Question

how can we recognise whether water is polluted

Answer 1

if water boils absolutely at hundred degree Celsius then it is pure if it boils above or below 100 degree Celsius then it is polluted

Answer 2

$<b>Being able to recognize signs of potential water pollution is a critical skill people have developed over time in order to survive. Modern civilization has come to depend on municipal water treatment plants to provide a safe and plentiful supply of drinking water, so we don’t pay much attention to indications that our lakes, rivers and streams might be contaminated. In rural Kewaunee County, Wisconsin most people rely on private wells that draw from ground water reservoirs. The connection between surface waters and groundwater is a fundamental fact of the water cycle. If pollutants are discharged into streams, wetlands, and other waters those who rely on private wells could be at elevated health risk. Their water is rarely sampled or treated before they drink, cook, or bathe with it. They may only suspect a problem when a family member becomes sick or if the water is discolored or smells bad. Here are some recognized signs of potential water pollution: Dead Fish Obviously, dead or dying fish and other aquatic species is a clearcut sign that something’s not right with the water. Fish kills can result from the presence of toxic chemicals, eutrophication (lack of oxygen) or elevated levels of phosphorus or bacteria from agricultural runoff. Sometimes, it’s not even evidence of what you do see, but what you don’t see. Disappearance of frogs, crustaceans, salamanders or certain fish species can also mean the water environment is changing and these species have chosen to leave the area before they are killed. Discolored and Foul-smelling Water Any visible changes to your water supply should be investigated as soon as possible. Test your water annually, maybe more often if you live near a manure storage area. Although large-volume manure storage pits are claimed to be leak proof, court testimony by James Evans, Senior Agricultural Engineer for Maurer Statz, stated that 42 acres of manure ponds will leak “a little less than 1,000 gallons per day per acre.”  The degree and speed such leakage reaches ground water depends on the soil type, soil depth, crop cover and slope of the land where manure is stored or applied. Foam While foam on the water can be the result of decomposing naturally occuring organic materials, it can also be an indicator of a phosphorus overload caused by detergents or manure runoff. Foam is generally found on shorelines where wave action agitates the water or at the bottom of waterfalls or dams. The photo below was taken at the Silver Creek Dam near Bruemmerville Park west of Algoma in late November. We all drink the water, let’s all protect it.$