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♦.. \ l <br /> the pore water infiltrated and percolated through this sand stratum, thus exhibiting an excellent = <br /> perc rate of 6.3 min/in. Since the 12,ft boring did not extend down into this sand stratum, this <br /> test boring recorded a final perc rate of 83 min/in. - - <br /> - HYDRAULIC CONDUCTIVITY TEST <br /> - As referenced on the Log of Boring,the subsurface soils consist predominately of finer-sized silt <br /> and clay particles. The hydraulic conductivity (K)of the.vadose zone (subsurface soils) <br /> _ u r <br /> _ determines the_potential for water infiltration4nto the embankments and floor of the holding = _ <br /> pond and consequently the downward flow characteristics of-water:!To quantify this parameter, - <br /> the Shallow-Well Pump-In Test Method (Soil Science.Society.of America) was employed.= The <br /> - ' <br /> test was conducted adjacent to the west of the holding`pond,20 ft northeast of the 45:ft deep_ -_ <br /> exploratory boring: The test boring_was drilled-downto 10 ft below grade,:A.constant level.of- <br /> water was supplied to the b to a Height of 9:ft: The rate at whicli:water flowed into the soil _- <br /> (Q) was determined to b 600'cc/hr�fter the four-hour,test. Although the soil characteristics are = _ <br /> relatively constant the entire ength of the test boring,.an average-hi draulic conductivity:is <br /> obtained by this method. The equation to determine the hydraulic conductivity in cm/hr is as, - <br /> follows: _ <br /> K= 3 1n r <br /> 11 h(h+2Tu) - _ <br /> Where: <br /> h= 9 ft (274..3 cm) <br /> r= 0.67:ft (20.4 cm) - <br /> N Q = 1,200 cc/hr <br /> 1- T,, = 9",ft(274.3 cm) Y <br />` Therefore, K= 0.0132'em/hr(3 '7 x:10-6 cm/s) - - - <br /> These test results show.the hydraulic conductivity of the'subsoil silt.stfata.possess a <br /> � comparatively slow permeability and_suggest it would theoretically-take a water molecule _ <br /> approximately.9,141 days or 25 ye_arsao=travel from near the soli surface_to the water table, X95 <br /> ft below grade. Summarization of the physical soil tests: <br /> -, - - - <br /> PERCOLATION/HYDRAU, i CONDUMVIT TEST- ,'RESULTS <br /> PERC TEST = PERC RATE IN MIN/INCH' <br /> Leachline depth-42 inches..initial:Test _._ - 0 min/in-Failed =— _ <br /> = Leachline depth-42 inches. Second-Test _ = - - 1,5-min/in `= <br /> Sump depth- 12 ft' >, 83 min/in - <br /> - .T Seepage pit-23 ft :.� = - 6:3'min/in. <br /> Hydraulic Conductivity Test,- 10 ft deep= _ 3 = �0.0132.c' Thr <br /> V 7 <br /> 5 <br /> a a;�h_ , <br /> v C�ey�[B hese _ - - <br />