Unit 2 Exam (with water pollutants)

Sediment

Soil particles in bodies of water. 70% of sediment comes from human activities.

• Clear cutting, mining, and clearing land for development have all increased rates or erosion, creating sediment pollution

Issues:

• Blocks sunlight penetration, reducing productivity of algae and plants and reducing visibility of predators

• Clogs gills and prevents aquatic organisms from obtaining oxygen

Solid Waste (Trash)

Garbage thrown away by people

• Litter that reaches aquatic ecosystems (unsightly and creates intestinal blockage and choking hazards for wildlife and introduces toxic substances to the food chain

Thermal Pollution

Occurs when human activities cause a substantial change in the temperature of water

• A dramatic change in temperature can cause thermal shock, which is fatal to organisms

• Warm water holds less O₂

Noise Pollution

Sounds emitted by ships and submarines can interfere with animal communication

Especially loud sonar can negatively affect species such as whales that rely on low-frequency, long distance communication

Synthetic Compounds

Can enter water supply from industrial plant sources or from nonpoint sources when they are applied over large areas (farmland)

• Examples of synthetic compounds include pesticides and pharmaceuticals

Synthetic organic compounds can be toxic, persistent and cause genetic defects, and interfere with growth and sexual development

Oil

Petroleum products are highly toxic to many marine organisms

• Birds, mammals, and fish, as well as algae and microorganisms at the base of the aquatic food chain

Sources

• Drilling

• Oil spills from tankers

• Naturally (oil seeps)

Remediation of Oil

• Containment: booms keep the floating oil from spreading, then boats equipped with giant oil vacuums suck up as much oil as possible

• Dispersants: Chemicals break up oil on the surface, helping it dissolve before it reaches shore

• Bacteria: scientists are trying to optimize oil-degrading bacteria to break down spilled oil (bioremediation)

Heavy Metals

Neurotoxins, which affect nervous system function or development. Lead, arsenic, mercury

Lead

Found in pipes and other materials in older construction

Arsenic

Occurs naturally and through human activity such as mining and industry

Mercury

Occurs naturally and through human activity, primarily burning coal

Biological pollutants

Pathogenic microorganisms (bacteria and protists), which originate primarily from human and animal waste products

Pathogens can contaminate surface water as well as groundwater

Animal Feedlots and Manure Lagoons

Manure from concentrated animal feeding operations (CAFOs) may contain pathogens as well as hormones and antibiotics used on animals

Farmers may use manure lagoons (ponds lined with rubber) to store and decompose manure using bacteria

• Following decomposition, manure byproducts can be used as fertilizer

Ecosystem services

Includes purification of water and air, cycling of nutrients, recycling water flow, flood prevention, and reducing erosion

• Arise from normal ecosystem function

• Can be depleted or degraded

  • Materials, Cultural, Regulatory

Ecological footprint

Expresses consumption by the area of land and water needed to provide the resources a person consumes and the waste they generate

Natural capital

All of Earth’s resources and ecosystem services

Sustainability

A way of living so that the Earth’s resources can sustain us well into the future

Overshoot

Using more resources than sustainably available

Environment

Consists of all the living and nonliving things around us

Environmental science

The study of how the natural world works, how the environment affects us, and how we affect it

Oligotrophic

Healthiest type of lake

Hypoxic

Not enough oxygen

Floodplain

Areas near a river’s course that flood periodically

• Species rich

• Fertile soil

• Riparian forests

Streams

Areas where runoff converges in low-lying areas

Runoff

Water that falls from the sky or melts from snow or a glacier that flows over a land surface

Rivers

Streams merge to form

Springs

Point where groundwater from an aquifer becomes surface water naturally

Lakes and Ponds

Bodies of standing surface water

Littoral Zone

Shallow areas along edges of water, aquatic plants grow

Limnetic Zone

Upper layer of water that is shallow enough to receive sunlight and allow photosynthesis by phytoplankton

Profundal Zone

Between benthic and limnetic zones, lacks photosynthesis

Benthic Zone

Deepest zone, extends along body of water

Wetlands

Systems where the soil is saturated with water, often containing standing shallow water

Marshes

Contain standing water in forested areas

Freshwater Marsh

Contains cattails and bulrushes that grow above the water surface

Bogs

Ponds covered in thick floating mats of vegetation

Vernal Pools

Seasonal pools, form from snowmelt, dry up in summer

Dam

Any obstruction placed in a river or stream to block its flow

• Prevent floods, provide drinking water, facilitate irrigation, generate electricity

Reservoir

Artificial lakes that store water for human use

Fish Ladder

A stair-like structure that allows migrating fish to get around a dam

Infiltration

Water seeps into pores of rocks and soil

• Any water that does not evaporate, flow into waterways, or get taken up by organisms

Groundwater

Water beneath the surface that resides within pores in soil or rock

Aquifers

Porous, spongelike formations of rock or sand. Hold water underground for thousands of years at a time

Water Table

The upper border of the layer completely filled with water, directly below ground

Recharge Zone

Any area where water can infiltrate through the surface and reach an aquifer to fill it

Confined Aquifer

Bound by impermeable clay, no recharge zone (or small), slow recharge rate, old water, artesian well (no pump), less prone to pollution

Unconfined aquifer

Permeable surface on top, impermeable surface on bottom (confining bed), large recharge area, fast recharge rate, younger water, well (pump), more prone to pollution

Confining Bed

Bottom layer of unconfined aquifer, impermeable layer

Ogallala Aquifer

Largest known aquifer, under great plains, used for agriculture and irrigation, water level dropping

Cone of Depression

When a deep well over extracts H₂O causing surrounding shallow wells to go dry

Sinkhole

Caused by ground losing pressure and collapsing

Saltwater Intrusion

Wells drilled into coastal areas reduce water table and thus pressure causing saltwater to intrude into aquifer

Total per capita water use per day

The total water use per person for agriculture, industry, and households varies tremendously by country

Consumptive Water Use

Water is used and removed from an ecosystem

Nonconsumptive Water Use

Water is used and returned to an ecosystem

70

Percent of freshwater used for agriculture

20

Percent of freshwater used for industry

10

Percent of freshwater used for residential use

79

Percent of freshwater in ice caps and glaciers

20

Percent of freshwater in the ground

1

Percent of freshwater on the surface

97.5

Percent of water on earth that is saltwater

2.5

Percent of water on earth that is freshwater

Furrow

Least efficient irrigation method, a trench is flooded with water

Flood

Less efficient irrigation method where an entire field is flooded with water

Spray

More efficient irrigation where an apparatus sprays water across a field

Drip

Most efficient type of irrigation where a slow dripping hose is laid on or buried beneath soil

Hydroponic Agriculture

Very water efficient method of agriculture. The cultivation of plants in greenhouse conditions by immersing roots in a nutrient-rich solution

• Uses little or no pesticides

• Up to 95% less water usage

• Crops can be grown year round

Desalination

The removal of salt from seawater to produce freshwater

• Expensive

• Requires a lot of energy

• Salty waste - brine

Distillation

Type of desalination that evaporates water and condenses it

Reverse Osmosis

Pressure to force water through semipermeable membrane in order to remove salt

Brine

Salty waste product of desalination

Rainwater Harvesting

Process of collecting rainwater with a rain barrel

Xeriscaping

Practice of landscaping with slow-growing, drought tolerant plants to conserve water and reduce yard trimmings

Point Sources

Pollution coming from discrete locations, “you can point to it”

Nonpoint sources

Pollution from widely distributed areas, such as farms, roads, or neighborhoods

Biochemical oxygen demand (BOD)

The amount of oxygen a quantity of water uses over a period of time at specific temperatures

Eutrophication

An increase in the fertility of a body of water due to excess nutrients (called nutrient enrichment)

Cultural eutrophication

The increase in fertility in a body of water as the result of human inputs of nutrients (fertilizers/wastewater)

Dead Zones

An area with extremely low oxygen concentration and very little life, due to a high BOD

Indicator species

A special organism that scientists look for in water in order to check for certain pathogens

Oxygen sag curve

Made up of the clean zone, decomposition zone, septic zone, recovery zone, and clean zone

Coagulation, Sedimentation, Filtration, Disinfection

Steps of drinking water treatment

Septic System

A relatively small and simple sewage treatment system, made up of a septic tank and a leach field, often used for homes in rural areas

Scum

Waste in a septic tank that floats (soaps, oil)

Septage

Waste in a septic tank that is fairly clear water, middle portion, flows out into leachfield

Sludge

Waste in a septic system that is human waste

Leach field

Underground perforated pipes that allow septage to slowly drain into soil

Preliminary Treatment

Removes large particles that shut down system

• Stickers, toys, rings

• Filtered by bar screens, settling tanks, and grit chambers

Physical Separation

Primary Treatment

Allos organic material to settle

• Primary clarifier

Physical Seperation

Secondary Treatment

Microbes digest and eat any organics left

• Aeration basin (oxygenated and uses back sludge to feed bacteria)

Secondary Clarifier

Final Treatment

Kills microbes

• Chlorine gas, UV, Ozone

Sludge Treatment

Reduce volume of sludge

• Dehydrate

• Anaerobically decompose waste

Ends up as fertilizer, burned, or buried

Clean Water Act (CWA) of 1977

“see” - clean aka surface water

Set standards for contaminant levels in surface water

Funded development of sewage treatment centers

Goal: keep freshwater ecosystems clean including wetlands, lakes, rivers, streams

Safe Drinking Water Act (SDWA)

Keep water safe for human consumption

• Aquifers, lakes, rivers

Established MCL - Maximum contaminant levels for 80+ chemicals

• There isn’t a clearly defined standard for what is considered “unsafe