This site is 670.00 meter high from mean sea level and 120.00
meter low from normal operating level of Phewa Lake. The civil
construction work of landfill site was completed in June 2003.
(Aasad 2060 BS) The inauguration date of this site was in 24th
magh 2061. The area of this landfill sit is as following
Area Landfill Area 80.00 Ropanni ~ 4.068 ha
Treatment AREA 30.00 Ropani
Buffer zone internal Road
And other infrastructure 75.00 Ropani
Composting area 15.00 Ropani
Total 200.00 ~10.00 ha.
Construction Cost
Access road construction Rs. 74231314/-(Donation)
Treatment plant construction Rs. 40085775/-(Loan)
Landfill Area construction Rs. 34852154/-(loan)
Total Rs. 14, 91, 69,283/-
Equipment cost Rs. 4, 92, 16,926/-(Loan)
Structures and Their Function
Landfill area
This area is for safe disposal of landfill wastage. The area is
slope in longitudinal and transverse direction in gentle slope
such that there is a low elevated point at the middle of the waste
protection dam suited at the foot of the landfill area at southern
part.
There is compacted sand cushioning where the standard HDPE sheet
is over laid to protect the landfill leach ate to percolate to
the ground water and to collect at the low elevated point where
a leach ate collection ditch is constructed over the whole area
of land fill. There is 1.00 foot to 1.50 feet thick gravel lying
on the HDPE sheet. There are 14.00 nos. landfill gas vent of vertical
cylindrical bolster of GI mesh wire (dia.1000mm) filled with gravel/stone
for cost-effective landfill gas vent system.
Function
The landfill wastes are unloaded by garbage tipper and after then
by the chain dozer it is compacted and leveled. The height on
the left is kept 2.00 meter. The wastage of one day is spread
on a cell i.e. one day operating area approx. covers a size of
40.00 square meter. The leveled and compacted wastage is covered
with covering material as soil at a thickness of 6 to 12 inches
compacted layer. The waste covering soil is spread by the wheel
loader both top and slope of cell. The cell for a day is guided
by bamboo stick. The anti odor chemical phenol is spread all over
if fall smell occurs.
Septage Settlement Tank (SST)
This is the semi underground septic tank about 1.00 meter below
the ground level of capacity 150.00 cubic meter which is covered
by CGI sheet. In these tanks, fresh septage is poured. When the
Septage is filled, it is withdrawn into Sand drying Bed (SDB).
This is left for few days for drying process. The liquid is collected
to a man hole passing through the filter media of different grade
of gravel of the bed.
Sand Drying Bed (SDB)
The Sand Drying Bed is Just near the Septage Settlement Tank.
The drying bed has five different grade of gravel varying large
to small from bottom to top. The size of bed is 41.15 by 41.15
meter divided into seven parts by concrete wall, each is connected
by side canal from where septage flows to the bed. The main function
of the SDB is to settle the solid waste on the bed and to filter
the liquid in primary level through its five different grade of
gravel of the septage. This is withdrawn from the Septage Settlement
Tank (SST). The dried solid waste is used as compost fertilizer.
Treatment Plant
1) Horizontal Reed Bed (HRB)
2) Vertical Reed Bed (VRB)
The mixed liquid waste (i.e. primary treated septage and landfill
leach ate) enters horizontal reed bed through an intermittent
tank and then to vertical reed bed through an another intermittent
tank. The Reed bed System (HRB &VRB) in series has been designed
for the treatment of 75.00 cu mtr/day of septage and 40.00cum
mtr/day of solid waste leach ate. The HRB has a surface area of
1105.00 Sq. mtr and the VRB a surface area of 2203.00 Sq. mtr.
Both the reed beds have been designed as open ditches excavated
below the natural ground level. The base of the HRB has 1% longitudinal
slope and a 2% transverse slope in two ways whereas that of VRB
have only 1% longitudinal slope.
Composting Area
This is for secondary segregation of solid waste and for composting
purpose. It is compounded and there is a small shed inside it.
The composting is not running nowadays due to lack of personnel.
Cut off drain
There is a cut off drain of 555.00 meter long around the north
to East side of landfill site to divert the rain water as well
as existing canal to save the landfill site.
Surface Water Collection Basin (SWCB)
A surface water collection basin of about 270.00 cu mtr is constructed
at the specified site location. The SWCB serves not for storing
the run-off water carried by the surface water cut off drain constructed
in the next upper terrace, but also for diluting the treated effluent
of RBT (Reed bed treatment) system before being discharged into
Seti River.
By:
Jnr Er. Padam Lal Adhikari
