MEMPHIS, Tenn. – Germantown residents remain without safe tap water as they wait for officials to test more samples one week after they announced the city's water supply was contaminated with diesel fuel.

Residents in the Memphis suburb of over 40,000 were first told about the diesel leak and water contamination on July 20 and advised not to consume the city's tap water, or use it for bathing or washing.

Since then, residents have descended on water bottle distribution sites and some restaurants have dramatically reduced their menus to only include items that can be prepared without tap water.

There is no timeline for when the water nightmare will be over, officials said. As the city flushes out its water distribution system, residents and businesses are being told to only use bottled water for everything besides flushing the toilet.

The water crisis in Germantown comes about one year after residents across the state line in Jackson, Mississippi, entered a state of emergency when a flood shut down the city's largest water treatment plant, leaving residents without running water. The state of emergency lasted from August to November 2022.

Germantown officials continue water testing

In Germantown, officials said Tuesday some tests of water samples were coming back clean. But that doesn't mean water usage restrictions will be lifted anytime soon, City Administrator Jason Huisman said.

"The order to use water only for flushing toilets remains in place until the city's entire water main distribution system has been flushed and cleared," Huisman said in a YouTube video.

The flushing process for the entire system started Tuesday, Germantown officials said.

How did diesel contaminate water in Germantown?

Germantown first advised residents not to consume the city's tap water last Thursday after a few residents reported their tap water had a strong odor. The city's water department determined a generator – which was powering the Southern Avenue water treatment facility during a power outage – had been leaking diesel fuel into an underground reservoir.

Health department warns of contaminated water effects

On Monday, Germantown Mayor Mike Palazzolo said officials had not yet begun investigating what caused the diesel leak. The Shelby County Health Department warned residents and businesses not to consume the city's tap water or use it when cooking.

The department told some restaurants in Germantown to prepare food items staff can make using only water from bottled water supplies.

The city of Germantown also told residents that boiling the contaminated water will not make it safe for consumption.

This week residents flocked to a water distribution site at an elementary school, causing a traffic jam. At the Forest Hill Elementary School, nearby roads were backed up and police asked residents to avoid the area unless they were there to pick up water bottles.

As the city works on pumping all the contaminated water out of its system, the health department said that bathing in and consuming diesel fuel can lead to health issues.

"If swallowed, diesel can cause nausea, vomiting, and diarrhea. Skin exposure can cause skin irritation, blisters, and peeling," the health department said.

River also contaminated with diesel

Monday night, Palazzolo said some of the contaminated water is being fed back into the Wolf River. While diluted, the water still makes its way back into the water system down the river, Palazzolo said.

The Wolf River Conservancy is working with the Tennessee Department of Environment and Conservation to determine the possible environmental hazards of having contaminated water enter the river, director Keith Cole said. Palazzolo said Monday that the Department of Environment and Conservation has not laid out what levels of diesel would cause concern.

Some residents have turned to social media, demanding to see results from past and future water testing. Others say they want to know why parts of the city are being allowed to use tap water and what exactly Germantown and state officials mean when they say water is "safe." Palazzolo said that water is deemed "safe" when there are no traces of diesel found.

Brooke Muckerman reports for the Memphis Commercial Appeal and Claire Thornton reports for USA TODAY.