●Messages from Departments and Centers of NILIM

Reconstructing homes in disaster regions:challenges and support
HORIE Nobuyuki
Director of the Water Quality Control Department(Keywords) Great East Japan Earthquake, liquefaction, renewable energy, B-DASH, management
1. State of Japan when the giant earthquake
occurred
As Japan’s society ages and tax revenues fall amid
continuing efforts to raise welfare budgets, thenational debt is soaring. In the midst of global
competition for survival, the Japanese economy has
fallen behind those of China, Korea, and other nations,and deficits have appeared not only in its trade balance
which has supported the importing of energy and foodproducts, but also in its current account balance.
The Great East Japan Earthquake caused massive
damage and casualties over a wide area. As Japanmourns the loss of many lives and works to restore thelives of those who survived, it faces a turning point
and must decide how best to make the most of thisopportunity to rebuild the nation.
2. Damage to sewage systems by the earthquake
and countermeasures
The giant earthquake caused unprecedented damage
to sewage systems. The Minami-Gamo Sewage
Treatment Plant, which receives sewage from most of
the 700,000 residents of Sendai City, and many othertreatment plants at 120 locations along the coast weredamaged by the tsunami. In the Kanto region too,liquefaction on reclaimed land around Tokyo Bay andnear the mouth of the Tone River severely damagedbuildings and other infrastructure, and also lifted up or
pulled out manholes and sewer pipes, filling them withsoil and making the systems unusable. In Urayasu City,

people were forced to live without sewage services
even after the water supply was restored, and in
Miyagi Prefecture, polluted water temporarily seepedout onto the surface of roads.
The Water Quality Control Department dispatched
two-person teams to the site the morning after theearthquake to set up a field headquarters andinvestigate the damage. In total, more than 6,000
employees of regional government bodies andprivate-sector technologists from throughout Japan
went to the disaster region and surveyed the damage inspite of fuel shortages. A committee set up jointly by
the Ministry of Land, Infrastructure, Transport andTourism and the Japan Sewage Works Association to
study reconstruction technologies (chaired byProfessor Hamada of Waseda University), which acted
as our administration office (content-related),presented three proposals for emergency andtemporary restoration and for final restoration, 1month, 2 months, and 4 months after the disaster.
Table 1 shows the causes of sewage system damage
and countermeasures taken. In the treatment plants on
the Tohoku Coast, which had suffered almost nodamage in the past, the tsunami caused unprecedented
damage to their electrical and mechanical equipment.
Under the impact of long-duration cyclic vibrations,pipes in reclaimed land in the Kanto region suffered
severe damage caused by widespread liquefaction
rather than by the conventional problem of backfill.
Present earthquake resistance guidelines contain little

Table 1. Major damage to sewage systems and countermeasures
Cause
Tsunami(Wave force, floatingdebris, inundation)

Earthquake motion
Liquefaction
Bank deformation
Ground settlement
Power failure
Fuel or chemical shortage

Treatment plant
Destroyed structure or equipment
 Load bearing structure*
Damaged equipment
 Elevating, adopting waterproof doors *Gas holder washed away
 Countermeasures to prevent washing away *Equipment damaged or displaced
Pipes damaged or displaced Countermeasures under present guidelines
Sloshing*New countermeasure
Pipeline
Pipe bridge washed away  Inverted siphon*
Blockage/manhole lid displaced Anchored manhole coverInundation  Flap gate, movable standby pump*

Manhole uplifted or displaced Completion of countermeasures under present
guidelines*
Lateral pipe uplifted or pulled out Ditto, and flexible joints*(Blockage with sediment/road caved in)(Inundation, poor drainage)
Manhole pump stopped  Portable generator(Inundation, poor drainage)
Treatment stopped  In-house generator
Treatment stopped  Increase stock*Present guideline = Guideline to Sewage System Equipment Seismic Resistance Guideline

●Messages from Departments and Centers of NILIM
Table 2. Special features and major effects of the B-DASH revolutionary technology (2011)
Name (Location)
Energy Management System Using Super
High-efficiency Solid-liquid Separation
Technology (Nakahama Treatment Plant, OsakaCity)
Kobe City, Higashi-nada Treatment Plant,
production of renewable energy (same treatmentplant)

Corroboration Technology and Major Effects・ Super high-efficiency solid-liquid separation: compact, increases sludge
recovery・ High-temperature digestion of a carrier containing garbage: generates
more gas and is extremely compact.
・ Smart hybrid electric power production: supply/demand control, full use
of gas・ Steel digestion tank containing biogas: increases gas production, lowers
cost
・ High efficiency heating using sewage heat: saves energy, reduces CO2
・ Package biogas refining: lowers costdetailed guidance concerning tsunami. With toppriority on drainage and sterilization to protect
residents from contact with polluted water
overflowing sewage systems, and to prepare for cases
where restoration takes a long time, the committee has
proposed gradually improving treated water quality, as
well as yardsticks for target water quality andrestoration periods. The backfilling method of
preventing liquefaction at pipelines, which wasproposed and included in guidelines after the Chuetsu
Earthquake, has only been implemented a few times,
but field surveys confirmed that the method iseffective. Regarding how to provide effective tsunami
countermeasure nationwide, which is a major
challenge, the committee issued its fourth proposal on
March 8 and will complete a full report at the end of
this year.
3. For new energy and city planning
The shortage of electric power will continue for along time and increased imports of fossil fuels havepushed up electricity prices and CO2 emissions.
Meanwhile, electricity consumed to treat contaminatedwater accounts for almost 1% of domestic
consumption, and sewage sludge, etc. constitutes alarge source of potential energy. In addition to priorresearch, beginning in the latter half of 2010, newmeasures were preparedand revolutionary
technologies such as for capturing energy fromsewage sludge were verified and described in written
guidelines. Research to verify these technologies inorder to introduce them nationwide, and evenworldwide, called B-DASH (Table 2, 2.4 billion yen),
started in 2011. Facilities to verify methane gas
recovery using local biomass were installed intreatment plants in the cities of Osaka and Kobe anddata is now being gathered; in 2012, measurements
will continue and preparation of a guideline will begin.
Under B-DASH, beginning in 2012 (2.9 billion yen),four technologies—solid fuelization, nitrogen andphosphorus removal, and sewage heat use—wereselected through a public request for proposals.
The Sewerage and Wastewater Management
Department of the MLITT publicly invited proposals
for new technologies to perform advance feasibility

studies. As a large earthquake restoration model,
Kesennuma City started the “Local Production forLocal Use Energy Supply Using Marine Biomass
Project,” and Sendai City implemented the “SewageHeat Recovery Pipeline Renewal Project.”
Regarding the temporary rise in the stored quantityof sludge containing radioactive substances, whichwas revealed in May, a survey showed that in sludge
carried into combined sewage systems by rainfall, theconcentration of radioactive substances increased
30-fold during rainfall. Therefore, tests wereperformed to verify various treatment methods
proposed in response to the public request.
4. Management of a shrinking society
Torrential rainfall is occurring more frequently due
to climate change, and the expert committee of theCentral Environment Council has discussed the threatof new chemicals and is studying the impacts ofchanges in rainfall and sewage treatment.
On the other hand, the population of Japan has
begun to shrink, about ten years after the working
population started to decline, and a skillful response isneeded. The results of past research on low-cost
diagnosis methods, etc. for buried pipelines have been
compiled in the Guideline to Stock Management
Methods, but with severe restrictions on funds,personnel, and other resources, we must also improve
efficiency through comprehensive stock managementof sewage systems.
Worldwide, the international standard ISO55000 for
improving various kinds of infrastructure management
organizations is being drawn up with the participationof the Preparation Committee PC251. In May, various
countries voted on the committee’s proposal, with thefinal voting proposal debated in the Czech Republic inJune; this is scheduled to come into effect in the springof 2014 after the final vote. Along with the domesticcouncil, sewage treatment system operators havebegun to take part in the debate. This deals with theentire infrastructure, and is likely to affect not only theinternational expansion of Japanese corporations, butalso domestic organizations and corporations invarious ways, and so an urgent response is needed.

●Messages from Departments and Centers of NILIM
5. Creating a Worldwide Marine Products
Industry
Today, it is difficult to survive using conventional
approaches, so Japan’s marine products industry mustalso “go global”. In addition to aiming forinternational
standardization
under
B-DASH,members of a sewage system global center are holding
policy and technology seminars in China and Vietnam,
responding to ISO-related trends, and participating inJapan-China-Korea cooperation.
As government systems continue to shrink,comprehensive management to maintain sewage
treatment systems in line with trends in capital will beneeded. W will continue to accelerate our global
response.
References
Document from the Committee to Study Earthquake andTsunami Technologies for Sewage Treatment Systems(Ministry of Land, Infrastructure, Transport and Tourism)