Most of that excrement sits in open-air pits, known as "lagoons", which blanket the landscape of North Carolina just inland from the coast.
Meteorologist say conditions will deteriorate throughout the day Friday.
With recent official reports finding that last year's Hurricane Maria claimed almost 3,000 lives in Puerto Rico-an assertion that re-emerged onto the national spotlight Thursday after President Donald Trump, without providing evidence, alleged that those estimates were artificially inflated and politically motivated-it's worth exploring what it is that ultimately kills people, including the most vulnerable, when a hurricane strikes.
Florence's top winds were clocked on Thursday at 100 miles per hour (170 km per hour) as it churned in the Atlantic Ocean, down from a peak of 140 mph (224 kph) earlier this week when it was classified a Category 4 storm. Then it is likely to hover along the coast Saturday, pushing up to 4m of storm surge and unloading water on both states.
The National Hurricane Center said the storm would dump as much as 30 to 40 inches (76-102 cm) of rain on the southeastern coast of North Carolina and part of northeastern SC, as well as up to 10 inches (25 cm) in southwestern Virginia. At least four people were killed.
Florence dipped to Category 2 hurricane strength with maximum sustained winds of 110 miles per hour on Wednesday evening.
Cooper said Florence was set to cover nearly all of North Carolina in several feet of water.
Forecasters continue to warn of storm surges, excessive rainfall and catastrophic flash flooding.
"This storm is relentless and excruciating", North Carolina Governor Roy Cooper told CNN late on Friday.
In Jacksonville, North Carolina, next to Camp Lejeune, firefighters and police fought wind and rain as they went door-to-door to pull people out of the Triangle Motor Inn after the structure began to crumble and the roof started to collapse. It was forecast to make landfall on Friday morning or afternoon near Cape Fear, North Carolina, bringing up to 40 inches (1 meter) of rain in places.
In New Bern, population 29,000, flooding on the Neuse River trapped about 200 people.
The city of about 29,000, which was founded in the early 1700s and was briefly the state capital, is near the North Carolina coast and is bordered on the east and south, respectively, by two rivers.
Mayor Beach Mayor Brenda Bethune told CNN traffic out of the SC city has more than quadrupled as residents and visitors evacuate.
About 800 flights in the region have been canceled ahead of the storm, CNN reported. As Florence moves inland, we'll see more rain and more flooding from our rivers.
North Carolina, South Carolina, Virginia, Maryland, and Georgia have all declared states of emergency over the storm.
President Donald Trump said Wednesday that protecting lives is his "absolute highest priority".
But the storm still carried "very unsafe winds", the Center added.
The National Hurricane Centre (NHC) says that despite the gradual lowering in wind strength, the storm remains extremely risky because of the high volume of rainfall and storm surges predicted.
Further south, just north of South America, is where you'll find Tropical Storm Isaac, a system packing maximum winds of around 65 km/h.
Total inundation is likely in portions of eastern and southeastern North Carolina and perhaps the upper part of the SC coast with a storm surge in excess of 10 feet in some areas.
The full impact of the storm surge on the coast will depend on whether the storm's arrival coincides with high tide. The warning is issued 36 hours in advance of the anticipated onset of tropical-storm-force winds.