Partial amendment of Sewerage Law was made on June 2005, and came
into forth in November 2005.

Construction of Sewerage System has been promoted to respond several
social needs such as better life environment, preservation of water
quality, and prevention of flooding in urban area, and corresponding
to the changes of social structure and diversification of sewerage role,
sewerage Law has been amended several times.

In this amendment, promotion of advanced wastewater treatment,
establishment of regional flood control system and immediate response to
the accident when toxic substances flow into wastewater treatment plant
were formulated to cope with recent important issues such as safety
improvement of the lives of people and preservation of global environment.

Water quality in public water bodies has been gradually improved
by promotion of sewerage systems, but in closed water bodies like
bays and lakes, the water quality has not been so improved.
Therefore, the advanced wastewater treatments, especially effective
removal of phosphorus and/or nitrogen, which are the cause of water
quality deterioration, are needed.

According to the sewerage law, each prefecture shall set forth
basin-wide planning of sewerage systems for the purpose of
bringing the environment conditions of subject area to environmental
water quality standard, and in this amendment, it was formulated
that target reduction amount and reduction method for nitrogen
and phosphorus in each WTP should be determined in comprehensive
basin-wide planning of sewerage systems for closed water bodies
like lakes and bays.

Also, in amendment of sewerage law, it was formulated that the

local government may offer a surplus nitrogen and phosphorus
reduction over and above their current target removal amount
to prefectural governments with the agreement of related local
government.  In this case, it is possible that the local
government, which offers surplus reduction, can request the
part of O&M cost in WTP to reduce surplus nitrogen and
phosphorus to related municipalities.

Sewerage systems has played important role to contribute to

sound development in urban areas by stormwater drainage and
discharge to public water bodies.　However, recently inundation
in urban area has frequently occurred by concentrated heavy rain,
and as a part of effective measures for inundation, regional
stormwater drainage systems were established.

According to the sewerage law, Regional Sewerage Systems were
defined as sewerage controlled by a local government, characterized
by the capacity to discharge effluents discharged from more than
two municipalities, and provided with a sewerage treatment plant.

Then, before amendment, wastewater treatment plant should have been
involved in Regional Sewerage Systems, and stormwater drainage systems
from more than two municipalities without wastewater collection and
treatment systems were not regulated.

In this amendment, regional flood control system, stormwater drainage
systems from more than two municipalities has been newly regulated
by itself, and prefecture can promote effective stormwater drainage
systems.

Recently, the accident that wastewater which includes toxic substances
like cyanide, cadmium, arsenic, etc. and oil inflows into wastewater
treatment plant, has occurred once in a while, and immediate and rational
response to the accident are needed to prevent the discharge of toxic
substances and oil to public water bodies.

In this amendment, when toxic substance like cyanide or oil that
may induce health hazards or damage the living environment flows
into public sewerage systems, a person or persons who use the public
sewerage systems for discharging effluent from the specified facility
shall take emergency measures and inform to the manager of public
sewerage systems immediately.

In this amendment, it was formulated that the advanced wastewater
treatment plan shall be involved in comprehensive basin wide planning
of sewerage systems, and regional sewerage system for stormwater
drainage from more than two municipalities was established.  It is
expected that the sewerage system will play more important role for
human's safety and better water environment by this amendment of
the law.