Even as Texas continues to marshal crews to handle Hurricane Harvey debris, Irma's move up the west coast of Florida promises to stress the effort and leave a combined bill near or topping the multi-billion dollar tab for Katrina, the largest to date.
Officials insist they can manage two large cleanups at once.
Throughout the weekend, disaster specialist AshBritt Inc, DRC Emergency Services and waste haulers including Waste Management and municipal crews brought to Houston, were carting Harvey's rubble to dozens of Texas landfills.
Texas disclosed about $US136 million in federal funds were released to pay for initial efforts around Houston.
The city's mayor, Sylvester Turner, had issued a call for heavy equipment operators to help, but a spokesman said the city has 64 crews at work or soon to arrive, "all the help we need."
"It's going to stress the industry from an equipment standpoint," John Sullivan, chief executive of DRC Emergency Services, said of the two Category 4 storms.
His company will split specialised vehicles between Texas and Florida, relying on subcontractors with their own equipment.
Clearing Texas's debris will take four to six months, he said.
After Hurricane Katrina hit in 2005, the cleanup took about a year, said Hugh Kaufman, a retired EPA solid waste and emergency response analyst.
The overall bill for Katrina was $US2 billion, the largest to date, spanned several states and the demolition of the more than 23,000 homes in the New Orleans area alone. He thinks the combined clean-up tab will top Katrina's.
The Gulf Coast bill "is going to be worse," estimated Kaufman.
While Irma's shift west and weakening winds helped reduce its impact and likely bill, "There are a lot of question marks to know what the exact cost will be," he said, as the storm brings rain and wind to Georgia.
Texas' tally of the cost of debris removal by affected counties from Harvey on Monday totalled $US118 million, but many communities haven't yet provided estimates.
Houston estimates the city's clean-up bill alone will run to $US200 million.
The scale of the effort isn't reassuring to residents living alongside the mess. Houston's fire chief has advised residents in severely affected areas to get tetanus shots.
"Our trash pile has been at our curb for going on two weeks and they aren't telling us when it's going to be picked up," said Melissa Brewer, of Katy, Texas.
Meanwhile, smaller businesses looking to hire crews for trash removal in Texas said Irma is affecting availability.
"Everyone's shooting down to Florida," said Marcel Yanez, a Missouri contractor who visited Friendswood, south of Houston, for potential work.
"The price point is higher," he said.
Larger companies are reopening closed Texas facilities.
"Our landfills are doubling in volume," said Marcel Darby, an operations director for Waste Management, which is running its landfills seven days a week.
Residents say all the three major floods that hit Texas in recent years has given companies and officials the experience to move trash away quickly.
"They have had enough practice that they're getting quite efficient at it," said Bellaire, Texas, resident Mike McCorkle.
He took a break from repairing his home to gaze at the mountain of debris lining his street. "I think they'll need to do it fast because those trucks will be needed in Florida very soon."