By Brian Sherman, The Island Eye News Managing Editor
It’s been well over half a century since the residents of Sullivan’s Island shelled out less than $1 million to build the town’s first and only wastewater treatment plant.
A complete overhaul of the ancient plant on Gull Drive will give the town a state-of-theart facility that can stand up to hurricanes and earthquakes, and, as an added bonus, give the Water & Sewer Department a safe and dry place to store its valuable equipment.
Of course, the price tag will be a bit heftier than it was in 1968. The $16.3 million project, which got underway in November 2019, will be paid for by the town’s 2018 installment purchase revenue bond.
The town held its official groundbreaking for the project March 13, and work is scheduled to be completed by May 30, 2021.
Mayor Pat O’Neil spoke during the brief ceremony, and representatives of the project engineer – HDR of the Carolinas – and contractor – Garney Construction of Winter Garden, Florida – also were on hand.
The town had little choice but to overhaul the aging plant, which has undergone two upgrades during its lifetime but nothing anywhere near the scope of the current project, according to Water & Sewer Department Manager Greg Gress.
“Many of the key components have reached the end of their useful life,” said Gress, who has been with the department since 2001. “Similarly, much of the sewer collection system was installed at this time to complement lines installed as early as the 1930s.”
The town is also spending $4 million to upgrade five lift stations and is finishing up phase II of a $4.5 million project aimed at reducing inflow and infiltration into the
sewer collection system.
Work at the treatment plant site will include: revamping the influent pump station and converting to a submersible pump that can withstand flooding; building a new head works, where bulky items are separated from the sewage coming into the plant, and elevating it above the flood plain; replacing the oxidation ditch and adding a second tank so the department can take care of required maintenance on one tank while the other remains in use; moving the electrical control panels that operate the clarifiers above the 100-year flood elevation; adding a large building that will store the department’s equipment and include a generator that will run the entire plant; and renovating a building to provide office space and showers for employees.
Currently, the only place chemicals are used is in the chlorine contact chamber. At this point, the clear liquid is treated with chlorine gas and sulphur dioxide gas before it leaves the plant for the marsh in a 300-foot-long, 12-inch pipe. When the work on the plant is completed, the liquid will be treated with tablets rather than gas.
Gress pointed out that the concrete structures, sitting atop 121 pilings sunk 77 feet into the ground, will be able to withstand heavy winds and even an earthquake. He said the new plant should have a life span of 50 to 70 years. Since there is a finite amount of land on Sullivan’s Island, he expects the wastewater treatment plant to handle the town’s needs for another half century or more.
“There won’t be much growth here,” he said.
Since septic tanks are not permitted, the treatment plant serves the entire island.
Sometime prior to 1968, the military built a sewage collection system that served part of Sullivan’s Island. Until 1968, Gress pointed out, the remainder of the town depended on a few pump stations that sent raw sewage directly into the marsh.
The island’s first treatment plant was built by W.F. Brinkley & Son, with Cummins & McCrady serving as the architect and engineer. The total cost, less than $1 million, included work on the collection system as well.