water pollution

What is meant by water being the “universal solvent”?

Water can dissolve a wide array of substances, including many pollutants.

Why is water considered a disease vector?

It can carry and transmit pathogens that cause disease.

What is fecal coliform bacteria used to measure?

Water contamination from human or animal waste.

Where are fecal coliform bacteria found?

Human waste and animal waste.

What is an example of fecal coliform bacteria?

E. coli.

What level of fecal coliform bacteria is considered safe for drinking water?

100 colonies per 100 mL of water.

What level of fecal coliform bacteria is considered safe for swimming water?

Up to 200 colonies per 100 mL of water.

What does DO stand for?

Dissolved oxygen.

What is dissolved oxygen (DO)?

The amount of oxygen dissolved in water, measured in parts per million.

What does BOD stand for?

Biological oxygen demand.

What is biological oxygen demand (BOD)?

The amount of oxygen needed by bacteria to decompose organic material in water.

What happens to DO when BOD increases?

DO decreases because oxygen is used up by decomposers.

What is thermal pollution?

Pollution caused by excess heat released into water, often from power plants.

What is a major source of thermal pollution?

Power plants.

How does thermal pollution kill aquatic organisms?

Through thermal shock or by lowering dissolved oxygen levels.

Why does warm water have less dissolved oxygen than cold water?

Warm water cannot dissolve as much oxygen as cold water.

What does PPM stand for?

Parts per million.

What does PPM measure in water quality?

The concentration of a solute relative to the amount of solvent.

What is turbidity?

The cloudiness or lack of clarity in water caused by suspended particles.

What type of pollution causes high turbidity?

Sediment pollution from erosion.

How does high turbidity affect photosynthesis?

It reduces light penetration, lowering photosynthesis.

How does high turbidity affect water treatment plants?

It makes them work harder to treat water.

How does sediment pollution affect aquatic organisms?

It smothers invertebrates and disrupts food webs.

What is a point source of pollution?

Pollution from a single, specific, identifiable location.

Give an example of a point source of pollution.

A factory discharge pipe.

What is a nonpoint source of pollution?

Pollution released from a broad area with no single source.

Give examples of nonpoint pollution sources.

Farmland runoff, forestry runoff, feedlots.

What is an oxygen sag curve?

A graph showing how dissolved oxygen levels decrease and then recover downstream from a pollution source.

What causes the initial drop in DO on an oxygen sag curve?

An increase in BOD from organic waste entering the water.

What is cultural eutrophication?

The rapid enrichment of water with nutrients due to human activities.

What nutrients cause cultural eutrophication?

Nitrogen and phosphorus from fertilizers, livestock waste, and sewage.

What is the first step of cultural eutrophication?

Nutrients enter the water.

What is the second step of cultural eutrophication?

Algal blooms form.

What is the third step of cultural eutrophication?

Algae die.

What happens when dead algae decompose?

They are aerobically decomposed, consuming oxygen.

What condition results from oxygen depletion during eutrophication?

Hypoxia.

What happens to fish during hypoxia?

Fish die due to lack of oxygen.

How can cultural eutrophication be prevented?

Use less fertilizer and properly contain livestock waste.

How can eutrophication be cleaned up?

Mechanical weed removal and re-oxygenation of water.

How is groundwater polluted?

By pollutants that spill or seep into the ground.

Give examples of groundwater pollutants.

Solvents, cleaning chemicals, paint waste, heavy metals, coal ash.

How can coal ash pollute water?

It can leach into groundwater and rivers.

What is the best solution to groundwater pollution?

Prevention through proper construction and monitoring.

What are monitoring wells used for?

Detecting leaks and contamination in groundwater.

Can polluted groundwater be easily cleaned?

No, cleanup is usually impractical.

What does “the solution to pollution is dilution” mean?

Pollution spreads out in large bodies of water, reducing concentration.

Why do coastal areas suffer more from ocean pollution?

Pollution accumulates near shorelines where human activity is highest.

Can cultural eutrophication occur in oceans?

Yes.

What is a hypoxic or dead zone?

An area of water with very low oxygen where most life cannot survive.

What are colored tides?

Algal blooms that discolor water and may be toxic.

What are examples of colored tides?

Red tides, green tides, brown tides.

What are dredge spoils?

Material removed from waterways and dumped along or near coasts.

What are ocean garbage patches?

Large accumulations of floating plastic trapped in ocean gyres.

Where does most ocean garbage come from?

Cities, with a smaller amount from ships.

How does ocean garbage harm organisms?

Causes choking, intestinal blockage, or drowning through entanglement.

What was the Exxon Valdez oil spill?

A major oil spill in Alaska.

What was the BP Horizon oil spill?

An oil rig explosion and spill in the Gulf of Mexico.

How do oil spills harm waterfowl?

Oil coats feathers and disrupts buoyancy and insulation.

How do oil spills harm marine mammals?

Oil disrupts temperature regulation.

How do oil spills affect bottom-dwelling organisms?

They can be smothered.

How do oil spills affect the fishing industry?

Reduced fish populations hurt fishing.

How do oil spills affect recreation?

Polluted beaches and waters reduce tourism.

What is a mechanical method of oil spill cleanup?

Skimmers and booms.

What is a chemical method of oil spill cleanup?

Dispersants that break oil into smaller droplets.

What is a fire-based oil cleanup method?

Burning oil off the water, causing air pollution.

What is a natural oil cleanup method?

Wind, waves, and bacteria over time.

What is biological oil cleanup?

Bacteria breaking down oil naturally.

What did the Oil Pollution Act of 1990 require?

Funding for cleanup through taxes and double-hulled oil tankers.

What is ocean acidification?

The lowering of ocean pH due to dissolved CO₂.

How does CO₂ lower ocean pH?

CO₂ dissolves in water and forms carbonic acid.

What organisms are harmed by ocean acidification?

Corals and shell-forming organisms.

Why does low pH harm corals?

It interferes with calcium carbonate shell formation.

How are nonpoint surface water pollution sources best reduced?

Sustainable agriculture practices.

What is the Clean Water Act?

A law that sets limits on pollutant discharge into U.S. waters.

What does the Clean Water Act require of industries?

Permits that limit how much pollution they can discharge.

How does a septic system work?

Wastewater flows into a tank where solids settle and are decomposed, and liquids filter through soil.

What is primary sewage treatment?

Physical removal of large objects and settling of solids.

What is secondary sewage treatment?

Biological treatment where aerobic bacteria break down organic matter.

What is tertiary sewage treatment?

Removal of specific pollutants like nitrates and phosphates.

What is final sewage treatment?

Disinfection and bleaching using chlorine, ozone, or UV.

What is sewage sludge?

The solid waste containing bacteria, toxins, and heavy metals from treatment.

How can sewage sludge be disposed of?

Fertilizer, landfill, incineration, or ocean dumping (restricted).

What is the Safe Drinking Water Act?

A law regulating public drinking water quality.

Does the Safe Drinking Water Act apply to private wells?

No.

How can drinking water be purified in developing countries?

Solar disinfection, filters like LifeStraw, and chlorine.

Why is bottled water controversial?

It is expensive, less regulated, and causes environmental damage.

What environmental problems are caused by bottled water?

Landfills, litter, garbage patches, incineration, dioxins.

What can individuals do to reduce water pollution?

Use compost, minimize pesticides, don’t dump waste, don’t flush chemicals or oil.