| Report Year: 2009 |
| Nelson Park Lake, Crawford County |
| Summary Data Table |
| Parameter | 7/15/2009 | 6/10/2009 | 2009 | 2007 | 2006 | 2005 | 2004 | 2003 | 2002 | 2001 | 2000 |
| Lake Depth (m) | 6.2 | 6.6 | 6.4 | 6.0 | 5.9 | 6.4 | 6.5 | 6.4 | 5.9 | 6.5 | 6.4 |
| Thermocline Depth (m) | 3.7 | 4.4 | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A |
| Secchi Disk Depth (m) | 3.9 | 2.0 | 2.9 | 1.4 | 2.9 | 2.1 | 2.6 | 3.1 | 1.5 | 1.5 | 1.6 |
| Temperature(oC) | 25.3 | 20.2 | 22.7 | 25.2 | 25.7 | 24.3 | 20.0 | 23.7 | 26.4 | 22.8 | 25.5 |
| Dissolved Oxygen (mg/L) | 6.4 | 8.9 | 7.6 | 9.4 | 8.9 | 9.0 | 10.3 | 10.3 | 9.6 | 7.2 | 10.5 |
| Dissolved Oxygen Saturation (%) | 78 | 98 | 88.0 | 114.0 | 108.4 | 105.4 | 113.2 | 121.2 | 118.9 | 79.8 | 127.7 |
| Specific Conductivity (μS/cm) | 460.0 | 450.0 | 455.0 | 450.4 | 404.7 | 460.0 | 416.3 | 424.5 | 499.7 | 414.0 | 390.4 |
| Turbidity (NTU) | 1.7 | 3.1 | 2.4 | 7.0 | 12.9 | 5.7 | 1.6 | 4.9 | 14.0 | 8.2 | 8.2 |
| Chlorophyll a (μg/L) | 5.0 | 6.0 | 5.5 | 15.8 | 23.5 | 26.3 | 6.2 | 13.2 | 26.5 | 22.6 | 17.3 |
| Total Phosphorus as P (μg/L) | 38 | 38 | 38 | 33 | 31 | 40 | 34 | 44 | 45 | 54 | 75 |
| SRP as P (μg/L) | - | - | - | 1 | 1 | 2 | 1 | 2 | 1 | - | - |
| Total Nitrogen as N (mg/L) | 4.19 | 0.28 | 2.12 | 1.01 | 0.81 | 0.79 | 0.57 | 0.67 | 1.32 | 1.07 | 1.59 |
| (Phenate)Ammonia Nitrogen (NH3 + NH4+) as N (μg/L) | 320 | 109 | 215 | 83 | 20 | 30 | 16 | - | - | - | - |
| (Phenate)Ammonia Nitrogen (NH3) as N (un-ionized)(μg/L) | 33.2 | 10.0 | 21.6 | 9.5 | 5.9 | 3.6 | 0.9 | - | - | - | - |
| Nitrate + Nitrite (NO3 + NO2) as N (mg/L) | 0.13 | - | 0.13 | 0.57 | 0.12 | 0.14 | 0.17 | 0.12 | 0.60 | 0.33 | 0.23 |
| TN:TP ratio | 111 | 1 | 56 | 31 | 27 | 20 | 17 | 15 | 33 | 23 | 21 |
| pH | 8.3 | 8.4 | 8.3 | 8.4 | 8.8 | 8.4 | 8.8 | 8.5 | 8.5 | 8.4 | 8.3 |
| Alkalinity as CaCO3 (mg/L) | 219 | 217 | 218 | 209 | 197 | 215 | 179 | 142 | 189 | 203 | 191 |
| Silica as Si (mg/L) | - | - | - | - | - | 2.85 | 2.27 | 2.05 | 2.47 | - | - |
| Dissolved Organic Carbon (mg/L) | 4.64 | 4.23 | 4.44 | 4.72 | 6.29 | 5.18 | 4.85 | 8.42 | 9.06 | - | - |
| Inorganic Suspended Solids (mg/L) | 1 | 3 | 2 | 3 | 1 | 3 | 2 | 7 | 3 | 4 | 4 |
| Volatile Suspended Solids (mg/L) | 2 | 2 | 2 | 5 | 2 | 5 | 3 | 3 | 5 | 3 | 5 |
| Total Suspended Solids (mg/L) | 3 | 5 | 4 | 8 | 3 | 6 | 5 | 10 | 7 | 7 | 9 |
| Carlson Trophic State Index (Secchi)* | 41 | 50 | 45 | 55 | 45 | 50 | 46 | 44 | 54 | 54 | 53 |
| Carlson Trophic State Index (Chl a)* | 46 | 48 | 47 | 58 | 62 | 63 | 48 | 56 | 63 | 61 | 59 |
| Carlson Trophic State Index (TP)* | 57 | 56 | 56 | 54 | 54 | 57 | 55 | 59 | 59 | 62 | 66 |
| *Index values generally range between 0 and 100, with increasing values indicating more eutrophic conditions. |