What is in Melbourne tap water

Melbourne's mains water is safe to drink, and it is among the least processed big-city supplies in the world because most of it comes from forested catchments closed to the public. It is disinfected with chlorine, it is fluoridated, and it is soft. Filtering it at home is about taste, smell and sediment, not about safety.

Where it comes from

Melbourne's water is collected from protected catchments in the ranges east and north east of the city. Those catchments are closed forest, which is why the supply needs so little treatment compared with cities that draw from rivers running through farmland.

That is the reason a Melbourne filter conversation is a different conversation from a Sydney or Adelaide one, and a very different one from the United States, where most of the marketing in this category comes from.

What is added to it

Chlorine, for disinfection. Melbourne's supply carries free chlorine rather than chloramine. That matters for filtration, because free chlorine is straightforward for a carbon filter to remove, and it is the part of the treatment you can smell. It is why a glass of water can smell faintly of a swimming pool on a hot day, and why that smell is stronger in some suburbs than others.

Fluoride, for dental health. Added across Victoria under state health policy. A main line filter does not remove fluoride, and this site does not claim it does. A reverse osmosis system at the sink reduces it substantially. If fluoride is your reason for filtering, say so and we will tell you plainly what each system does rather than sell you the wrong one.

What is not added, and gets in anyway

Water leaves the treatment plant clean and then travels through mains, some of them old, to reach your house.

Sediment and rust. Mains repairs, hydrant flushing, a burst nearby or a change in flow direction can all lift material that has settled in the pipe and push it to your tap, and it can run brown or gritty for a day afterwards. Sediment and rusty water.

Your own plumbing. Old galvanised pipe inside the house, a corroding hot water system, or a long run of pipe that sits unused adds its own taste. A main line filter sits before all of that.

What Melbourne water does not have much of

Hardness. Melbourne's supply is soft. Water softeners are a real product for parts of South Australia, Western Australia and pockets of northern Victoria, and they are not a Melbourne product. If somebody is trying to sell you a softener for a Melbourne house, ask them what hardness reading they are treating.

Heavy sediment load. Compared with a rainwater tank or a bore, the mains supply arrives with very little in it. That is why a Melbourne whole-house system is a taste, smell and appliance-protection purchase, and why the first stage is a washable sediment filter for the occasional slug of grit from mains work rather than a heavy-duty sediment setup.

How to look up your own supply

Your water retailer publishes an annual drinking water quality report covering the area it supplies, and you can request a result for your own address. In greater Melbourne the retailers are Greater Western Water, South East Water and Yarra Valley Water, and the catchments and bulk supply are Melbourne Water's. Which one you are with is on your water bill.

If something has changed at your tap recently, that is the first call to make, before you buy anything. A burst main or a scheduled flush is a free explanation, and a filter bought to solve a problem that fixes itself in two days is a bad purchase.

So what does a filter actually change