Ask the Expert Question-and-Answer Archive
(Wastewater Treatment)

by Mike McGinness, EcoShield Environmental Systems, Inc.
October, 2007

Listed as Metal Finishing Part 413, 433

Q. We have been listed as a metal finishing facility and would like to be removed from part 413, 433. The only "metal finishing" that is done here now is rust removal, which is removing iron. We used to have a zinc plating and tin palting operation, but that was removed from the facility. We have asked the city once to remove us from the Part 413, 433 however we are still being listed as a Metal Finishing facility Part 413, 433. Any suggestion on what we can do to show the city that we should not be listed as Part 413, 433?

A. I would just send them a registered, certified letter notifying them that your facility no longer has any Metal Finishing processes on site ( (1) assuming that is the case), telling them in the letter to remove your facility from the metal finishing category on their records and then keep a copy of the notice and mailing records on file.

Question: (1) How do you remove rust, what does the process include?

That said, if you ever plan to become a metal finisher again, you might want to consider remaining listed as a metal finisher now so as to remain regulated under the grandfathered, "existing source," regulations. If you exit the regulatory controls process now, and later want to go back to plating, you would need to meet the stricter "New Source" regulations.

Lastly, if you are using a water based process to clean or rinse the iron in the cleaning or rust removal process (as opposed to say dry sandblasting), and you delist your facility from the Metal Finishing category, you would need to list your facility under the new MP&M (Metal Products and Machinery) rule due the use of water in a metal cleaning process that discharges waste water from that process. Note that MP&M discharge limits for many metals are lower than the older Metal Finishing limits for existing sources. Once again, it may be to your advantage to stay a metal finisher under the older rules. I would suggest looking into the rust removal process, any other water based metal parts cleaning that takes place on site, and the relatively new MP&M rule as well the current Metal Finishing category (existing or new source) rules that you are currently regulated under, and then compare them to determine your best course of action.

Regards,

Mike McGinness