My recent articles have been about our sea water and pond water – but what about our drinking water?
The Lowcountry has obtained most of our drinking, or potable, drinking water from the Floridan Aquifer. This is one of the most productive aquifers in the world. This aquifer system underlies an area of about 100,000 square miles including the part of Georgia, South Carolina, and all of Florida.
In 2018, total groundwater withdrawal in Beaufort County was reported to be approximately 7.4 BGY (billion gallons a year) or about 20 MGD (million gallons a day). As the seas rise, increasing the pressure of the salt water, our entire source of fresh water is increasingly at risk.
These days much of our drinking water now comes from Savannah River after treatment, in part due to the number of wells that are no longer usable for drinking.
What constitutes “too much” salt in our water? Let’s start with how much salt is normal for the human body.
Normal saline contains 9,000 milligrams (mg/L) of salt per liter of water. We get salt from many of our foods, so we probably don’t want to drink water with a salt ratio as high as 9,000 mg/L.
Most people can taste salt in the water around 250 to 400 mg/L. Seawater contains 35,000 mg/L of salts (mostly, sodium chloride). That high salt content is deadly.
According to Brooke Czwartacki, hydrologist with the South Carolina Department of Natural Resources, many of the wells in our area had to be closed due to too much salt getting into the water supply.
While the amount of rainfall and other factors play a role, in general the more water we use for drinking, irrigation, industry, etc. the greater the chance salt will enter our water.
When asked how we can drink less water, Czwartacki pointed out that we really don’t want to do that. We need to stay hydrated. But there are things we can do to preserve our freshwater resources.
A large part of the fresh water we use is to irrigate our lawns and gardens. One way to cut our use of fresh water is to plant native plants and grasses that have adapted to our warm climate and require less water.
The Clemson Cooperative Extension has some good ideas for low-water-use plants. Visit Clemson.edu/extension and search “plants that tolerate drought.”
The time of day when we water plants is important for water conservation. In summer, early morning (before 6 a.m.) is good. The worst time to water is between 10 a.m. and 2 p.m., when the sun is hottest. Late afternoon through around 6 p.m., is okay. (Do not water at night as this can cause issues for your plants.)
The very beauty of the Lowcountry is what makes people want to move here. But population increase is also its biggest threat. We are not going to stop development or keep people from wanting to enjoy what we enjoy. However there are things we can do to preserve what we have.
John Riolo lives in Moss Creek and is past president of the Nature Club of Moss Creek. firstname.lastname@example.org