MAIN CONTENS OF THE GUIDELINE
1. Compliance with Relating Laws
Operation and maintenance of WTP should be conducted in
accordance with rules, and standards formulated by relating
laws. For instance, in article 21 of Sewerage law, it is
stated that the general manager of public sewerage system
shall maintain and upkeep the sewage treatment plant as
stipulated by the Cabinet Order. Also, treated wastewater
quality should meet the standards regulated by sewerage
law.

Laws and regurations relating O&M of WTP in Japan are as
follows.
1) O&M for WTP
(1) Qualified Engineer regulated by sewerage law
(2) Necessary O&M contents regulated by sewerage law
and enforcement order
2)

Effluent Water Quality
(1) Regulated by Sewerage law and Water Pollution control
Law
Treated Wastewater Quality Analysis(Items,frequency,
record, etc.) is also regulated by Sewerage Law.
(2) Others (Special area for designated water resource,
Dioxin Control Law, PRTR; pollutant release and
transfer register)
3) Sludge Management (Treatment, Disposal, Reuse)
regulated by Sewerage Law
In Article21-2, Treatment of generated sludge is
regulated as follows.
(1) For deposits such as sludge coming out of the sanitary
inlets and sewage treatment plant and other materials
ruled by cabinet order structure,the general manager
of public sewerage system shall have them properly
disposed to accomplish the appropriate maintenance
of public sewerage system and to prevent the harmful
substances proliferation in accordance with the
standards in accordance with the standards set forth
in the Cabinet Order.
(2) The general manager should make efforts to reduce the
volume of generated sludge by dewatering, incineration,
reuse, etc.
4) Air Pollution (regulation for discharged exhaust gas),
Noise and Vibration, Odor Control (Standards of
Discharged Oder Substance Concentration), Energy
Saving (energy saving law,or Law concerning the
Rational Use of Energy), etc. are also regulated in
relating laws.
2. Staff Assignment Plan and Management System
1) Staff assignment plan is made as a part of O&M
implementation plan including clarification of O&M
contents and establishment of O&M Manual (Sewer
System and WTP).
2) Management System (Resident type control or Patrol
type control, Remote monitoring and control, Direct
management or Entrustment, Night shift, Working hour,
etc.) should be also considered.
3. Securement of Qualified Engineers
Following qualified engineers are necessary for O&M.
1) Engineers for O&M regulated by Sewerage Law
2) Legal Work Chief at Insufficient Oxygen Site
3) Lead Engineer for Electricity
4) Lead Engineer for special facility and control
hazardous materials (ex. Boiler, storage of Oil,
generator)
5) Responsible engineer for Safely Work
6) Others
Also, engineers training plan is necessary for rational
O&M.
4. Sewerage System Ordinance and User Charge
Sewerage System Ordinance, which formulates following
issues is needed before the commencement of user
service and O&M.
1) Connection facility to public sewer system and its
management
2) Wastewater pretreatment facility before discharging
of wastewater to public sewer system and its control
3) User Charge (Specific Value, and system in
Administrative area)
4) Basic Principles and Calculation methods for user
charge
(1)Subject matters for charging
(2)Revise of user charge
(3)Long term balance
(4)Basic Concept for calculation of User Charge
("Basic Concept of User Charge Manual" has been
published in Japan)
5. Cost Estimation for O&M
Following expenditures are usually needed for O&M of WTP,
and budget plan. should be made based on cost estimation
for these items. Calculation and estimate method of each
item is necessary for making up of budget plan.

Personnel expenditure,
Fuel expense, heating and lighting cost,
Electricity expenses for main treatment facilities
like Pumping Facility, Blower, etc.
Repairs expense,
Sludge transportation, disposal, or recycle cost,
Outsourcing cost (Entrustment Contract price with
O&M entity)
Raw material and chemical cost
Others
6. Entrustment of O&M
The owner or general manager has a basic responsibility
for O&M of WTP, and usually some part of O&M is entrusted
to selected private O&M entity. There are several types
of O&M contract. In Japan service contract has been
widely adopted. However, recently, the number of
municipality, which adopts management contract, has been
increasing because of its efficiency.
In this case, owner and selected O&M entity make a
contact, and relation between owner and O&M entity
regarding share of responsibility, scope of entrustment,
etc. is described in O&M contract documents. Moreover,
scope and contents of entrusted O&M, boundaries of O&M
entity's responsibility, measures in the case that
expected operation is not performed, evaluation of
performance, reporting issues from O&M entity to the owner
etc. should be clearly defined in contract documents.
In Japan, special committee, which consists of central
and local government, and Japan Sewage Works Agency was
established to study above mentioned issues, and "Guideline
for introducing management contract" was published.
7. Monitoring and Control of Specified Facilities
Relationg to Industrial Wastewater
Industrial wastewater sometimes contains hazard and toxic
substances and before the wastewater of the specified
facility is connected to public sewer system, following
items should be considered and implemented.
1) Confirmation of Regulation (Sewerage law and Water
Quality Control Law)
2) Establishment of Monitoring and Control Method
(1)

Reporting of the install of a specified facility
(2) Improvement orders if pretreatment facility is not
enough
(3) Enforcement of effluent standards (wastewater
discharge restrictions)
(4) Penalties for violations of the effluent standards
Information Collection of specified facility (Number,
Type, Flow Rate, Location, etc.)
8.

Forecast of Inflow Wastewater for Rational
Wastewater Treatment
Forecast of Quantity (Domestic, industrial, commercial,
groundwater, etc.) and quality of inflow wastewater is
required for decision of WTP operational mode such as
return sludge ratio, retention time, air supply amount,
etc.
9.

Ledger and Daily, and Monthly Report
The results of O&M or condition of sewerage systems
should be recorded in proper format and reported to
the authority. Usually, following ledger, or report
are made and recorded in Japan.
1) Fixture ledger, Facility ledger, Work history ledger
in WTP
2) Pretreatment ledger
3) Connection pipe and facilities ledger
4) Operation planning and record
5) Maintenance report
6) Water quality analysis report