Does your water taste salty?

In McHenry County, virtually all of the water people use in our day to day lives comes from the ground - groundwater.

An important thing to remember about groundwater is that once pollutants make their way into the water that is underground, it is very difficult and expensive to remove.

A "contaminant" of growing concern in local groundwater supplies is chloride - an element that is being introduced to the groundwater through septic systems that are connected to homes with water softeners and also road salt.

The salt that is commonly used in water softeners to remove hardness from household water is Sodium Chloride (NaCl). The water "softening" process results in the release of high levels of sodium and chloride ions into the septic system where they quickly pass into the drain field and down into the groundwater.

The standard for chloride in drinking water is 250 milligrams per liter (mg/L). This is the level at which the water will taste salty to most people. Less chloride than that and people tend not to notice it.

According to the US Environmental Protection Agency (USEPA), standards for chloride in drinking water are merely guidelines since chloride does not pose a health risk - at least not at levels low enough that we cannot taste it.

We've all heard advice to limit salt intake to help stay healthy, right? It's linked to high blood pressure and thereby an increased risk of heart disease. For humans, the primary source of salt (sodium chloride: NaCl) is the diet.

But, there are members of our community who "taste" chloride at a level of less than 100 mg/L, and whose well-being is profoundly affected in even these small amounts. The level of sodium found in McHenry County groundwater (in the Boone Creek watershed) is already 80 mg/L AND RISING!

A study documenting the dramatic increases in chloride levels in even rural areas of the northeastern US provides a lot of good information about the ecological impact of increasing salinity. The impacts include:

- altered natural community composition (many plants and animals cannot tolerate the higher chloride levels, so are replaced by those that can)

- changes in plant and animal reproduction and mortality (some plants and animals stop reproducing, and others die)

- changes in the structure of microbial communities.

This last one may seem trivial, but those microbes are critical to the soil food web that so much of life depends upon. Consider that oak growing in your yard - if the water table becomes salty, the beneficial fungi and microbes that the trees roots depend upon to feed the tree can die, and then the tree won't be far behind.