When was the last time you heard a group of people worrying that gas prices might fall too low?


  That was the situation at an Eagle Ford small business session in LaVernia, where bankers and other financial people said one of the major barriers to credit for long term investments in Eagle Ford boom towns, which is badly needed to build infrastructure ranging from new roads to apartments and homes, is a worry that oil prices will fall below the level that is needed for the shale fracking field to remain profitable.


  Dr. Thomas Tunstall, an economist from UTSA and one of the leading experts on the economics of shale fracking, says that point is probably about $70 a barrel, due to the higher fixed costs involved in fracking, and he says falling prices thanks to a new oil fiend has been a problem before.


  "The reason that oil prices dropped in the seventies to the eighties had a lot to do with the North Sea find, and they really put a lot of oil onto the market that wasn't anticipated," Tunstall said.  "That was one of the key reasons that oil prices dropped at that time."


  Many bankers said lenders are haunted by the specter of previous oil booms gone bust, largely because the fall of oil prices made production unprofitable.  When the prices rebound, the oil drilling equipment has moved on to other areas, leaving behind half finished projects and a lot of bad written-off debts on banks' balance sheets.


  The price of oil today is about $96 a barrel.


  Many of the participants in the Eagle Ford said the vigorous exploitation of the shale oil is ramping up faster than anybody expected, with a huge need for everything from qualified truck drivers to new barbecue joints.


  Tunstall agrees that the boom has expanded at a huge rate.


  "Clearly from 2011 to 2012, we did not expect the rapid ramp-up that we say, going from $25 billion in economic impact to $61 billion in one year," he said.  "Going from less than 15,000 jobs to 116,000 jobs being supported by the Eagle Ford."


  By way of comparison, that is more jobs in the Brush Country oil fields than the total employment base of the city of Waco.


  "We knew things were developing quickly, we just didn't expect the number to come in that strong," he said.  "Along the coast, there is now $100 billion in projects which are either underway or planned as a result of the Eagle Ford activity."


  And participants said another of the serious potential barriers to complete exploitation of shale oil fields may be disappearing.  That is the concern of environmentalists that shale fracking, which uses high pressure water mixed with sand to 'fracture' the shale to get at the rich oil and gas deposits locked inside, is damaging water supplies and depleting scarce water supplies.


  "Water quality is a key issue," Tunstall said.  "The companies are experimenting with what are called 'gas fracks,' using CO2 gas, propane fracks, even oil fracks, so they may be able to start pulling this oil and gas out of the ground without even using water."