SPCC Compliance for South Florida Ag and Marine Operations: Choosing Secondary Containment That Survives the Rain
A secondary containment basin sized for a farm in Kansas and the same basin in Broward County are not the same tool. In South Florida, the weather does something to open containment that most spec sheets skip over: it fills the basin with rain. That single fact changes how a smart operation here should think about SPCC compliance. So before you pour a concrete dike or buy a single wall tank to sit inside one, it is worth understanding what the rain, the salt air, and Florida's own tank rules do to your options.
The rain is the real design problem
South Florida averages about 52 to 53 inches [132 to 135 cm] of rain a year, and roughly three quarters of it falls in the wet season. That is the long term normal. The extremes are worse. In April 2023, Fort Lauderdale took around 25 inches [64 cm] of rain in about 12 hours. In June 2024, parts of the region saw close to 28 inches [71 cm] over a few days. Florida also records more thunderstorm days than any other state, and hurricane strikes hit the coast on a regular cycle.
Here is why that matters for containment. An open basin sized to hold 110 percent of your largest tank is only holding 110 percent when it is empty. Let a wet season storm drop several inches of water into it, and the usable spill capacity you paid for shrinks. Worse, before your team can pump that water out, it has to be checked for contamination. If a valve drip or a small leak reached that water, the whole pooled volume can be treated as hazardous wastewater, and now you are paying to haul it away.
We break the full cost of that cycle down in our Industrial Poly Double Wall Tanks: A Secondary Containment Guide. The short version for South Florida: an open basin is a rain collector, and here it rains a lot.
Florida stacks two rulebooks, not one
Most guides only cover the federal rule. In Florida you answer to two.
Federal SPCC (40 CFR Part 112). If your facility stores oil above the federal threshold and a spill could reach navigable waters, you need an SPCC plan and secondary containment. As a general benchmark, that containment is sized to hold 110 percent of the largest container, with room for rainfall. You can read the rule itself at the federal eCFR.
Florida's own state rule. The Florida Department of Environmental Protection regulates aboveground petroleum and regulated substance storage tank systems larger than 550 gallons [2,080 L] under Chapter 62-762 of the Florida Administrative Code, and underground tanks larger than 110 gallons [416 L] under Chapter 62-761. The state rule spells out that regulated storage tanks must have secondary containment, and that the containment material has to be impervious to what you store, non corrosive or corrosion protected, and able to hold up to outside conditions. Mineral acid tanks such as sulfuric, hydrochloric, and phosphoric acid over 110 gallons are covered by the rule as well. You can confirm current requirements on the FDEP storage tank compliance page and in Chapter 62-762.
Florida is not the only state with a second layer. California runs a similar program, the Aboveground Petroleum Storage Act, which ties state oversight to the federal SPCC plan and can require secondary containment even at conditionally exempt farms, as noted by the California Office of the State Fire Marshal. Wherever you operate, federal SPCC is the floor, and coastal states with heavy rain and shallow groundwater tend to build on top of it.
Three things South Florida does to your containment choice
1. Rain and storm surge overwhelm open basins. Covered above. In a climate that can deliver a season's worth of trouble in a single afternoon, an open dike spends much of the year doing double duty as a pond, and your team spends that time testing and pumping it.
2. Salt air and a high water table attack the containment itself. Coastal and marine sites sit in salt laden air that speeds up corrosion of steel, protective coatings, and the lower tank chime where the wall meets the floor. Florida's rule already requires containment to be impervious and corrosion resistant, which is a harder promise to keep with an open concrete dike that cracks, traps wet salty debris at the tank base, and needs recoating, than with a sealed tank that keeps weather off the primary vessel in the first place.
3. Two different buyer worlds, one containment question. Inland, the ag belt stores liquid fertilizer, UAN solutions, and crop protection chemicals. On the coast, the marine and Port Everglades corridor stores fuels, oils, and process chemicals. The chemicals differ, but the question is the same: keep a spill off the ground and out of the water, every day of the year.
For most South Florida sites, a double wall tank is the cleaner answer, and the reason is simple. It is sealed. Rain cannot enter the outer shell, so the containment capacity you bought stays intact through the wet season, and the compact footprint frees up yard space. For a full chemical by chemical and facility by facility walk through, use our facility selection guide.
Open containment is not always wrong. It can still make sense for very large field erected tank farms where one engineered dike serves many tanks, for sites that already have a well built and well maintained dike in place, or for certain fuel and oil layouts. The point is to choose on purpose, based on your site and your rainfall, not by habit.
Double wall or open containment here?
For most South Florida sites, a double wall tank is the cleaner answer, and the reason is simple. It is sealed. Rain cannot enter the outer shell, so the containment capacity you bought stays intact through the wet season, and the compact footprint frees up yard space. For a full chemical by chemical and facility by facility walk through, use our facility selection guide.
Open containment is not always wrong. It can still make sense for very large field erected tank farms where one engineered dike serves many tanks, for sites that already have a well built and well maintained dike in place, or for certain fuel and oil layouts. The point is to choose on purpose, based on your site and your rainfall, not by habit.
The overfill gap most people miss
A double wall tank contains a leak from the inner tank. It does not catch an overfill that sprays out of the vent, or a spill at the fill connection during a delivery. Florida's rule reflects this reality directly: tanks loaded by truck need spill containment at each fill point, tanks generally cannot be filled past 90 percent, and overfill alarms or gauges are required.
So treat venting and overfill protection as a separate line item, not an afterthought. Our chemical tank venting guide covers how to size and place venting so pressure and overfill events do not become spills.
Picking a tank for South Florida ag and marine
Match the tank to two things: the specific gravity of your chemical, and the volume you store.
For a smaller, aggressive chemical day tank, a vertical double wall unit like the 750 gallon double wall tank built for sulfuric acid [2,840 L] keeps a corrosive product fully contained in a small footprint. For bulk storage of heavier solutions, a large unit like the 10,000 gallon Captor double wall tank rated to 1.5 specific gravity [37,850 L] carries volume without a separate basin. To compare the full range, browse our double wall chemical storage tanks.
A South Florida picture: ag inland, marine on the coast
Our Pompano Beach branch sits between the two containment worlds. To the west is the inland ag belt. To the east is the marine and Port Everglades corridor.
Picture an inland grower storing liquid fertilizer. An open dike around those tanks would fill during the first serious wet season storm, and every inch of trapped rain would mean testing before it could be drained. A sealed double wall tank removes that whole chore, because the rain never reaches the containment space.
Now picture a coastal service company storing process chemicals near salt air. It faces both problems at once, the rain and the corrosion. A double wall tank keeps the weather off the primary vessel and keeps the containment surface sealed, which is exactly what Florida's material rules are asking for.
In both cases the operation stays inside the federal SPCC line and the Florida 62-762 line, with less maintenance and less risk. If you run an ag or marine operation in South Florida, the Pompano Beach team can help match a tank to your chemical and your site. Talk to the Pompano Beach branch.
Quick decision checklist
- Do you store more than the federal SPCC or Florida 62-762 threshold? If yes, you need compliant secondary containment.
- Is your site exposed to heavy rain or salt air, meaning most of South Florida? Favor a sealed double wall tank over an open basin.
- Do you already run a well maintained engineered dike serving many tanks? Open containment may still fit.
- Have you handled overfill and fill point spills separately? Add proper venting and overfill protection.
- Not sure which tank matches your chemical? Use the selection guide or ask the Pompano Beach branch.
This guide is general information, not a compliance certification. SPCC plans for non qualified facilities must be certified by a licensed Professional Engineer. Confirm your obligations with a qualified professional.
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