| Report Year: 2011 |
| Briggs Woods Lake, Hamilton County |
| Summary Data Table |
| Parameter | 6/6/2011 | 7/25/2011 | 9/6/2011 | 2011 | 2010 | 2009 | 2007 | 2006 | 2005 | 2004 | 2003 | 2002 | 2001 | 2000 |
| Lake Depth (m) | 8.9 | 9.1 | 8.9 | 8.9 | 9.1 | 8.6 | - | - | 9.0 | 9.0 | 9.2 | 8.6 | 8.7 | 9.1 |
| Thermocline Depth (m) | 4.3 | 2.3 | 2.7 | 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) | 4.0 | 1.0 | 0.7 | 1.9 | 1.5 | 2.7 | - | - | 3.4 | 1.2 | 1.5 | 2.5 | 1.7 | 1.8 |
| Temperature(oC) | 22.5 | 28.4 | 22.3 | 24.4 | 24.2 | 25.7 | - | - | 25.5 | 21.8 | 20.7 | 24.4 | 22.7 | 25.4 |
| Dissolved Oxygen (mg/L) | 10.5 | 8.7 | 9.1 | 9.4 | 11.0 | 9.2 | - | - | 14.2 | 17.0 | 14.6 | 11.0 | 15.5 | 10.8 |
| Dissolved Oxygen Saturation (%) | 121 | 112 | 105 | 112.6 | 130.6 | 113.6 | - | - | 174.2 | 193.2 | 164.0 | 133.6 | 180.5 | 131.4 |
| Specific Conductivity (μS/cm) | 340.0 | 260.0 | 270.0 | 290.0 | 296.7 | 320.0 | - | - | 600.3 | 538.4 | 541.0 | 645.6 | 514.4 | 393.1 |
| Turbidity (NTU) | 0.6 | 4.6 | 9.9 | 5.0 | 9.3 | 7.4 | - | - | 8.5 | 9.6 | 13.2 | 3.4 | 9.1 | 5.7 |
| Chlorophyll a (μg/L) | 10.0 | 44.0 | 28.3 | 27.4 | 22.1 | 15.7 | - | - | 37.5 | 63.1 | 23.6 | 20.1 | 6.4 | 14.0 |
| Total Phosphorus as P (μg/L) | 39.1 | 63.6 | 85.8 | 62.8 | 67.4 | 45.5 | - | - | 42 | 82 | 122 | 32 | 170 | - |
| SRP as P (μg/L) | <11 | <11 | <11 | <11 | <8 | <9 | - | - | <1 | <1 | <1 | <1 | - | - |
| TKN (mg/L) | 0.6 | 2.2 | 2.5 | 2 | 1 | - | - | - | - | - | - | - | - | - |
| Total Dissolved Solids (g/L) | 0.2 | 0.2 | 0.2 | 0.2 | - | - | - | - | - | - | - | - | - | - |
| Total Nitrogen as N (mg/L) | - | - | - | - | - | 1.2 | - | - | 13.65 | 12.65 | 10.98 | 13.37 | 15.15 | 3.85 |
| (Phenate)Ammonia Nitrogen (NH3 + NH4+) as N (μg/L) | <145 | <145 | <145 | <145 | <136 | <130 | - | - | 182 | 55 | - | - | - | - |
| (Phenate)Ammonia Nitrogen (NH3) as N (un-ionized)(μg/L) | <PQL | <PQL | <PQL | <PQL | <PQL | <130 | - | - | 21 | 14 | - | - | - | - |
| Nitrate + Nitrite (NO3 + NO2) as N (mg/L) | 0.50 | <0.4 | <0.4 | <0.4 | <0.5 | - | - | - | 13.14 | 11.63 | 9.27 | 14.13 | 16.12 | 2.41 |
| TN:TP ratio | - | - | - | - | - | 32 | - | - | 385 | 159 | 219 | 501 | 171 | - |
| pH | 8.7 | 9.4 | 7.8 | 8.6 | 9.0 | 8.9 | - | - | 8.3 | 8.8 | 8.4 | 8.5 | 8.3 | 7.8 |
| Alkalinity as CaCO3 (mg/L) | 150 | 122 | 106 | 126 | 135 | 134 | - | - | 205 | 167 | 121 | 178 | 142 | 143 |
| Silica as Si (mg/L) | - | - | - | - | - | - | - | - | 10.56 | 10.46 | 6.71 | 8.08 | - | - |
| Dissolved Organic Carbon (mg/L) | 8.33 | <7.6 | <7.6 | <7.6 | <6.4 | <6.2 | - | - | 5.69 | 4.91 | 7.72 | 7.18 | - | - |
| Inorganic Suspended Solids (mg/L) | <5 | <5 | <5 | <5 | <4 | 4 | - | - | 2 | 1 | 7 | 1 | 3 | 3 |
| Volatile Suspended Solids (mg/L) | <8 | <8 | <8 | <8 | <9 | <8 | - | - | 6 | 5 | 7 | 2 | 4 | 3 |
| Total Suspended Solids (mg/L) | <6 | 7 | 10 | 7 | 8 | 6 | - | - | 9 | 7 | 14 | 4 | 6 | 6 |
| Carlson Trophic State Index (Secchi)* | 40 | 61 | 65 | 51 | 54 | 46 | - | - | 42 | 58 | 55 | 47 | 52 | 52 |
| Carlson Trophic State Index (Chl a)* | 53 | 68 | 63 | 63 | 61 | 58 | - | - | 66 | 71 | 62 | 60 | 49 | 56 |
| Carlson Trophic State Index (TP)* | 57 | 64 | 68 | 64 | 65 | 59 | - | - | 58 | 68 | 73 | 54 | 78 | - |
| *Index values generally range between 0 and 100, with increasing values indicating more eutrophic conditions. |