It depends on the source of the water. If the water is coming from the ground or rain, it might not be clean enough to drink. City water is often clean enough to drink as it is filtered but you have to check with your supply company and see what they recommend. There are other things to consider as well. Let’s dive in.
Source of the water
Your house should have plans that indicate what water source is being used for each faucet. City water has to follow strict rules and is cleaned and checked. In some locations, the owner of the house has to add a sticker above the faucet if the water is undrinkable. This makes sure that there is no confusion with renters or guests. Check the local rules to make sure what is needed.
These can be very strict and fines might have to be paid if the indication is not clearly present. A lot of people remove this sticker in the bathroom as it doesn’t look nice. Once the house is sold, no one thinks about placing this sticker back or informing the new owners that the water is not safe to drink.
Water from your own well (groundwater) is not checked by anyone and you are responsible to make sure that the water is clean. This can be done with filters. A lot of people don’t clean these filters and lose their advantage. Water can contain a lot of elements that are not visible. You can also check your well from time to time to check if everything is looking clean. No dirt should be leaking into it. If you have a septic tank, you should make sure that it doesn’t leak as this can contaminate the water as well.
Some houses mix groundwater and city water in the same water circuit. While this is not allowed, it can get mixed in your installation. This can contaminate the water and make it unsafe to drink.
Your plumbing system: is tap water hard or soft?
Depending on your area, the water can contain a lot of calcium (this is called hard water). Some people install a water softener in their home to remove the calcium from the water as this can create stains on dishes and clothes. You can check with your water company to see if you have hard or soft water. Water can be quite cloudy if you have calcium in it. A water softener can make water undrinkable as well so be careful when you have one.
If you have old pipes, it is possible that steel leaks in them, and this can make the water undrinkable. Pipes can rust and leak this in your water. An old water heater can do the same. Water can get a special smell or color in these cases and shouldn’t be used. People often don’t realize this and just rely on the advice of their water company but that is not enough as your own plumbing system might.
Over the years dirt can collect in your faucet and pipes and this can affect the quality of the water as well. Furthermore, rodents often chew on pipes and they can make the water undrinkable.
If water is standing still in your pipes for a while, it can become undrinkable as well. If you have been on holiday, it can be a great idea to open the faucet for a while. This cleans the drains and fills the p-trap again.
Modern water heaters with a water tank have a program in which they heat up the water to a high temperature from time to time. This removes a lot of dirt particles from it. If you have an older water heater, it is possible that this program is not present and the warm water can be unclean.
Using a small water filter might remove some elements from the water but it can’t catch everything. Some particles are very small or strong and these filters are unable to catch them.
How to be sure that you can drink the water from the tap.
To be really certain that you can drink the water in your bathroom, a lab test is needed every few months. The quality can evolve over time so it is essential that you test it multiple times. This requires that you send a water sample and then they check for different elements. If they detect elements that are not suitable, they will warn you and provide advice on how to remove them from the water. These tests can cost a few hundred dollars. It can take a few days or weeks before you get the results. Make sure that you pick a lab that is certified and has experience with these tests. You can reach out to a plumber to get an idea of what labs they have worked with before. Real estate agents can help you out with this as well.
There are digital meters but these are often not accurate enough. They are also not able to measure everything that should be checked. For these reasons, I am not a big fan of them.
You can get a testing kit and perform the tests yourself. It won’t be as accurate as a lab test but can give a general idea of the quality of the water. These tests are quite easy to perform, from dipping a piece of paper in water to filling a bottle with water. You get the results quite fast. It is still a great idea to get an initial test from a lab as these can measure more elements and are more precise.
Given that it is always possible that something changes between tests, you can never be 100% certain that the water is safe. Bottled water has a higher chance of being safe and is often recommended for younger people.
To conclude, it is difficult to tell if the water in your bathroom is drinkable without doing a test. A lot of things can be wrong with the water and a detailed test can check what is going on. A test can cost a few hundred dollars and has to be repeated from time to time but it is better to be safe than sorry. Not enough attention is being paid to this so it is great that you are doing an effort to check if it is drinkable!