Algae Bloom

[DickR]

Back around 1974-75, when I was considering a property over on Lake Winnisquam, I obtained a copy of a lengthy study on the algae bloom that occurred most years in August. While the algae bloom was not considered a health problem, it was a big aesthetic issue, and it caused a great reduction in water clarity in areas. The algae was determined to be a direct result of excessive inflow of phosphorous.

The report tabulated all the water inflows and exits, plus in absolute terms the inflows of phosphorous. By far the greatest source of water inflow was the Winnipesaukee river, which was said to be large enough to fill Lake Winnisquam three times over in the course of a year. However, the total phosphorous that flow brought was only a percent or so of the total. The lion's share of the total phosphorous came from the secondary sewage treatment facility at Laconia (IIRC) and from the laundry facility at the state school up the shore.

The solution already was being implemented. I spoke with one of the state engineers at Concord during that winter, and at that time he said that the new facility would be online soon. The sewage and state school laundry outflow, plus various flows from the Meredith area, would be piped over to a treatment facility in Franklin. He thought there might be one more summer with an algae bloom over there, as kinks were ironed out, but that afterward the annual bloom ought to be no more. Perhaps someone can comment on how things turned out on Winnisquam.

If the bloom in Wolfeboro also is phosphorous-limited, this would be a sure sign that tougher regulations on phosphorous usage around the lake are appropriate. Looking the other way when your neighbor fertilizes his waterfront lawn or leaf blows stuff into the lake is no longer acceptable.