| Report Year: 2009 |
| Littlefield Lake, Audubon County |
| Summary Data Table |
| Parameter | 7/13/2009 | 6/10/2009 | 2009 | 2007 | 2006 | 2005 | 2004 | 2003 | 2002 | 2001 | 2000 |
| Lake Depth (m) | 4.3 | 4.1 | 4.2 | 4.4 | 4.2 | 4.5 | 4.5 | 4.4 | 4.3 | 4.6 | 4.5 |
| Thermocline Depth (m) | 2.0 | 2.5 | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A |
| Secchi Disk Depth (m) | 0.6 | 0.3 | 0.5 | 0.4 | 0.5 | 0.5 | 0.6 | 1.2 | 0.4 | 0.5 | 0.7 |
| Temperature(oC) | 25.1 | 18.8 | 21.9 | 25.2 | 25.5 | 23.7 | 20.6 | 24.2 | 26.1 | 22.3 | 25.2 |
| Dissolved Oxygen (mg/L) | 12.8 | 6.2 | 9.5 | 10.9 | 7.7 | 9.3 | 8.8 | 8.7 | 12.1 | 9.7 | 7.4 |
| Dissolved Oxygen Saturation (%) | 155 | 67 | 111.0 | 135.2 | 94.0 | 109.1 | 98.8 | 103.1 | 148.7 | 103.1 | 90.4 |
| Specific Conductivity (μS/cm) | 330.0 | 320.0 | 325.0 | 264.7 | 295.3 | 294.1 | 276.9 | 289.5 | 246.9 | 232.6 | 261.9 |
| Turbidity (NTU) | 15.3 | 59.8 | 37.5 | 62.5 | 65.9 | 176.0 | 373.3 | 32.4 | 42.4 | 48.7 | 28.0 |
| Chlorophyll a (μg/L) | 43.0 | 7.0 | 25.0 | 129.2 | 48.4 | 133.0 | 36.7 | 27.2 | 85.6 | 104.0 | 17.0 |
| Total Phosphorus as P (μg/L) | 99 | 111 | 105 | 201 | 203 | 115 | 223 | 210 | 158 | 175 | 196 |
| SRP as P (μg/L) | 1 | 20 | 10 | 60 | 21 | 17 | 78 | 73 | 10 | - | - |
| Total Nitrogen as N (mg/L) | 1.96 | 1.40 | 1.68 | 2.57 | 1.55 | 2.12 | 3.78 | 2.92 | 1.43 | 2.29 | 1.81 |
| (Phenate)Ammonia Nitrogen (NH3 + NH4+) as N (μg/L) | 88 | 275 | 182 | 152 | 16 | 32 | 136 | - | - | - | - |
| (Phenate)Ammonia Nitrogen (NH3) as N (un-ionized)(μg/L) | 11.0 | 9.6 | 10.3 | 6.6 | 10.2 | 2.1 | 6.0 | - | - | - | - |
| Nitrate + Nitrite (NO3 + NO2) as N (mg/L) | 0.80 | 1.38 | 1.09 | 1.97 | 0.54 | 1.74 | 3.62 | 1.46 | 0.30 | 0.91 | 0.36 |
| TN:TP ratio | 20 | 13 | 16 | 21 | 12 | 21 | 44 | 35 | 9 | 18 | 11 |
| pH | 8.4 | 8.0 | 8.2 | 8.8 | 9.0 | 8.3 | 8.2 | 8.7 | 8.9 | 8.9 | 7.8 |
| Alkalinity as CaCO3 (mg/L) | 158 | 140 | 149 | 125 | 135 | 126 | 125 | 87 | 113 | 98 | 128 |
| Silica as Si (mg/L) | - | - | - | - | - | 5.59 | 19.74 | 4.41 | 3.37 | - | - |
| Dissolved Organic Carbon (mg/L) | 3.49 | 5.43 | 4.46 | 4.70 | 5.29 | 3.78 | 4.80 | 9.61 | 10.75 | - | - |
| Inorganic Suspended Solids (mg/L) | 10 | 22 | 16 | 17 | 12 | 14 | 121 | 10 | 8 | 10 | 7 |
| Volatile Suspended Solids (mg/L) | 9 | 9 | 9 | 21 | 18 | 12 | 29 | 14 | 18 | 15 | 8 |
| Total Suspended Solids (mg/L) | 19 | 31 | 25 | 38 | 30 | 26 | 150 | 25 | 26 | 24 | 15 |
| Carlson Trophic State Index (Secchi)* | 67 | 77 | 72 | 75 | 69 | 70 | 69 | 58 | 73 | 70 | 65 |
| Carlson Trophic State Index (Chl a)* | 67 | 50 | 62 | 78 | 69 | 79 | 66 | 63 | 74 | 76 | 58 |
| Carlson Trophic State Index (TP)* | 70 | 72 | 71 | 81 | 81 | 73 | 82 | 81 | 77 | 79 | 80 |
| *Index values generally range between 0 and 100, with increasing values indicating more eutrophic conditions. |