| Report Year: 2009 |
| Hannen Lake, Benton County |
| Summary Data Table |
| Parameter | 6/22/2009 | 7/27/2009 | 2009 | 2007 | 2006 | 2005 | 2004 | 2003 | 2002 | 2001 | 2000 |
| Lake Depth (m) | 5.5 | 6.2 | 5.9 | 5.9 | 6.1 | 6.3 | 6.4 | 6.0 | 6.2 | 6.0 | 6.5 |
| Thermocline Depth (m) | 1.5 | 3.1 | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A |
| Secchi Disk Depth (m) | 1.0 | 2.5 | 1.7 | 0.7 | 0.7 | 2.1 | 1.5 | 2.5 | 1.3 | 2.0 | 2.6 |
| Temperature(oC) | 26.8 | 24.4 | 25.6 | 26.3 | 24.2 | 26.5 | 24.7 | 24.5 | 25.7 | 24.1 | 25.3 |
| Dissolved Oxygen (mg/L) | 9.4 | 7.6 | 8.5 | 10.8 | 7.3 | 9.1 | 10.4 | 7.4 | 8.8 | 5.6 | 5.3 |
| Dissolved Oxygen Saturation (%) | 118 | 91 | 104.4 | 133.7 | 86.0 | 112.9 | 125.6 | 90.1 | 109.3 | 70.6 | 64.8 |
| Specific Conductivity (μS/cm) | 360.0 | 350.0 | 355.0 | 259.5 | 306.4 | 289.4 | 405.8 | 360.9 | 334.4 | 275.5 | 376.0 |
| Turbidity (NTU) | 12.2 | 0.5 | 6.4 | 27.5 | 23.0 | 5.9 | 11.7 | 4.3 | 71.5 | 12.9 | 6.1 |
| Chlorophyll a (μg/L) | 13.0 | 8.0 | 10.5 | 47.9 | 51.7 | 102.6 | 48.9 | 24.7 | 16.9 | 15.7 | 6.3 |
| Total Phosphorus as P (μg/L) | 84 | 77 | 81 | 104 | 128 | 88 | 75 | 74 | 227 | 132 | 146 |
| SRP as P (μg/L) | 9 | 21 | 15 | 1 | 18 | 1 | 6 | 12 | 5 | - | - |
| Total Nitrogen as N (mg/L) | 1.08 | 0.86 | 0.97 | 1.05 | 1.98 | 1.30 | 1.62 | 1.10 | 1.23 | 1.70 | 1.50 |
| (Phenate)Ammonia Nitrogen (NH3 + NH4+) as N (μg/L) | 145 | 56 | 101 | 19 | 316 | 129 | 51 | - | - | - | - |
| (Phenate)Ammonia Nitrogen (NH3) as N (un-ionized)(μg/L) | 20.2 | 8.2 | 14.2 | 5.3 | 73.3 | 29.9 | 9.1 | - | - | - | - |
| Nitrate + Nitrite (NO3 + NO2) as N (mg/L) | 0.12 | 0.12 | 0.12 | 0.12 | 0.12 | 0.13 | 0.31 | 0.15 | 0.15 | 0.18 | 0.13 |
| TN:TP ratio | 13 | 11 | 12 | 12 | 17 | 18 | 23 | 15 | 8 | 13 | 12 |
| pH | 8.4 | 8.5 | 8.4 | 9.0 | 8.8 | 9.0 | 8.7 | 8.2 | 8.4 | 8.0 | 7.2 |
| Alkalinity as CaCO3 (mg/L) | 173 | 164 | 169 | 116 | 130 | 125 | 144 | 114 | 138 | 148 | 164 |
| Silica as Si (mg/L) | - | - | - | - | - | 3.75 | 3.14 | 4.22 | 2.84 | - | - |
| Dissolved Organic Carbon (mg/L) | 5.98 | 5.53 | 5.76 | 7.47 | 9.44 | 7.26 | 6.67 | 10.22 | 10.21 | - | - |
| Inorganic Suspended Solids (mg/L) | 9 | 2 | 6 | 4 | 4 | 4 | 2 | 1 | 6 | 4 | 2 |
| Volatile Suspended Solids (mg/L) | 5 | 4 | 5 | 12 | 8 | 7 | 8 | 6 | 9 | 5 | 2 |
| Total Suspended Solids (mg/L) | 13 | 7 | 10 | 16 | 13 | 11 | 10 | 7 | 12 | 9 | 4 |
| Carlson Trophic State Index (Secchi)* | 60 | 47 | 52 | 65 | 65 | 50 | 54 | 47 | 56 | 50 | 46 |
| Carlson Trophic State Index (Chl a)* | 56 | 51 | 54 | 69 | 69 | 76 | 69 | 62 | 58 | 58 | 49 |
| Carlson Trophic State Index (TP)* | 68 | 67 | 67 | 71 | 74 | 69 | 66 | 66 | 82 | 75 | 76 |
| *Index values generally range between 0 and 100, with increasing values indicating more eutrophic conditions. |