| Report Year: 2009 |
| Lake Ahquabi, Warren County |
| Summary Data Table |
| Parameter | 6/18/2009 | 7/20/2009 | 2009 | 2007 | 2006 | 2005 | 2004 | 2003 | 2002 | 2001 | 2000 |
| Lake Depth (m) | 5.5 | 5.4 | 5.5 | 5.5 | 4.5 | 5.7 | 5.7 | 5.7 | 5.4 | 5.5 | 5.7 |
| Thermocline Depth (m) | 2.8 | 4.1 | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A |
| Secchi Disk Depth (m) | 0.9 | 0.9 | 0.9 | 1.2 | 1.8 | 0.8 | 0.9 | 1.4 | 1.8 | 1.5 | 1.0 |
| Temperature(oC) | 24.5 | 24.9 | 24.7 | 26.4 | 26.5 | 26.7 | 24.0 | 24.8 | 26.7 | 24.7 | 25.2 |
| Dissolved Oxygen (mg/L) | 10.7 | 5.4 | 8.1 | 9.5 | 9.2 | 9.3 | 9.9 | 9.9 | 10.4 | 11.0 | 9.0 |
| Dissolved Oxygen Saturation (%) | 129 | 65 | 96.8 | 118.3 | 114.4 | 116.3 | 117.5 | 120.4 | 133.7 | 133.5 | 109.1 |
| Specific Conductivity (μS/cm) | 220.0 | 220.0 | 220.0 | 226.7 | 302.7 | 247.7 | 225.9 | 223.0 | 261.0 | 203.8 | 214.5 |
| Turbidity (NTU) | 11.0 | 11.7 | 11.3 | 14.7 | 16.4 | 16.0 | 16.1 | 12.7 | 25.8 | 13.6 | 12.2 |
| Chlorophyll a (μg/L) | 33.0 | 12.0 | 22.5 | 46.2 | 28.9 | 106.1 | 32.5 | 23.5 | 30.6 | 19.4 | 10.6 |
| Total Phosphorus as P (μg/L) | 62 | 75 | 69 | 89 | 65 | 59 | 114 | 57 | 55 | 69 | 131 |
| SRP as P (μg/L) | 1 | - | 1 | 1 | 1 | 1 | 54 | 1 | 1 | - | - |
| Total Nitrogen as N (mg/L) | 1.08 | 1.36 | 1.22 | 1.34 | 0.99 | 0.89 | 5.06 | 1.04 | 0.87 | 1.02 | 2.03 |
| (Phenate)Ammonia Nitrogen (NH3 + NH4+) as N (μg/L) | 16 | 16 | 16 | 18 | 16 | 78 | 77 | - | - | - | - |
| (Phenate)Ammonia Nitrogen (NH3) as N (un-ionized)(μg/L) | 2.7 | 1.8 | 2.3 | 7.8 | 1.1 | 15.3 | 7.0 | - | - | - | - |
| Nitrate + Nitrite (NO3 + NO2) as N (mg/L) | 0.12 | 0.12 | 0.12 | 0.13 | 0.12 | 0.16 | 3.42 | 0.24 | 0.14 | 0.23 | 0.14 |
| TN:TP ratio | 17 | 18 | 18 | 18 | 17 | 14 | 37 | 20 | 17 | 16 | 15 |
| pH | 8.9 | 8.8 | 8.8 | 8.8 | 8.6 | 8.5 | 8.5 | 8.6 | 8.5 | 8.0 | 7.3 |
| Alkalinity as CaCO3 (mg/L) | 100 | 96 | 98 | 96 | 125 | 109 | 106 | 65 | 90 | 89 | 130 |
| Silica as Si (mg/L) | - | - | - | - | - | 3.44 | 4.98 | 1.85 | 1.64 | - | - |
| Dissolved Organic Carbon (mg/L) | 6.25 | 6.25 | 6.25 | 7.43 | 6.07 | 8.27 | 10.16 | 10.58 | 10.74 | - | - |
| Inorganic Suspended Solids (mg/L) | 3 | 10 | 6 | 4 | 2 | 4 | 4 | 3 | 4 | 2 | 2 |
| Volatile Suspended Solids (mg/L) | 7 | - | 7 | 16 | 5 | 8 | 6 | 4 | 5 | 5 | 3 |
| Total Suspended Solids (mg/L) | 10 | 8 | 9 | 20 | 7 | 10 | 10 | 8 | 9 | 7 | 5 |
| Carlson Trophic State Index (Secchi)* | 62 | 62 | 62 | 58 | 51 | 64 | 62 | 55 | 51 | 54 | 59 |
| Carlson Trophic State Index (Chl a)* | 65 | 55 | 61 | 68 | 64 | 76 | 65 | 62 | 64 | 60 | 54 |
| Carlson Trophic State Index (TP)* | 64 | 66 | 65 | 69 | 64 | 63 | 72 | 62 | 62 | 65 | 74 |
| *Index values generally range between 0 and 100, with increasing values indicating more eutrophic conditions. |