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A percolation test (colloquially called a perc test) is a test to determine the water absorption rate of soil (that is, its capacity for percolation) in preparation for the building of a septic drain field (leach field) or infiltration basin. [1] The results of a percolation test are required to design a septic system properly.
Groundwater recharge is an important process for sustainable groundwater management, since the volume-rate abstracted from an aquifer in the long term should be less than or equal to the volume-rate that is recharged. Recharge can help move excess salts that accumulate in the root zone to deeper soil layers, or into the groundwater system.
For example, in geology, percolation refers to filtration of water through soil and permeable rocks. The water flows to recharge the groundwater in the water table and aquifers . In places where infiltration basins or septic drain fields are planned to dispose of substantial amounts of water, a percolation test is needed beforehand to determine ...
Owing to irregular distribution of salt in the soil or to irregularity of the soil structure (figure 2), the leaching efficiency (E L) can be different from unity. Soils with a low leaching efficiency are difficult to reclaim. In the Tagus delta, Portugal, the leaching efficiency of the dense clay soil was found as low as 0.10 to 0.15. [4]
Soils that have smaller pore sizes, such as clay, have lower infiltration capacity and slower infiltration rates than soils that have large pore sizes, such as sands. One exception to this rule is when the clay is present in dry conditions. In this case, the soil can develop large cracks which lead to higher infiltration capacity. [3]
Infiltration basins must be carefully designed to infiltrate the soil on a given site at a rate that will not cause flooding. They may be less effective in areas with: High groundwater levels, close to the infiltrating surface; Compacted soils; High levels of sediment in stormwater; High clay soil content. [6]
All were exposed to a virus that causes the common cold. “It turned out that both groups got equal rates of infection,” he says. Myth #3: Vitamin C can prevent a cold.
Coarse soils – sand and gravel – can transmit wastewater away from the drain field before pathogens are destroyed. Silt and clay effectively filter out pathogens but limit wastewater flow rates. [3] Percolation tests measure the rate at which clean water disperses through a disposal trench into the soil.