National Institute for Land and Infrastructure Management, abbreviated
as NILIM, is only one national research institute in the fields of
housing and social infrastructures, and is a part of Ministry of Land,
Infrastructure and Transport, Government of Japan. NILIM performs
comprehensive surveys, testing, researches and development
(hereinafter referred to as research and development) concerning
the planning and drafting of policies regarding technology for the
provision of infrastructures to use, develop and conserve the
national land. Specifically, it conducts research and development to
achieve the following goals.
1） Policy Support: research and development to help propose and
and draft policies
2） Formulation of Technical Standards: research and development
concerning the formulation of technical standards in conformity
with laws
3） Technical Support: providing technical guidance with research
and development necessary for public works execution by the
ministry and the local governments
NILIM was established in April, 2001 through reorganizing Public Works
Research Institute, Building Research Institute and Port and Airport
Research Institute, each of which was attached to the ministry.
Research and development of NILIM covers river,road,sewerage system,
harbour, airport, housing, building construction, and urban development,
and its organization is shown in Fig.1

On the other hand, Public Works Research Institute, Building Research
Institute and port and Airport Research Institute, currently as
incorporated administrative agencies, perform research and
development that must be reliably performed for the public good
by stabilizing the lives of the people and the public economy and
that aren't necessarily to be carried out directly by the national
government, but that might not necessarily be carried out if left
up to the private sector

The website of NILIM, http://www.nilim.go.jp/english/eindex.htm, provides
more information of the institute and each department as well as a full
version of its quarterly "NILIM NewsLetter."


Sewerage is a fundamental infrastructure for our life, contributing
to a comfortable living environment, water quality conservation of
public water areas and prevention of inundation.　Currently, not a
few sewage works have a task that old sewage facilities should be
rehabilitated or upgraded, and to ensure water safety in total
watersheds by reduction of water risk regarding environmental
hormones, viruses, protozoa, etc. is another urgent one.
Water Quality Control Department performs relevant researches to
recommend solutions to these and to seek for what sewerage management
ought to be. The organization of the department is shown in Fig.2,
and the related URLs are as follows.
Water Quality Control Department:
http://www.nilim.go.jp/english/organization/water/ewater.htm
Wastewater System Division:
http://www.nilim.go.jp/lab/ebg/eindex.htm
Wastewater and Sludge Management Division:
http://www.nilim.go.jp/lab/ecg/eindex.htm

　　

Wastewater System Division
　

Wastewater System Division performs researches in the arenas of sewerage
planning, stormwater control and sewer system in order to manage and
improve sewerage as an indispensable infrastructure.

Sewerage planning : In response to changes in social and economic
conditions, sewage works are required to take positive roles with
their basic and potential functions, and effective planning methodology
should be sought with a view to ecosystem conservation, sound water
ecycle, rehabilitation of sewage facilities and continuous functioning
even in disasters. The division conducts researches on benefit measurement
of sewage works and GIS (Geographic Information System)utilization in
sewerage planning. Researches on assessing garbage grinder introduction
to home in sewerage districts are also conducted.

Stormwater control : Urbanised areas are still at risk of inundation
especially due to torrential rains, and not only quantity of stormwater
runoff but also its quality has adverse effects on receiving water bodies.
As comprehensive stormwater controls are needed, the division conducts
researches on best stormwater control planning such as co-ordination
between sewage and river works. As for runoff quality, nonpoint pollution
from urban areas is measured for its estimation and reduction.

Sewer system : Sewer system is a substantial asset reaching 370
thousand kilometres in length in all Japan. Without proper management,
its performance is deteriorated with possible facility collapses sometimes
making cave-ins on roads. To promote better management, the division
conducts researches on maintenance and life cycle cost of sewer system
as well as road cave-ins due to sewers. In addition, the division performs
surveys on disaster damages of sewage works and provides technical
assistance to local governments responsible for sewage works.

Wastewater and Sludge Management Division

Sewerage systems have greatly helped to improve sanitation and aquatic
environment. Furthermore, new needs have arisen in recent years due to
issue related to increase of reuse of treated wastewater and prevention
of global warming. Therefore, Wastewater and Sludge Management Division
performs researches on wastewater treatment, especially technical
standards for wastewater reuse systems, risk management of pathogens
and chemical substances and Life cycle assessment of sewerage systems.

Technical standards for wastewater reuse systems : The amount of
treated wastewater has risen to 13.7×109 m3 per year in Japan in 2003,
ans reuse of treated wastewater as a valuable resource is increasing.
The division performs research on the setting of the technical standards
of treated water quality to protect human health and impact of treated
wastewater on ecosystem to create comfortable water environment.

Risk management of pathogens and chemical substances : Recently,
large scale mass infections by pathogens such as Cryptosporidium have
occurred. And impact of chemical substances such as EDC(Endocrine
Disrupting Chemicals) is feared. The division performs researches on
risk management of pathoges and chemical substances in treated wastewater
and receiving water bodies.

Life cycle assessment (LCA) of sewerage systems : Recently, the need
of reduction of greenhouse effect gas from public and private sectors has
arisen. The division performs researches on LCA of sewerage systems and
control of greenhouse effect gas such as N2O and CH4 emitted from wastewater
and sludge treatment processes.

Experimental Facilities

To conduct various researches, the department has experimental facilities
on the premises and in the other sites such as a nearby wastewater treatment
plant. Kohoku Integrated Experimental Facilities (hereinafter referred to
as Kohoku Facilities), located in Kasumigaura Treatment Centre, is facilities
enabling to use influent or effluent on site. Several main experimental
facilities are as follows.

"Sewer Hydraulic Experimental Facility"
(Photo 1) is to observe and obtain data
of flow especially in large scale
stormsewer. It has three models with
diameters of 500mm, 250mm and 125mm, and
the largest model has 24m in length.
Photo 1
Sewer Hydraulic Experimental Facility
"Pressure Sewer Experimental Facility"
(Photo 2), located in Kohoku
Facility, is to simulate the actual
conditions inside pressure sewer
and investigate sulphide formation.
The sewer is made of ductile iron,
with 100mm in diameter and 1,800m
in length.
Photo 2
Pressure Sewer Experimental Facility
"Cryptosporidium Laboratory" (Photo 3)
is to measure cyst and oocyst of
Protozoa through pre-treatment,
microscopic examination and/or
polymerase chain reaction method. The
structure of this laboratory has P2
level of safety to measure contagious
Cryptosporidium.
Photo 3
Cryptosporidium Laboratory
"Advanced Activated Sludge Processes
Experimental Facility" (Photo 4),
located in Kohoku Facilities, is
composed of a primary sedimentation
tank, reaction tank,final sedimentation
tank and so forth. It is to investigate
various types of advanced activated
sludge processes.
Photo 4
Advanced Activated Sludge Processes
Experimental Facility
Toshiaki Yoshida, Senior Researcher
　 　 Wastewater System Division, Water Quality Control Department,
National Institute for Land and Infrastructure Management
Ministry of Land, Infrastructure and Transport, Government of Japan