There are a number of reasons why your drinking water might taste salty. Some of these reasons are concerning, some of are less so, but they are all worth investigating.
What Minerals Cause Salty Tap Water?
There are few reasons your drinking water might taste salty, but a common ones are:
- chloride (primarily sodium chloride, which is commonly known as salt)
- magnesium
- sulfate
which are common contaminants in drinking water. Each of these are considered to be “secondary contaminants” as they are not of primary concern, which would be the case with minerals like lead or chemicals like arsenic.
Most salty tap water comes from chloride, particularly sodium chloride (the same mineral as table salt), entering the water and imparting a salty taste. Seawater intrusion or salt deposits in your groundwater are common causes.
A high level of TDS, total dissolved solids, can also cause salty tasting water, but that’s only because the dissolved solids contains chemicals like these above.
How Much Salt Is In Drinking Water?
The World Health Organization (WHO) has set a guideline that drinking water should have under 200 milligrams/liter of sodium in it in order to taste as fresh drinking water should. This is what’s know as an “aesthetic” concern as water past this point could still be drinkable.
US water quality standard, set by the Clean Water Act and the US Code of Federal Regulations Title 40 section 121 is more concerned with water contaminants than salt levels, and neither has set a legal limit for sodium in drinking water. Even so, most states and the EPA recommends salt levels of under 20 mg/L in drinking water for people with with low sodium needs and under 270 mg/L for everyone else. Chloride is to be kept under 250 mg/L for optimal taste.
Humans can typical start to taste salt in water at concentrations starting at 30 mg/L and can tolerate water up to about 460 mg/L.
For reference, ocean water has, on average, 30,000 mg/L of salt in it.
Water Softeners And Regeneration
If you have hard water, a softener is often used to “soften” the hard, mineral-packed water. Unfortunately, a salty aftertaste can sometimes be a result of this process as salts are a normal component in softeners.
There is a simple reason this occurs: internal seals in the soften mechanism can wear out and leak salty water into the cleaned water which happens in the next stage.
Something similar can also, though rarely, happen with public water. You may also find the water that you consume in the middle of the night might be salty. This happened because there is a process known as “regeneration” where water that has been soften gets minerals added back in and they are sometime not perfectly distributed. Water treatment shouldn’t add more then 30 mg/L of salt to water so it’s a minor issue on the whole.
Salt in the water damages pipes and heat fittings as well. A bad connection in the plumbing apparatus like a clogged injector, drain line, maybe the cause why salt attaches itself to the pipes.
Water Softeners and Salty Water
A common misconception is that a water softener causes your tap water to taste salty. This is not impossible but this is not the norm with a quality, professionally installed softener, for example the Culligan HE Water Softener. Salty water can come from a regeneration cycle issue, but that will usually be a caused by a fixable issue like a plugged drain line which prevents the softener from flushing out excess water.
Contaminants From Your Area
Sometimes salt and salty-tasting minerals can get into the water through the surrounding area. If you live by the ocean, sea, or a bay, water can sometimes enter pipes and make tap water more salty than it should be. Salty tasting minerals, like those above, can similarly enter the water stream, depending on the make-up of the ground deposits in your area and the condition of the pipes. Sodium makes up about 2.6% of the Earth’s crust, so local deposits aren’t uncommon.
In cold weather climates, road salt deposits can dissolve into the surface water and filter into the water supply. However, there are no documented serious human health water problems to this practice and this is rare as it would take a lot of road salt over a sustained period of time.
Sodium is commonly used in a number of applications include the creation of chemicals, de-icing (as mentioned), food processing, and industry so it’s not impossible for it to enter the water through some form of industrial or commercial usage.
A Logical Explanation
There is a natural reason as to why groundwater has an element of sodium. Rainwater falls on the earth. It dissolves sodium sulfate and magnesium sulfate into the groundwater.
Shale waste from chemical or industrial plants near your home/office may also be the usual suspects. The content of the chemicals in the water may require a reverse osmosis filtration system or something comparable to rid the water of high levels of salt and other contaminants.