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2. Groundwater Monitoring Activities Teichert's permit requires a minimum of 10 wells to be located around the general perimeter of the permitted mining area for quarterly groundwater level monitoring. In addition, the permit requires 5 wells(two upgradient from the project site, two downgradient from the project site, and I on site) for groundwater quality monitoring. Groundwater quality monitoring shall include, at a minimum, general mineral analyses and nitrate. Wells used for domestic purposes shall also be tested for bacteria. The permit does not specify a frequency for groundwater quality monitoring activities. Since the inception of the monitoring program in 1994 and through 2009, groundwater quality sampling was conducted on a quarterly schedule together with groundwater level measurements. Groundwater quality monitoring was reduced to a semi-annual schedule in 2010. The required reporting frequency of monitoring results is annual. The wells for the monitoring network were selected based on a reconnaissance groundwater investigation conducted by LSCE in 1991 and 1992 (LSCE, 1992). Results indicated that the depth to groundwater ranged between 80 feet beneath the valley floor to the northeast and 250 feet beneath the mountain flanks to the southwest. In addition, a confining clay was identified beginning at an approximate depth of 250 — feet beneath the Lone Tree 1 Mining phase that appeared to divide the underlying aquifer into shallow and deep zones. This clay is most likely the Corcoran Clay Member of the Tulare Formation, which has been reported to extend beneath much of the San Joaquin Valley, including the present monitoring network area(Hotchkiss, 1972). Further, the investigation indicated that the direction of groundwater flow in the shallow zone was to predominantly the southeast. The established monitoring network presently consists of 7 shallow wells, 6 deep wells, and one composite well for a total of 14 network wells(see Figure 2)3. All 14 wells have been used for water level monitoring. However, port access at the Granite#3 well has been difficult and measurements have generally not been obtained since 2007. Also, instrumentation used for water level measurements has been obstructed at a depth of about 100 feet(bgs)in the irrigation well 4S/6E-6AL Therefore, regular quarterly groundwater level measurements are typically obtained from 12 wells. The established groundwater quality network consists of 2 wells upgradient from the Vernalis plant(Hall and Faulkner domestic wells), I well onsite(South Tracy #3 production well),and 2 downgradient wells (Granite#3 and Brown's New production wells). The monitoring network has experienced slight modifications in the past. For example, the South Tracy #3 production well was added to the water quality network in 2004 in lieu of the Brown's New well, which became inoperable in 2001 (due to the removal of the pump). With Granite's commencement of mining activities, the Brown's New well was equipped with a pump again and was incorporated back into the monitoring program in 2009 as a 3 As discussed in previous annual reports submitted on behalf of Teichert and also in Granite's approved Groundwater Monitoring Plan(LSCE,2009),Teichert's quarterly monitoring data record documents very stable groundwater quality conditions. The record also demonstrates that quarterly monitoring has produced redundant data in excess of what is needed for the groundwater conditions evaluation- ' At each well in the original monitoring network,the elevations of the ground surface and wellhead were surveyed _ by LSCE in November and December, 1994. Ground surface and wellhead elevations were referenced to several local bench marks(DWR, USBR,and San Joaquin County). The South Tracy#3,Granite#3,and Granite#4 wells were installed more recently,and presently, their reference point elevations are estimated based on ground surface elevations published on the U.S.Geological Survey topographic map for the area(Solyo Quadrangle,7.5 Minute Series). 2 �LLIUM r s s -Ai mNaLLTIN9 [NNM[[RS