After the first rainfall in over 50 days across parts of the UK, millions of residents in South and Central England may notice a 'musty' or 'earthy' undertone in their tap water over the next few weeks, according to experts. The phenomenon is linked to the heavy downpour that followed a prolonged drought, which has altered the composition of natural water sources.
Why does tap water taste 'musty' after rain?
Dr Bill Simpson, a chartered chemist, explains that the recent wet weather is likely to blame for the unpleasant taste. 'Heavy rainfall can create problems for those responsible for treating water and can even lead to the water from our taps taking on a variety of unpleasant notes,' he told Metro.
The dry, hard ground is less able to absorb water, so more runs off the surface, carrying soil, pollutants, and other materials into rivers and reservoirs. This runoff introduces higher concentrations of phosphate and nitrate, which, when the sun returns, encourage the growth of photosynthetic bacteria and algae. These organisms produce compounds that give water an 'earthy' flavour and smell, which are 'notoriously difficult to remove during water treatment,' says Dr Simpson.
Is the water safe to drink?
Despite the taste, Dr Simpson stresses that the water remains safe. 'We've pretty much eliminated the chance of getting sick from drinking tap water in this country,' he assures. Water treatment plants are required to remove enough contaminants to ensure safety, but they are not required to make the water 'pristine,' so traces of taste and odour compounds may remain.
In some cases, treated water with high levels of these compounds cannot be supplied to consumers and must be blended with cleaner sources, Dr Simpson adds. However, treatment plants also have volume requirements, so a compromise is often necessary.
Chlorine smell and home solutions
Some Brits might also notice a 'chlorine smell' in their water. Dr Simpson explains that the influx of pollutants and microorganisms 'cause a whole world of pain' for treatment plants, and higher chlorine levels may be used to lower microorganism levels. Chlorine is already added during normal treatment to combat harmful microorganisms.
For those bothered by the taste, Dr Simpson recommends treating tap water at home with a water softener system or a standalone purifier with activated carbon filters, which can improve taste and reduce chemicals.
