Water
Test date: Monday, February 11th
Chapter Three + LFS
Study Guide
Water Quality
Section One
Big Ideas:
1. Sources of drinking water include rivers, lakes, reservoirs, and groundwater.
2. Many communities maintain public water supplies to collect, treat, and distribute water to
residents. Some homes have private wells.
3. Generally, factors that affect water quality are cloudiness, odor, taste, acidity, hardness,
and presence of disease-causing organisms.
4. Most drinking water is treated to ensure that it is safe and appealing to drink.
5. Wastewater and sewage are treated to prevent contamination of drinking water.
6. Wastewater from sinks, showers, washing machines, and dishwaters can be recycled and
used for irrigation or flushing toilets is referred to as “gray water”
Steps for a typical water treatment process:
1. First filtration – filtered through screens
2. Coagulation – alum is added to create sticky flocs that settle to the bottom
3. Second Filtration – water trickles through sand or gravel (possibly charcoal)
4. Disinfection – chlorine is added to kill remaining organisms
5. Aeration – air is forced through to release gases, reduce unpleasant odors and taste
6. Additional Treatment – adding lime or sodium or fluoride may be added
Vocabulary:
Chlorinate- to treat with chlorine in order to purify as in sewage or water
Concentration- the amount of one substance in a certain volume of another substance
Water quality- the degree of purity of water, determined by measuring the substances in water besides
water molecules
Leach field – the ground area around a septic tank through which wastewater filters after leaving the
tank
Septic tank- an underground tank containing bacteria that treat wastewater as it passes it through
Filtration – the process of passing water through a series of screens that allow water through but not
larger solid particles
Sludge – deposits of fine solids that settle out from wastewater during the treatment process
Flocs – sticky globs created by adding a chemical such as alum during water treatment
Coagulation – the process by which particles in a liquid clump together; a step in the water treatment
process
Hardness – a measurement of calcium and magnesium
Disease-causing organisms- organisms that can affect water quality such as coliform or E coli
Section Three
Big Ideas:
1. Sources of water pollution include human and animal wastes(coliform), industrial (chemicals,
smoke and exhaust, heat), agricultural chemicals (pesticides and fertilizers), sediments, and
runoff from roads.
2. Leading cause of surface water pollution is from agricultural sources. A high level of nutrients is
likely to cause eutrophication, greatly reducing the amount of dissolved oxygen in a body of
water.
3. Acid rain is caused by sulfur and nitrogen from smokestacks and car exhausts, mainly from the
burning of fossil fuels. Acid rain level in PA is about 4.08 while an average rain would be about
5.6. Acid rain falling into a lake in PA would lower its pH, possibly hurting some of the fish that
live there.
4. According to World Health Organization (WHO), about 3 million people die every year, mostly
under the age of five, as a result of water pollutants.
Vocabulary:
pollutant- any substance that pollutes or impurifies
point source- a specific source of pollution that can be identified; easy to identify, monitor, and
regulate; examples- drain pipes, ditches, sewer lines)
nonpoint source- a widely spread source of pollution that is difficult to link to a specific point of
origin, such as road runoff; difficult to control; examples – atmospheric deposition,
agricultural/industrial /residential runoff
pH- how acidic or basic a substance is, measured on a scale of 1(very acidic)-14(very basic)
sewage- water containing human wastes
fertilizers – any substance added to the soil to make it more productive plant life
pesticides- chemicals intended to kill insects and other organisms that damage crops
phosphates –a chemical salt used in fertilizers
clear-cutting- the process of cutting down all trees in an area at once will increase sediments in
nearby water sources
biomagnification- the sequence of processes in an ecosystem by which higher concentrations of
a particular chemical, such as the pesticide DDT, are reached in organisms higher up on the food
chain through a series of predator-prey relationships
bioaccumulation – the increase in the concentration of a chemical in the tissue of an organism
over time.
acid rain- rain that is more acidic than normal
Review the many activities (lab, simulations, etc.) that we did in class. You can do this by
reviewing your notebook. If you kept an organized notebook.