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kn KLEINFELDER • Total coliform bacteria were reported in each of the monitoring well samples collected with concentrations ranging from 12 to more than 23 Most Probable Numbers per 100 milliliter (MPN/100ml). Fecal coliform bacteria were reported in the MW-6 sample with a concentration of 16.1 MPN/100mi. Coliform bacteria is typical. Iron was detected in groundwater samples collected from MW-3, MW-4, MW-7, and MW-9 with concentrations exceeding the Secondary Maximum Contaminant Level (SMCL) of 300 µg/l_ by 6 to 103 percent. SMCLs are aesthetic standards not typically related health risks. Other general water quality data showed that the Total Dissolved Solids (TDS) concentrations ranged from 260 mg/L to 710 mg/L across the site. The TDS concentrations exceeded the recommended level SMCL for TDS of 500 mg/L in three out of the eight wells (MW-2, MW-4, MW-9), but did not exceed the SMCL upper level of 1,000 mg/L. TDS concentrations are cumulative results of many of the individual constituents dissolved in the groundwater, which include anions and cations. The Specific Conductance concentrations were the highest in MW-2 (1,110 umhos/cm) and MW-4 (1 ,080 umhos/cm). TheEC measured in all of the groundwater samples ranged from 540 to 1 ,110 umohs/cm. The SMCL for EC is 900 umhos/cm, with a SMCL • upper level of 1,600 umhos/cm. One deep exploratory boring was advanced near the sites eastern boundary in order to assess the potential for non-potable supplies of groundwater to use for lake make-up water and common area landscape irrigation. The deep exploratory boring was drilled using a mud rotary drilling method and zone tested for water quality between January 30 and February 9, 2005. The deep boring was drilled to a total depth of approximately 400 feet bgs. The lithology encountered consisted of interbedded sand, silt and clay layers. Significant clay layers were shown to exist between the more permeable sand layers tested. Three zones were selected for water quality testing based on the results of the lithologic and geophysical logs (Resistivity, Spontaneous Potential, and Gamma ray). The depths of the zones tested were approximately 385-395 (Zone #1), 195-215 (Zone #2), and 163-183 (Zone #3) feet bgs. The results of the zone testing showed elevated concentrations of most analytes in the shallowest zone (Zone #3) versus the two deeper zones (Zone #1 and Zone #2), often greater than two times. The concentrations of nitrate as NO3 and sodium exceeded the MCL's in Zone #3. The concentration of manganese exceeded the MCL in Zone #1 , and the concentration of sodium exceeded the SNARL in all three zones. • 63138.H01/ST06R312/JDZ:Iv Page 2 of 20 April 7, 2006 ©2006 Kleinfelder, Inc.