Bay City water tainted by blue-green algae

A larger than usual bloom of blue-green algae in Saginaw Bay is causing an unpleasant flavor in Bay City’s municipal water and adding to pressure to find a new source for water.

According to the Bay City Times most of Bay County gets water from the Bay City system, which draws from an intake near the mouth of the Saginaw River.

Blue-green algae is nothing new to the Saginaw Bay, but extremely high temperatures recently have brought more of the bacteria than normal. While treating the drinking water removes the algae, it releases a compound, when broken down, that leaves that dirty taste in the water.

Levengood said plant workers have put an oxidizer into the water treatment and amped up the amount of ozone — an oxidant known to treat the algae compound.

“It’s not going to hurt you, but it’s not something we want to taste in the water,” Levengood said of the algae.

Treatment is necessary because blue-green algae, a cyanobacteria, produces the toxin Microcystis.

According to Michigan Sea Grant:

Blooms of Microcystis are suspended in surface water and can give water a green appearance. These harmful algal blooms tend to stay in the water column, and the toxins can affect the liver, skin, or nervous system of humans who come into contact with them.

Bay City’s water system is also vulnerable to toxins from the Saginaw River which is known to be a source of dioxin and other chemical pollution.

In 2004 the Michigan Dept. of Environmental Quality measured dioxin at 26 pert per trillion in the sediments at the Bay City water intake and there are concerns that ongoing dredging will increase dioxin levels in the bay.

Also, the enormous coal ash piles at Consumers Energy’s Karn/Weadock power plant near the mouth of the Saginaw River are known to have leached arsenic into the bay.