DEPARTMENT OF ENVIRONMENTAL PROCESS AND CONTROL ENGINEERING- KNOW YOUR WATER

CHAPTER 1: WATER RESOURCES IN HO CHI MINH CITYGroundwater is considered a non-renewable source of fresh water since pumping exceeds recharge in most aquifers used as sources of fresh wat

MINISTRY OF NATURAL RESOURCES AND ENVIRONMENT

HCMC UNIVERSITY OF NATURAL RESOURCES AND ENVIRONMENT

DEPARTMENT OF ENVIRONMENTAL PROCESS AND CONTROL ENGINEERING

ACADEMIC ENGLISH ASSIGNMENT

TOPIC

KNOW YOUR WATER

Professor : Dr LY CAM HUNG Student : PHAN THAI BINH Student ID :

Class : 02 DHQTTB

HO CHI MINH CITY, 2016

0

MINISTRY OF NATURAL RESOURCES AND ENVIRONMENT

HCMC UNIVERSITY OF NATURAL RESOURCES AND ENVIRONMENT

DEPARTMENT OF ENVIRONMENTAL PROCESS AND CONTROL ENGINEERING

ACADEMIC ENGLISH ASSIGNMENT

TOPIC

KNOW YOUR WATER

Professor : Dr LY CAM HUNG Student : PHAN THAI BINH Student ID :

Class : 02 DHQTTB

HO CHI MINH CITY, 2016

1

TABLE OF CONTENTS

CHAPTER 1: WATER RESOURCES IN HO CHI MINH CITY 1

1 Dong Nai River 2

2 Sai Gon River 2

CHAPTER 2: WATER TREATMENT TAN HIEP WATER TREATMENT 4

CHAPTER 3: FACTS ABOUT WATER 6

1 WHAT IS WATER? 6

2 WATER FOOTPRINT 7

3 WATER RIGHTS 8

CHAPTER 4: WATER WISE 9

1 TOILET 10

2 RAINWATER 10

3 SHOWERHEADS 11

4 FAUCETS 11

5 CLOTHES WASHER 11

REFERENCES 12

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CHAPTER 1: WATER RESOURCES IN HO CHI MINH CITY

Groundwater is considered a non-renewable source of fresh water since pumping exceeds recharge in most aquifers used as sources of fresh water Surface sources of fresh water, such as lakes and rivers, are considered renewable It is generally agreed that the total amount of water that circulates annually from the earth’s surface to the atmosphere and back down to the earth has remained fairly constant in recent times Therefore, on average, rivers and lakes produce the same amount of fresh water now as they did 100 years ago However,the population of the world has increased more than six-fold in the last 100 years, adding demands

At present, four water resources are used for water supply in Ho Chi Minh City They are Dong Nai River, Sai Gon River, groundwater and rain water The current and projected total daily water use demand for domestic and industrial activities in Ho Chi Minh City were 1.75 million m3 in 2005 and 3.6 million m3 in 2020, respectively The key water users in HCMC are residents, industries and services Water resources used for agriculture in Ho Chi Minh City are raw water taken from the irrigation canals network of Sai Gon and Dong Nai Rivers and storm water in the rainy season Ground water has not been used for agriculture in Ho Chi Minh City because of availability of fresh raw water of the irrigation canals located in the west and southeast of HCMC and unsuitability of groundwater quality for irrigation, such as high iron content and low

pH

The Saigon Water Supply Company (SAWACO) is responsible for exploitation, purification and distribution of water in Ho Chi Minh City The capacity of piped water

in 2006 under SAWACO’s management was 1,236,000 m3 /day, which included 1,150,000 m3 /day produced by three surface water treatment plants taking raw water from Sai Gon and Dong Nai Rivers and 86,000 m3 /day produced from groundwater treatment plants

The total volume of water for domestic and industrial uses in Ho Chi Minh City was about 1,890,000 m3 /day in 2006, which included 1,270,000 m3 /day taken from Sai Gon and Dong Nai Rivers Nga (2006) reported the maximum exploitation rates of freshwater from Sai Gon and Dong Nai River basins could obtain 7,500,000 m3 /day, which included: - 940,000 m3 /day from Sai Gon River and up to 1,360,000 m3 /day when Phuoc Hoa reservoir is built, - 200,000 m3 /day from Dau Tieng reservoir and Dong Canals, - 6,000,000 m3 /day from Dong Nai River

The total volume of water for domestic and industrial uses in HCMC was about 1,890,000 m3 /day in 2006, which included 1,270,000 m3 /day taken from Sai Gon and Dong Nai Rivers Nga (2006) reported the maximum exploitation rates of freshwater from Sai Gon and Dong Nai River basins could obtain 7,500,000 m3 /day, which included: - 940,000 m3 /day from Sai Gon River and up to 1,360,000 m3 /day when

Phuoc Hoa reservoir is built, - 200,000 m3 /day from Dau Tieng reservoir and Dong Canals, - 6,000,000 m3 /day from Dong Nai River

1 Dong Nai River

Dong Nai River originates from Di Linh highland in Lam Dong province and connects to the East Sea through Soai Rap estuary The total length of the river is 628 km The total river basin area is 38,610 km2 Other downstream sections of the river have an average slope of 0.22‰ The middle and upstream sections of the river have an average slope of 0.94‰ and 4.34‰ respectively The section of Dong Nai River in HCMC spreads from District 9 to intersection point with Nha Be River Total length of this section is 40 km and average width is 200-300 m The flowrate of Dong Nai River was from 100 m3 /s (maximum) to 32 m3 /s (minimum) However, when flow from Tri An reservoir was added, the flow rate increased to 2,110 m3 /s maximum flow and 600 m3 /s minimum flow Due to the discharge rate of Tri An reservoir and Dau Tieng reservoir, a salinity limit of 4‰ is pushed back to Cat Lai, 10 km long from its first present point (Hiep Binh crossroad) When an additional flowrate of 20 m3 /s from Thac Mo lake is discharged to the Dong Nai River, the salinity point is 4-5 km further than its previous position

2 Sai Gon River

A section of Sai Gon River in HCMC begins from Phu My commune to Thanh My Loi, District 2 Width of the river is 250-350 m The river depth is 10-20 m Maximum flowrate was 84 m3 /s in October, 1986 (recorded at T3 station, Binh Duong Province) and minimum flowrate was 22.5 m3 /s in August, 1986 Maximum and minimum water level were 1.18 m (10th October, 1990) and -0.34 m (20 October, 1990) Sai Gon River

is affected by semi-diurnal tidal flow regime Dau Tieng reservoir affects a large area of Sai Gon River basin (2,700 km2 ) Its volume is 105 million m3 It supplies water for irrigation and a clean water supply in Tay Ninh province and HCMC The irrigation canal system of Sai Gon River is also a significant freshwater recharge source for the groundwater aquifers in the canals basin, located in the west and southwest of HCMC Moreover, the lake also contributes to pushing back the salinity point because it discharges water to the downstream of Sai Gon River at a rate of 20 m3 /s In Sai Gon River, there is a salinity point of 4‰ at Thu Thiem Water from Hoa An water intake station on Dong Nai River is pumped to Thu Duc water treatment plant (WTP) with a capacity of 650,000 m3 /day Binh An WTP, which takes raw water from Dong Nai River, has 95,000 m3 /day These two WTPs supply clean water for the eastern part and center of HCMC The Sai Gon WTP with a design capacity of 300,000 m3 /day (at Ben Than-Cu chi District) started running at a capacity of 120,000 m3 /day in 2004 and will

be run at the designed capacity in 2007 It takes raw water from Saigon River and supplies clean water to the western part of HCMC The socio-economic development plan of HCMC People’s Committee for period 2001–2020 (VIWASE, 2004) shows that

the quantity of piped water increases to 1,670,000 m3 /day; 2,180,000 m3 /day and 3,290,000 m3 /day in the years 2004, 2010 and 2020, respectively

The master plan of water supply of HCMC shows that Dong Nai River will be the main water uptake source, at which 57.3% and 62.3% of total water demands of 2010 and

2020 would be taken up, respectively Besides HCMC, the provinces of Sai Gon and Dong Nai Rivers basin such as Dong Nai, Binh Duong, Ba Ria-Vung Tau, Tay Ninh and Long An provinces also use Dong Nai and Sai Gon Rivers

CHAPTER 2: WATER TREATMENT TAN HIEP WATER TREATMENT

The Tan Hiep Water Treatment Plant (THWTP) was constructed in 1992 It is located at Thoi Tay 1 commune, Tan Hiep ward, Hoc Mon district, Ho Chi Minh city, Vietnam The treatment plant is located on a 16 ha campus and affiliated with the Saigon Water Corporation On 23 July, 2009, treated water from the THWTP was integrated officially

to the water supply network of Ho Chi Minh City (HCMC) The operation of the plant added a new water source and satisfied the needs of clean water for more than 3 million people in the area of districts 6, 8, 10, 11, 12, Go Vap, Tan Binh and Tan Phu, Binh Tan, Nha Be and Binh Chanh

THWTP supplies between 285,000 and 300,000 m3 /d Extracting raw water from the Saigon River, Hoa Phu pumping station delivers water to the THWTP Here, the water is treated in a traditional manner using the following processes: flocculation, primary sedimentation, sand filtration, disinfection, storage

The major process is as follows: Saigon river → Raw water pumping station (lime, chlorine) → Function tank → Mixing tank (PAC) → Sedimentation tank → Rapid Sand filter tank → Backwash water chamber (fluoride) → Clean water reservoir (chlorine) → Clean water pumping station → Distribution network There is no sludge treatment system in THWTP

At THWTP, raw water is firstly stored at function tank to stabilize the flow before distributing to the treatment works Water from function tank is transferred to mixing tank by canal with the width and height of 2 x 2 m Mixing tank is the hydraulic form with vertical flow direction walls Previously, aluminum sulfate (Al2(SO4)3.16H2O) was used as flocculant with dosage of 16-30 mg/L (depending on the raw water quality), but since December 2009, liquid PAC (Poly aluminum chloride, 10%) is being used PAC has better flocculation efficiency and more facilitate operational management than aluminum sulfate

To optimize the flocculation process, lime is added at the end of mixing tank to adjust the pH of approximately 6.5 - 6.9 Water from the mixing tank is directed into sedimentation tank through a drain system Sedimentation tank is designed with suspended sludge blanket type Maintaining the sludge blanket helps to determine performance of the sedimentation tank To ensure that the sludge blanket is not too thick, the amount of excess sludge from the settling tank is discharged automatically after each 15 minutes The hydraulic retention time of sedimentation tank is 2 h with the surface loading rate of 2.36 m3 /m2 h The each sedimentation tank is cleaned frequently once every 6 months

After settling, settled water is transferred to the rapid sand filter tank There are 12 filters with an average surface loading rate of 9 - 9.5 m3 /m2.h The filtration velocity is

8.3 - 9.96 m/h The effluent water from filtration tank has the turbidity of 0.38 NTU The water is filtered through quartz sand of effective size 0.7 - 1.2 mm and sand layer thickness of 0.9 m After operating of 48-72 h, the backwash step (water wash with air scour) for filtration tank is conducted Backwash consumes 10 – 12 % of clean water produced

Lime, fluorine and chlorine are added to filtered water to stabilize water, to fight tooth decay and to disinfect water Clean water after leaving the clean water reservoir is added with chlorine again in order to maintain the amount of residual chlorine in the water supply system before being pumped to the water network

A surge tower is located near the main gate of the plant This tower serves multiple functions, such as; to provide clean water to turbine at startup phase

 to prevent collapse of penstocks because of water pressure drop at turbine start

up, and

 to prevent penstock explosion at turbine shut down due to pressure increase since

 momentum of water from head pond-pressure is dissipated up into the tower

CHAPTER 3: FACTS ABOUT WATER

1 WHAT IS WATER?

Water is a liquid, but can have a solid state (ice) and a gaseous state (water vapour or steam) as well Water covers much of the earth’s surface, and is found mostly in the form of oceans Only 3% of the world’s water is fresh, with less than 1% easily accessible fresh surface water The rest is groundwater and ice In the earth’s atmosphere, tiny water droplets and ice crystals that are suspended in the air form water vapour or clouds Together, the oceans, polar ice and clouds make our entire planet look blue and white from outer space This is why the earth is known as ‘the Blue Planet’

Water covers about 70% of the world’s surface, and all life forms, including humans, depend on it for theirbasic survival However, about 97% of the world’s water is in the oceans and is considered highly saline Ice located near the earth’s poles, accounts for about 2% of the earth’s water About 0.6% of the world’s water is fresh water stored below ground (groundwater), often thousands or millions of years ago The atmosphere and the soil environment account for about 0.06% of the world’s water About 0.01% of the world’s water is found in lakes, rivers, and streams

Groundwater is considered a non-renewable source of fresh water since pumping exceeds recharge in most aquifers used as sources of fresh water Surface sources of fresh water, such as lakes and rivers, are considered renewable It is generally agreed that the total amount of water that circulates annually from the earth’s surface to the atmosphere and back down to the earth has remained fairly constant in recent times Therefore, on average, rivers and lakes produce the same amount of fresh water now as they did 100 years ago However,the population of the world has increased more than six-fold in the last 100 years, adding demands on fresh water resources

World Water Day is held annually on 22 March to focus attention on the importance of fresh water, and to promote the sustainable management of freshwater resources The City of Cape Town celebrates Water Week annually with a programme of activities throughout the city to highlight the need for water security and conservation It also gives recognition to people and projects that have improved access to drinking water for our citizens

Why irrigate with treated drinking water when you can meet your irrigation needs through an effective greywater system? What is greywater? Greywater includes all wastewater generated in the home, except toilet water (which is considered

“blackwater”) Kitchen sink and dishwasher water are also categorized as “blackwater” Greywater is an abundant resource in both residential and commercial buildings According to Brad Lancaster of the Watershed Management Group in Tucson, Arizona,

“greywater harvesting is the practice of directing greywater to the primary root zone

(top 2 feet or 0.6m of the soil) of perennial plants to help grow beautiful and productive landscapes while achieving wastewater treatment without using energy or chemicals Plants and microorganisms in the soil consume and filter the organic nutrients and bacteria found in greywater, treating it naturally and returning clean water to the water cycle” (Lancaster, 2010, p.294) Though not suitable as drinking water, greywater can

be used for irrigation, particularly of trees and shrubs whose woody stems serve as additional filters for contaminants that may be present Clearwater is solid-free wastewater which includes water produced while waiting for hot water from the faucet

to heat up, refrigerator compressor drip, swamp cooler and air conditioning ‘sweat,’ and more Clearwater, like greywater, is an underutilized landscape irrigation resource ripe for harvest in most commercial buildings and homes

2 WATER FOOTPRINT

Knowing exactly how much water is used in our daily lives helps us understand how important it is to use it wisely Generally, we think about the water needed for drinking and cleaning only However, we should also think about the water required to produce the goods we buy and the food we eat The ‘water footprint’ is a measure of the total amount of fresh water that is used to produce goods and services

People use lots of water for drinking, cooking and washing but even more is used for growing our food and for making our clothing, cars or computers

The water footprint measures the amount of water used to produce each of the goods and services we use It can be measured for a single process, such as growing rice, for a product, such as a pair of jeans, for the fuel we put in our car, or for an entire multi-national company The water footprint can also tell us how much water is being consumed by a particular country – or globally – in a specific river basin or from an aquifer

The water footprint looks at both direct and indirect water use of a process, product, company or sector and includes water consumption and pollution throughout the full production cycle from the supply chain to the end-user

It is also possible to use the water footprint to measure the amount of water required to produce all the goods and services consumed by the individual or community, a nation

or all of humanity This also includes the direct water footprint, which is the water used directly by the individual(s) and the indirect water footprint – the summation of the water footprints of all the products consumed

“The interest in the water footprint is rooted in the recognition that human impacts on freshwater systems can ultimately be linked to human consumption, and that issues like water shortages and pollution can be better understood and addressed by considering