Iowa DNR
AQuIA

Water Quality Monitoring

Surface Waters - Groundwater
Physical - Chemical

Ambient Lake Monitoring

The Ambient Lake Monitoring program samples lakes in Iowa over the summer recreational season. Each lake is sampled three times between May and September: once in early summer, once in mid-summer, and once in late summer/early fall. Data from this project are used to assess the health of our lakes and target individual lakes for restoration and watershed improvement activities. Monitoring is currently completed through a partnership with the Iowa State University Limnology Laboratory.

Current Ambient Lake Sites

SiteID Site County

Lake Water Quality Summary 2008 to 2018

Summary statistics last calculated 12/11/2018 10:16:41 AM
Analyte Units # Results Min 10th Percentile 25th Percentile Median 75th Percentile 90th Percentile Max Max Sample Date % Non-detection
Ammonia mg/l 3,108 <0 <0 <0.001 0.004 0.01 0.016 0.433 7/17/2017 27.12
Ammonia-nitrogen mg/l 4,276 Not calculated when non-detections exceed 50% 50.35
Calcium carbonate mg/l 2,796 9 83.905 99.1425 128.875 165 197 485 8/6/2018 0.00
Chlorophyll a ug/l 3,943 <0.4 <4 8.365 23 46 80 416.96 8/18/2014 10.63
Depth, Secchi disk depth m 4,222 0.1 0.3 0.5 0.7 1.3 2.4 10 7/21/2015 0.00
Dissolved oxygen (DO) mg/l 4,210 0.8 5.6 7.2 8.8 10.6 12.7 30.2 5/23/2011 0.00
Dissolved oxygen saturation % 3,560 9.1 65.89 84.0975 102.75 123.6 150.805 313.8 6/21/2010 0.00
Escherichia coli MPN 236 <1 <1 <1 2 5.2 13.5 410.6 9/20/2017 30.93
Fixed suspended solids mg/l 4,275 <0.6 <1.4 <3 4.3 8 15 378 5/31/2011 32.77
Inorganic nitrogen (nitrate and nitrite) mg/l 4,276 Not calculated when non-detections exceed 50% 62.91
Kjeldahl nitrogen mg/l 3,884 <0.16 0.5 0.8346625 1.21 1.77 2.42 12.92 8/8/2011 6.82
Microcystin ug/l 757 Not calculated when non-detections exceed 50% 69.88
Orthophosphate mg/l 4,268 Not calculated when non-detections exceed 50% 69.80
pH None 4,219 6.7 7.8 8.1 8.4 8.7 8.95 10.4 8/6/2009 0.00
Phosphate-phosphorus mg/l 4,248 <0.01 0.0284 0.0452 0.07715 0.13025 0.2147 1.0519 7/25/2017 1.91
Phycocyanin ug/l 798 <0 <3.3 7 18 51 116.6 1016 7/31/2018 24.31
Specific conductance uS/cm 4,225 0.202 210 260 350 450 550 1091 8/27/2018 0.00
Temperature, water deg C 4,225 10.34 18.4 21.4 23.9 26 27.4 31.7 8/3/2010 0.00
Total dissolved solids mg/l 3,449 45 140 170 222 300 360 709 8/27/2018 0.00
Total suspended solids mg/l 4,275 <0.8 4 6.6 11.8 19.5 32 452 5/31/2011 7.93
Turbidity NTU 4,064 <0 2.079 5.2 11.2 21.6 39 462.5 6/3/2013 0.94
Volatile Suspended Solids mg/l 3,067 <0 <3 <5.6 8 11.4 18 130 7/22/2013 28.14
Project Codes in this Program

Project Type Description

Program Details

Results (2008 to 2018) 76,381
Sites

Additional Summary Calculations

Parameter Value
TSI (ChlA) 65
TSI (Secchi) 59
TSI (TP) 71