Sunday, October 13, 2019
The Issues Of Fresh Water In Singapore Environmental Sciences Essay
The Issues Of Fresh Water In Singapore Environmental Sciences Essay Singapore is an island and urban city state with no rural hinterland and hence, it has been depending on Malaysia for nearly forty percent or more of its water supply. However, Singapore is not short of fresh water as it receives an average of around 2,400 mm of rainfall annually. The only constraint faced by the country is capturing and storing as much of this rainfall as possible, on limited amounts of land areas, so as to achieve self-efficiency in water issues. Recycling efforts in Singapore started in 1966 when the Jurong Industrial Water Treatment Plant was commissioned to supply industrial water to the Jurong Industrial Estate (JIE). This water comes from treated sewerage effluent and is meant for industrial use in the Jurong area as well as by several oil refineries. The Singapore government encourages industry and private enterprises to recycle water. Also, tax rebates have been provided for factories that install water-saving plants. Bottles of NEWater Singapore has also developed NEWater, a three-stage process which brings waste-water to a quality that is better than that produced by the Public Utilities Board (PUB). Treatment begins with Microfiltration to remove suspended solids, colloidal particles, bacteria and viruses. The next process is Reverse Osmosis, which involves applying of pressure for water to flow from the concentrated side to the less concentrated side through a semi-permeable membrane to remove inorganics like heavy metals, such as nitrate, chloride, sulphate etc. The third process, Ultra-violet disinfection, is a safety back-up to remove any bacteria or viruses that cannot be removed by Reserve Osmosis. Desalination is a process of removing excess salt from water (eg. seawater) to enable it for drinking purposes. It has been used to augment water for some time, but it was not adopted as a matter of policy until recent years. This method is considered successful, as this source of supply produce 12% of Singapores daily water needs. Although desalination costs under current improved technology are higher than traditional means of treatment, Singapore has decided to go ahead in the belief that new technologies will reduce the costs further. 3. Impoundments and reservoirs Singapore has several impounding reservoirs inland including Seletar, Peirce and MacRitchie etc. To increase storage capacity, seven reservoirs have been developed by damming the river mouths. It was in that context that a plan to maximise collection of surface resources by extending the present 24.3 square miles of collection grounds to 156 square miles (about 75% of the islands total area) was proposed. However, geological conditions limited the availability of groundwater, hence the plan focused on retrieval of stormwater and water recycling instead. Another reservoir which was built in the recent years was Marina Barrage, which was officially opened on 30th October 2008. Marina Barrage is a dam built across the Marina Channel. Water flows into the reservoir from some of Singapores most well-known waterways, including the Singapore River, Stamford Canal, Rochor Canal, Geylang River and the countrys longest river, Kallang River. Marina Barrage was envisioned by Prime Minister Lee Kuan Yew in 1987, after the great clean-up of the Singapore and Kallang Rivers. Building the barrage on the soft sea bed amidst changing currents and constantly moving marine traffic was a major challenge. From the air, the pump house of the barrage looks like that number 9, which signifies longevity in Chinese. This major engineering achievement is symbolic of Singapores development as a City of Gardens and Water. How Marina Barrage works? The Barrage acts as a physical barrier to separate the reservoir from the sea. The steel crest gates of the Barrage will act as a tidal barrier to keep the high tides out. Under normal conditions, the crest gates will remain in an upright position to isolate the reservoir from the sea. During heavy rains that collide with low tide, the steel crest will be lowered to release excess storm water into the sea. During heavy rains that collide with high tide, the steel crest gates remain erect, hence storm water cannot flow out to sea naturally. Instead, large drainage pumps will be operated to pump water out to sea. With the Barrage in place, the pockets of low-lying areas in the city will no longer be prone to flooding. 4. Stormwater run-off Harnessing stormwater at minimum cost requires proper land-use planning and pollution control to ensure that stormwater run-off can be efficiently collected and that pollution levels are low. Stormwater harvesting from urban land was consistent with the overall policy of land use in this land-scarce republic, in which land was seen as too valuable for its use to be restricted to a single purpose such as for housing. In the words of the Minister for National Development: If we designate more land for water catchments, there will be less land for housing and other developments. The reverse is also true. Optimising and maximising the use of land and water helped the country to overcome constraints to a certain extent. (Adapted from: The Straits Times,1996) Singapore was the first country in South-East Asia (SEA) to develop viable stormwater run-off schemes. Among the various schemes, the Bedok and Lower Seletar Schemes are the largest. Surface water for these schemes comes mainly from the housing estates and new towns of Ang Mo Kio, Bedok, Tampines and Yishun and the area near Changi International Airport. Water is conveyed to the storage reservoirs of Bedok and Lower Seletar. One important feature of this scheme is the emphasis on close co-ordination between several agencies, such as the Housing Board Development (HDB), the Ministry of the Environment (ENV) and the Planning Department, in order to ensure that water collected from urban surfaces is low in pollutants. In addition, the drainage system designed in such a way that it channels water through concrete channels to suitable collection ponds situated at topographic low points. An automatic monitoring system ensures that only discharges produced by heavy storms resulting in run-o ff above a certain volume are collected. One example of the innovative approach to stormwater collection is making use of the empty space under the interchange of the Seletar and Bukit Timah expressways for a water collection pond. 5. Conservation of water In addition to developing and diversifying water resources, water conservation is also key to ensuring a sustainable water supply. Through our various water conservation initiatives, Singapore has managed to reduce domestic water consumption from 172 litres per capita per day in 1995 to 157 litres in 2007.(Adapted from Conserve, Values and Enjoy by Ministry of Environment and Water Resources, 08 July 2008) It is a difficult task to keep looking for new sources of water, but the situation can be improved if we can control our ever-increasing demand of water. To provide water for all, PUB calls on all Singaporean to play our part in water conservation and to keep our water catchments and waterways clean so that we can enjoy our water resources. One way to discourage excessive use of water is to impose water conservation tax on the amount of water used. This additional tax is added to the price of the water consumed by households and varies according to the amount of water they use. A household that consumes more water will pay higher taxes compared to household that used less water. Additionally, there are varieties of activities organised to teach Singaporeans to view water as a scarce and precious resource, and to use it wisely. Water conservation talks are conducted in schools and leaflets on water conservation are distributed to households. Water-rationing exercises, where the supply of water to some homes is temporarily cut off, are also carried out in housing estates. Effectiveness of the solutions implemented by government So far, Singapore has been able to tackle the problem of a limited supply of fresh water with the introduction of water reclamation, desalination of sea water and impoundments. Technological innovations in modern society have enabled us to have larger catchment areas, to build dams and to obtain fresh water from sea water and used water. Policies aimed at water conservation have also produced certain positive results. Based on the research conducted by the Ministry of the Environment and Water Resources, the domestic water use per person has generally fallen between 1995 and 2007, from 172 litres per day to 157 litres per day. This means that Singaporeans are more aware of the challenge they are to face nowadays. Introduction of water conservation taxes and activities about water conservation also help to spread awareness about the importance of water conservation. Recommendations regarding the current policies from our committee Government can introduce fine of a certain amount of money for over-usage of water. This means that if the households use unusually large amount of water every months, the government could send down the letters to inform them that they have used too much water compared with the national average, and they should manage their usage well from now on or the authority would have to take action in order to save water. In case if the household owners do not take mind of the warnings, they would be fined. Similarly, households have done well in controlling the water usages should be rewards for their effort put in. For example, tax-relief can be introduced to residents who use water-saving devices at home. Measures like this can encourage the people to install water-saving devices in their houses, hence the overall usage of water would gradually drop to an acceptable level, and the people can be satisfied with rewards given by government for their well-being as the citizens. Examples of water-saving devices: Shower head Water-saving tap Toilet stop Such water-saving devices help reduces water usage at our homes. We uses 9 litres of water whenever we flush the toilet. A toilet stop can be used to cut down the usage of 9 litres. It is added to the toilet flushing mechanism to stop the flushing when the handle is released. Thus if used wisely it allows people to save up to 20% of their total water bill.
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