A new water pump was installed Wednesday afternoon in Greenville's treatment plant, but the state Department of Environmental Protection is still advising residents to boil their water and conserve it for at least a week.

"Even though the water tested within drinking standards Monday, it was cloudy, which is usually a sign of solids in the water," said Freda Tarbell, DEP spokesperson. "Because the situation was fluid, we didn't want to take any chances."

The possible risk she was referring to is contamination by E. coli, giardia or cryptosporidium. Boiling the water for 3 minutes kills those bacteria, all of which can cause illness, DEP said in a news release.

Greenville's water woes began last week, when a water pump broke down. A backup rental pump, which was brought in Oct. 30 to hold things together until a new pump could be installed, allowed debris to get into the filtration system.

That meant Greenville Municipal Authority workers had to shut down the treatment plant to clean the clarifiers and water-intake channel. When they did that on Monday, the water level dropped to dangerously low levels, prompting the DEP to order the boil-water advisory and call for authority customers to conserve.

The situation worsened when the new pump installed Monday malfunctioned because of debris still in the system, said Bill Brady, authority superintendent.

By Monday evening, classes had been canceled for Tuesday at Greenville and St. Michael's schools and the Army Reserve had trucked in drinking water.

But things were looking better by Wednesday.

"The clarifiers are flowing now and we're getting ready to fire up the new pump again," Brady said, adding that the water level in the west-side storage tank rose from 4 feet Tuesday night to 11 feet Wednesday morning and the level in the east-side tank was at 30 feet.

Despite the improvement, water authority customers are urged to continue boiling water for 3 minutes before using it for any kind of consumption, Ms. Tarbell said.

Besides drinking, consumption includes washing fruits and vegetables, brushing teeth and making fruit juices and ice cubes, according to the DEP news release.

Ms. Tarbell said unboiled water is safe for bathing, doing laundry and washing dishes, although the news release noted all dishes should be dried completely after washing. "It should be perfectly fine to use in these instances," she said.