The white is due to air having been dissolved into the water and formed tiny bubbles, which are actually microbubbles. It mainly comes from pressure oscillation in the pipes or reservoirs making the water whitish for some time.

This appearance will go away and will not affect the quality of the water. If you let the water rest for some time in a transparent glass or jar, you will see it become easily clear again.

Chlorine is a used disinfectant for water treatment, which secures its microbiological quality throughout its course, from the Treatment Plants, passing by the Distribution Network, to the Customer taps.

Low doses of chlorine are added to the water as to ensure residual chlorine values, which are suitable for maintaining its microbiological quality as established in the Portuguese legislation (Decree-Law No. 306/2007 from August 27th, 0.2 to 0.6 mg/L of free residual chlorine).

You may occasionally smell or taste chlorine, in which case you should let the water rest for a few minutes until its smell and taste go away.

After too much time with water having been cut off (i.e. vacation) there may be noise in the piping and water may spurt out when you open the tap, which is caused by air in the pipes. You should let water run for a few minutes so that the water which had stopped in the pipes can be replaced. Remember that the quality of your water also depends on the condition of your main drains.

The Portuguese legislation on the quality of water for human consumption is Decree-Law No. 69/2023 from August 21th.

Hard water for human consumption is essentially caused by the presence of calcium and magnesium salts, hence it is considered hard when there are significant values of these salts and soft when there are small quantities.

EPAL's water hardness levels in the city of Lisbon are between 40 mg/L and 170 mg/L of calcium carbonate (CaCO3) where the average is 80 mg/L. Water hardness in this range is not a health hazard for consumers.

Please Note | The value of 80 mg/L of calcium carbonate is equivalent to 8 French degrees (ºfH), 4.4 German degrees (ºdH) and 0.8 mmol/L.

The pH (potential of hydrogen) translates the water's acidity or alkalinity. The pH scale comprises values between 0 and 14 where a pH value of 7.0 is the indication of a neutral solution.

EPAL's water pH is in compliance with the established values in the effective legislation (≥6.5 and ≤9 pH units).

The age and conditions of preservation of the plumbing and installed boosters (if any) may change the water characteristics, particularly its taste, colour, and smell. The temperature of the water may also influence its taste. Fresh water is more pleasant to taste.

The results of lab analyses carried out by EPAL in compliance with the effective legislation are published every three months on the written press and available on Communication of Water Quality data »

This colour is caused by the presence of iron in the water, which may be due to its existence in the water origins, along with phenomena corroding steel or cast iron pipelines installed in the distribution system and main drains.

Iron concentrated in the water distributed by EPAL is in compliance with the legally required values (0.2 mg/L) and are not a public health hazard.

What do I do if I have lead pipes? 
It is recommended that you replace/renew them as to reduce the amount of lead dissolved in the water.

Filter and purifier demonstrations intend to make you believe that your water is of bad quality. They resort to electrolysis or reverse osmosis in order to eliminate mineral salts and other natural compounds in the water and turn mineral and balanced water into an equivalent of distillate water.

You may obtain information on this matter provided by "Entidade Reguladora dos Serviços de Águas e Resíduos" (ERSAR). Click here »