Erin Brockovich is an unemployed single mother with 3 kids and divorced from her 2 husbands. She is desperate to find a job, but is having no luck; this losing streak even extends to a failed lawsuit against a doctor in a car accident she was in. With no alternative, she successfully convinced her lawyer (Ed Masry) to give her a job in compensation for the loss. While no one takes her seriously, with her trashy clothes and earthy manners that soon changes when she was organizing some paper regarding real estate cases, a certain file that seem suspicious and begins to investigate to a real estate case involving the Pacific Gas & Electric Company. During Erin’s examination of the local water records and interview with residents ill from exposure to poisonous chromium confirm Erin's suspicions, what she discovers is that the company is trying quietly to buy land that was contaminated by hexavalent chromium, a deadly toxic waste that the company is improperly and illegally dumping and, in turn, poisoning the residents in the area. Both Ed and Erin must make great sacrifices in their lives, as the legal costs spread Ed very thin, and the round-the-clock work takes Erin out of touch with both her boyfriend and her kids. Erin's kids resent the lack of attention from her, and her attempts to explain the merits of what she is doing to her eldest son are futile but, one day her eldest son happens across one of the many documents pertaining to the PG&E case. He reads of a child his own age that is very ill, and knowing that Erin's work will help this child, asks her why the child's mother cannot provide the needed help. When Erin explains that it is because the child's mother is very ill, too, her son, for the first time, appreciates the nature and importance of Erin's work.

As she digs deeper, Erin finds herself leading point in a series of events that would