What is tap water? Is tap water safe to drink?

Every time we turn on a tap in our home, taking a moment to consider the quality of the water that flows out within seconds is one of the most fundamental steps we can take towards a healthy lifestyle. Amidst the hustle and bustle of daily life, many consumers may overlook the immense engineering and chemical processes that lie behind the question of what tap water actually is. Put simply, tap water is raw water sourced from nature that has been treated and delivered to our homes, workplaces and industrial facilities via closed pipework systems. In this comprehensive guide, we will detail the arduous journey of drinking water from reservoirs to our glasses, examine the reliability of tap water, and explore the scientific methods for making your water as healthy as possible.

Clean and drinkable water is not only a basic physiological need today, but also a serious public health issue. Throughout history, civilisations have been built around water sources, and as infrastructure systems have developed, the foundations of modern cities have been laid. However, today, increasing industrial activity, climate change and infrastructure problems can prevent the water flowing directly from the tap from always being of impeccable quality. This is precisely why knowing the composition of the water you consume is the most effective measure you can take to protect your family’s health.

How Is Tap Water Produced and How Does It Reach Our Homes?

Integrating the natural freshwater cycle into our kitchens is a massive undertaking shouldered by local authorities and engineering departments. The collection, settling, purification of water to remove harmful organisms, and pumping it kilometres away requires a system that operates 24 hours a day, 7 days a week without interruption.

Reservoir Filling and Water Resources

The primary source of municipal tap water is generally dams, reservoirs and groundwater reserves located in high-altitude catchment areas. Rainwater and snowmelt are collected in these large reservoirs following a process of filtration and runoff lasting several months. According to data from the Turkish Statistical Institute (TÜİK), people’s dependence on urban infrastructure is extremely high; indeed, the average daily water consumption per person supplied to the drinking water network by local authorities has been recorded at 224 litres. This enormous volume necessitates the regular maintenance of water levels in the reservoirs and the continuous extraction of water from nature in a perpetual cycle.

This collected water is in its raw state and contains silt, clay, plant debris and various microorganisms that have naturally mixed into it. The fact that 1,397 out of Turkey’s 1,399 municipalities provide mains water services, with a coverage rate of 98.6 per cent, clearly demonstrates the extent to which this system serves a wide population. The first stage of this network, which extends from rural areas to metropolitan centres, is always the safe collection of water in the catchment area.

Stages and Disinfection Processes in Water Treatment Plants

Raw water drawn from reservoirs is transported to central water treatment plants before being pumped into the city. According to statistics, 58 per cent of the total 6.2 billion cubic metres of water abstracted from natural sources by local authorities undergoes a rigorous treatment process directly at drinking water treatment works. At these works, the coagulation process is applied first. Special chemicals added to the water cause the invisible suspended solids to clump together and grow in size. The water is then transferred to sedimentation tanks, where the particles, having become heavier, settle to the bottom, thereby physically clarifying the water.

The most critical stage following physical purification is filtration and disinfection. Water passed through fine sand and anthracite filters is purified of any remaining microscopic sediments. Finally, the chlorination stage begins. Chlorine is the most effective defence against bacteria throughout the water’s journey spanning several kilometres. At the plant’s outlet, the water is transformed into a clear and potable form that fully complies with the standards set out in the Ministry of Health’s Regulation on Water for Human Consumption.

Infrastructure Networks and Water Distribution

The crystal-clear water emerging from the treatment plants makes its way to our neighbourhoods, streets and, ultimately, our homes via a vast underground network of pipes. At this stage, transmission pipelines, massive pumps and pumping stations come into play. The security of the network is a process that must be managed with institutional rigour. For example, authorities such as VASKİ, which is responsible for water management in Eastern Anatolia, exert considerable effort to deliver water from its source to the city by isolating it from external factors within closed systems along the transmission lines. However, the wear and tear that occurs over time within these vast underground labyrinths, stretching for kilometres, plays a direct and decisive role in determining the quality of the water.

Is Tap Water Safe to Drink? Is It Safe to Drink Tap Water?

The water supplied to the mains by the water and sewerage authorities of Turkey’s metropolitan municipalities (such as İSKİ and ASKİ) has passed laboratory tests at the point of discharge and has been certified as completely safe. However, the answer to the question ‘Is tap water safe to drink?’ depends not so much on the quality of the water as it leaves the treatment plant, but rather on the environmental factors it is exposed to whilst travelling to your tap at home.

The Impact of Old Pipes, Rust, Scale and Water Tanks

Although the main water mains have generally been upgraded using modern and durable materials, the capillary pipes in the streets or the internal plumbing in older buildings pose a serious risk. Galvanised iron pipes laid decades ago can rust over time, causing heavy metals to leach into the water. Furthermore, cracks along the route taken by the mains water supply can cause unwanted sediment and soil to mix into the water.

Furthermore, water tanks located in the basements or on the roofs of blocks of flats are one of the greatest sources of danger. In tanks that do not undergo regular maintenance and are not cleaned every six months, the growth of algae, the build-up of sludge and the proliferation of bacteria are inevitable. That pristine water emerging from the treatment plant loses all its hygienic properties when left to stand in a dirty water tank, and if consumed, it can lead to serious stomach and intestinal disorders.

Why is the Water Pressure in the Building’s Internal Water Supply System Important?

Another issue that is often overlooked, just as much as quality, is the physical force of water—that is, its pressure. Tap water must have a certain flow rate and pressure as it enters residential properties. As noted by Caleffi, a specialist engineering firm, the ideal mains water pressure for fittings and appliances to function properly within a building’s plumbing system should be maintained between 2 and 3 bar. This pressure balance is a critical parameter that directly affects your water comfort at home.

If the water pressure drops below 1.5 bar, your boiler will fail to ignite, the hot water may suddenly cut out whilst you’re having a shower, or your washing machine may struggle to fill with water. Conversely, when the pressure rises above 4 bar – meaning the mains supply is overloaded – the seals in your pipework may burst, water leaks may occur, and your bills may rise unreasonably due to unnecessary water consumption. Using pressure-reducing valves is the most sensible way to protect your home against these fluctuations.

Table of Effects of Mains Water Pressure

The Potential Harms of Drinking Tap Water Directly

The chlorination of tap water is one of the greatest public health revolutions, having prevented deadly epidemics such as cholera, typhoid and dysentery, which ravaged cities in past centuries. Chlorine protects water against biological threats; fluoride, which occurs naturally in certain regions, supports dental development in children. However, despite all these protective measures, drinking tap water straight from the tap can carry certain hidden health risks.

The most prominent complaint is the strong odour and unpleasant taste caused by free chlorine remaining in the water. Furthermore, when chlorine reacts with organic matter in the water, it can form trihalomethane (THM) compounds that are harmful to health. Pesticide residues leaching from agricultural land, heavy metals such as lead and copper entering the water from old pipework, and high levels of limescale (calcium carbonate) can accumulate in the body over time, putting a strain on kidney function. For this reason, it is not recommended that individuals with a sensitive immune system, and in particular babies, consume tap water directly.

A Comparison of Different Types of Water

As consumers try to choose the most suitable water source for their homes, they may find themselves confused by the various alternatives available on the market. Tap water, natural spring water and purified water are terms that are often confused with one another.

What is the difference between tap water and purified water?

Although many people mix purified water with distilled water, the two are completely different. Distilled water is water that has been boiled and evaporated in a laboratory setting, and is 100 per cent free of all natural minerals such as calcium, magnesium and sodium. As it contains no nutritional value, it is also known as ‘dead water’. When consumed, it can disrupt the body’s intracellular osmotic balance. For this reason, distilled water is not intended for human consumption; it is used in hospitals, industrial machinery, batteries and irons to prevent limescale build-up. Tap water, on the other hand, is a ‘living’ form of water that contains minerals from nature as well as added disinfectants (chlorine).

The Differences Between Natural Spring Water and Tap Water

Natural spring water is water that rises naturally to the surface from underground protected areas and retains its natural minerals without human intervention. Whilst tap water is made drinkable through chemical treatments (chlorination), spring water is not disinfected and retains its natural properties. However, natural spring waters sold in plastic bottles or jugs have a very high carbon footprint due to plastic waste production and logistics processes. Furthermore, bottled water represents a significant cost item for household budgets.

Comparison Table of Water Types

What is the price difference between construction site water and standard (domestic) water?

💡 Did you know? (Construction Site Water Warning) If you are moving into a newly built property and the block has not yet been granted an occupancy permit (building use authorisation certificate), you will be obliged to use mains water at the ‘construction site water’ (commercial subscriber) tariff. Local authorities classify buildings without an occupancy permit as being under construction and charge a much higher price per cubic metre of water than under the standard residential tariff. Checking your building’s occupancy status before moving in will protect your budget from unnecessary billing costs.

Ways to Make Tap Water Safe and Drinkable at Home

The way to avoid the plumbing risks and harmful chemicals posed by tap water is to treat the water not at the source, but the moment it flows from the tap. There is a significant difference in safety between traditional methods and modern technologies.

Is Boiling and Leaving the Water to Stand Enough?

The method of boiling and leaving water to stand, which housewives often resort to, unfortunately does not provide complete protection. Boiling water merely kills living microorganisms such as bacteria and viruses. At the same time, leaving the water to stand in an open container helps the chlorine gas to evaporate, thereby improving the water’s odour. However, these processes cannot remove heavy metals, pesticide residues, asbestos or high levels of limescale from the water. On the contrary, as the water boils, some of it evaporates, meaning that the concentration of heavy metals and limescale in the remaining water becomes much higher.

Water Purification Systems and Reverse Osmosis Technology

The most reliable way to ensure you have access to alkaline, healthy water that you can safely drink at home is to use state-of-the-art filtration systems. In particular, reverse osmosis technology, which purifies tap water at a molecular level, forces the water through membrane filters with pores measuring one millionth of a millimetre under high pressure. As a result, 99 per cent of the lead, mercury, limescale, chlorine and all other chemicals present in the water are removed and discharged into the waste water system. Thanks to high-standard water purification systems developed by leading brands in the sector, coconut shell and natural minerals are added to the purified water in the final stage, raising its pH level to an alkaline level that is optimal for human health.

Under-sink water filtration systems take up no space in your kitchen and add a modern touch to your worktop with their stylish taps. No matter how dirty or rusty the mains water is as it reaches your home through ageing pipes, these units completely eliminate all risks caused by external factors, as they filter the water just before it fills your glass.

The Benefits of Using a Water-Filtering Dispenser

For those who wish to enjoy healthy water not only on the kitchen worktop but also in different areas of the home or in an office environment, water filtration systems offer the perfect solution. Water dispensers that connect directly to the mains supply and purify the water using reverse osmosis technology within the unit itself put an end to the hassle of ordering, transporting and storing plastic water bottles. These units first purify tap water at a microscopic level, then, via their built-in boilers, provide you with instantly ice-cold water or boiling water suitable for making tea or coffee.

Ensuring that staff, particularly those working in busy offices, have constant access to clean water not only boosts work productivity but also significantly reduces company costs. Issues such as running out of bottled water, hygiene concerns regarding plastic containers brought in from outside, or the need to use a separate heater for hot water are completely eliminated thanks to modern water dispenser models. When compared in terms of household economy, filtered water dispensers pay for themselves within just a few months by saving on bottled water costs, whilst providing your family and staff with an uninterrupted supply of fresh, healthy water for many years to come.

Frequently Asked Questions (FAQs) About Tap Water

What does ‘tap water’ mean?

Tap water refers to the entire process that raw water, taken directly from nature, undergoes before reaching our homes. Water collected from reservoirs or groundwater sources by municipal water and sewerage authorities is treated at water treatment works to remove harmful microorganisms and is chlorinated before being delivered to our taps via a network of closed pipes.

Is tap water safe to drink?

In Turkey, mains water is treated in accordance with the Ministry of Health’s criteria and supplied to the mains network in a quality suitable for drinking. However, whether the water is safe at the point where it flows from the tap depends on the cleanliness of the building’s water tank and the age of the pipes. If you are unsure, using a domestic water purification system is the healthiest solution.

What is the difference between tap water and purified water?

Tap water contains natural minerals such as calcium and magnesium, which the body needs, as well as a disinfectant (chlorine). Distilled water, on the other hand, is tasteless and ‘dead’ water that has been stripped of all minerals through distillation in a laboratory setting. As it has no nutritional value, drinking distilled water is not beneficial to health; it is used primarily in industry and in irons.

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