Key Water Quality Parameters:
adapted from “Key Sampling Parameters” fact sheet, Ohio EPA;
Michigan Water Standards
The presence of E.coli in water is an indication of animal waste contamination or human sewage. The State of Michigan has a standard for how much E.coli can be in surface water; less than 300/100ml for swimming or full body contact.(130/100ml as a 30 day geometric mean, May1st-Oct.31), and 1000/100ml partial body contact (year around).
E.coli is also an indicator organism of contaminated or unsafe water. They are monitored in surface waters because their presence indicates fecal contamination is present. Because it is not feasible to test for all the disease-causing organisms that can be present in surface water, Michigan uses E.coli as an indicator because it is commonly found in animal and human wastes. If E.coli is present above certain levels, then other disease causing organisms may be present and a potential threat to human health.
Infection by E.coli O157:H7, can cause the following health effects: severe bloody diarrhea and abdominal cramps; sometimes the infection causes non-bloody diarrhea. Often no fever is present. Symptoms usually appear in 2-4 days but can take up to 8 days. Most people recover without specific treatment in 5-10 days. Children under the age of five, the elderly and people whose health is weakened (long term illnesses such as cancer or AIDS) are at greatest risk for severe illness. In some people there is a complication called hemolytic uremic syndrome, in which the red blood cells are destroyed and the kidneys fail. About 2-7% of infections lead to this complication. In the United States hemolytic uremic syndrome is the principle cause of acute kidney failure in children, and most cases of hemolytic uremic syndrome is caused by E.coli O157:H7. With intensive care the death rate for hemolytic uremic syndrome is 3-5%.
E.coli can cause severe illness if ingested and is also an indicator of other disease causing organisms in water.
from Water Quality Parameters:
Total Phosphorus- Phosphorus is usually present in river water as phosphates, and is in very small amounts unless there has been human-caused enrichment of the water. The natural scarcity of phosphorus can be explained by its attraction to organic matter in soil particles. Generally the lower the total phosphorus value in the water, the better. Total phosphorus includes organic and inorganic phosphate. Phosphorus is considered to be a limiting factor in aquatic systems, meaning that it is not freely available for easy consumption by aquatic organisms. The amount of phosphates that water can hold without polluting it varies. In a river draining into a natural lake, the phosphate level should not exceed .05 mg/L. Natural lake level phosphates should not exceed .025 mg/L. A river that is not flowing into a lake should not exceed .1 mg/L. Phosphorus is the major contributing factor in the process of eutrophication. Inputs of phosphorus come from erosion, fertilizers, detergents, and the draining of wetlands.
Nitrates- Nitrogen is a much more abundant element in nature than phosphorus. Nitrogen is known to be an important plant nutrient, thus it is used often as a fertilizer and is found in high concentrations in agricultural runoff. Nitrate concentrations result from improperly functioning septic systems. As with phosphorus, too much nitrogen also contributes to eutrophication of lakes and streams. Nitrates in river water often ranges from 0.01 ppm to 3 ppm. Elevated concentrations (>0.10 mg/L) is indicative of the use of nitrate fertilizer, animal waste, or septic tank failure. The USEPA regulatory limit is 10 mg/L. Concentrations exceeding this limit may cause methemoglobinemia (bluebaby syndrome) in bottle-fed infants.
Biological Oxygen Demand (BOD)- Biological oxygen demand is a measure of the oxygen in the water that is required by aquatic life. When measured, BOD is the decrease in the oxygen content in milligrams per liter of a sample of water kept in the dark at a temperature of 20 degrees Celsius over a specified period of time. The difference between the initial DO level of the collected water and the final DO level is due to the consumption of oxygen brought about by the bacterial breakdown of organic material and the oxidation of chemicals in the water during the storage period. As a rule, BOD is measured after five days (BOD5) at room temperature. Rivers with high BOD have high nutrient levels in the water. Most of the oxygen is consumed by the organisms. Rivers with low BOD have low nutrient levels, therefore, much of the oxygen remains in the water. Unpolluted, natural waters will have a BOD of 5 mg/L or less.
Fecal Coliform- High counts of fecal coliform bacteria in rivers, streams and lakes are caused by contamination from the intestinal tract of humans and other warm-blooded animals. Fecal coliform bacteria are not in themselves harmful, but are associated with other bacteria and viruses which are, such as typhoid fever, hepatitis A, cholera, dysentery, shigellosis, etc. Coliform bacteria are indicator organisms used to indicate the presence of viruses and other pathogenic organisms. More than 1 fecal coliform colony indicates that the water supply may be vulnerable to contamination by human or other warm-blooded animal fecal waste. Fecal coliform bacteria live in the intestines of warm-blooded animals, but will acclimatize to warm water conditions.