Why does NASA have to list its own sources?  So if the level of airborne benzene in Porter Ranch got as high as 3.9 ppb would you say that the level of airborne benzene measured after the Encana Coslette B spill east of Erie, CO in June, 2015 of 1,000 ppb should have been enough airborne benzene to at-least let the public know that they were driving within 400 feet of the source?

Furthermore, Metro-Denver's northern suburbs were sitting on top of a nearly abandoned oil field when suddenly new technology came along that threatens to destroy the health and safety of a 6-figure number of residents.  In-response the Martinez decision has found that COGCCs interpretation of State oil & gas law is wrong, and that resident health and safety must come first over oil industry profit.  

If resident health & safety must come first, what is the safe drilling setback if multiple peer-reviewed medical journal studies have found that oil & gas increases asthma attacks by up to 400% within 12 miles?