Data Hunt: Once a year, EPA auctions a certain number of 502 allowances at the end of March. Utilities, Environmental groups, allowance brokers, and anyone brokers, and anyone else interested in purchasing allowances can participate. Allowances sold at the auctions will be sold to the highest bidder until no allowances remain. Successful bidders are notied and are listed on the EPA's Web site.Go to the following site: h_ttps: www.ep_a.gov{airmarketsg2007-5023llowance-auction a.- How much was the highest bid for a 502 allowance? (ex: If the highest bid is $4,200.00, then enter 4200)