Drinking Water Flashcards
Explain the Water History.
1854: JOhn Snow and the Broad Street Pum
1870: Germ theory verified (Pasteur, Leewenhoek, et al.)
1908: Chick’s Law of Disinfection
1908: First U.S. cities, Jersey City and Chicago, chlorinate municipal drinking water
1914: First U.S. drinking water standards by Public Health Service (voluntary). Focus on pathogens, aesthetics.
1919: Method for controlled chlorination developed by Abel Wolman and Linn Enslow
1974: Safe Drinking Water Act enacted by EPA (biological and chemical)
What is the Problem with Water?
- In U.S. people drink `2.5 liters/day (0.66 gallons)
- it is necessary to survive
- human body is 70% water
- We cook in it, bathe in it
- Potential for chemical, biological, and physical agents to contaminate drinking water
- limited water for use
Explain Global Water Use.
- Water covers 70% of the Earth’s surface, but <1% is available for human use
- Water needed for agriculture, commercial use, industrial use, residential use, environment/ecosystems
- Across the globe, water consumption has tripled in the last 50 years
What is the minimum volume of water needed to survive?
1.3 gallons per day
How much water does the average person in the U.S. use per day?
~100 gallons (drinking, cooking, bathing, and watering their yard)
Explain the Water Use in the U.S.
- Average person uses about 100 gallons (about 400 liters) of water per day
- Average residence uses over 100,000 gallons (about 400,000 liters) during a typical year
- 30-50% is used for outdoor purposes such as watering lawns and washing cars
- 50-70% used indoors, mainly bathroom use
What are the Sources of Freshwater?
- Ground water
- Surface water
- Run-off
- Glaciers/ice
- Oceans and brackwish waters
What is Ground Water?
water stored naturally underground or that flows through rock or soil, supplying springs and wells and is less susceptible to contamination
What is Surface Water?
Water from lakes, streams, rivers, and surface springs without contamination by a variety of human, animal, and industrial sources and usually requires extensive purification
What is Run-off water?
Water originating as precipitation that runs off land into rivers, steams, lakes, and oceans, unless it evaporates first
What is Glaciers/ice?
10% of the world’s landmasses, ~70% of the world’s freshwater
What is Oceans and brackish waters?
It is costly to desalinate
What is Aquifer?
layer or section of earth or rock that contains groundwater
What is Reservoir?
artificial lakes produced by construction barriers across rivers
Explain Hydrological (Water) Cycle.
- Natural cycle by which water evaporates from oceans and other water bodies, accumulates as water vapor in clouds, and returns to oceans and other water bodies as precipitation
- Renewable water
- Nonrenewable water
What is Renewable water?
freshwater continuously replenished by the hydrological cycle for withdrawal within reasonable time limits, such as water is rivers, lakes, or resevoirs that fill from precipitation or from runoff
What is non-renewable water?
water in aquifers and other natural resevoirs not recharged by the hydrological cycle or rechached so slowly that significant withdrawal for human use causes depletion
What are some Water Availability Facts?
- although the earth’s surface (70%) ia covered largely by water, most of this water is unusable water.
- approximately 3% of all water is freshwater, of which the majority is unavailable for human use (e.g., frozen in icecaps).
- remaining 1% of readily accessible water comes from surface freshwater; sources include lakes, rivers, and shallow underground aquifers
Why Not Desalinate?
- Consumes large amounts of energy
- Requires specialized, expensive infrastructure
List some Water Facts.
- One flush of a Western toilet uses as much water as the average person in the developing world uses for a whole day’s washing, drinking, cleaning and cooking
- Water use has grown at twice the rate of population during the past century. The Middle Wast, North Africa, and South Asia are chronically short of water.
- In developing countries, as much as 90% of wastewater is discharged without treatment
Explain the Overall Basic Water Requirement.
Minimum standard to meet 4 basic needs is 0.05 m^3 to 0.1m^3 ( 13 to 26 allons) per person per day (WHO)
- drinking
- sanitation
- bathing
- cooking
In Africa women and girls spend 40 billion person-hours a year hauling water
Explain the Water Stress Index.
- Water stress: 1,000-1,700 m^3 renewable frsh water per person per year (~250,000 to 450,000 gallons) (for all uses- agricultural, industrial, commercial)
- Water Scarcity: <1,000 m^3 ( ~250,000 gallons) renewable fresh water per person per year
- Water Scarcity: lack of access to water to meet basic minimum daily needs (WHO)
- Globally, water scarcity affects in 1 in 4 people (WHO)
Explain the Consequences of Limited Water Supply.
- Higher water prices to ensure continued access to a reliable and safe supply
- Increased summer watering restrictions to manage shortages
- Seasonal loss of recreational areas like lakes and rivers when the human demand for water conflicts with environmental needs
- Expensive water treatment projects to transport and store freshwater when local demand overcomes available capacity
Name 3 types of Water Pollution.
- Chemical
- Biological
- Physical
