The 2nd Workshop on On-site Domestic Wastewater
Treatment in Asia @Tailand，Dec 2014

Economic assessment of the rural wastewater
treatment using different sewage patterns——based on the application of the household Johkasou in Changshu

Bin Fan, Ph.D prof.
North Research Center for Rural wastewater Treatment
Technology, Ministry of Housingand Urban-Rural Development
Research Center for Ecoenvironmental Sciences, CAS
fanbin@rcees.ac.cn, +86-10-62849142, 100085 Beijing1Outline• Introduction of the rural wastewater treatment
in China• Engineering demonstration of the house‐holdJohkasou in Changshu, China• Economic assessment of different sewage
patterns• Conclusions and proposal2Introduction of the rural wastewater
treatment in China• Current status and the demands of ruralwastewater treatment in China
Rural population in China: ~700,000,000 in 2013
~50,000,000~200,000,000

been
built
~450,000,000 need to be built in
20 years

to live in city infuture

Command of the infrastructure construction:~3000 billion RMB (500 billion USD)

3• Options of the rural sewage patterns in China
On site treatment pattern (OTP)
Indoordrainage

On site treatment
facilitiesEffluent
discharge

Village treatment pattern (OTP)
Indoordrainage

Villagepipelines

Village treatment
facility

Effluent
discharge

Urban treatment pattern (OTP)
Indoordrainage

Villagepipelines

Connecting
pipeline

Urban sewage
systemEffluent
discharge

To optimize the assemble of sewage patterns in aprefectural area is key for economy reason4

• Current problem
local governments prefer more centralized patterns
UTP＞

VTP＞ OTP

Reasons:
 taking for granted that the decentralized treatment is out of date the current domestic equipment technology of the decentralized
wastewater treatment is not satisfying

5

Engineering demonstration of the house‐holdJohkasou in Changshu, China• the practices of the rural wastewater treatment inChangshu

Guideline of the integrative
government of prefectural urban
and rural wastewater treatment(MHURD, 2013)
 Uniformly financing
 Uniformly planning Uniformly building Uniformly running

100 km west of Shanghai

40% of the treatment rate on rural population(totally in China <10%) 90% of the qualified running rate ( generally<20%)6• Current problem in Changshu rural wastewatertreatment– The unit investment cost is too high
– The unit running cost is too highUTP and VTP are the main patterns being usedcurrently, and a kind of on site SBR had been proved failbefore 2012.
main VTP technology used in Changshu
 SBR
 MBR
 Biological contact oxidation7• Introduction of the demonstration engineering
project of household Johkasou– Supported by National Major Project of Science andTechnology on Water Pollution Control and Water
Environment Improvement (2011ZX07301‐003‐09)– site• Fenqiangjing settlement, Dongqing Village, Yushan Town ofChangshu• plain terrain with the typical characteristics of watery area.
• 102 families and about 500 persons, housing along river• The grounds are hardened and made green with plants8

– design• All domestic wastewater being collected, and load of thewastewater per capita is 120l/(person*day)• A kind 5‐person Johkasou with denitrification was selected，
with capacity of 1m3/day/set• Basically one set for two family, but some remote or big families
may independently use one.
The designed influent quality

Influent quality

Item
Quantity of sewage
Peak factor of quantity
Temperature ofsewage
pHBOD5SS
T‐NFatBOD5/T‐N

Design<=1.0 m3/day<613℃～35℃
5.8～8.6<=200 mg/L<=160 mg/L<=45 mg/L<=50 mg/L>=3

The designed effluent quality

Effluent quality
BO <=20 mg/L
D5SS <=15 mg/L
T‐N <=20 mg/L

Notes
Average daily
Average daily
Average daily9

– Totally 55 sets of the household Johkasou wasinstalled• 96 families with two families sharing one• 6 families with one family one set• 1 set for the public toilet
45 day of the whole construction periodDistribution of the Johkasou in
Fenqiangjin settelment

10– Debugging and running• Debugging: 15days, dosing with strains offered by theequipment supplier for quick start.
• Running: by a consigned company with averagely 4times/year。
The main maintenance and running work includes:
 point check of equipment maintenance disinfectant adding, dosage is about 1 kg/year replacement of the turbine diaphragm, once every
2 years ; sludge cleaning, once a year.

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– Effects of the demonstration engineering project• The demonstration engineering project has been run
for 1 year, playing a proper role in improving thehousing and public sanitation and the river water
quality in the Fengqiang settlement• Sometimes effluent COD and TN might be over proof
because the washing water consumption of somefamilies are still low, but the removal of pollutants arealways stably above 80%

12Economic assessment of the different
sewage patterns• Basics of the assessment– All facilities were built in 2012‐2013– Assuming all the facilities being assessed are in samefunction of sanitation and environment protection– All the data are from the fiscal audit report
Table 3. facilities having being built in Changshu after 2012
Sewage patternnumber of

number of

Wastewater

number of

settlements

treatmentloadrural families

facilities(m3/day)（household）

UTP

135

‐

‐

26149

VTP

170

365

4715

7364

OTP

9

164

164

304

（Johkasou）

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• Construction cost
Indoordrainage

On site treatment
facilities

Effluent
discharge

IndoordrainageVillagepipelines

Village treatment
facility

Indoordrainage

Villagepipelines

Connecting
pipeline

Effluent
discharge

Urban sewage
systemEffluent
dischargeThe investment range of the rural wastewater
treatment facilities
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Construction cost of the different sewage patterns
30

pipe works
treatment facilities

onstruction cost（kRMB/household）

25

3.83
20
15
24.69120.54

1018.2355

the moreconcentrated thesewage was, thehigher theconstruction
cost was.

0UTP

VTP
sewage pattern

OTP

UTP>VTP>>OTP
15

cost (kRMB/household)Construction cost of UTP per household of therural wastewater treatment in recent years
30

•25

•
•

Diameter of the pipelines
range from De110~De400

201510502008

20092010year

2011

2012

623 RMB/m in2012
The proposed prices in theguideline of Chinese EPA
 De200 pipeline is 50 ~130 RMB/m,
 De300 pipeline is 150 ~250 RMB/m
 De400 pipeline is 200 ~350 RMB/meter

Reasons include:
1. high workload of destroying and restoring the roads andplantings;
2. narrow spaces and roads limiting the usage of bigmachine;
3. the labor price rises fast in these years.
16• Running costs of the decentralized wastewater
treatment facilities
Direct running costelectricity

labortraffic

material

direct running cost (RMB/household/year)

350
300

17.49%

4.6%

250

5.59%
6.11%
1.40%

200
31.96%

30.92%

7.56%

150
100
50maintainThe ratio of thelabor cost of VTP
facilities is much
more than that ofthe OTP

54.53%
39.85%

Routing inspection cycle
 VTP: 10days
 OTP with Johkasou: 3months

0VTP

OTP

Total running cost
 OTP: 399 RMB/household/y VTP: 392 RMB/household/yUrgently to improve theconstruction quality of VTP
facilities17• Equivalent annual total cost （EATC）
Unit: RMB/household/y2816

2871

UTPVTP2334

 the EATC of OTP
is much less thanthe others
 the UPT’s is a littlesmaller than theVTP’sOTP

Life of Pipeline: 50 years
Life of treatment facilities: 30 years
The equivalent annual total cost
(EATC) is the cost per year of owningand operating an asset over its entire
lifespan with a giving discount rate.
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Conclusion and Proposal• The EATCs of UTP, VTP and OTP are respectively 2,816
RMB/household/year, 2,820 RMB/household/year and 2334
RMB/household/year. The EATC of OTP was much lower
than the others’.
– The construction cost of OTP using the Japanese household Johkasou wassignificantly lower than others. The high cost of the pipeline construction inexisting settlements is unbeneficial for choosing more concentrated sewage
patterns.
– the running and maintenance workload of the facilities using the Japanesehousehold Johkasou technology is comparably low. The building quality ofthe VTP facilities in China urgently needs to be improved.

• OTP should be the preferential sewage pattern in current
rural wastewater treatment in Changshu and in similar areasof China, and the technology of the Japanese householdJohkasou or other technologies with equivalent performance
should be adopted in engineering
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