Singapore Water Supply Case Study

Question 1

Water use distribution

Answer 1

• Domestic: 45%
• Industry: 50%
• Agriculture: 5%

Question 2

Explaining distribution

Answer 2

• SG grows only 8% of vegetables –> relies on import
• 20 -25% of industry is manufacturing of chemicals, electronics, transport engineering etc.
• Domestic sector use bc of high quality of life: 25th on Mercer’s survey 2019

Question 3

Water supply issue

Answer 3

• limited land to collect and store rainwater
• lacks natural resources for water
• Relies on imports from Malaysia based on 1962 water agreement –> expires in 2061, multiple disputes with Malaysia about raw water price

Question 4

Methods of water supply

Answer 4

4 taps:

• Local catchment
• Desalination
• NEWater
• Imported water

Question 5

Local catchment

Answer 5

• Collects rainwater and stores in 17 reservoirs for use
• Lack of space to collect collectible rainwater that falls on 2/3 rds of country
• Uses network of drains, canals etc.
• Marina reservoir newly built in 2011 can provide up to 10% of water needs

DA:

• Dependent on rain –> ineffective in drought
• Takes up land space (but also used for recreation so ok)

Question 6

Imported water

Answer 6

• Allowed to retrieve 250m gallons of water from Johor river daily
• In return provides them with 2% of our treated water
• Extracted from Johor river Waterworks

DA:

• Agreement expires in 2061 –> needs to be more self reliant
• increases reliance on other countries
• cause of political disputes –> disputes from 2000 onwards regarding price adjustments to agreement

Question 7

NEWater - General info & DA

Answer 7

• Closes water circle
• Uses recycled water and cleans it to form ‘ultra-clean high grade water’
• Membrane technology which has advanced in affordability and quality from 1990s.
• Water used for industrial and indirect potable purposes
• Passes WHO’s and USEPA’s tests
• Currently 5 plants that can provide up to 40% of needs

DA:

• Society may not accept
• ex to run machines

Question 8

NEWater - Process

Answer 8

• Microfiltration: filter out impurities/ pathogens
• Rev osmosis: membrane through which only water can pass, removes viruses and bacteria more
• UV disinfection: acts as guarantee of purity by getting rid of any possible pathogen
• pH balance: alkaline substances added to make pH balanced

Question 9

Desal

Answer 9

• unaffected by weather, uses the sea
• membrane tech to remove salt and impurities
• Currently 3 plants - Tuas Tuas south and Sing Spring

DA:

• Expensive/ energy intensive
• Brine & concentrated water let out into sea. Doesn’t change concentration of sea on large scale but can have local impacts. –> needs to be done carefully

Question 10

Change by 2061

Answer 10

Predicted comsumption:

• 70% industry, 30% domestic
• Increase dep. on NEW and desal
• Pred. 30% Desal, 55% NEW