Organic supermarket chain Whole Foods Market fired a green PR salvo with its announcement today that it will phase out disposable plastic grocery bags by Earth Day in April.

The other grocery monoliths like Safeway and Stop & Shop will likely feel some pressure to make a similar move as the green movement targets plastic.

Whole Foods’ co-president and COO A.C. Gallo noted local and federal governments are cracking down on plastic shopping bags because of the environmental toll. He estimates Whole Foods’ move will cut 100M plastic bags from use in its 270 stores between April 22 and the end of 2008.

The New York City Council recently passed a bill requiring city stores of more than 5K feet to have a plastic bag recycling program. The powerful American Chemistry Council, which reps plastic bag makers, hailed that decision and touts plastic bags as recyclable and environmentally sound. [Edelman works with the ACC’s Progressive Bag Affiliates unit.]

The decision to cut the bags is not a sure-fire PR hit for WF, however. The AP noted that 90 percent of grocery customers ask for plastic when they check out.