Thx Augie, I contacted two mud loggers from Oil & Gas services - around myarea the Utica Shale play is alive and being drilled.

We discussed the bentonite slurry in the middle and cement at both ends and one had actually fixed a pod 8 years ago with this method. While I agree that
"correlation does not equal causation"
the likelihood that both events "didn't happen interdependently over a 60 year period and then occurred together is compelling.

And as Augie pointed out, ponds connected via spoil banks (where they place overburden from a strip mine operation) - my Figure8 pond dropped the exact same amount as LP, (Google earth has the surface elevation exactly he same prior to the blow out) I expect Figure8 pond to rise to the level of the new overflow installed in LP.

If it works...