Increase in severity of summer algal concentrations over the past 15 years, high enough to be considered a bloom
2001, 2004 and 2007 worst
Shift in community composition from brown and green algae toward a dominance of cyanobacteria (Anabaena and Microcystis)
Blooms triggered by one point source of phosphorus discharge 75 miles upriver of where they eventually reached
Primary growth starting in Dolby Pond impoundment, Millinocket
Scums formed on the edges of Dolby Pond
Cell counts have been as high as 100,000/ml
No detectable levels of Anatoxin-a
2004 Microcystin levels were .20µg/L - below World Health Organization (WHO) level for finished drinking water
In 2007, Katahdin Paper was issued a Notice of Violation from Maine Department of Environmental Protection (DEP) stating that “the Department believes the primary cause of these problems is excess phosphorus discharges.”
Under currently proposed state nutrient and environmental response criteria these conditions would be considered “Impaired: Indeterminate cause.”
Blooms originating in Dolby Pond impoundment will likely not be prevented under currently proposed nutrient and environmental response criteria. Site-specific criteria will be needed for the Penobscot River.
