Ms Brockovich rose to prominence after championing successful legal battles against major corporations polluting the environment. A movie based on her legal battles starring Julia Roberts was released in 2000.
In an editorial for The Guardian, Ms Brockovich said she was frustrated with one of Mr Biden's picks for his EPA transition team, Michael McCabe.
She said Mr McCabe was a former employee of Mr Biden and deputy at the EPA before leaving to enter the private sector and work in communications for DuPont, a chemical company that has been criticised for its connection to chemicals that have led to birth defects and illnesses in those exposed to them.
Ms Brockovich specifically pointed to DuPont's fight against regulations on a chemical called perfluorooctanoic acid.
"The toxic manmade chemical is used in everything from waterproof clothes, stain-resistant textiles and food packaging to non-stick pans. The compound has been linked to lowered fertility, cancer and liver damage," she wrote.
She said she felt that Mr Biden was considering the same kinds of industry insiders who would be open to outside influence that Mr Trump selected for his administration.
"This smells of the dawn of the same old. To quote The Who: meet the new boss, same as the old boss," she wrote. "It should go without saying that someone who advised DuPont on how to avoid regulations is not someone we want advising this new administration."
She claimed that Mr McCabe's work for DuPont would have "inevitably contributed to staving off costly clean-up and additional regulation headaches for the company."
"Are we already falling back on the old and antiquated, hide-and-seek, conceal, dodge and deny leadership or are you going to come out and be the change and the hope needed when it comes to the environment?" she wrote.
She called on Mr Biden to "keep your promise" and to "give the people a voice and a seat at the table" to find solutions to environmental issues.
"We are in this mess because we continue to do the same old thing," she concluded.
Some liberals on Twitter were quick to chastise Ms Brockovich, complaining that she should not be criticising Mr Biden in the midst of the election challenge posed by Donald Trump.
"We want Erin B to be better, not so sure she can be. Better DuPont be with us than against us, that you don't get THIS is STUNNING!" one user wrote.
Another said she was comparing "apples to oranges" and suggested Mr Biden had to find someone in the "middle to guide."
Jordan Uhl, a progressive activist, pointed out the irony of critics telling Ms Brockovich to be happy to have chemical companies in league with the president-elect.
"How oblivious do you have to be to tell Erin Brockovich that the chemical companies are on 'our side?'" he wrote.
Ms Brockovich said her editorial was not about her politics.
"It's about politics as usual. We want, we need Joe Biden to better because he can be," she said.