Traffic enforcement officers pulled over a driver with a reading too high for the roadside RBT device in Roleystone.
A Holden Commodore was stopped at 10:50am on Croyden Road in Roleystone on Wednesday March 13.
The 51-year-old male driver from Kelmscott was barely conscious according to police, and his roadside test was too high for the machine.
Police say "it appeared he'd stocked the front seat of his party bus so he'd never run out."
Once back at the station his reading was 0.338% calculated to be 0.307 grams of alcohol per 100ml of litres of breath at the time of occurrence.
That is almost seven times the legal limit.
The man has been charged with driving a motor vehicle under the influence of alcohol.
He is due to face the Armadale Magistrates Court in June.
The front passenger seat of the man's vehicle. Picture: WA Police.
UPDATED: 11-year-old boy dies after push scooter crash in Mandurah
Cooloongup man accused of historical child sex offences dies just weeks before trial
Boat owners urged to make safety a priority this Easter
Mundijong man accused of attempting to procure children overseas for sexual activity
PM Anthony Albanese to address nation
Mandurah teacher who raped student to remain on bail
Man charged after allegedly exposing himself to girl on Transperth bus in Lakelands
Fire rips through Golden Bay home
Firefighters battle bushfire near Nambeelup