Here is an update...

The saltwater disposal company nearly devoured by a giant sinkhole this week in Liberty County was injecting sometimes double the amount of
saltwater into the ground that its state permit allowed.
But officials with the Texas Railroad Commission, which regulates such permits, stressed Friday that the cause of the sinkhole in the small town of
Daisetta has not been determined.
"We have no proven link between Deloach and the sinkhole," commission spokeswoman Ramona Nye said.
Deloach Oil and Gas Wastewater Disposal Co. declined comment Friday on the commission's notice that the company had violated its permit by dumping
128,000 to 192,000 barrels a month down its disposal well. Its permit allowed 90,000.
The company injected about 800,000 barrels more than the 1 million barrels that the permit authorized in 2007, Nye said.
url=http://www.chron.com/disp/story.mpl/front/5769131.html]The link[/url]
Why follow the regulations when there is money to be made. May be this isn't the cause but it sure seems very likely.
I am always a bit concerned about injection wells and how they are managed as there are a few in my area.
Some one else has paid a price for energy companies make money. The Texas RailRoad Commission seem to keep a watchful eye but incidents like this make
me wonder just how well they are watching.