In north Florida, the pipeline will run through conservation areas, under rivers, near springs, and sinkhole-vulnerable karst geological areas.

The hotly-debated Sabal Trail natural gas pipeline has received its final federal permits and company officials are seeking a green light to start construction by Wednesday along a 516-mile corridor that includes environmentally sensitive parts of north central Florida.

By Friday afternoon, the Federal Energy Regulatory Commission had already approved a request to start construction on a connector pipeline that will carry natural gas from the station in Osceola County where Sabal Trail will end to a Florida Power & Light natural gas plant in Martin County.

Sabal Trail secured the final permits Thursday to seek authorization to start construction.

That’s when the U.S. Army Corps of Engineers finalized permits that allow the companies partnering on the pipeline — Houston-based Spectra Energy, Duke Energy and FP & L parent company NextEra Energy — to discharge dredged and fill material into water bodies, such as wetlands, during construction.

The permit requires the Sabal Trail partnership to buy credits from several federal- and state-approved wetlands mitigation banks. Those banks are wetland areas that have been preserved or restored on the premise they offset the impact to wetlands from construction of projects the Army Corps has permitted.

Last fall, the U.S. Environmental Protection Agency estimated some 1,200 acres would be destroyed or impacted during construction. The EPA later reduced that projection to less than 900 acres but later made a 180-degree turn and dropped significant environmental concerns over the project that included whether the potential for sinkholes and damage to the aquifer had been downplayed by Sabal Trail and the Federal Energy Regulatory Commission.

In some cases, the impacts to wetlands are considered temporary, even though areas could take up to 50 years to revegetate.

In north central Florida, the pipeline's route will cross under the Suwannee River and Lower Santa Fe River and go through dozens of springsheds, including near Rainbow Springs, and through wooded conservation lands and karst geology prone to sinkholes and characterized by underground caverns.

The full Sabal Trail project is a $3.2 billion, 516-mile, 3-foot-wide pipeline that will carry up to 1 billion cubic feet of natural gas a day from Alabama through south Georgia and Florida to the connector pipeline in Osceola County.

In Florida, the pipeline will run through rural and wooded areas of Hamilton, Suwannee, Gilchrist, Levy and Marion counties as well as a small piece of Alachua County. The pipeline will continue through Sumter, Lake and Orange counties to hook up to the pipeline that will run from Osceola County to the FPL natural gas power plant in Martin County. Another smaller pipeline that is part of the larger project will supply a Duke Energy natural gas plant in Citrus County.

Merrillee Malwitz-Jipson of the Sierra Club vowed via text Friday evening: "We will use all legal means necessary to stop this fracked gas pipeline."

Pamela Smith, president of Our Santa Fe River Inc., wrote in an email that "...there is no win for the citizens of Florida, only profits for the energy companies that will move compressed gas through our delicate and already overtaxed water ecosystem."

With permits in hand, the companies behind Sabal Trail applied to FERC to start construction on or before Aug. 17. FERC already approved the pipeline project in February and now is looking at whether the companies behind Sabal Trail met all conditions of that approval before green-lighting construction.

In an email, Spectra Energy spokeswoman Andrea Grover gave a target date of “late August” to start construction. She said the more than 500-mile route will be divided into five segments and construction on each will start simultaneously.

The company is engaged in authorized pre-construction activities such as surveys and gopher tortoise trapping and relocation, Grover wrote.

Already, pipe is being stored in an area north of Lake City, a fact made public by the WWALS Watershed Coalition, a south Georgia and north Florida group opposed to the pipeline project. The group argued that the storage yard was not an allowed pre-construction activity.

Grover wrote that a transportation contractor leased the storage yard to move “the pipe from the pipe mill to a location closer to the project to temporarily store pipe.”

The Army Corps of Engineers did not grant a request from the Madison County Commission in north Florida to further review potential environmental impacts of Sabal Trail's main line, including “a site inspection to determine the actual proximity of active sinkholes and other features of the aquifer and cave systems to the proposed pipeline route,” records posted on the WWALS Watershed Coalition Web site showed.

Madison County commissioners noted that the pipeline passes through neighboring Hamilton County near the Withlacoochee River and expressed concerns about potential pollution to the river, area wells and Madison Blue Spring, either from construction or a possible pipeline leak later.

The U.S. Army Corps of Engineers declined the commission's request, saying information already gathered about the project is sufficient for them to make an accurate evaluation.

A few months back, the Marion County Commission also raised concerns about the potential impact to the headspring of Rainbow Springs, impacts to the underground karst network through which groundwater flows, the potential for sinkholes and possible damage to wetlands and harm to the threatened or endangered species living in the area of the Marjorie Harris Carr Cross Florida Greenway that the pipeline will cross.

The pipeline route passes through a small area of Alachua County. The Alachua County Commission did not take a formal stance to oppose the pipeline, Commissioner Robert Hutchinson said.

Environmental groups have organized in opposition to the project, but it has now received all required state and federal permits in Florida.