Lecture 5: Water Resources and Pollution

Question 1

Importance of Water

Answer 1

➝ Found in every living organism.
➝ Dissolves and transports many molecules (nitrates, phosphates, minerals).
➝ Quickly moves between three phases, transferring it (and heat) between the surface, atmosphere, and around the planet.

Question 2

Distribution of Water

Answer 2

• Ocean 97%
• Freshwater 3%
  > Ice Caps and Glaciers 70%
  >Groundwater (Aquifers) 29%
  >Easily Accessible Freshwater 1%
  –> Lakes 52%
  –> Soil Moisture 38%
  –> Water Vapor 8%
  –> Rivers 1%
  –> Living Organisms 1%

Question 3

Movement processes of water.

Answer 3

Hydrologic/Water Cycle

Question 4

Liquid water is heated and converted to water vapor.

Answer 4

Evaporation

Question 5

Evaporation from leaves

Answer 5

transpiration

Question 6

Water vapor cools and liquefies.

Answer 6

condensation

Question 7

Water droplets combine and fall from clouds.

Answer 7

Precipitation

Question 8

Seeps through spaces in soil.

Answer 8

Infiltration

Question 9

Flows downhill to a stream, then a lake or ocean.

Answer 9

Runoff

Question 10

are underground formations of rock and sand that hold water.

Answer 10

Aquifers

Question 11

The uppermost boundary of aquifers is called the

Answer 11

water table

Question 12

is recharged from the ground surface directly above it.

Answer 12

unconfined aquifer

Question 13

has an impermeable layer of clay or rock that limits recharging to a smaller area.

Answer 13

confined aquifer

Question 14

the entire area of land where water runoff or infiltration
feeds a specific river

Answer 14

watershed

Question 15

Withdrawal and consumption of water for agriculture, drinking, etc

Answer 15

water use

Question 16

Amount of water diverted or removed from its source. A portion may be returned afterward.
Example:

Answer 16

Withdrawal
- Power plant coolant water

Question 17

Water is withdrawn AND permanently removed from a source.
Example:

Answer 17

Consumption
- Irrigation

Question 18

The three largest demands for water withdrawal include:

Answer 18

⇾ Power generation 38%: Coolant water and for generating steam.
⇾ Irrigation 39%: Watering crops.
⇾ Domestic 13%: Household water uses.
(others: industrial 6%, livestock 2%, mining 1%, commercial 1%)

Question 19

the largest consumer of water worldwide, as most of
it is either taken in by plants or evaporated into the atmosphere.

Answer 19

Irrigation

Question 20

__ occurs when the demand for water is greater than the supply. Leads to __.

Answer 20

water stress
- depletion of freshwater resources

Question 21

Regions with water stress tend to be:

Answer 21

• Naturally arid
• Heavily populated
• Growing water-intensive crops and animals.

Question 22

Environmental impacts of overconsumption of freshwater supplies:

Answer 22

⇾ Decrease in river flow.
⇾ Lowering of lake and reservoir levels.
⇾ Subsidence, or the gradual sinking of land.

Question 23

Alternative water sources and reducing water consumption

Answer 23

water conservation

Question 24

the removal of salt from ocean water, through two
possible methods: __, __

Answer 24

Desalination
- Distillation boils the water and collects the steam.
- Reverse osmosis passes pressurized water through a filter.

Question 25

Desalination produces a lot of salt waste called __.

Answer 25

brine

Question 26

The energy costs for desalination are __

Answer 26

very high

Question 27

Water conservation efforts focus on __, as it is the biggest source of water consumption. Give example practices.

Answer 27

agriculture ⇾ Installing drip irrigation systems for tree crops with high water demands. ⇾ Contour plowing and terracing to slow runoff and increase infiltration. ⇾ Lining irrigation canals to prevent leaks and block evaporation.

Question 28

Home water conservation centers around high-efficiency devices. Give examples.

Answer 28

- Low-flow showerheads and faucets use aerators to reduce water consumption. - Dual-flush toilets use less water for urine and more for solid waste. - Efficient dishwashers and washing machines run longer, but use much less water per cycle.

Question 29

uses drought-tolerant plants in the homes and yards in arid climates.

Answer 29

Xeriscaping

Question 30

recirculate used water from the sink or shower into the toilet or for yard irrigation.

Answer 30

Graywater systems

Question 31

From the Industrial Revolution until the passage of the __, surface waters were used as __.

Answer 31

- Clean Water Act in 1970 - industrial dumpsites

Question 32

The __ established rules and regulations for what can be discharged into surface waters The __ lists all impaired waters that do not meet one or more of the standards.

Answer 32

- Clean Water Act - EPA

Question 33

Causes of impaired waters

Answer 33

- Coliform Bacteria - heavy metals - Persistent Organic Pollutants (POPs) - Oxygen Depleting Pollution - Nutrient Pollution

Question 34

Disease-causing bacteria from untreated human sewage and manure.

Answer 34

Coliform bacteria

Question 35

Neurotoxins. Released by mining and the use of synthetic fertilizers.

Answer 35

Heavy metals

Question 36

Synthetic chemicals that do not degrade and are prone to biomagnification and bioaccumulation. “Forever chemicals.”

Answer 36

Persistent Organic Pollutants (POPs)

Question 37

Biodegradable matter consumed by decomposers, who deplete oxygen levels in the water.

Answer 37

Oxygen-Depleting Pollution

Question 38

Nitrogen and phosphorous-rich compounds that promote algae overgrowth.

Answer 38

Nutrient Pollution

Question 39

water pollution comes from a single, identifiable source. Examples.

Answer 39

Point source ➝ Factories ➝ Water treatment plants

Question 40

water pollution comes runoff or infiltration from a wide area. Examples.

Answer 40

Nonpoint source ➝ Agricultural fields ➝ City stormwater drains ➝ Home septic systems

Question 41

an increase in algae growth as fertilizer enters surface waters.

Answer 41

Cultural eutrophication

Question 42

Trophic classifications of aquatic ecosystems

Answer 42

- oligotrophic - mesotrophic - eutrophic - hypereutrophic

Question 43

Define oligotrophic and give examples of organisms present

Answer 43

* low nutrients * low turbidity * high sunlight Examples: - Zooplankton - Submerged plants - Fish - Benthos

Question 44

Define mesotrophic and give examples of organisms present

Answer 44

* Increasing nutrients, turbidity, and algae * Decreasing sunlight Examples: - More fish and zooplankton

Question 45

Define eutrophic and give examples of organisms present

Answer 45

* High nutrients * High turbidity * Hypoxia, reduced dissolved oxygen - death of submerged organisms

Question 46

refers to low oxygen levels in the water, which can be harmful to aquatic life.

Answer 46

hypoxia

Question 47

explain how the link between hypoxia and eutrophic

Answer 47

Nutrient Input: Eutrophication is typically triggered by the input of excessive nutrients, often from human activities such as agriculture runoff, sewage discharge, and the use of fertilizers. These nutrients, particularly nitrogen and phosphorus, act as fertilizers for aquatic plants and algae. Algal Blooms: The increased nutrient availability stimulates the rapid growth of algae and other aquatic plants in the water. This can lead to the formation of algal blooms, where the water surface becomes covered with a thick layer of algae. Decomposition: When these algae eventually die, their decomposition by bacteria consumes oxygen. The process of decomposition is accelerated when there is an abundance of organic matter, such as dead algae, in the water. Oxygen Depletion: The decomposition of organic matter consumes dissolved oxygen in the water. If the rate of oxygen consumption exceeds the rate at which oxygen is replenished through atmospheric exchange and photosynthesis, oxygen levels in the water can drop significantly. Hypoxia: Hypoxia refers to low oxygen levels in the water, which can be harmful to aquatic life. Fish and other organisms that depend on dissolved oxygen for survival may suffer or die in hypoxic conditions. The severity of hypoxia can vary, ranging from mild oxygen depletion to more severe anoxic conditions where oxygen is entirely absent.

Question 48

Define hypereutrophic and give examples of organisms present

Answer 48

* High nutrients * High turbidity * Anoxia, absence of dissolved oxygen. - No fish, only plankton.

Question 49

Explain why the 3 C’s rule exists for Lake Michigan Fish:

Answer 49

⇾ Choose fish that are primary consumers and not bottom feeders. ⇾ Clean fish for eating by removing as much fat as possible. ⇾ Cook fish on a grill or grate.

Question 50

Drinking Water Regulations

Answer 50

- Safe Drinking Water Act (EPA) - Food, Drug, and Cosmetic Act (FDA)

Question 51

- Set limits and testing requirements for contaminants in municipal tap water. - Does not apply to non-municipal well water or bottled water.

Answer 51

Safe Drinking Water Act (EPA)

Question 52

- Generally fewer testing and contaminant requirements than tap water.

Answer 52

Food, Drug, and Cosmetic Act (FDA)

Question 53

classifications of water according to Food, Drug, and Cosmetic Act (FDA)

Answer 53

Artesian: Confined aquifer Mineral/Spring: Unconfined aquifer Purified: Tapwater

Question 54

➝ In __, the __ ran aground in Alaska, causing the greatest oil spill up to that point. ➝ The __ required tankers to have a double-hull design by 2015 and increased the legal liability of oil companies for spills.

Answer 54

- 1989 - Exxon Valdez oil tanker - Oil Pollution Act of 1990

Question 55

➝ In __, the __ experienced a blowout and explosion, then leaked oil for about __. ➝ No laws were passed in response; a new executive branch agency was created to ___.

Answer 55

- 2010 - Deepwater Horizon oil rig - 3 months - oversee offshore drilling

Question 56

Impacts of oil spills on mammals

Answer 56

Penetrates their fur, causing hypothermia in cold waters.

Question 57

Impacts of oil spills on birds

Answer 57

Penetrates feathers, preventing flight and causing hypothermia.

Question 58

Impacts of oil spills on fish and plankton

Answer 58

Oil is directly toxic to them.

Question 59

Impacts of oil spills on benthos

Answer 59

If dispersants are used, oil sinks to the bottom of the sea and suffocates benthic communities.

Question 60

Impacts of oil spills on coastal ecosystems

Answer 60

Oil washes up on shore, polluting beaches and wetlands.

Question 61

Plastics are not biodegradable but will break down into smaller pieces as they are exposed to sunlight, forming tiny __.

Answer 61

microplastics

Question 62

Microplastics __ in fish and shellfish, then __ through the food chain

Answer 62

- bioaccumulate - biomagnify