Stormwater pond outflow concentrations and pollutant removals.
Link to this table

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 11 13 25 0.08 0.13 0.20
CWP 11 17 34 0.07 0.11 0.17
Source
TSS Percent Removal at a given Percentile1
TP Percent Removal at a given Percentile1
25th 50th 75th 25th 50th 75th
ASCE/EPA 60 88 94 29 48 69
CWP 60 80 86 39 51 76

1MnDOT values for mean TSS removal=65% and mean TP removal=52%