Document ID: EPA-HQ-OAR-2017-0685-0041
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2019-06-04T04:00Z

MEMORANDUM
Date:		April 10, 2018
To: 		Rulemaking Docket for the Surface Coating of Metal Coil RTR
From:		Paula Hirtz, OAQPS/SPPD/MMG
Subject:	Site Visit Report for Precoat Metals, Columbia, South Carolina
In support of the risk and technology review (RTR) for the Surface Coating of Metal Coil NESHAP (40 CFR Part 63 subpart SSSS, U.S. Environmental Protection Agency (EPA) staff Keith Barnett and Paula Hirtz conducted a site visit to the Precoat Metals facility located at 650 Rosewood Drive, Columbia, SC on April 5, 2018. The Precoat facility is a major source of HAP and is therefore subject to the NESHAP. EPA met with the Director of Environmental, Health and Safety (EHS) for Precoat Metals, Anu Singh, and the Precoat Metals Columbia SC facility EHS Manager, Rob Kincaid, to discuss the topics of interest identified by EPA in a site visit letter and to tour the coil coating operations. Discussion of these topics are included below.
General Information
The Precoat Metals Columbia SC facility operates 12 hours a day.
The line speed at this facility is 500 ft/min (the Precoat St. Louis plants run slightly higher at 700 ft/min).
About 16% of production at this location is building products, garage doors, siding, roofing, silos, ductwork, large appliances, and they can print brick, camo, wood grain onto finished metal product.
The facility coats coils of aluminum, steel, and stainless steel. 
Precoat owns and operates 14 facilities. 
Twelve Precoat facilities have one coating line and two facilities have two coating lines.
The same prime coat is used by all Precoat facilities. 
The finish coat varies from facility to facility and it also varies from one side of the coil to the other (both sides of coil are coated).

Technology Review
Over time the facility has changed its practice to use more compliant coatings but not enough to operate without the add-on controls.
All emissions from the prime and finish coat are captured in the permanent total enclosures (PTE) and routed to the RTO. 
The coatings are prepared in the PTE, which is designated as a Class 1 fire prevention area.
Fifty-five gallon drums of paint are mixed in the PTE. The paint is pumped from open drums to the application tray. Each drum lasts about 30 minutes.

Emissions of Hexavalent Chromium 
After cleaning the metal coil, it goes through a double pretreatment process; a wet process followed by a dry process known as a Chem Coater.
The wet process is a dip tank of Ni/Cr/Zn or Ni/Zn/Phosphate (bonderite) followed by chromic acid that is roll applied (dry process).
After the wastewater precipitant from the dip tank is stabilized with lime, a toxicity characteristic leaching procedure (TCLP) analysis is conducted in accordance with RCRA for hazardous waste disposal, which results in a determination of the trichrome concentration, which is an F-listed waste.
The roll applied chromic acid does not generate hazardous waste.
The hexavalent chromium emissions reported to TRI by the facility were not real emissions.  The emissions were calculated by using the same factor from the previous owner of the facility. The factor used was 0.5 percent of the prime coat applied was emitted as total chromium. Precoat bought several other facilities and they were also using this factor. No testing was ever conducted, and no analytical data exists to support the factor.
During the performance test for capture efficiency, they tested using a TTE, not a PTE.
To achieve a metal temperature of 400-500 degrees F the ovens operate at 700-900 degrees F.

Control Device
Both the prime and the finish coat booth emissions are routed to the same RTO.
For NSPS they needed to achieve more than 90% reduction, for MACT it is 98%, they operate at 98.4%. 
They do not need to supplement the RTO with natural gas, the solvent loading from coatings is adequate.
There are no operating costs associated with heating the oven due to recovery of heat from the RTO.
They have experienced a shortage of natural gas to SC, and during those times natural gas becomes more expensive.

Startup, Shutdown, and Malfunction
They described a sequenced shutdown procedure they would follow during malfunction, where they run the coil to the next stitch (next roll) and shut down.
The coater heads are interlocked with the RTO.
For both NSPS and MACT you must maintain a 3-hour block average. 
They stated they would not have a deviation unless they are 50 degrees below the set point temperature, as described by the NSPS.  For the 3-hour block average they assume zero control efficiency in accordance with the NESHAP.
They would add this to the average monthly emissions and calculate there is an exceedance of the emission limit (0.046 kg OHAP/liter solids applied).
They stated they would have no problem meeting the emission limit due to the extremely low emission rate they achieve with the RTO.

Electronic Reporting
The facility basically agreed with the need for electronic reporting.
They currently use NetDMR (Network Discharge Monitoring Report) on the CDX exchange.
They also use SLEIS, the SC State and Local Emissions Inventory System, to report emissions on a triannual basis for SC, an annual basis for WV, and triennially for AR. The states of IN and IL still require a paper submittal.

Periodic Testing
Precoat has facilities located nationwide that have periodic testing requirements, so this requirement would be nothing new. Periodic testing is required by SC every 4 years, WV every 5 years, AR every 5 years, TX every 10 years, and they have not tested in AL since 2005 (county).

Hour to Hour Variability
Variability occurs when a coating color/type is changed, production is stopped, or when the tanks and applicators are cleaned.
Emissions are lower (not higher) during this time since a mostly non-HAP solvent is used for cleaning. Solvent used is DR60 which is 98% acetone (not a VOC or HAP).
The RTO continues to run during the cleaning process.