| Report Year: 2009 |
| Blue Lake, Monona County |
| Summary Data Table |
| Parameter | 6/10/2009 | 7/15/2009 | 2009 | 2007 | 2006 | 2005 | 2004 | 2003 | 2002 | 2001 | 2000 |
| Lake Depth (m) | 2.4 | 2.6 | 2.5 | 2.7 | 2.2 | 3.5 | 3.0 | 2.7 | 3.4 | 3.1 | 3.0 |
| 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) | 0.5 | 0.5 | 0.5 | 1.4 | 0.3 | 0.4 | 0.4 | 0.3 | 0.4 | 0.5 | 0.4 |
| Temperature(oC) | 19.7 | 26.2 | 22.9 | 26.0 | 26.3 | 24.4 | 22.5 | 25.9 | 26.3 | 22.5 | 26.6 |
| Dissolved Oxygen (mg/L) | 8.2 | 8.8 | 8.5 | 9.0 | 9.2 | 8.3 | 10.6 | 8.6 | 8.2 | 11.1 | 11.3 |
| Dissolved Oxygen Saturation (%) | 89 | 109 | 99.3 | 110.9 | 113.7 | 99.5 | 122.3 | 102.6 | 103.6 | 124.2 | 140.7 |
| Specific Conductivity (μS/cm) | 680.0 | 690.0 | 685.0 | 627.3 | 740.3 | 750.1 | 656.8 | 684.1 | 707.1 | 600.1 | 767.0 |
| Turbidity (NTU) | 20.9 | 127.7 | 74.3 | 6.9 | 30.7 | 36.5 | 37.6 | 30.9 | 30.1 | 32.4 | 26.4 |
| Chlorophyll a (μg/L) | 15.0 | 31.0 | 23.0 | 14.2 | 43.7 | 80.6 | 44.3 | 17.5 | 31.4 | 35.2 | 39.3 |
| Total Phosphorus as P (μg/L) | 43 | 104 | 73 | 63 | 113 | 77 | 90 | 85 | 73 | 124 | 123 |
| SRP as P (μg/L) | - | 1 | 1 | 7 | 2 | 2 | 3 | 4 | 5 | - | - |
| Total Nitrogen as N (mg/L) | 0.28 | 4.34 | 2.21 | 0.96 | 1.29 | 0.97 | 1.05 | 0.93 | 0.90 | 1.20 | 1.25 |
| (Phenate)Ammonia Nitrogen (NH3 + NH4+) as N (μg/L) | 100 | 16 | 54 | 275 | 58 | 23 | 16 | - | - | - | - |
| (Phenate)Ammonia Nitrogen (NH3) as N (un-ionized)(μg/L) | 16.3 | 1.6 | 9.0 | 38.4 | 6.6 | 2.3 | 1.8 | - | - | - | - |
| Nitrate + Nitrite (NO3 + NO2) as N (mg/L) | 0.12 | 0.12 | 0.12 | 0.12 | 0.16 | 0.12 | 0.12 | 0.12 | 0.12 | 0.12 | 0.12 |
| TN:TP ratio | 4 | 42 | 23 | 17 | 13 | 13 | 12 | 11 | 13 | 11 | 12 |
| pH | 8.7 | 8.7 | 8.7 | 8.6 | 8.4 | 8.4 | 8.5 | 8.4 | 8.4 | 8.2 | 7.9 |
| Alkalinity as CaCO3 (mg/L) | 292 | 286 | 289 | 260 | 304 | 296 | 245 | 194 | 286 | 225 | 298 |
| Silica as Si (mg/L) | - | - | - | - | - | 7.96 | 7.12 | 5.92 | 4.46 | - | - |
| Dissolved Organic Carbon (mg/L) | 9.50 | 8.72 | 9.11 | 6.10 | 7.28 | 4.36 | 5.90 | 9.68 | 9.32 | - | - |
| Inorganic Suspended Solids (mg/L) | 9 | 22 | 15 | 4 | 24 | 18 | 22 | 22 | 18 | 20 | 21 |
| Volatile Suspended Solids (mg/L) | 11 | 12 | 11 | 5 | 24 | 17 | 18 | 11 | 10 | 14 | 11 |
| Total Suspended Solids (mg/L) | 19 | 33 | 26 | 9 | 49 | 35 | 40 | 33 | 28 | 34 | 31 |
| Carlson Trophic State Index (Secchi)* | 70 | 72 | 71 | 55 | 76 | 72 | 73 | 76 | 73 | 69 | 72 |
| Carlson Trophic State Index (Chl a)* | 57 | 64 | 61 | 57 | 68 | 74 | 68 | 59 | 64 | 66 | 67 |
| Carlson Trophic State Index (TP)* | 58 | 71 | 66 | 64 | 72 | 67 | 69 | 68 | 66 | 74 | 73 |
| *Index values generally range between 0 and 100, with increasing values indicating more eutrophic conditions. |