| Note also that the fragments all appear to have a film of fine particles adhering; this material would be improved by being washed prior to use.]] | | Note also that the fragments all appear to have a film of fine particles adhering; this material would be improved by being washed prior to use.]] |
| This article gives recommendations for aggregate to be used to store water for infiltration. This is usually called 'Clear stone' at aggregate yards. To see an analysis of Ontario Standard Specifications for granular materials, see [[OPSS aggregates]]. For advice on decorative surface aggregates see [[Stone]] | | This article gives recommendations for aggregate to be used to store water for infiltration. This is usually called 'Clear stone' at aggregate yards. |
| Gravel used for [[underdrains]] in [[bioretention]], [[infiltration trenches]] and [[infiltration chambers|chambers]], and [[exfiltration trenches]] should be 20 OR 50 mm, uniformly-graded, clean (maximum wash loss of 0.5%), crushed angular stone that has a void ratio of 0.4<ref>Porosity of Structural Backfill, Tech Sheet #1, Stormtech, Nov 2012, http://www.stormtech.com/download_files/pdf/techsheet1.pdf accessed 16 October 2017 </ref>. | | Gravel used for [[underdrains]] in [[bioretention]], [[infiltration trenches]] and [[infiltration chambers|chambers]], and [[exfiltration trenches]] should be 20 OR 50 mm, uniformly-graded, clean (maximum wash loss of 0.5%), crushed angular stone that has a void ratio of 0.4<ref>Porosity of Structural Backfill, Tech Sheet #1, Stormtech, Nov 2012, http://www.stormtech.com/download_files/pdf/techsheet1.pdf accessed 16 October 2017 </ref>. |