Monthly Water Sampling Results for Silver Creek @ 172nd St. Download in CSV format

Sample Date by pH

Chloride mg/L Celsius C Fahrenheit F Transparency cm DO mg/L P mg/L N mg/L E. Coli MPN/100mL Ammonia mg/L Total Suspended Solids mg/L Chloride (Lab) mg/L Sulfate mg/L
06/27/17 00:00 11.3 3076 55.2 19.8 19.6
05/30/17 00:00 0.39 10.6 40.8 15.0 16.9
04/25/17 00:00 0.32 11.9 85 35.6 25.7 18.9
10/27/15 14:30 Eric Palas
09/29/15 15:45 Eric Palas 8.2 <29 17.5 63.5 13 5 0.67 0.5 959 39.6 17.9 8.6
08/25/15 13:45 Eric Palas 8.6 <29 16.6 61.9 40 6 0.33 2.7 75 18.8 21.2 21.1
07/28/15 12:40 Eric Palas 8.6 <29 22.9 73.2 28 7 0.23 6.2 146 17 19.3 19.7
06/30/15 14:45 Eric Palas 8.2 <29 17.0 62.6 60+ 9 0.73 12.0 3076 150 25.9 17.2
11/05/14 15:40 Eric Palas 8.2 <29 6.3 43.3 55 10 0.15 5.7 74
10/01/14 15:20 Brad Crawford 8.22 <29 12.3 54.1 18 8 0.48 <0.1 20
09/03/14 14:20 Eric Palas 8.1 <29 18.9 66.0 33 6 0.92 5.2 3100
08/06/14 14:50 Eric Palas 8.6 <29 20.2 68.4 35 8 0.2 11.0 31
07/09/14 13:00 Eric Palas 8.2 41 19.6 67.3 28 9 0.52 15.0 24000+
06/04/14 13:35 Eric Palas 8.2 <30 20.4 68.7 38 6 0.34 9.7 1600
05/07/14 13:30 Eric Palas 8.5 <30 12.0 53.6 55 9 0.24 12.0 1600
04/02/14 15:50 Eric Palas 8.7 <29 3.5 38.3 20 10 0.57 5.7 6500
11/06/13 14:30 Eric Palas 8.2 <30 6.1 43.0 40 9 0.47 5.9 41 0.13
10/16/13 14:00 Eric Palas 8.2 <30 10.5 50.9 35 5 0.29 <0.1 200 <0.05
09/04/13 14:15 Eric Palas 8.6 <30 17.0 62.6 35 10 0.23 5.5 190 <0.05
08/07/13 13:45 Eric Palas 8.3 30 21.4 70.5 20 7 0.31 9.9 16000 0.07
07/10/13 16:10 Brad Crawford 8.22 <30 19.2 66.6 17 9 0.35 15.0 2900 <0.05
06/05/13 16:10 Eric Palas 8.3 30 12.1 53.8 15 9 0.44 16.0 24000+ 0.14
05/01/13 13:00 Eric Palas 8.4 48 14.2 57.6 35 8 0.46 9.5 700 0.89
04/10/13 13:15 Eric Palas 8.5 <30 2.9 37.2 3 12 3.6 6.3 20000 0.75
11/07/12 18:00 8.66 <33 5.1 41.2 60+ 12 0.15 2.5 240 <0.05
10/03/12 15:35 7.65 <33 11.6 52.9 16 1 0.58 <0.1 41 <0.05
10/03/12 15:30 7.64 <33 14.1 57.4 15 2 0.63 <0.1 63 <0.05
09/05/12 19:35 7.68 <33 22.9 73.2 4 1 3.2 0.39 24000+ 1.1
08/01/12 18:00 <33 23.9 75.0 15 12 0.49 <0.1 290 <0.05
07/02/12 12:59 8.26 <33 24.4 76.0 10 4 0.54 5.7 6900 0.11
06/06/12 19:06 45 21.7 71.0 24 10 0.47 15.0 3700 0.15
05/02/12 17:50 7.68 45 16.1 61.0 9 6 1.2 7.8 24000 0.7
04/04/12 20:12 8.8 59 17.5 63.5 60+ 12 1.3 6.7 <10 0.19
11/02/11 17:50 8.3 <33 8.8 47.8 31 10 0.19 4.9 2400 <0.05
10/05/11 14:09 8.09 <33 11.4 52.5 41 5 0.24 5.5 230 <0.05
09/07/11 13:50 8.3 <33 13.8 56.8 12 7 0.62 4.8 5200 <0.05
09/07/11 13:45 8.3 33 13.8 56.8 12 6 0.59 4.9 2900 <0.05
08/03/11 12:30 7.87 <33 23.9 75.0 19 3 0.45 9.4 4800 0.97
07/06/11 17:20 8.35 <33 24.5 76.1 10 5.5 0.38 11.0 2100 0.06
06/01/11 13:45 8.2 14.8 58.6 15 0.47 14.0 2400 0.26
  • 10/27/2015: Dry stream segment
  • 08/25/2015: Limited flow,stream dry below sinkholes 2 miles upstream
  • 06/30/2015: 1 inch rain on 6/29/15 by landowners gage
  • 08/06/2014: Limited Stream Flow Near Bridge
  • 10/16/2013: Stagnant water, not flowing
  • 04/10/2013: Turbid
  • 10/03/2012: Sampled from bridge - stagnant water with oily surface
  • 10/03/2012: Sampled from bridge - stagnant water with oily surface
  • 07/02/2012: sampled from bridge
  • 06/06/2012: sampled from bridge
  • 11/02/2011: Tile line going in immediately upstream, DO was tested by breaking tip off under water (no beaker)

Yearly Averages for Silver Creek @ 172nd St. (with comparison to all sites in the watershed) Download in CSV format

pH

Chloride mg/L Celsius C Fahrenheit F Transparency cm DO mg/L P mg/L N mg/L E. Coli MPN/100mL Ammonia mg/L Total Suspended Solids mg/L Chloride (Lab) mg/L Sulfate mg/L
All Years 8.3 (8.3) <33 (<33) 15.6 (15.6) 60.1 (60.1) 29 (53) 7.6 (8.6) 0.62 (0.19) 7.5 (6.5) 963 (368) 0.27 (0.09) 51 (19) 20.69 (22.01) 17.43 (22.15)
2017 Mean 0.36 (0.16) 11.3 (8.8) 511 (183) 44 (16) 20.17 (21.33) 18.47 (15.88)
2015 Mean 8.4 (8.3) <33 (<33) 18.5 (17.3) 65.3 (63.1) 38 (53) 6.8 (7.2) 0.49 (0.23) 5.4 (6.1) 424 (442) 56 (20) 21.08 (22.17) 16.65 (23.58)
2014 Mean 8.3 (8.2) <33 (<33) 14.2 (14.6) 57.5 (58.3) 35 (57) 8.3 (8.4) 0.43 (0.18) 8.0 (7.3) 715 (196)
2013 Mean 8.3 (8.2) <33 (<33) 12.9 (13.6) 55.3 (56.5) 25 (46) 8.6 (8.8) 0.77 (0.27) 8.5 (7.6) 1524 (960) 0.26 (0.13)
2012 Mean 8.1 (8.3) 35 (<33) 17.9 (17.4) 64.2 (63.3) 28 (51) 7.3 (8.8) 0.99 (0.17) 4.8 (4.8) 893 (374) 0.3 (0.07) (16)
2011 Mean 8.2 (8.3) <33 (<33) 16.2 (15.9) 61.1 (60.7) 21 (58) 5.9 (9.0) 0.39 (0.1) 8.3 (6.4) 1839 (237) 0.24 (0.06)

How to Read the Table

GREEN: Better than average water quality compared to other sites in the watershed

BLACK: Average water quality compared to other sites in the watershed or N/A

RED: Worse than average water quality compared to other sites in the watershed

GRAY: The average value from all sites in the watershed. Useful for comparison.

*All averages are arithmetic means, except for E. Coli and/or Fecal Coliform, which are calculated as geometric means. For purposes of calculating a mean, values that exceed the measurement limit (e.g., <0.05, 60+, <33) are assumed to be 20% greater or less than their limit (e.g., 0.04, 72, 26.4).

Water Quality Standards

For 32.4% of the data records, Nitrate+Nitrite exceeded 10 mg/L. 10 mg/L represents the U.S. Public Health Service recommended limit of 10 mg/L NO3-N (nitrate-nitrogen) in drinking water.

For 66.7% of the data records, E. coli bacteria exceeded 235 CFU/100 ml. 235 CFU/100 ml represents Iowa's single sample maximum water quality standard for primary contact recreational use (Class A1), secondary contact recreational use (Class A2), and children's recreational use (A3).

One-time Rainfall Event Samples for Silver Creek @ 172nd St. (Not part of above statistics)

Sample Date by pH

Chloride mg/L Celsius C Fahrenheit F Transparency cm DO mg/L P mg/L N mg/L E. Coli MPN/100mL Ammonia mg/L Total Suspended Solids mg/L Chloride (Lab) mg/L Sulfate mg/L
03/11/13 20:43 Eric Palas/Pat Schaefers <33 2.3 36.1 14 0.81 1.2 1200 0.98

Site Information

NameSilver Creek @ 172nd St.
CodeSIL-10
CountyClayton
Latitude42.9731
Longitude-91.4417
UTM_X627072.0
UTM_Y4759004.0
NotesAdded June 2011
HUC_87060004
Sampled byNortheast Iowa Resource Conservation and Development

Sampling Location

Photos from SIL-10

Nearby Sampling Locations

Downstream →