Presented in Partnership with:

Plain English Guide to Regulations
Wastewater Discharges

Prominent Electroplating or Metal Finishing Wastewater Issues

Zero Discharge Systems | Is Your Facility a New Source?


Zero Discharge Systems

waterWhat is a zero discharge system?

Zero discharge systems (also called closed-loop plating) use a combination of rinsing modifications, drag-out recovery, and wastewater treatment that allows a meta finishing or electroplating shop to reuse nearly 100 percent of all the water in a plating process line. In these systems, all wastewater is reclaimed and internally reused, so there is into discharge of wastewater.

Are there really zero discharges?

No. the “zero” refers only to the fact that no water is discharged. Often, there are air emissions (mostly water vapor) and solid wastes (spent filters, ion exchange resins. cathodes, etc). Metals in the solid wastes may be reclaimed.

Can metal finishers with zero discharge systems retire their Control Authority or NPDES permits?

Although, technically, you may have no discharge, you run a “regulatory risk” if you don’t have a wastewater discharge permit or agreement. Here’s why:

As a metal finishing shop, you are treating plating wastes and wastewaters that are considered to be listed and characteristic hazardous wastes. As a discharger with an NPDES permit or a Control Authority permit under the Clean Water Act, however, you are exempt from many of the hazardous waste treatment, storage, and disposal facility requirements under the Resource Conservation and Recovers’ Act (RCRA), notably the requirement to obtain a RCRA Part B permit. Simply put the EPA and your state environmental agency let you avoid parts of the RCRA program as long as you maintain some connection to a permitting authority or a Control Authority authorized under the Clean Water Act. It’s a matter of jurisdictional control. If you throw out your discharge permit, there’s no guarantee a RCRA inspector won’t come knocking on your door!

What can be done?

If you are considering installing a zero discharge system, discuss this with your Control Authority or permitting authority. Some Control Authorities and permitting authorities are issuing what they call “zero discharge permits.” Essentially, these recognize the fact that, with your current zero discharge configuration, you have no effluent discharges to either a POTW or to receiving waters; however, for oversight purposes only, the permit extends the CWA’s RCRA exemption to your facility.

Zero discharge permits may have reduced fees and few reporting or recordkeeping requirements. But they may require that your system be certified by a registered professional engineer, and this can cost several thousand dollars.

Is Your Facility a New Source?

Many electroplating job shops were originally regulated under the 40 CFR 413 electroplating regulations. Some of these facilities have unknowingly come under the more stringent 40 CFR 433 metal finishing regulations by subsequently meeting the definition of “new source.” For example, if you installed secondary containment after August 31, 1982 and it involved moving your tanks, you may be a new source and subject to the more stringent metal finishing standards.

A process constructed at an existing source job shop after August 31, 1982 is a new source if:

  • it entirely replaces a process which caused a discharge from an existing source, or
  • it is substantially independent of the existing sources on-site.

This means new source standards apply to the original installation of the metal finishing lines, rebuilt or moved lines, or existing lines converted to do new operations. This also means that the new source standards generally do not apply to the piecemeal replacement of tanks for maintenance in otherwise intact metal finishing lines, nor do they apply to treatment upgrades without altering production.The rule states that the new source standards apply when “an existing source undertakes major construction that legitimately provides it with the opportunity to install the best and most efficient production process and wastewater treatment technologies” (Fed Register, Vol. 53, No.200, October 17, 1988, p.40601).

Facilities that qualified to be regulated under the 413 electroplating standards, can add non-electroplating (see electroplating unit operations) metal finishing processes, such as heat treating without becoming a new source.Also, since no part of the facility qualifies under the metal finishing rule as a new source, the heat treat operation also does not qualify even if it was installed after it 1982. Therefore the heat treatment wastewater would not be regulated under federal regulations.

To help understand the new source definitions, take a look at these real life situations:

  • Secondary containment addition/new metal finishing process.Operations at this job shop began in 1978.In 1985, a spill release resulted in the removal of the entire shop, the installation of secondary containment and the reinstallation and replumbing of the metal finishing operations.In June 2005, the facility was inspected by the local sewer authority and subsequently by EPA Region 9.One of the conclusions from the inspections was that the facility was a new source due to the rebuilding of the plating lines in 1985 after installment of secondary containment.As such, the facility should have been meeting the 433 metal finishing standards, but they were not.As a result, the shop was issued an administrative order by EPA Region 9.
  • Secondary containment addition/new metal finishing process.This facility installed a secondary containment system approximately 20 years ago (i.e., after August 31, 1982), but since that work did not involve the removal of tanks, it did not affect the applicability of 413 standards.During a Federal EPA inspection in 2006, it was determined that this facility continues to qualify as a job shop.If it had involved the physical relocation and re-installation of entire lines, then that would qualify as construction that "legitimately provides it with the opportunity to install the best and most efficient production process and wastewater treatment this facility installed a dye penetrant line. Dye penetrant testing is unregulated under the job-shop electroplating rule in 40 CFR 413, but regulated under the metal finishing rule in 40 CFR 433 as an associated operation if other operations already qualify. Since no part of the facility qualifies under the metal finishing rule as a new source, the dye penetrant line also does not qualify even though it was installed after August 31, 1982. Therefore, the dye penetrant line is unregulated under the Federal categorical standards.
  • Arson fire caused moving plating lines into new building.At this job shop, an arson fire occurred in 1993, damaging one wall and a portion of the roof. The process equipment within the facility was undamaged by the fire. Because the site could not be adequately secured with perimeter fencing while the damage to the wall and roof was repaired, process equipment was removed and stored off-site until the repairs were complete and the building was secure. At that time, (with the concurrence of the sewer district) the same equipment which had been removed was reinstalled at the identical locations from which it had been removed. In this case, EPA ruled that the facility constructed new plating lines (under 40 CFR 403.3(k)(1)(ii)) using old components that had been the plating lines before the fire. The design and installation of the plating lines following the fire provided the facility with an opportunity to also design and install enhanced production equipment that would minimize the generation of pollutants.The movement of existing equipment in this example creates a new source because the construction and reassembly of the existing production equipment into the new or existing building provides an opportunity to design and install the best and most efficient production processes and wastewater treatment technologies.



The information contained in this site is provided for your review and convenience. It is not intended to provide legal advice with respect to any federal, state, or local regulation.
You should consult with legal counsel and appropriate authorities before interpreting any regulations or undertaking any specific course of action.

Please note that many of the regulatory discussions on STERC refer to federal regulations. In many cases, states or local governments have promulgated relevant rules and standards
that are different and/or more stringent than the federal regulations. Therefore, to assure full compliance, you should investigate and comply with all applicable federal, state and local regulations.