| Report Year: 2009 |
| Lower Gar Lake, Dickinson County |
| Summary Data Table |
| Parameter | 7/7/2009 | 6/3/2009 | 2009 | 2007 | 2006 | 2005 | 2004 | 2003 | 2002 | 2001 | 2000 |
| Lake Depth (m) | 1.5 | 1.6 | 1.6 | 1.7 | 1.5 | 1.6 | 1.2 | 1.6 | 1.3 | 1.6 | 1.2 |
| Thermocline Depth (m) | Nil | Nil | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A |
| Secchi Disk Depth (m) | 0.6 | 1.4 | 1.0 | 0.8 | 0.6 | 0.7 | 0.4 | 1.2 | 0.4 | 1.0 | 0.4 |
| Temperature(oC) | 26.1 | 19.5 | 22.8 | 23.0 | 24.8 | 20.9 | 22.4 | 21.2 | 19.8 | 23.8 | 24.3 |
| Dissolved Oxygen (mg/L) | 11.0 | 11.8 | 11.4 | 8.6 | 7.8 | 9.5 | 9.0 | 7.8 | 9.0 | 9.3 | 9.0 |
| Dissolved Oxygen Saturation (%) | 136 | 128 | 132.0 | 100.3 | 94.3 | 105.3 | 103.7 | 86.6 | 99.5 | 112.2 | 107.6 |
| Specific Conductivity (μS/cm) | 500.0 | 490.0 | 495.0 | 496.3 | 517.3 | 525.8 | 561.4 | 535.4 | 554.2 | 515.0 | 651.2 |
| Turbidity (NTU) | 26.3 | 5.2 | 15.8 | 28.2 | 22.1 | 46.5 | 449.4 | 19.7 | 44.5 | 38.0 | 37.3 |
| Chlorophyll a (μg/L) | 31.0 | 4.0 | 17.5 | 34.7 | 15.8 | 13.4 | 42.1 | 21.5 | 37.9 | 21.5 | 46.7 |
| Total Phosphorus as P (μg/L) | 104 | 29 | 67 | 100 | 87 | 69 | 106 | 74 | 189 | 91 | 236 |
| SRP as P (μg/L) | 11 | 1 | 6 | 20 | 30 | 36 | 24 | 3 | 10 | - | - |
| Total Nitrogen as N (mg/L) | 1.73 | 0.77 | 1.25 | 1.44 | 1.62 | 1.11 | 1.75 | 1.41 | 1.70 | 1.21 | 1.57 |
| (Phenate)Ammonia Nitrogen (NH3 + NH4+) as N (μg/L) | 22 | 16 | 16 | 23 | 154 | 58 | 96 | - | - | - | - |
| (Phenate)Ammonia Nitrogen (NH3) as N (un-ionized)(μg/L) | 5.2 | 1.7 | 3.4 | 2.5 | 15.9 | 5.7 | 13.8 | - | - | - | - |
| Nitrate + Nitrite (NO3 + NO2) as N (mg/L) | 0.12 | 0.12 | 0.12 | 0.28 | 0.57 | 0.35 | 0.54 | 0.35 | 0.63 | 0.40 | 0.31 |
| TN:TP ratio | 17 | 27 | 22 | 16 | 19 | 19 | 17 | 21 | 9 | 14 | 7 |
| pH | 8.7 | 8.8 | 8.8 | 8.4 | 8.3 | 8.4 | 8.6 | 8.5 | 8.4 | 8.0 | 8.3 |
| Alkalinity as CaCO3 (mg/L) | 214 | 223 | 219 | 210 | 211 | 204 | 197 | 164 | 226 | 145 | 201 |
| Silica as Si (mg/L) | - | - | - | - | - | 6.62 | 12.73 | 5.39 | 7.12 | - | - |
| Dissolved Organic Carbon (mg/L) | 6.96 | 6.98 | 6.97 | 6.76 | 6.56 | 5.01 | 7.25 | 10.49 | 11.11 | - | - |
| Inorganic Suspended Solids (mg/L) | 12 | 3 | 8 | 21 | 13 | 10 | 21 | 8 | 75 | 17 | 16 |
| Volatile Suspended Solids (mg/L) | 12 | 2 | 7 | 13 | 6 | 6 | 12 | 7 | 23 | 8 | 11 |
| Total Suspended Solids (mg/L) | 24 | 5 | 15 | 34 | 19 | 16 | 32 | 15 | 98 | 18 | 27 |
| Carlson Trophic State Index (Secchi)* | 67 | 55 | 60 | 64 | 67 | 65 | 73 | 57 | 75 | 60 | 74 |
| Carlson Trophic State Index (Chl a)* | 64 | 44 | 59 | 65 | 58 | 56 | 67 | 61 | 66 | 61 | 68 |
| Carlson Trophic State Index (TP)* | 71 | 53 | 65 | 71 | 69 | 65 | 71 | 66 | 80 | 69 | 83 |
| *Index values generally range between 0 and 100, with increasing values indicating more eutrophic conditions. |