Erin Brockovich would be the first to acknowledge that her new book, "Superman's Not Coming: Our National Water Crisis and What We the People Can Do About It" (Pantheon, $28.95), isn't light reading. And not just because the chemistry involved goes well beyond H2O.

"You have to, like, read a chapter and digest it, because it's overwhelming on top of everything else that is going on in this country," said the environmental activist and legal consultant in a recent phone interview from her California home. "But we have to address it. ... There is no Superman. Nobody's coming to save us, but we can save ourselves."

Brockovich, 60, became a household name 20 years ago when Julia Roberts played her in "Erin Brockovich." She's still inspiring scriptwriters. "Rebel," an ABC pilot in which Sons of Anarchy's Katey Sagal plays "a blue-collar legal advocate without a law degree" who's loosely based on Brockovich, is reportedly one of the first pilots the network plans to film once it's safe to do so.

"Superman's Not Coming" tells the kind of stories that don't fit neatly into a two-hour movie or a weekly TV drama. Anecdotes about grassroots action where defeats sometimes snatched from the jaws of victory are punctuated with a few stories of genuine progress. The fight for safe drinking water continues on many fronts.

A call to action that's likely to have readers checking their own water reports, the book's also a guide to the labyrinthine world of environmental politics, where meeting government standards, Brockovich contends, is no guarantee of safety. Neither, perhaps, is "winning."

"Superman" also follows up on what's happened to the town of Hinkley, California — the town at the heart of the 2000 film that won Roberts an Oscar — whose residents fought to get Pacific Gas and Electric to pay for contaminating their water. In the nearly 25 years since the record-setting $333 million settlement with Hinkley residents that was the film's climax, the underground "plume" that carries the carcinogen hexavalent chromium (also known as chromium-6) has continued to spread.

Q: I think the biggest surprise in this book for those who only know you as the person from the movie, is that the happy ending wasn't the end of Hinkley's problems. What's the situation there now?

A: It's gone. Roberta Walker, who was the original woman who rose up on this issue out in Hinkley, had moved several miles (away from the original area of contamination). And she called me one day and (someone from) Hinkley had been at her door and tested her well and she had hexavalent chromium in it. So at that point, we realized that plume was on the move again, and lawsuits started. PG&E got ahead of it a little and started just buying everybody out. That chrome plume still exists out there. That's going to take 200 years to clean up.

Q: We're dealing with a health threat, COVID-19, in which it's become important to trust science. You suggest some science, including work funded by the industries whose products are being studied, can't be trusted. So who are people supposed to trust when it comes to the safety of their water?

A: I think they need to trust themselves. Listen, we need science. But what most people don't understand is that EPA (Environmental Protection Agency) doesn't do studies on a chemical before it goes into the marketplace. It goes into the marketplace first. And then they have to commission a study. And it can take science eight, 10, 12 years to conclude what this chemical can do in the environment or to people. And then suddenly you get a notice like on PFOA, the perfluorooctanoic acid, which is our largest emerging contaminant in the water today. "Oh, Houston, we have a problem."

(PFOAs are among the chemicals classified as PFAS — per- and polyfluoroalkyl substances — and they've been linked to cancer, fertility problems, liver damage, high cholesterol, and other health problems. It's PFAS contamination from firefighting foam used on the Naval Air Station and Horsham Air Guard Station in Willow Grove and former Naval Air Warfare Center in Warminster that's at the heart of the concern over the water supplies of many residents of Bucks and Montgomery Counties.)

Even with the FDA (Food and Drug Administration), when you're dealing with products in the marketplace, medical devices, you've got to clear some five- and six-year studies before they even give approval to put them out into the marketplace. I think we need to start looking at how we handle chemicals and get the studies we need up front.

I had a conversation with a scientist, and we were in Columbia, Missouri; it was a radio show, talking about chloramines (disinfectants used to treat drinking water that are commonly formed by adding ammonia to chlorine). And he said, "You know, you don't have all the data to show that chloramines, in fact, are causing these health issues."

I said, "You're right. I don't. But here's the other side of that scientific conversation. You don't have all the data either to conclude that it doesn't."

Q: What's it like to have people think of you and automatically imagine Julia Roberts?

A: I hope they don't just see Julia Roberts. Julia Roberts is great. I'm so honored. But what I really want people to see is that you're that person, too. And that none of us can do it alone.