Elsewhere on this site you will find references to the public health, environmental and agricultural implications of shale gas fracking.
One of the three licenced Companies, Tamboran Resources, has stated that they will not use chemicals in their fracking fluid. Tamboran further stated that succeeding companies will not be bound by this promise.
However, even if no chemicals were to be introduced, the fracking process produces flowback fluid, and these have the potential to include pre-existing underground compounds such as radium, radon, brine (toxic to animals), benzene etc. (see Dr. Law’s letter to Minister Foster on this site – Public Health Correspondence tab, top of page, for fuller information). This fluid can contaminate water supplies, and in storage and transport can be subject to surface spillages.
The methane gas itself, which is water-soluble, can migrate to affect water supplies.
The integrity of wellbore casings, upon which much of the promised safety depends, is dealt with in Dr. Ingraffea’s letter on this site (Public Health Correspondence).
Additional note: The minor earthquake near Blackpool in Lancashire, caused by fracking, resulted in a cracked wellbore casing in one of the two wells.