| Report Year: 2009 |
| Lake Anita, Cass County |
| Summary Data Table |
| Parameter | 6/9/2009 | 7/13/2009 | 2009 | 2007 | 2006 | 2005 | 2004 | 2003 | 2002 | 2001 | 2000 |
| Lake Depth (m) | 9.5 | 9.6 | 9.6 | 8.8 | 7.3 | - | - | 8.9 | 8.6 | 8.0 | 8.5 |
| Thermocline Depth (m) | 4.2 | 3.8 | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A |
| Secchi Disk Depth (m) | 1.8 | 0.8 | 1.3 | 1.0 | 0.9 | - | - | 1.4 | 0.8 | 1.0 | 0.9 |
| Temperature(oC) | 20.8 | 24.6 | 22.7 | 25.2 | 24.9 | - | - | 23.3 | 25.2 | 23.3 | 25.3 |
| Dissolved Oxygen (mg/L) | 10.0 | 9.9 | 9.9 | 11.6 | 7.2 | - | - | 8.0 | 9.6 | 8.2 | 8.8 |
| Dissolved Oxygen Saturation (%) | 111 | 119 | 115.1 | 140.3 | 86.3 | - | - | 93.7 | 120.6 | 90.9 | 106.7 |
| Specific Conductivity (μS/cm) | 280.0 | 250.0 | 265.0 | 297.8 | 329.6 | - | - | 286.0 | 289.7 | 243.9 | 274.0 |
| Turbidity (NTU) | 10.2 | 11.0 | 10.6 | 16.2 | 11.8 | - | - | 17.1 | 20.0 | 25.8 | 14.2 |
| Chlorophyll a (μg/L) | 12.0 | 38.0 | 25.0 | 48.6 | 38.3 | - | - | 18.8 | 55.1 | 58.0 | 17.2 |
| Total Phosphorus as P (μg/L) | 30 | 65 | 47 | 67 | 57 | - | - | 67 | 60 | 48 | 107 |
| SRP as P (μg/L) | - | 1 | 1 | 1 | 1 | - | - | 2 | 2 | - | - |
| Total Nitrogen as N (mg/L) | 0.28 | 1.27 | 0.67 | 0.78 | 1.54 | - | - | 1.20 | 1.16 | 1.38 | 1.12 |
| (Phenate)Ammonia Nitrogen (NH3 + NH4+) as N (μg/L) | 149 | 19 | 84 | 16 | 16 | - | - | - | - | - | - |
| (Phenate)Ammonia Nitrogen (NH3) as N (un-ionized)(μg/L) | 17.5 | 1.5 | 9.5 | 1.5 | 1.3 | - | - | - | - | - | - |
| Nitrate + Nitrite (NO3 + NO2) as N (mg/L) | 0.12 | 0.12 | 0.12 | 0.12 | 0.40 | - | - | 0.12 | 0.12 | 0.14 | 0.33 |
| TN:TP ratio | 2 | 20 | 11 | 13 | 30 | - | - | 19 | 20 | 33 | 12 |
| pH | 8.5 | 8.2 | 8.3 | 8.7 | 8.5 | - | - | 8.4 | 8.3 | 8.1 | 7.8 |
| Alkalinity as CaCO3 (mg/L) | 120 | 104 | 112 | 120 | 116 | - | - | 83 | 106 | 107 | 120 |
| Silica as Si (mg/L) | - | - | - | - | - | - | - | 1.08 | 1.62 | - | - |
| Dissolved Organic Carbon (mg/L) | 6.24 | 5.16 | 5.70 | 6.81 | 7.36 | - | - | 9.67 | 9.47 | - | - |
| Inorganic Suspended Solids (mg/L) | 2 | 4 | 3 | 2 | 4 | - | - | 6 | 3 | 7 | 12 |
| Volatile Suspended Solids (mg/L) | 4 | 9 | 7 | 8 | 6 | - | - | 8 | 10 | 6 | 8 |
| Total Suspended Solids (mg/L) | 6 | 13 | 9 | 10 | 10 | - | - | 14 | 14 | 13 | 13 |
| Carlson Trophic State Index (Secchi)* | 52 | 63 | 56 | 61 | 61 | - | - | 55 | 63 | 60 | 62 |
| Carlson Trophic State Index (Chl a)* | 55 | 66 | 62 | 69 | 66 | - | - | 59 | 70 | 70 | 59 |
| Carlson Trophic State Index (TP)* | 53 | 64 | 60 | 65 | 62 | - | - | 65 | 63 | 60 | 71 |
| *Index values generally range between 0 and 100, with increasing values indicating more eutrophic conditions. |