How does your city treat drinking water?

02/01/2020 Sidrah Ahmad

City water treatment is vital for providing a safe, drinkable supply to local populations. Utility companies have responsibility for ensuring they treat the municipal supply, so we feel confident drinking from the tap, while authorities monitor the water quality to check that potential contaminants never pose a threat to human health. Water passes through several treatment stages before it ever reaches your home — with filtration and purification getting rid of a range of pollutants, including heavy metals, organic compounds, and human-made toxins.

Your water must go through a complex system of treatment stages to remove impurities, bacteria, and parasites, and make it drinkable. Moreover, utility companies have to treat the water in such a way that it stays clean and odorless as it trickles its way into your office or home. We fill a glass from the tap, then assume it is safe enough to drink but have you ever thought about how your local water supply is treated? How much do you know about the specific processes your water passes through to make it fit for human consumption?

Why do we need water treatment?

Local water companies get their supply from surface water and ground water, which are open to environmental contaminants and a liable to become polluted.

Surface water includes lakes, rivers, and streams. Australians can rely on surface water for as much as 75% of the municipal supply, depending on the state in which you live. Rainwater runoff from farms can wash nitrates and pesticides into rivers and waterways, which can find their way into the drinking water supply. Groundwater sources include aquifers and underground lakes that collect rain that has seeped through cracks and pores before the water collects in pockets between the rocks that sit deep within the ground. Utility companies tap groundwater where there isn’t enough supply of surface water to service the community.

As water trickles through rocks, it can take heavy metals like arsenic into underground aquifers. In South Australia, the EPA recently proposed a permanent ban on local residents using groundwater owing to contamination from uranium and other degreasing chemicals. Across Australia, there have been a total of 106 reported groundwater contamination incidents stemming from both natural and human-made sources, including the release of sewage effluent, illustrating the extent of the known risks.

The state Environmental Protection Agency supervises the quality of the public water supply across each Australian region, taking guidance from the Environment Protection (Water Quality) Policy 2015 to track and enforce water quality standards.

How is water treated?

Water goes through a rigorous treatment process to remove any compound that could pose a threat to our health. This treatment process involves four stages that make your water ‘clean enough to drink.'

1. Coagulation and Flocculation

This uses chemicals that bind with other waterborne compounds to form larger particles, which creates a solid mass called floc.

2. Sedimentation

As floc is denser than water, it drifts to the bottom of the water treatment tank during a sedimentation process, settling in a removable layer.

3. Filtration

Once the suspended floc has been removed, the residual clear water is passed through sand, gravel, or charcoal filters that take out dissolved particles, parasites, bacteria, viruses, and toxic chemicals.

4. Disinfection

The final water treatment stage is disinfection with chlorine. This process not only removes remaining pathogens, but keeps the water supply clean as it passes through the pipeline.

The benefits and pitfalls of water treatment

While all municipal water supplies pass through a standard treatment process, your water may undergo different levels of treatment depending on where your water comes from. For example, surface water needs a higher level of coagulation, sedimentation, and filtration than groundwater because water taken from lakes, rivers, and streams is likelier to contain more sediment and higher levels of contaminants than naturally-filtered groundwater.

Every water supply also requires disinfection to guarantee the water becomes and remains safe to use. Typically, disinfection uses chlorination, chloramines, ozone, or ultraviolet light.

Chlorine is efficient at eliminating microbial pathogens, which is why 64% of US community water treatment systems use chlorine as a disinfectant. However, some consumers don’t like the smell or taste of chlorinated water. Studies suggest bi-products of chlorine disinfection could increase the risk of cancer, including bladder and rectal by up to 93%.

The risks associated with chlorine have moved utility companies to look at alternative disinfectant options. Ozonation is often to remove pathogens from the treated water supply. However, chlorine is still required as ozone cannot keep a supply contaminant-free once it has left the treatment plant.

Another disinfection option is ultraviolet light: UV from a lamp destroys viruses and bacteria.

Is water treatment always successful?

Despite the strict standards and rigorous supervision, water treatment isn’t always effective. In Western Australia, nitrate contamination has become such an issue that the Western Australia Water Corporation has released a recommendation that infants under 3-months old avoid drinking the water altogether as nitrates are particularly harmful to young babies.

Elsewhere in Australia, carcinogenic chemicals used in firefighting have found their way into local water supplies leading to over 40,000 residents suing the government in what is the biggest class action lawsuit in the nation’s history.

Water dispensers guarantee clean, purified drinking water

There’s only one way to ensure your water supply is entirely safe — that is, to install a filtration and purification system where you fill your glass.

A water dispenser uses an array of technologies to ensure your water supply is purified, starting with high-performance carbon filtration that removes chlorine, lead and pesticides. This is followed by microbiological purification using UV light to eliminate 99.9999% of all germs (including E. Coli, Salmonella and Hepatitis), guaranteeing pure water thanks to a process that’s 100% chemical-free.

If you’re ever unsure whether your local water supply is fit for consumption, contact Waterlogic, and our expert customer service agents will recommend the perfect point-of-use water dispenser to protect your office from water contaminants.