On April 24, the Environmental Protection Agency (EPA) hosted a public hearing in Philadelphia on a gasoline sulfur content, or Tier 3, proposal. The rule would reduce the level of sulfur in gasoline from the current standard of 30 parts per million to 10 parts per million; it is anticipated to cost refiners $10 billion in up-front capital costs in addition to $2.4 billion annually in operating costs. The rule is anticipated to reduce vehicle emissions as a result of the lower sulfur content. Massachusetts Department of Environmental Protection Assistant Commissioner Nancy Seidman, testifying on behalf of the National Association of Clean Air Agencies, praised the rule.