FALLS CHURCH, Va. — The woman who helped free an entire community from a toxic dump, literally rewriting environmental laws in the process, was so shy at the start of the struggle she tried to hide behind a tree when neighbors called on her.

Lois Gibbs took to the stage that day 35 years ago, in the seemingly idyllic community of Love Canal, N.Y., and began to find her voice. Transforming herself from homemaker to hell-raiser, she helped convince then-President Jimmy Carter to come to town in 1980 and remove 900 families from a 21,000-ton toxic dump. Earlier that year, Gibbs and her neighbors held two Environmental Protection Agency officials captive in a ploy to get the president’s attention. It worked.

Long before Erin Brockovich became a movie, Gibbs helped secure an environmental victory of greater heft. Love Canal’s war against the toxins under its feet prompted the federal government to create the Superfund cleanup program and earned Gibbs the Goldman Environmental Prize.

Today she is still in the fight as executive director of the Center for Health, Environment & Justice, a nonprofit squired in a third-floor corner office in a nondescript building in Fairfax County, Va., a few miles from Washington, D.C. A tiny gray sign hangs outside the door, betraying no sense of the history inside.

BELLE ROSE, La. — Tim Brown eases his john boat from his back yard dock into his daily therapy: The Bayou Corne that courses through this patch of southern Louisiana like a lifeline. Brown powers past the Tupelo Gum, Cypress Moss and Swamp Maple trees that drape the bayou in a frame, and steers to the spot where he reels catfish and collects thoughts.

“If I had to actually leave this place and go back to a house on dry land, I’d probably be dead in two years,” says Brown, 65 and retiring next year. “I guess you can say it’s a totally different life out here.”

But now that life, for Brown and 350 other residents in a neighborhood with “Crawfish Crossing” signs and roads named Gumbo, Jambalaya and Crawfish Stew Street, has been shattered by discovery of a 14-acre sinkhole that fractured the community’s calm and may bury its dreams.

The sinkhole, triggered by a collapsed cavern operated by salt mining operator Texas Brine Company LLC, swallowed trees and fouled the air when it appeared August 3. Its discovery sent the Bayou Corne community here in Belle Rose into a state of emergency: Assumption Parish and Louisiana officials ordered a still-in-effect evacuation as state officials scrambled to unearth what happened.

“Initially the concern was, that first day, you have a sinkhole … and you don’t know what caused it. All you know is a 400-by-400 section of marshland just got converted to a muddy pit. Trees were sinking into it and not coming back. It was like quicksand,” said Patrick Courreges, a spokesman for the Louisiana Department of Natural Resources.

HINKLEY, Calif. – Ten days before Christmas 1965, Pacific Gas & Electric Co. station chief Richard Jacobs walked a half-block on a dusty road lined with scraggly creosote shrubs to check out a neighbor’s toilet.

Jacobs carried with him a secret, something he referred to as the “chromate problem.”

Starting in 1952, the power company began mixing a toxic form of chromium with water to prevent rust at a new pipeline pumping station in Hinkley, a remote desert community united by a single school and a general store. PG&E dumped the chromium-laced water into a pond.

Lately there had been reports of problems with the neighbors’ wells. PG&E had just drawn greenish water from one well and discovered high levels of chromium. Now, retired farmer John Speth was complaining of greenish deposits in his toilet bowl.

Jacobs took a look in the bowl but assured Speth that PG&E had nothing to do with it. “When I left Mr. Speth,” Jacobs later wrote in longhand, “he was satisfied but still concerned about his water.” Speth died of stomach cancer in 1974.

It wasn’t until Dec. 7, 1987 — 22 years after that visit to Speth’s house — that PG&E finally told the local water board that it had contaminated the underground water. The company claimed it had discovered the problem just one week earlier.

From here, the story is familiar to anyone who saw the hit film Erin Brockovich. The corporate polluter was taken to court. The victims got millions of dollars. Problem solved.

In September 2010, scientists at the Environmental Protection Agency came to a startling conclusion: Even a small amount of a chemical compound commonly found in tap water may cause cancer.

The compound, hexavalent chromium, gained infamy in the Oscar-winning film Erin Brockovich, based on the David-vs.-Goliath legal duel between desert dwellers in Hinkley, Calif., and Pacific Gas & Electric Co. The film ends in Hollywood fashion, with the corporate polluter paying $333 million to people suffering from illnesses.

But in real life, the drama continues. More than 70 million Americans drink traces of chromium every day, according to the Environmental Working Group, a nonprofit research organization.

And now, more than a decade after the film, EPA scientists cite “clear evidence” that the chemical compound, also known as chromium (VI), can cause cancer. The federal agency was poised to announce its findings in 2011, a step almost certain to trigger stricter drinking-water standards to prevent new cancers and deaths.

The chemical industry’s trade association and chief lobbyist, the American Chemistry Council, urged the EPA to wait for more research, a common practice to delay action on toxic chemicals. However, Vincent Cogliano, the soft-spoken head of EPA’s chemical-assessment program, rebuffed the powerful group, writing in an April 2011 letter that “strong” new research was already available.

In 2007, when Deborah Rice was appointed chair of an Environmental Protection Agency panel assessing the safety levels of flame retardants, she arrived as a respected Maine toxicologist with no ties to industry.

Yet the EPA removed Rice from the panel after an intense push by the American Chemistry Council (ACC), an industry lobbying group that accused her of bias. Her supposed conflict of interest? She had publicly raised questions about the safety of a flame retardant under EPA review.

Rice’s travails through the EPA’s Integrated Risk Information System, or IRIS, program reveal the flip side of industry’s sway. Not only does the ACC back many scientists named to IRIS panels, it also has the power to help remove ones it doesn’t favor.

The ruckus over the Maine scientist surfaced six years ago, but its lesson echoes today.

To Rice, her removal points up an irony borne out by a Center for Public Integrity investigation: Scientists with deep ties to industry are allowed to continue on IRIS panels. But she — with no financial link to industry — was booted.

“It wasn’t like I was a consultant, saying this stuff is really bad because someone is paying me to do it. I was the toxicologist working for the state of Maine asked by my department to do these reviews,” she said. “That was the basis on which they said I was in conflict.”

Another irony: Rice’s assessment was on target. Two years later, the EPA moved to cease production of decaBDE, a chemical it views as a possible carcinogen. In Maine, Rice’s research had supported a state ban on the chemical.

The Environmental Protection Agency’s inspector general has begun a review of the EPA’s use of internal watch lists to target enforcement of federal pollution laws. The watch lists first came to light as part of a 2011 investigation by The Center for Public Integrity and NPR.

The inspector general is exploring “potential improvements in the protection of human health and the environment by ensuring the EPA is enforcing environmental laws and cleaning up communities,” the IG’s office wrote last month to Cynthia Giles, the EPA’s assistant administrator for the Office of Enforcement and Compliance Assurance.

The watch lists include allegedly chronic violators of the Clean Air Act, the Clean Water Act and the Resource Conservation and Recovery Act, which governs the handling of hazardous waste.

The EPA began to post the previously secret lists online in the fall of 2011 in response to a Freedom of Information Act request filed by the Center as part of the “Poisoned Places” investigation.

The project revealed that – two decades after Congress sought to crack down on chemicals that can cause cancer, brain damage and other ailments – toxic air pollutants continued to plague parts of the United States. The reports found that there were some 1,600 “high priority violators” of the Clean Air Act – nearly 400 of which were on the EPA’s watch list – and that federal and state regulators sometimes had trouble keeping tabs on oil refineries, power plants, steel mills and other industrial facilities that showered communities with contaminants.

DETROIT — In an economically distressed pocket of southwest Detroit known by its ZIP code — 48217 — the weekend of September 7-9 was one of the worst, pollution-wise, residents like Theresa Shaw could remember.

“I started smelling it on Thursday,” said Shaw, who immediately suspected the Marathon Petroleum Co. refinery a half-mile from her house. “I kept the windows closed because I couldn’t breathe. On Friday, I thought, ‘What the heck are they doing?’ My eyes were just burning, my throat was hurting, my stomach was hurting. I was having migraine headaches.

“The smell, it was like this burning tar, with that benzene and that sulfur. I wanted to scream.”

Shaw retreated to her sister’s house on the north side of town. Responding to citizen complaints, the Michigan Department of Environmental Quality traced the powerful odor to Marathon, which had been cleaning several large vessels, and wrote up the company for a nuisance violation.

Marathon says it is “committed to environmental responsibility” and acted quickly to correct the odor problem, a byproduct of plant maintenance.

Yet the episode further eroded residents’ trust in the company and underscored their fears about a $2.2 billion refinery expansion that will allow Marathon to process more high-sulfur Canadian crude oil.

The build-out, nearly complete, won’t add to the air pollution burden, Marathon promises. In fact, the Ohio-based company vows, emissions of some pollutants will go down and job numbers will go up.

Shaw doesn’t buy it. “They’ve disrespected us in this neighborhood over and over and over again,” she said.