I don't know if that's true, but if it is, it's the stupidest waste of tax money ever. There is NO way that a salt water disposal well could possibly cause an earthquake.
You can't even come up with a theory that was anything more than asinine.
That injection of liquids into wells can cause small earthquakes is well-studied and accepted in the scientific community.
http://www.nyx.net/~dcypser/induceq/iis.html
Over 100 scientific papers regarding injection-induced earthquakes - the most famous incidence of which was the waste injection at Rocky Mountain Arsenal in Colorado causing earthquakes in the 1960s.
"During the past several years, salt water injection in Paradox Valley has triggered earthquakes, and a reduction in well pressure has diminished the size of the earthquakes."
http://geosurvey.state.co.us/Default.aspx?tabid=330
See also Monson v. State, 673 P.2d 839 (OK 1983) for some litigation on the subject. http://www.oscn.net/applications/oscn/DeliverDocument.asp?CiteID=9570