This case arises from violations of the Clean Air Act and its implementing regulations by the Defendant at the Allied Waste Niagara Falls Landfill, located at 5600 Niagara Falls Blvd. in Niagara Falls, New York. EPA issued a CAA Section 114 Information Request in 2011 and a supplemental Section 114 request in 2015. EPA also conducted an inspection of the Landfill in 2014. In anticipation of a potential joint enforcement action, EPA has entered into a Joint Prosecution and Confidentiality Agreement with New York State Department of Environmental Conservation (NYSDEC) relating to the Defendant. The violations involve the Defendant's ongoing failure to comply with (i) the municipal solid waste (MSW) landfill new source performance standards (NSPS), promulgated pursuant to Section 111 of the Act; and (ii) the maximum achievable control technology standards (MACT) for hazardous air pollutants at MSW landfills regulations, promulgated pursuant to Section 112 of the Act. Specifically, the Defendants violated: (1)Standards of Performance for New Stationary Sources General Provisions, 40 C.F.R. Part 60, Subpart A (NSPS General Provisions); (2) Standards of Performance for MSW Landfills, 40 C.F.R. Part 60, Subpart WWW (Landfill NSPS); (3) National Emission Standards for Hazardous Air Pollutants General Provisions, 40 C.F.R. Part 63, Subpart A (NESHAP General Provisions); and (4) National Emission Standards for Hazardous Air Pollutants: MSW Landfills, 40 C.F.R. Part 63, Subpart A