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