Technology's unintended consequences. The second-most-painful financial debacle of my life involved a septic system at a rental property we owned from the mid- to the late 1990s. The town of Topsfield ordered us to replace the system after it failed in the midst of a massive flood in late 1996. Rather than fight, we decided to sell the property. It cost us about $50,000 -- $10,000 in engineering fees and $40,000 for the actual system.

(Our most-painful debacle began the day that Bill Clinton and Tony Blair talked down genomics stocks, a debacle that continues.)

So I was riveted this morning by Scott Kirsner's piece in the Globe on nascent sewage-cleaning technology that could greatly reduce the size of leaching fields, replacing much of a septic system with a unit that is about half the size of a water-heater. Even more important, it could bring the cost down to somewhere in the $2000-to-$10,000 range. It's about time.

Unfortunately, though Kirsner doesn't mention it, if this technology -- being developed by a Nashua company called Ovation Products -- works, there will be an enormous unintended consequence: vast pieces of property that are currently considered unbuildable will get a second look. And efforts to control sprawl will be dealt a huge blow.