The Department of the Environment amended Md. Code Regs. 26.09, Maryland Carbon Dioxide Budget Trading Program. Changes implement provisions of the Healthy Air Act, which required Maryland to join the Regional Greenhouse Gas Initiative, a 10-state market based carbon dioxide cap-and-trade program. In order to create additional incentives to generate electricity in non-carbon dioxide producing ways, the department is outlining eligibility requirements for the Voluntary Renewable Set-Aside Account, which encourages the voluntary purchase of electricity that has a demonstrated greenhouse gas benefit. The rule took effect May 16, 2011. http://www.dsd.state.md.us/mdregister/3810.pdf p. 617.