Laserfiche WebLink
A91 <br /> (4) Percolation Rate measurement : <br /> a. In sandy soils adjust the water depth to eight (8) <br /> inches above the soil at the bottom of the test | | <br /> hole. From a fixed reference point , the drop in <br /> water level shall be measured in inches to the <br /> nearest one-eigth ( 1/8) inch at ten ( 10) minute <br /> intervals. If eight (8) inches of water seeps <br /> away in less than ten ( 10) minutes, a shorter time <br /> interval may be used . But in no case shall the <br /> depth of water exceed eight (8) inches. The test <br /> shall continue until three (3) consecutive <br /> measurements vary by no more than ten ( 10) <br /> percent. <br /> b. In other than sandy soils, adjust the water depth <br /> to eight (8) inches over the soil at the bottom of <br /> the test hole. From a fixed reference point, the <br /> drop in water level shall be measured in inches to <br /> the nearest one-eight ( 1/8) inch at thirty (30) <br /> minute intervals, refilling after each measurement <br /> to maintain an eight (8) inch starting head . The <br /> test shall -c-ontinue until three (3) consecutive <br /> measurements vary by no more than ten ( 10) <br /> percent. The rate may also be measured by <br /> observing the time it takes the water level to <br /> drop one ( 1 ) inch from an eight (8) inch reference „ <br /> point, provided a constant water depth of at least <br /> eight (8) inches has been maintained for at least <br /> four (4) hours immediately prior to the <br /> measurement. <br /> ( 5) Calculation of Percolation Rates: <br /> a. Divide the time interval by the drop in water <br /> level to obtain the percolation rate in minutes <br /> per inch. <br /> b. Percolation rates shall be determined for each <br /> test hole and recorded on worksheets showing all <br /> measurements and calculations' <br /> (6) Percolation tests shall not be run where frost exists <br /> at and below the test hole bottom. <br /> 404 . Construction and Materials. ' <br /> 404.01 . Building Sewers. The design , construction , and location <br /> of and the materials permitted for use in building sewers shall be as <br /> regulated by the Minnesota State Building Code as it may be amended ' <br /> � ! <br /> 12 <br /> 2 <br />