Lecture 5: Water Resources and Pollution Flashcards
Importance of Water
➝ 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.
Distribution of Water
- 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%
Movement processes of water.
Hydrologic/Water Cycle
Liquid water is heated and converted to water vapor.
Evaporation
Evaporation from leaves
transpiration
Water vapor cools and liquefies.
condensation
Water droplets combine and fall from clouds.
Precipitation
Seeps through spaces in soil.
Infiltration
Flows downhill to a stream, then a lake or ocean.
Runoff
are underground formations of rock and sand that hold water.
Aquifers
The uppermost boundary of aquifers is called the
water table
is recharged from the ground surface directly above it.
unconfined aquifer
has an impermeable layer of clay or rock that limits recharging to a smaller area.
confined aquifer
the entire area of land where water runoff or infiltration
feeds a specific river
watershed
Withdrawal and consumption of water for agriculture, drinking, etc
water use
Amount of water diverted or removed from its source. A portion may be returned afterward.
Example:
Withdrawal
- Power plant coolant water
Water is withdrawn AND permanently removed from a source.
Example:
Consumption
- Irrigation
The three largest demands for water withdrawal include:
⇾ 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%)
the largest consumer of water worldwide, as most of
it is either taken in by plants or evaporated into the atmosphere.
Irrigation
__ occurs when the demand for water is greater than the supply. Leads to __.
water stress
- depletion of freshwater resources
Regions with water stress tend to be:
- Naturally arid
- Heavily populated
- Growing water-intensive crops and animals.
Environmental impacts of overconsumption of freshwater supplies:
⇾ Decrease in river flow.
⇾ Lowering of lake and reservoir levels.
⇾ Subsidence, or the gradual sinking of land.
Alternative water sources and reducing water consumption
water conservation
the removal of salt from ocean water, through two
possible methods: __, __
Desalination
- Distillation boils the water and collects the steam.
- Reverse osmosis passes pressurized water through a filter.
Desalination produces a lot of salt waste called __.
brine
The energy costs for desalination are __
very high
Water conservation efforts focus on __, as it is the biggest source of water consumption. Give example practices.
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.
Home water conservation centers around
high-efficiency devices. Give examples.
- 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.
uses drought-tolerant plants in the homes and yards in
arid climates.
Xeriscaping
recirculate used water from the sink or shower
into the toilet or for yard irrigation.
Graywater systems
From the Industrial Revolution until the passage of the
__, surface waters were used as __.
- Clean Water Act in 1970
- industrial dumpsites
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.
- Clean Water Act
- EPA
Causes of impaired waters
- Coliform Bacteria
- heavy metals
- Persistent Organic Pollutants (POPs)
- Oxygen Depleting Pollution
- Nutrient Pollution
Disease-causing bacteria from untreated human sewage and manure.
Coliform bacteria
Neurotoxins. Released by mining and the use of synthetic fertilizers.
Heavy metals
Synthetic chemicals that do not degrade and are prone to biomagnification and bioaccumulation.
“Forever chemicals.”
Persistent Organic Pollutants (POPs)
Biodegradable matter consumed by decomposers, who
deplete oxygen levels in the water.
Oxygen-Depleting Pollution
Nitrogen and phosphorous-rich compounds that promote algae overgrowth.
Nutrient Pollution
water pollution comes from a single, identifiable source. Examples.
Point source
➝ Factories
➝ Water treatment plants
water pollution comes runoff or infiltration from a wide area. Examples.
Nonpoint source
➝ Agricultural fields
➝ City stormwater drains
➝ Home septic systems
an increase in algae growth as fertilizer enters surface waters.
Cultural eutrophication
Trophic classifications of aquatic ecosystems
- oligotrophic
- mesotrophic
- eutrophic
- hypereutrophic
Define oligotrophic and give examples of organisms present
- low nutrients
- low turbidity
- high sunlight
Examples: - Zooplankton
- Submerged plants
- Fish
- Benthos
Define mesotrophic and give examples of organisms present
- Increasing nutrients, turbidity, and algae
- Decreasing sunlight
Examples: - More fish and zooplankton
Define eutrophic and give examples of organisms present
- High nutrients
- High turbidity
- Hypoxia, reduced dissolved oxygen
- death of submerged organisms
refers to low oxygen levels in the water, which can be harmful to aquatic life.
hypoxia
explain how the link between hypoxia and eutrophic
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.
Define hypereutrophic and give examples of organisms present
- High nutrients
- High turbidity
- Anoxia, absence of dissolved oxygen.
- No fish, only plankton.
Explain why the 3 C’s rule exists for Lake Michigan Fish:
⇾ 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.
Drinking Water Regulations
- Safe Drinking Water Act (EPA)
- Food, Drug, and Cosmetic Act (FDA)
- Set limits and testing requirements for contaminants in municipal tap water.
- Does not apply to non-municipal well water or bottled water.
Safe Drinking Water Act (EPA)
- Generally fewer testing and contaminant requirements than tap water.
Food, Drug, and Cosmetic Act (FDA)
classifications of water according to Food, Drug, and Cosmetic Act (FDA)
Artesian: Confined aquifer
Mineral/Spring: Unconfined aquifer
Purified: Tapwater
➝ 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.
- 1989
- Exxon Valdez oil tanker
- Oil Pollution Act of 1990
➝ 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 ___.
- 2010
- Deepwater Horizon oil rig
- 3 months
- oversee offshore drilling
Impacts of oil spills on mammals
Penetrates their fur, causing hypothermia in cold waters.
Impacts of oil spills on birds
Penetrates feathers, preventing flight and causing hypothermia.
Impacts of oil spills on fish and plankton
Oil is directly toxic to them.
Impacts of oil spills on benthos
If dispersants are used, oil sinks to the bottom of the sea and suffocates benthic communities.
Impacts of oil spills on coastal ecosystems
Oil washes up on shore, polluting beaches and wetlands.
Plastics are not biodegradable but will break down into smaller pieces as they are exposed to sunlight, forming tiny __.
microplastics
Microplastics __ in fish and shellfish, then __ through the food chain
- bioaccumulate
- biomagnify
