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CJ secondary suction lysimeter, this is evidence that the lysimeters installed below the Landfill 2 (LF -2) liner of module 1 are not in saturated soil. A rush laboratory turnaround was requested for the September 6 samples. The VOC laboratory testing was completed on September 7, 2018. As shown on the attached lab report, several VOCs were again detected. However, the number and concentration of VOCs were lower from the September 2018 verification sample as compared to the initial August 2018 sample, as shown below: Since the fluid extracted from LZ -4 contains landfill gas (LFG) volatile compounds and does not have characteristics of leachate, and since it is in such small quantity, the most likely source of this unsaturated vadose zone water is the condensation of LFG vapors from the adjacent unlined portion of Landfill 1 (LF -1). It should be noted that LF -2 was ruled out as a source of LFG vapors. It is unlikely that LFG from LF -2 is the source, as the temperature of the water extracted from LZ -4 is approximately 23 degrees C, which is less than that of leachate in LF -2. It is an accepted condition that LFG is migrating from the unlined landfill LF -1, which is promoted by the over -liner (piggyback liner) installed over waste on the east side of LF -1 (See Figure 1). It is believed that LFG vapors from unlined LF -1 that are trapped under the LF -2 over -liner are migrating under the LF -2 liner system toward LZ -4. Due to the presence of moisture in the soil at LZ -4, it is believed that these vapors are cooling in the soil beneath LF -2. Moisture entrained in the LFG may form condensate in the unsaturated soil under the LF -2 liner. When vacuum is applied to LZ -4, this condensate/moisture would be drawn into the body of the suction lysimeter, and thus be expelled to the surface in the form of a liquid when pressure is applied to the lysimeter body. The LFG vapors migrating under the LF -2 liner must not be that extensive, as only limited amounts of condensate can be withdrawn at the LZ -4 location. In addition, fluid or condensate was not produced at the other suction lysimeter locations beneath LF -2 (LZ -2 and LZ -3). Although the amount of condensate appears to be minimal, in order to curtail its reoccurrence and to control the LFG migration, the County must proceed with its current LFG corrective 2 LZ -4 Sample Date & Result Parameter Units 8/2/2018 9/6/2018 Benzene ug/L 0.35 J 0.27 J 1,4 -Dichlorobenzene ug/L 0.23 J 0.15 J cis-1,2-Dichloroethene ug/L 0.13 J <0.085 Ethylbenzene ug/L 0.26 J 0.12 J Tetrachloroethene ug/L 0.31 J 0.25 J Toluene ug/L 0.16 J <0.093 Trichloroethene ug/L 0.12 J <0.085 Trichlorofluoromethane ug/L 0.22 J <0.13 Total Xylenes ug/L 0.98 J 0.60 J Acetone ug/L 200 130 All other VOCs ND ug/L ND ND Since the fluid extracted from LZ -4 contains landfill gas (LFG) volatile compounds and does not have characteristics of leachate, and since it is in such small quantity, the most likely source of this unsaturated vadose zone water is the condensation of LFG vapors from the adjacent unlined portion of Landfill 1 (LF -1). It should be noted that LF -2 was ruled out as a source of LFG vapors. It is unlikely that LFG from LF -2 is the source, as the temperature of the water extracted from LZ -4 is approximately 23 degrees C, which is less than that of leachate in LF -2. It is an accepted condition that LFG is migrating from the unlined landfill LF -1, which is promoted by the over -liner (piggyback liner) installed over waste on the east side of LF -1 (See Figure 1). It is believed that LFG vapors from unlined LF -1 that are trapped under the LF -2 over -liner are migrating under the LF -2 liner system toward LZ -4. Due to the presence of moisture in the soil at LZ -4, it is believed that these vapors are cooling in the soil beneath LF -2. Moisture entrained in the LFG may form condensate in the unsaturated soil under the LF -2 liner. When vacuum is applied to LZ -4, this condensate/moisture would be drawn into the body of the suction lysimeter, and thus be expelled to the surface in the form of a liquid when pressure is applied to the lysimeter body. The LFG vapors migrating under the LF -2 liner must not be that extensive, as only limited amounts of condensate can be withdrawn at the LZ -4 location. In addition, fluid or condensate was not produced at the other suction lysimeter locations beneath LF -2 (LZ -2 and LZ -3). Although the amount of condensate appears to be minimal, in order to curtail its reoccurrence and to control the LFG migration, the County must proceed with its current LFG corrective 2