| Report Year: 2011 |
| Five 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) | 5.1 | 5.8 | 5.5 | 5.5 | 6.0 | 5.8 | 5.9 | 5.6 | 6.2 | 6.3 | 6.0 | 5.2 | 5.9 | 5.4 |
| Thermocline Depth (m) | Nil | 4.0 | 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) | 0.5 | 0.5 | 0.3 | 0.4 | 0.4 | 0.5 | 0.4 | 0.5 | 0.6 | 0.7 | 0.5 | 0.6 | 1.4 | 0.8 |
| Temperature(oC) | 19.8 | 28.2 | 23.7 | 23.9 | 23.2 | 21.9 | 23.7 | 24.2 | 24.6 | 22.6 | 21.9 | 23.3 | 23.2 | 24.8 |
| Dissolved Oxygen (mg/L) | 10.1 | 9.5 | 10.0 | 9.9 | 8.1 | 7.3 | 7.4 | 8.9 | 9.9 | 9.7 | 9.6 | 8.3 | 8.8 | 8.4 |
| Dissolved Oxygen Saturation (%) | 111 | 122 | 119 | 117.2 | 94.7 | 83.5 | 87.5 | 106.5 | 121.4 | 112.6 | 110.8 | 97.0 | 103.4 | 101.0 |
| Specific Conductivity (μS/cm) | 470.0 | 400.0 | 300.0 | 390.0 | 396.7 | 436.7 | 464.7 | 498.8 | 478.2 | 452.0 | 470.7 | 476.5 | 444.3 | 418.8 |
| Turbidity (NTU) | 14.4 | 20.7 | 41.1 | 25.4 | 19.2 | 22.7 | 41.2 | 55.2 | 28.2 | 32.4 | 29.7 | 30.2 | 35.2 | 14.7 |
| Chlorophyll a (μg/L) | 39.1 | 77.1 | 214.2 | 110.2 | 62.5 | 20.7 | 38.0 | 34.0 | 95.5 | 45.4 | 30.8 | 32.0 | 17.4 | 23.3 |
| Total Phosphorus as P (μg/L) | 58.9 | 80.4 | 127.8 | 89.0 | 79.3 | 95.6 | 125 | 67 | 104 | 76 | 69 | 94 | 79 | - |
| SRP as P (μg/L) | <11 | <11 | <11 | <11 | <8 | <9 | <1 | <1 | <1 | 1.1 | <1 | 2.3 | - | - |
| TKN (mg/L) | 3.9 | <0.5 | 3.5 | 2 | 1 | - | - | - | - | - | - | - | - | - |
| Total Dissolved Solids (g/L) | 0.3 | 0.3 | 0.2 | 0.3 | - | - | - | - | - | - | - | - | - | - |
| Total Nitrogen as N (mg/L) | - | - | - | - | - | 1.2 | 2.39 | 2.50 | 4.19 | 4.32 | 2.85 | 1.79 | 2.66 | 1.58 |
| (Phenate)Ammonia Nitrogen (NH3 + NH4+) as N (μg/L) | <145 | <145 | <145 | <145 | <136 | <130 | 172 | 37 | 108 | 103 | - | - | - | - |
| (Phenate)Ammonia Nitrogen (NH3) as N (un-ionized)(μg/L) | <PQL | <PQL | <PQL | <PQL | <PQL | <130 | 20 | 3 | 15 | 14 | - | - | - | - |
| Nitrate + Nitrite (NO3 + NO2) as N (mg/L) | 4.02 | 2.99 | <0.4 | 2 | 2 | - | 1.16 | 1.05 | 2.63 | 2.31 | 1.61 | 0.49 | 1.52 | 0.28 |
| TN:TP ratio | - | - | - | - | - | 13 | 23 | 36 | 44 | 54 | 40 | 19 | 63 | - |
| pH | 8.4 | 8.3 | 8.6 | 8.5 | 8.7 | 8.5 | 8.4 | 8.4 | 8.4 | 8.6 | 8.5 | 8.3 | 8.2 | 8.2 |
| Alkalinity as CaCO3 (mg/L) | 203 | 161 | 120 | 161 | 138 | 165 | 173 | 190 | 183 | 140 | 126 | 163 | 135 | 180 |
| Silica as Si (mg/L) | - | - | - | - | - | - | - | - | 3.55 | 3.23 | 2.35 | 3.25 | - | - |
| Dissolved Organic Carbon (mg/L) | <7.6 | <7.6 | <7.6 | <7.6 | <6.4 | 8 | 20.14 | 5.90 | 6.70 | 23.14 | 12.22 | 14.12 | - | - |
| Inorganic Suspended Solids (mg/L) | 18 | 16 | 12 | 15 | 11 | 13 | 25 | 12 | 15 | 11 | 15 | 17 | 10 | 12 |
| Volatile Suspended Solids (mg/L) | 9 | 15 | <8 | 9 | 13 | 10 | 21 | 11 | 15 | 13 | 10 | 9 | 7 | 8 |
| Total Suspended Solids (mg/L) | 27 | 30 | 15 | 24 | 24 | 23 | 46 | 23 | 30 | 23 | 24 | 26 | 16 | 20 |
| Carlson Trophic State Index (Secchi)* | 69 | 70 | 79 | 72 | 73 | 70 | 73 | 69 | 69 | 66 | 70 | 69 | 56 | 63 |
| Carlson Trophic State Index (Chl a)* | 67 | 73 | 83 | 77 | 71 | 60 | 66 | 65 | 75 | 68 | 64 | 65 | 59 | 61 |
| Carlson Trophic State Index (TP)* | 63 | 67 | 74 | 69 | 67 | 70 | 74 | 65 | 71 | 67 | 65 | 70 | 67 | - |
| *Index values generally range between 0 and 100, with increasing values indicating more eutrophic conditions. |