BIO EXAM

Why does saltwater intrusion occur? Earthquakes cause fractures in the bedrock, allowing saltwater to move inland. Coastal aquifers are depleted of freshwater, and saltwater can then flow in and contaminate the aquifer. Saltwater is more dense than freshwater, allowing it to flow into aquifers displacing the freshwater. Freshwater in coastal aquifers drain into the ocean, creating a void for saltwater to fill.

Coastal aquifers are depleted of freshwater, and saltwater can then flow in and contaminate the aquifer.

How does reducing consumption of certain goods also reduce consumers' water footprint? Consumer goods require water to produce, so reducing consumption reduces water use. Communities use less water to dispose of or recycle the goods they purchase. Consumers use less water to clean and maintain the goods they purchase. Consumers use less municipal water with reduced consumption of goods.

Consumer goods require water to produce, so reducing consumption reduces water use.

Arrange the steps that traditional wastewater treatment facilities use to turn wastewater into clean water in order from first to last.

First step Screens filter large matter from wastewater. Settling tanks hold wastewater so suspended solids fall to the bottom before workers discard the solids. Wastewater travels to sludge digester tanks, where workers add bacteria. In secondary settling tanks, bacteria continue to break down organic matter and suspended solids fall to the bottom. Wasterwater flows either to lagoons or to treatment tanks, where workers add chemicals to destroy pathogens and remove pollutants. Workers discharge effluent to the environment or send potable water to the local municipal water supply. Last step

What is the most likely reason for the pattern in Graph C?

Higher temperatures lead to increased evaporation, which reduces runoff efficiency.

Instead of using a traditional wastewater treatment facility to handle the sewage contaminating nearby Humboldt Bay, the California community of Arcata repurposed a retired landfill. What is one of the benefits of the "low‑tech" method Arcata, California uses to treat sewage? It is a completely natural process. It does not require a digester tank. It provides a habitat for wildlife. It does not generate any byproducts.

It provides a habitat for wildlife.

Although water covers approximately 75% of Earth's surface, only 2.5% of Earth's water is freshwater. Freshwater is essential to most of Earth's inhabitants, including humans. Arrange the freshwater sources on Earth from the largest to smallest by volume.

Largest by volume glaciers and ice caps groundwater ground ice and permafrost lakes and wetlands soil moisture atmosphere rivers living organisms Smallest by volume

The Safe Drinking Water Act (SDWA) has succeeded in protecting the water supplies of many communities across the United States. However, tens of thousands of violations still occur each year. Arrange the SDWA violations in order from those that occur most frequently to those that occur least frequently.

Most frequent violations possible fecal contamination disinfection by‑products arsenic nitrate lead and copper Least frequent violations

How did runoff efficiency change between 1906 and 2012?

Runoff efficiency remained above or near the data average until 1990 and then decreased below the average.

The average American uses approximately 140 gallons of water per day at home. This water is used in appliances or for personal care. Arrange the sources of domestic water consumption from the source of greatest consumption to least consumption.

Source of greatestwater consumption toilets showers faucets laundry leaks other tasks dishwashers Source of leastwater consumption

How did temperature in the region change between 1906 and 2012?

Temperature remained below or near the data average until 1990 and then rose above the average.

Which of these countries consume more water for domestic use than the global per capita average? United States Japan China Canada Uganda

United States Japan Canada

Given that oceans make up 97% of the water available on Earth, desalination treatments may be key to solving future water shortages. What are some complicating factors associated with desalination treatments?limited usage due to poor water qualityfinancial and energy expensesdisposal of brackish wastewaterlimited supply of raw materialundeveloped and unproven technology

financial and energy expenses disposal of brackish wastewater

Which industrial activity uses the most water in most developed countries? paper production production of electricity chemical manufacturing smelting

production of electricity

Hard surfaces, such as roads and buildings, prevent infiltration and groundwater recharge in urban and suburban areas. These hard surfaces also contribute to increased runoff, which can lead to flooding during heavy downpours. What are some ways to increase aquifer recharge in urban and suburban areas? increased grass landscaping storm drain maintenance rain gardens permeable pavement

rain gardens permeable pavement