Xây dựng các tiêu chí đánh giá và chỉ tiêu kinh tế kỹ thuật để đảm bảo hoạt động bền vững của nhà máy xử lý nước thải đô thị tt tiếng anh

 


 
MINISTRY OF EDUCATION AND TRAINING

Do Thi Minh Hanh

DEVELOPMENT OF EVALUATION CRITERIA AND
TECHNO-ECONOMIC CRITERIA TO ENSURE
SUSTAINABLE OPERATION OF URBAN WASTEWATER
TREATMENT PLANT

Major: Environmental Technology, Water and Wastewater
Treatment
Code: 9520320-2

SUMMARY OF DOCTORAL DISSERTATION

Hanoi, 2019



 


 
The study is completed at

Supervisor 1: Ass.Prof.Dr. Tran Duc Ha

Supervisor 2: Dr. Pham Tuan Hung

Opponent 1: Ass.Prof.Dr. Nguyen Hong Tien

Opponent 2: Dr. Le Van Long

Opponent 3: Ass.Prof.Dr. Do Khac Uan

The Dissertation shall be defensed prior to the Dissertation
Evaluation Committee (DEC) met at National University of
Civil Engineering
At.........o’clock dated......../...../......

Further study may be investigated at library of National University
of Civil Engineering


1


 
BACKGROUND
1. Rationale
Vietnam is characterized by theEast Asia’s 6th highest urban
population [25]. Fast urbanization speed in Vietnam is recorded with
forecast on additional one million of new urban residents per year.
As of 4 December 2018, Vietnam was the home of 819 cities,
including: 2 special cities namely Hanoi and Ho Chi Minh City, 19
cities of Grade I, 26 cities of grade II, 46 cities of grade III, 83 cities
of grade IV and 645 cities of grade V. By 2020, urban population

shall hit approximately 44 million persons, accounting for 45% of
urban population nationwide. By 2025, 1,000 cities shall be available
including 17 cities of grade I to special grade, 20 cities of grade II,
81 cities of grade III, 122 cities of grade IV and the remaining of city
grade V[30].
Meanwhile, the scope of water drainage and cleaning system service
is relatively restricted due to disqualified physical and technical
facilities both in terms of quantity and quality. New drainage culvert
system only satisfies 50-60% and 30-40% demand of population in
major cities and small and medium cities, respectively. The
constructed wastewater treatment plants (WWTPs) are not abundant
and ineffectively operated; hence, the treated urban wastewater
volume under the environmental standards is not significantly
recorded. Vietnam Water Supply and Sewage Association (2019)
revealed that, 37/63 localities were supported with WWTPs and 5
localities were provided with concentrated domestic WWTPs [16].
However, most of WWTPswere recorded with operation of less than
50% of designed capacity. Event some WWTPs which have been
constructed were not fully provided with wastewater for treatment.
One of root causes is that the difficulties in selecting wastewater
technology and connection are faced by the concentrated wastewater
drainage and treatment projects [11].
Currently, wastewater revenue is generated by applying a fee percent
against on all water consumers in accordance with the Decree No.
154/2016/ND-CP or drainage service charge under the Decree No.
80/2014/ND-CP. The Decree No. 154/2016/ND-CP on
environmental protection fee specifies that the maximum
Environmental protection fee for waste water must 10% of clean

2


 
water price that the drainage system management and operation
demand cannot be successfully satisfied. Drainage service charge
under the Decree No. 80/2014/ND-CP has been applied by some
cities to mobilize the contribution from service users, reducing the
pressure on the State budget. Drainage service charge applied for the
households is higher than the environmental fee and varied within
the range of VND 1,000 – VND 2,600 [34]. Although the drainage
service charge is high, it is still remarkably lower than that of
wastewater treatment price.
Actual operating costs must be funded by the local budget as
Operation and Maintenance (O&M) costs cannot be covered by
wastewater collection fees. In fact, expenditure for wastewater
system O&M is mainly relied on annual expenditure funded by the
Provincial/Municipal People's Committee through the Department of
Finance and allocated to the Department of Construction. Revenue of
Water Supply Company is originated from the water consumers.
Such revenue is held by the municipal or provincial authorities to
redistribute to the wastewater enterprises in accordance with the
approved annual budget.
In urban areas of Vietnam, there are only 46 WWTPs (as of the end
of 2019) but many of them are not stable and efficient for many
different reasons (although most them were just built during recent
10 years). Studies and assessments of this situation are very limited
and incomplete. Therefore, it is necessary to set up criteria to
evaluate the sustainable operation of those plants. According to the
evaluation criteria and facilitate the feasible solutions to ensure

WWTPs’ sustainable operation, the techno-economic criteria must be
setup.
Bac Ninh City'sWWTP is developed from KfW (Germany) loan
sources and has been put into operation since 2013. Upon 5 years of
operation, its great contribution on wastewater treatment and
improvement of Bac Ninh water environment has been made. In
order to ensure the reliability and applicability, collected data on Bac
Ninh WWTP management and operation is evaluated in accordance
with the proposed criteria and techno-economic indicators.
2. Objectives


3


 
-  
Design evaluation criteria for sustainable development of
urban WWTPs.
-  
Set up techno-economic criteria for sustainable development
of urban WWTPs.
-  
Apply the evaluation criteria and techno-economic criteria to
ensure the sustainable development of Bac Ninh WWTP.
3. Subjects and scope of the research
-  
Subjects of the research: Management, operation and
maintenance of urban WWTPs
-  

Scope of research: Urban WWTPs in Vietnam
4. Scientific basis of the thesis:

Through theoretical research on the sustainability of WWTP;
collection and analysis of data, consultation with experts on the
operation of the WWTPs to propose the criteria for evaluating the
sustainable operation of the WWTPs. Based on the criteria and the
importance of each of these criteria, formulate the economictechnicalindicators to ensure the sustainable operation of the
WWTPs. Having theeconomic-technical indicators to help the
operators to find out solutions to ensure the sustainable operation of
WWTPs is the practical meaning of the thesis.
5. Research methodology
According to the objectives, following research methodologies have
been applied:
-  
Survey and collection of data and documents on technoeconomic criteria when investment project is prepared and
management and operation of available urban WWTPs in Vietnam;
-  
Analysis and evaluation of techno-economic criteria of urban
WWTPs;
-  
Development of questionnaire and construction of experts
and technicians in urban wastewater treatment fields;
-  
Application of Analytic Hierarchy Process (AHP) method in
combination with expert consultation to analyze the evaluation
criteria and develop the techno-economic criteria to ensure
sustainable operation of urban WWTPs.
In order to successfully fulfill the research objectives, the concerned
contents and methods are summarized in Figure 0.1.

4


 
General study on urban
wastewater and sustainable
operation of urban WWTPs

(1)   Wastewater treatment capacity and efficiency
(2)   Appropriateness of wastewater treatment
technology with local conditions
(3)   O&M costs
(4)   Operating conditions of works and equipment
(5)   Safety and environmental friendliness
(6)   Adaptability with adverse impacts of climate
changes and input factor changes

Technology criteria
group:
- Wastewater capacity
and mode
- Wastewater
treatment
performance
O&M criteria group:
-Appropriateness with
local context
-Adaptability with

climate change
- Safety and environmental
friendliness

Legislation and
management criteria
group:
-Operation
management
mechanism of WWTP
operator
- Management
Financial criteria
group:
- Water drainage
service charge
-Income of WWTPs
-O&M cost savings

Data collection, literature
review and analysis and
evaluation

Selection of proper
evaluation criteria groups for
urban WWTPs’
sustainability

Quantitative analysis and
evaluation in combination

with expert consultation

Determine weights and
priorities of evaluation
criteria groups for urban
WWTPs’ sustainability

Analyze by AHP in
combination with expert
consultation (supported by
Expert Choice 11 Software)

Design the technoeconomic criteria groups to
ensure sustainable operation
of urban WWTPs

Analyze by AHP (supported
by Expert Choice 11
Software)

Discuss the main findings
and propose the solutions
on enhancing the
sustainable operation of
urban WWTPs

Evaluate and adjust the main
findings by data collected at
BacNinh City’s WWTP

Figure 0.1 Summary of research contents and method applied herein

6. New implications
-  
Design evaluation criteria for sustainable development of urban
WWTPs in Vietnam;
-  
Set up techno-economic criteria for sustainable development of
urban WWTPs in Vietnam;
-  
Apply AHP method in combination with expert consultation to
propose and determine weights of sustainability evaluation criteria in
operation of WWTPs.
-  
Propose the possible solutions for sustainable operation of Bac
Ninh City’s WWTP in accordance with the techno-economic criteria.
7. Structure
In addition to preface, conclusions, recommendations, appendix
and list of publications, the study comprises of 3 chapters:
Chapter 1: Overview (40 pages)
Chapter 2: Scientific basis and research methodology (30 pages)
Chapter 3: Development of evaluation criteria for sustainable
development of urban WWTPs in Vietnam (55 pages)


5


 
CHAPTER 1: OVERVIEW

1.1.  
Characteristics of urban wastewater and operation of
concentrated urban wastewater treatment plants
1.1.1.   Components and properties of urban wastewater
Urban wastewater refers to wastewater originated from cities, mixed
with domestic and production wastewater from industrial activities
and services in the city and runoff. Vietnam urban wastewater is
characterized by 67-85% [2] of domestic wastewater. Domestic
wastewater volume in developing countries is estimated to be equal
to 80% of water volume provided in the regions with normal
development level and 90% of sharply developed areas [9].
1.1.2.   Urban drainage and treatment in concentrated urban
wastewater treatment plants
3 urban drainage models are currently available, concretely:
Concentrated wastewater treatment drainage; distributed wastewater
treatment and drainage and onsite wastewater treatment.
1.2.  
Evaluation of existing condition of urban WWTPs in
Vietnam
1.2.1.   Existing condition of urban WWTPs in Vietnam
Number of constructed wastewater treatment plants (WWTPs) is not
abundant and ineffective; hence, the treated urban wastewater volume
under the environmental standards is not significantly recorded.
Vietnam Water Supply and Sewage Association, 2018, revealed that
only 41 urban WWTPs are put into operation with total capacity of
approximately 950,000 m3/day and 28 other WWTPs are being
constructed. However, most of WWTPs are recorded with operation of
less than 50% of designed capacity. Event some WWTPs which have
been constructed are not provided with wastewater for treatment.
1.2.2.   Evaluation of operating performance of available WWTPs

a) WWTPs’ business performance
Concentrated wastewater treatment and drainage projects are faced with
a myriad of difficulties in technology selection, works design and
construction quality, appraisal procedures, household connection
percent, financial affairs, operating capacity, local monitoring and
control, environment monitoring during the project performance, etc.
With low input organic concentration, the urban WWTPs should be


6


 
applied with proper technologies at lower cost, facilitating the future
scalability if the wastewater characteristics or input wastewater flow rate
is improved. Energy savings or efficiency, natural resource salvage from
waste sludge or post-treatment wastewater reuse are not significantly
focused and prioritized.
b) Efficiency of waste sludge and odor treatment
Some projects only focus on wastewater treatment, rather than waste
sludge and odor treatment. The sludge treatment technologies, mainly
including dehydration and waste sludge drying, are not stable. Sludge
treatment is not proper, resulting in bad odor in the area and entire plant.
1.3.  
Root causes for unsustainable operation of urban WWTPs
1.3.1.   Legislative causes
a.   Legal documents
Water resource protection is specified in the Law on Environmental
Protection, Law on Water Resources. Legal implementation guidelines
include: The Decree No. 80/2014/ND-CP on wastewater drainage and

treatment and the Decree No. 25/2013/ND-CP on environmental
protection fee for wastewater. However, overlap and conflicts are still
found among such legal documents, especially water drainage and
environmental protection service charges.
Currently, the codes on urban wastewater discharging to surface water
are still unavailable. That is why the parameter values in QCVN
40:2011/BTNMT - National Technical Regulation on Industrial
Wastewater or QCVN 14:2008/BTNMT - National Technical
Regulation on domestic wastewater (applied for small scale subjects not
through concentrated drainage system that is directly discharged into the
external receiving environment) are applied as the hygiene conditions to
discharge the urban wastewater to the receipt source.
b.   Mechanisms and policies of management, investment and
operation of drainage system and WWTPs
Implementation of drainage-related mechanisms and policies is found
with some restrictions as follows: Delay implementation, confused
application and shortcomings due to restrictions in human resources as
well as capacity and qualifications of officials from local
regulators;improper concern on drainage, urban and industrial park
wastewater treatment found in many local authorities.
1.3.2.   Management of assets and human resources


7


 
a. Asset management and operation of drainage system and urban
wastewater treatment
Owners of wastewater treatment assets and operation management units

have been specified in the Decree No. 80/2014/ND-CP concerning the
investment activities, management, operation and supply of drainage,
wastewater collection and treatment services in areas. However, Project
Management Units (PMUs) has been still established in the drainage
management enterprises.
b. Human resources
The world cutting-edge technologies in drainage and wastewater
treatment have been approached and applied in Vietnam; however, the
concerned in-depth training centers are unavailable. The training
institutions are not fully provided with physical facilities such as
lecturers, labs, practice workshop, libraries, etc. Water supply &
drainage service providers and the training institutions are not well
connected.
c. Communications and community education
Propaganda, education and dissemination of laws on environmental
protection to the population community are relatively restricted;
enforcement of policies and laws on environmental protection is not
well observed, valid and effective. Benefits of raising the community
awareness on launching wastewater management activities are not
clearly recognized by the drainage and wastewater treatment companies.
1.3.3.   O&M costs
Actual operating costs must be funded by the local budget as Operation
and Maintenance (O&M) costs cannot be covered by wastewater
collection fees. O&M costs of urban WWTPs are largely depended on
treatment capacity and technology as specified in Decision No. 451:
2015 / QD-BXD. In fact, expenditure for wastewater system O&M is
mainly relied on annual expenditure funded by the Provincial/Municipal
People's Committee through the Department of Finance and allocated to
the Department of Construction. The wastewater fee is found in the
water consumer’s invoices. Water supply revenue from such fee is

annually paid to the municipal or provincial budget to redistribute to the
drainage enterprises.
1.3.4.   Technology and technical issues
a. Drainage and wastewater treatment technology
Consistent criteria and implementation procedures have not been
available to evaluate and select the drainage and wastewater treatment


8


 
technology for cities, industrial parks and hospitals. Feasible
technologies such as: combination of concentrated and distributed
wastewater collection and treatment, gradually upgrading the posttreatment water quality, ensuring the solvency of service users, etc., are
not the top priorities of consultant and decision makers.
b. Technical issues
The above analysis unveiled that: Technical and financial conditions for
study and launch of wastewater drainage and treatment technology, etc.,
are relatively restricted; it lacks the environmental pollution treatment
solutions and technologies suitable with the regional and local
conditions or at river basins as well as good response to the climate
change and seawater rise in drainage and wastewater treatment activities
is not found.
1.4.  
Existing conditions on sustainable operation of the world’s
WWTPs
1.4.1.   Existing conditions on sustainable operation of WWTPs in
some countries in the world
Root causes of WWTPs’ ineffective operation may include: Degradation

of infrastructure, inactive pumping station, leakage pipeline and
malfunction of wastewater treatment works. Many plants are also left
(or not operated) due to insufficient O&M expenditure or technical
capacity to fulfill the tasks, especially at local level and upon control by
the restricted management systems.
1.4.2.   Overview about the financial management policies and
mechanisms to ensure the WWTPs’ sustainable operation in the world
It is not simple to strengthen the wastewater management and operation
performance and some problems (such as water discharge management,
financial aspects, etc.) must be completely handled.
1.4.3.   Existing conditions on evaluating the sustainable operation of
the world’s WWTPs
1.4.3.1.   Evaluation of Greek WWTP’s sustainable operation
The evaluation of WWTPs’ sustainable operation aims to set up the
methods and apply such methods to evaluate 14 Greek-based WWTPs in
the context that it not only involves in compliance but also specific
aspects related to other issues such as environment, technique,
economics and social affairs and then each plant's sustainability may be
evaluated[44].


9


 
With reference to the questions, the quality or quantity consultancy table
given for each criterion is completed. Results of such criteria evaluation
are used for subsequent standardization and valid as the reference
standard in the WWTP system.
1.4.3.2.   Evaluation of wastewater treatment sustainability in

Sweden
In order to illustrate the sustainability of wastewater drainage and
treatment system, three various scenarios are used with three
comparative examples from three different countries: Sweden, South
Africa and Mexico. Then it is evaluated by a comprehensive comparison
methodology [72].
Upon comparison among Sweden, South Africa and Mexico, it is found
that various systems are evaluated to have advantages and disadvantages
in its respective settings. The evaluation results are also unveiled that the
evaluation results are depended on the context of such three countries.
Conclusions of Chapter 1:
Intensive investments from various financial resources have been
launched by Vietnamese Government in the fields of water drainage and
environmental sanitation fields for the cities since many years.
However, due to various reasons, including the technical reasons such as
improper wastewater treatment technology, investment indicators of
water drainage system are asynchronous and characterized by the nonguaranteed operation qualification, low wastewater connection percent,
etc. Such factors make the invested wastewater treatment and drainage
systems operate ineffectively. Adverse impacts of climate changes are
increasingly clear for Vietnam and urban wastewater drainage and
treatment is one of the activities to be seriously affected.
Main factors to ensure a sustainable operation of an urban WWTP
include treatment technology and proper operation and management.
Such fitness must be evaluated in accordance with the criteria related to
the technical, environmental, socio-economic factors. Therefore, such
criteria must be analyzed, selected and quantified in combination with
the consultation of experts and managers, etc., who are extensively
experienced in the fields of wastewater drainage and treatment.
The experience of countries in the world unveiled that evaluation of
WWTP’s sustainability must have a panorama on considering the

criteria in any various aspects such as economics, techniques,
environment and socio-economics and the criteria significance must be


10


 
determined, corresponding to the various environment and economic
viewpoints, etc.

2.1.  

CHAPTER 2: SCIENTIFIC BASIS AND RESEARCH
METHODOLOGY
Scientific basis to develop the evaluation criteria and
indicators, ensuring the sustainability of urban WWTPs

2.1.1.   General concept
Concepts: Sustainability; criteria; indicators; techno-economic criteria,
criteria set.
2.1.2.   Sustainable operations of concentrated urban Wastewater
Treatment Plant (WWTP)
2.1.2.1.   Sustainability of urban WWTP
A proper WWTP for sustainable development is supported by the proper
investment and operation expenses. Its long-term operation is
technically and legally guaranteed as well as its pollution treatment
performance is highly appreciated and accepted by the community.
2.1.2.2.   Sustainability of urban concentrated WWTP in the context of
climate changes

The technical criteria’ adaptability with the climate change impacts is
demonstrated by the selected wastewater treatment technology line
which may prevent the salt water intrusion upon tide and heavy rains in
the coastal cities. Works arranged in the WWTPs must process and well
adapt with the BOD and salt contents in the wastewater and act against
the high material oxidization, etc. WWTPs must be located at high
terrain. Such plants must well operate in the high salt content conditions.
WWTPs must be able to retain water for a long time.
2.1.3.   Evaluation criteria of urban WWTP’s sustainability
Evaluation criteria of wastewater treatment technologies are proposed in
Table 2.2 below:
Table 2.2: List of evaluation criteria for urban WWTP’s sustainability
No.
Criteria group
Criteria
1
Wastewater treatment The Plant’s actual capacity must ensure
capacity
and to cover project site
efficiency
Treatment must be qualified with the
environmental standards for basic


11


 

2

O&M costs

3

Adaptability
of
wastewater
technology with local
context

4

Stable
operating
conditions of works
and equipment

5

Adaptability with the
adverse impacts of
climate changes and
input factor changes

contaminant indicators in domestic
wastewater (SS, BOD, TN, TP,
coliform, etc.)
Treatment must be qualified with the
environmental standards for some

pollution criteria available in the
production and service wastewater,
etc., in the project site
O&M costs are low
Energy savings and efficiency and
energy recovery of equipment and
works are feasible
Treatment costs are saved thanks to
recovery and reuse of wastewater,
waste sludge and biogas
Selected
wastewater
treatment
technology is suitable with the local
natural conditions and load bearing
capacity of receiving source
The technology is advanced and
suitable with the available science and
technology conditions in the area
Operation of works and equipment is
not complicated
Equipment and its components are
easily replaced
Works operation is qualified with the
environmental requirements
Treatment efficiency is ensured in the
conditions that the wastewater is
characterized by salt concentration and
sudden high temperature
Treatment efficiency is ensured in the

conditions that the input wastewater is
characterized by varied contents of SS,
BOD and other pollution criteria
It is possible to store water when the
input wastewater flow rate is increased


12


 
6

Safety
environmental
friendliness

and

for long time due to storm and rain.
WWTPs are located far from the
residential
areas
and
sensitive
ecosystem zone, making use of natural
conditions to enhance the wastewater
cleaning, restricting the bad odor and
noise, etc.
Cleaning conditions and working

conditions in WWTPs are qualified
with the standards promulgated by the
Ministry of Health

2.1.4.   Techno-economic criteria to ensure the urban WWTP’s
sustainability
According to 6 selected criteria set and application of proper analytic
methods, techno-economic criteria sets may be designed and
developed to ensure the operation sustainability and stability of a
WWTP. The proposed techno-economic criteria are shown in Table
2.3:
Table 2.3: List of techno-economic criteria to ensure sustainable
operation of WWTP
No.

Techno-economic
criteria group

Techno-economic criteria

1

Technology

Wastewater capacity and mode

2

O&M

Adaptability with local conditions
Adaptability with climate changes
Safety
and
friendliness

3

Legislation
management

and

environmental

Management mode on operation of
WWTP operator
Management
Asset management


13


 
4

Finance

Water drainage service charge

Income of WWTPs
Possibility of O&M cost savings

Each of criteria group may be based on various criteria. The various
criteria groups may share some indicators, creating an interwoven
matrix demonstrated in Figure 2.4.
Urban WWTP’s sustainable operation

Criteria group 1
Wastewater
treatment capacity
and efficiency

Technology

Criteria group 2
O&M costs

Finance

Criteria group 3
Adaptability of
wastewater treatment
technology with local
conditions

Criteria group 4
Stable operating
conditions of works
and equipment

Criteria group 5
Safety and
environmental
friendliness

Legislation and
management

Criteria group 6
Adaptability with
adverse impacts of
climate changes and
input factor changes

O&M

Techno-economic criteria for urban WWTP’s sustainable operation
Figure 2.4: Relation between criteria groups and techno-economic criteria groups

2.2.  
Research methodology to design the techno-economic
criteria and indicators
2.2.1.   Theoretical analysis and synthesis method
This method aims to study various literatures on existing conditions
of urban WWTPs and related jurisdictions.
2.2.2.   Field trip survey method
The method aims to obtain the data on WWTPs to ensure the
evaluation criteria sets and techno-economic indicators to ensure the
sustainable development concentrated urban WWTPs, nationwide.

2.2.3.   Weighting method of criteria
The Analytic Hierarchy Process (AHP) method has been applied to
determine the weights of evaluation criteria to summarize the
sustainable development of WWTPs as AHP is a technique to decide


14


 
and arrange the evaluation criteria by significance. Thanks to that a
most smart decision may be found.
2.2.4.   Expert consultation method
In this study, the questionnaires are delivered to two expert groups,
namely:
-   Group 1: Science and technology official with qualification in
water supply & drainage, environment engineering and technical
infrastructure at universities, research institutions, etc.
-   Group 2: Managers of enterprises involving in water supply &
drainage, environment engineering, infrastructure engineering, etc.
Expert consultation aims to evaluate the significance of indicator
criteria to determine AHP weights for the criteria. Comparison score
for significance of AHP-based criteria pairs is taken from average
score of consultants: Each expert has determined the significance for
criteria. Next, it is required to study and summarize the significance
of each criterion and determine the weights.
Evaluation criteria of wastewater treatment technology are often
quantified by weights or scores from the consultancy data processing
results shown in Appendix 3.4.
2.2.5.   Analytic Hierarchy Process (AHP) method

Analytic Hierarchy Process (AHP) method is a method used to
calculate the weights applied for multi-criteria decision making
problems. Quantification comparison is initiated by using the
comparison pairs of solutions in accordance with its relative
efficiency against the applied criteria to select a proper solution.
AHP was studied and developed in 1980s by Saaty [78].
Expert choice software facilitates to determine the weights for
evaluation criteria of urban WWTP’s sustainability:
Step 1: Create tree model (create from criteria group and supply the
branches, i.e., criteria)
Step 2: Enter the value to compare the significance of criteria groups
demonstrated in Table 3.1 and Appendix 3.5.
Step 3: Enter the value to compare the significance of criteria
demonstrated in Table 3.3
Step 4: After data is processed by Expert Choice Software, the
obtained results are weights, demonstrating the significance level of


15


 
the criteria groups and criteria (demonstrated in Table 3.4 and
Appendix 3.6).
Conclusions of Chapter 2
Chapter 2 has successfully setup the scientific basis, analyzed and
selected the proper research methodologies. Requirements on urban
WWTP’s sustainability must be set forth to design and develop the
evaluation criteria as well as techno-economic indicators to ensure
the plant’s good operation.

The study applies the theoretical analysis and synthesis method,
summarizes the literature review, determines the weights, and
analyzes AHP and expert consultation method. Such methods
mutually support each other and well adapt to determine the weights
of criteria.
Expert method uses the intelligence, exploit the evaluation viewpoint
of high qualified experts to review and judge a problem, a scientific
event, particularly sustainability in WWTPs’ operation to give out
the advises which are well matched with the practice on such
sustainability activities.
The Analytic Hierarchy Process (AHP) method has been applied to
determine the weights of evaluation criteria to summarize the
sustainable development of WWTPs as AHP is a technique to decide
and arrange the evaluation criteria by significance. Thanks to that a
most smart decision may be found.


16


 
CHAPTER 3: DESIGN EVALUATION CRITERIA AND
TECHNO-ECONOMIC CRITERIA TO ENSURE URBAN
WWTP’SSUSTAINABLE OPERATION
3.1.   Design evaluation criteria for sustainable development of
WWTPs
Upon determination of evaluation criteria for WWTP’s sustainable
operation, the consultation table has been designed in the form
specified in Appendix 3.1:
- Evaluate sustainable operation of WWTPs by 6 criteria groups.

New WWTPs are recorded with sustainable operation if total score
of 70-100 for 6 criteria groups is agreed by the experts: Total score
of criteria in column “Max score value” and “Min score value” is
100 and 70, respectively.
- The main findings from the MoC-level study “Investigation and
proposal of factors to select the proper urban wastewater treatment
technology for regions in Vietnam” launched by Ass.Prof.Dr Tran
Duc Ha [9] unveiled that, Min value of 65 is technologically taken.
In addition to the technology factors, other aspects such as economic
efficiency, adaptability with climate changes, etc., have been
considered hereof. The min score of sustainable WWTP is 70 in
accordance with the expert consultation results. Such 70 score
threshold is used as the minimum threshold to evaluate the
sustainable WWTPs.
Score of expert-based criteria is tabled in Table 3.4: Contents of this
appendix demonstrate the mean of Max and Min scores,
corresponding to each criterion.
Within the contents hereof, the evaluation criteria for the urban
WTTP’s sustainability is based on total score of criteria higher or
equal to 70 scores (Min scores). Therefore, weights of Min score
criteria of consultation table are determined.
Calculations of AHP-based evaluation model are supported by
Expert choice 11.0. Results are shown in Table 3.4 (table results are
converted with weights multiplied with 100%):


17


 

Table 3.4 Weights of criteria (determined by Expert choice 11
Software)
Weights
Weight
among
among
Criteria
criteria
criteria
group (%)
set (%)
1. Wastewater treatment capacity and
100
33.7
efficient
The Plant’s actual capacity must
37.2
12.5
ensure to cover project site
Treatment must be qualified with the
39.4
13.3
environmental standards for basic
contaminant indicators in domestic
wastewater (SS, BOD, TN, TP,
coliform, etc.)
Treatment must be qualified with the
23.4
7.9
environmental standards for some

pollution criteria available in the
production and service wastewater,
etc., in the project site
2
Appropriateness
of
wastewater
100
15.2
treatment technology with local
conditions
Selected
wastewater
treatment
46.3
7.0
technology is suitable with the local
natural conditions and load bearing
capacity of receiving source
The technology is advanced and
28.0
4.3
suitable with the available science
and technology conditions in the area
Wastewater treatment technology
25.7
3.9
must be well matched with the local
management and operation capacity
3. O&M costs

100
20.9
O&M costs are low
53.2
11.1
Energy savings and efficiency and
25.7
5.4
energy recovery of equipment and
works are feasible


18


 
Treatment costs are saved thanks to
recovery and reuse of wastewater,
waste sludge and biogas
4. Stable operating conditions of works
and equipment
Operation of works and equipment is
not complicated
Equipment and its components are
easily replaced
5. Adaptability with adverse impacts of
climate changes and input factor changes
Treatment efficiency is ensured in the
conditions that the wastewater is
characterized by salt concentration

and sudden high temperature
Treatment efficiency is ensured in the
conditions that the input wastewater
is characterized by varied contents of
SS, BOD and other pollution criteria
It is possible to store water when the
input wastewater flow rate is
increased for long time due to storm
and rain.
6. Safety and environmental friendliness
Wastewater treatment works do not
cause
bad
odor,
surrounding
environmental pollution, noise, less
incidents and wastewater leakage,
reducing the soil, underground water
source and surface water pollution
risks of surroundings
WWTPs are located far from the
residential areas and sensitive
ecosystem zone, making use of
natural conditions to enhance the
wastewater cleaning, restricting the
bad odor and noise, etc.
Cleaning conditions and working

21.1

4.4

100

12.5

41.7

5.2

32.8

4.1

100

7.7

39.3

3.05

39.3

3.05

21.4

1.6

100
49.8

10
5.0

30.2

3.0

20.0

2.0


19


 
conditions in WWTPs are qualified
with the standards promulgated by
the Ministry of Health

Priority sequence of criteria group is determined as follows:
Wastewater
treatment
capacity
and
efficiency>O&M
costs>Suitability of wastewater treatment technology with the local

conditions> Operating conditions of works and environment >
Environmental friendliness and safety > Adaptability with adverse
impacts of climate change and input factor changes.
Two criteria groups of Wastewater Treatment Capacity and
Efficiency and O&M Costs have the highest significance level of
33.7 and 20.9, respectively and this is completely suitable with the
practice. Such two criteria groups are essential and necessary for the
wastewater treatment plants. Concretely, the system must be properly
and effectively functioned (Criteria group of Wastewater Treatment
Capacity and Efficiency) and the system must be qualified with the
economic criteria (O&M cost criteria group) such as investment
expenditure, O&M costs, etc.
3.2.   Development of techno-economic criteria to ensure
sustainable operation of urban wastewater treatment plant
3.2.1.   Technology criteria group
For the technology criteria grop, the treatment efficiency criteria is
the most important one. Moreover, in order to evaluate the best
performance of WWTP’s technology, criteria on appropriateness of
wastewater treatment technologies and local conditions, good adopt
and adapt with climate changes as well as criteria on impacts of
WWTPs on surrounding environment.
3.2.1.1.  
Water discharge capacity and mode criteria
Discharging mode is another basic factor related to calculation of
water drainage network and wastewater works. Urban wastewater
discharging mode is depended on water consumption mode and
characterized by non-regulating water discharge coefficient Kch. Kch
refers to the ratio of discharge flow rate of the highest water
consumption hours of the highest water consumption day (qh,max) and

20


 
wastewater flow rate of average water consumption hours of average
water consumption day (qh,tb).
3.2.1.2.  
Wastewater Treatment Efficiency Criteria
Wastewater treatment requirements (level): Treatment is qualified
with level A of QCVN 40:2011/BTNMT or QCVN
14:2008/BTNMT. Currently, the wastewater pollution is mainly
evaluated by 4 parameters as follows: SS; BOD5; TN, TP; Coliform
According to QCVN 40-MT:2011/BTNMT: Consumers have
domestic and urban wastewater volume greater than or equal to 1500
(one thousand and five hundred) cubic meter/day and night (m3/24h):
Maximum allowable value of pollution parameters in domestic and
urban wastewater upon discharge into the wastewater receiving
source is calculated by following formula:
Cmax = C x Kq x Kf
3.2.2.   O&M criteria group
3.2.2.1.  
Suitability with the local conditions:
Selected wastewater treatment technology must be well matched
with the urban conditions such as natural characteristics (terrains,
engineering geology, hydro-geology, climate and weather, etc.);
socio-economic conditions (urban level, land use conditions and
structure); urban development planning characteristics; the project’s
financial capacity, etc.
3.2.2.2.  

Adaptability with climate change
In order to guarantee sustainable operation of urban WWTPs, the
climate change-related criteria must be considered, namely:
-   Treatment efficiency in the conditions that the wastewater is
characterized by salt concentration and sudden high temperature.
-   Treatment efficiency in the conditions that the input wastewater
is found with contents of SS, BOD and other variable pollution
criteria.
-   Water storage capacity for a long time due to increase in storm,
flood and works (regulating tanks, wastewater stabilizing reservoir,
etc.)
3.2.2.3.  
Environmental friendly safety


21


 
When efficiency of urban wastewater treatment production line is
evaluated, it is required to take care about issues such as bad odor
restriction and treatment capacity, generated waste sludge volume
and sludge treatment method, etc.
3.2.3.   Regulation and management criteria group
3.2.3.1.  Criteria on WWTP operator management mechanism
The enterprise form of WWTP operator is mainly single member
liability limited company or Joint Stock Company operating under
the Law on Enterprises and managing the water drainage assets and
wastewater treatment in accordance with the contract signed with the
Owner under the Decree No.: 80/2014/ND-CP.

3.2.3.2.  

Management and operation organization

Corresponding to each available wastewater treatment enterprise
form of Single Member Liability Limited Company or Joint Stock
Company, the management apparatus of wastewater treatment
enterprises is generally structured in accordance with the aforesaid
diagrams in Figure 3.1, Figure 3.3 and Figure 3.3.
3.2.3.3.  
Asset Management
According to the Decree No. 80/2014/ND-CP of the Government
dated 6 August 2014 on water drainage and wastewater treatment,
for urban water drainage system, the concentrated rural residential
area is invested by the State budget. The water drainage unit
selection is complied with the applicable legal regulations on supply
of public products and services. The water drainage unit must be
supported by the necessary manpower, equipment and technical
facilities to fulfill the requirements and tasks of rainwater and
wastewater drainage system operation and management. The
drainage unit shall own the water drainage system selected in the
area under its management. The drainage system management and
operation contract must be made and entered by and between the
owner and unit assigned to manage and operate the water drainage
system. This is the legal document is legally recognized.
3.2.4.   Financial criteria group
3.2.4.1.   Water drainage service charge indicator


22

 
O&M costs of WWTPs are determined in accordance with the
Circular No. 13/2018/TT-BXD dated 27 December 2018
In addition to O&M costs, the service charge also includes other
expenses: Fundamental construction investment expenses; redevelopment
expenses;
external
socio-economic
factors;
environmental factors and climate changes.
Wastewater treatment service charge is setup from O&M costs in
accordance with the principles of Comprehensive Management of
Water Resources as illustrated in Figure 3.5 below.
Environmental factors, climate changes
External socio-economic factors

ECONOMIC
PRICE OF
WATER

Re-development expenses
Fundamental construction
investment

FULL
PRICE OF
WATER

QUALIFIED
WATER
PRICE

O&M costs

3.2.4.2.  

Income of WWTPs

In order to obtain sustainable operation of WWTPs, the plant income
must be collected in accordance with the water drainage service
charge from:
-   Expenditures from wastewater fees
-   Expenditures from the State budget
-   Expenditures from grants: ODA of various countries, WB,
ADB, JICA, etc.
3.2.4.3.   O&M cost savings
Annual expenses for urban wastewater treatment are very high;
meanwhile a large amount of post-treatment wastewater and waste
sludge may be reused. On the other hand, by various technical
solutions, it is possible to save the energy during equipment
operation. In order to reduce the O&M costs for urban WWTPs, it is
possible to minimize the power consumption of equipment, recover
and reuse the wastewater, waste sludge and formed biogas, etc.


23

 
3.3.   Application of techno-economic criteria and indicators to
ensure the operation sustainability of Bac Ninh City’s WWTP
3.3.1.  Description of water drainage system and Bac Ninh City’s
WWTP
Bac Ninh City’s WWTP is constructed at Kim Chau commune, Bac
Ninh City with capacity of: 17,500 m3/day and night (by 2020), its
construction area is 3 ha, commencement year was 2013. It is
recognized as a common water drainage system supported by
innovative SBR technology.
The plant is designed to ensure that the post-treatment wastewater
quality is qualified with Type B of QCVN 40:2011/BTNMT.
On 25 September 2015, the People’s Committee of Bac Ninh
promulgated the Decision No. 372/QD-UBND on establishing Bac
Ninh Sewerage and Wastewater Treatment Co., Ltd with 100% State
own capital under the ownership of the People’s Committee of Bac
Ninh.
On 3 December 2015, the People’s Committee of Bac Ninh
promulgated the Decision No. 500/QD-UBND on equitiztion of Bac
Ninh Sewerage and Wastewater Treatment Co., Ltd. Accordingly,
Phu Dien Join Stock Company held the shareholding of 65%.
3.3.2.   Evaluation of operation sustainability of Bac Ninh
Wastewater Treatment Plant
In addition to analyze the operation advantages and disadvantages of
Bac Ninh WWTP in accordance with the evaluation criteria using
respective weights, the expert method is applied through consultation
table on plant scoring (consultation table is described in Appendix
3.8). Scoring each evaluation criteria of WWTP’s sustainable
operation is shown as follows:
- Expert’s score with 1-100 scale for each criterion

- If wastewater treatment plant’s criteria are qualified, score of such
criteria shall be determined within the range of 70-100 scores.
- If wastewater treatment plant’s criteria are disqualified, score of
such criteria shall be <70 scores.
- Convertible score for evaluation = Weight x Expert Score/100
- Score for sustainability evaluation is Total convertible score of
Wastewater Treatment Plant