Agenda - Council - 10/26/2021 - Laserfiche WebLink

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3.3 Groundwater Groundwater was encountered in soil boring SB-2 at about 12 below the ground surface corresponding to about elevations 855 1/2. Groundwater was not observed in the remaining borings. The observed water levels are summarized in Table 2. Table 2. Summary of Groundwater Levels Boring Number Ground Surface Elevation (ft) Approximate Depth to Groundwater (ft)* Approximate Groundwater Elevation (ft)* SB-01 874.3 NE - SB-02 867.5 12 855 1/2 SB-03 871.8 NE - SB-04 881.4 NE - SB-05 879.6 NE - SB-06 881.5 NE - * = Depths and Elevations were rounded to the nearest 1/2 foot. NE = Not Encountered We made water level measurements in the borings at the times and under the conditions stated on the boring logs. The period of observation was relatively short and fluctuations in the groundwater level may occur due to rainfall, flooding, irrigation, spring thaw, drainage, and other seasonal and annual factors not evident at the time the observations were made. The intensity and duration of these events or factors can significantly impact groundwater levels. In addition, "extreme" weather events or other events, such as flooding, spring thaw, etc., could result in groundwater levels higher than estimated or anticipated. Groundwater monitoring wells or piezometers in conjunction with deeper borings would be required to more accurately determine water levels. 3.4 Laboratory Tests Six (6) laboratory moisture content tests and 6 percent passing the #200 sieve (P-200) tests were performed on selected samples of the aggregate base or possible aggregate base materials. Laboratory P-200 contents of the aggregate base materials ranged from about 6 1/2 percent to 11 percent. It should be noted that the aggregate base materials appeared to contain very little "gravel" and for that reason the material was described as possible aggregate base. Table 3 below provides a summary of the laboratory testing. Laboratory moisture contents and P-200 contents are also shown on the boring logs adjacent to the samples tested. Table 2. Summary of Laboratory Analysis r Boring 1e Same p Depth (feet) Moisture Content (%)* P-200 (�/)* SB-01 AU-1 Possible Agg Base 31/2 11 SB-02 AU-8 Possible Agg Base 3 71/2 SB-03 AU-15 Possible Agg Base 4 7 SB-04 AU-22 Possible Agg Base 7 61/2 SB-05 AU-29 Possible Agg Base 3 7 SB-06 AU-37 Possible Agg Base 3 7 *Moisture contents and P-200 contents were rounded to the nearest 1/2 percent. 4