NR1 4.03

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.

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

Diffuse source pollution

Background pollution

Point source pollution

Thermal 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

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.

Using only visual inspection outdoors

In laboratories with specific equipment and tests

By smelling the water sample

By measuring river speed

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

Leech

Caddisfly

Mosquito larva

Aquatic worm

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.

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