At trial, Salt's accuser said she tried to leave the man's home after a discussion about their failed romance and he prevented her from going. The woman said Salt grabbed her neck and gave it "two sharp twists." She bit Salt's fingers and they both fell to the ground, the woman said.
As they wrestled, the woman said Salt pinned her leg against her chest and hit her repeatedly with a piece of pottery and a metal bar.
Salt, however, said he never hit the woman with a weapon. At trial, Salt's attorneys, Ed Brass and Kim Cordova, said Salt was acting in self defense. Cordova said Salt called the woman a name and she slapped him, and that Salt was trying to calm the woman when she bit him and they both fell.
The accuser said she suffered cuts and bruises. An emergency room doctor later put 65 staples in her head, she testified.
Salt's ex-girlfriend said Salt has never shown remorse.
"I really, really hoped he would have that today," she said.
Third District Judge William Barrett gave Salt credit for 25 days in jail. He must report by Nov. 13.
"I don't think you're a bad person, but you were convicted of aggravated assault," Barrett told Salt. "The jury spoke."
Salt was convicted earlier this year of third-degree felony aggravated assault for injuring the woman during the fight. Jurors dismissed a first-degree felony count of aggravated kidnapping, which would have carried a mandatory prison sentence, and a misdemeanor charge for allegedly preventing the woman from calling 911.
Salt had no prior criminal record, Salt Lake County prosecutor Michael Boehm said, asking for a six-month jail sentence rather than prison.
Salt's environmental efforts have focused on the Great Salt Lake, the Jordan River and other waterways.
"It's been devastating for me," Salt told the judge Monday. "I've been a pretty well known person in the community. This has basically devastated my whole position in the community. I've struggled with that."
Salt has also been in a trademark dispute with the environmental network started by Bobby Kennedy, the son of the late Sen. Robert F. Kennedy.
Shortly after Salt was charged in the domestic violence case, Kennedy's Waterkeeper Alliance, a network of 190 environmental groups, tried to stop Salt from calling himself the "Great Salt Lakekeeper." The group filed suit in 2010, saying he had violated quality standards for alliance members and that the alliance was trying to protect its brand. In the most recent court papers, both sides indicated they are exploring mediation.
As part of his sentence, Salt must also complete 75 hours of community service.