Alligators, toxic waters, mold and risk of electrocution are just a few of the myriad dangers greeting Houston residents returning to their flood-ravaged homes on Friday, as the toll of Hurricane Harvey continues to be felt long after the rains have subsided.

Even as the Lone Star State began to dry out, the stagnant water pooled in streets and drenched into carpets continued to make life perilous.

“There’s no need to test it,” Houston Health Department spokesperson Porfirio Villarreal told The New York Times. “It’s contaminated. There’s millions of contaminants.”

Simply stepping in the water posed risks.

“We’re telling people to avoid the floodwater as much as possible,” Villarreal said. “Don’t let your children play in it. And if you do touch it, wash it off. Remember, this is going to go on for weeks.”

Other officials warned household chemicals stored under sinks and in cabinets would now be mixed in with the several feet of flood waters that flowed into homes, further contaminating the area.

In many areas, streets had begun to dry out but remained clogged with soggy furniture, carpet and wood.

Health experts warned that sewage in the floodwater could make people sick and that mosquito populations could explode in the coming weeks because stagnant water offers abundant breeding grounds.

The residents of Beaumont, near the Texas-Louisiana line, lost their public water supply, and Texas’ abundance of private wells supplying drinking water also posed another problem.

Dr. David Persee, Houston’s director of Emergency Medical Services, told The New York Times, though officials were monitoring the drinking water, the well owner was ultimately responsible for ensuring the water was safe for drinking.

“In the City of Houston, we have folks that use well water but we strongly recommend against it – and this will sound awful – we don’t take responsibility for it,” Persse said.

Electrical dangers also loomed.

On Tuesday in Houston, Andrew Pasek died after he stepped into a yard where a landscape light had electrified the flood water, KTRK reported.

“They couldn’t even help my son. They couldn’t resuscitate him. He was in electrified water,” Andrew’s mother, Jodell Pasek, said.

Harvey has already claimed at least 39 lives, and rescue workers searching door-to-door knew that figure could still rise.

“We don’t think we’re going to find any humans, but we’re prepared if we do,” said District Chief James Pennington of the Houston Fire Department.

After electricity and backup generators failed at a Crosby chemical plant, temperature controls ceased to work and explosions began to spontaneously occur.

The Environmental Protection Agency and Texas environmental regulators called the health risks minimal in Crosby, but urged residents downwind to stay indoors with windows closed to avoid inhaling the smoke.

The Texas environmental agency called the smoke “especially acrid and irritating” and said it could impair breathing and inflame the eyes, nose and throat.”

In Anahuac, armed alligator farm employees took to boats to guard their flooding business, ready to stop the 350 alligators inside from making their way out, The Washington Post reported.

Meanwhile, despite food drives and donations, a Port Arthur police sergeant told The Washington Post his city was running out of food and people were continuing to pour into its shelters.

With temperatures likely to climb to the low 90s over the weekend, residents were warned about the dangers of heat exhaustion, especially for people who lost power or must toil outdoors.