The impact was so powerful, it knocked down a power pole.
The crash interrupted power to more than 300 homes.
Quach did not attend Wednesday's hearing, but his attorney entered the guilty plea on his behalf.
Quach pleaded guilty to one misdemeanor count each of driving under the influence and driving with a blood-alcohol level higher than .08.
There was a sentence enhancement because Quach was driving with a blood-alcohol level higher than .20.
Following the accident, police said Quach's alcohol-level was .26 percent, more than three times the legal limit.
Orange County Superior Court Judge Thomas Rees sentenced Quach to the probation and ordered him to do 10 days with a Caltrans work crew and pay $2,000 in fines.
The District Attorney's Office says Quach was also ordered to take a nine-month-long alcohol awareness program.
Shortly after his arrest, Quach apologized to his constituents at a city council meeting.
Quach was elected seven years ago to the Westminster City Council.
Following the incident, some residents called for him to step down or be recalled.
And Quach was criticized for calling Assemblyman Van Tran (R-Garden Grove) to the scene. Tran arrived at the crash and identified himself as Quach's attorney, according to Westminster Police.
Officers said Tran had to be warned twice to step back or that he would be arrested if he continued to interfere.
Police say Tran was disruptive at the scene, although he did not interfere with the investigation.
Quach and Tran are two of Orange County's most prominent Vietnamese American elected officials.
Quach has said this is a personal matter and should not affect his elected position.