Source Today’s Presentation Piping Storage, Treatment, and Distribution

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 Concrete block – Durable – No formwork – More expensive – Not entirely waterproof Cast in place concrete – Durable – Requires some skill – More expensive

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

Goals: • Effective • Inexpensive • User friendly

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