AICE Environmental Management - Unit 6 - Managing Water Supplies

Distribution of the Earth's water

The Earth's water can be roughly divided up into the following categories:

Salt water in oceans:

Approximately 97.5% of the Earth's water is found in oceans and seas

Oceans cover about 71% of the Earth's surface and contain vast quantities of saltwater

Surface freshwater:

Ice sheets and glaciers:

Ice sheets and glaciers store around 68.7% of the Earth's freshwater

Most of this freshwater is contained within ice caps covering Antarctica and Greenland

Lakes, rivers, swamps and marshes:

Lakes, rivers, swamps and marshes collectively hold around 0.3% of the Earth's freshwater

These surface water bodies are crucial habitats for diverse aquatic ecosystems and serve as sources of drinking water and irrigation

Most of earth LQUID freshwater is found

Groundwater ≈96%) – Stored in underground aquifers beneath the Earth's surface.

Most of earth freshwater is

Frozen in Ice & Glaciers (≈68.7%) – Locked in Antarctica, Greenland, and mountain glaciers.

Water Security

The ability to access sufficient quantities of clean water to maintain adequate standards of food and manufacturing of goods, adequate sanitation and sustainable health care

Causes of Water Insecurity

- Climate change, including changes in rainfall

- Natural disasters, including drought and flooding

- Pollution events

- Inadequate sanitation

- Population growth, changes in land usage including deforestation and urbanization

- Competing demands from agricultural, industrial, energy and domestic sectors

- Mismanagement of irrigation, including salinization

- International competition over water sources

- Inequality of availability between water-rich and water-poor regions

- Differing access to safe drinking water in urban and rural areas

Explanations of causes of water insecurity

Climate change

Changes in rainfall patterns and increasing temperatures impact water availability, leading to droughts and floods

Natural disasters

Droughts and flooding, made worse by climate change, reduce water availability and contaminate water sources - droughts reduce water availability for agriculture, industry and domestic use, while floods contaminate water sources and damage infrastructure

Pollution events

Industrial discharges, agricultural runoff and untreated sewage pollute water sources, making them unsafe for use and unsuitable for human consumption

Inadequate sanitation

Lack of proper sanitation facilities and wastewater treatment contaminates water sources, posing health risks such as the spread of waterborne diseases

Population growth and land usage

Population growth, deforestation and urbanisation increase water demand and alter the water cycle, increasing water scarcity

Competing demands from various sectors

Agriculture, industry, energy and domestic sectors compete for water resources, leading to overexploitation and rapid depletion of water sources in some regions

Mismanagement of irrigation

Inefficient irrigation practices lead to soil salinisation, reducing agricultural productivity and increasing water scarcity

International competition

Disputes over transboundary rivers and aquifers lead to conflicts among neighbouring countries over water allocation and usage right

Inequality of availability

Disparities in water availability between water-rich and water-poor regions can worsen socioeconomic inequalities and hinder development

Differing access to safe drinking water

Disparities in access to safe drinking water exist between urban and rural areas, with marginalised communities facing challenges in accessing clean and reliable water sources

Impacts of Water Insecurity

- Reduced crop yield and crop failure

- Livestock death

- Food shortages, malnutrition and famine

- Illness caused by contaminated drinking water, limited to diarrhoea and cholera

Impacts of Water Insecurity explanations

Reduced crop yield and crop failure:

Water scarcity limits irrigation for agricultural crops, resulting in reduced yields and crop failure

Lack of water leads to stunted plant growth, wilting and decreased productivity, impacting food production and livelihoods

Livestock death:

Water scarcity affects access to drinking water for livestock, leading to dehydration, reduced milk production and, ultimately, death

Limited water availability also affects the availability of fodder and grazing land, further impacting livestock health and productivity

Food shortages, malnutrition and famine:

Water insecurity contributes to food shortages and inadequate nutrition, particularly in regions heavily reliant on rain-fed agriculture

Reduced crop yields and livestock productivity lead to food scarcity, malnutrition and famine, increasing poverty and socio-economic inequalities

Illness caused by contaminated drinking water:

Waterborne diseases such as diarrhoea and cholera are prevalent in areas with inadequate access to clean drinking water

Contaminated water sources contain pathogens, leading to outbreaks of waterborne illnesses and widespread health impacts, particularly among children and vulnerable populations such as the elderly

Strategies for Managing Water Security

- Sustainable water extraction and improved supply (piped supply, aquifers and artesian wells, boreholes, gravity-fed schemes, reservoirs and dams)

- Reduction in water usage (improved irrigation techniques, growing crops less dependent on high water supply, recycling and rain water catchment)

- Education on sustainable water use

- Poverty reduction

-International agreement and water-related aid (detailed knowledge of international agreements is not required)

- Rationing

describe the 8 processes involved in the water cycle

Precipitation –water vapor condenses into tiny droplets forming clouds and eventually falls as rain/snow/sleet/hail due to gravity

Evaporation – liquid water to atmospheric water vapor

Sublimation - Solid water turning directly into vapor (common on ice caps with high power wind)

Transpiration – evaporation from biosphere -trees – send more 66,000 cubic kilometers of water vapor into the atmosphere every year (17,000 trillion gallons)

Interception – precipitation that does not reach soil (blocked by tree)

Infiltration – precipitation that soaks into ground. Part will evaporate, part will move into biosphere, most becomes groundwater.

Groundwater – flows very slowly, eventually returning to surface at springs then flows back to ocean.

Percolation – groundwater that slowly moves through the ground

Run off– all precipitation that flows over the land, including streams and fraction that temporarily infiltrates near-surface rock.

What is a watershed/drainage basin?

any area of land where percipation collects drains off an common outlet, such as into a river, bay or other body of water.

Where do most large cities get most of their water from?

Most cities obtain their water from a surface water such as sources of water from rivers, reservoirs, lakes,

explain how development impacts the water cycle.

Urbanization replaces natural landscapes with concrete, asphalt, and buildings, reducing the land's ability to absorb water.- This leads to more surface runoff, increasing the risk of flooding and reducing groundwater recharge.

Deforestation and land use changes decrease transpiration, where plants release water into the atmosphere.

Large cities with heat-absorbing surfaces increase evaporation from artificial sources like roads and buildings.

Reservoirs and Dams

Large-scale water storage disrupts natural river flow, altering evaporation rates and impacting aquatic ecosystems.

Name the three types of Aquifers

Unconfined Aquifer; level of water table and below; impermeable rock as a basement and can lose water to the surface

Confined aquifer - bound above and below by impermeable beds (shale & Clay)

Perched aquifer - occurs above the regional water table, in the vadose zone.

What causes the water level of an aquifer to drop?

1. Overuse and Excessive Withdrawal

Pumping too much groundwater for agriculture, industry, or drinking water can deplete an aquifer faster than it can naturally recharge.

This is especially common in areas where water demand exceeds natural supply.

2. Reduced Recharge

Urbanization (paving over land with concrete and asphalt) prevents water from soaking into the ground, reducing aquifer replenishment.

Deforestation decreases water infiltration because tree roots help absorb and direct water into the soil.

3. Drought and Climate Change

Prolonged droughts reduce rainfall, which limits the amount of water entering the aquifer.

Rising temperatures increase evaporation, further reducing available water for recharge.

4. Contamination and Pollution

Leaking Underground Storage Tanks (LUSTs), pesticides, and industrial waste can make aquifers unsafe to use, limiting available water.

Contaminated aquifers may need to be abandoned, forcing reliance on other water sources.

Describe the issues that are caused by overpumping groundwater near coastal areas.

Subsidence :

Salt Water Intrusion:

Leaking Underground Storage Tanks (LUSTs)

Subsidence

Subsidence: the gradual sinking of land due to excessive groundwater removal

Define water security.

the ability to access sufficient quantities of clean water to maintain adequate standards of food and manufacturing of goods, adequate sanitation and sustainable health care

Increased water use is generally correlated with what things?

1. Population Growth 👥📈

More people mean higher demand for drinking water, sanitation, and household use (showers, laundry, cooking).

2. Urbanization 🏙🚰

Expanding cities require more water for homes, businesses, industries, and public services.

Urban areas also have more impermeable surfaces, reducing natural groundwater recharge.

3. Agricultural Expansion 🌾🚜

Irrigation is the largest consumer of freshwater globally.

As food demand increases, so does the need for water-intensive crops and livestock.

4. Industrial Growth 🏭⚙

Manufacturing, energy production, and mining all require large amounts of water.

Industries like textiles, paper mills, and power plants contribute significantly to water consumption.

5. Economic Development 💰📊

Wealthier nations and communities tend to use more water per person due to modern conveniences (dishwashers, swimming pools, lawns).

Industrialized economies rely on water-intensive production

What is GRACE?

something that uses changes in the gravtaional pull to measure ground water depletion. The mission provides crucial data on water movement, ice sheet loss, and groundwater depletion.

Point Source Pollution

Definition: Pollution that comes from a single, identifiable source that directly discharges contaminants into waterways

Examples:

A factory releasing chemicals into a river.

A sewage treatment plant discharging wastewater.

An oil spill from a pipeline or tanker.

Easier to regulate because the source is known.

Nonpoint Source Pollution

Nonpoint Source Pollution 🌧🌾

Definition: Pollution that comes from multiple, diffuse sources and is carried by runoff into water bodies. poorly define and scattered

Examples: rainfall and snowmelt mover over and through the ground, picking up pollutants as they go.

Harder to control because it comes from widespread activities.

What is cultural eutrophication?

Definition: Cultural eutrophication is the accelerated aging of a water body due to excessive nutrient pollution (mainly nitrogen and phosphorus) from human activities. This leads to excessive algal growth (algal blooms), which disrupts ecosystems.

explain the oxygen sag cycle.

Clean Zone (Upstream) 🌿💦

High dissolved oxygen (DO)

Healthy aquatic life (fish, plants, etc.)

No pollution or organic waste.

Decomposition Zone (Pollution Zone) 💀⚠️

A pollution source (e.g., sewage or factory waste) introduces organic matter & bacteria.

Bacteria break down waste, consuming oxygen rapidly.

DO levels drop, stressing or killing oxygen-dependent species.

High BOD due to increased microbial activity.

Septic Zone (Lowest Oxygen Level) ☠️🔻

DO reaches its lowest point (oxygen sag).

Anaerobic bacteria dominate, producing foul-smelling gases (methane, hydrogen sulfide).

Most fish and sensitive organisms die off.

Pollution begins to dilute and disperse downstream.

Recovery Zone (DO Rises Again) 🌱💧

Organic matter is broken down and flushed away.

DO levels slowly increase as water mixes with fresh oxygen.

More tolerant fish and organisms return.

Clean Zone (Downstream) 🐟🌊

DO is restored to normal levels.

Aquatic ecosystems begin to recover.

What are 2 other names for the "dead" zone?

hypoxic zone, the low-oxygen zone, septic zone

What could trigger the oxygen sag cycle?

The oxygen sag cycle can be triggered by organic pollution, such as sewage or agricultural runoff, which contains high levels of nutrients like nitrogen and phosphorus. These nutrients promote the growth of algae, which, when they die and decompose, consume large amounts of oxygen. This depletion of oxygen creates a hypoxic (low oxygen) environment, leading to a cycle where oxygen levels drop, causing fish and other organisms to die, further worsening the oxygen deficit and creating a "sag" in oxygen levels.

Give an example of a disease that spreads through unsafe water sources.

Baby blue syndrome- caused by nitrates in drinking water

Cholera- from drinking water contaminated with feces

Guinea worm- Water with tiny water flea with larvae of guinea worms

Describe two things that toilets and poop itself can do for us.

Sanitation and Health: Proper sanitation reduces the risk of infections and promotes public health by isolating waste from drinking water sources and living environments.

Poop used as fuel-

Nutrient Recovery and Composting: Poop can be a valuable resource when managed properly. In some cases, human waste can be composted and used as fertilizer to enrich soil, making it more fertile for agriculture. This process helps recycle nutrients and supports sustainable farming practices.

Decrease sexual violence of women and increases-Women face daily threat of sexual violence and teenage girls leave school when menstruating begins

education for women-

decreases infant mortality- Diarrhea is still 2nd leading cause of childhood death of children under 5 -,Over 400,000 die a year Boost economy of LIC's- No toilets cost LIC's over 260 billion a year

Why is there a need to reinvent toilets

Water Scarcity – Traditional flush toilets use tons of water, which is unsustainable in drought-prone areas.

Infrastructure Challenges – Many regions lack sewage systems, making traditional toilets unusable.

Environmental Pollution – Untreated waste contaminates rivers, lakes, and groundwater, harming ecosystems.

Energy & Cost Issues – Waste treatment plants require high energy and maintenance costs

List the steps of a US sewage treatment plant.

Discharged into the Ocean

Deep Well Injection

Discharged back into a local river system

In PBC what happens to the biosolids?

The biosolids are tuned into fertilizer

What is the purpose of the Tertiary Treatment system?

The purpose of the tertiary treatment system in wastewater treatment is to provide an additional level of purification after primary and secondary treatment. It aims to further remove any remaining impurities, including suspended solids, nutrients (such as nitrogen and phosphorus), and pathogens, to produce water that is safe for discharge into the environment or for reuse.

What is and what are the benefits of xeriscaping?

def- the practice pf designing landscapes to reduce or eliminate the need for irrigation. (planting plants native to area)

Water Conservation: Xeriscaping reduces water consumption by selecting plants that require little water once established.

Lower Maintenance: The drought-tolerant plants used in xeriscaping generally require less upkeep than traditional landscaping.

Cost Savings: By reducing water usage and maintenance costs, xeriscaping can lead to significant savings on water bills and landscaping services.

In the US what is the single largest use of the domestic water supply?

Outside- landscaping

Inside- flushing tiolets can take 3.5-6 gallons of water

Grey water

any household wastewater with the exceptions of waste water from toilets.

Black water

Wastewater containg feces, urine, and flush wate from toliets

Reclaimed water/ recycled water

Former wastewater that is treated to remove solids and impurities and uses in sustainable landscaping irrigation, to recharge groundwater aquifers, to me commercial and industrial water needs.

Potable water

is water safe enough for drinking and food preparation.

Non-potable water

water that has not been examined, properly treated, and is not approved to be safe for cunsumtion

Indirect portable water

the reclamation and treatment of wastewater and the eventual returning of it into the water cycle upstream, of the drinking water treatment plant.

Direct potable reuse

The reclamation and treatment of wastewater for immediate potable use.

Where in the world are they using/relying on desalination?

Israel: Israel is a leader in desalination technology and has developed a large number of desalination plants, making it one of the most water-secure countries despite its arid climate.

Saudi Arabia- are some of the largest users of desalinated water. the country are located in arid regions with limited freshwater resources, and desalination is a critical component of their water supply.

Where is the largest hydroelectric dam?

Three Gorges Dam, China

actor in video

Jack Black

Dissolved Oxygen source

Sunlight and photosynthesis

BOD

sewage, manure dead stuff

Nitrate source

dead stuff, sewage, fertilizers

Low ph source

Acid rain

Fecal Coliform test source

mammal feces

Mercury sources

combustion of coal

Lead sources

lead-lined pipes in plumbing fixtures in old home, gasoline runoff

Salinity Sources

rocks and minerals from roadways

Turbidity/TDS sources

soil erosion and algae

Heat/Thermal sources

nueclear power plant

Fluoride Sources

soil and water

What is drip irrigation?

Water delivered directly to plant root

Why is drip irrigation efficient?

It minimizes waste

water governance

the system of policies, laws, and institutions that regulate water use and ensure fair and sustainable distribution

How does population growth affect water security?

It increases demand for drinking, agriculture, and industry, putting pressure on limited water resources

What are low-flow fixtures?

Devices designed to use less water while maintaining performance, reducing overall consumption in homes and buildings

ex. A low-flow showerhead

What is volumetric pricing?

A system where users pay based on the amount of water they use, motivating them to reduce unnecessary use

What are increasing block tariffs?

A pricing system where higher water usage is charged at higher rates, discouraging excessive consumption

They promote conservation by making excessive use more expensive while keeping basic use affordable

What is desalination?

The process of removing salt from seawater to produce fresh water, increasing supply in water-scarce regions

Drawback of desalination

It requires large amounts of energy and can harm marine ecosystems through brine discharge

What is wastewater recycling?

Treating used water so it can be safely reused, reducing demand for freshwater and lowering pollution

What is the IWRM

Integrated Water Resources Management (IWRM) is a holistic framework promoting the coordinated development and management of water, land, and related resources to maximize economic and social welfare without compromising ecosystem sustainability.