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Mr. Mike Huggins
<br /> February 9, 2009 Groundwater Monitoring Plan
<br /> Page 6 of 8 Granite Construction Company,Vernalis Plant
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<br /> affect groundwater quality in the underlying aquifer system. However,the results of the groundwater
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<br /> quality monitoring conducted for the Teichert Vernalis facility(same a eg a processing activities as 1
<br /> at the Granite Plant),including pre-project and project monitoring,sh no e idence of groundwater -;
<br /> degradation. This'is igreem with several other surface excavatio o ations.in Yolo County,
<br /> where aggregate wa ter is re ycled and returned to the wet pit, and many years of monitoring have .
<br /> consistently do cu
<br /> qnfed no imp ct to groundwater quality to date(LSCS,2006,2008a,2008b, 2009).
<br /> These observations kky be ex ained by-the proportionally small amount of water lost to evaporation;
<br /> other losses (i.e.,pond tion and product moisture transported away)do not contribute to the
<br /> concentration of dissolved minerals in the recycled water.
<br /> Another mechanisms known to have the potential to cause groundw ter degradation i e' ' (1)",t'
<br /> dpward
<br /> migration of very dee 'ne oundwater from old marine deposits, elow the Tul e Fm�into the fresh
<br /> g rY p P
<br /> water aquifer system a d (2) teral movement of poorer quality groundwater fro the Sacramento-San
<br /> Joaquin River Delta int Sa Joaquin county due to excessive pumping. These processes are known as
<br /> saline intrusion and are monitored in th_e oy drafted areas of the county east of the San Joaquin River
<br /> (NSJCGBA, 2004; CDM,2001). �6st ted above,hh stb cal and recent groundwater levels in the
<br /> Y
<br /> vicinit of the Granite Vernalis Plant do not show signs of excessive pumping or overdraft conditions in,✓
<br /> that area. j
<br /> In summary,the potential for dry-pitit m�aggr/awashing operations to induce groundwater
<br /> quality changes in the underlying aquifer system are remote.
<br /> .3:G ndwater Monitoring P
<br /> Imp o groupwater resources,beyond the operational drawdown of water levels due to the pumping
<br /> of production wells, are remote and not expected as a result of Granite's mining operations at the
<br /> n quality data(dating
<br /> Vernalis Plant. This is supported b an extensive record of groundwater level and q y ( g
<br /> F PP Y
<br /> to 1994)compiled by Teichert Aggregates for its adjacent Vernalis plant,which produces aggregate at 4
<br /> MTY as compared to 2 MTY at the Granite Plant.
<br /> The groundwater.monitoring plan for the Granite Plant is proposed to build upon the existing data
<br /> record and consists of the following elements:
<br /> 1.
<br /> mi annual groundwater level measurements (to the nearest 100th of a foot) in five shallow
<br /> wells Hall Rustari Thomin Koster,4516E-5A1 ;o e com osite well (Petz), and ep
<br /> { a g, ) �---
<br /> we -ffs(South Tracy#3, Granite#4,'Brown's#1,Brown's New).- Water levels shall be .
<br /> measured in winter and late summer such as to capture conditions of seasonally high and low
<br /> 5 water levels.
<br /> Semi-annual groundwater quality retrieval from one shallow well(Hall)and three deep wells
<br /> (South Tracy 43, Granite 43,and Brown's New). Groundwater quality laboratoryanalyses
<br /> w1� shall consist of major cations and anions(Na,K,Mg, Ca,Cl,SO4,NO3,alkalinity series [total
<br /> alkalinity,HCO3,CO3, and OH]),pH,EC,TDS,B,and selected metals(Cu, Fe,'Mn,andZn)
<br /> 1 3. f or to sample retrieval,wells shall be purged. During the purging process,temperatur pH
<br /> and electrical conductivity shall be monitored and recorded. Sample retrieval shall occur a er
<br /> t these'parameters have stabilized(less than 10% fluctuation between two subsequent
<br /> measurements). Samples shall be transported to and analyzed by an ELAP-certified
<br /> (Environmental Laboratory Accreditation Program)laboratory within holding time such as to
<br /> ensure representative analytical results.
<br /> © LUHOORFF 5 SCALMANhNI
<br /> C O N S U L T I N G E N G I N E E R S
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