| #Q001 | administrative | unknown | guidance | Coverage Definitions Reference | wastewater | For precise definitions of coverage, refer to the applicability sections in 40 CFR Part 418. | When determining precise definitions of applicability and coverage. | high |
| #Q002 | prohibition | treatment | mandatory | Zero Discharge Prohibition | wastewater | Some wastestreams have zero discharge requirements. | Varies by subcategory and specific wastestream. | medium |
| #Q003 | administrative | unknown | guidance | Current Regulatory Requirements Reference | wastewater | For the current regulatory requirements, refer to 40 CFR Part 418. | | high |
| #Q004 | prohibition | treatment | mandatory | Zero Discharge Requirement for Specific Segments | wastewater | For three of the process segments, the technology basis of the regulations is "no discharge of process wastewater pollutants." | Applies to three specific process segments within the Metal Molding and Casting regulation. | high |
| #Q005 | monitoring | reporting | mandatory | TTO Monitoring for Indirect Dischargers | wastewater | ...a bulk parameter (oil and grease) for monitoring total toxic organics (TTO) in all subcategories for indirect dischargers (see 40 CFR 464.03(a)). | Applies to indirect dischargers in all subcategories (Aluminum, Copper, Ferrous, and Zinc Casting). | high |
| #Q006 | administrative | operational | guidance | POTW Standards Selection | wastewater | For indirect dischargers, which is the larger number of plants, POTWs may elect to establish mass-based or concentration-based standards based on the limitations or standards established in the regulations. | Applies to POTWs regulating indirect dischargers. | high |
| #Q007 | operational | unknown | guidance | Applicability Overlap Review | wastewater | Special care needs to be given to potential for overlap of applicability to Metal Molding and Casting facilities with other categories, such as Metal Finishing (note particularly the presence or absence of six "core operations" that must be present for operations to be covered by the Metal Finishing regulations (40 CFR Part 433), Aluminum Forming (40 CFR Part 467), and Copper Forming (40 CFR Part 468). | When determining regulatory coverage for facilities that may involve multiple metal-related processes. | high |
| #Q008 | administrative | unknown | mandatory | Compliance with 40 CFR Part 464 | wastewater | The EPA promulgated the Metal Molding and Casting (MMC) Effluent Guidelines and Standards (40 CFR Part 464) in 1985. | | high |
| #Q009 | administrative | reporting | mandatory | NPDES Permit Incorporation | wastewater | The Effluent Guidelines are incorporated into NPDES permits for direct dischargers, and permits or other control mechanisms for indirect dischargers. | Applies to facilities discharging to surface waters or through POTWs. | high |
| #Q010 | administrative | reporting | mandatory | Regulatory Reference Compliance | wastewater | The EPA promulgated the Metal Molding and Casting (MMC) Effluent Guidelines and Standards (40 CFR Part 464) in 1985. | | high |
| #Q011 | administrative | operational | guidance | Development Document Review Guidance | wastewater | Please review the MMC Development Document regarding process operations and associated wastewaters covered in each subcategory (Sections 3 and 5) and the Appendices, notably Appendix C. | When determining process operations and associated wastewaters covered in each subcategory. | high |
| #Q012 | monitoring | reporting | mandatory | TTO Monitoring Specification | wastewater | Examples of the pollutants with effluent limits for Foundries are total suspended solids, phenols, copper, lead, and zinc, and also a bulk parameter (oil and grease) for monitoring total toxic organics (TTO) in all subcategories for indirect dischargers (see 40 CFR 464.03(a)). | Applies to indirect dischargers in all subcategories. | high |
| #Q013 | operational | treatment | mandatory | Oily Wastes Subcategory Applicability | wastewater | The MP&M effluent limitations apply only to facilities that directly discharge wastewater from oily operations in the Oily Wastes subcategory. | Applicable specifically to direct dischargers in the Oily Wastes subcategory. | high |
| #Q014 | administrative | unknown | mandatory | Performance Standards Sector Coverage | wastewater | In addition to some government facilities, the regulation sets performance standards for facilities in these industrial sectors: Aerospace, Aircraft, Bus and Truck, Electronic Equipment, Hardware, Household Equipment, Instruments, Mobile Industrial Equipment, Motor Vehicle, Office Machine, Ordnance, Precious Metals and Jewelry, Railroad, Ships and Boats, Stationary Industrial Equipment, Miscellaneous Metal Products. | Facilities that manufacture, rebuild, or maintain finished metal products, parts, or machines, and generate oily wastewater. | high |
| #Q015 | design | treatment | mandatory | BPT Technology Implementation | wastewater | The regulation sets daily maximum limits for two pollutants, oil and grease (as hexane extractable material) and total suspended solids, based on the best practicable control technology (BPT): 1. In-process flow control and pollution prevention 2. Oil-water separation by chemical emulsion breaking and skimming | Applies to facilities in the Oily Wastes subcategory. | high |
| #Q016 | administrative | reporting | mandatory | NPDES Permit Incorporation | wastewater | The MP&M regulation covers only direct dischargers and the requirements are incorporated into NPDES permits. | Applicable to direct dischargers that manufacture, rebuild, or maintain finished metal products, parts, or machines, and generate oily wastewater. | high |
| #Q017 | operational | operational | mandatory | Industrial Sector Performance Standards | wastewater | the regulation sets performance standards for facilities in these industrial sectors: Aerospace, Aircraft, Bus and Truck, Electronic Equipment, Hardware, Household Equipment, Instruments, Mobile Industrial Equipment, Motor Vehicle, Office Machine, Ordnance, Precious Metals and Jewelry, Railroad, Ships and Boats, Stationary Industrial Equipment, Miscellaneous Metal Products. | Includes federal, state, and local government facilities such as municipal maintenance facilities (bus/truck/snow removal) or military bases. | high |
| #Q018 | prohibition | operational | mandatory | Oily Wastes Direct Discharge Applicability | wastewater | The MP&M effluent limitations apply only to facilities that directly discharge wastewater from oily operations in the Oily Wastes subcategory. | Only applies to the direct discharge of wastewater from oily operations. | high |
| #Q019 | treatment | treatment | mandatory | BPT Technology Compliance Standards | wastewater | The regulation sets daily maximum limits for two pollutants, oil and grease (as hexane extractable material) and total suspended solids, based on the best practicable control technology (BPT): 1. In-process flow control and pollution prevention 2. Oil-water separation by chemical emulsion breaking and skimming | Direct dischargers in the Oily Wastes subcategory. | high |