MEMPHIS, Tenn. — Memphis residents spent their fourth day boiling water as repair crews continued to fix broken pipes amid winter storms that have been blamed for dozens of deaths across the United States.

The city's water company, Memphis Light, Gas and Water (MLGW), had expanded its boil water notice on Friday to the more than 600,000 people it serves after a number of water main breaks, creating a risk of harmful bacteria contaminating the water supply. The advisory came amid a stretch of freezing temperatures and dropping water pressure for many Memphis and Shelby County residents.

On Monday morning, the city-owned utility lifted its water conservation request for all customers after MLGW said water pressures across the city are in the process of returning to normal. But the boil advisory remained in effect.

"Over the past week, MLGW has located and repaired more than 56 broken water mains, responded to more than 4,000 customers, residential and commercial, that reported broken pipes and shut off nearly 100 fire suppression systems to keep them from bursting or to help limit the damage from already broken pipes," MLGW said in a news release.

Residents — who were already struggling with a week of sub-freezing temperatures, snow, and ice — expressed frustration over the city's water issues. Some restaurants and bars were also forced to serve bottled water to customers on Sunday while others remained closed or changed their menus, citing the water issue.

"It’s frustrating for us homeowners, especially old folks, to have to deal with the snow and the water problem," 81-year-old William Wilkerson, who lost all water service between Thursday and Sunday, told The Associated Press.

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Memphis water company begins water testing

Memphis' conservation order went into effect Thursday, with MLGW asking customers to avoid using non-essential water due to leaks and low pressure in various areas of the water network. A boil water advisory was announced that day in those low-pressure areas.

A day later, the utility announced a boil water advisory for the entire city as pressure fell below the 20 psi threshold that MLGW CEO Doug McGowen said the utility is required to maintain.

With pressures returning to that level, MLGW said Monday it has begun sampling water for testing. Those samples will have to "incubate 18-24 hours before results are available." Once those results are in, MLGW will send them to the Tennessee Department of Environment and Conservation to confirm that it is safe to drink.

If the state department gives MLGW the "all-clear," the utility will lift the city-wide boil advisory. MLGW also advised that water might be "discolored" as pressure is returned across the system, due to sediment in the water, and recommends people to run their water until it is clear.

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Deep freeze across U.S. expected to subside

Much of the United States has faced a deadly and dangerous deep freeze this January, which contributed to over 90 deaths mostly caused by hypothermia or road accidents. But the cold is expected to ease up this week, with temperatures forecast to be above-average.

The series of winter storms and days of below-freezing temperatures caused water problems for cities in several states, including Tennessee, Arkansas, and Mississippi.

Memphis was the largest water system in Tennessee to experience problems from the cold weather. The Tennessee Emergency Management Agency said Sunday that 28 water systems were under boil water notices and 17 counties were reporting operational issues with their water utilities.

Contributing: Doyle Rice, USA TODAY; The Associated Press