Laserfiche WebLink
especially in clay-type soils, requiring a prolonged soaking <br /> period. In preparation of percolation measurements, twelve (12) <br /> inches of clear water are maintained above the gravel level for a <br /> period of 24 hours. For most soil types it is necessary to refill <br /> the hole during this time with a surplus reservoir of water or by <br /> an automatic siphon. <br /> [3] PERCOLATION RATE MEASUREMENT <br /> With the exception of sandy soils, percolation rate measurements <br /> are performed the day following the saturation and swelling of the <br /> soil. <br /> [A] If water remains in the test hole following the period <br /> of saturation and swelling, the water level is adjusted to <br /> approximately six (6) inches above the gravel level. The drop <br /> in water level is then measured from a fixed reference point <br /> for a thirty (30) minute period. This drop is used to <br /> calculate the percolation rate. <br /> [B] If no water remains in the test hole following the period <br /> of saturation and swelling, clear water is added until the <br /> depth of water is approximately six (6) inches above the <br /> gravel level. The drop in water level is then measured from <br /> a fixed reference point for thirty (30) minute intervals for <br /> a period of four (4) hours, refilling six (6) inches above the <br /> gravel level as necessary. The drop occurring during the <br /> final thirty (30) minute interval will be used to calculate <br /> the percolation rate. <br /> [c] In sandy soils a ten (10) minute interval between <br /> measurements is used over a two (2) hour period. The drop in <br /> water level during the final ten (10) minute interval is used <br /> to calculate the percolation rate. <br /> @Z� Quality Control Inspection <br />