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El Atabal water treatment plant in Malaga city manages to refine very poor quality water at source and is constantly being modernised. Migue Fernández
What is the tap water quality like across Malaga province? These are the best and worst performing places
Data special

What is the tap water quality like across Malaga province? These are the best and worst performing places

SUR has compared laboratory analyses of drinking water from the 16 most populated municipalities, with many differences ranging from almost mineral water standard to very poor, although all are fit for human consumption

Chus Heredia

Malaga

Tuesday, 28 May 2024, 09:40

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Obtaining water fit for human consumption involves a veritable collection of procedures from the source until it comes out of the tap. Poor quality, untreated water can be transformed into almost mineral water standards after dozens of complex steps involving physics, chemistry and transportation. Everyone does what they can within their means because it is not the same to have a powerful desalination plant, as in Malaga city, as it is to have to make do with traditional processes, as in smaller towns and villages.

As if that were not enough, the ongoing drought situation complicates this small daily miracle that flows from our taps, as water from the wells in the province often has very high levels of salt and lime, even some chemical residues.

SUR has analysed the data on the water that comes out of the taps of the 16 most populated municipalities in the province based on analyses done to 23 May by Sinac, the national drinking water system (Ministry of Health). In addition, in the case of multiple supply networks, the most central or those with the greatest population coverage were taken. In general, all are made up of quite hard water (lime deposits) and with high levels of conductivity (salinity), but all are clearly within the parameters set by public health standards. The analyses are the latest available for Estepona, Marbella, Mijas, Fuengirola, Benalmádena, Torremolinos, Malaga, Rincón de la Victoria, Vélez, Nerja, Antequera, Ronda, Cártama, Alhaurín el Grande and Alhaurín de la Torre. The municipalities not explicitly mentioned in the text present intermediate and fairly homogeneous values in general.

The importance of the desalination plant

In general terms, it can be concluded that the water in Malaga city is the best, with just 88 hardness and a moderate 579 in conductivity. It is followed by Vélez-Málaga, although its 128 hardness in the last published analysis will probably have increased because the analysis is from the time when the Axarquía was receiving 270 litres per second from Malaga city. This fact, for example, was confirmed in Rincón, which has now reached more normal and higher levels of hardness after these transfers stopped. Another town with notable water quality is that of Antequera, which is semi-soft (160) and by far the least saline (265) in the province. In view of the data, it is probably among the best, if not the best, water extracted at source (from El Torcal natural park).

At the other extreme is the water coming out of the taps in Cártama, with a high salinity (2,220) and hardness (505) and Mijas (852 and 679). In earlier analyses Fuengirola was of very low quality, reaching 1,072 in salinity, probably due to the mixing of water from wells. The situation has been reversed in the last analysis, with a salt score of 550.

In the case of Cártama, and this is something its mayor Jorge Gallardo regularly complains about, the municipality serves a population of 30,000 with no recent regional investment apart from the fact that a transfer of 100 litres per second from the Aljaima wells, managed by Emasa (Malaga city's water company), is now going to be guaranteed. The quality of the aquifers in this area and those of Alhaurín El Grande are declining due to the drought, and this would explain the data. A solution for this case and for others is the connection to the Malaga network, as is going to happen for Alhaurín de la Torre, and the future conversion of the Pilones water treatment plant into a desalination plant, similar to El Atabal, which would guarantee good water for taps from poor quality at source.

A close-up view of one of the water-control processes at El Atabal.
A close-up view of one of the water-control processes at El Atabal. Migue Fernández

The case of Mijas, with data taken from its most important water works in Las Lagunas, may be due to the mixing of the water served at high levels at source by the suppliers Acosol with other water taken from wells and even, according to technical sources consulted by SUR, due to some saltwater incursions.

The spectacular figures for Malaga attest to the soundness of El Atabal to deliver good drinking water, which has also recently had its capacity increased and is going to add ozone treatment capacity. It has been a surefire way of coping with the drought and is now prepared to treat very poor quality, untreated water such as that from Bajo Guadalhorce. This has broken the traditional myth that one could not drink the tap water in Malaga because of its hardness, a belief that is still inexplicably held by large sections of the population.

Water hardness, the problems

Hardness or limescale is a problem in large quantities and in combination with other phenomena such as high temperature and high pH levels in the tap water. It produces salt deposits in pipes, leaving them heavily encrusted, reminding us of those classic advertisements for limescale removers to clean household appliances. In theory, the more limescale the worse it is for cooking food, the drier the skin and the more laundry products to be used. High limescale can also be detrimental to people with a tendency to form kidney stones.

El Atabal has broken the traditional myth that in Malaga you couldn't drink tap water because of its hardness

High levels of lime have a negative effect on how the water tastes. We can regard water below 150 as soft, semi-soft up to 200, hard up to 400 and from there upwards very hard up to 550.

Total hardness or lime, popularly speaking, determines the amount of calcium and magnesium ions dissolved in water, usually expressed as mg/l calcium carbonate.

Conductivity or salt

There is no quality parameter for conductivity or salt, but sources consulted warn that from 800 or 1,000 it starts to be noticeable in the taste. It is a parameter measured in µS/cm and is limited to 2,500. "Low conductivity values indicate good water quality, as it will have low levels of dissolved salts such as chlorides, sulphates, sodium, calcium, potassium and magnesium", states Emasa's website (Malaga's municipal water company), which posts the results of its analyses on a daily basis.

Another factor that affects the taste of water is the best possible sanitiser, chlorine, which is required by health regulations. It has to be between 0.2 and 1, so that the ideal, according to other sources, are intermediate values. In this area the limits are set by Rincón de la Victoria and Fuengirola, with 0.2 mg/l of free chlorine, and Cártama, Alhaurín de la Torre and Torremolinos, with 0.8.

Turbidity, odour and taste

If we look at how cloudy the water is that comes out of the tap, the best indicators are in Estepona, Rincón, Cártama, Torremolinos, Vélez, Ronda, Nerja and Marbella, with 0. At the other end of the scale, Fuengirola (1).

Other indicators reported in the analyses consulted concern odour and taste. In this respect, not all water companies use the same settings. For some the base is 1 and for others it is 0, but we can say that none of the water in the province presents problems according to either of these parameters.

All the above data, other than those relating to lime and salt, are as of analyses done up to 17th May.

The water that comes from the reservoirs also varies in quality. It is well known that the Guadalhorce can become a little salty due to the Meliones spring that flows into the main reservoir. In the past, the water had to be mixed until the levels were acceptable, but with El Atabal plant now in place, those problems are over.

With regard to lime, the water of La Viñuela is around 220 and that of La Concepción 270 respectively. In the case of Acosol (water supplier for Western Costa del Sol), it also has a great ally to refine water quality in the guise of the Marbella desalination plant that is now being expanded in two phases.

Municipalities such as Marbella and Alhaurín El Grande show semi-soft water values. The rest of the province shows high levels, with Ronda as the third municipality with the highest levels of limescale in tap water.

In terms of pH, the most alkaline waters are Antequera, Rincón, Mijas and Fuengirola (above 8). The most neutral - there is no acidic water in the province - are Cártama, Coín, Marbella and Ronda (around 7.5).

Differences within the same municipality

In the study it is the main networks that have been examined, but even within one municipality there are abysmal differences. For example, in Alhaurín el Grande the main network gives an excellent level of lime, but this rises to 340 in the Ardalejos network.

In Cártama, for example, there are some much better indicators (659 for conductivity and 357 for hardness in Gibralgalia). A special case is Mijas, a very diverse municipality in terms of its supply network, with more than 30 measuring points. In El Pueblo, 274 of lime and 469 of salt are present, whereas in Calahonda it is 174 and 517 respectively.

Andalucía: Granada wins on low salt and Almería, with its desalination plant, on less lime

Desalination treatments achieve such good results that it is normally necessary to re-mineralise the water after treatment because our bodies reject water that is almost distilled. The analysis of data from Sinac, the Ministry of Health's National Drinking Water System, shows Almera as the Andalucían provincial capital with the best rating for hardness (45). It is followed by Huelva (63) and Malaga (88), also with a desalination plant in this case.

In the case of water quality at source, the myth of the springs in Granada is true. The provincial capital, home to the Alhambra, provides tap water with a hardness of just 88 and very low salt (160), the lowest by far in Andalucía. In Cordoba (269) the salt levels are very spot on. On the other hand, the waters with the highest levels of salt in the region are Jaén (599), Malaga (579) and Cadiz (456).

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