Concentrations of contaminants found in stormwater. Source: International Stormwater Database7. Because the data below are from a single source, values may differ from those contained on this page. We recommend if you are using emcs to quantify pollutant loading, you use this data instead of data from this table. Note that the table does not include information for chloride, a common pollutant in stormwater. Chloride concentrations vary seasonally and would be misrepresented in a single table. For more information on chloride concentrations in stormwater, see here.
Link to this table.

Land use TSS 1 NO2 + NO3 1 TN 1 TP 1 Cu 2 Zn 2 Ni 2 Cd 2 Cr 2 CN 2,5 Oil and grease 2 VOCs 2,5 Pesticides 2,4,5 FC 3,5 EC 3,5 FS 3,5
Commercial
Number of sites 56 50 13 56 60 62 40 51 38 2 44 4 1 4 -- 3
Number of observations 857 786 77 948 785 867 291 543 294 6 394 160 6 19 -- 7
% of samples above detection 98.7 98.9 97.4 94.5 85 99.2 51.5 38.1 52.0 0 65.5 65.5 0 73.7 -- 100
Minimum <0.5 <0.1 <1.5 <0.01 <0.2 <0.3 <1 <0.03 <0.7 n/a <0.5 <0.05 n/a <200 -- 310
Maximum 2385 8.2 18.1 4.27 569.1 3050.5 110 80 100 n/a 359 n/a 28000 -- 24000
Median 52 0.6 1.75 0.2 17 110 8 BDL6 4 BDL 5 0.7 n/a 450 -- 3100
Industrial
Number of sites 58 51 13 57 65 67 43 60 42 2 48 3 -- 6 -- 4
Number of observations 619 536 85 638 569 627 300 525 312 9 370 144 -- 32 -- 12
% samples above detection 99.5 97.0 95.3 95.1 85.1 98.9 58.0 48.6 72.4 0 59.7 10.4 -- 90.6 -- 91.7
Minimum <1 <0.02 <1.5 <0.02 <0.2 <0.5 <2 <0.03 <0.7 n/a <0.5 <0.05 -- <1 -- <1
Maximum 2490 8.4 15.2 7.9 1360 8100 120 334 150 n/a 408 -- 3600000 -- 48000
Median 75 0.68 1.7 0.23 19 155 10 BDL 10 BDL 5 BDL -- 3950 -- 24000
Residential
Number of sites 146 127 20 148 147 151 77 114 72 -- 95 7 1 10 3 4
Number of observations 2257 1772 131 2380 1743 2013 418 1123 408 -- 694 210 6 94 19 23
% of sample above detection 99.9 99.0 98.5 98.2 86.5 97.0 42.2 40.4 48.8 -- 56.8 20.1 0 85.9 100 95.7
Minimum <0.5 <0.03 <1.5 <0.01 <0.2 <0.5 <0.5 <0.03 <0.7 -- <0.5 <0.05 n/a <1 10 <1
Maximum 4168 66.4 18.3 19.90 590 14700 100 70 70 -- 419 3.42 n/a 5230000 35000 200000
Median 58 0.60 2.24 0.26 11 69.9 5 BDL 3 -- 4 BDL BDL 9400 1000 23500
Open space
Number of sites 15 13 4 15 12 12 9 8 7 3 9 1 -- 2 1 --
Number of observations 105 109 13 111 44 49 38 41 36 13 26 5 -- 6 5 --
% of samples above detection 97.1 92.7 92.3 93.7 64.4 65.3 23.1 39.0 36.1 15.4 34.6 60.0 -- 100 100 --
Minimum <1 <0.1 <0.5 <0.01 <0.8 <5 <2 <0.04 <0.7 <0.01 <1 <0.2 -- 1900 100 --
Maximum 4168 3.4 3.3 0.76 210 390 100 8 120 0.08 11 0.84 -- 63000 4700 --
Median 58 0.5 1.1 0.129 6 25 BDL BDL BDL BDL BDL 0.77 -- 2150 1100 --
Rooftop Water quality from rooftops varies with the type of roof. For more information see the section on Water quality considerations for stormwater and rainwater harvest and use/reuse

TSS=total suspended solids, NO2=nitrite, NO3=nitrate, TN=total nitrogen, Cl=chloride, Cu=copper, Zn=zinc, Ni=nickel, Cd=cadmium, Cr=chromium, CN=cyanide, VOC=volatile organic compound, FC=fecal coliform, EC=E. coli, FS=fecal streptococci
1 Concentrations are in milligrams per liter
2 Concentrations are in micrograms per liter
3 Concentrations are in Number per 100 milliliters
4Data is for trans-1,3-Dichloropropene and bromomethane
5 Data was selected from states with a similar climate to MN. The appropriate states were determined using Figure 1.3 from the Stormwater BMP Design Supplement for Cold Climates document.
6BDL = below detection level
7The following censoring techniques were used for this data:

  • If detection rates were 90% or greater, a value of "0" was substituted for non-detects.
  • If detection rates were greater than 50% but 90% or less, a value of 1/2 the detection limit was substituted for non-detects.
  • If detection rates were 50% or less, the median was assumed to be below the method detection level.

This page was last modified on 13 January 2020, at 14:35.

Minnesota Pollution Control Agency | 651-296-6300, 800-657-3864 | Assistance | Web site policy