Thursday, 31 October 2019

[Draft 2] Technical Report


  1. Background

This report has been developed as a response to a Call For Proposals (CFP) to developing solutions for engineering problems. 
According to World Health Organisation(WHO, 2019), safe and readily available water has always been one of the key goals globally. The article stated that the ‘United Nation(UN) General Assembly explicitly recognized the human right to water and sanitation’. This shows a huge emphasis had been placed on water quality. The consumption of water in Singapore is approximated 430 million gallons of water per day (The Straits Times, 2018). In the same article, it was stated that there are four sources of water supply in Singapore: local catchment water, imported water, NEWater and desalinated water; they each can only provide up to 10%, 60%, 30%, 25% of the water needs of the entire island country respectively.
Singapore provides one of the highest quality of municipal water supply in its surrounding region. The quality of water is kept within the World Health Organization (WHO) drinking water guidelines and US Environmental Public Health (Quality of Piped Drinking Water) Regulations 2008. According to Singapore’s water agency Public Utilities Board (PUB, 2018), the quality of supplied water is assured through routine chemical and bacteriological water samples collected daily across the island. PUB also monitors the water quality at every stage of their service reservoirs and water treatment plants through online-sensors before dissemination to the public. 
Despite these efforts to ensure a stable supply of clean water, PUB (2018) has stated that water from the taps can sometimes still appear brownish. They stated that this is due to unforeseen circumstances such as pipe leakages or flushing of fire hydrants, where the resulting change of direction or rate of flowing water can cause the resuspension of excess iron, manganese and other dissolved metal deposits that have accumulated over time inside the underground municipal water pipelines. Consumption of water that contain excess iron and manganese could leave a negative impact in aspects of neurological as well as physically. According to Passaic Bergen Water Softening (2017), water with excessive amounts of dissolved minerals such as iron and magnesium can have negative effects on your skin. They can damage healthy skin cells, which can lead to wrinkles. In addition, water with iron doesn’t blend well with soap. This, in turn, can lead to skin problems such as acne or eczema. At the same time, T&H Blog (2015) states that long term exposure to high concentrations of manganese in drinking water is associated with toxicity to the nervous system, producing a syndrome called Manganism.
According to Xue (2014), thousands of households in the Punggol estate were affected by discoloured tap water caused by the mineral sediments in a water pipeline stirred up during valve operations on a portable water pipe along Tampines Expressway. The water in the mains were only resolved by the next morning after PUB and Pasir Ris-Punggol Town Council subsequently flushed the affected water tanks, although the problem has been solved but the residents were still advised to run their taps until the water is clean. (This leads to wastage of water and also inconvenient for the residents.) [link back to water quality]  
Moreover, the routine tests that PUB conduct are only indicative of the water quality in the PUB pipes upstream. There is currently no way building owners/facility managers(FMs) can be aware of any change in quality of water once it enters their premises. Therefore, the users in household will be the first to find out the discolouration instead of the FMs. This will eventually lead to disputes between the household users and FMs, which are supposed to be prevented in the first place.

1.1 Current Situation

In Singapore, when potable water is supplied to a private building, it is done through a ferrule connection that splits off from the main underground municipal water pipe. The water is then drawn towards the building through the use of a pump, before the pipe leads into a water tank. This water tank then stores and distributes water in a network of smaller service pipes directly to a user’s taps when it is opened. The capacity of the water tank is usually built with at least 24 hours of usage volume as reserve water supply if water supply is ever disrupted.
In the event of discoloured water, once water exiting the taps have become brownish, it would indicate that the brownish water has already entered the water tank and diffused throughout the entire water supply system in the building. The entire capacity of the tank (~24 hours of reserve supply) is rendered unusable. Currently, the only process to remove the polluted water involves the halting of water supply, then flushing the contents of the entire water tank is only completed with the refilling of fresh water with all the water ticking through the tariff meter. Apart from the wastage of water, it would be expensive for facility managers to deal with the aftermath should brownish water ever enter their water tanks.
There should be preventive/corrective measures implemented so that facility managers can effectively handle influx of such unpredictable brownish water from reaching the end-users.

1.2 Problem Statement

In the upcoming Singapore Institute of Technology @ Punggol campus, potable water supplied should always be within World Health Organisation (WHO) clean drinking standards at all times.
However, the FM of SIT have no way to know should any fluctuations in water quality occur, and thus have no way to be prepared to deal with them in time.

1.3 Purpose Statement

The purpose of this report is to propose to SIT to install a safeguard measure in the downstream potable water supply service pipeline as an early indicator to prevent potential contamination of the water tanks in SIT@ Punggol.

  1. Proposed Solutions

2.1 Installing active water sensors (Solution 1) 

The current water system in most buildings are unimpeded pipelines that directly link to the building’s water tanks. Should there be any dip in water quality, the discoloured water will directly flow into the water tank.
The team proposes the installation of an active water sensor directly onto the main water pipe prior to the pump. This allows early detection in the case of a supply influx of lower quality water before they even reach the pumps. With the ability to instantaneously detect these fluctuations, the pump can be set to automatically withhold its operation. A solenoid-controlled pilot valve can then be programmed to shut off so that the brownish water do not travel any farther. This prevents dirty water from ever reaching the water tanks. It would nullify the need to wash and flush the water tanks, saving time and reduce the wastage of water in the occurrence of the inevitable batch of discoloured water.

2.2 Water purifier/treatment system installed in water tanks (Solution 2)


Centers for Disease Control and Prevention (CDC,2009) states that water contamination can occur even in the safest tap water supply. The article also states that one of the causes of contamination could be the ‘improperly maintained’ pipeworks. The idea of installing water purifier/treatment system in water tanks is to ensure that water quality is maintained clean when it is being drawn out from water tank. In the event of contamination of water supply, water treatment system can be in place to purify the water/keep the contamination to the bare minimal. Some of the common methods of water treatment system includes filtration, disinfection, distillation, water purifiers or a combination of the mentioned methods. The water treatment system to rectify the issue that was mentioned in this report can include:

2.2.1 Ultra-violet(UV) purification

According to waterpurifier.org, UV water purification system consists of a UV light source that produce a strong intensity radiation that can eliminate 99.99% of bacteria and render any harmful microbes sterile.

2.2.2 Ozone water purifiers

According to brighthubengineering.com, ozone water purifiers are a smaller version of those used in municipalities. Ozone water purifiers are located at the water intake point between the tank and the intake to ensure the water supply are disinfected before entering the water tank. Ozone water purifiers work by oxidizing most bacteria and bonds with many dissolved materials that result in them precipitate to the bottom of the water. Ozone water purifiers is effective in removing iron and manganese as well as freeing chlorine to kill even more microbes if used in a multiple step systems.

2.3 Installing portable water treatment plant 


       Our team’s third solution is the implementation of portable water treatment plant. A portable water treatment plant is generally smaller than a normal water treatment plant. So it can be installed right next to a building’s water tank itself. It will either always treating the water in the water tank or treat the water when it’s dirty from pipe leakage etc. It can act as a backup solution to the first solution. Although the water treatment plant affects the water pressure due to the filtration process. Fortunately, there is a water pump after the filtration process to allow the water to travel to each household.

  1. Benefits of proposed solutions

3.1 Benefits for Solution 1 


To preserve the water quality, it is important to monitor the water parameters. 
With the installation of the active water sensor, it minimizes the effect on measurement accuracy from contamination and improves the accuracy at higher turbidites and the tolerance of a range of particle sizes. 

3.2 Benefits for Solution 2 


Water treatment system is a combination of different components that complement each other to achieve the optimal result. Water treatment system helps to keep the water quality within the drinking standard by removing most of the impurities in the scope of micro-organism. Water is separated from unwanted substance once it has been purified. Water treatment system does not require too much humans intervene as to control how it works. Water treatment systems are able to obtain the main objective of keeping the water quality to be within the drinking standard of WHO/prevent people from drinking contaminated water.

  1. Drawbacks of proposed solution

4.1 Drawbacks for Solution 1

          A sole electrical sensor acting as a preventive measure to ensure a constantly-clean water supply means that its reliability is a huge concern. There would be a need for regular maintenance for the sensor; it might relate to increased cost for the FM of SIT@Punggol if 3rd party contractors were to be hired for regular maintenance on an ad-hoc basic
          A guarantee-contract with the sensor manufacturer for regular scheduled maintenance would be recommended, as long-term contracts tend to be cheaper in the long run.

4.2 Drawback for Solution 2

         Water treatment system requires all components to be in working condition. In event of spoilt/damaged components, water treatment system would not be as effective in acquiring its objective of purifying water. Considerable amount of energy consumption would be required to allow water treatment system to run at all times as a preventive measure against contaminated water. Constant check schedule has to be made to identify if the water treatment system is working. The drawbacks of water treatment system can result in a worse water quality if maintenance is not done consistently. Hence, daily maintenance is required for water treatment system to work efficiently and effectively. Water treatment system might be considered an ‘overkill’ as a preventive measure contamination in water due to leakage in pipes since the water supply has already been treated before.




Tuesday, 29 October 2019

[Draft 1] Technical Report

Background
This report has been developed as a response to a call for proposals to developing solutions for engineering problems. 
Singapore now constitutes of 4 water supply sources which contributed to the usage of 400million gallons of water in Singapore, namely local catchment water, imported water, NEWater and desalinated water (The Straits Times, 2018). Currently, local catchment water, imported water, NEWater and desalinated water each can only meet 10%, 60%, 30%, 25% of the Singapore water needs respectively. Our daily water consumption is based on the 4 water sources. Household water supply in Kulai are cut off due to the ‘ammonia-contaminated water flowing into the Sayong River – one of the creeks that supply raw water to the Johor River’. Although Singapore water supply was not affected, this could be one of the potential causes that can affect water quality in the water supply source. 
Singapore provides one of the highest quality of municipal water supply in its surrounding region. The quality of water is kept within the World Health Organization (WHO) drinking water guidelines and US Environmental Public Health (Quality of Piped Drinking Water) Regulations 2008. According to Singapore’s water agency Public Utilities Board (PUB, 2018), the quality of supplied water is assured through routine chemical and bacteriological water samples collected daily across the island. They also monitor the water quality at every stage of their service reservoirs and water treatment plants through online-sensors before dissemination to the public. 
However, PUB (2018) have stated that water from the taps can sometimes appear brownish due to the change of direction or rate of water flowing in municipal water pipes from occurrences such as pipe leakages or flushing of fire hydrants. The discolouration is due to the resuspension of excess iron, manganese and other dissolved metal deposits that accumulate over time inside the underground municipal water pipelines.
There had been cases where drinking water supply being contaminated by a corpse in one of the water tanks (Asiaone, 2011). ‘A 43-year-old home-maker, Mrs Goh, said that she saw white bubbles when bathing her children. Her son could be affected by the water as he had sensitive skin, she said.’ Residents still use the water supply despite knowing there is discolouration in the water quality. 
According to Passaic Bergen Water Softening (2017), water with excessive amounts of dissolved minerals such as iron and magnesium can have negative effects on your skin. They can damage healthy skin cells, which can lead to wrinkles. In addition, water with iron doesn’t blend well with soap. This, in turn, can lead to skin problems such as acne or eczema.
Moreover, the routine tests that PUB conduct are only indicative of the water quality in the PUB pipes upstream. There is currently no way building owners/facility managers(FMs) can be aware of any change in quality of water once it enters their premises.
Current Situation
In Singapore, when potable water is supplied to a private building, it is done through a ferrule connection that splits off from the main underground municipal water pipe. The water is then drawn towards the building through the use of a pump, before the pipe leads into a water tank. This water tank then stores and distributes water in a network of smaller service pipes directly to a user’s taps when it is opened.
This would mean that once water exiting the taps have become brownish, it is indicating that the brownish water has already entered the water tank and diffused throughout the entire water supply system in the building. The process to remove the polluted water involves the halting of water supply, then flushing of the entire water tank is only completed with the refilling of fresh water with all the water ticking through the tariff meter. Apart from the wastage of water, it would be expensive for facility managers to deal with the aftermath should brownish water ever enter their water tanks.
There should be preventive measures implemented so that facility managers pre-empt against the initial entrance of such unpredictable brownish water from enter their water tanks.

Problem Statement
In the upcoming Singapore Institute of Technology @ Punggol campus, potable water supplied should always be within World Health Organisation (WHO) clean drinking standards at all times.
However, the FMs have no way to know should any fluctuations in water quality occur, and thus have no way to be prepared to deal with them in time.
Purpose Statement
The purpose of this report is to propose to SIT to install active water quality sensors in the downstream potable water supply service pipeline as an early indicator to prevent potential contamination of the water tanks in SIT@ Punggol.

Sunday, 13 October 2019

[Draft 3] Summary_Reader's Response: Developing Sustainable Infrastructure in New Cities

In the article “Developing sustainable infrastructure in new cities”, Cho (2014) expressed the importance of sustainable infrastructure in a metropolitan setting and identified key areas in determining how infrastructure can add value to the community. She discussed how due to economic-driven developments in new cities being affected by metropolitan challenges, enhancements in functionality and durability of infrastructure are necessary to keep up with these developments. As an Impact King Abdullah Economic City (KAEC) Fellow, Cho also explained how she intended to apply the Envision sustainability rating system as an impartial guideline to evaluate sophisticated infrastructure development. The article listed two highways built in Mexico and Peru that followed the Envision framework and highlighted how they both have had economic, social and environmental benefits. In the course of her Fellowship, Cho also proposed to provide an Envision evaluation on a major planned road that is expected to be a main entry point and arterial road in King Abdullah Economic City”, to satisfy KAEC’s extensive sustainable infrastructure development. She insisted that the Envision framework will benefit not only KAEC, but new cities globally too. 

Cho is right by saying that the use of the Envision rating system would greatly benefit a new city. The green development of its roads particularly would benefit a new city societally and ecologically, encourage the use of sustainable materials, and also as a result, reduce its maintenance problems in the long run.

It was observed that in many cities, urbanisation takes place at the expense of rural areas, which exacerbates the difference socially, economically and environmentally behind urban areas (Zhang, Wu, Skitmore, Jiang, 2015). Therefore, research had been done to explore sustainable development between urban and rural areas through structured construction of public infrastructure and roads. In the original article, Cho believes that the use of Envision rating system would serve as a direction for these improvements to take place. According to Georgoulias (2015), the categorical interpretation in the Envision rating system not only provides clear direction for engineers to strive for well-rounded solutions while considering the needs of communities, but also consider the preservative nature of planned sustainable development and how their conservation efforts might result in the future.

The Envision Rating system also encourages the use of sustainable materials.
There are categories within the rating system that award points based on the use of recycled or reclaimed material. This helps to minimise resource consumption by avoiding materials originating from distant sources, and reduces over-dependence on scarce and natural resources. Muralikrishna and Manickam (2017) stated that in the long term, the responsible use of natural resources at present will help to make sure that resources remain available for prospective industrial developments further ahead.

The encouraged use of sustainable materials can also beneficially relieve maintenance issues. For example, the usage of conventional asphalt— which, apart from its strength and durability, are usually impervious and hydrophobic— can result in flooding in the event of heavy downpour.  Molenaar (2013) showed that the use of sustainable porous asphalt however, allows stormwater to sift through its surface into the soil subsurface. The pervious nature of the material reduces the risk of such floodings. Cho stated how the integration of sustainable techniques into highway constructions in Peru and Mexico had welcomed many benefits. This holds even truer as sustainable designs can concurrently reduce the risk of damage on roads. In many cities, their municipal water supply pipelines run underneath or along its network of roads. Dislodgement and cracking of these water pipes can occur from unsustainable design at construction (Molenaar, 2013). The resulting water leakages can form multiple potholes under the surface of their roads (Vijetha, 2016). In contrast, according to Moe and Handojo (2017), the sustainable use of rubberised bitumen for road pavement introduces a trait of flexibility on the surface. This material absorbs some of the shearing and bending induced from its surrounding movements. This greatly reduces the frequency of water leakages arising from the inflexibility of conventional asphalt.

Roads are the arteries of a city, where not only resources flow in-and-out for its economy to flourish, but also for its citizens back-and-forth to connect with one another. Apart from the economic, social and environmental benefits that Cho emphasised accompanying the use of a structured guideline such as the Envision rating system, sustainable road constructions can provide reduced maintenance upkeep. Engineers can hopefully be influenced to follow the Envision guidelines to seek the use of greener materials, which would eventually improve a city's environmental responsibility.



References:

Cho, H. (2014). Developing sustainable infrastructure in new cities.
Retrieved from: https://newcities.org/evaluating-sustainable-infrastructure-development-new-cities/

Georgoulias, A. (2015, February). The Envision Rating System for Sustainable Infrastructure: Development, Applications, and the Potential for Lebanon. Retrieved from https://pdfs.semanticscholar.org/a62a/b52bec6923442f3661055d045ebb78e62ed9.pdf

Moe, A. L., Handojo, D. U. (2017). Crumb rubber modified bitumen in open graded wearing course of flexible pavement. Open Journal of Civil Engineering, 7(2), 166-167. doi: 10.4236/ojce.2017.72010

Molenaar, A. (2013). Durable and sustainable road constructions for developing countries. Retrieved from: http://www.sciencedirect.com/science/article/pii/S1877705813003615

Muralikrishna I. V., Manickam, V. (2017, January 23). Environmental Management: Science and Engineering for Industry. Elsevier Inc. Retrieved from: https://www.sciencedirect.com/science/article/pii/B9780128119891000026

Zhang, X., Wu, Y., Skitmore, M., Jiang, S. (2015, November 16). Sustainable infrastructure projects in balancing urban–rural development: towards the goal of efficiency and equity. Journal of Cleaner production, 107(1), 445-454. doi: 10.1016/j.jclepro.2014.09.068

Monday, 7 October 2019

[Draft 2] Summary_Reader's Response: Developing Sustainable Infrastructure in New Cities

In the article “Developing sustainable infrastructure in new cities”, Cho (2014) expressed the importance of sustainable infrastructure in a metropolitan setting and identified key areas in determining how infrastructure can add value to the community. She discussed how due to economic-driven developments in new cities being affected by metropolitan challenges, enhancements in functionality and durability of infrastructure are necessary to keep up with these developments. As an Impact King Abdullah Economic City (KAEC) Fellow, Cho also explained how she intended to apply the Envision sustainability rating system as an impartial guideline to evaluate sophisticated infrastructure development. The article listed two highways built in Mexico and Peru that followed the Envision framework and highlighted how they both have had economic, social and environmental benefits. In the course of her Fellowship, Cho also “aims to provide an Envision evaluation on a major planned road that is expected to be a main entry point and arterial road in King Abdullah Economic City”, to satisfy KAEC’s extensive sustainable infrastructure development. She believes that the Envision framework will benefit not only KAEC, but new cities globally too. 

Cho is right by saying that the use of the Envision rating system would greatly benefit a new city. The green development of its roads particularly would benefit a new city societally and ecologically, encourage the use of sustainable materials, and also as a result, reduce its maintenance problems in the long run.

It was observed that in many cities, urbanisation takes place at the expense of rural areas, which exacerbates the difference socially, economically and environmentally behind urban areas (Zhang, Wu, Skitmore, Jiang, 2015). Therefore, research had been done to explore sustainable development between urban and rural areas through structured construction of public infrastructure and roads. In the original article, Cho believes that the use of Envision rating system would serve as a direction for these improvements to take place. According to Georgoulias (2015), the categorical interpretation in the Envision rating system not only provides clear direction for engineers to strive for well-rounded solutions while considering the needs of communities, but also "rewards restorative efforts that exceed traditional sustainability performance".

The Envision Rating system also encourages the use of sustainable materials.
There are categories within the rating system that award points based on the use of recycled or reclaimed material. This helps to minimise resource consumption by avoiding materials originating from distant sources, and reduces over-dependence on scarce and natural resources. Muralikrishna and Manickam (2017) stated that in the long term, the responsible use of natural resources at present will help to make sure that resources remain available for "sustained industrial growth far into the future".

The encouraged use of sustainable materials can also beneficially relieve maintenance issues. For example, the usage of conventional asphalt— which, apart from its strength and durability, are usually impervious and hydrophobic— can result in flooding in the event of heavy downpour.  Molenaar (2013) showed that the use of sustainable porous asphalt however, allows stormwater to sift through its surface into the soil subsurface. The pervious nature of the material reduces the risk of such floodings. Cho stated how the integration of sustainable techniques into highway constructions in Peru and Mexico had welcomed many benefits. This holds even truer as sustainable designs can concurrently reduce the risk of damage on roads. In many cities, their municipal water supply pipelines run underneath or along its network of roads. Dislodgement and cracking of these water pipes can occur from unsustainable design at construction (Molenaar, 2013). The resulting water leakages can form multiple potholes under the surface of their roads (Vijetha, 2016). In contrast, according to Moe and Handojo (2017), the sustainable use of rubberised bitumen for road pavement introduces a trait of flexibility on the surface. This material absorbs some of the shearing and bending induced from its surrounding movements. This greatly reduces the frequency of water leakages arising from the inflexibility of conventional asphalt.

Roads are the arteries of a city, where not only resources flow in-and-out for its economy to flourish, but also for its citizens back-and-forth to connect with one another. Apart from the economic, social and environmental benefits that Cho emphasised accompanying the use of a structured guideline such as the Envision rating system, sustainable road constructions can provide reduced maintenance upkeep. Engineers can hopefully be influenced to follow the Envision guidelines to seek the use of greener materials, which would eventually improve a city's environmental responsibility.



References:

Cho, H. (2014). Developing sustainable infrastructure in new cities.
Retrieved from: https://newcities.org/evaluating-sustainable-infrastructure-development-new-cities/

Muralikrishna I. V., Manickam, V. (2017) Environmental Management: Science and Engineering for Industry. Retrieved from: https://www.sciencedirect.com/science/article/pii/B9780128119891000026

Zhang, X., Wu, Y., Skitmore, M., Jiang, S. (2015, November 16) Sustainable infrastructure projects in balancing urban–rural development: towards the goal of efficiency and equity. Journal of Cleaner production. Retrieved from: https://www.sciencedirect.com/science/article/pii/S0959652614010075

Georgoulias, A. (2015, February). The Envision Rating System for Sustainable Infrastructure: Development, Applications, and the Potential for Lebanon. Retrieved from https://pdfs.semanticscholar.org/a62a/b52bec6923442f3661055d045ebb78e62ed9.pdf
Moe, A. L., Handojo, D. U. (2017). Crumb rubber modified bitumen in open graded wearing course of flexible pavement. Open Journal of Civil Engineering, 166-167.

Molenaar, A. (2013). Durable and sustainable road constructions for developing countries. Retrieved from: http://www.sciencedirect.com/science/article/pii/S1877705813003615

Thursday, 3 October 2019

[Draft 1] Summary_Reader's Response: Developing Sustainable Infrastructure in New Cities

In the article “Developing sustainable infrastructure in new cities”, Cho (2014) expressed the importance of sustainable infrastructure in a metropolitan setting and identified key areas in determining how infrastructure can add value to the community. She discussed how due to economic-driven developments in new cities being affected by metropolitan challenges, enhancements in functionality and durability of infrastructure are necessary to keep up with these developments. As an Impact King Abdullah Economic City (KAEC) Fellow, Cho also explained how she intended to apply the Envision sustainability rating system as an impartial guideline to evaluate sophisticated infrastructure development. The article listed two highways built in Mexico and Peru that followed the Envision framework and highlighted how they both have had economic, social and environmental benefits. In the course of her Fellowship, Cho also “aims to provide an Envision evaluation on a major planned road that is expected to be a main entry point and arterial road in King Abdullah Economic City”, to satisfy KAEC’s extensive sustainable infrastructure development. She believes that the Envision framework will benefit not only KAEC, but new cities globally too. Cho is right by saying that sustainable developments based on a carefully-reviewed framework used in the green development of a new city's roads would help to pave its foundation, which would also reduce future problems in the long run.

Roads are the arteries of a city, where not only resources flow in-and-out for its economy to flourish, but also for its citizens back-and-forth to connect with one another. It is how a city can begin to prosper, taking in trade and like nutrients from a root. Without a stable foundation that sustainable road development provides, a city is bound to waste resources on repairing and maintaining the wear and tear that results thereafter.

The Envision Rating system encourages the use of the materials that are recycled or reclaimed. This can, at the same time, be sustainable and benefit the community on a physical aspect. For example, the usage of conventional asphalt— which, apart from its strength and durability, are usually impervious and hydrophobic— can result in increased surface run-off in the event of heavy downpour. This can lead to increased risk of flooding at areas with lower elevation. The use of porous asphalt normally containing up to 20% of reclaimed asphalt (Molenaar, 2013) however, allows stormwater to sift through its surface into the soil subsurface. These pervious roads also mean there will be lesser pooling of water on its surface, reducing headlight glare and decreasing the risk of hydroplaning in a vehicle. (Spurling, 2013).

The use of sustainable materials for road paving can also reduce the risk of damage. In many cities, their municipal water supply pipelines run underneath or along its network of roads. The need for road repairs can lead to unexpected and excessive soil settlement in the future, which can dislodge or crack water pipes that run below or beside its length. It is expensive, time-consuming and disruptive to traffic to repair these leakages. Sometimes, these leakages do not even surface and go undetected, leading to water resources being drained off and wasted indefinitely. These water seepages can also eventually form multiple potholes under the surface of their roads. (Vijetha, 2016). The use of rubberised bitumen introduces a trait of flexibility on the roads. This material absorbs some of the bending induced from its surrounding settling. (Moe, 2017). This would greatly reduce the frequency of water leakages due to the inflexibility of conventional asphalt.

In conclusion, the Envision rating system serving as an incentive for responsible road developments the paving of new roads for new cities can concurrently be sustainable and provide benefits beyond just being green. Apart from the economic, social and environmental benefits, green alternatives road constructions do provide improvements on a simpler superficial level as well.



References:

Cho, H. (2014). Developing sustainable infrastructure in new cities.
Retrieved from: https://newcities.org/evaluating-sustainable-infrastructure-development-new-cities/

Moe, A. L. (2017). Crumb rubber modified bitumen in open graded wearing course of flexible pavement. Open Journal of Civil Engineering, 166-167.

Molenaar, A. (2013). Durable and sustainable road constructions for developing countries. ScienceDirect. Retrieved from: http://www.sciencedirect.com/science/article/pii/S1877705813003615

Spurling, H. (2013). Water sensitive urban design for sustainable road development. University of Southern Queensland. Retrieved from: https://eprints.usq.edu.au/24702/1/Spurling_2013.pdf