Water Sources Quality Standards Terms Ground water Hardness

Water Sources & Quality Standards

Terms Ø Ground water Ø Hardness Ø Surface water Ø Turbidity Ø Water quality

Sources of Water Ø Two main sources of water are surface water and ground water.

Surface Water Ø Can be found on the surface of the earth in lakes, streams, rivers, and oceans. Ø Can be either freshwater or saltwater. Ø Main source = precipitation. Ø Good for human consumption and agricultural use. Ø Surface water should be treated before use.

Groundwater Ø Water from within the earth. Ø May be located a few feet or thousands of feet within the earth. Provides much of the freshwater we use. Ø Can usually be used with little treatment. Ø

Water Quality Factors Ø Odor and Taste Ø Color Ø p. H Ø Hardness Ø Turbidity Ø Heavy Metals Ø Chemical Residues Ø Coliform Bacteria

Odor and Taste Ø Bad odor and taste in water may result from… Ø pollution, sulfur, or microorganisms

Color Ø For most people, clean, clear water is their first choice Ø However, colored water may be safe to drink Ø often the result of mineral presence. Ø Minerals that may change the color of water include: Ø iron, magnesium, and calcium Ø Other Ø factors…. sediment, organic matter, and plankton.

p. H Ø The p. H of water is commonly between 5. 5 to 8. 6

Hardness Ø The presence of calcium and magnesium ions in water Ø The greater the presence of these ions, the harder the water Ø Hard water leaves residue in hot water pipes and water heaters.

Turbidity Ø The solid material suspended in water Ø These materials may be soil particles or microscopic organisms. Ø To remove turbidity, the water has to be filtered and the particles allowed to settle

Heavy Metals Ø Including mercury and lead, may be hazardous to the water supply Ø Lead was once commonly used to seal joints, now that lead may leak into the water supply within the pipes. Ø These pipes should be replaced

Chemical Residues Ø Chemical residues from various chemicals including pesticides can be dangerous to human health. Ø However, the extent of these dangers is still unknown

Coliform Bacteria Ø An indication of fecal contamination in the water supply. Ø The contamination may result from human or animal waste getting into the water. Ø Water contaminated with coliform bacteria is not fit for consumption. Ø Coliform bacteria can be destroyed by boiling the water.

What to Test for and When? Ø Testing your household water supply is important to the health of everyone within the house. Ø Invisible contaminants in the water may be hazardous. Ø Visible contaminants can be harmful to both people and household items. Ø Other pollutants may not be harmful but may leave the water unfit to drink or cook with.

Testing Household Water Supplies Ø No matter the problem, water testing will help determine how to solve it. Ø Regular water tests that should be done on a yearly basis include coliform, nitrate, and p. H. Ø Regular water tests that should be done every three years include tests for sulfate, chloride, iron, manganese, and lead.

Testing Household Water Supplies Ø In special situations, water should be tested more frequently and more thoroughly. Ø Examples of such situations include the location of the water source to agricultural use, drilling, and landfills or dumps. Ø Each of these may be responsible for contamination to local water supplies.

Specific Areas of Testing Ø Bacteriological Ø Mineral Ø Chemical

Bacteriological testing Ø Determines the presence of bacteria that may cause disease. Ø The most common bacteria to test for is coliform.

Mineral Testing Ø Determines the level of mineral impurities in the water. Ø Large amounts of minerals can be hazardous and may reduce the usefulness of the water. Ø Common minerals to be tested for include calcium, iron, copper, zinc, manganese, and magnesium.

Chemical Testing Ø An expensive process, therefore it is usually only done when contamination is suspected. Ø Common chemical pollutants include petroleum products and agricultural and industrial chemicals.

Identifying & Reducing Water Pollution

What causes water pollution? n Can be from a number of sources Tanker full of chemicals spilling in ocean u OR…. u Invisible like acid rain u

Point source vs. Non-point source n Point source pollution –easily identifiable & can be easily stopped u Ex: wastewater from factories n Non-point source pollution – pollution that is not easily identifiable & may be from a number of sources. u Ex: runoff of water carrying pesticides from a farm field

What sources cause pollution? n Sediments – loose particles like sand, silt & clay n Pathogens – living & non-living organisms that cause disease n Thermal pollution n Wastes