| Report Year: 2009 |
| Oldham Lake, Monona County |
| Summary Data Table |
| Parameter | 6/11/2009 | 7/15/2009 | 2009 | 2007 | 2006 | 2005 | 2004 | 2003 | 2002 | 2001 | 2000 |
| Lake Depth (m) | 5.2 | 5.5 | 5.4 | 5.4 | 5.1 | 5.6 | 5.6 | 5.5 | 5.2 | 5.5 | 5.8 |
| Thermocline Depth (m) | 3.5 | 2.3 | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A |
| Secchi Disk Depth (m) | 1.4 | 0.9 | 1.1 | 1.7 | 1.5 | 1.5 | 1.1 | 2.1 | 1.3 | 1.7 | 1.8 |
| Temperature(oC) | 19.3 | 26.1 | 22.7 | 25.4 | 25.7 | 24.7 | 21.8 | 24.2 | 26.5 | 21.6 | 24.8 |
| Dissolved Oxygen (mg/L) | 9.1 | 10.2 | 9.6 | 8.0 | 8.5 | 8.9 | 10.3 | 10.2 | 9.0 | 11.5 | 9.2 |
| Dissolved Oxygen Saturation (%) | 98 | 126 | 112.2 | 97.3 | 103.8 | 107.7 | 117.7 | 118.5 | 111.4 | 127.2 | 111.0 |
| Specific Conductivity (μS/cm) | 420.0 | 430.0 | 425.0 | 493.5 | 419.8 | 443.7 | 389.2 | 398.4 | 378.4 | 361.3 | 374.2 |
| Turbidity (NTU) | 3.7 | 6.2 | 5.0 | 6.4 | 7.7 | 44.0 | 11.2 | 5.5 | 6.8 | 4.1 | 5.7 |
| Chlorophyll a (μg/L) | 7.0 | 38.0 | 22.5 | 12.2 | 32.4 | 45.2 | 45.8 | 18.6 | 15.3 | 22.6 | 15.6 |
| Total Phosphorus as P (μg/L) | 34 | 70 | 52 | 44 | 55 | 54 | 70 | 52 | 47 | 76 | 72 |
| SRP as P (μg/L) | - | 1 | 1 | 1 | 1 | 2 | 1 | 3 | 2 | - | - |
| Total Nitrogen as N (mg/L) | 0.78 | 1.04 | 0.91 | 0.44 | 1.24 | 0.94 | 0.97 | 0.90 | 0.78 | 1.23 | 1.10 |
| (Phenate)Ammonia Nitrogen (NH3 + NH4+) as N (μg/L) | - | 16 | 16 | 29 | 16 | 19 | 33 | - | - | - | - |
| (Phenate)Ammonia Nitrogen (NH3) as N (un-ionized)(μg/L) | - | 0.9 | 0.9 | 2.6 | 2.7 | 2.3 | 4.3 | - | - | - | - |
| Nitrate + Nitrite (NO3 + NO2) as N (mg/L) | 0.12 | - | 0.12 | 0.12 | 0.12 | 0.17 | 0.20 | 0.12 | 0.12 | 0.32 | 0.12 |
| TN:TP ratio | 23 | 15 | 19 | 11 | 25 | 18 | 14 | 19 | 17 | 19 | 19 |
| pH | 8.7 | 8.7 | 8.7 | 8.2 | 8.7 | 8.6 | 8.5 | 8.6 | 8.6 | 8.5 | 8.1 |
| Alkalinity as CaCO3 (mg/L) | 216 | 221 | 219 | 249 | 212 | 213 | 191 | 142 | 191 | 173 | 186 |
| Silica as Si (mg/L) | - | - | - | - | - | 3.63 | 2.72 | 2.94 | 1.72 | - | - |
| Dissolved Organic Carbon (mg/L) | 5.04 | 5.98 | 5.51 | 5.33 | 7.81 | <3.6 | 6.72 | 10.32 | 7.73 | - | - |
| Inorganic Suspended Solids (mg/L) | 3 | 2 | 3 | 3 | 3 | 2 | 3 | 4 | 4 | 3 | 1 |
| Volatile Suspended Solids (mg/L) | 3 | 6 | 5 | 4 | 5 | 2 | 7 | 4 | 4 | 3 | 3 |
| Total Suspended Solids (mg/L) | 6 | 9 | 7 | 7 | 9 | 5 | 10 | 8 | 7 | 7 | 4 |
| Carlson Trophic State Index (Secchi)* | 56 | 62 | 58 | 52 | 55 | 54 | 58 | 50 | 56 | 53 | 52 |
| Carlson Trophic State Index (Chl a)* | 50 | 66 | 61 | 55 | 65 | 68 | 68 | 59 | 57 | 61 | 58 |
| Carlson Trophic State Index (TP)* | 55 | 65 | 61 | 59 | 62 | 62 | 65 | 61 | 60 | 67 | 66 |
| *Index values generally range between 0 and 100, with increasing values indicating more eutrophic conditions. |