| Report Year: 2009 |
| Big Creek Lake, Polk County |
| Summary Data Table |
| Parameter | 6/15/2009 | 7/20/2009 | 2009 | 2007 | 2006 | 2005 | 2004 | 2003 | 2002 | 2001 | 2000 |
| Lake Depth (m) | 15.0 | 14.1 | 14.6 | 15.5 | 15.4 | 15.6 | 15.7 | 15.3 | 15.7 | 15.8 | 14.4 |
| Thermocline Depth (m) | Nil | Nil | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A |
| Secchi Disk Depth (m) | 2.7 | 2.8 | 2.7 | 2.3 | 2.5 | 3.1 | 1.9 | 3.1 | 2.8 | 2.3 | 1.2 |
| Temperature(oC) | 17.4 | 19.2 | 18.3 | 24.3 | 25.1 | 24.6 | 21.8 | 23.4 | 24.7 | 21.9 | 24.7 |
| Dissolved Oxygen (mg/L) | 7.3 | 3.3 | 5.3 | 8.9 | 7.9 | 10.8 | 8.4 | 9.0 | 8.7 | 7.7 | 6.6 |
| Dissolved Oxygen Saturation (%) | 76 | 35 | 55.8 | 108.2 | 96.1 | 130.4 | 95.6 | 104.4 | 104.6 | 87.0 | 79.0 |
| Specific Conductivity (μS/cm) | 600.0 | 610.0 | 605.0 | 441.5 | 518.0 | 571.3 | 459.7 | 518.9 | 458.4 | 446.7 | 345.5 |
| Turbidity (NTU) | 3.6 | 4.5 | 4.0 | 6.6 | 5.3 | 6.5 | 14.7 | 6.1 | 13.1 | 5.6 | 31.0 |
| Chlorophyll a (μg/L) | 3.0 | 2.0 | 2.5 | 12.0 | 11.8 | 19.1 | 9.5 | 7.8 | 17.4 | 11.9 | 5.7 |
| Total Phosphorus as P (μg/L) | 88 | 47 | 67 | 33 | 21 | 38 | 116 | 32 | 31 | 90 | 94 |
| SRP as P (μg/L) | 66 | 11 | 39 | 3 | - | 37 | 78 | 2 | 1 | - | - |
| Total Nitrogen as N (mg/L) | 8.36 | 7.74 | 8.05 | 10.88 | 7.00 | 10.47 | 10.27 | 12.05 | 6.02 | 9.31 | 2.08 |
| (Phenate)Ammonia Nitrogen (NH3 + NH4+) as N (μg/L) | 16 | 37 | 19 | 44 | 29 | 75 | 166 | - | - | - | - |
| (Phenate)Ammonia Nitrogen (NH3) as N (un-ionized)(μg/L) | 0.1 | 3.2 | 1.6 | 7.1 | 3.8 | 7.2 | 9.7 | - | - | - | - |
| Nitrate + Nitrite (NO3 + NO2) as N (mg/L) | 8.06 | 7.31 | 7.69 | 10.32 | 6.42 | 10.77 | 8.86 | 10.59 | 5.18 | 8.62 | 0.77 |
| TN:TP ratio | 95 | 165 | 130 | 404 | 416 | 302 | 207 | 402 | 210 | 129 | 24 |
| pH | 8.5 | 8.4 | 8.4 | 8.5 | 8.4 | 8.4 | 7.9 | 8.3 | 8.5 | 8.1 | 7.9 |
| Alkalinity as CaCO3 (mg/L) | 253 | 231 | 242 | 157 | 180 | 211 | 153 | 118 | 152 | 162 | 164 |
| Silica as Si (mg/L) | - | - | - | - | - | 8.85 | 8.62 | 4.46 | 2.02 | - | - |
| Dissolved Organic Carbon (mg/L) | 2.77 | 2.97 | <3.6 | <3.6 | <3.6 | 3.71 | <3.6 | 7.61 | 8.52 | - | - |
| Inorganic Suspended Solids (mg/L) | 2 | 3 | 3 | 3 | 3 | 4 | 6 | 2 | 4 | 4 | 1 |
| Volatile Suspended Solids (mg/L) | 1 | 1 | 1 | 3 | 2 | 3 | 3 | 3 | 4 | 2 | 2 |
| Total Suspended Solids (mg/L) | 3 | 4 | 3 | 6 | 5 | 7 | 10 | 5 | 9 | 6 | 4 |
| Carlson Trophic State Index (Secchi)* | 46 | 45 | 46 | 48 | 47 | 44 | 51 | 44 | 45 | 48 | 57 |
| Carlson Trophic State Index (Chl a)* | 41 | 37 | 40 | 55 | 55 | 60 | 53 | 51 | 59 | 55 | 48 |
| Carlson Trophic State Index (TP)* | 69 | 60 | 65 | 55 | 48 | 57 | 73 | 54 | 54 | 69 | 70 |
| *Index values generally range between 0 and 100, with increasing values indicating more eutrophic conditions. |