At least twenty municipalities have been identified as having tap water whose quality is far from ideal, although the levels of various impurities do exceed the safety margins.
The main problems with these water supplies is excessive lime, insufficient chlorine and the presence of nitrates and pesticides from fertilisers.
Chlorination is the only guarantee that the water reaches the taps of homes without presenting a danger to the public, since it prevents the proliferation of algae and fungi in pipes and storage tanks. Ten municipalities fall short in this area.
Water hardness has no adverse health effects, but can damage appliances and clog pipes due to high concentration of lime. Thirteen villages suffer from this problem.
The use of fertilizers and other products for agriculture and livestock has a negative impact when it leaks to underground reservoirs of water. Around 22% of the population of Málaga drinks water that comes solely from under the ground, while 75% drink water which involves some subsurface fluid. Six municipalities have been found to have suffered a deterioration in the levels of nitrates.
High concentrations of sulphates in water can cause diarrhea and even dehydration. The water pipes may also become damaged. The sulphates levels are worsening in two municipalities.
Málaga province spends 34% more on water than the national average and 26% more than anywhere else in Andalucia. It also consumes 275 litre per capita per day, although 30% is apparently lost through leaks.