BRIDPORT, Vt., Dec. 17 – From her bedroom window, Blue Collins can look across Lake Champlain to see the white cloud of emissions rising from the International Paper Co. mill in Ticonderoga, N.Y.

It is a sight that fills Collins with outrage, the same outrage that drove her 15 years ago to write 3,000 letters to corporate executives, warning them that their polluting ways could lead to random acts of violence and even assassinations.

Blue Collins was known as Sandra Good then. She was the roommate of Lynette Fromme, the woman who attempted to kill then-President Gerald Ford, and a member of the family of Charles Manson, the Rasputinlike figure who killed and masterminded the killing of nine people.

The FBI said the letters found in her apartment contained death threats. She says they were simply warnings.

“I never threatened anybody,” she said. “I was simply warning them of the potential consequences of their behavior. Anyone who would threaten to take care of the heads of all corporations would have to be a total nut.”

Whichever is true, she served 10 years of a 15-year sentence in federal prison for conspiring to mail the letters and for threatening the same people in a series of radio interviews.

In 1985, she settled in Vermont, dropping the name Good to shield herself from an aggressive press.

But now she has shed the cloak of anonymity she has worn for more than four years, wrapping herself instead in anger over the paper mill and its effect on Lake Champlain.

It is an anger that is so great that Collins and her housemate, Earl Parsons, refused the $12,000 they would have received when the company recently settled a suit with lakefront landowners on the Vermont side for $5 million.

In the settlement, which she protested in front of the federal courthouse in Burlington, the company admitted no wrongdoing in polluting the lake and is protected from any future legal action by landowners.

Her protest was photographed and led to the revelation of her former identity.

Until she took up the cause of the lake, Collins, a sandy-haired, wiry woman in her 40s, lived quietly, without a car or checking account, growing vegetables and flowers to sell locally.

In the winter, when the gardens had been harvested and the solar house was filled with drying flowers, she spent her time walking and thinking.

“I am amazed by the leap in environmental awareness I see around me,” said Collins, who is known to her friends as Blue, a nickname given her by Manson, who is serving a life sentence.

“I got locked up for saying these things. Fifteen years ago, people considered this fanaticism.”

It would seem that her zeal has not waned. She hitches rides to meetings of the newly formed Lake Champlain Steering Committee, authorized under a joint agreement among Vermont, New York and Quebec to clean up the lake.

At the moment, Collins has two important goals in her life. One is to save the earth.

The other is to be reunited with Charles Manson. In 1985, she had planned to settle near him in California until state authorities prevented it.

When her five-year probation ends in December 1990, she said, she plans to go to California, where he is serving his sentence.