Water’s Journey from Cloud to Groundwater

A vital resource worth protecting       

Most are familiar with the water cycle- the process through which water in surface collections like lakes and oceans evaporates and rises to become clouds, which can travel long distances before raining down on another part of the planet. The water cycle ensures that water is transported inland and supplies fresh water essential to most life. Huge amounts of water are shed during each thunderstorm. On average, a storm that rains an inch of water pours over 25,000 gallons per acre of land. Some of this water immediately flows on the surface towards streams, rivers, or other bodies of water. On the other hand, a good deal of rain also turns into groundwater. This is when water seeps down through the soil until it reaches porous subsurface rocks and collects at a depth known as the water table. The water table in and around Sylva NC averages around 30-40 ft below the surface, however this can vary considerably depending on location. Large collections of water in porous rock, known as aquifers, are a major source for drinking water in the area and provide water for up to 40% of the global population. Most of the available freshwater on the planet is tucked away in the cracks and crevices of the planet’s crust- more than 95% of the freshwater not frozen on Earth is groundwater. This incredibly important resource less than 4 stories below our feet is filtered by rocks and soil as it percolates down to the water table. We must remain vigilant to protect it, however, as groundwater is shockingly easy to pollute by both natural and human means.

 

Water’s journey through the soil is both good and bad       

Humans unfortunately play a large role in groundwater pollution. Oil and gasoline from roads and driveways flow into rivers and seep into groundwater. Aging septic systems seep sewage into the soil (say that 3 times fast), leading to deadly bacteria buildups. Batteries can leak acids if disposed of improperly. In general, anything that seeps into the ground can get into the groundwater. Some pesticides take a long time to break down, and can be found in the soil and groundwater years after an application. Once present in the water table pesticides can be exposed to other organisms outside of the intended treatment zone. Pesticides also collect in runoff, which by travelling through an area can combine to form a deadly cocktail upon entering a nearby stream, river, or lake. This can easily affect aquatic animals which tend to be extra susceptible to these chemicals.

 

Time for a test 

Many of the watersheds in western North Carolina consist of protected forest environments, which leads to largely pristine water stores. This does not mean the water is pure- groundwater naturally takes on different properties depending on the subsurface rocks present. Some aquifers in the area are  known to contain elevated amounts of naturally occurring iron, for example. Many of these natural contaminants are fine for your health, however to get an idea of what is in your drinking water I recommend getting your water tested regularly if you draw water from a private well. Wells access water directly from the water table, so water that seeps into the ground around your well is a large part of what you are drinking. Keep in mind that as the water percolates through the soil it could also be picking up contaminants. As recent events with industrial pollutants like coal ash have shown, homeowners cannot count on local governments or businesses alone to test the drinking water in their area.

Visit http://epi.publichealth.nc.gov/oee/wellwater/howtotest.html to learn more about how to test your well water.

This article was originally published in The Sylva Herald.

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