If the Water Looks and Smells Bad, it May Be Toxic, UCGS Study

ScienceDaily (Sep. 13, 2010) — Earthy or musty odors, along with visual evidence of blue-green algae, also known as cyanobacteria, may serve as a warning that harmful cyanotoxins are present in lakes or reservoirs. In a newly published USGS study of cyanobacterial blooms in Midwest lakes, taste-and-odor compounds were found almost every time cyanotoxins were found, indicating odor may serve as a warning that harmful toxins are present.