| Report Year: 2009 |
| Lake Meyer, Winneshiek County |
| Summary Data Table |
| Parameter | 7/29/2009 | 6/24/2009 | 2009 | 2007 | 2006 | 2005 | 2004 | 2003 | 2002 | 2001 | 2000 |
| Lake Depth (m) | 7.5 | 7.5 | 7.5 | - | - | 7.4 | 7.7 | 7.7 | 7.9 | 7.3 | 8.1 |
| Thermocline Depth (m) | 1.7 | 1.7 | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A |
| Secchi Disk Depth (m) | 0.8 | 1.1 | 0.9 | - | - | 0.6 | 1.0 | 0.7 | 1.7 | 2.2 | 0.7 |
| Temperature(oC) | 22.9 | 25.0 | 24.0 | - | - | 26.5 | 23.2 | 22.8 | 23.9 | 22.2 | 22.9 |
| Dissolved Oxygen (mg/L) | 12.2 | 15.4 | 13.8 | - | - | 13.2 | 10.8 | 9.1 | 11.2 | 12.1 | 11.2 |
| Dissolved Oxygen Saturation (%) | 142 | 186 | 164.1 | - | - | 165.0 | 126.9 | 103.7 | 136.9 | 140.2 | 130.6 |
| Specific Conductivity (μS/cm) | 440.0 | 430.0 | 435.0 | - | - | 413.8 | 385.9 | 417.8 | 486.8 | 378.5 | 431.2 |
| Turbidity (NTU) | 15.8 | 10.1 | 13.0 | - | - | 23.5 | 14.3 | 28.5 | 19.2 | 22.1 | 22.9 |
| Chlorophyll a (μg/L) | 38.0 | 40.0 | 39.0 | - | - | 213.9 | 39.1 | 27.9 | 13.4 | 30.7 | 19.2 |
| Total Phosphorus as P (μg/L) | 78 | 37 | 57 | - | - | 72 | 130 | 108 | 65 | 68 | 61 |
| SRP as P (μg/L) | - | - | - | - | - | 1 | 43 | 32 | 1 | - | - |
| Total Nitrogen as N (mg/L) | 1.70 | 2.43 | 2.07 | - | - | 1.58 | 2.94 | 4.00 | 1.25 | 2.29 | 2.63 |
| (Phenate)Ammonia Nitrogen (NH3 + NH4+) as N (μg/L) | 16 | 16 | 16 | - | - | 98 | 135 | - | - | - | - |
| (Phenate)Ammonia Nitrogen (NH3) as N (un-ionized)(μg/L) | 1.0 | 4.0 | 2.5 | - | - | 11.7 | 12.8 | - | - | - | - |
| Nitrate + Nitrite (NO3 + NO2) as N (mg/L) | 0.28 | 1.28 | 0.78 | - | - | 0.32 | 2.33 | 2.72 | 0.47 | 1.18 | 1.09 |
| TN:TP ratio | 22 | 154 | 88 | - | - | 25 | 25 | 31 | 26 | 69 | 60 |
| pH | 9.0 | 9.0 | 9.0 | - | - | 8.9 | 8.5 | 8.7 | 8.6 | 8.7 | 7.1 |
| Alkalinity as CaCO3 (mg/L) | 154 | 155 | 155 | - | - | 151 | 146 | 107 | 159 | 138 | 183 |
| Silica as Si (mg/L) | - | - | - | - | - | 4.51 | 4.07 | 4.15 | 2.89 | - | - |
| Dissolved Organic Carbon (mg/L) | 4.91 | 4.50 | 4.71 | - | - | 6.85 | 4.42 | 8.84 | 8.82 | - | - |
| Inorganic Suspended Solids (mg/L) | 1 | 2 | 2 | - | - | 3 | 6 | 4 | 7 | 1 | 4 |
| Volatile Suspended Solids (mg/L) | 13 | 7 | 10 | - | - | 14 | 6 | 11 | 7 | 4 | 2 |
| Total Suspended Solids (mg/L) | 14 | 9 | 11 | - | - | 16 | 12 | 15 | 10 | 5 | 5 |
| Carlson Trophic State Index (Secchi)* | 64 | 59 | 61 | - | - | 68 | 61 | 65 | 52 | 49 | 65 |
| Carlson Trophic State Index (Chl a)* | 66 | 67 | 67 | - | - | 83 | 67 | 63 | 56 | 64 | 60 |
| Carlson Trophic State Index (TP)* | 67 | 56 | 62 | - | - | 66 | 74 | 72 | 64 | 65 | 63 |
| *Index values generally range between 0 and 100, with increasing values indicating more eutrophic conditions. |