The NAM challenged the Environmental Protection Agency’s (EPA) 2013 final rule on commercial and industrial solid waste incineration (CISWI) units, which imposes stricter emissions limits on industrial, commercial and institutional boilers. The rule follows a 2011 rule that also imposed restrictions on materials used as fuels or ingredients in combustion units. The rules will impose additional costs and require sectors impacted by the rule to provide additional resources to remain compliant. The court consolidated this case into , a challenge to the 2011 rule on CISWI units, where the NAM argued that 1) the EPA failed to account for variability in waste materials when classifying best-performing units; 2) the EPA should consider emissions occurring during startups, shutdowns and malfunctions when determining whether emissions limits are achievable; and 3) the EPA could not impose recordkeeping requirements through the CISWI rule on operators that combust non-hazardous secondary materials that are not waste. Although the court rejected the NAM’s arguments, it ordered the agency to provide further justification for some of its conclusions.