| Report Year: 2011 |
| Thayer Lake, Union County |
| Summary Data Table |
| Parameter | 6/13/2011 | 8/1/2011 | 9/12/2011 | 2011 | 2010 | 2009 | 2007 | 2006 | 2005 | 2004 | 2003 | 2002 | 2001 | 2000 |
| Lake Depth (m) | 2.1 | 1.9 | 1.9 | 2.0 | 2.1 | 2.1 | - | - | 2.4 | 2.3 | 2.3 | 2.3 | 2.4 | 2.4 |
| Thermocline Depth (m) | 1.7 | Nil | Nil | 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) | 0.5 | 1.1 | 1.0 | 0.8 | 0.6 | 0.4 | - | - | 0.4 | 0.2 | 0.4 | 0.4 | 0.7 | 0.6 |
| Temperature(oC) | 21.6 | 30.3 | 23.0 | 25.0 | 24.6 | 24.1 | - | - | 25.3 | 22.9 | 24.3 | 27.1 | 24.2 | 26.5 |
| Dissolved Oxygen (mg/L) | 6.7 | 8.8 | 10.0 | 8.5 | 8.2 | 7.4 | - | - | 10.5 | 8.2 | 8.4 | 10.1 | 8.1 | 7.1 |
| Dissolved Oxygen Saturation (%) | 77 | 117 | 117 | 103.4 | 98.8 | 87.4 | - | - | 129.6 | 96.3 | 98.4 | 127.3 | 99.3 | 87.9 |
| Specific Conductivity (μS/cm) | 240.0 | 210.0 | 210.0 | 220.0 | 260.0 | 240.0 | - | - | 318.8 | 298.6 | 330.9 | 363.3 | 222.9 | 316.4 |
| Turbidity (NTU) | 21.3 | 8.1 | 7.9 | 12.4 | 24.0 | 27.0 | - | - | 320.6 | 135.9 | 49.1 | 23.1 | 40.6 | 133.0 |
| Chlorophyll a (μg/L) | 31.7 | 21.6 | 11.1 | 21.5 | 15.5 | 24.3 | - | - | 101.7 | 73.1 | 26.8 | 17.9 | 24.6 | 11.1 |
| Total Phosphorus as P (μg/L) | 94.1 | 77.5 | 66.8 | 79.5 | 114.7 | 97.4 | - | - | 100 | 178 | 130 | 84 | 139 | - |
| SRP as P (μg/L) | <11 | <11 | <11 | <11 | <8 | <9 | - | - | <1 | 16.2 | 8.0 | 3.3 | - | - |
| TKN (mg/L) | 2.2 | 1.2 | 2.6 | 2 | <0.5 | - | - | - | - | - | - | - | - | - |
| Total Dissolved Solids (g/L) | 0.2 | 0.1 | 0.1 | 0.1 | - | - | - | - | - | - | - | - | - | - |
| Total Nitrogen as N (mg/L) | - | - | - | - | - | 1.0 | - | - | 1.76 | 1.59 | 1.43 | 1.16 | 1.53 | 1.43 |
| (Phenate)Ammonia Nitrogen (NH3 + NH4+) as N (μg/L) | <145 | <145 | <145 | <145 | <136 | <130 | - | - | <26 | 211 | - | - | - | - |
| (Phenate)Ammonia Nitrogen (NH3) as N (un-ionized)(μg/L) | <PQL | <PQL | <PQL | <PQL | <PQL | <130 | - | - | 1 | 17 | - | - | - | - |
| Nitrate + Nitrite (NO3 + NO2) as N (mg/L) | <0.4 | <0.4 | <0.4 | <0.4 | <0.5 | - | - | - | 0.78 | 0.32 | 0.25 | 0.39 | 0.20 | 0.12 |
| TN:TP ratio | - | - | - | - | - | 10 | - | - | 18 | 9 | 12 | 15 | 12 | - |
| pH | 7.7 | 8.4 | 8.8 | 8.3 | 8.1 | 8.6 | - | - | 8.4 | 8.2 | 8.0 | 8.4 | 8.2 | 7.8 |
| Alkalinity as CaCO3 (mg/L) | 101 | 91 | 70 | 87 | 107 | 106 | - | - | 125 | 122 | 90 | 145 | 84 | 126 |
| Silica as Si (mg/L) | - | - | - | - | - | - | - | - | 6.18 | 11.60 | 4.31 | 2.99 | - | - |
| Dissolved Organic Carbon (mg/L) | <7.6 | <7.6 | <7.6 | <7.6 | 9 | 9 | - | - | 9.60 | 10.84 | 12.13 | 10.49 | - | - |
| Inorganic Suspended Solids (mg/L) | 11 | 8 | <5 | 8 | 10 | 10 | - | - | 12 | 48 | 26 | 8 | 13 | 15 |
| Volatile Suspended Solids (mg/L) | <8 | <8 | <8 | <8 | <9 | 9 | - | - | 10 | 16 | 11 | 7 | 5 | 13 |
| Total Suspended Solids (mg/L) | 19 | 15 | 8 | 14 | 18 | 19 | - | - | 22 | 64 | 36 | 15 | 18 | 28 |
| Carlson Trophic State Index (Secchi)* | 72 | 59 | 60 | 62 | 68 | 73 | - | - | 73 | 81 | 75 | 73 | 64 | 67 |
| Carlson Trophic State Index (Chl a)* | 64 | 61 | 54 | 61 | 57 | 62 | - | - | 76 | 73 | 63 | 59 | 62 | 54 |
| Carlson Trophic State Index (TP)* | 70 | 67 | 65 | 67 | 73 | 70 | - | - | 71 | 79 | 74 | 68 | 75 | - |
| *Index values generally range between 0 and 100, with increasing values indicating more eutrophic conditions. |