respective MLS wells. In Table 2-2, there are a number of no-value (nv) values where tracers

did not arrive at the sampling location. The values with asterisks indicate estimated pre-flood SN

using a method described later. Most of these were observed at the lowest depth, indicating

probable lower hydraulic conductivity. One of the disadvantages of PITTs is the inability or

difficulty of tracers to arrive at a MLS or RW. Most tracers never reached MLS-5 and MLS-7 in

the PITTs. Without at least the conservative tracer reaching the sampling points, the fluid flow

velocity or PCE saturations. However, both RW-5 and RW-7 received tracers and recorded

initial average PCE saturations greater than 0.5 %, the highest of the RW data set.

Table 2-2. PCE saturations from the pre-flood PITT. No-value (nv) indicates not
 enough tracers arrived at the well to resolve the PCE saturations. Column 2 is the
 RW and mean MLS results, the other columns are the specific MLS depth PITT
 results. Asterisked values were determined in section 2.11.
 Well Pre PCE SN 8.08 m 8.69 m 9.07 m 9.45 m 9.91 m

 RW-2 0.322
 RW-3 0.553
 RW-4 0.236
 RW-5 0.569
 RW-6 0.238
 RW-7 0.584
 Mean MLS
 MLS-1 0.610 1.342 1.071 0.313 0.217 0.110*
 MLS-2 0.373 0.773 0.199 0.675 0.101 0.115
 MLS-3 0.801 1.060 0.257 0.461 1.552 0.675*
 MLS-4 1.367 0.107 1.146 0.925 2.029 2.628*
 MLS-5 nv nv nv nv nv nv
 MLS-6 1.015 0.135 0.510 0.698 1.686 2.044
 MLS-7 nv 0.066 nv 0.181* 0.510* nv

 In the upper zone of MLS-1 and MLS-3, the highest upper source zone saturations were

detected. This is closest to the location of the drycleaner floor drain in Figure 2-1. In the mid-

depths, MLS-2, MLS-4, and MLS-6 returned the higher average PCE saturations. This indicated

PCE moving from the upper zone around MLS-1 and MLS-3 and then collecting in the mid-

depths in the wells encircling this region. At the bottom of the sampling zone, the highest PCE

saturations were observed in MLS-4 and MLS-6, up to 2.6% indicating pooling in this region.