NASF Completes Metals Loading Study Highlighting Industry’s Clean Water Success

NASF has released a study pointing to the finishing industry’s major success in reducing metals discharges to local water treatment utilities in recent decades. The surface finishing industry is subject to two categorical standards for wastewater discharged to publicly owned treatment works (POTWs). In the past three years, the U.S. Environmental Protection Agency (EPA) has conducted a review of the categorical standards and discharge limits. During that time, the NASF has been working closely with EPA officials to provide information and analysis on the industry’s progress on wastewater discharge improvements.

Metals Loading Study

As part of an effort to develop useful data, NASF recently commissioned a metals loading study of wastewater discharged to the Milwaukee POTW. This study repeated a similar study conducted in 1992. The primary results of the study are summarized below.

  • The number of surface finishing facilities decreased from 104 in 1993 to 51 in 2016

  • The total metals discharged to the POTW were reduced by 87.6% since 1992

  • The average metals per facility discharged to the POTW were reduced by 72.0%

  • The surface finishing industry discharged only 2.1% of the metals discharged to the POTW in 2016

  • The number of facilities in Significant Non-Compliance decreased from 50% in 1989 to approximately 8% in 2016 (only 4 facilities)

Factors Driving Improved Environmental Performance

The study identified four general trends and reasons for the increase in environmental performance:

  • Facilities learned to operate their waste water treatment systems better over time

  • The better performing facilities survived the several economic downturns over the period between the studies

  • Facilities have better operational controls to maximize treatment efficiency

  • Facilities implemented pollution prevention practices that reduced the metals discharged

Based on the industry’s discussions with facilities and the wastewater utility community, these significant reductions are representative of surface finishing nationwide as the technology and science for managing wastewater treatment is fundamentally the same throughout the industry. This study clearly demonstrates that the surface finishing industry has made significant progress in reducing the metals in its effluent, providing evidence that revisions to the existing categorical standards for the industry are not needed at this time.

NASF has presented this information to EPA, and the agency is expected to make a final decision this summer on whether it will pursue revisions to the existing metal finishing and electroplating categorical standards and discharge limits.

If you have any questions or would like additional information about this study or EPA’s review of the existing waste water discharge standards, please contact Christian Richter or Jeff Hannapel with NASF at or




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