WEPA Nepal Dialogue
Site Visit Report
13and 15 December, 2010, Kathmandu, Nepal
I. Summary of the Site Visit on 13th December
Sundarijal Area
NHPC-IDBC officeABC

RouteHotelHimalaya

The purpose of site visit was to gain knowledge of the Japanese participants of the Dialogue about water
resource utilisation, state of water environment and future action plan of the Bagmati River, which is
the major river system of Kathmandu Valley. The tour started from the upstream of the Bagmati River
where a dual purpose dam and a drinking water treatment plant were observed. Then we descended
downstream of the Bagmati River where increasing human settlement and gradual deterioration of riverwater quality were apparent. Finally the tour concluded at the office of High Powered Committee forIntegrated Development of the Bagmati Civilization (HPC-IDBC), Nepal Government, Guheshwori, where
the officials introduced us to the Bagmati Action Plan (2009-2014) and a wastewater treatment plant
being operated by the office.

Bagmati River in the upstream at Sundarijal

Bagmati River in the downstream city area

1) Sundarijal
Sundarijal Sub-catchment (15 Km2) is located in Sivapuri National Park at the north of Kathmandu Valley.
The Bagmati River originates at an elevation of 2732m in Shivapuri National Park and then flows alongSundarijal Sub-catchment before entering into the plain valley area of the city. The river flowing along
the sub-catchment has been used for hydroelectricity generation, drinking water supply to people livingin Kathmandu City and irrigation in nearby fields. We visited two main interest points, namely, dualpurpose Sundarijal Dam and Sundarijal Water Treatment Plant.

34121) Sundarijal Dam (1620m); 2) Water Channel; 3) Hydropower Station (1394m); 4)Raw water storage tank of WTP(1389m)

567895) Aeration by natural fountain; 6) Coagulation, flocculation and sedimentation tank; 7) Sand filtration tank;8)Finally treated water after chlorine disinfection; 9) Water supply to nearby households and city1.1) Sundarijal Dam
Sundarijal Dam (elevation: 1620m) was constructed in 1934 for the production of hydroelectricity by
Sundarijal Hydropower Station (elevation: 1394m) which has an installed capacity of 0.64 Megawatts(MW) of electricity. In 2006, the average water discharge of the dam was 165 l/sec. The station
management and distribution of electricity is carried out by Nepal Electricity Authority (NEA). Afterelectricity generation, the water coming through the dam is treated for use as a drinking water supply in
Kathmandu City.
1.2) Sundarijal Water Treatment Plant (WTP)
Sundarijal WTP was constructed in 1966 under Indian Government assistance. It is located just below
Sundarijal Hydropower Station (elevation: 1389m) and it uses raw water coming out after theproduction of electricity. The WTP is currently managed by Kathmandu Upatyaka [valley] Khanepani[drinking water] Limited (KUKL). Initially, there were only two storage structures having capacity tosupply about 30 MLD, which is mainly used by WTP. Recently a new storage structure of a capacity tosupply 30 MLD has been constructed with Japanese Government assistance which is used to supply raw
water to another water treatment plant located at Mahankal in the city area. During 1980s time theWTP used to be the main source water supply to Kathmandu City, however now it can hardly fulfil onefifth of the current water demand of Kathmandu City which exceeds 225 MLD.
The WTP has adopted conventional purification processes and it is operated on a gravitational flowsystem. The treatment processes are raw water storage, aeration, coagulation-flocculationsedimentation, sand filtration, and disinfection by chlorine. The majority of the treated water is thendiverted to a distribution point at Mahankal in the city, where the treated water is periodicallymonitored for water quality with reference to WHO drinking water quality guidelines. Drinking waterfor households in areas located in between the WTP and Mahankal distribution point is directly supplied
through the main line. Old infrastructure and lack of regular maintenance are the main problems formaintaining efficient treatment while insufficient quantity of available water in the dry season andleakage along transmission line are other problems for maintaining regular supply.

In front of HPC-IDBC office

Presentation about Bagmati Action Plan (BAP)

2) High Powered Committee for Integrated Development of the Bagmati Civilization (HPC-IDBC), Nepal
Government, Guheshwori, Kathmandu, Nepal
Mr.Ram Chandra Devkota introduced the Bagmati Action Plan (BAP) being implemented by HPC-IDBC
for the conservation of Bagmati River System. Mr.Devkota highlighted the cultural and religious
importance of the Bagmati River environment. Increasing pollution, illegal river side encroachment andreduced discharges are identified as key issues of the Bagmati River. BAP has adopted a comprehensive
framework of planning with a vision of clean, green and healthy river system that is full of life andvalued by all. BAP has identified five priority zones in order to achieve its vision.
Zone 1

Zone 2Naturalconservation
zone
Rural zone

Zone 3Peri-urban zone

Zone 4

Urban zone

Zone 5

Downstreamzone

To maintain and enhance theupstream river ecosystem
To restore the river ecosystemthrough sustainable development
approach
To restore the river ecosystemthrough effective management ofurban growth
To improve water quality andregenerate heritage linked with rivers
To enhance self-purifying capacity

Source: Bagmati Action Plan (2009-2014)

Currently BAP is implementing various activities such as improvement of the river course throughcommunity participation, procurement of land for the creation of green belt on both sides of river,construction of sewer line, operation of WWTP, and conservation of cultural heritage sites. The budget
provided by the government for the implementation of BAP is insufficient and funding opportunities arebeing discussed with donor agencies.
After an introductory presentation of BAP, Mr. Devkota showed WWTP, located just behind the HPCIDBC office. The WWTP was designed in 1996 and it came into operation in 2001. The WWTP design isbased on extended aeration type consisting of deep oxidation ditch of carrousel type. The major units
and operational components of WWTP can be seen in the following table:Units
1) Primary unit

Operation
Mechanical bar screening, Sump well,
Mechanical grit chamber

2) Biological unit Capacity: 10400 m3; Total oxidation[2units demand: 355kg/hr; MLSS: 3500mg/l;
oxidation ditch Total power required: 375 KWh(80m×20m)]

3) Secondary
Capacity: 1650 m3 eachClarifier[2 units of 27 mdiameter]
4) Sludge
2 drying beds of 27m×74m; drying
treatment
period: 2-3 weeks

211) Secondary clarifier; 2) Sludge treatment

5) Final effluent
and effluentbypass

Final effluent

Effluent bypass canal

The WWTP has a design service area of 537 hectares, population of 198,000 and design wastewater flowof 0.190 m3/s. The design parameters of water quality for influent and effluent are 270 mg/l and 25 mg/l
for BOD5, 1150mg/l and 250 mg/l for COD; and 216 mg/l and 100 mg/l for SS, respectively. The WWTP
also has a water quality laboratory for monitoring performance of different treatment processes. To
avoid excess flow of untreated water during the monsoon into the Bagmati River, just in front of holyPashupatinath Temple, the WWTP effluents are diverted to outside of the temple boundary through abypass tunnel. The major issues of WWTP management are: WWTP is already running over its designcapacity; WWTP usually receives high load of suspended solids which often results into ineffective
treatment of wastewater; frequent power cuts stops WWTP operation; and high operation cost. Thereis a plan to upgrade the capacity of WWTP by constructing an additional operation unit parallel to thecurrent one and also the construction of sewer lines in the upstream areas to divert all wastewater into
the WWTP.

II. Summary of the Site Visit on 15th December

NABCDRouteConstructed Wetland
WWTP

Hotel Himalaya

Community Water
Supply, Patan

Lagoon type WWTP
(partly functional)

The purpose of second day site visit was to gather information about practices of community level water supply
and wastewater management practices. First, the team visited the ancient city of Patan to observe traditional
water management practices such as a dug well, water sprouts, and water conservation ponds. People in this areaused to depend on dug wells and water sprouts to meet their daily water supply needs for hundreds of years. On
the other hand the water conservation ponds distributed across this area used to serve as storage of excess
rainwater flow, increase aesthetic environment, and also supply water for non-drinking purposes during dryperiods. Lack of proper management has resulted into their degradation and loss of their beneficial services to thecommunity. Recently, the conservation ponds have been identified as potential sites for the recharge of depleted
groundwater table in the area.

Dug Well in PatanTraditional Water Conservation Pond in
Traditional Water Sprout in Patan
Patan
After visiting the Patan area we headed east towards Bhaktapur City, where we observed local scale domestic
wastewater treatment plant based on constructed wetland. We concluded our tour at a partially functioning
wastewater treatment plant operated by the government.
1) Community Water Supply (Gaj Laxmi Drinking Water Management Committee, Chyasal, Patan)
The surrounding area of this community used to depend on water sprouts for its daily water supply needs formany years. About 7 years ago the water sprout dried up during the dry season of the year and concurrently, thecity run water supply was also not sufficient and very irregular. As a result the community faced severe water
shortages during the dry season. The Urban Environment Management Society (UEMS), UNHABITAT (an INGO)
and ENPHO (a local NGO) approached the community to assess the possibility of constructing a dug well tosupplement water supply during the dry season. Later local government provided funds to construct the dug well.
After completion of the dug well construction, there was sufficient water but water quality was not good enoughfor domestic uses, especially as there was high iron content and an odour problem. So the community again
approached UEMS, UNHABITAT and ENPHO for the construction of a bio sand filtration system As a result

UNHABITAT provided the main financial and technical support and other organisations provided technical support.
Locals mainly volunteered for necessary labour service and the construction was completed in April 2007, threemonths prior to the estimated completion time.

123

Dried Water Sprouts51) Dug Well (+ rainwater storage)642) Air contacting unit;
3) Sedimentation tank10711894) Overhead storey for biosand filter unit and storage offiltered water; 5) inside bio
sand filtration unit

Layers of bio-sandfilter unit 6)
unfiltered water; 7)fine sand; 8) coarsesand; 9) Gravel10) Taps for receiving
filtered water; 11) jerrycans (20 liters) for
distribution of water

Experimental unit testing
for removal ofcontaminants

The filtration system consisted of a dug well, which also stores rainwater harvested from roof tops, as a main
source of raw water. The raw water is pumped to a sedimentation tank (5000 liters capacity), but before entering
the tank, the water has contact with air to remove the odour. Iron particles in the water are then allowed to settle
overnight, and after that the water is pumped into the bio-sand filtration unit (3 units with 1000 liters capacityeach) which has the capacity to filter 300 liters per hour. Each bio sand filtration unit consists of fine sand, coarse
sand and gravel in layers. The filtered water is then stored in a 3000 liters tank, which is distributed through taps
by filling 20 liter jerry cans. Before distribution, chlorine is added to the water for disinfection because the water ismainly used for drinking and cooking purposes.
Every jerry can containing 20 liters of filtered water is sold for NRS 3 per can to the local community and NRS 5 per
can to people outside of the local community. The system can produce 6000 liters of water per day and serves
about 300 households. The demand for water usually goes up during the dry season when other alternative water
sources are not sufficient. Income from selling water is used for regular maintenance and providing salaries for thestaff. Regular management tasks include cleaning of the sand filter (especially removal of the iron layer on the top
once every 3 to 7 days), cleaning of jerry cans, testing of filtered water quality once in a month using test kits, andbookkeeping of daily transactions. The main problems are high iron content that reduces filtration rate to 100liter/hour and low demand during wet season when alternative water sources are available. During the highdemand period, cleaning of the filter is often conducted every day to enhance the filtration rate.

2) Sunga Wastewater Treatment Plant (WWTP), Madhyapur Thimi, Bhaktapur
Sunga WWTP is the first community based WWTP in Nepal that uses constructed wetland for the treatment ofwastewater. It was introduced by an organisation called the Environment and Public Health Organization (ENPHO)in October 2005. The constructed wetland is a biological wastewater treatment technology designed to mimic
processes found in natural ecosystems where wetland plants and their associated micro-organisms remove
pollutants from wastewater. There are about 13 constructed wetland treatment systems at the community level(or individual household level) that have been constructed by ENPHO with the help of other organisations.

Final effluent
3collection tank (6m )Vertical flow reed bed receiving
effluent from feeding tank

Vertical flow reed
2beds(150m )Sludge Drying Bed
2(55 m )Horizontal flow2
reed beds(150m )Feedingtank

Anaerobic baffled
3reactor (42m )Biogas production
plant
Screen and grit chamber receiving
wastewater influent

Horizontal flow reed
bed receiving effluent
from anaerobic baffled
reactor

The WWTP was designed to provide service to 200 households but currently only 84 households are connected to3
the WWTP. It can treat 50 m of wastewater per day with influent quality of 900 mg/l. It has an anaerobic baffled
3reactor (ABR) of 42 m which is also connected to a biogas production plant. The effluent coming out of ABR is2
2
send to horizontal flow reed bed (HRB) (150 m ) followed by vertical flow reed bed (VRB) (150 m ) for secondary
treatment. The final effluent coming out of VRB is send into a collection tank after which the effluent is sent to thenatural environment. The WWTP can remove about 80% of BOD5 and COD, 90% of TSS, 60% of TP, 75% of2ammonia and 99% of faecal coliform. Excess sludge is collected in sludge drying bed (55 m ).
Operation, maintenance and management of the WWTP is completely done by 17 members of the management
committee representing local leaders, community based organisations, the community, municipality and localschools. Madhyapur Thimi Municipality initially provided the required land for construction along with financialassistance (NRS 50,000 annually for operation and maintenance of WWTP including remuneration (NRS3000/month)) and equipment for the caretaker. So far community members are using the services free of charge.
ENPHO is mainly providing technical support to the community whenever requested.

3) Sallaghari WWTP, Sallaghari, Bhaktapur
This treatment plant used to receive wastewater from Bhaktapur Urban area. It was constructed in 1983 with GTZ
support. Its treatment capacity was 2.0 MLD and it was originally designed as an aerated lagoon system using
diffused aeration equipment. The treatment plant is based on simple lagoon systems, where wastewater is treatedthrough natural processes such as sedimentation and biological degradation in a series of large lagoons. TheWWTP stopped its full scale operation in 1991 after a problem occurred in its pumping and aeration equipment.
Since then the WWTP is partially operating without any aeration. Currently, aquatic plants growing inside thelagoon ponds are harvested by locals to feed their livestock.

Non-functioning
Pump

Lagoon pond for wastewater
treatment

Locals harvesting fodderfrom lagoon pond forlivestock feeding