| Report Year: 2011 |
| Little Spirit Lake, Dickinson County |
| Summary Data Table |
| Parameter | 6/1/2011 | 7/18/2011 | 8/29/2011 | 2011 | 2010 | 2009 | 2007 | 2006 | 2005 | 2004 | 2003 | 2002 | 2001 | 2000 |
| Lake Depth (m) | 2.8 | 2.8 | 2.5 | 2.7 | 2.8 | 2.7 | 2.6 | 2.8 | 3.0 | 2.5 | 2.6 | 2.6 | 2.8 | 2.4 |
| 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) | 0.4 | 0.7 | 0.3 | 0.5 | 1.3 | 1.2 | 0.4 | 0.5 | 0.9 | 1.3 | 1.1 | 0.6 | 0.9 | 0.3 |
| Temperature(oC) | 19.0 | 28.2 | 24.7 | 24.0 | 24.3 | 22.5 | 24.1 | 25.2 | 22.3 | 21.8 | 21.7 | 22.8 | 23.0 | 24.7 |
| Dissolved Oxygen (mg/L) | 11.0 | 16.1 | 10.5 | 12.5 | 9.0 | 9.2 | 13.8 | 16.3 | 8.8 | 10.1 | 10.3 | 7.8 | 9.8 | 8.1 |
| Dissolved Oxygen Saturation (%) | 118 | 207 | 126 | 150.3 | 107.7 | 106.6 | 168.7 | 201.0 | 100.8 | 113.9 | 115.3 | 90.9 | 115.4 | 98.3 |
| Specific Conductivity (μS/cm) | 390.0 | 410.0 | 390.0 | 396.7 | 440.0 | 523.3 | 419.1 | 467.4 | 500.5 | 549.3 | 548.3 | 635.4 | 524.5 | 487.5 |
| Turbidity (NTU) | 37.4 | 20.1 | 42.4 | 33.3 | 20.2 | 18.2 | 56.3 | 275.5 | 294.6 | 73.3 | 16.2 | 21.9 | 86.1 | 74.0 |
| Chlorophyll a (μg/L) | 63.4 | 66.8 | 60.2 | 63.5 | 48.0 | 11.3 | 179.8 | 101.3 | 186.8 | 56.5 | 26.4 | 49.7 | 56.4 | 44.9 |
| Total Phosphorus as P (μg/L) | 86.9 | 134.8 | 109.9 | 110.5 | 160.2 | 210.9 | 241 | 131 | 226 | 202 | 282 | 236 | 202 | - |
| SRP as P (μg/L) | <11 | <11 | <11 | <11 | <8 | 229.2 | 20.9 | 2.9 | 55.0 | 274.5 | 227.0 | 51.4 | - | - |
| TKN (mg/L) | 4.7 | <0.5 | 2.8 | 2 | 2 | - | - | - | - | - | - | - | - | - |
| Total Dissolved Solids (g/L) | 0.3 | 0.3 | 0.3 | 0.3 | - | - | - | - | - | - | - | - | - | - |
| Total Nitrogen as N (mg/L) | - | - | - | - | - | 1.8 | 2.58 | 2.29 | 3.19 | 2.66 | 2.70 | 2.46 | 4.12 | 2.14 |
| (Phenate)Ammonia Nitrogen (NH3 + NH4+) as N (μg/L) | <145 | 194.04 | <145 | <145 | <136 | <130 | <26 | <26 | 44 | 555 | - | - | - | - |
| (Phenate)Ammonia Nitrogen (NH3) as N (un-ionized)(μg/L) | <PQL | 30 | <PQL | <PQL | <PQL | <130 | 4 | 5 | 14 | 89 | - | - | - | - |
| Nitrate + Nitrite (NO3 + NO2) as N (mg/L) | <0.4 | <0.4 | <0.4 | <0.4 | <0.5 | - | 0.35 | 0.41 | 1.75 | 0.34 | 0.60 | 0.57 | 2.05 | 0.28 |
| TN:TP ratio | - | - | - | - | - | 10 | 13 | 19 | 14 | 15 | 10 | 10 | 27 | - |
| pH | 8.9 | 8.4 | 8.6 | 8.6 | 9.0 | 8.9 | 9.1 | 8.8 | 8.7 | 8.9 | 8.8 | 8.6 | 8.6 | 8.4 |
| Alkalinity as CaCO3 (mg/L) | 174 | 188 | 178 | 180 | 183 | 252 | 183 | 202 | 208 | 234 | 197 | 231 | 183 | 205 |
| Silica as Si (mg/L) | - | - | - | - | - | - | - | - | 10.07 | 6.43 | 8.40 | 9.78 | - | - |
| Dissolved Organic Carbon (mg/L) | <7.6 | 7.97 | 8.33 | 8 | 9 | 11 | 26.42 | 9.49 | 9.26 | 19.98 | 19.99 | 25.72 | - | - |
| Inorganic Suspended Solids (mg/L) | 7 | 13 | 9 | 10 | 10 | 5 | 9 | 14 | 6 | 9 | 13 | 9 | 9 | 32 |
| Volatile Suspended Solids (mg/L) | 10 | 11 | 10 | 10 | 9 | <8 | 25 | 14 | 12 | 9 | 7 | 9 | 7 | 13 |
| Total Suspended Solids (mg/L) | 17 | 24 | 19 | 20 | 19 | 10 | 34 | 28 | 18 | 17 | 21 | 18 | 17 | 45 |
| Carlson Trophic State Index (Secchi)* | 72 | 65 | 76 | 70 | 56 | 57 | 72 | 69 | 62 | 57 | 59 | 68 | 62 | 78 |
| Carlson Trophic State Index (Chl a)* | 71 | 72 | 71 | 71 | 69 | 54 | 82 | 76 | 82 | 70 | 63 | 69 | 70 | 68 |
| Carlson Trophic State Index (TP)* | 69 | 75 | 72 | 72 | 77 | 81 | 83 | 74 | 82 | 81 | 86 | 83 | 81 | - |
| *Index values generally range between 0 and 100, with increasing values indicating more eutrophic conditions. |