| Report Year: 2011 |
| Williamson Pond, Lucas County |
| Summary Data Table |
| Parameter | 5/23/2011 | 7/11/2011 | 8/22/2011 | 2011 | 2010 | 2009 | 2007 | 2006 | 2005 | 2004 | 2003 | 2002 | 2001 | 2000 |
| Lake Depth (m) | 4.1 | 4.0 | 4.1 | 4.1 | 4.1 | 4.2 | - | - | 4.5 | 4.6 | 4.5 | 4.7 | - | 4.7 |
| Thermocline Depth (m) | 1.8 | 1.8 | 1.7 | 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) | 1.0 | 0.9 | 0.5 | 0.8 | 0.3 | 0.6 | - | - | 0.6 | 0.6 | 1.4 | 0.5 | - | 0.5 |
| Temperature(oC) | 20.4 | 26.8 | 27.5 | 24.9 | 25.1 | 25.7 | - | - | 26.2 | 23.7 | 24.7 | 26.7 | - | 23.9 |
| Dissolved Oxygen (mg/L) | 8.1 | 4.2 | 9.3 | 7.2 | 9.7 | 9.1 | - | - | 9.3 | 12.1 | 9.0 | 8.8 | - | 9.6 |
| Dissolved Oxygen Saturation (%) | 90 | 52 | 118 | 86.8 | 117.9 | 113.5 | - | - | 114.4 | 144.3 | 110.6 | 111.4 | - | 115.9 |
| Specific Conductivity (μS/cm) | 300.0 | 390.0 | 200.0 | 296.7 | 170.0 | 243.3 | - | - | 261.0 | 249.0 | 259.9 | 270.9 | - | 147.6 |
| Turbidity (NTU) | 9.0 | 1.2 | 32.4 | 14.2 | 29.8 | 22.4 | - | - | 59.4 | 40.7 | 37.1 | 31.5 | - | 99.0 |
| Chlorophyll a (μg/L) | 7.4 | 36.5 | 24.5 | 22.8 | 40.7 | 26.7 | - | - | 224.5 | 33.4 | 18.3 | 28.3 | - | 9.9 |
| Total Phosphorus as P (μg/L) | 85.7 | 126.4 | 311.0 | 174.4 | 211.4 | 220.8 | - | - | 262 | 159 | 207 | 160 | - | - |
| SRP as P (μg/L) | 21.7 | 26.0 | 125.3 | 125.3 | 48.9 | 81.1 | - | - | 187.6 | 81.9 | 91.0 | <1 | - | - |
| TKN (mg/L) | 1.5 | 1.2 | 1.8 | 2 | 2 | - | - | - | - | - | - | - | - | - |
| Total Dissolved Solids (g/L) | 0.2 | 0.3 | 0.1 | 0.2 | - | - | - | - | - | - | - | - | - | - |
| Total Nitrogen as N (mg/L) | - | - | - | - | - | 2.9 | - | - | 2.43 | 3.26 | 1.86 | 2.23 | - | 2.26 |
| (Phenate)Ammonia Nitrogen (NH3 + NH4+) as N (μg/L) | 271.71 | <145 | <145 | <145 | <136 | 185 | - | - | 51 | 218 | - | - | - | - |
| (Phenate)Ammonia Nitrogen (NH3) as N (un-ionized)(μg/L) | 5 | <PQL | <PQL | <PQL | <PQL | <130 | - | - | 17 | 20 | - | - | - | - |
| Nitrate + Nitrite (NO3 + NO2) as N (mg/L) | 3.86 | <0.4 | <0.4 | 1 | 1 | - | - | - | 1.03 | 1.77 | 0.31 | 1.22 | - | 0.27 |
| TN:TP ratio | - | - | - | - | - | 15 | - | - | 23 | 21 | 13 | 13 | - | - |
| pH | 7.7 | 8.3 | 7.6 | 7.8 | 8.1 | 8.6 | - | - | 9.0 | 8.4 | 8.3 | 8.3 | - | 7.3 |
| Alkalinity as CaCO3 (mg/L) | 102 | 91 | 103 | 99 | 66 | 102 | - | - | 97 | 98 | 79 | 94 | - | 127 |
| Silica as Si (mg/L) | - | - | - | - | - | - | - | - | 7.37 | 8.12 | 5.67 | 5.22 | - | - |
| Dissolved Organic Carbon (mg/L) | <7.6 | <7.6 | <7.6 | <7.6 | <6.4 | 8 | - | - | 10.98 | 9.29 | 13.27 | 13.11 | - | - |
| Inorganic Suspended Solids (mg/L) | 6 | 6 | <5 | <5 | 13 | 8 | - | - | 15 | 20 | 9 | 4 | - | 13 |
| Volatile Suspended Solids (mg/L) | <8 | <8 | 17 | <8 | <9 | 13 | - | - | 26 | 8 | 13 | 8 | - | 4 |
| Total Suspended Solids (mg/L) | 9 | 7 | 17 | 11 | 20 | 21 | - | - | 42 | 29 | 22 | 12 | - | 17 |
| Carlson Trophic State Index (Secchi)* | 60 | 62 | 71 | 63 | 76 | 67 | - | - | 67 | 67 | 56 | 69 | - | 69 |
| Carlson Trophic State Index (Chl a)* | 50 | 66 | 62 | 61 | 67 | 63 | - | - | 84 | 65 | 59 | 63 | - | 53 |
| Carlson Trophic State Index (TP)* | 68 | 74 | 87 | 79 | 81 | 82 | - | - | 84 | 77 | 81 | 77 | - | - |
| *Index values generally range between 0 and 100, with increasing values indicating more eutrophic conditions. |