| Report Year: 2012 |
| Belva Deer Lake, Keokuk County |
| Summary Data Table |
| Parameter | 5/22/2012 | 7/11/2012 | 8/23/2012 | 2012 | 2011 | 2010 | 2009 | 2007 | 2006 | 2005 | 2004 | 2003 | 2002 | 2001 | 2000 |
| Lake Depth (m) | 11.8 | 11.3 | 11.6 | 11.6 | 11.5 | 11.7 | 11.7 | 11.5 | 11.2 | - | - | - | - | - | - |
| Thermocline Depth (m) | 3.4 | 2.7 | 5.0 | N/A | 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) | 1.6 | 0.8 | 1.5 | 1.3 | 1.5 | 1.2 | 1.9 | 2.9 | 2.9 | - | - | - | - | - | - |
| Temperature(oC) | 20.9 | 27.6 | 23.0 | 23.9 | 23.5 | 26.1 | 22.6 | 26.4 | 24.2 | - | - | - | - | - | - |
| Dissolved Oxygen (mg/L) | 9.5 | 6.8 | 7.5 | 7.9 | 8.4 | 10.9 | 7.3 | 8.2 | 7.7 | - | - | - | - | - | - |
| Dissolved Oxygen Saturation (%) | 107 | 86 | 87 | 93.1 | 98.9 | 135.0 | 84.4 | 102.8 | 92.0 | - | - | - | - | - | - |
| Specific Conductivity (μS/cm) | 240.0 | 230.0 | 250.0 | 240.0 | 230.0 | 216.7 | 256.7 | 255.7 | 327.4 | - | - | - | - | - | - |
| Turbidity (NTU) | 12.7 | 7.1 | 2.4 | 7.4 | 8.9 | 5.7 | 7.2 | 5.0 | 10.9 | - | - | - | - | - | - |
| Chlorophyll a (μg/L) | 22.3 | 20.0 | 7.8 | 16.7 | 20.7 | 13.6 | 20.3 | 7.1 | 4.5 | - | - | - | - | - | - |
| Total Phosphorus as P (μg/L) | 27.8 | 53.5 | 26.6 | 36.0 | 39.9 | 31.9 | 31.3 | 24 | 15 | - | - | - | - | - | - |
| SRP as P (μg/L) | <10 | <10 | <10 | <10 | <11 | <8 | <9 | <1 | <1 | - | - | - | - | - | - |
| TKN (mg/L) | 1.2 | 1.3 | 0.7 | 1 | 1 | 1 | - | - | - | - | - | - | - | - | - |
| Total Dissolved Solids (g/L) | 0.2 | 0.2 | 0.2 | 0.2 | 0.2 | - | - | - | - | - | - | - | - | - | - |
| Total Nitrogen as N (mg/L) | - | - | - | - | - | - | 1.6 | 1.47 | 0.79 | - | - | - | - | - | - |
| (Phenate)Ammonia Nitrogen (NH3 + NH4+) as N (μg/L) | 32.70 | <14 | <14 | <14 | <145 | <136 | <130 | 51 | <26 | - | - | - | - | - | - |
| (Phenate)Ammonia Nitrogen (NH3) as N (un-ionized)(μg/L) | 7 | <PQL | <PQL | <PQL | <PQL | <PQL | <130 | 6 | 2 | - | - | - | - | - | - |
| Nitrate + Nitrite (NO3 + NO2) as N (mg/L) | 0.33 | <0.06 | <0.06 | 0 | <0.4 | <0.5 | - | 0.76 | 0.12 | - | - | - | - | - | - |
| TN:TP ratio | - | - | - | - | - | - | 51 | 68 | 63 | - | - | - | - | - | - |
| pH | 8.8 | 8.6 | 8.5 | 8.6 | 8.5 | 9.0 | 8.5 | 8.6 | 8.4 | - | - | - | - | - | - |
| Alkalinity as CaCO3 (mg/L) | 105 | 97 | 110 | 104 | 99 | 87 | 108 | 118 | 150 | - | - | - | - | - | - |
| Silica as Si (mg/L) | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - |
| Dissolved Organic Carbon (mg/L) | 6.95 | 6.29 | 6.11 | 6 | <7.6 | <6.4 | 7 | 6.80 | 8.06 | - | - | - | - | - | - |
| Inorganic Suspended Solids (mg/L) | <2 | 5 | <2 | 2 | <5 | 5 | <4 | 2 | 5 | - | - | - | - | - | - |
| Volatile Suspended Solids (mg/L) | 4 | 5 | <3.2 | 4 | <8 | <9 | <8 | 3 | 4 | - | - | - | - | - | - |
| Total Suspended Solids (mg/L) | 4 | 11 | 3 | 6 | 8 | 10 | 7 | 5 | 9 | - | - | - | - | - | - |
| Carlson Trophic State Index (Secchi)* | 53 | 63 | 54 | 56 | 55 | 58 | 51 | 45 | 45 | - | - | - | - | - | - |
| Carlson Trophic State Index (Chl a)* | 61 | 60 | 51 | 58 | 60 | 56 | 60 | 50 | 45 | - | - | - | - | - | - |
| Carlson Trophic State Index (TP)* | 52 | 62 | 51 | 56 | 57 | 54 | 54 | 50 | 43 | - | - | - | - | - | - |
| *Index values generally range between 0 and 100, with increasing values indicating more eutrophic conditions. |