Changes

{{float right|[[File:perf pipe.gif|border|600 px|Exfiltration trench under high flow and exfiltration conditions]]}}

{{float right|[[File:Perf pipe resize small.gif|417 × 194 px|Exfiltration trench under high flow and exfiltration conditions]]}}

Exfiltration trenches are similar to [[infiltration trenches]] but differ primarily in the the manner in which stormwater is delivered to the trench.<br>

Exfiltration trenches are similar to [[infiltration trenches]] but differ primarily in the the manner in which stormwater is delivered to the trench.<br>

Runoff enters infiltration trenches directly by infiltration from the surface. In exfiltration systems, surface runoff is collected by drainage [[inlets]] and delivered to the trench via subsurface perforated [[pipes]].

Runoff enters infiltration trenches directly by infiltration from the surface. In exfiltration systems, surface runoff is collected by drainage [[inlets]] and delivered to the trench via subsurface perforated [[pipes]].

*All new road/storm sewer constructions where no constraints to infiltration exist,  

*All new road/storm sewer constructions where no constraints to infiltration exist,  

*Tight urban spaces where no landscaped practices can be squeezed in, and there is a low risk tolerance for flooding.}}

*Tight urban spaces where no landscaped practices can be squeezed in, and there is a low risk tolerance for flooding.}}

'''The fundamental components of an exfiltration system are:'''

'''The fundamental components of an exfiltration system are:'''

*[[pretreatment| pre-treatment devices]] to retain coarse sediment, trash, debris and floatables,

*[[pretreatment| pre-treatment devices]] to retain coarse sediment, trash, debris and floatables,