| Report Year: 2011 |
| Lake of the Hills, Scott County |
| Summary Data Table |
| Parameter | 6/21/2011 | 8/9/2011 | 9/20/2011 | 2011 | 2010 | 2009 | 2007 | 2006 | 2005 | 2004 | 2003 | 2002 | 2001 | 2000 |
| Lake Depth (m) | 6.0 | 5.6 | 5.9 | 5.8 | 6.0 | 5.8 | 5.9 | 5.7 | 6.2 | 5.8 | 6.1 | 6.2 | 6.3 | 5.9 |
| Thermocline Depth (m) | 2.0 | 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) | 0.7 | 0.6 | 0.5 | 0.6 | 0.6 | 0.8 | 0.7 | 0.9 | 0.8 | 0.6 | 0.9 | 0.6 | 1.2 | 0.7 |
| Temperature(oC) | 25.1 | 28.4 | 18.5 | 24.0 | 25.3 | 26.3 | 25.4 | 25.1 | 27.4 | 25.6 | 24.5 | 26.3 | 26.5 | 25.2 |
| Dissolved Oxygen (mg/L) | 11.3 | 6.3 | 7.3 | 8.3 | 8.1 | 10.1 | 7.4 | 9.2 | 8.6 | 11.3 | 7.5 | 10.9 | 12.5 | 4.2 |
| Dissolved Oxygen Saturation (%) | 137 | 81 | 78 | 98.6 | 98.2 | 126.2 | 89.5 | 111.5 | 109.3 | 139.3 | 88.9 | 138.9 | 155.2 | 50.8 |
| Specific Conductivity (μS/cm) | 430.0 | 380.0 | 380.0 | 396.7 | 390.0 | 393.3 | 369.3 | 500.2 | 492.8 | 399.2 | 414.3 | 557.4 | 416.2 | 417.1 |
| Turbidity (NTU) | 18.2 | 21.2 | 16.4 | 18.6 | 8.4 | 8.8 | 13.2 | 4.6 | 10.5 | 14.2 | 13.0 | 17.3 | 9.5 | 13.3 |
| Chlorophyll a (μg/L) | 25.7 | 34.9 | 65.1 | 41.9 | 19.1 | 53.7 | 32.1 | 20.5 | 38.5 | 50.3 | 22.5 | 36.6 | 13.0 | 4.4 |
| Total Phosphorus as P (μg/L) | 80.0 | 65.2 | 77.1 | 74.1 | 66.1 | 62.5 | 59 | 47 | 49 | 81 | 66 | 77 | 51 | - |
| SRP as P (μg/L) | <11 | <11 | <11 | <11 | <8 | <9 | <1 | 1.3 | <1 | <1 | <1 | <1 | - | - |
| TKN (mg/L) | 2.0 | 1.4 | 1.6 | 2 | 1 | - | - | - | - | - | - | - | - | - |
| Total Dissolved Solids (g/L) | 0.3 | 0.3 | 0.3 | 0.3 | - | - | - | - | - | - | - | - | - | - |
| Total Nitrogen as N (mg/L) | - | - | - | - | - | 1.1 | 1.19 | 1.04 | 0.97 | 4.68 | 1.26 | 1.25 | 1.57 | 1.27 |
| (Phenate)Ammonia Nitrogen (NH3 + NH4+) as N (μg/L) | <145 | <145 | <145 | <145 | <136 | <130 | 34 | <26 | 92 | 93 | - | - | - | - |
| (Phenate)Ammonia Nitrogen (NH3) as N (un-ionized)(μg/L) | <PQL | <PQL | <PQL | <PQL | <PQL | <130 | 4 | -1 | 9 | 13 | - | - | - | - |
| Nitrate + Nitrite (NO3 + NO2) as N (mg/L) | 1.11 | <0.4 | <0.4 | <0.4 | <0.5 | - | 0.20 | 0.12 | 0.17 | 3.50 | 0.28 | 0.44 | 0.69 | 0.23 |
| TN:TP ratio | - | - | - | - | - | 18 | 21 | 24 | 21 | 50 | 19 | 20 | 32 | - |
| pH | 8.6 | 8.4 | 8.2 | 8.4 | 8.5 | 8.7 | 8.6 | 8.4 | 8.4 | 8.6 | 8.5 | 8.5 | 8.4 | 7.2 |
| Alkalinity as CaCO3 (mg/L) | 164 | 145 | 124 | 144 | 152 | 145 | 137 | 174 | 177 | 148 | 110 | 145 | 150 | 150 |
| Silica as Si (mg/L) | - | - | - | - | - | - | - | - | 1.91 | 3.03 | 1.87 | 2.34 | - | - |
| Dissolved Organic Carbon (mg/L) | <7.6 | <7.6 | <7.6 | <7.6 | <6.4 | <6.2 | 4.78 | 5.44 | 7.61 | 3.92 | 7.29 | 7.00 | - | - |
| Inorganic Suspended Solids (mg/L) | <5 | <5 | <5 | <5 | 6 | <4 | 5 | 6 | 6 | 9 | 5 | 8 | 5 | 6 |
| Volatile Suspended Solids (mg/L) | 14 | 8 | 10 | 11 | <9 | 9 | 7 | 5 | 8 | 7 | 5 | 9 | 5 | 5 |
| Total Suspended Solids (mg/L) | 16 | 12 | 13 | 14 | 11 | 12 | 12 | 10 | 14 | 15 | 10 | 17 | 8 | 11 |
| Carlson Trophic State Index (Secchi)* | 66 | 69 | 70 | 68 | 67 | 63 | 65 | 62 | 64 | 67 | 62 | 67 | 58 | 65 |
| Carlson Trophic State Index (Chl a)* | 62 | 65 | 72 | 67 | 60 | 70 | 65 | 60 | 66 | 69 | 61 | 66 | 56 | 45 |
| Carlson Trophic State Index (TP)* | 67 | 64 | 67 | 66 | 65 | 64 | 63 | 60 | 60 | 67 | 64 | 67 | 61 | - |
| *Index values generally range between 0 and 100, with increasing values indicating more eutrophic conditions. |