ANALYTICAL REPORT for Bald Eagle Lake
TestAmerica Laboratories, Inc.
Samples collected 11/17/14
| Nitrate as N
| Fecal Coliform
WHAT WE TEST FOR
BOD (Biochemical Oxygen Demand)
Ammonia (desired: <0.3 mg/L)
Nitrogen is a product of the natural metabolism of plant and animal matter, and fertilizer runoff. Organic nitrogen can take many forms in water, including nitrate, nitrite, and ammonia. If ammonia is present in significant quantities, it can indicate that the water column does not have sufficient oxygen to oxidize ammonia to nitrite and nitrate. When available, all three of these nutrients can promote plant and algae growth when phosphate levels are sufficient. Ammonia concentrations below 0.3 mg/L significantly limit plant and algae populations in low phosphate lakes. Reduced fertilizer applications near shorelines can sometimes help prevent increases in these and other nutrient levels, but much of the ammonia and phosphate present in older lakes (5+ years) is recycled from the sediment. Both aeration and dredging can reduce this internal loading. Ammonia can be toxic to fish and other animals, and the toxicity is based on the total ammonia concentration, pH, and temperature.
Nitrate Nitrogen (desired: <05 mg/L)
Nitrate nitrogen generated by septic systems can emerge into the lake surface water.
The major impact of nitrates/nitrites is that of enrichment or fertilization called eutrophication. Nitrates stimulate the growth of algae and other plankton which provide food for higher organisms such as invertebrates and fish. An excess can cause over-production of plankton, which can dies and decompose as they use up the oxygen which causes other oxygen-dependent organisms to die.
Fertilizers containing either nitrogen or phosphorus should not be used on lawns near (within 400 feet of) the lake.
Total Phosphorus (desired: below 0.02 mg/L)
Total phosphorus measures all the forms of phosphorus, both dissolved and particulate. Ponds and lakes are categorized by their total phosphorus level and high phosphorus waters are considered polluted or “eutrophic”. Control of undesirable blue green algae can often be obtained at phosphorus levels below 0.02 mg/L.
BOD (desired: 3–5 mg/L)
Biochemical Oxygen Demand represents the amount of oxygen consumed by bacteria and other microorganisms while they decompose organic matter under aerobic conditions at a specified temperature.
1–2 mg/L Clean water with little organic waste
3–5 mg/L Moderately clean water with some organic waste
6–9 mg/L Lots of organic material and many bacteria<>10 mg/L Very poor water quality. Lots of organic material in the water
pH (Hydrogen ion concentration) (desired: <8.2 and 8.7)
pH values ranged between 8.2 and 8.7. These are normal values for a good quality southeast Michigan inland lake.
Lakes with extensive plant communities often have high summer pH values (greater than 9) because the plants use the carbonates in the water as a carbon source. This causes a decrease in the buffering capacity of the water, and allows the pH to rise.
Fecal Coliform(desired amount: < 300 colonies / 100 mL)
The presence of fecal coliform bacteria in lake water indicates that the water has been contaminated with fecal material of man or other animals. It may occur in lake water as a results of the the overflow of riparian septic systems. Its presence is an indicator for health risk to humans.