| Report Year: 2011 |
| Lake Hendricks, Howard County |
| Summary Data Table |
| Parameter | 6/8/2011 | 7/26/2011 | 9/7/2011 | 2011 | 2010 | 2009 | 2007 | 2006 | 2005 | 2004 | 2003 | 2002 | 2001 | 2000 |
| Lake Depth (m) | 4.0 | 3.5 | 4.0 | 3.8 | 3.9 | 4.0 | - | - | 4.9 | 5.1 | 5.1 | 5.0 | 5.1 | 4.8 |
| Thermocline Depth (m) | 2.9 | 2.1 | 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) | 2.7 | 0.5 | 0.5 | 1.2 | 0.7 | 0.9 | - | - | 0.8 | 1.1 | 1.8 | 0.9 | 1.5 | 2.0 |
| Temperature(oC) | 25.5 | 28.8 | 20.8 | 25.0 | 23.0 | 23.9 | - | - | 25.4 | 22.8 | 23.1 | 25.0 | 23.9 | 23.8 |
| Dissolved Oxygen (mg/L) | 11.2 | 20.9 | 8.8 | 13.6 | 9.0 | 10.1 | - | - | 11.8 | 12.1 | 13.4 | 11.7 | 15.0 | 10.4 |
| Dissolved Oxygen Saturation (%) | 136 | 271 | 98 | 168.4 | 106.3 | 119.7 | - | - | 143.7 | 141.2 | 157.4 | 144.0 | 180.7 | 124.1 |
| Specific Conductivity (μS/cm) | 300.0 | 280.0 | 260.0 | 280.0 | 270.0 | 250.0 | - | - | 269.1 | 326.8 | 277.0 | 344.1 | 268.4 | 319.7 |
| Turbidity (NTU) | 1.0 | 34.3 | 15.9 | 17.1 | 6.2 | 10.4 | - | - | 17.6 | 13.3 | 26.4 | 23.5 | 22.3 | 5.1 |
| Chlorophyll a (μg/L) | 5.9 | 156.5 | 110.6 | 91.0 | 34.3 | 30.0 | - | - | 167.3 | 41.8 | 17.5 | 68.2 | 41.7 | 18.2 |
| Total Phosphorus as P (μg/L) | 28.7 | 162.4 | 199.7 | 130.3 | 106.8 | 137.7 | - | - | 95 | 67 | 123 | 131 | 63 | - |
| SRP as P (μg/L) | <11 | <11 | <11 | <11 | <8 | <9 | - | - | <1 | 1.7 | 1.9 | 1.6 | - | - |
| TKN (mg/L) | 1.0 | 3.3 | 2.2 | 2 | 3 | - | - | - | - | - | - | - | - | - |
| Total Dissolved Solids (g/L) | 0.2 | 0.2 | 0.2 | 0.2 | - | - | - | - | - | - | - | - | - | - |
| Total Nitrogen as N (mg/L) | - | - | - | - | - | 2.1 | - | - | 3.04 | 9.44 | 3.07 | 1.49 | 4.51 | 5.29 |
| (Phenate)Ammonia Nitrogen (NH3 + NH4+) as N (μg/L) | <145 | <145 | <145 | <145 | 451 | <130 | - | - | 98 | 104 | - | - | - | - |
| (Phenate)Ammonia Nitrogen (NH3) as N (un-ionized)(μg/L) | <PQL | <PQL | <PQL | <PQL | <PQL | <130 | - | - | 36 | 21 | - | - | - | - |
| Nitrate + Nitrite (NO3 + NO2) as N (mg/L) | 3.85 | <0.4 | <0.4 | 1 | 2 | - | - | - | 1.76 | 8.52 | 1.70 | 0.26 | 3.88 | 3.54 |
| TN:TP ratio | - | - | - | - | - | 20 | - | - | 52 | 143 | 46 | 11 | 128 | - |
| pH | 8.8 | 9.9 | 7.8 | 8.8 | 8.8 | 9.3 | - | - | 9.3 | 8.8 | 9.3 | 9.2 | 9.3 | 7.4 |
| Alkalinity as CaCO3 (mg/L) | 91 | 78 | 79 | 83 | 88 | 82 | - | - | 87 | 86 | 61 | 82 | 74 | 107 |
| Silica as Si (mg/L) | - | - | - | - | - | - | - | - | 4.07 | 2.86 | 4.80 | 4.17 | - | - |
| Dissolved Organic Carbon (mg/L) | <7.6 | <7.6 | <7.6 | <7.6 | <6.4 | <6.2 | - | - | 6.64 | 5.43 | 8.76 | 10.80 | - | - |
| Inorganic Suspended Solids (mg/L) | <5 | <5 | <5 | <5 | <4 | 4 | - | - | 1 | 3 | 3 | 2 | 3 | 4 |
| Volatile Suspended Solids (mg/L) | <8 | 17 | 13 | 11 | <9 | 9 | - | - | 16 | 6 | 12 | 11 | 6 | 5 |
| Total Suspended Solids (mg/L) | <6 | 18 | 13 | 12 | 10 | 14 | - | - | 15 | 9 | 15 | 10 | 16 | 9 |
| Carlson Trophic State Index (Secchi)* | 46 | 71 | 72 | 57 | 65 | 62 | - | - | 63 | 58 | 52 | 62 | 54 | 50 |
| Carlson Trophic State Index (Chl a)* | 48 | 80 | 77 | 75 | 65 | 64 | - | - | 81 | 67 | 59 | 72 | 67 | 59 |
| Carlson Trophic State Index (TP)* | 53 | 78 | 81 | 74 | 72 | 75 | - | - | 70 | 65 | 74 | 74 | 64 | - |
| *Index values generally range between 0 and 100, with increasing values indicating more eutrophic conditions. |