To Conserve Water by Using Rainwater Harvesting System as an Approach to Achieve Sustainable Water Efficiency in S11 House
Asian Architecture [ARC 2213/2234] PROJECT 1: CASE STUDY
To Conserve Water by Using Rainwater Harvesting System as an Approach to Achieve Sustainable Water Efficiency in S11 House
NAME:
KRISTINE YONG XI WEI
STUDENT ID:
0311297
LECTURER:
PN.NORHAYATI
SUBMISSION DATE:
9TH JUNE 2015
1| ARC 2213/2234 Asian Architecture
To Conserve Water by Using Rainwater Harvesting System as an Approach to Achieve Sustainable Water Efficiency in S11 House
Table of Contents
Page
Abstract......................................................................................................................... 3
1.0 Introduction ............................................................................................................. 4
2.0 Overview of rainwater harvesting system ................................................................ 5
3.0 Impact of storm water runoff on the environment..................................................... 7
4.0 Conserve water and low running cost.................................................................... 10 5.0 Maintenance and improvement of water quality .................................................... 13
6.0 Conclusion ............................................................................................................ 16 7.0 References............................................................................................................ 18
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To Conserve Water by Using Rainwater Harvesting System as an Approach to Achieve Sustainable Water Efficiency in S11 House
Abstract The purpose of doing water conservation by using rainwater harvesting system as an approach to achieve sustainable water supply in S11 House is to identify the possibility and importance to conserve water for future demand by reducing main water use. By using rainwater harvesting system, rain water will be capture by slanted rooftop catchment area or a simple vessel to maintain the landscape and environment. The purpose of reduction of energy consumption and climate change are to achieve the availability, safety, and sustainability of natural resources by using rainwater harvesting system. In this research, literature reviews will be based on the various aspects of rainwater harvesting system achieve sustainable water supply and water quality in S11 House. Large slanted rooftop catchment area is where the rain water has been capture. Filtration will be bring out for drinking water. Rainwater harvesting system could save energy directly by reducing potable water demand. Hence, integrating rainwater harvesting system with conventional water collection and distribution suggest a potential method of reducing energy use in another way, water quality still be sustained. Water quality monitor such as chemical measurement, physical measurement and biological measurement conducted to state the pollution control agencies such as characterize waters and identify changes or trends in water quality. Local treatment of harvested water could easily make water potable as well as nonpotable. Rainwater harvesting is a more effective technology which could easily undertake through normal equipment during water crisis. Hence, as a conclusion, methods of using natural water in a sustainable manner.
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To Conserve Water by Using Rainwater Harvesting System as an Approach to Achieve Sustainable Water Efficiency in S11 House
1.0 Introduction S11 House is the building that I have choose to make a study on the conservation of water to sustain water efficiency. S11 House is designed and owned by architect Dr. Tan Loke Mun of ArchiCentre Sdn Bhd, the award winning home comprises a wide range of green elements in design and construction. This building is located in an established older suburb of Petaling Jaya. S11 House achieve Malaysia’s first GBI Platinum (DA) rated residential home. This rating was given based on 6 key criteria, one of them is water efficiency (WE). In S11 House, water efficiency criteria is based on rainwater harvesting, water recycling and water-saving fittings. For garden irrigation, blackwater needs to be treated in the onsite sewerage treatment plant and recycled water needs to be used. Besides that, large canopy roof is to collect more rainwater for the usage of household, irrigation and drinking purposes. The large canopy roof in S11 House is pitched at 5 degrees to facilitate self-cleaning of roofing material and first-flush before the water flows into the storage tank. Rainwater that collected on the canopy roof drains directly into the series of rainwater harvesting tanks for sedimentation control and water from the last tank used for all the toilet flushing, landscape irrigation and car washing requirements. Blackwater of swimming pool and koi pond will be treated in the onsite sewerage treatment plant and the recycled water is used for garden irrigation. The water saving and reduction valves involve of all the tap fittings and sanitary wares to prevent leakage and wastage. “In fact, studies show that 55% of domestic treated water could be substituted for rainwater, while 85% of water does not need to be drinking standard due to the purpose of commerce and industry used” (Thompson, 2015). Rainwater harvesting system in S11 House is to provide green movement, sustainability, cost saving and water restriction. The total site area of S11 House is 1,240 square meter and consist of swimming pool and koi pond which are costly for water usage. The purpose of using rainwater harvesting system in S11 House helps water utilities reduce peak demand and delay expensive infrastructure expansion. This will reduce the consumers’ utility bills. Rainwater harvesting can not only help
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To Conserve Water by Using Rainwater Harvesting System as an Approach to Achieve Sustainable Water Efficiency in S11 House
conserve water supplies, it can also bring significant cost savings for properties on water meters. Rainwater harvesting make the best use of a natural resource that we simply can no longer afford to pitch down into the drain, whereas it provides a sustainable means of conserving water supplies.
Question 1: What is the technique of rainwater harvesting system and the possibility amount of the water could be captured in S11 House? Question 2: How does rainwater harvesting system save and large reduction in utilities bill in S11 House? Question 3: How does rainwater harvesting system maintain and improve water quality in S11 House?
2.0 Overview of rainwater harvesting system Rainwater harvesting system is all about capturing, storing and filtering storm water from roofs, downspouts and surface run-off. This system is based on the volume and frequency of rainfall and surface area of the catchment to generate sufficient water for the intended purpose to reduce the consumption of ground water. Rainwater harvesting also implemented with other efficiency measures such as water efficiency and energy efficiency. As it is a renewable energy resources therefore, water produce and filter not through burning with non-renewable resources such as coal, natural gas, and petroleum but with its own treatment and filter pump. This system act independently which inherent their own responsibility of operation and maintenance.
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To Conserve Water by Using Rainwater Harvesting System as an Approach to Achieve Sustainable Water Efficiency in S11 House
Figure 1 Flow of Rainwater Harvesting System. The best catchment systems have hard and smooth surfaces for instance metal roofs or concrete surface. The quantity of water collected depends on the quantity of rainfall, surface area and degree of slope of the catchment area. Gutter and downspouts is the distribution systems that channel water from catchment area to a container such as barrel, cistern, planted area, etc. then it will be channel into a screen that removes debris. “First flush” will be taken before the rainwater enter into the storage tank. The “first flush” water will diverted to outside of the storage system. There are a total of 5 storage tanks with 500 gallons each in S11 House. Two of the storage tank is for storing rainwater whereas another three storage tanks is for the filtered water which is ready to be used for household purposes. Water for drinking purposes will then delivery to a purification system or pass through a treatment for detailed filtration to make sure all the dirt, sediments, and debris removed.
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To Conserve Water by Using Rainwater Harvesting System as an Approach to Achieve Sustainable Water Efficiency in S11 House
Figure 2 Location of storage tank in S11 House. Source: (S11house.com, 2015)
3.0 Impact of storm water runoff on the environment Storm water runoff is the precipitation that flows over the ground surface. Precipitation in an urban or suburban area that does not evaporate or soak into the ground instead runs across the land and channel into the nearest waterway is considered as storm water runoff. According to NAHRIM, the average annual precipitation of Malaysia is 2500mm (NAHRIM, 2008). S11 House located at a suburban area where flooding can happen anytime which causes water pollution and overflowing of sewers. This will needed chemical treatment to process for clean water for drinking purpose and household use. Therefore, S11 House make use of natural resource to reduces flood, storm water runoff, and contamination of surface water with pesticides, sediment, metals and so on. S11 House uses large slanted rooftop catchment area to capture and collect rainwater. Ar. Dr. Tan Loke Mun uses the 7| ARC 2213/2234 Asian Architecture
To Conserve Water by Using Rainwater Harvesting System as an Approach to Achieve Sustainable Water Efficiency in S11 House
traditional knowledge, skills and types of material of roof to produce the rainwater harvesting system. The roof that he uses in S11 House is reflective foil which has smooth surface. Pitched roof is recommended to be use to collect sufficient rainwater and provide first flush.
Figure 3 Rainwater Harvesting system in S11 House.
Rainwater yield varies with the texture and size of the catchment area. Based on figure 3, S11 House uses a 5 degree pitched reflective foil roof to capture water into the gutter then downspout. The degree of pitched roof affects how quick the water run and can reduce the possibility for contamination to remain on the catchment surface. The size of the catchment 8| ARC 2213/2234 Asian Architecture
To Conserve Water by Using Rainwater Harvesting System as an Approach to Achieve Sustainable Water Efficiency in S11 House
area determine the quantity of rainwater can be harvested. Pipe 4 is the downspout which channel the debris of “first flush�. Pipe 1 is the collection of rainwater from top. Pipe 2 is for overflow of water from storage tank whereas slope bottom of the tank helps channel out the sediments through pipe 3. Lastly pipe 5 uses gravity flows to channel water for toilet flushing, garden irrigation taps, and garage washing taps. Rainwater that used in garden irrigation provide quality with no chemicals for example fluoride and chlorine and no solidified salts and minerals from soil. Harvested water contain a variety of pathogenic microbes. Although water harvested from a roof-based collection system will usually contain few of these microbiological contaminants, treatment to the water is still needed as it is highly contaminated. It is difficult to have a treatment process that provides thorough protection against all pathogens. S11 House uses the combination of filters system to achieve adequate levels of protection from waterborne disease.
Figure 4 Roof plan of S11 House.
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To Conserve Water by Using Rainwater Harvesting System as an Approach to Achieve Sustainable Water Efficiency in S11 House
Source: (ArchDaily, 2013) S11 House has a large pitched catchment roof which allows plenty of rainwater be collected and store for needs. Malaysia is a rainforest country which has a 2500mm annual precipitation. To have the sufficient water for household use, calculation on the collection of annual rainwater harvested in S11 House is a crucial matter.
Figure 5 Calculation of total annual of rainwater collection in S11 House The surface of catchment area has been given to calculate the annual rainwater collection in S11 House. A 2250 square meter of roof area with 2500mm of annual precipitation will results in 4,566,250 litres of annual collection of rainwater. Besides that, there are swimming pool and koi pond in S11 House which need enough quantity of water supply to provide evaporative cooling.
4.0 Conserve water and low running cost As the urban population has increased which makes human ecosystem habitats and drivers of ecosystem changed. Severe environmental health problems which will occurs the result from scarce access to ecosystem services, such as clean water within urban 10 | A R C 2 2 1 3 / 2 2 3 4 A s i a n A r c h i t e c t u r e
To Conserve Water by Using Rainwater Harvesting System as an Approach to Achieve Sustainable Water Efficiency in S11 House
settlements. The initial cost along with additional costs, are weighed against the present value of future benefits. The maintenance costs are incurred for routine and corrective maintenance performed over the life of the system. These are the typically minimal for properly designed systems. According to Rainwater Harvesting Association, by using rainwater harvesting system for household use, garden irrigation, flush toilets, etc. can help to reduce water consumption by as much as 40% which is similar if you count it as water meter. It will reduce your water bill as well. The reason that S11 House is using rainwater harvesting as water supply is because it brings benefits to both the house and also the environment. Comparison between rainwater harvesting and graywater recycling will show more clearly the advantages for environment by using rainwater as potable and non-potable water. The amount of water you save with one of these system is lower than the 50% savings that you can possibly get with a graywater recycling system because rainwater supply is less assured. Environmental protection relies on recycling water wherever possible and collecting rainwater plays a huge role. Water recycling is the way forward to reduce waste and help in the environment. There is a possibility of reducing water bills and save money while reducing waste and recycle water. The purpose of use this system and save water is to prevent the depletion of ground water and augment the water table. S11 House uses rainwater harvesting system to collect water from natural rainfall as the simplest and priority technique. It would be the most easily adaptable method of qualifying water shortage during the time of water crisis. S11 House used this system not only to beneficial its site but also bring in plenty of advantage and reduce a lot of crisis for the public. It helps to inhibit the burden on the public water supply which is the main source of the city. Besides, it is also enough in case there is an emergency use such as fire or water shortage. This system allows unlimited 11 | A R C 2 2 1 3 / 2 2 3 4 A s i a n A r c h i t e c t u r e
To Conserve Water by Using Rainwater Harvesting System as an Approach to Achieve Sustainable Water Efficiency in S11 House
water for garden irrigation since it is natural water where there is no point to get complaints. This unlimited water for garden irrigation can help to extend soil moisture levels for development vegetation in this hot and humid country. The large canopy roof in S11 House allows to capture large quantity of rain, therefore groundwater level will highly recharged during rainfall to sustain water efficiency. S11 House needs large quantity of water for koi pond, swimming pool, and garden irrigation. If rainwater harvesting system is not used in S11 House, the water bill will be very high. Moreover, this system will helps to reduced dependency on water storage dams. Reduction of dependency means to reduce the amount of stress on dams and elimination to expand it. Since limited water supply and water shortage occurs often and it is costly and timely to produce through dams, therefore rainwater harvesting system will be more appropriate to be use. The user of rainwater harvesting system will appreciate a reduced amount of water consumption, thus all of the utility bills will greatly shrink in size. There will be a reduction of 30% to 50% of the bill without using this system.
Figure 6 Calculation of water bill in S11 House
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To Conserve Water by Using Rainwater Harvesting System as an Approach to Achieve Sustainable Water Efficiency in S11 House
Figure 7 Method of calculation Source: (Syabas.com.my, 2015) In S11 House, water usage for daily is about 1,434 gallons and yearly is about 521,976 gallons. According to SYABAS rate of consumption, S11 House uses 183.53 cubic meter per month which is about 321.91MYR. RM0.57 will be charge for the first 20 cubic meter, RM1.03 will be charge for the subsequent 15 cubic meter and RM2.00 will be charge for the remaining. The current water bill is about 150MYR can be saved per year, and about 1,900MYR can be saved in 1 years if rainwater is used for daily consumption. So within three to four years, the installation cost if a rainwater harvesting system can be returned.
5.0 Maintenance and improvement of water quality “It is predicted that 80% of all diseases and over one third of deaths are caused by consumption of contaminated water and on an average as much as 1/10th of each person’s productive time is sacrificed to water related diseases” (Goel and Patel, 2015). The quality of surface of water is deteriorated due to the indiscriminate discharge of untreated sewage and industrial effluents into natural water bodies. In an urban area, deteriorated water quality has a highest percentage which affect the safety of water supply, environment sanitation and health and alleviating poverty. Nowadays, many environmental challenges on the national horizon to preserving the quality and the availability of the freshwater resources. In Petaling Jaya, 30% to 13 | A R C 2 2 1 3 / 2 2 3 4 A s i a n A r c h i t e c t u r e
To Conserve Water by Using Rainwater Harvesting System as an Approach to Achieve Sustainable Water Efficiency in S11 House
40% of the municipal water is wasted through the distribution system. In this case, develop an appropriate and cost effective technologies, treatment and reuse of municipal wastewater are needed. Wastewater treatment should conform to pollution control standards for adopting reuse practice. S11 House uses the most economic disposal of wastewater from various sources which are, recycling, re-use, renovation and regeneration (4-R Concept). Rainwater harvesting system allows to recycle rainwater as potable and non-potable use. Whereas, rainwater for washing clothes and kitchen use will be filter and reuse for toilet flushing which known as greywater. Renovation refers to the high level treatment for suitable use like fresh water and regeneration refers to the natural manner for replenishment of a water source. For potable water, quality of harvested rainwater is an essential issue as it could be developed. The quality of harvested rainwater in S11 House from roof top depends on both the material of roof quality and the environments of the surrounding, such as, atmospheric pollution, climate, forth and so. Thus, it is crucial to perform a test to check on the capability and applicability before using as drinking water.
Figure 8 Standard data of rainwater system quality Source: (S11house.com, 2015). 14 | A R C 2 2 1 3 / 2 2 3 4 A s i a n A r c h i t e c t u r e
To Conserve Water by Using Rainwater Harvesting System as an Approach to Achieve Sustainable Water Efficiency in S11 House
For treatment of water, there are 2 suitable filtration of water can be taken at household level which are charcoal water filter and dewas filter. Charcoal water filter as shown in figure 9, contain the similarity to sand filter except that 10-15cm thick charcoal layer which results into better filtration and purification of water.
Figure 9 Charcoal water filter Source: (Gupta, 2015) Dewas filter as shown in figure 10, consists of PVC pipe 140mm in diameter and 1.2m long. It consists of three chambers, the first purification chamber has pebbles of size around 2 to 6mm, the second chamber is slightly larger which is between 6 to 12mm and the third chamber has largest 12 to 20mm pebbles. These means that the clean water flows out after pass through the three chambers by passing through a mesh at the out flow side. This is one of the most popular filter type used in rainwater harvesting system.
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To Conserve Water by Using Rainwater Harvesting System as an Approach to Achieve Sustainable Water Efficiency in S11 House
Figure 10 Dewas filter Source: (Gupta, 2015) Moreover, chlorination is to carry out for chemical disinfection. This can be done with stabilized bleaching powder with a mixture of chlorine and lime. Approximately 1gm of bleaching powder is sufficient to treat 200 litres of water which also can kill all types of bacteria and make water safe for drinking purposes. Furthermore, boiling water is another effective method for water purification. Water boil up to boiling temperature will kill and remove all biological contaminants. Water quality can affect waterborne disease if treatment is not done completely.
6.0 Conclusion Rainwater harvesting system is one of the valuable methods of using natural rainwater in a sustainable manner. Rain is the gift from nature. Densely populated cities should adopt this technology especially with a water crisis and adequate precipitation. In the future, water shortage in urban area will become the most concerned issue. Therefore, city developers and planners should reconsider the outcome, possibilities and benefits of using rainwater harvesting system and this system should have a policies to offer convenient and available to everyone. There are also some consideration of conservative ground water system on the basis of quality and quantity, 16 | A R C 2 2 1 3 / 2 2 3 4 A s i a n A r c h i t e c t u r e
To Conserve Water by Using Rainwater Harvesting System as an Approach to Achieve Sustainable Water Efficiency in S11 House
environmental impacts, water conservation and so on. Through S11 House, it is clearer to see that the impacts on storm water runoff, human health, water conservation, reduce cost and quality and quantity of water in a large scale. Awareness of water crisis should increase to led rainwater harvesting to be proposed as a community facility. This system brings advantageous to S11 House, same, it could become a good alternative source to sustain water efficiency spread to more places and users.
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To Conserve Water by Using Rainwater Harvesting System as an Approach to Achieve Sustainable Water Efficiency in S11 House
7.0 References ArchDaily,.
(2013).
S11
House
/
ArchiCentre.
Retrieved
7
June
2015,
from
http://www.archdaily.com/313041/s11-house-archicentre/ Conserve-Energy-Future,. (2014). What is Rainwater Harvesting? Rainwater Harvesting Methods and Techniques -
Conserve Energy Future.
Retrieved
7 June 2015, from
http://www.conserve-energy-future.com/methods-of-rainwater-harvesting.php Ferguson, D. (2014). Rainwater harvesting: using the weather to pay your bills. the Guardian. Retrieved
7
June
2015,
from
http://www.theguardian.com/lifeandstyle/2014/jul/22/rainwater-harvesting-using-theweather-to-pay-your-bills Forestsforwatersheds.org,. (2015). Watershed Forestry Resource Guide - Using Trees To Reduce
Stormwater
Runoff.
Retrieved
6
June
2015,
from
http://forestsforwatersheds.org/reduce-stormwater/ Goel, R. and Patel, V. (2015). 10. Measures for Water Conservation and Improvement in Water Quality.
[online]
Available
at:
http://portal.unesco.org/geography/fr/files/6192/11690988831Accepted_Papers__1.pdf/Accepted%2BPapers%2B-%2B1.pdf [Accessed 8 Jun. 2015]. Gupta, A. (2015). CHAPTER 2 METHODS OF HARVESTING RAIN WATER. [online] RAINWATER
HARVESTING
SYSTEM.
Available
at:
http://wiki.iricen.gov.in/doku/lib/exe/fetch.php?media=iricen_books:rain_water_harvestin g.pdf [Accessed 8 Jun. 2015]. Met.gov.my,. (2015). Malaysian Meteorological Department - Rainfall Trend SP. Retrieved 26 May
2015,
18 | A R C 2 2 1 3 / 2 2 3 4 A s i a n A r c h i t e c t u r e
from
To Conserve Water by Using Rainwater Harvesting System as an Approach to Achieve Sustainable Water Efficiency in S11 House
http://www.met.gov.my/index.php?option=com_content&task=view&id=123&Itemid=135 9 Program, C. (2015). Stormwater Runoff - Chesapeake Bay Program. Chesapeakebay.net. Retrieved
6
June
2015,
from
http://www.chesapeakebay.net/issues/issue/stormwater_runoff S11house.com,. (2015). S11 House - Malaysia’s first GBI Platnum (CVA) rated house. Retrieved 6 June 2015, from http://www.s11house.com/# Sandiego.gov,. (2015). Rainwater Harvesting Information | Public Utilities: Water. Retrieved 6 June 2015, from http://www.sandiego.gov/water/conservation/rainwater.shtml Study, S. (2015). Sustainability of Rain Water Harvesting System in Terms of Water Quality: A Case
Study.
[online]
Academia.edu.
Available
at:
http://www.academia.edu/7764706/Sustainability_of_Rain_Water_Harvesting_System_i n_Terms_of_Water_Quality_A_Case_Study [Accessed 7 Jun. 2015]. Syabas.com.my, (2015). Water Bill F.A.Q » Syarikat Bekalan Air Selangor Sdn. Bhd. (1-800-885252).
[online]
Available
at:
http://www.syabas.com.my/consumer/water-bill-faq
[Accessed 8 Jun. 2015]. Thompson, A. (2015). Rainwater Harvesting · Waterwise. Waterwise.org.uk. Retrieved 6 June 2015, from http://www.waterwise.org.uk/pages/rainwater-harvesting.html Wise,
B.
(2015).
Retrieved
6
June
2015,
from
https://www.rainbird.com/landscape/resources/webinars/Rainwater%20Harvesting.pdf
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