Good News for the Metals Industry Regarding Proposed Metal Products and Machinery (MP&M) Regulations

Good News for the Metals Industry Regarding Proposed Metal Products and Machinery (MP&M) Regulations

Major revisions have been made to proposed regulations that would have required potentially extensive (and expensive) upgrades to wastewater treatment facilities at some metal working facilities.

The MP&M point source category includes facilities that manufacture, rebuild or maintain metal products, parts or machines. On May 30, 1995 the Environmental Protection Agency (EPA) published the initial set of proposed regulations. On October 31, 2000 EPA signed revised regulations. The revised regulations included effluent limitations that would replace existing limitations for Electroplating (40 CFR 413) and Metal Finishing (40 CFR 433) discharge categories. Some processes covered under the Iron and Steel Category (40 CFR 420) were also to be covered.

EPA received comments and published a new proposal on January 3, 2001. These regulations included new effluent limitations and treatment standards for direct dischargers (to a watercourse or waterbody) in eight MP&M categories and new pretreatment standards for indirect dischargers (to a sanitary sewer or POTW) in three categories. On June 5, 2002 EPA published a Notice of Data Availability (NODA) that included a discussion of major issues raised by commenters on the 2001 proposal, and preliminary revised effluent limitations and pretreatment standards. EPA received over 300 comment letters on the NODA.

Amid widespread protest from regulated industrial sectors, EPA collected additional data and significantly scaled back the proposed regulations. After consideration of comments and review of the technical and economic data used to develop the proposed regulations, the EPA has determined that final regulations should be issued only for the Oily Wastes category. Treatment standards are proposed for direct dischargers, however no pretreatment standards are established for indirect dischargers.

The new regulation applies to oily operations including abrasive blasting; adhesive bonding; alkaline cleaning for oil removal; alkaline treatment without cyanide; aqueous degreasing; assembly/disassembly; burnishing; calibration; corrosion preventive coating; electrical discharge machining; floor cleaning in process areas; grinding; heat treating; impact deformation; iron phosphate conversion coating; machining; spray or brush painting including water curtains; polishing; pressure deformation; solvent degreasing; steam cleaning; non-destructive testing; thermal cutting; tumbling/barrel finishing; washing; welding; wet air pollution control for organic constituents; and suboperations. Process rinses that remove materials deposited by these operations are also covered by this regulation.

EPA will establish Best Practicable Control Technology pH limitations and maximum daily limitations for oil and grease as hexane extractable material and total suspended solids. Treatment measures that will be required include in-process flow control and pollution prevention and chemical emulsion breaking followed by oil separation.

EPA estimates that the approximately 2,400 direct dischargers subject to the proposed regulations are expected to make the necessary investments to meet the requirements and continue to operate under the proposed regulations. EPA estimates that no operating facilities will close or experience moderate financial impacts due to the proposed regulations.

EPA expects that benefits from the proposed regulations will include reduced cancer and non-cancer health risks, and reduced non-cancer adverse health effects, due to ingestion of chemically contaminated fish and unregulated pollutants in drinking water; enhanced water based recreation including fishing, boating and other activities; and reduced risk to aquatic life. EPA estimates that the final regulation will prevent the direct discharge of 18 pounds per year of carcinogens, 119 pounds per year of lead and an additional 6,900 pounds per year of 76 pollutants of concern that are known to cause adverse non-cancer human health effects.

The final rule was signed by the EPA on February 14, 2004 and EPA has submitted the rule for publication in the Federal Register. The final rule may be found on EPA’s website at

EPA originally proposed a 3-year compliance deadline from date of publication of the final rule for existing sources. Industries should review their discharges, and if necessary, develop a strategy for achieving compliance with the final regulations. Long term facility planning, including future expansion, should also include consideration of these regulations.