Underground Storage Tank Closure in Florida

Underground storage tanks turn up on more Florida industrial and commercial parcels than owners expect — former fuel islands, generator day tanks, heating oil, waste oil, agricultural fuel. Frequently nobody currently at the property knows they are there.

They are also governed by their own regulatory process, separate from demolition, and that process is where redevelopment schedules go to die.

It is a regulated closure, not a demolition task

A tank in the ground is a regulated system. Taking it out of service means a formal closure with notification to the appropriate agency, a defined procedure, assessment for contamination, and documentation that closes the file.

Digging it up because it is in the way of a building pad is not closure, and doing it that way creates a problem that follows the property.

The basic sequence

Records first. Check what is on file with the county and state, and check historical aerials and Sanborn maps. Tanks that were never registered are common on older parcels, and they are the ones that cause the most trouble.

Notification. The regulator is notified in advance of the closure with the planned method and schedule.

Emptying and cleaning. Product and sludge removed, the tank cleaned, and — for anything that held flammables — rendered safe before any cutting or lifting.

Removal or closure in place. Removal is the default and generally preferred. Closure in place, where the tank is cleaned and filled with inert material, applies where removal is not feasible — under a structure, too close to a foundation, or where excavation would destabilise something.

Assessment. Soil sampling in the excavation, groundwater sampling where indicated, and laboratory analysis against applicable cleanup targets.

Documentation. A closure report submitted to the regulator.

Contamination is the branch point

If the assessment comes back clean, the closure completes and the project continues. That is the good outcome and it is common on tanks that were properly maintained.

If it does not, the project moves into a different regulatory track — further assessment to define the extent, and then remediation, monitoring, or both. That process operates on a timescale of months to years rather than weeks, and it is entirely outside the demolition schedule.

That is why the tank work belongs at the front of a project rather than in the middle. Finding contamination in week two of a redevelopment schedule is disruptive; finding it during due diligence is information.

Florida's high water table

Excavating a tank in much of Florida means excavating below the water table. That requires dewatering, and the water produced may itself need testing and controlled discharge if the tank leaked.

It also complicates the excavation physically — sidewall stability in saturated sand is poor, which means shoring or a much wider excavation than the tank footprint suggests.

What an owner should do

Before buying a property, look for evidence of tanks: fill ports, vent pipes, old dispensers, concrete patches, historic aerial photographs, and previous ownership by anyone in fuel, trucking, agriculture or manufacturing.

Before planning a demolition, do the records search and the site walk. Finding a tank at the planning stage is a manageable line item. Finding one with an excavator is a stop-work.

Budget the assessment, not just the removal. The removal is the predictable part; the assessment result is what determines the actual cost, and no honest contractor can quote that in advance.

Who does what

Tank closure is performed by contractors qualified for it, with the assessment by an environmental professional. We coordinate that work into the demolition schedule and sequence around it, because the demolition cannot proceed over an open closure — and a project planned with the tank work first is a project that finishes on time.