Environmental Science Water Resources 1

Question 1

What percentage of Earth's water is freshwater available for human use (in rivers, lakes, and accessible groundwater)?

Accepted Answer

About 1%

Answer

Only about 1% of Earth's water is accessible freshwater; the rest is saltwater, ice caps, or deep groundwater.

Question 2

Which U.S. law establishes the basic structure for regulating pollutant discharges into navigable waters?

Accepted Answer

Clean Water Act

Answer

The Clean Water Act (1972) set the framework for regulating discharge of pollutants and established water quality standards.

Question 3

What is an aquifer?

Accepted Answer

A layer of permeable rock or sediment that stores and transmits groundwater

Answer

An aquifer is an underground geological formation of permeable rock or sediment that holds and transmits significant quantities of groundwater.

Question 4

What is the primary cause of saltwater intrusion into coastal freshwater aquifers?

Accepted Answer

Over-pumping of groundwater

Answer

Excessive groundwater pumping lowers water table pressure, allowing denser saltwater from the ocean to move inland.

Question 5

Which watershed management concern arises when agricultural irrigation water evaporates, leaving minerals behind in soil?

Accepted Answer

Salinization

Answer

Salinization occurs when irrigation water evaporates and salts accumulate in topsoil, reducing agricultural productivity.

Environmental Science Practice Test