| Report Year: 2009 |
| Prairie Rose Lake, Shelby County |
| Summary Data Table |
| Parameter | 7/14/2009 | 6/10/2009 | 2009 | 2007 | 2006 | 2005 | 2004 | 2003 | 2002 | 2001 | 2000 |
| Lake Depth (m) | 5.9 | 6.0 | 6.0 | 6.5 | 6.4 | 6.5 | 6.8 | 6.7 | 6.2 | 6.7 | 6.1 |
| Thermocline Depth (m) | 3.9 | Nil | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A |
| Secchi Disk Depth (m) | 0.9 | 0.6 | 0.7 | 0.6 | 0.8 | 0.9 | 0.5 | 1.1 | 0.7 | 0.7 | 0.5 |
| Temperature(oC) | 25.1 | 20.0 | 22.5 | 25.3 | 25.8 | 23.9 | 21.3 | 24.2 | 24.7 | 23.3 | 25.3 |
| Dissolved Oxygen (mg/L) | 12.1 | 8.5 | 10.3 | 10.7 | 8.9 | 9.1 | 8.1 | 10.7 | 9.6 | 8.3 | 9.7 |
| Dissolved Oxygen Saturation (%) | 147 | 93 | 120.0 | 132.0 | 109.1 | 107.6 | 91.8 | 128.5 | 114.7 | 91.8 | 117.5 |
| Specific Conductivity (μS/cm) | 380.0 | 430.0 | 405.0 | 319.6 | 383.6 | 363.8 | 355.9 | 363.9 | 371.4 | 320.1 | 336.8 |
| Turbidity (NTU) | 9.4 | 19.9 | 14.7 | 35.0 | 22.1 | 23.0 | 57.7 | 18.3 | 17.7 | 26.8 | 31.8 |
| Chlorophyll a (μg/L) | 37.0 | 30.0 | 33.5 | 75.8 | 49.3 | 81.2 | 29.2 | 21.5 | 59.1 | 37.0 | 23.4 |
| Total Phosphorus as P (μg/L) | 59 | 62 | 60 | 86 | 61 | 115 | 137 | 64 | 70 | 117 | 133 |
| SRP as P (μg/L) | 1 | - | 1 | 1 | 1 | 3 | 48 | 2 | 2 | - | - |
| Total Nitrogen as N (mg/L) | 2.04 | 0.77 | 1.41 | 4.38 | 1.49 | 1.69 | 4.03 | 1.65 | 1.17 | 1.80 | 1.52 |
| (Phenate)Ammonia Nitrogen (NH3 + NH4+) as N (μg/L) | 118 | 443 | 281 | 51 | 21 | 268 | 242 | - | - | - | - |
| (Phenate)Ammonia Nitrogen (NH3) as N (un-ionized)(μg/L) | 26.2 | 40.0 | 33.1 | 5.6 | 5.4 | 23.1 | 48.7 | - | - | - | - |
| Nitrate + Nitrite (NO3 + NO2) as N (mg/L) | 1.00 | 0.74 | 0.87 | 3.84 | 0.37 | 0.37 | 2.77 | 0.46 | 0.18 | 1.01 | 0.23 |
| TN:TP ratio | 35 | 12 | 23 | 81 | 26 | 20 | 50 | 32 | 19 | 17 | 16 |
| pH | 8.7 | 8.4 | 8.5 | 9.0 | 8.7 | 8.4 | 8.6 | 8.3 | 8.5 | 8.2 | 8.2 |
| Alkalinity as CaCO3 (mg/L) | 168 | 190 | 179 | 122 | 149 | 145 | 126 | 101 | 141 | 139 | 140 |
| Silica as Si (mg/L) | - | - | - | - | - | 2.81 | 8.29 | 1.38 | 1.92 | - | - |
| Dissolved Organic Carbon (mg/L) | 3.29 | 4.31 | 3.80 | 3.66 | 6.13 | 3.80 | 4.33 | 9.38 | 8.31 | - | - |
| Inorganic Suspended Solids (mg/L) | 14 | 9 | 11 | 7 | 6 | 5 | 34 | 7 | 4 | 10 | 8 |
| Volatile Suspended Solids (mg/L) | 7 | 8 | 7 | 14 | 7 | 9 | 11 | 6 | 8 | 4 | 8 |
| Total Suspended Solids (mg/L) | 21 | 17 | 19 | 21 | 13 | 14 | 45 | 13 | 12 | 14 | 16 |
| Carlson Trophic State Index (Secchi)* | 62 | 67 | 65 | 68 | 63 | 62 | 69 | 58 | 65 | 66 | 70 |
| Carlson Trophic State Index (Chl a)* | 66 | 64 | 65 | 73 | 69 | 74 | 64 | 61 | 71 | 66 | 62 |
| Carlson Trophic State Index (TP)* | 63 | 64 | 63 | 68 | 63 | 73 | 75 | 64 | 65 | 73 | 75 |
| *Index values generally range between 0 and 100, with increasing values indicating more eutrophic conditions. |