1Eco-Approach to Manage Wastewater

Dr. Roshan Raj Shrestha
Regional Technical Advisor, South Asia

14 December, 2010

WEPA Dialogue in NepalKathmadu Valley

3Kathmandu Valley Water Supply &Demand(in MLD)
350
300
250
200
150
100
500Total
Demand4Wet

Dry

SupplyHeavy Extraction of Ground Water• Groundwater abstraction rate is 6 times
higher than the limit - lowering ofgroundwater table 2.5 meters/yr.
• Arsenic, Ammonia and/or Nitrate is higher indeep aquifer from many parts of the valley• Shallow groundwater aquifer which feeds
water to dugwells, handpumps and traditionalstone spouts is also vanishing due to sealingof ground surface and destruction of rechargebasin due encroachment from infrastructuredevelopment.

No More Traditional Water ResourcesTurning Clean River in Sewer

Centralized Wastewater Treatment
Plants NOT in Function !

Who should be BLAMED

Government ?
Technology Gap ?
Poverty ?
Attitude ?
9Behavioral Issue

Looking at the Waste in to Different
Perspective

substances

urine(yellowwater)

faeces(brownwater)

treatment

hygienisation bystorage ordrying

anaerobic digestion,
drying, composting,mixing with organic
solid waste

utilisation

Source: (1)liquid or dry
fertiliser

biogas,soil
improvement

Greywater(showers, washing,etc.)

rainwater

constructedwetlands, gardening,
wastewater ponds, biol.
treatment, membranetechnology

filtration,
biol. treatment

irrigation,
groundwater
recharge ordirect reusewater supply,
groundwater
recharge

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Few Good Practices

18Response to Wastewater Management Problem• Introduced ConstructedWetland in 1997 during
PhD research;• Proved to be an effective
technology for treatmentof wastewater and greywater recycling;• Scaling up at municipality
for treatment ofmunicipal wastewater;

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Treatment of Hospital Wastewater

Graywater RECYCLING

Wastewater Treatment Plant at Gumba

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Wasteland can be converted in to Wastewater
Treatment Plant

Case Study on Community Managed System

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Community Managed Wastewater
Treatment Plant with Biogas

Biogas Digester

Decentralized waste water
management at Community

Fecal Sludge and Land fill Leachate Treatment Systemin Pokhara Municipality• Large CW system – built with several conflicts;• Concentrate more on construction rather than technical issues;• Operate without having proper training and O&M guideline

Institutional Biogas

Schechen
MonestaryHousehold biogas for urban areas

Roof Top Biogas Plant at Mr. Pandey’s House inKathmandu

Household Composting

Compost Bin

Vermi CompostingStruvite : A natural precipitation of Urine White odourless powder Magnesium Ammonium Phosphate Hexahydrate (MAP),
chemical formula MgNH4PO4 · 6 H2O
 Production process:Store urine
Add magnesium ions
Stir for some time
Filter
Let it dry

Rainwater
catchment

Rooftanks

Eco-HomeRainwater
catchment

House Without City Water Supply
Reuse & Recycle of Waste
Built in 2002 occupies 135 m2 Area
UDD
toiletDug well for
Ground water
recharge

Solarpanel

Greywater
Treatment
Plant

GardemGardenWater collection
Tank

Biosand filter
for water
treatment

Rain Water Harvesting• Rain water for 7-8 months (April to October/November)• More than 180 m3/year of rainwater harvesting potential as it
has 90.4 m2 of roof area
• Average rainy days: 69 days,

Groundwater
recharge

Underground tankDug well for groundwatercollection and recharge

Water Tank and Dugwell filled withRainwater

Water Tank
Dug well before &After rain

Treatment of Water for Drinking

Diffuser Basin
LidContainer

Water

Fine Sand
PipeCoarse Sand
GravelWater Disinfection (SODIS)Feaces & Urine Separation Dry Toilet

Faeces after
5 to 6 months

Greywater recycling

Settlement tank

V: 250 l

Feeding tank

Vertical flow Reed bed (4.8m2)

Storage tank

Greywater Treatment & Reuse

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Home Compost Bin & Vermicomposting (Eisenia foetida)WATER SUPPLY & DEMAND

Type of water use and requirement
Drinking & cooking
Dishwashing, bathing, showering, & laundry
Toilet flushing, cleaning vehicle & gardening
Total Water Demand
Reuse of Treated Greywater
Clean Water Requirement

Liters/month %
900
77500
5552503813650
1005250
38840062

Rainwater Harvesting and Water
Demand4540

39.1
36.1

35

33.1

m3

30

31.7

25
20
16

15
10.1

1050

1.1

3.5

10.1

4.3

Jan Feb Mar

1.1

Apr May Jun

Jul0
Aug Sep Oct Nov Dec

How About the Cost ?
• Total cost of the building : USD 43,000• Additional cost for this system : onlyabout 2.4 % more
• Cost has already been recovered as USD
370/year needs to be invested inprocuring water if such systems were notinstalled• In addition to the cost for buying water, it
saves significant amount of time to extract
water from the city water supply andrelieves from mental tension for nothaving sufficient water.

Established as a Demo Site

Perception fromVisitors

Need to change Behaviour of the People

Human Values Based Water Education in School

Movie on Eco house called
WATER ANGELEstablished Eco Community

Eco Village

Future Target !

Partnership with MoEJ & IGES

• Introduce cost effective technologies likeJokaso• Capacity Building & Networking• Research and Development65

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