Changes

This article is about underground systems which distribute concentrated flow along a level, linear facility to promote infiltration to native soils. <br>

This article is about underground systems which distribute concentrated flow along a level, linear facility to promote infiltration to native soils. <br>

For a similar structure, which differs in being designed to receive excess flow and convey it, while promoting infiltration to native soils, see [[exfiltration trenches]].

See [[exfiltration trenches]] for guidance on infiltration trench systems integrated with conventional storm sewers and manholes that provide both infiltration and conveyance functions.  

[[File:Kortright trench.PNG|thumb|The infiltration trench at Kortright is topped with [[filter fabric]] and decorative [[stone]], both of which provide some [[pretreatment]] and can easily be removed and replaced as an occasional maintenance task. For more details click [https://sustainabletechnologies.ca/app/uploads/2016/08/BioVSTrench_TechBrief__July2015.pdf here] ]]   

 

[[File:Kortright trench.PNG|thumb|This infiltration trench features an inlet composed of [[geotextile| filter fabric]] and decorative [[stone| river stone]], which provides some [[pretreatment]] and can easily be removed and replaced as part of routine sediment removal maintenance. For more details click [https://sustainabletechnologies.ca/app/uploads/2016/08/BioVSTrench_TechBrief__July2015.pdf here] ]]   

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==Overview==

==Overview==

*Balancing the requirements to infiltrate excess stormwater whilst conveying excess}}

*Balancing the requirements to infiltrate excess stormwater whilst conveying excess}}

'''The fundamental components of an infiltration trench are:'''  

'''The fundamental components of an infiltration trench are:'''  

*Storage reservoir to temporarily store water, filled with [[Reservoir_gravel|coarse aggregate]] and possibly void-forming structures to minimize depth and conserve aggregate, and organic material derived from untreated wood (aids in dissolved nitrogen removal);

*Water storage reservoir, filled with [[Reservoir_gravel|coarse aggregate]], possibly void-forming structures to minimize depth and conserve aggregate, and organic material derived from untreated wood (aids in dissolved nitrogen removal);

*[[Pipes|Perforated pipes]] to deliver water to the trench and convey excess flow to a downstream storm sewer or other BMP; and

*[[Pipes|Perforated pipes]] to deliver water to the trench and convey excess flow to a downstream storm sewer or other BMP; and

*[[Geotextile]] to maintain separation between the storage reservoir and surrounding native soil.

*[[Geotextile]] to maintain separation between the storage reservoir and surrounding native soil.

*Virginia up to 10' (3 m) deep. <ref>Viriginia Department of Transport. (2010). VDOT BMP Design Manual of Practice. Retrieved March 15, 2018, from http://www.virginiadot.org/business/resources/LocDes/BMP_Design-Manual/Chapter_8_Infiltration_Trench.pdf</ref>

*Virginia up to 10' (3 m) deep. <ref>Viriginia Department of Transport. (2010). VDOT BMP Design Manual of Practice. Retrieved March 15, 2018, from http://www.virginiadot.org/business/resources/LocDes/BMP_Design-Manual/Chapter_8_Infiltration_Trench.pdf</ref>

*Minnesota up to 12' (3.6 m) deep. <ref>Design criteria for Infiltration trench. (2016, September 21). Minnesota Stormwater Manual, . Retrieved 13:25, April 4, 2018 from https://stormwater.pca.state.mn.us/index.php?title=Design_criteria_for_Infiltration_trench&oldid=28702.</ref>

*Minnesota up to 12' (3.6 m) deep. <ref>Design criteria for Infiltration trench. (2016, September 21). Minnesota Stormwater Manual, . Retrieved 13:25, April 4, 2018 from https://stormwater.pca.state.mn.us/index.php?title=Design_criteria_for_Infiltration_trench&oldid=28702.</ref>

*"...not normally be deeper than 3 to 4 m in order to maximise the length of the flow path to the water table through the unsaturated zone." <ref>Design of soakaways (2015) www.tiipublications.ie/library/DN-DNG-03072-01.pdf</ref>

*"...not normally deeper than 3 to 4 m in order to maximise the length of the flow path to the water table through the unsaturated zone." <ref>Design of soakaways (2015) www.tiipublications.ie/library/DN-DNG-03072-01.pdf</ref>

*There is a cost implication with digging deeper practices, trench boxes may be required to retain the side walls during construction.

*There is a cost implication with designing deeper practices.  If >2.0 m deep, trench shorings are required to support the side walls during construction.

==Materials==

==Materials==