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b) There may be an isolated zone where water is collected and trapped by a low permeability layer which is limited in extent to the immediate area around well P-1. An open well extending through such an isolated zone might indicate a somewhat higher phreatic surface, as the actual water level in the well could be significantly influenced by the isolated zone of high pressure. Even though a well through such a zone would be influenced, it could not be expected to accurately measure the higher pore pressures that may exist. Wells at different depths would possibly show varying water levels based on the permeability of the zones they pass through and the water available to each of those zones. c) When an embankment is constructed over a zone of ' saturated compressible soil, the pore pressures in that zone increase as the embankment weight is added. The amount of pressure increase is dependent on the t compressibility of the soil, the weight of the overlying embankment and the permeability of the material. In some cases where the compressibility is great and the permeability is low, the pressures can become high enough ' to raise the water level higher than the top of the embankment. These pressures are relieved over time as the excess pore water drains out. If the permeability of ' the soil is low, the drainage process could involve a considerable amount of time. If, in this example a portion of the embankment was constructed over a pond or ' an area with a high water table, elevated pore pressures could develop during placement of the pile material. However, there are several considerations that make it unlikely that high pore pressures have developed in this ' way. First, even though the original alluvial overburden in the vicinity of wells P-1 and P-2 is exceptionally thick (30 to 40-feet) there is no available evidence to ' suggest that a pond or area of high water table existed in the vicinity of P-1. Second, it seems unlikely that either the original foundation alluvium or the pile ' refuse material would be impervious enough to maintain elevated pore pressures for a period of years. It would also be unusual to have higher water levels in shallower wells caused by construction pore pressures. ' Other areas farther north (along the bench) appear to be influenced, intermittently and/or to a lesser degree, by the same ' or similar conditions noted above. The reduced influence is evidenced by piezometric measurements in PZ P-2 and PZ P-3 which have shown dry conditions to a depth of +/- 30-feet, in the past. The primary source of water feeding the zones measured by the northern wells is obviously precipitation moisture collected and temporarily stored by the pile. However, measurements of water levels in wells which extend into the original alluvial foundation ' 15 1