Potable Water Quality, tell us your opinion!

Potable Water Quality, tell us your opinion!

Know about water quality in Sabade and tell us your opinion!

Sabadell Water Quality


The quality of drinking water is regulated in all EU countries by the same Community legislation, Directive 98/83/Ec. This directive is trasposed in Spain as RD 140/2003. These regulations follow the recommendations of the World Health Organization (WHO) and the latest technical and scientific knowledge.



Water is a chemical compound made up of hydrogen and oxygen atoms (H2O), but also contains dissolved and suspended organic and mineral substances. Its composition depends on its origin, the land and the substances it incorporates.


For an efficient management of drinking water, it is necessary to know the degree of quality and quantity of the water supplied to the population at each point of the supply system. Thus, quality monitoring is carried out involving the evaluation of multiple parameters and periodically.


The results of the main parameters most frequently analyzed in the waters for human consumption of Sabadell (per district) are specified below.






We also appreciate your opinion about the service and quality of the water in Sabadell, so, we encourage you to comment and respond our survey


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Info Parameters

 The regulations that specify the limits of the different parameters of drinking water are Royal Decree 140/2003 of February 7, which establishes the health criteria for the quality of water for human consumption and in the Autonomous Community of Catalonia, for the Health Monitoring and Control Plan of Water for Human Consumption in Catalonia.


Below are some of the most frequently analyzed parameters in potable water control.



Drinking water should not have any appreciable colour.


When colour is display in drinking water, usually in the range of brown, red or yellow, can be caused mainly by:


  • The presence of organic substances present in the land
  • The precipitation of iron or manganese salts.
  • The presence of air microbubbles in its interior. This bleaching of water disappears naturally by letting the water rest.

According to the World Health Organization (WHO) most people can perceive color levels that are larger than 15 true colour units (UCV) in a glass of water. Spanish legislation (RD 140/2003 which establishes the health criteria for the quality of human consumption water) the limit is set at 15 mg / l Pt / Co.


RD 140/2003 - < 15 mg/l Pt/Co  



Drinking water has in its composition, salts and dissolved substances that give it a particular taste and smell.


 The main substances that define taste are the mineral salts of their composition. Therefore, chlorides, sulfates, bicarbonates, sodium, calcium or magnesium are natural compounds responsible for the taste of water.


 Other substances such as residual chlorine also affect the taste and smell of water, as well as substances of anthropogenic origin that, in very small concentrations, can give different flavors.


 The detection of a certain taste and smell of water does not mean that it is not potable. The most essential is the fulfillment of the criteria established in Parts A and B of Annex I of the Royal Decree 140/2003, which establishes the health criteria for the quality of drinking water and the fact that that no substance, microorganism or parasite that exists in a concentration that could represent a risk to human health.


The taste and smell parameters are limited by the RD 140/2003 as indicator parameters, set as a dilution index.


The dilution index represents the number of times that the water must be diluted at a given temperature (25ºC) so that it hasn’t significant taste or smell. This is limited to 3. It is a value that is determined from the point of view of the acceptance of water by consumers, rather than a health value that determines if the water is potable.


RD 140/2003 - < 3 a 25ºC Dilution Index




Drinking water has in its composition, salts and dissolved substances that give it a particular taste and smell. 

The turbidity in drinking water is caused by the presence of particles of matter. This can be caused by inadequate treatment of drinking water, by the precipitation of iron salts or manganese (in high concentrations) or by the suspension of particles deposited in the distribution network. 


From the WHO (World Health Organization) it is established that turbidity values ​​below 5 UNT are usually acceptable by consumers. 


However, the particles can protect the microorganisms from the effects of the disinfection, for this reason, whenever water is subjected to a disinfection treatment, its turbidity must be low, so that the treatment is effective. Royal Decree 140/2003 establishes the limit of turbidity at the exit of the treatment process and/or the water tank of 1 UNT and 5 UNT in the distribution network. 


At the same time, turbidity is also an important operational parameter for the control of treatment processes, and may indicate the existence of problems, especially in the coagulation and sedimentation during the filtration process.


RD 140/2003 - < 1 UNF Exit of Treatment / Water Tank

RD 140/2003 - < 5 UNF Water Network




Ammonium present in the environment comes from metabolic, agricultural and industrial processes, as well as the disinfection with chloramine. Ammonium is an indicator of possible contamination of water with bacteria, wastewater or animal waste.


Exposure to ammonium from environmental sources is insignificant compared with that derived from its endogenous synthesis. Only toxicological effects are observed in exposures of more than 200 mg / kg body weight.


The presence of ammonium in drinking water has no immediate impact on health, so that no reference value based on effects on health is proposed. However, ammonium may reduce the efficiency of disinfection, cause the formation of nitrite in distribution systems, hinder the elimination of manganese during filtration and produce organoleptic problems. Thus, the RD 140/2003 establishes the limit of Ammonium in 0.5 mg / l.


RD 140/2003 - < 0,5 mg/l 




Chlorine is the agent most used for the disinfection of drinking water. The main reasons are:


  • Its highly oxidizing nature that allows the destruction of pathogens (especially bacteria) and other compounds that cause bad taste
  • The innocuity of the product at the concentrations used
  • The ease of controlling and checking the levels and process


In order to guarantee the disinfection process, it is essential to keep small residual chlorine concentrations in the distribution network. In any case, it should be taken into account that its absence does not imply the presence of microbiological contamination, being identified as an indicator parameter in RD 140/2003.


Free Residual chlorine in water is found as a combination of hypochlorite and hypochlorous acid, depending on the pH. The combined residual chlorine is the result of the combination of chlorine and ammonium. The sum of the two is known as total residual chlorine.


According to Spanish legislation, the level of free residual chlorine is set at a maximum of 1mg / l and and the level of combined residual chlorine at 2mg / l. Regarding the area of ​​Catalonia, the Health Monitoring and Control Plan of Water for Human Consumption establish also a minimum level of free residual chlorine of 0.2mg / l and it is recommended that it to be maintained between 0.2-0 , 6mg / l.


RD 140/2003 and Health Monitoring and Control Plan of Water for Human Consumption in Catalonia - < 0,2 mg/l – Free Residual Chlorine < 1 mg/l 

RD 140/2003  - Combined Residual Chlorine < 2 mg/l 




The conductivity is the measurement of the capacity of an aqueous solution to conduct an electric current. This property is related to the ionic content of water and total solids dissolved.  

All substances allow a certain degree of conductivity, pure water, due to the low number of ions, is not a good conductor of electricity, however, salt water offers a much higher conductivity. Regarding to the water of human consumption, its value in RD 140/2003 is limited in 2.500μS / cm.  

It is used to determine the amount of total solids dissolved in water, detect variations or changes in the water or in order to determine the size of the sample for its analysis.   High value may mean the detection of water taste or problems in equipment and pipes.


RD 140/2003 - < 2500 µS/cm at 20 ºC




Although the pH does not usually affect consumers directly, this is one of the most important operating parameters of water quality. In all phases, it is necessary to have a special control of the pH in order to carry out the correct treatment and disinfection process. 


For an effective chlorine disinfection process, it is preferable that the pH is below 8; however water with lower pH will probably be more corrosive for the facilities. 


The pH value varies depending on the composition of the water and the nature of the materials used for its distribution, however, it is usually found between 6.5 and 8 u.pH. The Spanish legislation through RD 140/2003 establishes the limits of pH between 6.5 and 9.5 u.pH.


RD 140/2003 - 6,5 < pH < 9,5 UpH




The absence of microbial pathogens is one of the main parameters analyzed to determine the potability of water.


The detection of groups of microorganisms such as coliform bacteria, escherichia coli, enterococci, aerobic bacteria or Clostridium perfrigens is an indicator of fecal water contamination.


The effects of fecal water contamination on health vary depending on the microbiological agent; If there is no pathogen, there will be no illness but it can cause gastrointestinal discomfort, vomiting, diarrhea, etc., mainly affecting children, the elderly and immunodepressed.


RD 140/2003 considers that the elements previously aforementioned must not be present in the water of human consumption, being 0 UFC in 100 ml the limits established.


For this reason, as a preventative measure, it is necessary to keep the water properly disinfected and carry out a control of the process in order to minimize the risk of microbiological contamination.



RD 140/2003 – Coliform Bacteria < 0 u.f.c. /100ml

RD 140/2003 - Escherichia coli < 0 u.f.c. /100ml



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Service Quality Survey

Companyia d’aigües de Sabadell conducts surveys with the objective of knowing the degree of satisfaction of the users about different aspects related to the Company.  


Apart from data regarding the quality of the service, also questions about the quality of the potable water supplied are asked. The results of the questions related to the quality of drinking water made by telephone between August 24 and September 2, 2016 are shown below:











We also appreciate your opinion on the service and water quality of Sabadell, so we encourage you to comment and respond to our online survey!



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Sabadell Service Quality

CASSA offers maximum efficiency in the management of supply cuts, minimizing the impact on subscribers, both in affected hours and in the number of users.


There are two types of supply disruption:

- Program interruptions:

Supply cuts can be given to allow the execution of planned work in the network such as the maintenance of the elements or their extension.

In these cases, the affected consumers are informed through announcing posters located in visible places.

CASSA also offers the free warning service to subscribers subscribed through sms messages which informs about the schedule of the interruption and the time for the restitution of the service.


- Unforeseen interruptions:

The rest of the interruptions due to failures in the infrastructures are also informed through message sms to subscribed subscribers. They also inform about the expected duration of the repair and restitution of the service.

 Avis de tall de subministrament


If you want to receive free mobile notices about the service interruptions that affect your address, fill out with your information in this form  





 93 748 64 14 - clientes@cassa.es - @AiguesSabadell






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