water

WaterWater

WaterWaterone of the most fascinating compounds on earth

necessary ingredient for all living organisms

one of the most fascinating compounds on earth

necessary ingredient for all living organisms

WaterWatercovers about 70% of the earth of the earth’s surface

340 million cubic miles of water on the planet

covers about 70% of the earth of the earth’s surface

340 million cubic miles of water on the planet

The Hydrologic CycleThe Hydrologic Cycle

Water BasicsSea water 97.2% Fresh Water 2.8%

Polar ice & glaciers 2.15%Groundwater 0.62%Lakes and Rivers 0.01%

Water BasicsSea water 97.2% Fresh Water 2.8%

Polar ice & glaciers 2.15%Groundwater 0.62%Lakes and Rivers 0.01%

Water Facts: The Numbers Game

Water Facts: The Numbers Game

97% of freshwater resources in polar regions 1,844: U.S. per capita annual withdrawal of cubic

meters of freshwater 664: World per capita annual withdrawal of cubic

meters of freshwater 500,000 tons of pollutants entering U.S. lakes and

rivers daily 1 liter of oil can contaminate up to 2 million liters of

water 67 million pounds of pesticides applied in U.S. per year 50% of world’s population affected by water shortages 30% of U.S. area under drought conditions for 2002

97% of freshwater resources in polar regions 1,844: U.S. per capita annual withdrawal of cubic

meters of freshwater 664: World per capita annual withdrawal of cubic

meters of freshwater 500,000 tons of pollutants entering U.S. lakes and

rivers daily 1 liter of oil can contaminate up to 2 million liters of

water 67 million pounds of pesticides applied in U.S. per year 50% of world’s population affected by water shortages 30% of U.S. area under drought conditions for 2002

Sources: Enviroment Canada, 2003; Public Broadcasting Station, 2002; U.S. Environmental Protection Agency, 2002.


The Three Fates of PrecipitationInfiltration

The movement of water into rocks or soil through cracks and pore spaces

RunoffWater that flows over the land

Transpiration/Evapotranspirationthe release of water vapor to the

atmosphere by plants

The Three Fates of PrecipitationInfiltration

The movement of water into rocks or soil through cracks and pore spaces

RunoffWater that flows over the land

Transpiration/Evapotranspirationthe release of water vapor to the

atmosphere by plants

The water cycleThe water cyclethe amount of water on and around this planet is fairly constant

availability of water is not as constant

the amount of water on and around this planet is fairly constant

availability of water is not as constant

90-95% of sewage and 70% of industrial wastes are dumped untreated into surface water.

Water Quality and ImpactsWater Quality and Impacts

Freshwater Biodiversity

More than 20% of freshwater fish species have become extinct, threatened or endangered.

In North America 67% of mussels, 37% freshwater fish, and 40% of amphibians are threatened or have become extinct.

Source: Living Planet Report, WWF 2002

Freshwater Species Population Index

“Water contributes much to health. Good health is the essence of development”

Water, sanitation and health : the current situation

The prevailing worldwide situation regarding water supply and

sanitation services is a source of concern in different respects.

Globally (WHO, 2000)

some 1.1

billion people are

currently without

access to improved

water supply

“Water and Sanitation are intimately linked to good health”

Globally (WHO, 2000)

some 2.4

billion don't benefit

from any form of

improved sanitation

services

Water, sanitation and health : the current situation

Access for water supply

Availability of at least 20 liters per person per day from an "improved" source within one kilometer of the user's dwelling.

Improved

Household connection

Public standpipe

Borehole

Protected dug well

Protected spring

Rainwater collection

Not Improved

unprotected well

unprotected spring

vendor provided water

tanker truck water

Definitions of access to improved water supply and improved sanitation

Improved

connection to a public sewer

connection to a septic system

pour-flush latrine

simple pit latrine

ventilated improved pit latrine

Access to sanitation

Excreta disposal systems are considered adequate if they are private and if they separate human excreta from human contact.

Not Improved

service or bucket latrines (where excreta are manually removed)

shared and public latrines

latrines with an open pit

Source: WHO and UNICEF (2003)

Diarrhea :

About 4 billion cases per year cause 2.2 million deaths, mostly among children under five.

Intestinal worms :

Infect about 10% of the population of the developing world

Trachoma :

About 6 million people are blind from trachoma.

providing improved water supply could reduce the infection rate by 25%.

Schistosomiasis :

About 200 million people are infected.

Improved water supply and sanitation could reduce infection rate by 77%.

Source: Global water supply and Sanitation Assessment. 2000 Report

Most frequent diseases due to poor water supply and sanitation

WatershedWatershed


Infiltration capacity of the soil is controlled by:Intensity and duration of rainfallSoil saturationSoil textureSlope of the landNature of the vegetative cover

Infiltration capacity of the soil is controlled by:Intensity and duration of rainfallSoil saturationSoil textureSlope of the landNature of the vegetative cover

The water cycleThe water cycleif the oceans were not recharged, their water level would decrease over 40 inches per year

if the oceans were not recharged, their water level would decrease over 40 inches per year

Main Sources of WaterMain Sources of Water

Surface WaterLakes, rivers, reservoirs

Ground WaterIn the Earth, flows through fractures

and pores

Surface WaterLakes, rivers, reservoirs

Ground WaterIn the Earth, flows through fractures

and pores

What is Groundwater?What is Groundwater?

Water found in the pores and fractures of soil and bedrock

Largest reservoir of fresh water

Tends to be less polluted than surface water

Water found in the pores and fractures of soil and bedrock

Largest reservoir of fresh water

Tends to be less polluted than surface water

Groundwater Movement & Storage

Groundwater Movement & Storage

Aquifer - A zone of Earth material capable of supplying groundwater at a useful rate from a well

Aquifer - A zone of Earth material capable of supplying groundwater at a useful rate from a well

Getting Groundwater Out of the Ground


Extraction Methods“Natural” Methods

Springs, Hot Springs, & Geysers

Extraction Methods“Natural” Methods

Springs, Hot Springs, & Geysers



Extraction Methods (continued)Man-made Methods

Wells

Extraction Methods (continued)Man-made Methods

Wells



Problems with groundwater removalNon-renewable resourceSubsidenceContamination

Problems with groundwater removalNon-renewable resourceSubsidenceContamination

Water and FoodWater and Food

~85% of world consumptive water use to produce food

~85% of world consumptive water use to produce food

http://www.irrigation.org/ag_brochure1.htm

Consumptive freshwater use in the United States:

U.S. Water FactsU.S. Water FactsSource of freshwater withdrawals in

the United States (1990)

90%

10%

Surface Water 259 billion gallons/dayGround Water 79 billion gallons/day

Source: U.S. Geological Survey, 2003

U.S. Water FactsU.S. Water Facts

Freshwater withdrawals in the U.S. in 1995, by category of water use

(billion gallons of water used per day)Industry/Mining 23.37%

Commercial 2.91%

Irrigation 13439%

Domestic 3.41%

Livestock 5.52%

Power Generation 13238%

Public Supply 40.212%

Source: U.S. Geological Survey, 2003

Designing with WaterDesigning with Water

Source to SinkSource to Sink

PossibilitiesPossibilities

Rainwater HarvestingRainwater Harvesting

= Collect rainwater from building roofs to use for other purposes instead of losing as runoff

Been around for thousands of years

Currently used all over the world, from

Haiti to the Berkeley hills

= Collect rainwater from building roofs to use for other purposes instead of losing as runoff

Been around for thousands of years

Currently used all over the world, from

Haiti to the Berkeley hills

Low Cost RoofwaterLow Cost Roofwater

A house with a 1,000 sq. ft. roof could yield 600 gallons of rainwater from a one inch rainfall A = (catchment area of building)

R = (inches of rain)G = (total amount of collected rainwater)

(A) x (R) x (600 gallons) / 1000 = (G)

A house with a 1,000 sq. ft. roof could yield 600 gallons of rainwater from a one inch rainfall A = (catchment area of building)

R = (inches of rain)G = (total amount of collected rainwater)

(A) x (R) x (600 gallons) / 1000 = (G)

Domestic UsesDomestic UsesIn the US each person uses approximately 150 gallons of water per day

bath - 3-40 gallonsshower - 5 gallons per minute

In the US each person uses approximately 150 gallons of water per day

bath - 3-40 gallonsshower - 5 gallons per minute

Water ConservationWater Conservation

= Technologies or ideas that can be used to reduce the amount of water consumed per person

Household level Residential use ~75% of urban demand 60% of residential use is indoors

Source: Environmental Protection Agency, 2003.

= Technologies or ideas that can be used to reduce the amount of water consumed per person

Household level Residential use ~75% of urban demand 60% of residential use is indoors

Source: Environmental Protection Agency, 2003.

Efficient ToiletsEfficient Toilets 40% of household water used in toilets Conventional toilets use 3.5 – 5 gallons per flush Alternatives

Toilet displacement devices Low flow: 1.6 gpf Cascading toilets: use water from sink to flush Composting toilets: little to no water used

Energy Policy Act of 1992 - new home use toilets must operate on 1.6 gallons per flush or less

40% of household water used in toilets Conventional toilets use 3.5 – 5 gallons per flush Alternatives

Toilet displacement devices Low flow: 1.6 gpf Cascading toilets: use water from sink to flush Composting toilets: little to no water used

Energy Policy Act of 1992 - new home use toilets must operate on 1.6 gallons per flush or less

Sources: Alexander, 2003; EPA, 2003; Oasis Design, 2003. Sources: Alexander, 2003; EPA, 2003; Oasis Design, 2003.

Composting ToiletsComposting Toilets

Phoenix, Inc.

ShowersShowers 30% of household water used in showers

Water consumption Standard: 4.5 gpm Low-flow: 2.5 gpm Ultra low-flow: 1.5 gpm

Low-flow showerheads cost ~$5 and can save 20,000 gallons/year in a 4 person household

30% of household water used in showers

Water consumption Standard: 4.5 gpm Low-flow: 2.5 gpm Ultra low-flow: 1.5 gpm

Low-flow showerheads cost ~$5 and can save 20,000 gallons/year in a 4 person household

Source: EPA, 2003.Source: EPA, 2003.

Other household water uses

Other household water uses

Other appliances with low-flow alternativesFaucets = 5% of total indoor

household useWashing machines = 20% of totalDish washers = up to 5% of total

Save water and energy required to heat “extra” water

Other appliances with low-flow alternativesFaucets = 5% of total indoor

household useWashing machines = 20% of totalDish washers = up to 5% of total

Save water and energy required to heat “extra” water

Source: EPA, 2003.Source: EPA, 2003.

What is Greywater?What is Greywater?= Water that has been used in the = Water that has been used in the

home, except water from toilets home, except water from toilets (blackwater). (blackwater).

Dish, shower, sink and laundry Dish, shower, sink and laundry water comprise 50-80% of water comprise 50-80% of residential wastewaterresidential wastewater

= Water that has been used in the = Water that has been used in the home, except water from toilets home, except water from toilets (blackwater). (blackwater).

Dish, shower, sink and laundry Dish, shower, sink and laundry water comprise 50-80% of water comprise 50-80% of residential wastewaterresidential wastewater

Source: USEPA 1992Source: USEPA 1992

Total Total Greywater=Greywater=

59%59%

Source: Home Energy Magazine Online, July/August 1995. Source: Home Energy Magazine Online, July/August 1995.

Integrated SolutionsIntegrated Solutions

Filtration

Rapid sand filters

Do not remove fecal pathogens

Slow sand filters

More effective in removing particulates and microbial contaminants and are simpler to operate.

Low cost and Low maintenance

Carbon filters for household use

Fitted to municipal connection in the kitchen

Source: Ashok Gadgil, Drinking water in the developing countries, Ann.. Rev. Energy Environ. 1998

Water treatment

Chlorination

Used world wide

Cheap disinfectant

Residual free chlorine

In many smaller communities in developing countries various solid and liquid chemical forms of chlorine is used since they are safer to transport and handle than chlorine gas.

Disadvantages:

Large systems require skilled technical operators, repair and maintenance .

Disinfection by-products (DBPs)


Chlorination

Used world wide

Cheap disinfectant

Residual free chlorine

In many smaller communities in developing countries various solid and liquid chemical forms of chlorine is used since they are safer to transport and handle than chlorine gas.

Disadvantages:

Large systems require skilled technical operators, repair and maintenance .

Disinfection by-products (DBPs)


Water treatment

UV disinfection

Ultraviolet light in the wavelength 240 to 280 nm has been known to be of germicidal

Disinfection imparts no taste or odor Presents no risks from overdosing or carcinogenic by-products Scaling down plant size does not increase cost ($ 0.02 / m3 of water treated)

Disadvantages:

No residual disinfection and better to be used at point-of-use system Biological films and chemical fouling. (when lamp is off during hours of disuse) Makes it expensive and complex puts it beyond rural communities. Can only be used with pressurized water source like tap water and not so useful for people

collecting water from surface water or hand pumps. Need of electricity


UV disinfection

Ultraviolet light in the wavelength 240 to 280 nm has been known to be of germicidal

Disinfection imparts no taste or odor Presents no risks from overdosing or carcinogenic by-products Scaling down plant size does not increase cost ($ 0.02 / m3 of water treated)

Disadvantages:

No residual disinfection and better to be used at point-of-use system Biological films and chemical fouling. (when lamp is off during hours of disuse) Makes it expensive and complex puts it beyond rural communities. Can only be used with pressurized water source like tap water and not so useful for people

collecting water from surface water or hand pumps. Need of electricity


Conventional coaxial UV treatment unit

Water treatment

Pasteurization

Boiling the oldest form of obtaining water free of biological contaminants.

In many developing countries residents routinely boil their drinking water - Half the population in China boil the water, mostly over biomass-fueled stoves.

Water does not need to be boiled to disinfectHolding at high enough temperature ( 6 minutes at 70 C is sufficient) is sufficient to pasteurize the water to make it safe for drinking.

WHO recommends bringing the water to a vigorous boil for one minute at sea level and 1 degree more for every 100 m altitude gain.

Sustainable? No…… most people do not have that much fuel for cooking the meals even. - Average family will require 12 kg of wood for boiling the water to boil 35 liters of water.

It is economically unrealistic and environmentally unsustainable to recommend boiling daily drinking water to the poor in the developing world.


Pasteurization

Boiling the oldest form of obtaining water free of biological contaminants.

In many developing countries residents routinely boil their drinking water - Half the population in China boil the water, mostly over biomass-fueled stoves.

Water does not need to be boiled to disinfectHolding at high enough temperature ( 6 minutes at 70 C is sufficient) is sufficient to pasteurize the water to make it safe for drinking.

WHO recommends bringing the water to a vigorous boil for one minute at sea level and 1 degree more for every 100 m altitude gain.

Sustainable? No…… most people do not have that much fuel for cooking the meals even. - Average family will require 12 kg of wood for boiling the water to boil 35 liters of water.

It is economically unrealistic and environmentally unsustainable to recommend boiling daily drinking water to the poor in the developing world.


Water treatment

Solar water disinfection (SODIS)

It is a simple water treatment method using solar UV-A radiation and temperature to inactivate pathogens causing diarrhea.

SODIS is ideal to treat small quantities of water.

Contaminated water is filled into transparent plastic bottlesPET (Polyethylene Terephtalate) are preferred because they contain less UV-stabilisators than PVC

Exposed to full sunlight for six hours Radiation in the spectrum of UV-A (wavelength 320-400nm)

Increased water temperature.If the water temperatures raises above 50°C, the disinfection process is three times faster.

SODIS is more efficient in water containing high levels of oxygen.

Solar water disinfection (SODIS)

It is a simple water treatment method using solar UV-A radiation and temperature to inactivate pathogens causing diarrhea.

SODIS is ideal to treat small quantities of water.

Contaminated water is filled into transparent plastic bottlesPET (Polyethylene Terephtalate) are preferred because they contain less UV-stabilisators than PVC

Exposed to full sunlight for six hours Radiation in the spectrum of UV-A (wavelength 320-400nm)

Increased water temperature.If the water temperatures raises above 50°C, the disinfection process is three times faster.

SODIS is more efficient in water containing high levels of oxygen.

Water treatment

Source and graphics: SANDEC (Water & Sanitation in Developing Countries) at EAWAG , Switzerland.

Solar water disinfection (SODIS)Solar water disinfection (SODIS)

Water treatment


SODIS requires sun radiation and temperature:

Exposed to the sun for 6 hours if the sky is bright or up to 50% cloudy

Exposed to the sun for 2 consecutive days if the sky is 100% cloudy

If a water temperature of at least 50°C is reached, an exposure time of 1 hour is sufficient

The most favorable region for SODIS lies between latitudes 15°N/ S and 35°N/ S.

SODIS requires relatively clear water with a turbidity less than 30 NTU.

Water Turbidity Test: Read the letters of the SODIS logo through the water.

SODIS requires sun radiation and temperature:

Exposed to the sun for 6 hours if the sky is bright or up to 50% cloudy

Exposed to the sun for 2 consecutive days if the sky is 100% cloudy

If a water temperature of at least 50°C is reached, an exposure time of 1 hour is sufficient

The most favorable region for SODIS lies between latitudes 15°N/ S and 35°N/ S.

SODIS requires relatively clear water with a turbidity less than 30 NTU.

Water Turbidity Test: Read the letters of the SODIS logo through the water.


Water treatment

CCS (Ceramic Colloidal Silver) filter

An new alternative to conventional ceramic candlefilters is the CCS system.

It has a vessel-shaped filtering element which has a bigger capacity and is easier to produce locally and is less risky in use and maintenance.

Remove turbidity and 98- 100% of the harmful bacteria that cause diarrhea, cholera and other waterborne diseases.

Maintenance consist of cleaning with a brush and changing the US$ 3 filter element every 2 years.

If filled up twice a day the filter produces enough for a family of 6.

CCS (Ceramic Colloidal Silver) filter

An new alternative to conventional ceramic candlefilters is the CCS system.

It has a vessel-shaped filtering element which has a bigger capacity and is easier to produce locally and is less risky in use and maintenance.

Remove turbidity and 98- 100% of the harmful bacteria that cause diarrhea, cholera and other waterborne diseases.

Maintenance consist of cleaning with a brush and changing the US$ 3 filter element every 2 years.

If filled up twice a day the filter produces enough for a family of 6.

Source: http://www.practicafoundation.nl

Water treatment

The Urban Watershed and Low Impact

Design

Materials courtesy of the SFPUC

Urban Permaculture Urban Permaculture InstituteInstitute

W h a t i s L o w I m p a c t D e s i g n ?

LID is a stormwater management approach that aims to re-create and mimic these pre-development hydrologic processes by increasing retention, detention, infiltration, and treatment of stormwater runoff at its source.

LID is a distinct management strategy that emphasizes on-site source control and multi-functional design, rather than conventional pipes and gutters.

Whereas BMPs are the individual, discrete water quality controls, LID is a comprehensive, watershed- or catchment-based approach.

These decentralized, smallscale stormwater controls allow greater adaptability to changing environmental and economic conditions than centralized systems.

Eco Roofs Green roofs, or eco-roofs, are roofs that are entirely

or partially covered with vegetation and soils. Eco-roofs have been popular in Europe for decades

and have grown in popularity in the U.S. Recently as they provide multiple environmental benefits.

Eco-roofs improve water quality by filtering contaminants as the runoff flows through the growing medium or through direct plant uptake.

Studies have shown reduced concentrations of suspended solids, copper, zinc, and PAHs (polycyclic aromatic hydrocarbons) from eco-roof runoff.

D e s i g n D e t a i l s An intensive eco-roof may consist of shrubs and small trees

planted in deep soil (more than 6 inches) arranged with walking paths and seating areas and often provide access for people.

In contrast, an extensive eco-roof includes shallow layers (less than 6 inches) of low-growing vegetation and is more appropriate for roofs with structural limitations.

Both categories of eco-roofs include engineered soils as a growing medium, subsurface drainage piping, and a waterproof membrane to protect the roof structure.

Downspout Disconnect

Downspout disconnection, also called roof drain diversion, involves diverting rooftop drainage directly into infiltration, detention, or storage facilities instead of into the sewer.

Rainwater can be harvested from most types of rooftops. In areas where site conditions allow infiltration, roof

drainage can be conveyed to drainless bioretention planters, dry wells, or can be simply dispersed onto a rain garden, lawn, or landscaped area

On sites that are not amenable to infi ltration, roof drains can be routed into cisterns which are available in a range of materials, sizes, and models.

Rain Gardens

Rain gardens are stormwater facilities integrated into depressed landscape areas.

They are designed to capture and infiltrate stormwater runoff. Rain gardens include water-tolerant plants in permeable soils

with high organic contents that absorb stormwater and transpire it back into the atmosphere.

Rain gardens are a subset of bioretention planters except that they do not typically include engineered soils or an under-drain connection.

Plant species can be selected to stack functions and provide yields.

Typical Rain Garden

Bioretention Planters Bioretention is the use of plants, engineered soils, and a rock

sub-base to slow, store, and remove pollutants from stormwater runoff.

Bioretention planters improve stormwater quality, reduce overall volumes, and delay and reduce stormwater runoff peak flows.

Bioretention planters can vary in size from small, vegetated swales to multi-acre parks; however, there are limits to the size of the drainage area that can be handled.

System designs can be adapted to a variety of physical conditions including parking lots, roadway median strips and right-of-ways, parks, residential yards, and other landscaped areas and can also be included in the retrofits of existing sites.

Street-side bioretention planterbased on Portland’s Green

Streets

Detention Basins Detention basins are temporary holding areas for

stormwater that store peak flows and slowly release them, lessening the demand on treatment facilities during storm events and preventing flooding.

Generally, detention basins are designed to fi ll and empty within 24 to 48 hours of a storm event and therefore could reduce peak flows and combined sewer overflows.

If designed with vegetation, basins can also create habitat and clean the air whereas underground basins do not.

Surface detention basins require relatively flat slopes.

water

Documents

water cycle

movement of water

water tanker truck water

water shortages

water facts

water quality

liters of water

water level