A319
Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument
Flight Crew Last 90 Days 111.97; Flight Crew Total 2016.77; Flight Crew Type 1231.82
Confusion; Situational Awareness
Deviation / Discrepancy - Procedural Hazardous Material Violation; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Provided Assistance; Flight Crew Returned To Gate; General Maintenance Action; General Work Refused
Human Factors
Flying flight ZZZ to ZZZ1. Departed gate and taxied halfway to runway and received a call from ZZZ Ground Control Stating '[Aircraft X; immediately contact your company'. The First Officer contacted Company and he was told 'You have lithium ion batteries in the cargo compartment and they have to be surrounded by 15 bags; the batteries were only surrounded by 14 bags you have to return to the gate and have the lithium ion batteries removed from the cargo compartment.  We return to the gate; shut down engines; and ground personnel removed a box which appeared to be light weight based on the ground personnel's effort to lift it. We then departed for ZZZ1 without said cargo on board. I have several questions reference this incident. The first; was it legal or proper for the cargo to be carried in the cargo compartment to begin with? I was under the understanding that lithium ion batteries are not allowed in the cargo compartment. Second; how were these lithium ion batteries packaged? Third; from my previous experience as a firefighter adding an additional bag surrounding the lithium ion batteries; if they did catch fire; would simply be more fuel for the fire. I am unable to find any information in the FOM relating to carrying lithium ion batteries as cargo.
A319 Captain reported notification during taxi to return to gate to correct Dangerous Goods cargo load configuration error.