Framework of Collection/Treatment
of Septage and Good Practice ofSeptage Management in Japan
Dr. Kiyoshi Kawamura
Former Affiliation:
Graduate School of Science and Engineering,
Saitama University

1

A short history of the development inon-site technologies and systems tomanage night soil and grey water inJapan2

Development of on-site technologies/systems～End of the World War II (1945)
Social circumstances
・Night soil was used as a valuable fertilizer in agriculture.
Technologies and systems
・Night soil was stored in vaults and traded for money orvegetables.
・Grey water was directly discharged to the nearby waterways.

3However・Recommendation of no-use by the Occupation Force to prevent
parasitic diseases
Modernized traditional
・Spread use of cheep chemical fertilizers
style non flush toiletetc.
1945～1955
Social circumstances
・Drastic decrease of night
soil use in agriculture
Illegal and/or unsanitary
disposal of night soil
Technologies and systems
・Beginning of night soil
treatment facility construction(Anaerobic digestion +supernatant treatment)

A hole for dropping excreta
Anaerobic digesters4
http://www.okikou.or.jp/nagai_cc/nagai%20si.htm

Social circumstances
Japanese style・Requirement of cistern flush toilet use
cistern flush toilet
Technologies and systems
・Beginning of household type tandoku-shorijohkasou use
・Grey water was still directly discharged tonearby waterways.

BlowerDisinfection chamber

Sedimentation separation chamber

Aerationchamber

Sedimentationchamber

An example of household type tandoku-shori johkasous
51955～1965
Social circumstances
・Start of economic development
・Urbanization and industrialization
・Spread of public nuisanceTechnologies and systems
・Beginning of medium- and largescale gappei-shori johkasou use
to treat grey water together
1985～1995Social circumstances
・Requirement of access to water
environment to get familiar with it
Technologies and systems
・Development of household typegappei-shori johkasous with theeffluent BOD≦20 mg/L

An example of medium-scale
gappei-shori johkasous

An example of household type6
gappei-shori johkasous

Currently available off-site and on-site
technologies and systems to manage
night soil and grey water in Japan7

Major night soil/grey water treatment systems
Night soil＋
grey water

Off-site
Wastewater
treatment facility

Off-site

On-siteNight soil
Septage injohkasous is calledjohkasou sludge.

Treatment
plantOn-site

On-site(From 1997)8

An example of night soil treatment facilities
Receiving/pretreatment

Night soil
Johkasousludge

Central inspection room

Main treatment

Denitrification

Nitrification

Deodorization

Advanced treatment

Second- Reaerary
ation
denitrification

Dehydration
http://www.furano.ne.jp/eiseikumiai/files/9_1.jpg

9Concept of a night soil treatment and organic
waste recycling center (applied from 1997)a) Night soil treatment facility
Night soil
Pre tre atme nt

Solid- liqu id
se paration

B iologic altreatme nt

Advan c ed
treatmn et

Disin fe ction

Discharge

Disin fe ction

Reuse

Joh kasou slu dge
Sludgetreatme ntb) Night soil treatment and organi waste recycling center
Waste wate r treatmen t

Nigh t soil
Pre tre atme nt

Solid- liqu id
se paration

B iologic altreatme nt

Advan c ed
treatmn et

Joh kasou slu dge

Disposer
Kitch e n garbage

Live stoc k's e xc re ta

Organ ic waswte fromrestau rants, e tc .

An ae robic
digestion

De hydration

Me th an ere cove ry

Activate d carbon
Phosph ate

Fue lGe n eration ofEle c tric ity(Use in c en te r)
En e rgy re c overy

High qu ality
compostRe source rec ove ry

Use in th e outside of a c e nter

Agricu ltu ral use

10Time course in reversing the rate ofpeople served by flush toilets and therate of people served by vault toilets

11Trend in night soil/grey water management
140
Self-management ofnight soil

Outside area of administrative
manegement for night soil

ToiletNight soil storage tank use

Site Object

Population (million persons)

120Onsite

Njght
soil
only10080Vault and vaccum toilet use
Njght
soil

60
Cistern flush toilet use

40Offsite＋GreywaterSewerage use

200

Population of flush toilet use
10.3％ (9.84 million persons)

Fyscal year

Population of non flush toilet use
7.0％ (8.33 million persons)・Gappei-shori johkasou use includes rural sewerage system use.
・Off-site system includes sewerage system and rural sewerage system.

12

Legal framework in management of night
soil and johkasou sludge

13Legal framework for johkasousStructure
・The Building Standard Law (1950)
It defines johkasous as facilities to be installed before discharging the filth from flush toilets except to sewerage systems.
・Structural Criteria of Johkasou (1969)
It was the first nationwide structural criteria of johkasous.
The Criteria has been revised several times until now. The latest
version has been applied from 2006.

BOD≦20 mg/L

BOD≦20 mg/L
T-N ≦20 mg/L

BOD≦10 mg/L
T-N ≦10 mg/L
T-P ≦ 1 mg/L

BOD≦ 5 mg/L
T-N ≦10 mg/L
14

Structure・Calculation standard for the number of users for design of ajohkasou corresponding to building use (JIS A 3302-2000) (2000)
A Japanese Industrial Standard, of the latest version, to be
applied for calculating the number of users for design (NUD) ofa johkasou corresponding to the purpose of a building use

House with a floor spaceof 130 m2 or lessHouse with a floor space
more than 130 m2

Meeting place with afloor space of A m2

Johkasou for NUD of 5Johkasou for NUD of 7

Johkasou for NUD of0.08A
15

Management・Waste Management and Public Cleansing Law (1970)
It designates the details of suppression in emission and optimization of treatment/disposal of wastes.
It defines night soil (including johkasou sludge) as an item ofwastes.
It stipulates that each municipality has to・endeavor to take the measures necessary for the proper
management of municipal waste (MW),・establish a plan for the management of MW (municipal waste
management (MWM) plan),・collect, transport and dispose (including recycle) the MW,according to its MWM plan, before occurring the difficulties
against the conservation of its living environment .

16

A MWM plan consists of two plans.
① A basic plan for MWM: to be the basic policy for MWM of amunicipality based on its long-term perspective② A implementation plan for MWM: to decide the specifics ofsuppression in emission, promotion of reduction and recycling, collection, transportation, disposal, etc. of MW, in eachfiscal year based on the MWM plan
In addition, the both plans consist of two parts related to garbage
and domestic wastewater.
Night soil and johkasou
sludge has to be managed
as well as garbage underthe basic and the implementation plans.
MWM plan(Long-term plan for
10-15 years)

Implementation planfor MWM(Plan for each fiscalyear)

Basic plan for garbage
management

Inplemetation plan for
garbage management

Basic plan for domestic wastewater management

Implementation planfor domestic waste17
water management

Basic plan for MWM

Management・Johkasou Law (1983)
It regulates installation, checking/normalization, cleansing andmanufacturing of johkasous, and designates the system tooptimize these works.
（In general, checking/normalization and cleansing are called
collectively maintenance.）
It states, in the Article 52, “Each municipality has to endeavor
to collect the sludge and scum, etc. that is generated in andcollected from johkasous within its administrative area, andto treat them in its own night soil treatment facilities”.

18Facility for accumulation of johkasou
sludge and positioning of cleansing(composed of desludging and washing)in the framework of johkasou management

19

Accumulation method of johkasou sludge
classified by the treatment capacity or NUD
NUD: number of users for design

・Small-scale johkasou : for NUD of 5 to 50
No special facility for sludge accumulation
・Medium-scale johkasou : for NUD of 51 to 500
A johkasou with a flow equalization tank for
NUD of 101 or more has to be equipped asludge thickening-storage tank.

Small-scale FRP made johkasou

・Large-scale johkasou : for NUD of 501 or more
A johkasou with a flow equalization tank has
to be equipped a sludge thickening equip- Medium-scale FRP made johkasou
ment and a sludge storage tank.
For a johkasou with no facility for sludge
thickening and storage, it is required toaccumulate sludge in the johkasou itself.
20
Large-scale RC made johkasou

Frame of johkasou management and positioning of cleansing under the Johkasou Law【Manufacturer】
Manufacture【Johkasou nmanager(normaly Owner)】
Technical
standard

Nortification

Installation/
construction

Guidance

Beginning of use
Technicalstandard
Technicalstandard

Structural criteria

Nortification

Ckecking/ 【Ckecking/normaliation
normalization vendor】 3-4 times/year
Guidance

Cleansing【Cleansingvendor】 1 time/year

Inspection【Specified inspection
agency】 1 time/year【Prefecture】【 Municipality】

Guidance

Report21

Necessary works at site : Installation, checking/noralization, cleansing and inspection

Installation
Checking/
normalization
Cleansing

LegalInspection

22

Number of organizations and personnel forjohkasou worksJohkasou manufacturer
Johkasou installation vendor

27 manufacturers
33,593 vendors
83,205 persons(Request)

Johkasou manager(Qwner and/or user)

Specified inspection
agency(Johkasou technicalsupervisor)

Inspection(For a johkasou with
NUD of 501 or more)

26,658 persons

65 agencies
1,210 persons(Entrusted)

Checking/normalization
Johkasou checking/normalization vendor
12,871 vendors
72,521 persons(Entrusted)
CleansingJohkasou cleansing
vendor5,375 vendors
15,117 persons
23(As of the end of FY 2010)

Items of cleansing defined by Johlasou Law
Purpose・Recover normal treatment performanceContents・Removing sludge (desludging)
・Washing the johkasou
・Confirming and reporting, if there are faults or defects in thejohkasou

Frequency
・Once a year at least

Responsible organization
・Johkasou cleansing vendor which should be registeredResponsible technician
・Johkasou cleansing technician who should be certified
24

Concrete works of cleansing

25

Cleansing works【Preliminary step】☆ Deciding the necessity of removing sludge
To decide the time when sludge should be removed based ontreatment performance of and sludge accumulation in thejohkasou.
Treatment performance is judged by theresults of checking/normalization works
and/or annual inspection.
Sludge accumulation is checked byinserting a pipe.

26

☆ Desludging (removing sludge)
The method and the volume of removing sludge has to bedecided depending on the function of each unit equipment.

27

☆ Washing
After desludging, equipment is washed to be clean.

☆ Water filling
After washing, water corresponding to the amount of removed
sludge is added.

☆ Transport of removed sludge
Sludge is transported to a night soil treatment facility or a night
soil treatment and organic waste recycling center for treating.28