Tokyo Bay-side L andfill〜 Structure, Management,Land-use〜Tokyo Bay-side Landfill

Recycling-oriented societies ─Tokyo and Beyond

One of the biggest challenges for a mega city is securing space for final disposal sites.
As the concentration of urban functions has progressed, the degree of diﬃculty becomes
more serious. Tokyo has been facing the same challenges and found the answer in bay-side
disposal sites.
Bay-side disposal sites create the potential of new city development in addition toappropriate disposal of waste. Meanwhile, the bay-side is an extremely valuable natural
resource. Therefore, it is necessary to pay utmost concern to the conservation of theenvironment.
To that end, well-planned development, environmentally-friendly structures and construction,
sanitary landﬁlling of waste, and appropriate maintenance and management are necessary.
We, the Tokyo Metropolitan Government, hope to share our experiences and technologies
obtained through the bay-side disposal sites in the Port of Tokyo and that this handbook will
be informative for your city.

I NDEXⅠ Construction

Ⅱ Waste Landfill and MaintenanceⅠ- ⅰ Overview of New Sea Surface Disposal Site ……5

Ⅱ - ⅰ Landfill disposal plan for waste ………………………8

Ⅰ- ⅱ Structure of Shore Protection ………………………6

Ⅱ - ⅱ Landfill operation plan …………………………………9Ⅱ - ⅲ Landfilling, covering soil and leveling ………………9
Ⅱ - ⅳ Leachate treatment ……………………………………10
Ⅱ - ⅴ Landfill gas power generation ………………………11

Basic information of Tokyo
Futatsuzuka Disposal Site

■ Tama area

Area : 1,159.89 km2

Population : 4,082,951（as of January, 2013）
Number of municipalities：30
Discharge

Landfill

Yearly1,206,692 t

6,159 tDaily*

3,306 t16 t

■23-ward area
Area : 621.98 km2

Population : 8,575,228（as of January, 2013）
Number of municipalities : 23
Discharge

Landfill

Yearly3,421,279 t

343,503 t

Daily*

9,373 t941 t*The daily amount is simply calculated by dividing the yearly amount by 365 (days).

2

Sea Surface Disposal Site

Ⅲ Land-use after closure
Ⅲ - ⅰ The Port and Harbor Plan of the Port of Tokyo ………………………………………………………12
Ⅲ - ⅱ Plan for land-use of New Sea Surface Disposal Site ……………………………………………13
Ⅲ - ⅲ Case: Land-use at the former Central Breakwater Inner Landfill Site ………………………13
Umi no Mori (Sea Forest) Project

Basic information of Tokyo bay-side disposal sites
The Tokyo Metropolitan Government is now installing and managing two bay-side disposal sites in the Port ofTokyo. These disposal sites receive incineration ash and incombustible residue from municipal solid waste in the
23-ward area of Tokyo, sludge from water and sewerage, and industrial waste* after intermediate treatments suchas incineration and pulverization. The Tokyo Metropolitan Government Bureau of Port and Harbor is responsible
for the construction of the disposal sites while the Bureau of Environment is responsible for the landﬁlling of waste.
* Composed of combustion residue, sludge, metal scraps, and the like discharged from small and medium enterprises located in Tokyo.

No.1

Central Breakwater
Outer Landﬁll Site

A Block

Central Breakwater
Outer Landﬁll Site

No.2

Central Breakwater Outer Landﬁll Site
■Start of operation : 1977
■Landﬁll area : Part 1 (Dredge soil/soil dug fromconstruction sites) : 115ha

B Block

Part 2 (Waste that has undergoneintermediate treatment only): 199 ha■Accumulated volume of landﬁlled waste :54.2 million tons（as of FY2011）

G Block
C Block
New Sea Surface Disposal Site

New Sea Surface Disposal Site
D Block

F Block
E Block■Start of operation : 1998
■Total area (A - G) : 480ha■Landﬁll area : A ‒ E (Waste) : 319ha
F ‒ G (Dredge soil/soil dug fromconstruction sites) : 161ha■Accumulated volume of landﬁlled waste :5.8 million tons（as of FY2011）

Port of Tokyo aerial photo chart

3

Ⅰ Construction
Hydrographic condition of the Port of Tokyo
Tidal level

Reclamation by soil（F and G block)Wind rose

Low tide: A. P. ± 0.0 m

N
12%
18
15
12
9
6
3

High tide: A. P. ± 2.1 m

3

calm
1.0%

Arakawa

6W

The western blocks (F and G), where there
will be a container terminal in the future, areE

reclaimed by soil dug from construction sites
along with dredge soil. The double steel-tubing

sheet pile type is adopted for this, which allows
the erection of a pier easily for the purpose of acontainer terminal in the future.

S

Landﬁll by soil and waste (A -- E block)
The eastern blocks (A-- E), where there will bemainly established a vast green space in the
future, are landfilled by soil and waste. The
caisson type is applied after considering theconstruction costs. The thorough seepage
control mechanism is equipped, and on theocean-side, a shallow bottom is developed forbiotic conservation.

E
A〜
Bl
k

oc

G
F〜
oc
Bl

Conditions around New Sea Surface Disposal Sitek

Water depth : −10meters
Seabed : from −10meters to −40meters
Geology of sea ﬂoor : Impermeable viscous soil layer

Port of Tokyo

Tam

aR

ive

r

Tokyo Port Area

Tokyo Bay

4

Ⅰ Construction
Ⅰ-ⅰ Overview of New Sea Surface Disposal Site
Overview of Shore Protection
shore protection, the double steel-tubing sheet pile structure andthe caisson structure. For blocks A to E, where waste is buried, thereclaimed land inside the shore protection is ﬁrst prepared using
dredge soil and soil dug from the construction site, followed by
the commencement of landﬁlling of waste. With consideration to

the type of shore protection, upgrade cycle, and expected lifespan,
the disposal site has sufficient seepage control performance.

Additionally, the front side of the outer shore protection of the
New Sea Surface Disposal Site on the east side is developed with ashallow bottom structure in due consideration of the environment
so that marine resources such as aquatic organisms and ﬁshery（Part.2）

Double steel-tubing
sheet pile type shore
protection
Stabilized type block(Blocks mainly used forburying dredged soil)

Caisson type shore
protection

Central Breakwater
Outer Landﬁll Site

Controlled type block

Central Breakwater
Outer Landﬁll Site

（Part.1）

Stabilized type（Part.2）

The blocks F anused for buryin
construction sit
which no leach

A Block(Blocks mainly used forburying waste anddredged soil)

Landﬁll area : 480ha
Capacity（soil and waste）: 120 million cubic
metersG Block

Ground surface height : A.P. + 6.0 m - A.P. +30m
Total length of shore protection : 13.9km（Outer

B Block

C Block

periphery : 6.5km, Internal partition : 7.5km）
Construction cost of shore protection : 450 billion
yen (budget of Tokyo Metropolitan Government

D Block

and partial subsidy from the national government)

F Block

Total project cost : 744 billion yen

DGround improvement

E Block

products can be preserved.

w

tral Breakwater
ter Landﬁll Site

Overhead view

The New Sea Surface Disposal Site is enclosed by two types of

Waste

Reference

Cross-section view
Stabilized type block（Blocks F and G）

Controlled type block (Blocks A - E)

The blocks F and G on the west side areused for burying soil and sand dug fromconstruction sites and dredged soil fromwhich no leachate occurs.

The blocks A to E on the east side are used for landﬁlling
waste, including incineration ash and sewage sludge, that
requires maintenance, such as scattering prevention andleachate treatment during and after landﬁll operation.

Subsidy system for improvement and maintenance ofport facilities
When a port administrator implements a project which involves
the development of the seabed, shore protection or the expansion
in capacity of a bay-side disposal site by consolidation settling,
they are eligible for a subsidy from the national government. The
subsidy rate is up to one third of the cost. The Tokyo Metropolitan
Government utilizes this subsidy system for the improvement andmaintenance of the New Sea Surface Disposal Site and its shore
protections.

A.P. + 30.0 m (For A block: A.P. + 6.0 m)

B Block

Subsidy system for disposal site improvement andmaintenance

C Block

When a municipality plans regional and comprehensive improvement
or maintenance of waste disposal facilities or recycling facilities topromote the 3Rs (Reduce, Reuse, and Recycle) in an integral manner,a subsidy will be granted for the improvement or maintenance of the
facilities defined in such plans.

Approx. A.P. - 10.0 m

D Block

Deep digging area

Groundimprovement

Groundimprovement

Ground improvement

E Block

Waste

Deep digging area

Dredge soil

Soil from construction（Infrastructure maintenance and improvement）,

soil covering material

The Tokyo Metropolitan Government utilizes this system andis receiving a subsidy for one third of the cost related to theinstallation of the leachate collection system for the New Sea
Surface Disposal Site.

Settling
promotion area

Procedures leading up to the start of construction of the New Sea Surface Disposal Site
The New Sea Surface Disposal Site is constructed after procedures including a long-term forecast of the amountof waste generation and landﬁll disposal, the implementation of environmental impact assessments, as well as
applications for and acquisition of various permissions and notiﬁcations have been completed.

Plan

1990
ʻ92

The New Sea Surface Disposal Site is planned（The Port and Harbor Plan of the Port of Tokyo）

Environmental Impact Assessment
Survey, forecast and evaluation
ʻ93

Submission of the report of Environmental
Impact Assessment (Draft)

Various procedures

ʻ94

The Land Utilization Plan is preparedʻ94 Completion of theprocedures of theEnvironmental Impact
Assessment

Permission/notiﬁcation

1995

2000

ʻ95

Application for the landﬁll license under the
Public Water Body Reclamation Law

ʻ96Acquisition of the Public Water Body
Reclamation License

Advisory council, publicannouncement andinspection of the draft
report, explanatory
meetings, public hearings,
and gathering of public
opinionConstruction

ʻ96

Start of construction

Application for the license of theestablishment of waste disposal facilities
under the Waste Disposal and Public
Cleansing Law and acquisition of the license

ʻ97Start of landﬁlling

Block D is currently
under construction5

Ⅰ-ⅱ Structure of Shore Protection
Feature of seabed

The feature of the seabed under the sea area for the New Sea Surface Disposal Site is that of a thick layer (about
30 m) of very soft viscous soil (N value = 0 or so) deposited as an alluvium on the top, with the layer becoming
thicker toward the southeast direction. Under the central area of the New Sea Surface Disposal Site, a diluvial
deposit under the alluvium forms a plateau.
When installing structures on soft ground, it is common to expect to have a diluvial deposit under the alluvium toserve as a support layer for the structure. However, since the very soft viscous layer (permeability coeﬃcient:around 10-7 cm/sec) deposited thickly on the seabed functions as a suﬃciently impermeable layer, it acts as a
seepage control mechanism required for the waste disposal site.

A

For the joint parts of the shore protection
which utilize the double steel-tubing sheet
pile type

DAC

For the joint parts of the shore protection which utilize
the double steel-tubing sheet pile type at A block, mortar
grouting is applied to form a seepage control mechanism.
Steel tubing φ1,100×13

85

180
76
9

B
φ165.2×9
Mortar grounting

New Sea Surface Disposal Site

Steel-tubing sheet
pile type outer shore
protection（Block G）
For block G, which will be used
as a site for a container terminalin the future land-use plan, theshore protection is constructed byadopting steel-tubing sheet piles
that have a structure suitable forthe improvement and maintenanceof the pier.

A.P. +6.0m

Dredge soil & Soil from construction site

Coating Stones & Bricks

Ocean

Replacement Sand

Coating Stones

Packing
Sand

A.P. approx.-10.0m

SCP

Sea Bottom(Clay Layer)

SCP

Sand Compaction Pile
(SCP)

Steel -tube
Sheet Piles

Cement Deep Mixing

B

Sea Bottom(Clay Layer)

A.P. approx. - 40.0m

Bearing Stratum(Supporting Layer)

6

Ⅰ Construction

Feature of Shore Protection

For the New Sea Surface Disposal Site, its outer periphery and internal partitions are constructed using two
types of structures, the double steel-tubing sheet pile structure and caisson structure, based on the results of acomprehensive study in consideration of the soil condition and economic eﬃciency. Since the New Sea Surface
Disposal Site is a controlled type waste disposal site, all possible measures are taken for water shielding, as wellas the stability of the shore protection. For the stability of the shore protection, and to increase the strength of
the soft viscous soil layer ground, cementitious reinforcement work (the deep chemical mixing method) is applied
to the foundation of the outer periphery and reinforcement by replacement with sand (the sand compaction pilemethod) or cementitious reinforcement is applied to the internal partitions.
As a seepage control mechanism, water-shielding sheets are laid out at the back of the shore protection. In
addition to this, for the joint parts of the shore protection body, mortar grouting is applied to them in the case of
double steel-tubing sheet piles. In the case of the caissons, ﬂexible cylindrical joint ﬁllers, plate joint ﬁllers, asphalt
mastics, and others are applied.
Moreover, steel-tubing sheet piles are installed at a location 10 to 15 meters behind the caisson body. Between
the piles and caisson body, an impermeable zone is formed by premixed treatment soil (permeability coeﬃcient:around 10-6 cm/sec or less) to increase the water shielding performance of the shore protection as a controlled
type shore protection. The premixed disposed soil is prepared by utilizing the soil (viscous soil) from theconstruction site and by mixing cement into the soil.

C

Caisson type outer shore
protection（Block B & C）

A.P. +30.0m

100m of mildly-sloped bank and shallow bottom
CaissonFor blocks B and C, which will not be
used as a site for a container terminal in
the future land-use plan, a mildly-sloped
shore and shallow bottom with a lengthof about 100 meters are constructed.
Thorough seepage control is achieved
to prevent the leachate from waste fromleaching into the groundwater and sea.

A.P. +6.0m

Dredge soil & Soil from construction site
Water Shielding Sheet

Coating Stones
Packing
Sand

A.P. approx. -10.0m

Ocean
RiprapReplacement Sand
SCP

Sea Bottom(Clay Layer)

Sea Bottom(Clay Layer)

Cement Deep Mixing

A.P. approx. - 40.0m

Bearing Stratum(Supporting Layer)D

Mildly-sloped shore protection for biotic conservation
Development of rock beachExpanded development of the habitable environment formarine species is undertaken by creating shallow bottoms
and tide pools on the mildly-sloped shore protection.
The tide pool is made by utilizing the old caissons that wereno longer needed in the Port of Tokyo.
》Concept art of expected natural biota through the improvement
Tide pool
Goby

Shallow bottom

Brown seaweed

Tide pool at low tide

Barnacle

Shellﬁshes & crabs

Tide pool

Actiniae

Tripletooth goby

Emerald bubble

Porifer

Shallow bottom

Concept art of the development

7

Ⅱ Waste Landﬁll and Maintenance
The municipal solid waste from the 23 wards of Tokyo is currently buried at the Central Breakwater Outer Landﬁll
Site and the New Sea Surface Disposal Site. These bay-side disposal sites are crucial facilities as Tokyo s ﬁnal
disposal sites in the Port of Tokyo.
To use these valuable and finite disposal sites for as long as possible and to hand over ownership of theirreplaceable global environment to the next generation, various eﬀorts are being made at the landﬁll disposalsites.
In the past, organic waste was buried without intermediate treatment and led to problems such as bad odors andoutbreaks of ﬂies. At present, however, all the waste is processed by intermediate treatments (e.g. incineration or
pulverization); therefore, the waste received at the disposal sites mainly consists of incineration ash and pulverized
residue. This system contributes to extending the service life of the ﬁnal disposal sites and reduces the operational
expenses of wastewater treatment.

Ⅱ-ⅰ Landﬁll disposal plan for waste
It is essential to secure space for landﬁll disposal sites to maintain and develop urban functions. Therefore, thecurrent landﬁll disposal sites, which assume the very last space in the Port of Tokyo, need to be used for as longas possible.
With this goal in mind, the Tokyo Metropolitan Government has been creating plans to deﬁne the categories ofwaste separation and also project landﬁll waste volume with the goal of extending the service life of the landﬁll
disposal sites. The current plan has a 15-year overall design covering 2012 to 2026, and undergoes review every
ﬁve years.
Landﬁll disposal plan for waste（Excerpt） (unit : ten thousand m ）3

2012− 2016
Waste

8

207

2017-2021
195

2022-2026
195

Total
597

Soil-covering

42

39

39

120

Dredge soil

465

510

390

1365

Soil fromconstruction

245

200

200

645

Total

959

944

824

2727

● Policy of waste reception by type（1）
Municipal Solid Waste
・Waste from households in the 23 wards of Tokyo
・All waste must undergo all possible intermediate treatments for volume reduction
and resource recovery before being transported into the ﬁnal disposal sites.

（2）
Industrial Waste

・Industrial waste from small and medium-sized enterprises located in Tokyo・A certain amount of the waste after undergoing intermediate
treatments is received only if it satisﬁes the receiving criteria.

（3）
Urban Facility Waste

・Waste from facilities such as water and sewerage facilities in Tokyo
・The waste is received after receiving intermediate treatments.