The senators who signed the March 27 letter are James Jeffords, independent from Vermont and ranking member of the Senate Environment Committee; Frank R. Lautenberg, D-N.J.; and Olympia Snowe, R-Maine. In the letter, they express concern that the changes would provide residents with with less information about releases of toxic chemicals near their homes.

The TRI program, which went into effect in 1988, requires companies generating hazardous waste to report annually the volume of toxic material released. However, the EPA is proposing to reduce the regulatory burden on businesses by cutting the reporting frequency to once every two years. In addition, the proposals would reduce the reporting requirements for companies generating less than 5,000 pounds of toxic chemicals per year.

"The TRI program was established on a principle that the public has a right to know about chemicals that are being stored and released in their communities," Lautenberg said. "The agency´s proposal would curtail that right, leaving families uninformed. This is wrong."

Snowe said it didn´t make sense for the EPA to alter the TRI program before having a complete understanding of its impact on communities across the country.

"We know that more information leads to better decision-making," Jeffords said.

Other groups also have expressed concern about the proposed changes. Attorneys general from a dozen states have written to federal environmental officials asking them to reconsider reforming the TRI program.

But the plan also has its supporters, including the National Association of Manufacturers. NAM President John Engler has said the proposed reforms would reduce environmental regulatory burdens on small manufacturers while continuing to protect the environment.