Two things have since dawned on me.
1) Lake Winnipesaukee has historically been fed by springs.
2) In the 1950s, lake water had been drawn for every summer camp use.
Filtered by osmosis or not, leaching fields concentrated ALL the "nutrients" found in lake water and sequestered the "nutrients" deep underground. (But filtered, nonetheless).
People on wells aren't drawing the lake's waters, so the "nutrients"
aren't being filtered-out at those locations. By the hundreds, gallons of spring water from distant springs is also brought for consumption--
again--not filtering the lake's waters to purify it--at least "temporarily".
Therefore, water from wells is "stealing" the pure water found in the springs--
which, in turn--had been purifying Lake Winnipesaukee's waters.
No doubt.
While my circulator may open the ice, it is on a thermostatic device. Without the circulator, the
mink here would have to move on. They might have to move anyway, as the mussels have disappeared
this year--displaced by some kind algae plant.
Lakes are "lost" due to "eutrophication". Lake Winnipesaukee is too deep to end this way--anytime soon.