[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.