An estimated 80,000 people in the Fairfax City area have algae in their water that affects its odor and taste, but officials said yesterday that the water is safe.

"We have been making tests all week to make sure about the water -- the bacterial levels are down in the acceptable range," said Tom Welle, a spokesman for the Fairfax City Water System. "The water is safe."

He said the problem developed when Goose Creek in Loudoun County, a primary source of water for Fairfax City, parts of unincorporated Fairfax County, Herndon and Sterling Park, dropped to below-normal levels because of the lack of rain. "It is nearly dry," Welle said. As a result, water flowing from an adjacent reservoir through the creek to a nearby treatment plant has picked up "a lot of junk from the bottom of the creek -- algae, dead leaves, manganese," Welle said.

Customer complaints about the water increased yesterday.

"It is nauseous," said Shirley Staples, a Fairfax County resident. "Even tea doesn't cover up the taste."

Staples, who has three children, said the last time her water was this bad was during a water shortage. "The reservoir was low that time, too," she said.

But she said her main concern was whether the taste and smell were signs that the water is hazardous. "I would like to be assured that it is safe to use," she said.

Welle said customers shouldn't worry about safety. However, he also said that the city can't do anything about the smells and the odors that are bothering users. Here is the explanation:

When Fairfax City was no longer able to draw water from Goose Creek to meet customer demand, officials unleashed the backup supply they have in the Beaver Creek Reservoir, which is separated from Goose Creek by a dam. Goose Creek normally holds 32.5 million gallons of water. Beaver Creek Reservoir typically holds 1.3 billion gallons, but its damned-up water is stagnant.

"Because of the nature of the water -- it is stagnant and [and picking up material from] the bottom of Goose Creek -- there is nothing we can do about odors or tastes," Welle said. "We can't do anything until we go back to Goose Creek water . . . and we can't do that until it rains.

The city is doing something about the excess manganese that the water has collected from the bottom of the creek, however. The water plant, which treats 11 million gallons of water on an average day, now adds potassium permanganate to the water.Welle said the potassium permanganate attracts the manganese and forces it to settle to the bottom before the water is distributed to customer homes and businesses.

Until the middle of this past week, the Fairfax City water also was being piped to customers in Reston. But the Reston supply now has been switched and residents there are getting water from Fairfax County's Occoquan Reservoir.