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
11/01/17 00:00 Eric Palas 8.6 3.1 37.6 35 0.26 9.2 749 70 16.9 20.9
09/26/17 00:00 Eric Palas 8.1 19.9 67.8 11 1.6 2.7 24196 63.2 24.5 22.5
09/05/17 00:00 Eric Palas 8.5 16.8 62.2 18 0.23 8.6 66 42.8 17.9 20.5
07/25/17 00:00 Eric Palas 8.4 17.1 62.8 26 0.28 13.2 2613 48.5 22.4 20.0
06/27/17 00:00 Eric Palas 8.4 14.9 58.8 19 11.3 3076 55.2 19.8 19.6
05/30/17 00:00 Eric Palas 8.4 13.0 55.4 31 0.39 10.6 40.8 15.0 16.9
04/25/17 00:00 Eric Palas 8.2 11.3 52.3 22 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
  • 09/26/2017: 1.6" rain
  • 09/05/2017: Limited flow, stream dry below sinkholes 2 miles upstream
  • 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) 15.3 (15.6) 59.5 (60.0) 28 (52) 7.6 (8.6) 0.62 (0.2) 7.5 (6.6) 995 (372) 0.27 (0.09) 53 (33) 20.59 (25.04) 18.72 (22.66)
2017 Mean 8.4 (8.3) 13.7 (13.2) 56.7 (55.8) 23 (35) 0.51 (0.51) 9.6 (8.8) 967 (298) 51 (79) 20.31 (34.35) 19.9 (19.7)
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 31.7% 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 67.5% 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

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