HINKLEY, Calif. — At the end of "Erin Brockovich," a housewife sick from toxic chromium weeps with joy as she's handed her portion of a historic $333 million settlement between residents of this small desert town and the utility that poisoned their drinking water.

In real life, that woman is Roberta Walker. She still lives in Hinkley, using her share to buy a new home in what she thought would be a safe four-mile distance from the toxic plume of chromium.

Earlier this year, she and other residents learned that the pollution, which Pacific Gas & Electric was required to clean up, was once again moving and had seeped into their groundwater.

Now, Brockovich has returned to the town that made her famous and is once again rallying residents, sampling the water and at a water board meeting on Wednesday is expected to announce that the contamination may be worse than the utility says.

For Walker and others involved in the original case, these developments are like stepping back in time and are a haunting reminder that a landmark lawsuit and a blockbuster movie are no guarantee of safety.

"We didn't bring a giant to its knees, all we did was wake it up," Walker said. "This is not happening again — I can't believe it."

Walker was instrumental in developing the original case that was filed in 1993.

The Hinkley housewife and mother of two grew suspicious after PG&E repeatedly offered to buy her house and agreed to bring her so much bottled water that she filled her entire pool with it.

Walker brought documentation of cancer-causing chromium contamination in her groundwater to a law firm, which passed the file to Brockovich. The two eventually worked on the case together, becoming close friends in the process.

While many of the more than 600 original Hinkley litigants moved away from the town after the 1996 settlement, Walker stayed. She preferred the remote desert landscape to a city skyline.

Now, Walker and Brockovich are struggling to understand how this could be happening all over again.

"When I first met Roberta back in 1991 and 1992, she said PG&E is buying property, handing out bottled water and my horse just died," she said. "This year she called and said they're buying property, handing out bottled water and my horse just died.

"Eerie doesn't describe it," she said. "It was out of body — it was like the 20 years never happened."

In 2008, the plume of chromium began spreading. Despite efforts by PG&E to stem the problem, tests this year showed it was growing again. According the utility and water board, the plume is two miles long and a mile wide.

The reported chromium levels are low enough not to violate drinking water standards but residents remain concerned.

Since January, Brockovich has been testing the water with Bob Bowcock of Integrated Resource Management.

They have taken as many as 180 water samples. Bowcock, the former utility director for several Los Angeles suburbs, said the tests reveal that the contaminated area is twice as big as the utility's estimates.

Brockovich and Bowcock expect to share some of these details at the Lahontan Regional Water Quality Control Board meeting.

At the meeting, Hinkley residents will also get an update on PG&E's cleanup effort. Lauri Kemper, the board's assistant executive officer, said they have asked to see the data, lab results and sampling procedures.

"We are always open to look at folks' data," she said.

One troubling discovery, Bowcock said, is that there is contamination well beyond the original plume boundaries.

He has a theory: Decades earlier, when pumping at nearby farms caused some residents' well levels to fall, that water was unknowingly replaced with thousands of gallons of chromium laced water.

Bowcock also said they have found much higher pollution levels than expected. Some areas, he said, are showing levels that are 400 times higher than the recommended public health goal.

While the utility believes the contamination is affecting an estimated 100 households, he believes the number is closer to 250.

"I don't think PG&E ever had their arms around the problem entirely," said Bowcock, adding that he was stunned by the results.

PG&E said it has not seen Bowcock's water testing results but remained committed to working with the community and the water district. The utility has been sending residents bottled water and has expressed interest in potentially buying affected homes.

"Our concern first and foremost is for the community of Hinkley," PG&E spokesman Jeff Smith said.

Walker, whose real life has not turned out quite as triumphantly as the celluloid version that won Julia Roberts an Oscar, called the company's concern "laughable."

Her daughters were 7 and 8 when they got their settlement from PG&E in 1996. They both have fibromyalgia and have had hysterectomies. Walker and her husband also have various health problems and have both had tumors removed, she said.

The settlement money disappeared into lawyer's fees and bad investments.

"Their main concern is for the community of Hinkley?" Walker said. "It's not true. They're just saying what you want to hear."