DAG would like to see the required distances between wells and protected uses increased from 1,000 to 1,500 feet.
Why? Well, because 2,500 feet is probably not politically realistic. 1,500 feet is certainly achievable - Flower Mound already has this in their ordinance.
Ok, but why is it necessary to move wells back further from places where people live, work, and play?
We have been running a real-world experiment with shale gas development in urban areas (more generally, fracking close to people). We presumed this was largely non-problematic (thus very short minimal distances required in the early goings). We have been collecting data (though not nearly enough) to test that presumption. And it turns out that it looks like a bad assumption, so we need to adjust the distances upward.
What evidence is there for my claim? There is this FLIR video that shows VOCs belching from a pad site right next to a park. We did not know about this, because we have not been using the best technologies to monitor for pollutants. But now we have started using such technologies and I think the conclusion is that we would like parks, schools, and homes to be further away from this kind of pollution. Citizen-science has made the invisible visible - we can now see what has been hidden.
There is this 2012 study funded by the Colorado School of Public Health. It found: "Residents living less than .5 mile from wells are at greater risk for health effects from NGD than are residents living more than .5 mile from wells. Subchronic exposures to air pollutants during well completion activities present the greatest potential for health effects. The subchronic non-cancer hazard index (HI) of 5 for residents less than .5 mile from wells was driven primarily by exposure to trimethylbenzenes, xylenes, and aliphatic hydrocarbons. Chronic HIs were 1 and 0.4. for residents less than .5 mile and more than .5 mile, respectively. Cumulative cancer risks were 10 in a million and 6 in a million for residents living less than .5 mile and more than .5 mile from wells, respectively, with benzene as the major contributor to the risk."
I think we know enough now to warrant futher protections - further distances from pad sites.