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c:"�� for homogeneous soils. These rates not consider the effects ofsite �, variability and long-teml clogging due to siltation and bi�mass buildup in � the infiltration facility. Table 3.7 -- Recommended Infiltration Fdates based on USDA Soit Textural Classiflcation. Estim�ted Long- *Short-Teran Term (Design) Infiltration Correction Infilfration Rate Yiate {in.lhr) I'Actor, CF (in✓hr) Clean sandy gravels and 20 2 10�� gravelly sands (i.e., 90% of the total soil sample is retained in the #] 0 sieve) Sand 8 4 2**« Loamy Sand 2 4 0.5 Sandy Loam 1 4 0.25 Loam 0.5 4 0.13 �hrom ��4h'F/A5('t?, 199h. �`��TNot recommendcd for treatmeni t''� Refer to SSC-4 and SSC-6 fbr treafiien[ acceptability criteria Based on experience with Jong-term full-scale infiltration pond performance, Ecology's Teciinical Advisory Committee (TAC) recommends that the short-term infiltration rates be reduced as showr� in Table 3.7, dividing by a correction factor of 2 to 4, depending on the soil textural ciassification. The correction factors provided in Table 3.7 represent an average degree of long-#erm facility maintenance, TSS reduction through pretreatment, and site variability in the subsurface conditions. These conditions might inciude deposits of ancient landslide debris, buried stream channeis, lateral grain size variability, and other factors that affect homogeneity). These conection factors could be reduced, subject to the approval ofthe locai jurisdiction, under the following conditions: • For sites with iittle soil variability, • Where there �viil be a high degree of long-term facility maintenance, � �T+Ihere specifc, reliable pretreatment is employed to reduce TSS en#ering the infiltration facility Yn �o ca�e shall a correc#ion faetor less than 2.0 be used. 3-76 Volume 11! — Hydrologic Analysis and Flow Contral BMPs FBbnlary 2005 �L,�-�� .�-�'