HOUSTON — As residents of Southeast Texas muck out their homes and pile debris on their lawns, the region is dealing with a daunting array of environmental problems.

The Environmental Protection Agency reported Sunday that more than 800 wastewater treatment facilities are not fully operational as a result of Hurricane Harvey and the ensuing floods, and that officials are aware of “releases of wastewater from sanitary sewers,” pollution that could cause health risks. The agency hasn’t had access to most of the 13 Superfund sites with toxic materials that were flooded or damaged as a result of the storm.

Thousands of people in Southeast Texas still don’t have safe drinking water, including in Beaumont, a city of 118,000 to the east of Houston. So far, the EPA has found that people who are served by 166 water systems are under boil-water orders as a safety measure and that another 50 water systems have been shut down completely.

And Sunday afternoon the Harris County Fire Marshal’s Office said executives of the disabled Arkema chemical plant in Crosby, Tex., had decided to hasten the burning of chemicals left on the site. The organic peroxides, which require refrigeration, had been exploding and burning, off-and-on, since Thursday, requiring a local evacuation. The fire marshal’s office said the company decided to be pro-active rather than wait for the rest of the chemicals to ignite.

Meanwhile, there remains too much moisture in damp Southeast Texas. The soundtrack of recovery here in the nation’s fourth-largest city is the growl of generators and the buzz of huge fans that are attempting to dry out flooded interiors. The U.S. Centers for Disease Control and Prevention has distributed 15,000 booklets urging people to be vigilant about mold, and the Federal Emergency Management Agency tweeted, “As you clean up after #Harvey, mold control is critical.”

Sunday had been designated a National Day of Prayer by President Trump, and this city’s megachurches were packed. The churchgoing was in sharp contrast to the scene exactly a week earlier, when torrential rain had submerged much of the city and thousands of people were fleeing their homes.

The recovery effort is immense in scale and benefited from some special muscle on Sunday, as NFL star J.J. Watt and fellow members of the Houston Texans franchise drove to multiple locations to deliver relief supplies gathered by Watt’s charitable foundation. Before making the rounds, Watt said Sunday that he’d originally set a goal of raising $200,000 for flood victims, but more than $17 million has come in so far from around the world. He said none of that money has needed to be spent so far. The relief supplies, all donated, had arrived Saturday in 10 tractor-trailers dispatched from the charity’s home base in Wisconsin.

“When times get tough, humans step up to help other humans,” Watt said. “Houston, we’re all with you, you have a whole team, you have a whole city, you have a whole world behind you.”

Signaling potential roadblocks to federal help for Texas, the Trump administration said Sunday that it wants Congress to attach aid for victims of Hurricane Harvey to a bill that would increase the federal debt limit. That puts the White House on a collision course with House conservatives who oppose raising the debt limit and want the Harvey money treated as a separate issue.

Treasury Secretary Steven Mnuchin said on “Fox News Sunday” that if the debt ceiling is not raised, funding to help Texas recover from the hurricane could be delayed.

“Our first priority is to make sure that the state gets money, it is critical, and to do that we need to make sure we raise the debt limit,” he said. “Without raising the debt limit, I’m not comfortable that we will get the money that we need this month to Texas to rebuild.”

If the debt ceiling isn’t raised soon, the U.S. government will not have enough funds to continue operations beyond Sept. 29, Mnuchin has told lawmakers. Appropriating emergency money to help with the Harvey response will accelerate that deadline by several days, he has said.

There is a lot of immediate need in Southeast Texas. FEMA reported Sunday that 37,000 people were in shelters across the state at latest count, with another 2,000 in shelters in Louisiana. The agency said 507,000 people have registered for disaster assistance. FEMA has moved more than 14,900 people into temporary housing. Texas officials have reported that more than 200,000 homes were damaged and more than 12,700 destroyed, according to latest estimates, which don’t include complete tallies from some of the hardest-hit areas.

Nearly 7,000 evacuees remain at the George R. Brown Convention Center in Houston, where as of Sunday some 1,700 people had received medical treatment from U.S. Health and Human Services personnel, said HHS spokesperson Joni Geels. She said that one of the biggest issues in any disaster is helping people who are already struggling with chronic illnesses.

“We’ve seen a lot of folks whose medications were damaged during the storm or lost,” she said. Many do not remember exactly what medications they were taking, or the dosage. “Sometimes the docs have to start all over and get it as close as we can.”

In addition to needing supplies, food, water and medicine, Houston-area residents also are faced with removing massive amounts of rubbish that needs to be cleared from their damaged homes.

Mattresses, carpeting, furniture, ripped-up drywall, and trash bags with ruined personal belongings sit in large piles on lawns and curbside in neighborhoods across this sprawling metropolis. The federal government will pick up most of the cost of debris removal under an amended disaster declaration from Trump, but on Sunday in some neighborhoods there was little sign that anything would be hauled away soon.

In affluent Kingwood Gardens, where homes line a golf course, sturdy fences had been flattened, exposing formerly concealed private patios and swimming pools. Inflatable alligators and inner tubes had been carried off by rushing water and now lay caught in thickets along local creeks.

FEMA administrator William “Brock” Long said on CBS News’ “Face the Nation” that Harvey should be a “wake-up call” for local and state officials. He urged them to give emergency management directors the full budgets they need to be prepared for a disaster, and said “we all have to collectively sit down after this event and figure out how to collectively improve.”

He also said FEMA is deploying resources to Puerto Rico and the Virgin Islands in advance of Hurricane Irma, which could affect those islands later this week and is on a track that could potentially take it to the East Coast of the United States. The National Hurricane Center said Sunday that it is still too early to determine if Irma will strike the U.S. mainland, but added that “everyone in hurricane-prone areas should ensure that they have their hurricane plan in place, as we are now near the peak of the season.”

In Houston, officials hope to have the city open for business as much as possible by Tuesday morning.

“I’m encouraging people to get up and let’s get going,” Houston Mayor Sylvester Turner (D) said on NBC’s “Meet the Press” on Sunday. “There is still tremendous need. Don’t want to downplay that … but most of the city is dry, and I’m saying to people — if you can open, let’s open up and let’s get started.”

Turner said the focus this week will be on “housing, housing, housing,” especially for low-income and senior residents. He praised President Trump for a “very positive” visit Saturday.

“Come and visit us in one year and I’ll show you a better city than it was before the storm,” Turner said.

On Lake Houston Parkway in Kingwood, Alspaugh’s ACE Hardware store was in cleanup mode after receiving four feet of water, but it was open for business. “ACE is open,” said a board spray-painted in red. “This store is going to be rebuilt better than it ever has been,” said owner Rick Alspaugh.

Alspaugh spray painted the top of two trailers with “God Bless ‘Merica” so helicopters could see his store from overhead. Women working to clean up had placed Texas flags in their ponytails.
“Texas pride,” Alspaugh said. “We’ll get through this.”

 Zezima and Achenbach reported from Washington. Abigail Hauslohner in Houston and Hamza Shaban in Washington contributed to this report.