On August 2, 2013, EPA published a Notice of Data Availability regarding its proposed coal ash rule in the Federal Register. EPA is requesting comment on two aspects of the proposed rule: (1) the feasibility of complying with the Agency's proposed timeframes for closing surface impoundments under the Subtitle D option; and (2) the technical requirements (including the design and operating requirements for new Coal Combustion Residuals ("CCR")  landfills) for CCR overfill units that have been constructed on top of closed surface impoundments or landfills. EPA is also requesting comment on additional data that was provided as part of the proposed effluent guidelines rulemaking, including industry responses to a questionnaire regarding wastewater generation and treatment, which EPA may use to supplement its Regulatory Impact Analysis and risk assessment for the final rule. In addition, EPA is requesting comment on data concerning the use of coal ash in large-scale fill and certain surface impoundment structural integrity assessments.

Comments on the Notice of Data Availability are due on September 3, 2013. EPA has not indicated when it expects to issue a final coal ash disposal rule, but observers believe it will be issued after the related effluent limitations guidelines rule is finalized, which is expected in the first half of 2014.