Why is my tap water brown?

Why brown tap water happens

Tap water is normally clear, but PUB says it may very occasionally look discoloured or contain particles (PUB's drinking water FAQs). Causes include maintenance work, such as routine cleaning of water tanks, flushing of service pipes in buildings and testing of fire hydrants, and the internal fittings and installations in homes.

PUB's FAQs list these specific causes of discoloured water (PUB):

• A corroded water heater. The iron tank and other parts of a storage type hot water heater can corrode at the end of its service life or because of quality issues.
• Corroded pipes and fittings. Service water pipes and fittings that have corroded can discolour the water.
• Stagnant water. Water can sit in service pipes that are used infrequently, for example while owners are away on holiday.
• A watermains leak. Heavy drawoff from a leak in the water mains can stir mineral sediments back into the water.

Maintenance work and a mains leak start outside your flat. A corroded heater, corroded pipes and fittings, or water left standing start inside your home. The steps below help you work out which applies.

What to do first

For discoloured water in Singapore homes, PUB's FAQs give a short routine you can follow straight away (PUB). Work through it in order.

1. Run the taps. Run the taps and flush any water tanks in your home until the water runs clear.
2. Hold off on laundry. Avoid using the water for laundry or other purposes until it is clear.
3. Check where it comes from. See whether the colour comes from a single appliance, or only from the hot water taps or showers. PUB says that could indicate a faulty hot water heater or appliance (PUB).
4. Call PUB if it does not clear. If the water has not cleared after 10 to 15 minutes, call PUB's hotline, 1800-CALL-PUB (PUB).

The full number is 1800-2255-782. PUB's Call Centre runs 24 hours and is toll-free, though airtime charges apply to mobile calls to 1800 lines. For non-urgent water supply issues, PUB also has an online feedback form (PUB's contact page).

Is it safe to drink?

Not until it runs clear. PUB's answer on whether discoloured water is safe is to let the tap run until the water is clear before drinking. If it is not clear after 5 to 10 minutes, call 1800-CALL-PUB (PUB's FAQs). PUB gives that time in its drinking advice; the 10 to 15 minutes in the steps above is its time for clearing discoloured water.

Milky or cloudy water is different. PUB says dissolved air can make tap water look milky. The tiny bubbles disappear after a few minutes and the water is still safe. If the milky look persists, call 1800-CALL-PUB (PUB).

For everyday drinking from the tap, see our post on whether tap water is safe to drink.

When the cause is in your home

If the source is within your premises, for example a faulty or corroded water tank, PUB advises you to replace or repair the appliances or pipes (PUB's FAQs). To prevent a repeat, PUB suggests corrosion resistant materials for service pipes, and replacing appliances at signs of corrosion or once they pass the service life the supplier states.

If you have a rusty water tap, or brown water that returns after flushing, corroded service pipes and fittings are one cause PUB lists (PUB). A licensed plumber can check the pipes for you.

If only the hot taps are affected, start with the water heater. PUB says discoloured water only from the hot taps or showers could indicate a faulty heater, and lists corrosion of the iron tank in a storage type heater as one cause (PUB). Ask the maker or a licensed plumber to check it. If it needs replacing, the cost depends on the job; see our water heater replacement cost guide.

Who fixes what

If the source is in PUB's water mains, PUB isolates it, flushes the mains and provides temporary water, such as water bags, or water wagons in more serious cases (PUB's FAQs).

Inside your flat, pipe repairs are licensed plumber work. Under PUB's rules, repairing or replacing water pipes is regulated work for a PUB Licensed Plumber. Handymen may do only PUB's simple plumbing works, such as replacing a tap, mixer, showerhead or shower hose, or any pipe between a stop valve and an instantaneous water heater. Other water pipes, and pipework for a storage water heater, need a PUB Licensed Plumber (PUB's Plumbing Works page).

If you also find a leak, HDB says to shut the stopcock at the PUB water sub-meter to cut the water supply, and to engage a licensed plumber for repairs where necessary (HDB). Our leak repair page covers that job. Prices depend on the job, so check plumbing costs and compare plumbers.

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