Today, U.S. Sen. David Vitter (R-La.), top Republican on the Environment and Public Works Committee, sent a follow-up letter to Dr. H. Christopher Frey, Chair of the Clean Air Scientific Advisory Committee (CASAC) Ozone Review Panel (the Panel) of the U.S. Environmental Protection Agency (EPA). The Panel is currently finalizing its review of EPA's scientific and policy assessments and its recommendations that will be used in EPA's forthcoming rulemaking on lowering national ambient air quality standards (NAAQS) for ozone. In the letter, Vitter urges the Panel to consider four specific issues that were left unresolved during last week's teleconference meeting, reiterating the need for error corrections and analysis to be completed prior to moving forward.

"It's clear that EPA's rulemaking process lacks transparency, and it is unfortunate that when the CASAC Ozone Review Panel met last week, a lot of issues were unresolved," said Vitter. "The Panel needs to commit to analyzing these issues in detail before EPA moves forward with the ozone NAAQS rulemaking, which, when lowered, will majorly impact States by placing nearly the entire country in violation of the revised standard."

On May 19, 2014, Vitter urged Gina McCarthy, EPA Administrator, to update and correct known errors prior to CASAC's final meeting. EPA issued memoranda acknowledging the need for correcting and updating risk data errors in the scientific assessments used in the rulemaking process. Vitter said that updating and correcting these analyses were too important not to complete prior to CASAC finalizing their recommendations.

In a May 14, 2014, letter, Sens. Vitter, Jeff Sessions (R-Ala.), John Cornyn (R-Texas), Tim Scott (R-S.C.), and James Inhofe (R-Okla.), asked member states of the Association of Air Pollution Control Agencies (AAPCA) to comment on CASAC's role in EPA's forthcoming rulemaking on the ozone NAAQS. Click here to read more.

Last week, Vitter released the responses from AAPCA member states regarding the CASAC process, and whether there is sufficient transparency, incorporated into the EPA's forthcoming rulemaking on NAAQS for ozone. Click here to read more.

Click here to read today's letter.

-30-