Cross-posted from the NRDC Switchboard blog.

NRDC has obtained a copy of amendments that Sen. George Voinovich (R-Ohio) appears poised to lodge next week in the Senate Environment Committee to wage a sweeping attack on the Clean Air Act on behalf of dirty power plants. The amendments repeal, delay, and significantly weaken clean air safeguards that reduce power plant emissions of nitrogen oxides and sulfur dioxide (pollutants that cause smog and soot), as well as toxic mercury, arsenic, lead, hydrogen cyanide, and other acid gases.

The Voinovich amendments represent a complete rewrite of bipartisan legislation to strengthen the Clean Air Act cosponsored by Sens. Thomas Carper (D-Del.) and Lamar Alexander (R-Tenn.). That bill, entitled the “Clean Air Act Amendments of 2010,” could be brought to a vote in the Senate Environment Committee next week.

Sen. Voinovich’s amendments not only would drastically weaken, delay, and repeal crucial clean air and public health protection programs that EPA is carrying out to clean up dirty power plants that burn coal, oil, and natural gas. Adoption of these irresponsible amendments also would cripple the Carper-Alexander legislation, and in fact represent several giant steps backwards from the existing, stronger Clean Air Act.

Sen. Voinovich’s amendments represent the most systematic attack on air pollution cleanup measures for dirty power plants since the Bush administration’s failed, destructive “Clear Skies” legislation, also sponsored by the senator.

Systematically weakening the Clean Air Act is what these amendments are all about. A 5-page justification document obtained by NRDC along with the amendments identifies 46 categories of changes that the amendments represent to the Carper-Alexander legislation along with a “description”/ justification for those changes by Voinovich’s office. None of those 46 changes improves the public health or air quality features of the Carper-Alexander bill, with all 46 plainly weakening the base bill and most weakening the current Clean Air Act.

Of those changes, eight are identified forthrightly as “safe harbors” for power plants from current Clean Air Act requirements, a deceptively benign label for the loopholes and exemptions that these eight changes represent.

NRDC has prepared a document comparing the key weakening features of the Voinovich amendments to the Carper-Alexander bill as it was originally introduced, along with brief explanations where some of the amendments weaken current law.

In the passages that follow, I group the Voinovich changes into three thematic categories for discussion purposes.