| Report Year: 2009 |
| Lake Geode, Henry County |
| Summary Data Table |
| Parameter | 6/16/2009 | 7/22/2009 | 2009 | 2007 | 2006 | 2005 | 2004 | 2003 | 2002 | 2001 | 2000 |
| Lake Depth (m) | 13.3 | 13.1 | 13.2 | 13.0 | 12.5 | 13.2 | 13.1 | 13.1 | 13.2 | 12.5 | 13.7 |
| Thermocline Depth (m) | 3.3 | 4.0 | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A |
| Secchi Disk Depth (m) | 1.4 | 2.2 | 1.8 | 1.1 | 1.6 | 4.3 | 3.4 | 4.6 | 2.5 | 2.3 | 1.4 |
| Temperature(oC) | 21.8 | 23.0 | 22.4 | 26.1 | 23.8 | 25.8 | 24.2 | 25.2 | 28.8 | 23.6 | 24.1 |
| Dissolved Oxygen (mg/L) | 11.8 | 7.6 | 9.7 | 11.9 | 10.0 | 10.4 | 11.0 | 11.6 | 9.8 | 11.5 | 8.5 |
| Dissolved Oxygen Saturation (%) | 134 | 88 | 111.1 | 146.4 | 117.6 | 128.5 | 131.3 | 142.5 | 130.6 | 139.4 | 101.5 |
| Specific Conductivity (μS/cm) | 330.0 | 300.0 | 315.0 | 279.6 | 350.8 | 432.4 | 360.4 | 338.8 | 347.7 | 273.9 | 249.8 |
| Turbidity (NTU) | 12.2 | 4.1 | 8.2 | 18.2 | 21.7 | 2.7 | 2.9 | 4.2 | 18.9 | 10.7 | 14.5 |
| Chlorophyll a (μg/L) | 13.0 | 7.0 | 10.0 | 42.0 | 48.4 | 9.2 | 12.4 | 7.3 | 6.7 | 10.9 | 7.3 |
| Total Phosphorus as P (μg/L) | 142 | 39 | 91 | 54 | 47 | 16 | 28 | 31 | 23 | 69 | 166 |
| SRP as P (μg/L) | 59 | - | 59 | - | - | - | 1 | 3 | 2 | - | - |
| Total Nitrogen as N (mg/L) | 5.43 | 3.27 | 4.35 | 2.54 | 2.30 | 3.13 | 2.34 | 2.00 | 4.07 | 4.41 | 1.86 |
| (Phenate)Ammonia Nitrogen (NH3 + NH4+) as N (μg/L) | 16 | 76 | 41 | 22 | 63 | 42 | 25 | - | - | - | - |
| (Phenate)Ammonia Nitrogen (NH3) as N (un-ionized)(μg/L) | 0.9 | 17.9 | 9.4 | 15.5 | 9.9 | 8.1 | 6.0 | - | - | - | - |
| Nitrate + Nitrite (NO3 + NO2) as N (mg/L) | 4.75 | 2.33 | 3.54 | 1.44 | 1.02 | 2.73 | 1.75 | 1.36 | 3.51 | 3.66 | 1.26 |
| TN:TP ratio | 38 | 83 | 61 | 50 | 52 | 193 | 89 | 64 | 176 | 229 | 22 |
| pH | 8.7 | 8.8 | 8.8 | 9.7 | 9.0 | 8.6 | 8.8 | 8.6 | 8.8 | 8.1 | 8.0 |
| Alkalinity as CaCO3 (mg/L) | 117 | 109 | 113 | 89 | 103 | 136 | 124 | 89 | 109 | 95 | 161 |
| Silica as Si (mg/L) | - | - | - | - | - | 2.03 | 1.55 | 1.20 | 1.29 | - | - |
| Dissolved Organic Carbon (mg/L) | 5.20 | 4.90 | 5.05 | 6.08 | 6.54 | 5.43 | 5.56 | 8.98 | 7.49 | - | - |
| Inorganic Suspended Solids (mg/L) | 8 | 2 | 5 | 3 | 2 | 2 | 1 | 1 | 3 | 4 | 5 |
| Volatile Suspended Solids (mg/L) | 3 | 3 | 3 | 7 | 6 | 2 | 3 | 2 | 4 | 2 | 3 |
| Total Suspended Solids (mg/L) | 11 | 5 | 8 | 10 | 9 | 5 | 5 | 2 | 6 | 4 | 8 |
| Carlson Trophic State Index (Secchi)* | 55 | 49 | 52 | 58 | 53 | 39 | 42 | 38 | 47 | 48 | 56 |
| Carlson Trophic State Index (Chl a)* | 56 | 50 | 53 | 67 | 69 | 52 | 55 | 50 | 49 | 54 | 50 |
| Carlson Trophic State Index (TP)* | 76 | 57 | 69 | 62 | 60 | 44 | 52 | 54 | 49 | 65 | 78 |
| *Index values generally range between 0 and 100, with increasing values indicating more eutrophic conditions. |