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→Salt & LID
==Salt & LID==
==Salt & LID==
[[File:Bypass bioretention.png|thumb|400px|Example of a bypass in use to limit runoff from entering into a [[bioretention]] cell BMP. (Photo Source: TRCA, 2021)]]
[[File:Bypass bioretention.png|thumb|350px|Example of a bypass in use to limit runoff from entering into a [[bioretention]] cell BMP. (Photo Source: TRCA, 2021)]]
[[File:LID Salt reduction.png|thumb|500px|The above graph shows research conducted by the STEP group comparing the chloride level discharges between asphalt, and two commonly used LID practices ([[Permeable pavement]] and [[Bioretention]]. The results show that asphalt releases salt in concentrated bursts during winter whereas the LIDs release it more gradually over the entire year, thus the level of chloride entering into receiving to streams from PP and Bioretention are much lower!]]
Since salt has deleterious effects on many plant species, there is often concern that [[plants]] in LID receiving salt laden road runoff will not fare well over time. Several design features are meant to address these risks, including:
Since salt has deleterious effects on many plant species, there is often concern that [[plants]] in LID receiving salt laden road runoff will not fare well over time. Several design features are meant to address these risks, including:
*Perforated distribution pipes that are offset from root balls to reduce exposure during early tree establishment ([[Stormwater Tree Trenches]])
*Perforated distribution pipes that are offset from root balls to reduce exposure during early tree establishment ([[Stormwater Tree Trenches]])
In drinking water protection areas, bypasses may be used to limit exposure to road salts during winter months where aquifers are vulnerable and ensures that any heavily-laden stormwater will "bypass" the practice and flow to the downstream street inlet to the Municipality's storm sewer system.
In drinking water protection areas, bypasses may be used to limit exposure to road salts during winter months where aquifers are vulnerable and ensures that any heavily-laden stormwater will "bypass" the practice and flow to the downstream street inlet to the Municipality's storm sewer system.
LID typically delays the release of salt to receiving waters through temporary storage of elevated chloride levels in soils and then slowly releases it over time. This can help to reduce peak concentrations in discharges and push discharges into the spring when streams have greater dilution capacity. Runoff infiltration in LID practices also helps reduce salt loading to streams that can harm riparian, aquatic and semi-aquatic fauna and flora species.
==Salt Alternatives==
==Salt Alternatives==