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Stormwater filtration practice (grass filters/swales) outflow concentrations and pollutant removals

Stormwater filtration practice (grass filters/swales) outflow concentrations and pollutant removals.

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Source TSS outflow concentration (mg/L) at a given Percentile TP outflow concentration (mg/L) at a given Percentile
25th 50th 75th 25th 50th 75th
ASCE/EPA 18 26 53 0.19 0.29 0.46
CWP 8 14 35 0.11 0.19 0.26
Source TSS Percent Removal at a given Percentile1 TP Percent Removal at a given Percentile1
25th 50th 75th 25th 50th 75th
ASCE/EPA 8 54 70 -121 -35 15
CWP 70 81 86 19 34 54

1MnDOT values for mean TSS removal=68% and mean TP removal=41%