. 4-5, p. 2374) “The FVPP Properties are near active faults (Garlock and Cantil), and liquefaction due to ground motion is possible.”
P. 4-5 (p. 2375) “UNKNOWN POTENTIAL IMPACTS THAT CAN ONLY BE DETERMINED BY THE COLLECTION OF DATA BASED ON IMPLEMENTATION. …ACCORDINGLY, THE PROPOSED PRODUCTION OF 114,000 ACRE FEET PER YEAR (AFY) OF NATIVE WATER HAS THE POTENTIAL TO CAUSE SIGNIFICANT UNMITIGATED IMPACTS TO THE FREMONT VALLEY GROUNDWATER BASIN BY CAUSING SUBSIDENCE, UNKNOWN SUPPLY IMPACTS, AND POTENTIALLY IRREVERSIBLE GROUNDWATER QUALITY DEGRADATION. THESE POTENTIALLY SIGNIFICANT IMPACTS CANNOT BE MITIGATED AT THIS TIME GIVEN LACK OF DATA.
p. 1-5 (p. 2402) of the report itself “delivery of recovered groundwater to LADWP second LA Aqueduct system turn-in will be through a 72” diameter pipeline to above ground steel reservoir in SE corner of Sons Property. Pipelines will include facilities to tunnel beneath Highway 14 and the railroad”
Describes delivery of recovered groundwater to AVEK north feeder line – 72” diameter pipeline along Neuralia Road to Cal City Blvd., to Mojave/Randsburg Road. Also describes delivery to Edwards Air Force Base through a dedicated water transmission pipeline from Sons Property through California City by 24” pipeline. NO DELIVERY MECHANISMS DESCRIBED FOR DELIVERY OF RECOVERED GROUNDWATER TO CHINA LAKE NAWS.
p.1-7 (p.2404) “report may be supplemented by additional geologic research” Report does not address any surface or subsurface flows from north/northeast (El Paso Basin, IWV). Even though Appendix B by Soilswork Group presents a lot of information from studies describing flows through fractures coming from Sierra Nevada and showing connections from Mount Whitney through IWV to El Paso Basin and through “funnel” into Fremont Valley floor- no surface flows or subsurface flows from the northeast are addressed in the GEI Hydrology report.
Samda Appendix A Hydrogeologic Assessment of Fremont Valley by Earth Satellite Corporation p. 7 states “Mountainous areas receive the major part of the precipitation within the drainage basin, and the runoff from these areas forms a major contribution to the recharge in the alluvium” “Joints and faults in the basement complex may constitute channeling for groundwater movement from the mountains to Fremont Valley”
p. 16 reference to HydroSource in 1997 estimated average annual underflow from Jawbone Canyon at 4,000 to 10,000 AF
p.23 “Faulting plays a major role in controlling water production in this area. Specifically, the area south of the Cantil Fault will not be productive because of a relatively shallow depth to bedrock”
Beacon EIR Appendix J, p.3.3 “from the northeast of Koehn Lake – flows of water down the valley from the northeast as indicated by groundwater level contours. This water comes from mountain-front runoff into the valley through ephemeral stream drainages. (Koehler, 1977)”
p. 4-5 (P. 2419) “2012 Groundwater levels and hydrographs have rebounded by 50 ft. and 100 ft. on south side of Cantil Fault – rebounded about half of original 1958 levels”
Samda , Appendix A by Earth Satellite Corporation. 6 states that since farming discontinued in the 1980s “water levels have risen 5 to 7 feet per year (hydrgraphs in Appendix D of Samda report)”
p. 5-12 (p. 2449) future water demand for California City CSD is 12,655 AFY. Beacon will need 304 AF for construction and 15 AFY for operations.
p. 6-2 (P. 2456) presents a chart (Table6.4.1a) of estimates of recharge from precipitation from various studies – showing a range of recharge from 3,300 AFY to 56,000AFY.
p. 6-10 (p. 2459) shows a chart (Table 6.4.2) of estimates of recharge from change to storage ranging from 9,000 AF to 30,113 AF based on period from 1958 to 2010.
p. 10-1 (p. 2513) “Near active faults (Garlock and Cantil Faults) liquefaction due to ground motion is possible”
10-2 and 10-3 (p. 2514, 2515) “recovered water may need TDS and arsenic treatment – treated at individual wellheads”
p.10-3 (p. 2515) “Subsidence will likely continue to occur due to historical pumping and the continued
dewatering of the clays.” “The Koehn Lake Area has lost a total of about 860,000 AF of water from storage during the period from 1958 to 2010.” “The Project is not expected to produce subsidence due to lowering of the groundwater levels provided the Project does not extract groundwater beyond banked water amounts.”
Samda Appendix A p. 18 states there is “15,318 to 19, 113 AF net excess of water available for extraction in excess of usage for all of Fremont Valley.”
Samda Appendix A p.11 “The extraction of 10,000 AF annually should not exceed the natural recharge of the basin or result in overdraft” WHAT ABOUT THE EXTRACTION OF 114,000 AF ANNUALLY?
p. 10-3 (p. 2515) “Koehn Lake Area has approximately 7,000,000 AF of groundwater in storage to a depth of about 600 ft. bgs.” “the Koehn Subunit has an estimated 4,500,000 AF of groundwater in storage to a depth of about 600 ft. bgs.”
Both Samda and Beacon agree that in 1976 the amount of water in storage above the depth of 500 feet was 2 million to 2.5 million AF and total of groundwater in storage in the valley was about 4 million AF. Both were quoting from J. T. Koehler, Groundwater in the Koehn Lake Area, Kern County, California (Appendix B in the Samda report (p. 95 of 275) How much has been added to storage since 1976 – does the data support the use of the 7,000,000 AF amount?
The section describing the groundwater model (Modflow) development there are many statements saying values were determined by trial and error during the calibration of the model. Just how exact is the model to be used to support the project? Is it normal to calibrate the model by trial and error?
(I NEED TO VERIFY THE REFERENCE FOR THE BEACON PROJECT. – IT IS IN MY NOTES, BUT I NEED TO FIND THE PAGES IN THE DOCUMENT. 3.3 AND 3.4 OR 33 AND 34 in Appendix J of Beacon document??)
Notes prepared for Eastern Kern County Resource Conservation District October 17-23, 2013
President Donna C. Thomas