10/09/2017 6:38 AM AEST | Updated 10/09/2017 6:38 AM AEST

Houston Fire Chief Warns Of Risks From Sewer Bacteria, Alligators

Residents are being encouraged to wear breathing masks.

Christopher Aluka Berry / Reuters
Houston's residents have begun the long clean up.

HOUSTON, Sept 9 (Reuters) - Houston residents attempting to return to flooded homes after Hurricane Harvey should wear breathing masks against bacteria from the city's sewers and watch for alligators and snakes, the city fire chief said on Saturday.

More than 450,000 people in Texas' Gulf Coast are either without water or still need to boil their water, a spokeswoman for Texas' environmental regulator said on Saturday. This includes parts of Houston, where flood waters had not entirely receded two weeks after the storm hit the city.

Tropical Storm Harvey brought several feet of rain over several days along Texas' Gulf Coast, causing historic floods for the continental United States. Damages could exceed $180 billion, even though power outages and wind damage were minimal along most of the coast.

City fire chief Samuel Pena, speaking at a town hall at the Westin Houston hotel on Saturday, said residents should wear breathing masks and consider tetanus shots because Houston's sewer system flooded and leaked.

Where streets have dried, sewer bacteria could become airborne, a breathing hazard. "This is a danger zone," Pena said. He also said alligators, snakes or rodents could be in homes due to flooding.

The U.S. Environmental Protection Agency and Texas Commission on Environmental Quality said on Saturday that 40 of 1,219 wastewater treatment plants were inoperable and 52 drinking water systems were not working.

That's left about 70,000 people without water because their drinking water systems were inoperable, damaged or destroyed, a TCEQ spokeswoman said. In addition, there were another 161 drinking water systems with boil-water notices serving about 380,000 people, she said.

About a third of the state's public drinking water systems, or about 2,238 systems, were affected by Hurricane Harvey, TCEQ and EPA said.

An additional 101 systems are still being assessed or their status is unknown. (Reporting By Emily Flitter; editing by Diane Craft and Cynthia Osterman)