Water foul? Blame the  drought By Joe  Bauman Deseret News staff writer          Residents of Salt Lake City's east  bench can blame the drought for another side effect: tap water with a mossy  smell and a slight tang.          "It's not going to impact people's health.  It's just causing taste and odor," said Florence Reynolds, city water quality  administrator.          Not that it's like living in a swamp, but the culinary  water isn't spring fresh. It has a miniscule, harmless component of algae.          Utah's drought, currently in its fourth year, has dropped Deer Creek  Reservoir to such low levels that algae are thriving in the pond.          Low water, high temperatures, a lot of summer sunshine and concentrated nutrients in  the reservoir have created great growth conditions for algae, Reynolds explained. The nutrients aren't more common, but as water decreases their concentration goes up.          As the tiny plants grow and die, they excrete a compound called geosmin. The material is responsible for flavoring and smelling  up water "at extremely low levels," she said.          LeRoy Hooton, the city's  director of public utilities, said the impact is greatest in areas that receive  Deer Creek water more directly from the Salt Lake Aqueduct, such as the east bench. In the Avenues, water is mixed more with other sources and residents are not complaining.          Water treatment plants are adding activated carbon to absorb some of the odors, Reynolds said. As Deer Creek water is mixed with other  water sources, the level of geosmin drops and the effects disappear.          The smells and tastes may decrease over the next couple of days, according to Reynolds. E-mail: bau@desnews.com