| Report Year: 2009 |
| Briggs Woods Lake, Hamilton County |
| Summary Data Table |
| Parameter | 6/25/2009 | 7/30/2009 | 2009 | 2007 | 2006 | 2005 | 2004 | 2003 | 2002 | 2001 | 2000 |
| Lake Depth (m) | 9.2 | 7.6 | 8.4 | - | - | 9.0 | 9.0 | 9.2 | 8.6 | 8.7 | 9.1 |
| Thermocline Depth (m) | 1.8 | 3.1 | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A |
| Secchi Disk Depth (m) | 1.6 | 2.9 | 2.2 | - | - | 3.4 | 1.2 | 1.5 | 2.5 | 1.7 | 1.8 |
| Temperature(oC) | 27.4 | 25.2 | 26.3 | - | - | 25.5 | 21.8 | 20.7 | 24.4 | 22.7 | 25.4 |
| Dissolved Oxygen (mg/L) | 13.0 | 9.5 | 11.3 | - | - | 14.2 | 17.0 | 14.6 | 11.0 | 15.5 | 10.8 |
| Dissolved Oxygen Saturation (%) | 165 | 115 | 139.9 | - | - | 174.2 | 193.2 | 164.0 | 133.6 | 180.5 | 131.4 |
| Specific Conductivity (μS/cm) | 290.0 | 350.0 | 320.0 | - | - | 600.3 | 538.4 | 541.0 | 645.6 | 514.4 | 393.1 |
| Turbidity (NTU) | 13.6 | 7.1 | 10.4 | - | - | 8.5 | 9.6 | 13.2 | 3.4 | 9.1 | 5.7 |
| Chlorophyll a (μg/L) | 38.0 | 7.0 | 22.5 | - | - | 37.5 | 63.1 | 23.6 | 20.1 | 6.4 | 14.0 |
| Total Phosphorus as P (μg/L) | 74 | 34 | 54 | - | - | 42 | 80 | 123 | 32 | 169 | 129 |
| SRP as P (μg/L) | 1 | - | 1 | - | - | - | 1 | 1 | 1 | - | - |
| Total Nitrogen as N (mg/L) | 1.29 | 1.14 | 1.22 | - | - | 13.65 | 12.65 | 10.98 | 13.37 | 15.15 | 3.85 |
| (Phenate)Ammonia Nitrogen (NH3 + NH4+) as N (μg/L) | 16 | 42 | 27 | - | - | 182 | 54 | - | - | - | - |
| (Phenate)Ammonia Nitrogen (NH3) as N (un-ionized)(μg/L) | 8.2 | 15.3 | 11.7 | - | - | 20.9 | 14.1 | - | - | - | - |
| Nitrate + Nitrite (NO3 + NO2) as N (mg/L) | 0.12 | 0.12 | 0.12 | - | - | 13.05 | 11.54 | 9.32 | 14.13 | 16.12 | 2.40 |
| TN:TP ratio | 17 | 33 | 25 | - | - | 383 | 165 | 220 | 527 | 170 | 32 |
| pH | 9.5 | 9.0 | 9.3 | - | - | 8.3 | 8.8 | 8.4 | 8.5 | 8.3 | 7.8 |
| Alkalinity as CaCO3 (mg/L) | 125 | 143 | 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) | 5.05 | 5.63 | 5.34 | - | - | 5.69 | 4.91 | 7.72 | 7.18 | - | - |
| Inorganic Suspended Solids (mg/L) | 9 | 3 | 6 | - | - | 2 | 1 | 7 | 1 | 3 | 3 |
| Volatile Suspended Solids (mg/L) | 2 | 2 | 2 | - | - | 6 | 5 | 7 | 2 | 4 | 3 |
| Total Suspended Solids (mg/L) | 11 | 5 | 8 | - | - | 9 | 7 | 14 | 4 | 6 | 6 |
| Carlson Trophic State Index (Secchi)* | 53 | 45 | 48 | - | - | 42 | 58 | 55 | 47 | 52 | 52 |
| Carlson Trophic State Index (Chl a)* | 66 | 50 | 61 | - | - | 66 | 71 | 62 | 60 | 49 | 56 |
| Carlson Trophic State Index (TP)* | 66 | 55 | 62 | - | - | 58 | 67 | 74 | 54 | 78 | 74 |
| *Index values generally range between 0 and 100, with increasing values indicating more eutrophic conditions. |