Written by Carol Frank, firstname.lastname@example.org Thursday, 11 July 2013 00:00
Recently, the directors of the Water Authority of Great Neck North met to take a tour of the water supply and treatment facility that is located in a bucolic setting off Community Drive.
A new well has successfully been added to the two other wells on the five-acre parcel that was acquired by eminent domain 15 years ago, in order to insure sufficient water for the demands of a growing community. The need for the acquisition was heightened by the closing of wells on the peninsula due to saltwater intrusion.
When the facility first opened in 2000, it housed two wells and an activated carbon filter was installed for cleaning the water of a variety of contaminants.
Since that time another well was successfully drilled and in order to protect the water supply from the plume of contamination that is traveling from the old Unisys site in Lake Success, an air stripper was installed on the property. It is efficient, treats a wider variety of contaminants and less expensive to maintain than the carbon filter.
The air-stripping tower is cylindrical in shape and filled with a “filter medium.” Although the term “waffle ball” is not very technical, it does best describe the medium for the layperson. These are small, plastic, hollow balls that are perforated to provide maximum surface area for the water that trickles down from the top of the tower. Air is blown into the tower from the bottom causing the balls to dance in a turbulent fashion. Since volatile organic compounds are the contaminants to be scrubbed from the water and since they “prefer” the gaseous state, the molecules are disbursed into the air.
The cost for the air-stripper was funded by Lockheed Martin, which purchased the Unisys property and along with that took on the responsibility for the mitigation of the plume.
During the winter months, when demand is at its lowest, the wells on Community Drive supply between 75 to 80 percent of their consumers’ water needs. During the summer months, when demand dramatically increases, these wells supply 40 percent of the community’s needs.
Only two of the three wells are pumped at one time as a precautionary measure to avoid negative consequences from over-pumping.
Redundancy is the watchword of the authority’s operational strategy. Back-ups generators for the primary generators, for example, are de rigueur.
The wells can be controlled manually or remotely off site.
When a drop of water is brought up from below, it takes about 30 minutes for it to be pumped, treated and headed off through a pipe to join up with the water main on Community Drive.
It is always important to remember that only 2.5 percent of all the water on Earth is fresh water. That is why the stewardship of limited water resources is a serious and important mission, one that everyone associated with the water authority takes seriously.