Disposal of sewage sludge in a municipal solid waste landfill unit, as defined in 40 CFR 258.2 , that complies with the requirements in 40 CFR part 258 constitutes compliance with section 405(d) of the CWA. Any person who prepares sewage sludge that is disposed in a municipal solid waste landfill unit shall ensure that the sewage sludge meets the requirements in 40 CFR part 258 concerning the quality of materials disposed in a municipal solid waste landfill unit.
40 C.F.R. §503.4