THE CURRENT STATE OF WATER SUPPLY AND … · drainage systems inside the civil buildings in ... Water supply and drainage systems inside ... than the standards for construction of

THE UNIVERSITY OF DANANG

UNIVERSITY OF SCIENCE AND TECHNOLOGY

THE CURRENT STATE OF WATER SUPPLY

AND DRAINAGE SYSTEMS INSIDE THE

CIVIL BUILDINGS IN DANANG CITY

Mai Thi Thuy Duong

Nguyen Lan Phuong

Faculty of Environment

KICK-OFF SYMPOSIUM ON “REDUCING GHG THROUGH WATER SMART LIFESTYLE IN DA NANG, VIETNAM”

Da Nang University of Technology, November 18th 2015

CONTENTS

I. OBJECTIVES OF THE STUDY

III. RESULTS

VI. CONCLUSIONS AND RECOMMENDATIONS

II. SUBJECTS AND SCOPE OF THE STUDY

I. OBJECTIVES, SUBJECTS AND SCOPE

OF THE STUDY

a. Objectives

- Assessing the current state of water supply and

drainage systems inside the civil buildings in Danang City.

- Proposing efficient water use plans and management.

b. Subjects

Water supply and drainage systems inside the civil

buildings.

c. Scope of the study

Water supply and drainage systems in households and

public buildings (Schools, hospitals, administrative offices,

apartments) in Da Nang city.

III. RESULTSWATER SUPPLY SYSTEM

A. HOUSEHOLDS

1. Source of Water Supplies

57.5

2.5

40

28.3

1556.7

90

10

40

60

71.9

15.6

12.5

77.3

22.7

83.4

3.3

13.3

62.74.5

32.8

Hoa Vang

Lien Chieu

Son Tra

Ngu Hanh Son

Thanh Khe

Hai Chau

Cam Le

2. Water appliances

Comments:

- The majority of households equipped with showers for bathing - making up 77.0%.

The greatest amount of households who utilize the most of water appliances occurs in

Hai Chau District, while the lowest in Hoa Vang.

III. RESULTS

Local

Tub use and

hot water

supply

Shower use,

Flush toilet

Tap,

Flush

toilet

Only taps

Son Tra% 1.4 71.7 24.0 2.9

l/person/day 137.4 141.2 122.6 116.5

Lien Chieu% 1.7 83.3 15.0

l/person/day 257 154 90.7

Hai Chau% 6.7 85.0 8.3

l/person/day 294.5 161.3 159.5

Hoa Vang% 55.0 28.3 16.7

l/person/day 130.2 127.5 32.6

Ngu H Son% 87.5 12.5

l/person/day 141.3 65

Thanh Khe% 2.7 81.3 16.0

l/person/day 313 152 146.7

Cam Le% 83.3 16.7

l/person/day 167 130.8

Whole city% 2.1 77.0 17.8 3.1

l/person/day 268 150 123.8 46.8

TCVN

4513-1988 l/person/day 350-400 150-200 100-150 80-100

3. Water use level of appliances

III. RESULTS

3. Water use level of appliances

Comments

-Average water use per person (l/person/day) proportional to the level of use of

appliances.

-The actual average water use per person is less than TCVN 4513-1988 because of

saving habits of people on daily water use.

III. RESULTS

4. Water use level per person

Local (L/person/day)

Son Tra 135.9

Lien Chieu 155

Hai Chau 164

Hoa Vang 126

Ngu Hanh Son 132

Thanh Khe 151

Cam Le 161

Whole city 146

Comments:

The average water use per person counted on the whole city is 146

(l/person/day), less than the target (180 l/person/day) and smaller than

standard TCXD 33-2006 (200 l/person/day). This happens because of:

- The low level of water appliances

- Habits and ways of using water

III. RESULTS

5. Diagram of water supply

Comments:

- Water supply system with water tanks on the roof is common (48.2%) as most of

houses are with 2-3 storeys, suitable to the current state of the water supply system of

the city where the water pressure can only be maintained on supply pipe about from 5-

27 meters. The system is simple, low cost, safe water supply.

- Map pump - water tanks are used more (23.5%) => Network pressure drops,

affecting the use water of objects around

III. RESULTS

20.06.7 8.3

63.346.9

21.3 24.1

42.558.3 61.7

25.0

15.650.7

83.348.2

25.035.0 26.7

11.7

34.4 18.7

16.723.5

12.53.3 3.1 9.3 4.2

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Bể chứa+Bơm+Két

nướcBơm+ Két nước

Két nước

Đơn giản

Storage tank +

Pum +Water tank

Pum + Water tank

Water tank

Simple

B. PUBLIC BUILDINGS

1. Source of supply water

Comments:

- 100% of public facilities use tap water as these facilities demand high

amount of water, stable and hygienic water supply.

- Some hospitals, schools having groundwater as an additional water supply

for irrigation needs, sanitation because this type of source has been using

for a long time.

III. RESULTSWATER SUPPY SYSTEM

67.076.2 78.0

100.0 100.0

33.023.8 22.0

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Hospital School Offices Apartment Hotel

Both

Tap water

2. Water use

Comments:

- Most of the buildings are having less average water use per person per day

than the standards for construction of water supply TCVN 4513: 1988 as:

+ Sanitary ware not fully equipped, simple.

+ Hygiene of toilets of public works is poor.

- For Administrative offices big amount of water used as water is also used by

the visitors. There is still a difficulty for determining the number of visitors.

Building UnitAverage water

use

TCVN 4513:1988

(l/person/day)

Hospital l/person/day 158.7 250-300

School l/person/day 7.73 15-20

Nursery school l/person/day 57.24 75

Administrative offices l/person/day 23.5 10-15

Apartment l/person/day 60÷130 100-120

III. RESULTS

3. Diagram of water supply

Comments: Most of them are using Storage tank – Pum – Tank,

ensure continuous water supply, suitable with the requirements of

work pressure.

III. RESULTS

Tank

Storage tank

DRAINAGE SYSTEM

1. Drainage rain water system

Rainwater collection system is often made by conventional method,

There is no calculation on the amount of rainwater to be drained out. The

collection system is not correctly designed => the system is overloaded.

High building: no exterior walls Seno roof => collection hopper is

arranged within the roof space and the number of them is limited.

III. RESULTS

2. Sewerage system

Most sewer pipes are under wall and under floor types.

Public buildings often have separate male and female toilets, but the

amount of sanitary equipment is still less than the demand, old and unhygienic.

The percentage of wastewater connected to sewer network of the city

is low (<50%). In many families, after through a septic tank, wastewater directly

into the soil permeability. The Design of Septic tanks is completely conventional.

100% of public buildings have septic tanks connected to the city sewer

network

SchoolFlush toilet

(person/Appliance)

Urinals

(per/Appliance)

Sink

(person/Appliance)

TCVN

(person/Appliance)

College 35 36 60 40

High school 28 52 53 30

Secondary

School32 24 49 30

Primary 28 24 48 20-30

Nursery

school12 16 16 20-30

III. RESULTS

3. Other issues

- Indoor Sewer systems are without ventilation, septic tank sludge is

not discharged regularly and leads to occlusion, smelly water overfills onto

the ground level.

- Some households put detergent wastewater, wastewater into septic

soap this reduces the performance of the tank.

- Some hospitals don’t have wastewater treatment systems: Thanh

Khe Hospital, Dermato-Venereology hospital, Lien Chieu hospital, 17 Military

Medicine.

III. RESULTS

IV.CONCLUTIONS AND RECOMMENDATIONS

1. Conclusions

* Water supply

- The percentage of households, public buildings used tap water is high

>95%.

- Average water use depends on the level of appliances and water use

habits. Average water use counted for the whole city is 146 l/person/day.

- Most of data shows amount of water use in households and public

buildings less than standard TCVN 33-2006, TCVN 4513-1988.

- Diagram of water supply that used in households is mostly the same, it

is the water system with roof tank and in public buildings is Storage tank –

Pum – Tank

* Water drainage

- The percentage of wastewater connected to sewer network of the city

is low.(<50%)

- Public buildings: the amount of sanitary equipment is still less than the

demand.

- Some hospitals have not wastewater treatment systems

2. Recommendations

- Update water use standards for the consistency with reality in

computing, design water supply and drainage systems inside

buildings.

- Construction and renovation of sewer network to enhance the rate

of households with sewage connections to the network.

- Expand the scope of investigation and the investigation period in

Danang as well as for other provinces and cities in Vietnam.

IV.CONCLUSIONS AND RECOMMENDATIONS

Thank you for your attention!