"North Carolina allows all this risky waste to be stored next to its flooding coastal - and, for that matter, inland - rivers", Frank Holleman, a senior attorney at the Southern Environmental Law Center, told the Raleigh News & Observer.
The Cape Fear River is still slated to crest in the coming days.
In Anson County, east of Charlotte, a train derailed on Sunday evening, but it wasn't clear whether it was storm-related or if anyone was injured.
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.
Addressing roughly 10,000 people who remain in shelters and "countless more" staying elsewhere, Cooper urged residents to stay put for now, particularly those from the hardest-hit coastal counties that include Wilmington, near where Florence blew ashore on Friday.
"This is an epic storm that is still continuing", Cooper told a news conference. Others got a case of bottled water or military ready-to-eat meals.
"What we are the most concerned about is, we have five major rivers that surround us, and we only have one major road into Myrtle Beach, but all of our major roads are going to be affected by this flooding within the next three to seven days", she said.
"At this time, things are moving as well as can be in the city", he said. The smell of cracked pine trees wafted through hard-hit neighbourhoods.
Tens of thousands of houses have been damaged, but for many parts of the Carolinas, "the worst is yet to come" as river levels rise to historic levels, said Zach Taylor, a meteorologist with the US National Weather Service. Trump said nearly 20,000 military personnel and federal workers were deployed to help with the aftermath of Florence in the Carolinas and the Mid-Atlantic, and they would "do whatever it takes to keep the American people safe".
At least 32 people have been killed by Florence, including 25 in North Carolina and six in SC. Harvey's total of 60.58 inches (153.87 centimeters) a year ago in Texas is No. 1.
Desperate for gas to run a generator at home, Nick Monroe waited in a half-mile-long (.8 kilometer-long) line at a Speedway station even though the pumps were wrapped in plastic. His power went off on Thursday before Florence hit the coast, but he couldn't recall exactly when.
"It's all kind of a blur", said Monroe, the sky overhead sunny and bright after the rain finally stopped.
Forecasters said it was expected to gradually pick up forward speed and complete a big turn toward the Northeast, which is in for as much as 6 inches (15 centimeters) of rain.
Signs on a flooded highway leading out of town said "ROAD CLOSED", and many streets that weren't flooded were blocked by fallen timber.
Waggoner reported from Raleigh, North Carolina.
The death toll climbed by two as authorities found the body of a 1-year-old boy who was swept away after his mother drove into floodwaters and lost her grip on him while trying to get back to dry land. Authorities in Virginia said one person was dead after an apparent tornado.
Flooding worries increased in West Virginia and Virginia, where roads were closed and power outages were on the rise.
Over 4,300 homes in New Bern, North Carolina, were damaged or destroyed, and over 300 businesses suffered the same fate, according to City Manager Mark Stephens.
Thousands of rescues have taken place in the two states and over 650 people were taken to safety in and around Wilmington, North Carolina, said Barbi Baker, a spokeswoman for New Hanover County.
Florence, now an elongated low pressure area which continues to produce heavy rain over portions of the Mid-Atlantic States, is expected to transition into an extra tropical cyclone, the US National Hurricane Center (NHC) said late on Monday. Radar showed parts of the sprawling storm over six states. Officials warned that more twisters could form imminently.
"We're going to be OK", Saffo said.