LAS VEGAS — Environmental activist and movie namesake Erin Brockovich will face a misdemeanor charge of operating a boat while intoxicated at Lake Mead, the district attorney in Las Vegas decided Tuesday.

Brockovich, 52, has an Oct. 7 court date in Henderson Justice Court stemming from her arrest Friday evening at a marina on the Colorado River reservoir behind Hoover Dam, said Tess Driver, an aide to Clark County District Attorney Steve Wolfson.

A Nevada state game warden reported that Brockovich appeared to argue on the 26-foot Cobra motor boat with her husband, Eric Ellis, and threw a cellphone into the water before having trouble mooring the vessel at the Las Vegas Boat Harbor.

The warden said he had to help Brockovich dock the boat, and said two breath tests measured her blood-alcohol level at twice the legal limit of 0.08 percent.

The criminal complaint refers to Brockovich by her full name, Erin Elizabeth Brockovich-Ellis.

She could face six months in jail, a $1,000 fine, up to 96 hours of community service and court-ordered alcohol and drug counseling if she is convicted of driving under the influence as a first offense in Nevada, Driver said.

Brockovich, who was freed on $1,000 bail late Friday at the Clark County jail, was driving home Tuesday to Agoura Hills, Calif., said her publicist, David Kass.

She didn't immediately comment about the district attorney's decision to go forward with charges.

In a statement issued Sunday, Brockovich apologized but insisted she hadn't operated the boat in open waters.

"At no time was the boat away from the dock and there was no public safety risk," Brockovich said. "That being said, I take drunk driving very seriously, this was clearly a big mistake, I know better and I am very sorry."

Brockovich's efforts to sue Pacific Gas & Electric for polluting the water supply of a small Southern California town became the subject of a 2000 movie that earned Julia Roberts an Academy Award for playing Brockovich.

Brockovich now heads a consulting firm and was featured in the 2011 documentary "Last Call at the Oasis," about the planet's dwindling and increasingly polluted water supply.