NR1 4.03

Which statement best explains why water pollution problems have occurred for generations?

• People have always valued water mainly for recreation.

• People have regarded water as a means of disposing of wastes.

• Water naturally cleans itself instantly after contamination.

• Most communities lacked any source of fresh water.

According to the material, what determines the quality of water that is needed in a situation?

• The average annual rainfall of the region

• The specific use of the water

• The pH scale used by the laboratory

• The temperature of the water body

A factory discharging contaminants through a pipe into a river is best classified as which type of pollution?

• Diffuse source pollution

• Background pollution

• Point source pollution

• Thermal pollution

Which description matches diffuse source pollution?

• Direct introduction of contaminants at one identifiable location

• Contamination from natural sources unrelated to human activity

• Introduction of contaminants across a wide area that cannot be tied to a specific input location

• Release of heat from a power plant into a lake

Background pollution is characterized by which feature?

• It is primarily caused by industrial wastewater.

• It results from ongoing natural processes and is not associated with human activity.

• It occurs only in urban areas.

• It can always be traced to a single pipe discharge.

Detecting very low concentrations of specific chemicals in water, such as parts per million (ppm) or parts per billion (ppb), is possible under which conditions?

• Using only visual inspection outdoors

• In laboratories with specific equipment and tests

• By smelling the water sample

• By measuring river speed

What inexpensive method is available to everyone for examining water quality?

• Measuring water temperature daily

• Conducting an aquatic macroinvertebrate count

• Using a home pH strip kit only

• Evaporating a liter of water and weighing the residue

Which organism listed is classified as a Group 1 (pollution intolerant) indicator in streams?

• Leech

• Caddisfly

• Mosquito larva

• Aquatic worm

A student finds many stoneflies and mayflies during a biosurvey of a stream. What is the most reasonable conclusion about water quality at that site?

• The water is likely heavily polluted.

• Water quality cannot be inferred from organisms.

• The water is likely clean with low pollution.

• It indicates only chemical contamination, not overall quality.

Which statement best describes the purpose of stream biomonitoring as shown in the biosurvey image with nets?

• To add fish to the river to restore populations

• To collect organisms that indicate water quality levels

• To measure river depth only

• To test pH using laboratory chemicals