In September, six Northeast states (Maryland, Connecticut, Maine, Massachusetts, Rhode Island, and Vermont) held the first mandatory auction of rights for power plants to release carbon dioxide. More than $38.5 million was raised by the auction of 12.5 million tons of carbon dioxide allowances. This consortium plans five other auctions through the end of 2009. Under this system, states limit the emissions within their borders and each utility must acquire enough allowances to offset its emissions, either through the auction or by later buying them from winning bidders. States in the West and Midwest are considering similar regional efforts, while Congress debates national legislation.