| Report Year: 2011 |
| Lost Island Lake, Palo Alto County |
| Summary Data Table |
| Parameter | 5/31/2011 | 7/18/2011 | 8/29/2011 | 2011 | 2010 | 2009 | 2007 | 2006 | 2005 | 2004 | 2003 | 2002 | 2001 | 2000 |
| Lake Depth (m) | 3.9 | 3.8 | 3.5 | 3.7 | 4.0 | 3.9 | 3.9 | 3.9 | 4.1 | 3.8 | 4.0 | 3.8 | 3.8 | 3.7 |
| Thermocline Depth (m) | Nil | Nil | Nil | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A |
| Secchi Disk Depth (m) | 0.8 | 0.6 | 0.6 | 0.6 | 0.7 | 0.5 | 0.4 | 0.5 | 0.5 | 0.5 | 0.4 | 0.3 | 1.8 | 0.4 |
| Temperature(oC) | 19.4 | 27.9 | 23.4 | 23.6 | 24.2 | 21.7 | 22.9 | 22.0 | 22.7 | 21.5 | 21.4 | 20.0 | 22.7 | 24.1 |
| Dissolved Oxygen (mg/L) | 10.6 | 10.7 | 8.8 | 10.1 | 9.6 | 9.6 | 9.3 | 10.9 | 9.3 | 9.0 | 9.5 | 8.5 | 10.7 | 9.6 |
| Dissolved Oxygen Saturation (%) | 115 | 137 | 104 | 118.5 | 114.3 | 107.7 | 108.3 | 124.1 | 107.7 | 101.6 | 108.2 | 92.6 | 124.8 | 114.6 |
| Specific Conductivity (μS/cm) | 380.0 | 370.0 | 330.0 | 360.0 | 386.7 | 403.3 | 423.4 | 421.1 | 453.2 | 449.5 | 428.7 | 426.3 | 426.8 | 492.6 |
| Turbidity (NTU) | 17.9 | 21.4 | 34.4 | 24.6 | 9.2 | 14.9 | 29.4 | 45.1 | 33.5 | 64.4 | 28.7 | 72.4 | 36.1 | 37.9 |
| Chlorophyll a (μg/L) | 35.0 | 46.7 | 63.9 | 48.5 | 21.6 | 16.0 | 29.8 | 37.3 | 43.2 | 32.0 | 19.7 | 38.5 | 26.4 | 29.4 |
| Total Phosphorus as P (μg/L) | 57.7 | 85.8 | 96.6 | 80.0 | 81.0 | 97.7 | 76 | 79 | 65 | 76 | 75 | 102 | 109 | - |
| SRP as P (μg/L) | <11 | <11 | <11 | <11 | <8 | <9 | <1 | 1.3 | <1 | 2.5 | <1 | 3.7 | - | - |
| TKN (mg/L) | 1.0 | <0.5 | 2.0 | 1 | 1 | - | - | - | - | - | - | - | - | - |
| Total Dissolved Solids (g/L) | 0.3 | 0.2 | 0.2 | 0.2 | - | - | - | - | - | - | - | - | - | - |
| Total Nitrogen as N (mg/L) | - | - | - | - | - | 1.3 | 1.07 | 1.77 | 1.74 | 1.57 | 1.28 | 1.68 | 2.15 | 2.07 |
| (Phenate)Ammonia Nitrogen (NH3 + NH4+) as N (μg/L) | 154.63 | <145 | <145 | <145 | <136 | 243 | <26 | 42 | <26 | 66 | - | - | - | - |
| (Phenate)Ammonia Nitrogen (NH3) as N (un-ionized)(μg/L) | 16 | <PQL | <PQL | <PQL | <PQL | <130 | 2 | 4 | 2 | 5 | - | - | - | - |
| Nitrate + Nitrite (NO3 + NO2) as N (mg/L) | <0.4 | <0.4 | <0.4 | <0.4 | <0.5 | - | 0.15 | 0.13 | 0.27 | 0.16 | 0.14 | 0.22 | 0.31 | 0.23 |
| TN:TP ratio | - | - | - | - | - | 13 | 13 | 23 | 29 | 21 | 18 | 18 | 24 | - |
| pH | 8.5 | 8.4 | 8.6 | 8.5 | 8.8 | 8.7 | 8.6 | 8.6 | 8.5 | 8.6 | 8.5 | 8.3 | 8.2 | 8.3 |
| Alkalinity as CaCO3 (mg/L) | 184 | 174 | 149 | 169 | 170 | 185 | 183 | 186 | 228 | 178 | 135 | 186 | 167 | 165 |
| Silica as Si (mg/L) | - | - | - | - | - | - | - | - | 8.83 | 3.26 | 3.28 | 3.29 | - | - |
| Dissolved Organic Carbon (mg/L) | <7.6 | <7.6 | <7.6 | <7.6 | 7 | 10 | 11.40 | 10.36 | 12.30 | 13.15 | 14.09 | 13.78 | - | - |
| Inorganic Suspended Solids (mg/L) | 6 | 8 | 6 | 6 | 8 | 8 | 7 | 9 | 5 | 9 | 10 | 15 | 11 | 19 |
| Volatile Suspended Solids (mg/L) | <8 | 10 | 12 | 9 | 10 | 16 | 12 | 21 | 11 | 14 | 13 | 12 | 9 | 7 |
| Total Suspended Solids (mg/L) | 13 | 17 | 18 | 16 | 18 | 25 | 23 | 29 | 19 | 24 | 23 | 27 | 20 | 26 |
| Carlson Trophic State Index (Secchi)* | 64 | 67 | 69 | 67 | 66 | 70 | 73 | 70 | 70 | 71 | 73 | 77 | 52 | 72 |
| Carlson Trophic State Index (Chl a)* | 65 | 68 | 71 | 69 | 61 | 58 | 64 | 66 | 68 | 65 | 60 | 66 | 63 | 64 |
| Carlson Trophic State Index (TP)* | 63 | 68 | 70 | 67 | 68 | 70 | 67 | 67 | 64 | 67 | 66 | 71 | 72 | - |
| *Index values generally range between 0 and 100, with increasing values indicating more eutrophic conditions. |