PALESTINE, Texas (Feb. 15, 2017) – The following are some frequently asked questions on Geosmin, the compound causing the taste and odor issues with City of Palestine Water.
What is causing the taste and odor experienced by some customers served by the City of Palestine?
The City of Palestine Water is collected from the Neches River. Due to the unseasonably warm weather, an extreme amount of Geosmin has been detected in the raw water. Geosmin, even at low levels, can be detected by the average person.
What is geosmin?
Geosmin is a naturally occurring compound produced by bacteria in soil and algae blooms found in surface water. Cold temperatures kill off algae in surface water, and the dead algae release the geosmin. Geosmin levels also increase during high algae blooms which occur during early Spring or when water temperatures start to rise, creating favorable conditions for algae growth.
Where is the odor and taste occurring?
There are reports of an earthy, musty-type odor/taste in the water coming from a variety of areas served by the Lake Palestine and Neches River water supply. Many water systems across Texas, including Arlington, Fort Worth, Houston, and other systems that use the Neches River, have experienced the same reports of the odor and taste.
Is the water quality affected?
While the taste and odor can be unpleasant, geosmin is not toxic or harmful. The water remains safe to drink. On-going testing continues to show an absence of harmful bacteria and other pathogens in the water. These standards are within requirements set by the Texas Commission on Environmental Quality.
How long will the taste and odor last?
It is impossible to predict the onset of an incidence of geosmin, or how long it will last. Geosmin compounds remain in waterways throughout the year at varying levels. The City of Palestine, through regional partners, regularly tests the water supply sources for various water quality parameters. Since the city started receiving complaints, the geosmin level in the Neches River and Lake Palestine has risen from 544 nanograms per liter (or parts per trillion) to 604 nanograms per liter.
To put this in context, the general threshold for human detection is about 15 nanograms per liter; however, people with sensitive pallets can detect geosmin in drinking water at concentrations as low as 5 nanograms per liter. This is why some customers notice the taste and odor stronger than others.
What does it smell like?
Geosmin typically produces an earthy or musty odor as is found in the odor of overturned rich soils, and is present in some foods such as beets, spinach, and mushrooms.
Why do we smell it?
The human nose is extremely sensitive to geosmin. If you poured a teaspoon of geosmin into the equivalent of 200 Olympic-sized swimming pools, you would still be able to smell it. The general threshold for human detection is about 15 ng/l (15 nanograms per liter = 15 parts per trillion). However people with sensitive pallets can detect these compounds in drinking water when the concentration is as low as 5 ng/l. Heating the water increases the volatility of these compounds, which explains why the smell is more easily detected when you are in the shower or when used for hot beverages.
Can the taste and odor be reduced at the tap?
To make the water taste better, try chilling it, adding ice cubes, a slice of lemon, or a few drops of lemon juice.
Can it be removed from the drinking water?
Geosmin cannot be removed by conventional water treatment processes, but with strategic actions taken during the treatment process and flushing of water supply lines, it can be reduced to a more acceptable level.
Does geosmin occur elsewhere?
Geosmin is common in many jurisdictions across the United States, Canada and elsewhere in the world.