Skip to main content

What if Industrial Flows Don't Make It to the Plant? Determining and Addressing Potential Water Quality Impacts of Non-Domestic Dischargers in a Combined Sewer System

Buy Article:

$9.50 plus tax (Refund Policy)

Or sign up for a free trial

The Sanitation District No. 1 of Northern Kentucky (SD1) entered into a Consent Decree (CD) with the USEPA, Region 4 and the State of Kentucky (EPPC) on April 18, 2007. The CD required SD1 to submit documentation to support compliance with the Nine Minimum Controls (NMCs) for combined sewer overflows, including NMC No. 3, the review and modification of pretreatment requirements to minimize the impacts of discharges into the combined sewer system (CSS) from non-domestic sources during wet weather and to minimize CSO occurrences by modifying the pretreatment program. To address this NMC, a thorough review of SD1's Pretreatment Program was performed leading to the development of several programs to better understand the effects of non-domestic dischargers (NDDs) on the CSS.

Within its pretreatment program, SD1 permits non-domestic dischargers (NDDs) classified as Significant Industrial Users (SIUs). NDDs are classified an SIU when they meet the guidelines in the Code of Federal Regulations and all other NDDs are classified as Non-Significant Users (NSUs). There are currently 5 SIUs and 740 NSUs in the CSS. Two separate programs were developed to analyze the potential water quality impacts from the NSUs and the SIUs within the combined sewer system.

A NSU is an industrial or commercial user that generally does not pose an obvious threat, potential harm, or a measurable impact to SD1's wastewater collection system or employees. However, groups or clusters of these industries that discharge like pollutants tributary to a particular CSO may contribute to higher than expected concentrations and therefore additional analyses were undertaken to determine the potential for impacts related to discharges into the CSS during wet weather events. An analysis identified six clusters of NSUs that discharge like pollutants. The pollutants of concern within each cluster, their process sources, and proposed action levels were determined and written guidelines developed outlining further evaluation by the SD1 Industrial Monitoring Department that may lead to permitting of additional industries.

For SIUs, a separate comprehensive analysis procedure was conducted that includes six different sequential steps incorporating eight different evaluations for each outfall/SIU combination. The analysis determined:

If WQS are being exceeded at the outfall


If the SIU permit limits are protective of WQS


If there is a risk of a particular SIU causing a water quality violation at the outfall


If a particular SIU is a major contributor to the pollutant load at the outfall


Recommendations for permit or process modifications


This paper details this innovative evaluation and the resulting modifications.
No Reference information available - sign in for access.
No Citation information available - sign in for access.
No Supplementary Data.
No Article Media
No Metrics

Keywords: Combined Sewer Overflows; Combined Sewer System; Non-Significant Users; Non-domestic Dischargers; Permit Limits; Significant Industrial Users; Synoptic Sampling; Water Quality Standards

Document Type: Research Article

Publication date: 2010-01-01

More about this publication?
  • Proceedings of the Water Environment Federation is an archive of papers published in the proceedings of the annual Water Environment Federation® Technical Exhibition and Conference (WEFTEC® ) and specialty conferences held since the year 2000. These proceedings are not peer reviewed.

    A subscription to the Proceedings of the Water Environment Federation includes access to most papers presented at the annual WEF Technical Exhibition and Conference (WEFTEC) and other conferences held since 2000. Subscription access begins 12 months after the event and is valid for 12 months from month of purchase. A subscription to the Proceedings of the Water Environment Federation is included in Water Environment Federation (WEF) membership.

    WEF Members: Sign in (right panel) with your IngentaConnect user name and password to receive complimentary access. Access begins 12 months after the conference or event
  • Subscribe to this Title
  • Membership Information
  • About WEF Proceedings
  • WEFTEC Conference Information
  • Learn about the many other WEF member benefits and join today
  • Ingenta Connect is not responsible for the content or availability of external websites
  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
X
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more