Probable Cause: Naturally occurring algae in reservoirs that produce compounds such as Geosmin and MIB. These tastes and odors are most likely to occur in the fall when the algae start to die off and they release the compounds.
Is the water safe? Yes. While Geosmin and MIB can be detected by humans at very low levels, they are not harmful and occur naturally in some vegetables.
What is the BOPU doing to prevent this taste/odor:
Staff prevent the conditions that create these taste/odors in the water in Cheyenne’s reservoirs by transferring colder water from reservoirs at higher elevations to local reservoirs.
Staff also monitor and control algae growth in Cheyenne’s reservoirs throughout the summer. Each week, staff visit reservoirs to monitor water quality and algae growth. If algae growth begins to bloom, staff can prune the bloom by using a peroxide based algaecide. The algaecide the BOPU uses works quickly and breaks down into byproducts (hydrogent peroxide and oxygen) that quickly dissipate from water.
During the fall, when the water is more likely to contain the taste/odor compounds, the water treatment plant adds an additional treatment step that uses activated carbon to remove taste/odor compounds from the water.