Today’s Presentation

Piping

Storage, Treatment, and Distribution

Source

Water Sources and Collection

Developing sources of Surface Water

• Rainfall Catchments

• Ponds and Lakes

• Streams and Rivers

• Springs and Seeps

Rainfall Catchments

• Quality – Disinfection necessary

• Quantity – Seasonal

• Accessibility – In yards of users

• Reliability – Must rain; some maintenance required

• Cost – low

Ponds and Lakes

• Quality – good for large bodies of water, poor for small bodies of water

• Quantity – decrease during dry season• Accessibility – intake needed, pumping and

storage required• Reliability – good; needs knowledge of

maintenance, pumping, and treatment to operate• Cost – high because of pumping and treatment

Ponds and Lakes Diagram

Streams and Rivers

• Quality – depends on elevation. The higher, the better.

• Quantity – Seasonal

• Accessibility – Needs intake

• Reliability – maintenance required

• Cost – treatment is expensive

Streams and Rivers Diagrams

Streams and Rivers Diagrams

Streams and Rivers Diagrams

Springs and Seeps

• Quality – good; must disinfect and protect the source

• Quantity – variable for gravity-driven springs (seasonal)

• Accessibility – storage needed; gravity flow makes delivery easier

• Reliability – Good for gravity flow• Cost – Low, but will rise with the amount of

piping needed.

Springs and Seeps Diagram

Dams

Types of dams–Earth dam–Cast in place concrete–Concrete block

Dependent on:–Available resources–Size of dam–Placement of dam

Dams Pros & Cons

Earth dam– Cheep, local resources

– Must be closely watched

– Not entirely waterproof

– Require spillway

Cast in place concrete– Durable

– Requires some skill

– More expensive

Concrete block– Durable

– No formwork

– More expensive

– Not entirely waterproof

Piping

Purpose:To move water from source to village

Gravity feed

Configurations

• Buried:– Pros: Protected from elements (Sunlight, rockfall,

Landslides)

– Cons: Labor intensive and harder to maintain

• Open:– Pros: Easy to install and maintain

– Cons: Susceptible to elements

• Suspended:– Used over gorges, streams, and bad terrain

Pressure in pipe

• Large elevation drops can cause high pressure in pipes

– Certain pipes can withstand high pressure

– Build structures to reduce pressure along pipeline

Kinds of Pipes

• PVC– Used for low-pressure stretches. Deteriorate

with sunlight usually buried

• Galvanized Iron– used for high-pressure stretches and in areas

where pipes can’t be buried. Expensive

Kinds of Pipes

• HDPE– Can withstand high pressures, sunlight. Less

expensive than GI.

• Local Materials– Bamboo Trunks

• Low pressure, inexpensive

• Deteriorate rapidly, difficult to connect.

Maintenance ?

• Need inspections and upgrades

• Install valves along length of pipe.

Water Treatment

• Effective

• Inexpensive

• User friendly

Goals:

Water Treatment Options

• Centralized Treatment– Chlorination

– Slow Sand Filtration

– Solar Pasteurizers

– Murunga Seeds

• Household Treatment– Storage

– Solar Disinfection

– Biosand

Chlorination

• Most familiar treatment method• Concentrated solid is dangerous to transport and

store, dilute liquid is too bulky in large quantities• Production of Trihalomethanes• Requires regular, trained maintenance and

monitoring• Can also be done on a small, individual scale

Chlorination

• Pot Chlorination– Requires bleach powder

– Hung in well, refilled weekly

– Doesn’t meet WHO standards

– MIT is researching

• On-site production of dilute Cl by electrolysis– Requires energy! and more

training, maintenance

Slow Sand Filtration

• Easy & cheap to construct

• Easy to clean – scrape off top layer of sand

• Expensive to test effectiveness– Using cheap pass/fail

test, this will fail– More detailed results

cost 20x more

Solar Pasteurizers

• Boils Water without Fuel– Very effective at

disinfection

– Reduces deforestation

• Higher Initial Cost

• Requires Sunlight & Warm Climate– Back up burner available

• Very Low Maintenance– Runs automatically– Long lifetime

Biological Flocculants

• Seeds from Moringaceae family trees, Tuna Cactus, Potato Starch…

• Often grow indigenously• Multiple uses

– Murunga plants provide food, oil, and firewood

• Not as well known or studied

Storage

• Storing water settles out particulates and kills microorganisms

• Very Easy to set up and maintain, Very Inexpensive

• Small scale, personal responsibility• Should not use clay pots• For best results there is a long lag time

– 2 weeks storage usually optimal

Solar Disinfection• Small scale version of solar pasteurization

• Very small quantities

• Very easy, individual control

• Reliant on climate

• Time consuming

Biosand

• Biofilm forms on sand and is used to remove nutrients from the water

• Requires time for biofilm to form

• Low maintenance

• Needs more research– Successful in Nepal, problems in Sudan– Not sure why it failed in some locations

Water Treatment Summary

• There are many different methods available

• Many of these are simple and inexpensive

• Treatment can be done at almost any scale

• Unfortunately, often rely on pre-existence of some very specific features (climate, local plants, groundwater source)

Distribution in the Village

Hydraulic Ram

• Water required uphill from source• Pump water uphill along supply system• No electricity required

Example: Fleming Hydro-Ram

• A. Drive pipe• B. Poppet valve• C. Check valve• D. Compression

chamber

Water pumping process

• A. Drive pipe– Falling water enters the

drive pipe at point A until a required volume is reached.

Water pumping process

• B. Poppet Valve– Water continues

through the system until it reaches a poppet valve

– Water escapes through the waste valve until the build-up of pressure seals the opening

Water pumping process

• C. Check Valve– Water forces open the

one-way check valve because the other exit is sealed

– Water passes the check valve and begins to compress the trapped air in the vertical compression chamber

Water pumping process

• D. Compression Chamber– Water pushes against

the trapped air in the vertical compression chamber

– The trapped air acts like a piston, forcing the water back down the compression chamber

Water pumping process

• E. Delivery Pipe– With the one-way

check valve closed, the water enters the delivery pipe attached at (E) after it is forced out of the ram.

Water pumping process

• Cycle Repeats– A slight vacuum is

formed when the check valve closes

– The waste valve poppet drops open again, allowing water out of the valve.

– Approximately 60 cycles occur per minute.

Design Requirements

• Head of water supply• Size of the pump• Flow rate to the pump• Height of water

discharge

• Vertical fall• Vertical lift• Rate of ram pulsation• Length of pipe on

intake and discharge

Output Range

• 1-inch ram = 700 – 1,800 gallons/day

• 1.5-inch ram = 700 – 3,000 gallons/day

• 2-inch ram = 700 – 4,000 gallons/day

• 3-inch ram = up to 16,000 gallons/day

Efficiency

• With a ratio of 1-foot drop to 10-foot lift, the pump delivers approximately 15 – 20% of the water it uses

• Practical only if need to pump water uphill

Delivery Methods: Centralized Location

• Advantages– One installation– Easy maintenance

• Disadvantages– Overdemand due to population growth– Reliance on one source

Delivery Methods: Distributed Location

• Advantages– More than one source– Easier to upgrade

• Disadvantages– Increased installation time and money– Higher maintenance