Rain, increased algae cause natural variations
Fort Wayne City Utilities water customers may have noticed an odd taste or smell in their water during the past few days. The water is safe to use for drinking, cooking and all other purposes despite the change in taste. Changes in taste and odor in the water are common, and typically do not indicate that the water is unsafe.
“Fort Wayne’s drinking water consistently exceeds quality standards from the Environmental Protection Agency,” said Mayor Tom Henry. “The increased taste and odor of the past week are part of a natural process and not a concern for the health and safety of the drinking water supply for City Utilities customers. City Utilities provides a consistently safe and reliable source of drinking water for our homes, schools, industry and businesses.”
Taste and odor in drinking water may occur after heavy rains wash sediment and organic material such as twigs, leaves or grass into the water source. The source of Fort Wayne’s drinking water is the St. Joseph River which received a large amount of runoff during heavy rains last week. When the organic material in the river begins to decay, the process of treating drinking water may result in water with an increased taste or odor.
Runoff may also carry nutrients such as nitrate and phosphorus that can encourage the growth of naturally occurring algae in the river. Algae growth increases during hot weather and can also cause a taste or odor that is removed during the treatment process.
The Fort Wayne Water Filtration Plant uses powdered activated carbon (PAC) to control taste and odor. The carbon is added to water during the treatment process and is removed before the water leaves the plant. Currently the plant is using the maximum effective dose of PAC – 150 pounds per million gallons of water – but even this maximum dose may not completely control the taste and odor.
The laboratory at the Plant tests for taste and odor. Results are reported as a Flavor Profile Number or FPN. The FPN scale is from zero to eight. The Filtration Plant has a goal of keeping the FPN at six or lower. Fort Wayne’s FPN last Friday was six; today the FPN is four. FPN is reported weekly on Friday and may be found on the City’s Web site and on the water quality hotline at 427-2297.