Changes

Due to concerns about clogging, many types of facility may be constructed with limited or no filter fabric within:

Due to concerns about clogging, many types of facility may be constructed with limited or no filter fabric within:

*The use of filter fabric is referred to as a practice in 'older bioretention designs' In the upstate forever LID guide<ref>Upstate Forever. 2005. “Bioretention - LID Fact Sheet.” Greenville, South Carolina. https://www.upstateforever.org/files/files/CAW_LIDFact_Bioretention.pdf.</ref>. They go on to suggest that a [[choker course]] by used instead to separate the [[filter media]] and [[reservoir aggregate]].  Filter fabric may be used in side walls and should be placed directly over and within 2 feet of the [[perforated pipe]] drains when used in an [[underdrain]].  

*The use of filter fabric is referred to as a practice in ''"older bioretention designs"'' In the upstate forever LID guide<ref>Upstate Forever. 2005. “Bioretention - LID Fact Sheet.” Greenville, South Carolina. https://www.upstateforever.org/files/files/CAW_LIDFact_Bioretention.pdf.</ref>. They go on to suggest that a [[choker course]] by used instead to separate the [[filter media]] and [[reservoir aggregate]].  Filter fabric may be used in side walls and should be placed directly over and within 2 feet of the [[perforated pipe]] drains when used in an [[underdrain]]. Again, in Australia geotextile is only recommended around the sides of the practice :''"Geotextile fabrics are not recommended for use between layers in bioretention systems due to the risk of clogging."'', and :''"Conventional bioretention systems have... ...a permeable geotextile liner around their sides (no liner along the base)"'' <ref>Water by Design. 2014. Bioretention Technical Design Guidelines (Version 1.1). http://hlw.org.au/u/lib/mob/20150715140823_de4e60ebc5526e263/wbd_2014_bioretentiontdg_mq_online.pdf.</ref>. This practice is also seen in Massachusetts bioretention design documentation<ref>Massachusetts Department of Environmental Protection. . “Bioretention Areas.” 1999. http://prj.geosyntec.com/npsmanual/bioretentionareas.aspx.</ref><ref>Massachusetts Department of Environmental Protection. 2014. “Bioretention Areas & Rain Gardens.” 2014. http://prj.geosyntec.com/npsmanual/bioretentionareasandraingardens.aspx.</ref>

 

*In Finland the use of a choker course has been advocated for in place of filter fabric as replacing a clogged fabric layer would disturb established [[planting]]<ref>Tahvonen, O. 2018. Adapting Bioretention Construction Details to Local Practices in Finland. Sustainability 10(276). doi: doi:10.3390/su10020276.</ref>.  

*In Finland the use of a choker course has been advocated for in place of filter fabric as replacing a clogged fabric layer would disturb established [[planting]]<ref>Tahvonen, O. 2018. Adapting Bioretention Construction Details to Local Practices in Finland. Sustainability 10(276). doi: doi:10.3390/su10020276.</ref>.  

*Another recently revised document in Oklahoma suggests that geotextiles have a place in the base of the reservoir, but a choker course is best employed between layers inside the practice<ref>McLemore, A.J., J.R. Vogel, and S. Taghvaeian. 2017. “Bioretention Cell Design Guidance for Oklahoma.” http://pods.dasnr.okstate.edu/docushare/dsweb/Get/Document-10743/BAE-1536web.pdf.</ref>

*However, a recently revised document in Oklahoma suggests that geotextiles have a place in the base of the reservoir, but a choker course is best employed between layers inside the practice<ref>McLemore, A.J., J.R. Vogel, and S. Taghvaeian. 2017. “Bioretention Cell Design Guidance for Oklahoma.” http://pods.dasnr.okstate.edu/docushare/dsweb/Get/Document-10743/BAE-1536web.pdf.</ref>

:''"Conventional bioretention systems have... ...a permeable geotextile liner around their sides (no liner along the base)"'' <ref>Water by Design. 2014. Bioretention Technical Design Guidelines (Version 1.1). http://hlw.org.au/u/lib/mob/20150715140823_de4e60ebc5526e263/wbd_2014_bioretentiontdg_mq_online.pdf.</ref>. This practice is also seen in Massachusetts bioretention design documentation<ref>Massachusetts Department of Environmental Protection. . “Bioretention Areas.” 1999. http://prj.geosyntec.com/npsmanual/bioretentionareas.aspx.</ref><ref>Massachusetts Department of Environmental Protection. 2014. “Bioretention Areas & Rain Gardens.” 2014. http://prj.geosyntec.com/npsmanual/bioretentionareasandraingardens.aspx.</ref>