The EPA is publishing a proposed rule addressing specific technical issues consistent with a settlement agreement to resolve three issues raised in litigation of the final Coal Combustion Residuals (CCR) Disposal Rule, published April 17, 2015. Issues covered by this proposal will include the height limitation of the vegetative slopes of dikes; the type and magnitude of non-groundwater releases that would require a facility to comply with some or all of the corrective action procedures set forth in the final CCR rule; and adding boron to the list of contaminants in appendix IV of the final CCR rule that trigger the corrective action requirements under the final rule.