Changes

Jump to navigation Jump to search
Line 1: Line 1:  
This method of determining [[design infiltration rate]] is only suitable for coarse-textured native soils with d<sub>10</sub> between 0.1 - 2.5 mm (i.e. soils to which the Hazen formula is applicable)<ref>San Francisco Public Utilities Commission. (2017). Determination of Design Infiltration Rates for the Sizing of Infiltration‐based Green Infrastructure Facilities. Retrieved from http://sfwater.org/modules/showdocument.aspx?documentid=9681</ref>.  
 
This method of determining [[design infiltration rate]] is only suitable for coarse-textured native soils with d<sub>10</sub> between 0.1 - 2.5 mm (i.e. soils to which the Hazen formula is applicable)<ref>San Francisco Public Utilities Commission. (2017). Determination of Design Infiltration Rates for the Sizing of Infiltration‐based Green Infrastructure Facilities. Retrieved from http://sfwater.org/modules/showdocument.aspx?documentid=9681</ref>.  
   −
'''This method must not be applied within areas of fill or in regions where hydraulic conductivity is controlled by vertical fractures in the soil matrix.'''  
+
'''This method shall not be applied within areas of fill or in regions where hydraulic conductivity is controlled by vertical fractures in the soil matrix.'''  
    
==Procedure==
 
==Procedure==
 
# Collect soil samples for each defined soil layer below the bottom of the proposed infiltration facility. Layers must be evaluated to the following depths, depending upon facility type:
 
# Collect soil samples for each defined soil layer below the bottom of the proposed infiltration facility. Layers must be evaluated to the following depths, depending upon facility type:
 
#* For [[bioretention]] facilities, analyze each defined layer below the proposed facility bottom to a depth of at least 3 times the maximum ponding depth, but not less than 1 m.  
 
#* For [[bioretention]] facilities, analyze each defined layer below the proposed facility bottom to a depth of at least 3 times the maximum ponding depth, but not less than 1 m.  
#* For [[permeable paving]], analyze each defined layer below the proposed facility bottom to a depth of at least 3 times the maximum depth of water within the base course, but not less than 1 m.  
+
#* For [[permeable pavements]], analyze each defined layer below the proposed facility bottom to a depth of at least 3 times the maximum depth of water within the base course, but not less than 1 m.  
 
#* For other types of infiltration facilities serving drainage areas up to 4 Ha, analyze each defined layer below the proposed facility bottom to a depth of at least 2.5 times the water storage reservoir depth, but not less than 3 m.  
 
#* For other types of infiltration facilities serving drainage areas up to 4 Ha, analyze each defined layer below the proposed facility bottom to a depth of at least 2.5 times the water storage reservoir depth, but not less than 3 m.  
 
# Submit the soil samples to a certified soil testing laboratory for grain-size, or particle-size distribution analysis according to [https://www.astm.org/Standards/D422.htm ASTM D422] Standard Test Method for Particle-size Analysis of Soils.
 
# Submit the soil samples to a certified soil testing laboratory for grain-size, or particle-size distribution analysis according to [https://www.astm.org/Standards/D422.htm ASTM D422] Standard Test Method for Particle-size Analysis of Soils.
339

edits

Navigation menu