Okay, but here's what I don't understand:
1) We've had heavy rains for many years
2) We've had periods of high surf for many years
3) We've had these same septic systems for many years
4) We've head heavy tourist traffic in summer for many years
But, this is the first year we've had poor water quality ratings.
What's the difference? Are all the septic systems breaking down suddenly? It seems logical that septic systems near the beach would be bad, but is that really the cause? Right now that's just a bunch of message board speculation. Doesn't the health department monitor septic systems?
It's been suggested that overuse of these septic systems (by tourists) may be a cause. But if I had a rental house with a septic system, wouldn't the users see some indications of breakdown? I mean things like backed up sewer lines, sewage backing up into toilets and bathtubs, and pooling in the yard, which are things I don't think most renters would find attractive.