| Report Year: 2009 |
| Ingham Lake, Emmet County |
| Summary Data Table |
| Parameter | 6/3/2009 | 7/7/2009 | 2009 | 2007 | 2006 | 2005 | 2004 | 2003 | 2002 | 2001 | 2000 |
| Lake Depth (m) | 2.7 | 2.7 | 2.7 | 2.6 | 2.3 | 2.8 | 2.9 | 2.8 | 2.8 | 3.1 | 2.9 |
| Thermocline Depth (m) | Nil | 2.3 | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A |
| Secchi Disk Depth (m) | 0.4 | 0.4 | 0.4 | 0.3 | 0.3 | 0.3 | 0.3 | 0.3 | 0.4 | 0.9 | 0.4 |
| Temperature(oC) | 20.9 | 25.7 | 23.3 | 23.5 | 24.8 | 24.1 | 22.3 | 21.2 | 23.7 | 24.4 | 24.9 |
| Dissolved Oxygen (mg/L) | 10.7 | 13.2 | 12.0 | 7.8 | 11.7 | 10.0 | 9.6 | 9.1 | 9.7 | 8.6 | 8.6 |
| Dissolved Oxygen Saturation (%) | 120 | 162 | 140.9 | 92.4 | 142.1 | 118.1 | 110.0 | 101.7 | 114.6 | 102.4 | 104.0 |
| Specific Conductivity (μS/cm) | 460.0 | 450.0 | 455.0 | 407.0 | 428.0 | 421.6 | 461.5 | 446.2 | 545.0 | 545.9 | 446.3 |
| Turbidity (NTU) | 18.7 | 22.7 | 20.7 | 36.2 | 56.5 | 83.3 | 78.3 | 67.4 | 41.7 | 35.8 | 52.2 |
| Chlorophyll a (μg/L) | 61.0 | 31.0 | 46.0 | 74.2 | 53.1 | 362.5 | 135.9 | 31.0 | 86.0 | 72.4 | 60.5 |
| Total Phosphorus as P (μg/L) | 148 | 72 | 110 | 168 | 164 | 134 | 161 | 140 | 101 | 196 | 508 |
| SRP as P (μg/L) | 1 | - | 1 | 1 | 1 | - | 2 | 1 | 1 | - | - |
| Total Nitrogen as N (mg/L) | 2.34 | 2.42 | 2.38 | 2.01 | 2.83 | 2.74 | 2.77 | 3.15 | 2.29 | 2.15 | 2.82 |
| (Phenate)Ammonia Nitrogen (NH3 + NH4+) as N (μg/L) | 16 | - | 16 | 16 | 16 | 43 | 23 | - | - | - | - |
| (Phenate)Ammonia Nitrogen (NH3) as N (un-ionized)(μg/L) | 2.5 | - | 2.5 | 1.1 | 1.1 | 5.6 | 6.1 | - | - | - | - |
| Nitrate + Nitrite (NO3 + NO2) as N (mg/L) | 0.12 | 0.12 | 0.12 | 0.12 | 0.12 | 0.17 | 0.20 | 0.18 | 0.24 | 0.32 | 0.33 |
| TN:TP ratio | 16 | 143 | 80 | 13 | 19 | 21 | 19 | 23 | 23 | 13 | 7 |
| pH | 8.9 | 8.9 | 8.9 | 8.7 | 9.0 | 8.7 | 8.9 | 8.6 | 8.8 | 8.3 | 8.2 |
| Alkalinity as CaCO3 (mg/L) | 171 | 144 | 158 | 103 | 137 | 124 | 121 | 96 | 134 | 157 | 156 |
| Silica as Si (mg/L) | - | - | - | - | - | 9.93 | 8.76 | 10.47 | 8.76 | - | - |
| Dissolved Organic Carbon (mg/L) | 13.77 | 11.98 | 12.88 | 21.38 | 11.34 | 8.82 | 19.59 | 21.21 | 9.28 | - | - |
| Inorganic Suspended Solids (mg/L) | 10 | 2 | 6 | 9 | 17 | 8 | 17 | 11 | 11 | 4 | 83 |
| Volatile Suspended Solids (mg/L) | 22 | 27 | 24 | 30 | 30 | 30 | 35 | 29 | 25 | 11 | 42 |
| Total Suspended Solids (mg/L) | 32 | 29 | 30 | 41 | 48 | 35 | 51 | 40 | 24 | 14 | 126 |
| Carlson Trophic State Index (Secchi)* | 73 | 73 | 73 | 78 | 78 | 77 | 79 | 78 | 74 | 61 | 75 |
| Carlson Trophic State Index (Chl a)* | 71 | 64 | 68 | 73 | 70 | 88 | 79 | 64 | 74 | 73 | 71 |
| Carlson Trophic State Index (TP)* | 76 | 66 | 72 | 78 | 78 | 75 | 77 | 75 | 71 | 80 | 94 |
| *Index values generally range between 0 and 100, with increasing values indicating more eutrophic conditions. |