This is a bit like hauling coal to Newcastle, but I have talked to a few local folk recently who did not know from where their water comes.
The agricultural community in and around Pembroke is acutely aware of the importance of water and rainfall. The business and construction industry in the south end of the county is painfully aware of what happens to a community’s economy when government turns the water tap off.
In spite of this, many people seem to be able to go through their day-to-day lives oblivious to the sources of their water and the basics of how that water reaches them. It would not be such a concern, but water is becoming an ever-increasing issue locally, nationally and globally. On the personal level, we can live without food for about three months, without water for three days and without air for three minutes.
So, right to the question that prompted this week’s column: “We live on a golf course and are worried that the chemicals and fertilizers they use will get into our drinking water.”
First, you are not drinking water that comes from the golf course. If you are in a subdivision you are either on a private well serving your subdivision or you are on a public water system.
In Bryan County and most of southeast Georgia, our drinking water is groundwater from the Floridan Aquifer. The Floridan Aquifer is a huge sea of fresh water that underlies all of Florida and up the East Coast past Charleston, extending on a line from north of Charleston to just southeast of Macon and down into southern Alabama past Mobile and into Louisiana. Miami, Savannah, Charleston, Orlando, Tampa, Panama City, Mobile and all the smaller towns in between all have their straws sucking water from the same underground pool.
An easy way to think of this is to make a seven-layer yellow cake with chocolate icing. Next set one corner of the cake on an upside-down dessert plate so the cake and its layers have a slant to them. Now push down the top layers on the high corner until they are level with the low corner.
At the most elevated end, the fourth layer down is almost at the surface. This represents Port Royal Sound and Hilton Head Island where the Floridan is exposed in the bottom of Port Royal Sound. Farther down at the Ogeechee and Richmond Hill, the fifth layer is two hundred feet underground. Down at the Florida state line and St. Marys, the Floridan may be five hundred feet down.
Each of the cake layers is a water-bearing layer, and some have better quality water than others. The Floridan water is drinking water quality as it comes out of the ground. The only reason we chlorinate it is to get it through our dirty pipes and secondarily to knock out the sulfur smell.
Yes, all Floridan water has a sulfur smell to it. Expose the water to air and the hydrogen sulfide evolves off almost instantly.
The chocolate icing represents the layers of rock that confine the limestone water bearing layers. These layers protect the water in a layer from contamination from above and below. To get to the Floridan layer, well drillers bore through the top layers of lesser-quality water strata and confining layers until they hit the Floridan. They drill into the Floridan-bearing layer to tap its depth and maximize the yield of the well.
They put a metal or plastic sleeve down the well to the top of the confining layer over the Floridan aquifer to keep contamination from the other layers above it out. The sleeve, called a casing, is also grouted, usually with bentonite clay, to form a seal to keep stuff from the surface from migrating down the outside of the casing.
I do not know of a single case of any contaminants from the surface ever migrating down a cased and grouted bore more than a couple feet, and that was due to rodent tunnels making a path.
Let me put it this way, when we lime our lawns, the lime changes the pH of the soil – sweetens it – at a rate of about 1 inch per year. The pesticides we have on the market today are designed to degrade in a short time, usually between two to six weeks.
Some are rapidly destroyed by light. Most are broken down by soil microorganisms and used by them for food. Nitrogen is scarfed up by nearly every life form in the soil and battled over so competitively that we don’t even test for it is soil samples sent to the Athens soil lab.
Folk worrying about pesticides applied to the landscape are worrying about the wrong things. The place to worry about pesticides is in the average homeowner’s garage.
The biggest threat from pesticides is faced by firefighters and other first responders when those improperly stored things like paint, pesticides, motor oil, cleaning supplies and fertilizers become a witches brew in a house fire or in a flood.
Want to help the environment? Clean up your garage and store your own chemistry properly.
Gardner is the extension agent for Bryan County. He can be reached at email@example.com.