Sewer systems discussed during panel meeting
The Captiva Community Panel gathered additional information regarding estimated costs if a central sewer system were to be built for island residents.
The informational meeting included many representatives from FGUA, a public utility that provides drinking and wastewater services.
FGUA Operation Manager Glenn Forrest said his staff, at the county’s request, created an overview of what would be involved in providing sewer on Captiva without disturbing the whole island. He said there are more than 400 septic tanks on the island.
Currently South Seas has a wastewater treatment plant and Sunset Captiva, Captiva Shores and Tween Waters has wastewater treatment package plants, which serve most of the southern tip of the island.
Forrest told the panel that some of the options for a new central sewer system include expanding an existing FGUA South Seas wastewater treatment plant, designing and constructing a new wastewater treatment plant and considering partnering with the City of Sanibel.
“The new wastewater plant should be located in a central area,” he said.
Some of the challenges the island would experience with building a sewer system revolve around the roadways and narrow right-aways, which would require traffic control during construction, higher road restoration construction costs and workers and materials would be trucked to Captiva for the project.
Numbers were shared during the meeting of estimated wastewater flows, which excluded the FGUA South Seas service area. Forrest said all residential, including the southern area use an estimated 123,000 gallons per day, while the central area – nonresidential – uses 13,900 gallons per day and the northern area, also nonresidential, uses 28,595 gallons per day. The total estimated wastewater flow is 165,495 gallons per day based on 637 dwelling units.
“If this program ever goes forward you will get better and tighter numbers,” he said.
According to Forrest, the estimated project cost is $15 million for 637 units, which breaks down to $23,500 per unit.
“We estimated a little over $4 million for the wastewater plant,” he said. “We factored in engineering, permitting and legal costs. We did not factor in land acquisition costs, nor did we factor in environmental mitigation costs.”
Forrest also told panel members that the homeowners would have to construct their own collection chambers at the right-away at the road.
“Typically they will be shared,” he said. “Two properties might share one collection chamber.”
Once numbers were discussed, FGUA System Operation Regional Manager Jon Meyer provided an overview of how a wastewater treatment plant works.
He said after a toilet is flushed, by gravity, the wastewater flows underneath the home through pipes, sometimes through pump stations or vacuum systems. The ultimate destination is to a wastewater treatment facility.
Meyer shared that the water is treated physically, biologically and chemically when going through the plant.
“Micro organisms is the heart of the wastewater treatment,” he said. “The objective of a plant is to flatten out the flow, especially in the morning and evening.”
The biology of the plant is also important due to the concentration of micro organisms in the system.
“We concentrate on these micro organisms and feed them oxygen, so they can feed, grow and reproduce,” he said. “The operators job is to balance the amount of waste, or food, for the amount of micro organisms with the micro organisms in the system. The micro organisms have to have time to do their job and have to have oxygen, so they can reproduce.”
Once the micro organisms go to a clarifier by flow, they enter a settling tank and travel to the bottom, allowing the clear water to go over the top and into the next portion of the treatment plant. Meyer said once the clear water goes into a chamber, chlorine is added to the water to deactivate any of the harmful organisms.
The meeting provided the panel with additional insight for further discussion of the possibility of implementing a sewer system.
Follow Meghan @IslanderMeghan on Twitter.