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Line 1: − <div class="col-md-8">{{TOClimit|2}}+ − <p>Filter media should be obtained premixed from a vendor and meet all municipal, provincial and federal environmental standards. Mixing of sand, topsoil and compost should be done in a manner that preserves topsoil peds. The mixture should be free of stones, stumps, roots, or other debris larger than 50 mm diameter. Samples of the filter media should be dried, ground and tested to ensure they meet the following specifications:</p>+ + − <ul>+ − <li>70 - 80 % coarse sand</li>+ − <li>10 - 15 % topsoil</li>+ − <li>10 - 15 % organic soil component</li>+ − </ul>+ + + Line 17:
Line 20: − ===Sand===+ − ===Topsoil===+ − ===Organic components===+ − + − <p>Compost is the most widely used organic component. It's use in bioretention facilities is well established and documented. Low-phosphorus composts should always be sought for use in low impact development facilities, including bioretention. These are typically created from feedstocks including yard, leaf, and wood waste, and must exclude manures, biosolids, and food scraps.<ref>Hurley S, Shrestha P, Cording A. Nutrient Leaching from Compost: Implications for Bioretention and Other Green Stormwater Infrastructure. J Sustain Water Built Environ. 2017;3(3):4017006. doi:10.1061/JSWBAY.0000821.</ref></p>+ − <strong>[[Compost|Compost Specifications]]</strong>+ + + + − <p>Even low-phosphorus composts are known to export phosphorus over many years. The use of compost is not recommended in watersheds for which phosphorus pollution is a concern. There are alternatives which have undergone field study, each of which has a number of benefits and potential concerns: Line 34:
Line 39: − + − + + − </p> − ===Additives===+ − <p>Typically these components would comprise 5- 10 % by volume of the filter media mixture. + +
no edit summary
{{TOClimit|2}}
[[File:Sandy Bioretention Soil Mix.jpg|thumb|Sandy filter media mix]]
It is recommended that the mixture comprises:
It is recommended that the mixture comprises:
*70 - 80 % coarse sand
*10 - 15 % topsoil
*10 - 15 % organic soil component
Filter media should be obtained premixed from a vendor and meet all municipal, provincial and federal environmental standards. Mixing of sand, topsoil and compost should be done in a manner that preserves topsoil peds. The mixture should be free of stones, stumps, roots, or other debris larger than 50 mm diameter. Samples of the filter media should be dried, ground and tested to ensure they meet the following specifications:
The final blended product should have the following properties:
The final blended product should have the following properties:
<table class = "table table-striped table-responsive">
<table class = "table table-striped table-responsive">
<caption><strong></strong></caption>
<caption><strong></strong></caption>
<tr><td>[[Hydraulic conductivity]]</td><td>> 25 mm/hr <br> <250 mm/hr</td><td>Falling head or constant head KSAT</td></tr>
<tr><td>[[Hydraulic conductivity]]</td><td>> 25 mm/hr <br> <250 mm/hr</td><td>Falling head or constant head KSAT</td></tr>
</table>
</table>
==Sand==
{{:Sand}}
{{:Sand}}
==Topsoil==
{{:Topsoil}}
{{:Topsoil}}
==Organic components==
<h5>Compost</h5>
<h3>Compost</h3>
Compost is the most widely used organic component. It's use in bioretention facilities is well established and documented. Low-phosphorus composts should always be sought for use in low impact development facilities, including bioretention. These are typically created from feedstocks including yard, leaf, and wood waste, and must exclude manures, biosolids, and food scraps.<ref>Hurley S, Shrestha P, Cording A. Nutrient Leaching from Compost: Implications for Bioretention and Other Green Stormwater Infrastructure. J Sustain Water Built Environ. 2017;3(3):4017006. doi:10.1061/JSWBAY.0000821.</ref>
'''[[Compost|Compost Specifications]]'''
Even low-phosphorus composts are known to export phosphorus over many years. The use of compost is not recommended in watersheds for which phosphorus pollution is a concern. There are alternatives which have undergone field study, each of which has a number of benefits and potential concerns:
<table class = "table table-striped table-responsive">
<table class = "table table-striped table-responsive">
<caption><strong>Organic soil components</strong></caption>
<caption><strong>Organic soil components</strong></caption>
</table>
</table>
<h5>Coconut coir</h5>
<h3>Coconut coir</h3>
http://www.modularwetlands.com/new/wp-content/uploads/2015/11/2-Bioretention-Synthesis-2015-DAhearn.pdf
http://www.modularwetlands.com/new/wp-content/uploads/2015/11/2-Bioretention-Synthesis-2015-DAhearn.pdf
<h5>Wood derivatives</h5>
<h3>Wood derivatives</h3>
https://www.unh.edu/unhsc/sites/default/files/media/unhsc_bsm_spec_2-28-17_0.pdf
https://www.unh.edu/unhsc/sites/default/files/media/unhsc_bsm_spec_2-28-17_0.pdf
https://www.unh.edu/unhsc/sites/unh.edu.unhsc/files/STONE%20THESIS%20FINAL.pdf
https://www.unh.edu/unhsc/sites/unh.edu.unhsc/files/STONE%20THESIS%20FINAL.pdf
https://jbioleng.biomedcentral.com/articles/10.1186/s13036-017-0057-4 (focus on denitrification)
https://jbioleng.biomedcentral.com/articles/10.1186/s13036-017-0057-4 (focus on denitrification)
==Additives==
Typically these components would comprise 5- 10 % by volume of the filter media mixture.
It is recommended that this fraction be taken from the topsoil or the organic portion otherwise; keeping the sand as minimum 65 % by volume. </p>
It is recommended that this fraction be taken from the topsoil or the organic portion otherwise; keeping the sand as minimum 65 % by volume. </p>
{{:Additives}}
{{:Additives}}