NCS000330_Staff Report_20190710

NC Division of Energy, Mineral and Land Resources
Review for Permit — NCS000330
ATI Allvac — Monroe Plant
Facility Activities and Processes:
• SIC Code: 3341— Secondary smelting and refining of nonferrous metals.
• The facility is engaged in melting, casting, forging, rolling, sawing, and grinding of nickel and
titanium alloys. In addition, the plant also carries out "conversion" type processes (forging,
rolling, sawing, and grinding) of tools, steels, stainless steels, and various other alloys for outside
customers.
Monitoring Information:
Changes have been made to several monitoring parameters, including a change to two benchmarks.
Vehicle maintenance monitoring parameters have been revised as follows:
• Non -polar Oil and Grease [EPA Method 1664 (SGT-HEM)] replaces Oil and Grease/TPH. The
benchmark for Non -polar Oil and Grease using this method is 15 mg/L. This requirement
appears in all individual stormwater permits; however, it only applies to facilities that perform
onsite vehicle maintenance activities. If the facility begins vehicle maintenance during the
permit cycle, the requirements shall apply.
• pH monitoring is no longer required for discharges only associated with vehicle maintenance
activities.
No other monitoring parameters have been changed or added from the last permit term.